Turcot Syndrome


Turcot Syndrome is characterised by malignant tumors of the central nervous system (mostly astrocytomas and medulloblastoma) associated with familial polyposis of the colon. There are different sub-types (Paraf F et al, 1997).

Literature Analysis

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Tag cloud generated 08 August, 2015 using data from PubMed, MeSH and CancerIndex

Mutated Genes and Abnormal Protein Expression (5)

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MLH1 3p21.3 FCC2, COCA2, HNPCC, hMLH1, HNPCC2 Germline
-MLH1 mutations in Turcot Syndrome
PMS2 7p22.2 PMSL2, HNPCC4, PMS2CL Germline
-PMS2 mutations in Turcot Syndrome
APC 5q21-q22 GS, DP2, DP3, BTPS2, DP2.5, PPP1R46 Germline
-APC mutations in Turcot Syndrome
MSH2 2p21 FCC1, COCA1, HNPCC, LCFS2, HNPCC1 Germline
-MSH2 mutations in Turcot Syndrome
MSH6 2p16 GTBP, HSAP, p160, GTMBP, HNPCC5 Germline
-MSH6 mutations in Turcot Syndrome

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Useful Links (4 links)

Latest Publications

Durno CA, Sherman PM, Aronson M, et al.
Phenotypic and genotypic characterisation of biallelic mismatch repair deficiency (BMMR-D) syndrome.
Eur J Cancer. 2015; 51(8):977-83 [PubMed] Related Publications
Lynch syndrome, the most common inherited colorectal cancer syndrome in adults, is an autosomal dominant condition caused by heterozygous germ-line mutations in DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2. Inheriting biallelic (homozygous) mutations in any of the MMR genes results in a different clinical syndrome termed biallelic mismatch repair deficiency (BMMR-D) that is characterised by gastrointestinal tumours, skin lesions, brain tumours and haematologic malignancies. This recently described and under-recognised syndrome can present with adenomatous polyps leading to early-onset small bowel and colorectal adenocarcinoma. An important clue in the family history that suggests underling BMMR-D is consanguinity. Interestingly, pedigrees of BMMR-D patients typically show a paucity of Lynch syndrome cancers and most parents are unaffected. Therefore, a family history of cancers is often non-contributory. Detection of BMMR-D can lead to more appropriate genetic counselling and the implementation of targeted surveillance protocols to achieve earlier tumour detection that will allow surgical resection. This review describes an approach for diagnosis and management of these patients and their families.

Samdani T, Schultheis M, Stadler Z, et al.
Lymph node yield after colectomy for cancer: is absence of mismatch repair a factor?
Dis Colon Rectum. 2015; 58(3):288-93 [PubMed] Article available free on PMC after 01/03/2016 Related Publications
BACKGROUND: Nodal staging is crucial in determining the use of adjuvant chemotherapy for colon cancer. The number of metastatic lymph nodes has been positively correlated with the number of lymph nodes examined. Current guidelines recommend that at minimum 12 to 14 lymph nodes be assessed. In some studies, mismatch repair deficiency has been associated with lymph node yield.
OBJECTIVE: The purpose of this work was to determine whether mismatch repair-deficient colorectal tumors are associated with increased lymph node yield.
DESIGN: We queried an institutional database to analyze colectomy specimens with immunohistochemistry for mismatch repair genes in patients treated for colorectal cancer between 1999 and 2012. Before 2006, immunohistochemistry was performed at the request of an oncologist or surgeon. After 2006, it was routinely performed for patients <50 years of age. We measured the association of clinical and pathologic features with lymph node quantity. Fourteen predictors and confounders were jointly analyzed in a multivariable linear regression model.
SETTINGS: The study was conducted at a single tertiary care institution.
PATIENTS: Tissue specimens from 256 patients were reviewed.
MAIN OUTCOME MEASURES: The correlation of tumor, patient, and operative variables to the yield of mesenteric lymph nodes was measured.
RESULTS: Of 256 colectomy specimens reviewed, 94 had mismatch repair deficiency. On univariate analysis, mismatch repair deficiency was associated with lower lymph node yield, older patient age, right-sided tumors, and poor differentiation. The linear regression model identified 5 variables with independent relationships to lymph node yield, including patient age, specimen length, lymph node ratio, perineural invasion, and tumor size. A positive correlation was observed with tumor size, specimen length, and perineural invasion. Tumor location had a more complex, nonlinear, quadratic relationship with lymph node yield; proximal tumors were associated with a higher yield than more distal lesions. Mismatch repair deficiency was not independently associated with lymph node yield.
LIMITATIONS: Mismatch repair immunohistochemistry based on patient age, family history, and pathologic features may reduce the generalizability of these results. Our sample size was too small to identify variables with small measures of effect. The retrospective nature of the study did not permit a true assessment of the extent of mesenteric resection.
CONCLUSIONS: Patient age, length of bowel resected, lymph node ratio, perineural invasion, tumor size, and tumor location were significant predictors of lymph node yield. However, when controlling for surgical and pathologic factors, mismatch repair protein expression did not predict lymph node yield.

Murnyák B, Szepesi R, Hortobágyi T
[Molecular genetics of familial tumour syndromes of the central nervous system].
Orv Hetil. 2015; 156(5):171-7 [PubMed] Related Publications
Although most of the central nervous system tumours are sporadic, rarely they are associated with familial tumour syndromes. These disorders usually present with an autosomal dominant inheritance and neoplasia develops at younger age than in sporadic cases. Most of these tumours are bilateral, multiplex or multifocal. The causative mutations occur in genes involved in cell cycle regulation, cell growth, differentiation and DNA repair. Studying these hereditary cancer predisposition syndromes associated with nervous system tumours can facilitate the deeper understanding of the molecular background of sporadic tumours and the development of novel therapeutic agents. This review is an update on hereditary tumour syndromes with nervous system involvement with emphasis on molecular genetic characteristics and their clinical implications.

Newton K, Jorgensen NM, Wallace AJ, et al.
Tumour MLH1 promoter region methylation testing is an effective prescreen for Lynch Syndrome (HNPCC).
J Med Genet. 2014; 51(12):789-96 [PubMed] Related Publications
BACKGROUND AND AIMS: Lynch syndrome (LS) patients have DNA mismatch repair deficiency and up to 80% lifetime risk of colorectal cancer (CRC). Screening of mutation carriers reduces CRC incidence and mortality. Selection for constitutional mutation testing relies on family history (Amsterdam and Bethesda Guidelines) and tumour-derived biomarkers. Initial biomarker analysis uses mismatch repair protein immunohistochemistry and microsatellite instability. Abnormalities in either identify mismatch repair deficiency but do not differentiate sporadic epigenetic defects, due to MLH1 promoter region methylation (13% of CRCs) from LS (4% of CRCs). A diagnostic biomarker capable of making this distinction would be valuable. This study compared two biomarkers in tumours with mismatch repair deficiency; quantification of methylation of the MLH1 promoter region using a novel assay and BRAF c.1799T>A, p.(Val600Glu) mutation status in the identification of constitutional mutations.
METHODS: Tumour DNA was extracted (formalin fixed, paraffin embedded, FFPE tissue) and pyrosequencing used to test for MLH1 promoter methylation and presence of the BRAF c.1799T>A, p.(Val600Glu) mutation 71 CRCs from individuals with pathogenic MLH1 mutations and 73 CRCs with sporadic MLH1 loss. Specificity and sensitivity was compared.
FINDINGSS: Unmethylated MLH1 promoter: sensitivity 94.4% (95% CI 86.2% to 98.4%), specificity 87.7% (95% CI 77.9% to 94.2%), Wild-type BRAF (codon 600): sensitivity 65.8% (95% CI 53.7% to 76.5%), specificity 98.6% (95% CI 92.4% to 100.0%) for the identification of those with pathogenic MLH1 mutations.
CONCLUSIONS: Quantitative MLH1 promoter region methylation using pyrosequencing is superior to BRAF codon 600 mutation status in identifying constitutional mutations in mismatch repair deficient tumours.

Chou A, Toon CW, Clarkson A, et al.
Loss of ARID1A expression in colorectal carcinoma is strongly associated with mismatch repair deficiency.
Hum Pathol. 2014; 45(8):1697-703 [PubMed] Related Publications
ARID1A is a tumor suppressor gene involved in chromatin remodelling. ARID1A mutations and loss of protein expression occur commonly in endometrioid and gynecological clear cell carcinoma where they are associated with mismatch repair (MMR) deficiency. We assessed ARID1A expression in a large cohort of colorectal carcinomas (CRCs). Immunohistochemistry for ARID1A was performed on whole sections from 100 CRCs and on 1876 CRCs in tissue microarray format. There was complete concordance between the staining on whole slides and tissue microarray sections. Loss of staining was found in 110 (5.9%) of 1876 CRCs and was strongly associated with older age, right sided location, large size, BRAF V600E mutation, MMR deficiency, high histological grade and medullary morphology, (all P < .01). There was a trend towards loss of expression being more common in females (P = .06). When subclassified by combined BRAF V600E mutation and MMR status, loss of ARID1A expression was found most commonly in CRCs with the BRAF V600E mutated, MMR- deficient phenotype (58 of 232 cases, 25%, P < .01). In univariate and multivariate analysis, loss of ARID1A expression was not associated with overall survival-hazard ratio 1.05 (0.68-1.64) and 0.60 (0.24-1.44), respectively. All carcinomas arising in patients with known Lynch syndrome (n = 12) were ARID1A positive. We conclude that loss of ARID1A expression occurs in a small but significant proportion of CRCs where it is strongly correlated with mismatch repair deficiency and other clinical and pathological features associated with somatic hypermethylation.

Wimmer K, Kratz CP, Vasen HF, et al.
Diagnostic criteria for constitutional mismatch repair deficiency syndrome: suggestions of the European consortium 'care for CMMRD' (C4CMMRD).
J Med Genet. 2014; 51(6):355-65 [PubMed] Related Publications
Constitutional mismatch repair deficiency (CMMRD) syndrome is a distinct childhood cancer predisposition syndrome that results from biallelic germline mutations in one of the four MMR genes, MLH1, MSH2, MSH6 or PMS2. The tumour spectrum is very broad, including mainly haematological, brain and intestinal tract tumours. Patients show a variety of non-malignant features that are indicative of CMMRD. However, currently no criteria that should entail diagnostic evaluation of CMMRD exist. We present a three-point scoring system for the suspected diagnosis CMMRD in a paediatric/young adult cancer patient. Tumours highly specific for CMMRD syndrome are assigned three points, malignancies overrepresented in CMMRD two points and all other malignancies one point. According to their specificity for CMMRD and their frequency in the general population, additional features are weighted with 1-2 points. They include multiple hyperpigmented and hypopigmented skin areas, brain malformations, pilomatricomas, a second childhood malignancy, a Lynch syndrome (LS)-associated tumour in a relative and parental consanguinity. According to the scoring system, CMMRD should be suspected in any cancer patient who reaches a minimum of three points by adding the points of the malignancy and the additional features. The diagnostic steps to confirm or refute the suspected diagnosis are outlined. We expect that application of the suggested strategy for CMMRD diagnosis will increase the number of patients being identified at the time when they develop their first tumour. This will allow adjustment of the treatment modalities, offering surveillance strategies for second malignancies and appropriate counselling of the entire family.

Gorovoy IR, de Alba Campomanes A
A potential life-saving diagnosis--recognizing Turcot syndrome.
J AAPOS. 2014; 18(2):186-8 [PubMed] Related Publications
A previously healthy 9-year-old girl presented with ataxia, headaches, and nausea of 1 month's duration. Magnetic resonance imaging demonstrated a large posterior fossa mass. Posterior segment examination revealed pigmented ocular fundus lesions (POFLs), which included cometoid dark lesions with depigmented tails and smaller, dark midperipheral lesions. The patient underwent resection for a medulloblastoma. Because of these specific retinal lesions in combination with her medullobastoma, a diagnosis of Turcot syndrome was made and subsequently confirmed by genetic testing. Turcot syndrome is one of the familial adenomatous polyposis (FAP) syndromes. This diagnosis may be life-saving because 100% of FAP patients develop colon cancer that can be cured only early with timely colectomy.

Mensenkamp AR, Vogelaar IP, van Zelst-Stams WA, et al.
Somatic mutations in MLH1 and MSH2 are a frequent cause of mismatch-repair deficiency in Lynch syndrome-like tumors.
Gastroenterology. 2014; 146(3):643-646.e8 [PubMed] Related Publications
Lynch syndrome is caused by germline mutations in the mismatch repair (MMR) genes. Tumors are characterized by microsatellite instability (MSI). However, a considerable number of MSI-positive tumors have no known molecular mechanism of development. By using Sanger and ion semiconductor sequencing, 25 MSI-positive tumors were screened for somatic mutations and loss of heterozygosity in mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2). In 13 of 25 tumors (8 MLH1-deficient and 5 MSH2-deficient tumors), we identified 2 somatic mutations in these genes. We conclude that 2 acquired events explain the MMR-deficiency in more than 50% of the MMR-deficient tumors without causal germline mutations or promoter methylation.

Hegde M, Ferber M, Mao R, et al.
ACMG technical standards and guidelines for genetic testing for inherited colorectal cancer (Lynch syndrome, familial adenomatous polyposis, and MYH-associated polyposis).
Genet Med. 2014; 16(1):101-16 [PubMed] Related Publications
Lynch syndrome, familial adenomatous polyposis, and Mut Y homolog (MYH)-associated polyposis are three major known types of inherited colorectal cancer, which accounts for up to 5% of all colon cancer cases. Lynch syndrome is most frequently caused by mutations in the mismatch repair genes MLH1, MSH2, MSH6, and PMS2 and is inherited in an autosomal dominant manner. Familial adenomatous polyposis is manifested as colonic polyposis caused by mutations in the APC gene and is also inherited in an autosomal dominant manner. Finally, MYH-associated polyposis is caused by mutations in the MUTYH gene and is inherited in an autosomal recessive manner but may or may not be associated with polyps. There are variants of both familial adenomatous polyposis (Gardner syndrome--with extracolonic features--and Turcot syndrome, which features medulloblastoma) and Lynch syndrome (Muir-Torre syndrome features sebaceous skin carcinomas, and Turcot syndrome features glioblastomas). Although a clinical diagnosis of familial adenomatous polyposis can be made using colonoscopy, genetic testing is needed to inform at-risk relatives. Because of the overlapping phenotypes between attenuated familial adenomatous polyposis, MYH-associated polyposis, and Lynch syndrome, genetic testing is needed to distinguish among these conditions. This distinction is important, especially for women with Lynch syndrome, who are at increased risk for gynecological cancers. Clinical testing for these genes has progressed rapidly in the past few years with advances in technologies and the lower cost of reagents, especially for sequencing. To assist clinical laboratories in developing and validating testing for this group of inherited colorectal cancers, the American College of Medical Genetics and Genomics has developed the following technical standards and guidelines. An algorithm for testing is also proposed.

Fritch Lilla SA, Yi JS, Hall BA, Moertel CL
A novel APC gene mutation associated with a severe phenotype in a patient with Turcot syndrome.
J Pediatr Hematol Oncol. 2014; 36(3):e177-9 [PubMed] Related Publications
Turcot syndrome is a rare inherited condition of colonic polyposis associated with central nervous system tumors. We report a patient with a novel adenomatous polyposis coli gene mutation leading to a severe phenotype including medulloblastoma, low-grade fibromyxoid sarcoma following cranial radiation, pilomatrixomas, colonic adenomas, and abdominal desmoid tumor following colectomy, all of which were successfully treated. Multiple tumors may be seen in patients with Turcot syndrome but the occurrence of sarcomas is rare. This case highlights the importance of close follow-up for patients with Turcot syndrome and the importance of a broad differential diagnosis in evaluating a condition in which multiple tumors are frequently seen.

Ozerov SS, Zakharov IV, Talypov SR, et al.
[Turcot syndrome. Rare observation and literature review].
Zh Vopr Neirokhir Im N N Burdenko. 2013; 77(3):49-53; discussion 53 [PubMed] Related Publications
The Turcot syndrome is a rare disease which is characterized by a combination of a brain tumor with a y at which the neoplasm of the colon. About 150 of such observations are described in world literature. Our own observation and a literature review are presented in this article.

Cazorla A, Viennet G, Uro-Coste E, Valmary-Degano S
Mucoepidermoid carcinoma: A yet unreported cancer associated with familial adenomatous polyposis.
J Craniomaxillofac Surg. 2014; 42(3):262-4 [PubMed] Related Publications
Turcot's syndrome is a rare clinical syndrome, characterized by the association between familial adenomatous polyposis (FAP) and a primary central nervous system tumour. Gardner's syndrome is characterized by the association between FAP and several tumour types such as multiple osteomas, fibromas, epidermoid cysts and desmoid tumours. We report here the case of a twenty-six year-old woman with a history of both Turcot's and Gardner syndromes. She had a family history of adenomatous polyposis with a mutation in the APC (Adenomatous Polyposis Coli) gene. At the age of 26, she presented a mucoepidermoid carcinoma of the right parotid gland in which the MECT1-MAML2 fusion was showed. We discuss the possible addition of this latter cancer type in the definition of Gardner's syndrome.

Stefanaki K, Alexiou GA, Stefanaki C, Prodromou N
Tumors of central and peripheral nervous system associated with inherited genetic syndromes.
Pediatr Neurosurg. 2012; 48(5):271-85 [PubMed] Related Publications
There are several genetic syndromes that predispose to the development of tumors of the nervous system. In the present study, we provide a review of the tumors that are associated with neurofibromatosis type 1, neurofibromatosis type 2, tuberous sclerosis complex, von Hippel-Lindau disease, Li-Fraumeni syndrome, Cowden disease, Turcot syndrome, nevoid basal cell carcinoma syndrome (Gorlin syndrome) and rhabdoid predisposition syndrome, which are the most common.

Walter AW, Ennis S, Best H, et al.
Constitutional mismatch repair deficiency presenting in childhood as three simultaneous malignancies.
Pediatr Blood Cancer. 2013; 60(11):E135-6 [PubMed] Related Publications
A 13-year-old child presented with three simultaneous malignancies: glioblastoma multiforme, Burkitt lymphoma, and colonic adenocarcinoma. She was treated for her diseases without success and died 8 months after presentation. Genetic analysis revealed a homozygous mutation in the PMS2 gene, consistent with constitutional mismatch repair deficiency. Her siblings and parents were screened: three of four siblings and both parents were heterozygous for this mutation; the fourth sibling did not have the mutation.

Chmara M, Wernstedt A, Wasag B, et al.
Multiple pilomatricomas with somatic CTNNB1 mutations in children with constitutive mismatch repair deficiency.
Genes Chromosomes Cancer. 2013; 52(7):656-64 [PubMed] Related Publications
Constitutional mismatch repair deficiency (CMMR-D) due to biallelic germline mutations in one of four mismatch repair genes causes a childhood cancer syndrome characterized by a broad tumor spectrum including hematological malignancies, and brain and Lynch syndrome-associated tumors. Herein, we report three children who had in addition to CMMR-D-associated malignancies multiple pilomatricomas. These are benign skin tumors of hair matrical differentiation frequently associated with somatic activating mutations in the ß-catenin gene CTNNB1. In two of the children, the diagnosis of CMMR-D was confirmed by the identification of biallelic germline PMS2 mutations. In the third individual, we only found a heterozygous germline PMS2 mutation. In all nine pilomatricomas with basophilic cells, we detected CTNNB1 mutations. Our findings indicate that CTNNB1 is a target for mutations when mismatch repair is impaired due to biallelic PMS2 mutations. An elevated number of activating CTNNB1 alterations in hair matrix cells may explain the development of multiple pilomatricomas in CMMR-D patients. Of note, two of the children presented with multiple pilomatricomas and other nonmalignant features of CMMR-D before they developed malignancies. To offer surveillance programs to CMMR-D patients, it may be justified to suspect CMMR-D syndrome in individuals fulfilling multiple nonmalignant features of CMMR-D (including multiple pilomatricomas) and offer molecular testing in combination with interdisciplinary counseling.

Brierley DJ, Martin SA
Oxidative stress and the DNA mismatch repair pathway.
Antioxid Redox Signal. 2013; 18(18):2420-8 [PubMed] Related Publications
SIGNIFICANCE: Living organisms are under constant assault by a combination of environmental and endogenous oxidative DNA damage, inducing the modification of proteins, lipids, and DNA. Failure to resolve these oxidative modifications is associated with genome instability and the development of many disease states. To maintain genomic integrity, oxidative lesions must be precisely targeted and efficiently resolved. For this, cells have evolved an intricate network of DNA repair mechanisms to detect and repair oxidative DNA damage.
RECENT ADVANCES: Emerging evidence suggests that in addition to the base excision repair and nucleotide excision repair pathways, the DNA mismatch repair (MMR) pathway plays an important role in mediating oxidative DNA damage repair. Studies in lower organisms and mammalian cells have enabled us to further dissect this critical role and elucidate the precise mechanisms of repair.
CRITICAL ISSUES: Identification of synthetic lethal interactions between MMR deficiency and the accumulation of oxidative DNA damage raises the tantalizing prospect that oxidative DNA-damaging agents may be utilized to selectively target MMR-deficient cancers and potentially other tumor types deficient for oxidative DNA repair molecules.
FUTURE DIRECTIONS: In this review, we emphasize the clinical relevance and potential translation of exploiting this oxidative DNA repair mechanism using synthetic lethality studies in MMR-deficient cells, to develop improved treatment strategies that will benefit cancer patients.

Steinhagen E, Moore HG, Lee-Kong SA, et al.
Patients with colorectal and renal cell carcinoma diagnoses appear to be at risk for additional malignancies.
Clin Colorectal Cancer. 2013; 12(1):23-7 [PubMed] Related Publications
UNLABELLED: Patients with colorectal cancer (CRC) and renal cell carcinoma (RCC) may be at risk for additional primary malignancies. A review of 101 patients with these concurrent diagnoses was performed. Forty-two percent of patients had 1 or more additional malignancies; none appeared to be associated with Lynch syndrome (LS). This suggests the need for careful follow-up in these patients and further study.
BACKGROUND: Small studies have demonstrated that patients who have both colorectal and renal cell carcinoma may be at increased risk for the development of additional malignancies. A possible genetic basis has been suggested. Our study describes the clinicopathologic features of these patients and clarifies the relationship of this cohort with Lynch syndrome (LS).
METHODS: Patients with primary CRC and RCC treated at our institution were identified. Medical records were reviewed for demographic and clinical information. Immunohistochemical staining for mismatch repair (MMR) proteins was performed on tumor tissue when possible.
RESULTS: During the study period, 24,642 patients were treated for CRC and 7,366 were treated for RCC at our institution. One hundred seventy-nine patients had both diagnoses, with 101 patients eligible for inclusion in our cohort. Tumors were typically early stage. The 2 cancers presented as synchronous lesions in 42% of patients. Thirty-two patients had 1 additional primary malignancy, 7 patients had 2 additional primary malignancies, and 3 patients had 3 additional primary malignancies. No patient had a family history that met the Amsterdam II criteria (AC) for LS, but 50% had family members with 1 malignancy. One of 10 colorectal tumors analyzed for the absence of MMR protein expression demonstrated the absence of MSH6, but the corresponding RCC demonstrated intact expression of all 4 MMR proteins.
CONCLUSION: It is rare for patients to be diagnosed with both CRC and RCC. The clinicopathologic features of this cohort and the results of immunohistochemical analysis performed on a sample of these patients do not suggest LS. However, the high rate of additional carcinomas suggests a need for careful follow-up. Multicenter longitudinal studies are warranted to further understand the natural history and possible genetic basis for this entity.

Ma S, Hu Y, Yang J, Zhou X
Turcot's syndrome associated with intestinal non-Hodgkin's lymphoma: case report and review of literature.
Clin Neurol Neurosurg. 2013; 115(2):117-20 [PubMed] Related Publications
A 15-year-old boy was admitted with the diagnosis of colonic polyposis, and during a 2-year follow-up, he underwent operation for right parieto-occipital anaplastic astrocytoma, left-side colonic non-Hodgkin lymphoma (NHL) and cerebella glioblastoma which were all confirmed by histology. Although cases of Turcot's syndrome (TS) (colonic polyposis and primary brain tumour occurring in the same patient) have been previously described, association with haematological malignancy is rare. We hereby report such a case with TS.

Kleinerman R, Marino J, Loucas E
Muir-Torre Syndrome / Turcot Syndrome overlap? A patient with sebaceous carcinoma, colon cancer, and a malignant astrocytoma.
Dermatol Online J. 2012; 18(5):3 [PubMed] Related Publications
The Muir-Torre Syndrome is characterized by the clinical constellation of sebaceous neoplasms, keratoacanthomas, and internal malignancies caused by a defect in DNA mismatch repair. Another mismatch repair defect causes Turcot syndrome, which manifests with colorectal and central nervous system neoplasms. We wish to report a case in which the manifestations of both syndromes were observed in the same patient. We further discuss the possible genetic basis for this overlap.

Fuseya C, Horiuchi A, Hayashi A, et al.
Involvement of pelvic inflammation-related mismatch repair abnormalities and microsatellite instability in the malignant transformation of ovarian endometriosis.
Hum Pathol. 2012; 43(11):1964-72 [PubMed] Related Publications
Inflammation in the ovary, including ovulation and pelvic inflammatory disease, has been proposed to play a role in the pathogenesis of ovarian cancer. Endometriotic lesions trigger a local inflammatory reaction and have been reported to be associated with an increased risk of epithelial ovarian cancer. However, the precise molecular mechanisms of ovarian cancer arising from endometriosis are still to be elucidated. To clarify the involvement of mismatch repair (MMR) abnormalities in the inflammation-associated malignant transformation of endometriosis, the immunohistochemical expression of mismatch repair proteins (human mutL homolog 1 [hMLH1] and human mutS homolog 2 [hMSH2]) was examined in 27 cases of ovarian endometriosis, 25 cases of ovarian carcinoma accompanied by endometriosis, and 39 cases of solitary ovarian carcinoma. In addition, the relationship between mismatch repair abnormalities including the microsatellite instability, PTEN (phosphatase and tensin homolog) mutation, and clinicopathologic parameters was analyzed. The expression of mismatch repair proteins was stepwisely decreased in endometriosis, ovarian carcinoma accompanied by endometriosis, and ovarian carcinoma. Tumors harboring multiple microsatellite instability (high-frequency microsatellite instability [MSI-H]) were detected in 4 (14.8%) of 27 cases of endometriosis and 7 (30.4%) of 23 cases of ovarian carcinomas. The frequency of PTEN mutations was higher in MSI-H cases than in microsatellite instability-stable (MSI-S) cases. In 2 cases of ovarian carcinoma accompanied by endometriosis, the decreased expression of mismatch repair proteins and MSI-H was observed in both the endometriosis and carcinoma lesions. Clinicopathologically, the MSI-H cases were associated with elevated serum levels of C-reactive protein and higher white blood cell counts. These findings suggest that mismatch repair abnormalities might be involved in the malignant transformation of ovarian endometriosis and that inflammation induces mismatch repair abnormalities during ovarian carcinogenesis arising from endometriosis.

Albuquerque C, Bakker ER, van Veelen W, Smits R
Colorectal cancers choosing sides.
Biochim Biophys Acta. 2011; 1816(2):219-31 [PubMed] Related Publications
In contrast to the majority of sporadic colorectal cancer which predominantly occur in the distal colon, most mismatch repair deficient tumours arise at the proximal side. At present, these regional preferences have not been explained properly. Recently, we have screened colorectal tumours for mutations in Wnt-related genes focusing specifically on colorectal location. Combining this analysis with published data, we propose a mechanism underlying the side-related preferences of colorectal cancers, based on the specific acquired genetic defects in β-catenin signalling.

Jasperson KW, Samowitz WS, Burt RW
Constitutional mismatch repair-deficiency syndrome presenting as colonic adenomatous polyposis: clues from the skin.
Clin Genet. 2011; 80(4):394-7 [PubMed] Related Publications
Constitutional mismatch repair-deficiency (CMMR-D) syndrome is an autosomal recessive condition characterized by hematologic malignancies, brain tumors, Lynch syndrome-associated cancers and skin manifestations reminiscent of neurofibromatosis type 1 (NF1). In contrast to Lynch syndrome, CMMR-D syndrome is exceptionally rare, onset typically occurs in infancy or early childhood and, as described in this report, may also present with colonic polyposis suggestive of attenuated familial adenomatous polyposis (AFAP) or MUTYH associated polyposis (MAP). Here we describe two sisters with CMMR-D syndrome due to germline bi-allelic MSH6 mutations. Both sisters are without cancer, are older than typical for this condition, have NF1 associated features and a colonic phenotype suspicious for an attenuated polyposis syndrome. This report highlights the role of skin examinations in leading to an underlying genetic diagnosis in individuals with colonic adenomatous polyposis, but without mutations associated with AFAP or MAP.

Lusis EA, Travers S, Jost SC, Perry A
Glioblastomas with giant cell and sarcomatous features in patients with Turcot syndrome type 1: a clinicopathological study of 3 cases.
Neurosurgery. 2010; 67(3):811-7; discussion 817 [PubMed] Related Publications
BACKGROUND: Turcot syndrome (TS) is a rare genetic disorder of DNA mismatch repair predisposing to glioblastoma (GBM) in the type 1 variant.
OBJECTIVE: We report the clinicopathological and genetic features of 3 gliomas in TS type 1 patients.
METHODS: Three cases were reviewed from our clinical and pathology files at Washington University with the diagnosis of TS 1 and GBM over the past 14 years. All 3 had classic features of GBM, but also demonstrated bizarre multinucleated giant cells and remarkably high mitotic indices. Sarcomatous regions were found in 2. Despite these features, the patients had prolonged survival times of 44, 55, and >29 months (ie, currently alive). Demographic and clinical courses were abstracted from retrospective chart review. Histopathology was reviewed from all cases and reticulin histochemistry was added to identify possible foci of sarcomatous differentiation.
RESULTS: All 3 had classic features of GBM, and Ki-67 labeling indices ranged from 18 to 45%. All 3 also showed strong nuclear p53 positivity. Two cases were negative for the isocitrate dehydrogenase 1 (IDH1) mutation, and O-Methylguanine methyltransferase promoter methylation was seen in one. Fluorescence in situ hybridization was done using 1p/1q, 19p/19q, centromere 7/epithelial growth factor receptor (EGFR), and PTEN/DMBT1 probes. Focal EGFR amplification was seen in one case, although other common alterations of either primary GBMs or gliomas with prolonged survival (1p/19q codeletion) were lacking.
CONCLUSION: We conclude that 1) the giant cell variant of GBM is overrepresented in TS; 2) gliosarcomas may also be encountered; and 3) survival is often favorable, despite histological anaplasia and exuberant proliferation.

Juhn E, Khachemoune A
Gardner syndrome: skin manifestations, differential diagnosis and management.
Am J Clin Dermatol. 2010; 11(2):117-22 [PubMed] Related Publications
Gardner syndrome is a variant of familial adenomatous polyposis (FAP) and results in the manifestation of numerous external and internal symptoms including gastrointestinal polyps, osteomas, tumors, and epidermoid cysts. As such, it is highly recommended that physicians conduct full body examinations to catch the key clinical features of the disease when it is suspected. Stemming from a mutation in the adenomatous polyposis coli (APC) gene, Gardner syndrome shares genetic correlations with the FAP phenotype; as a result, it becomes all the more crucial for physicians to be able to discern Gardner syndrome from other differential diagnoses such as Turcot syndrome, FAP, and other attenuated forms of familial polyposis. Fortunately, Gardner syndrome has characteristic polyps in the colon, osteomas, and also exhibits abnormalities in the retinal epithelium that discern it from others. Surgery is the most effective method of management for Gardner syndrome; restorative proctocolectomy with ileal pouch anal anastomosis with mucosectomy is the top choice for colonic malignancies, and skin manifestations can be treated through a variety of excisions and therapy depending on location, size, and number of malignancies. Currently, there are no specific screening recommendations for Gardner syndrome, but testing following general screening recommendations for extra-colonic malignancies, genetic counseling, and endoscopy are encouraged.

Hottinger AF, Khakoo Y
Neurooncology of familial cancer syndromes.
J Child Neurol. 2009; 24(12):1526-35 [PubMed] Related Publications
The majority of tumors of the nervous system are sporadic. However, a subset of patients with tumors and their families are predisposed to developing cancers of the central nervous system and other organs because of a germline mutation. In the last decade, many of the genes responsible for these typically autosomal dominant familial tumor syndromes have been identified. Additionally, our understanding of the mechanisms of carcinogenesis in these syndromes has increased, allowing for more targeted therapies for these patients as well as those with sporadic cancers. Because these patients present a unique set of issues regarding diagnosis and neurooncological management, the most common familial cancer syndromes involving the nervous system are reviewed: neurofibromatosis type 1 and 2; tuberous sclerosis complex; von Hippel Lindau, Li-Fraumeni, Gorlin, and Turcot syndrome.

Baehring J, Hui P, Piepmeier J, Bannykh SI
Anaplastic oligoastrocytoma in Turcot syndrome.
J Neurooncol. 2009; 95(2):293-8 [PubMed] Related Publications
Turcot syndrome (TS), a rare variant of hereditary non-polyposis colorectal cancer (HNPCC), is characterized by familial clustering of cancer of the large bowel, extracolonic body sites and brain. It is caused by germline mutations in genes encoding for components of the DNA mismatch repair system. We report a 72 year old woman with anaplastic oligoastrocytoma in the setting of TS. Careful analysis of tumor DNA is required to exclude the chance occurrence of a brain tumor in HNPCC kindreds and increase our understanding of the pathogenesis of the disease. Our case adds to the handful of cases published with detailed molecular data previously.

Edlich R, Cross CL, Wack CA, et al.
Revolutionary advances in the diagnosis and treatment of Familial Adenomatous Polyposis.
J Environ Pathol Toxicol Oncol. 2009; 28(1):47-52 [PubMed] Related Publications
During the last 25 years, there have been revolutionary advances in the treatment of Familial Adenomatous Polyposis (FAP). The purpose of this article is to describe the pathophysiology, genetic testing, surveillance, surgical interventions, and psychosocial issues. The genetic defect in FAP is germline mutation in the adenomatous polyposis coli (APC) gene. Syndromes once thought to be distinct from FAP are now recognized to be part of the phenotypic spectrum of FAP. Syndromes with a germline mutation in the APC gene include FAP, Gardner syndrome, Turcot syndrome, and Attenuated Adenomatous Polyposis Coli (AAPC). FAP is a germline mutation in the APC gene with onset of florid polyposis in childhood and development of colorectal cancer by age 30. Colectomy is advised because of the high risk of developing colorectal cancer. AAPC is a variant of this condition with later age of onset and milder clinical phenotype. However, colectomy is advised once polyposis develops and polyps cannot be managed endoscopically. Despite the unique advances in genetic testing, psychosocial management of these syndromes remains to be a challenging problem.

Reuss D, von Deimling A
Hereditary tumor syndromes and gliomas.
Recent Results Cancer Res. 2009; 171:83-102 [PubMed] Related Publications
Several congenital syndromes caused by germline mutations in tumor suppressor genes predispose to the development of glial tumors. In the last few decades our knowledge about the molecular functions of these genes and the pathogenesis of hereditary tumor syndromes has greatly increased. The most common syndromes are the neurofibromatoses (type 1 and type 2) and the tuberous scleroses complex. There are interesting overlaps in the molecular pathogen-esis. Deregulation of Ras or downstream Ras pathways including MEK/ERK and AKT/ mTOR plays an important role in these three syndromes. Other rare syndromes include Li-Fraumeni, melanoma-astrocytoma, and Turcot syndrome involving cell cycle regulators and DNA repair genes. The genes and pathways involved in the pathogenesis of these syndromes also play an important role in the development of sporadic tumors. Therefore research on hereditary syndromes contributes substantially to our understanding of tumor formation.

Giunti L, Cetica V, Ricci U, et al.
Type A microsatellite instability in pediatric gliomas as an indicator of Turcot syndrome.
Eur J Hum Genet. 2009; 17(7):919-27 [PubMed] Article available free on PMC after 01/03/2016 Related Publications
Microsatellite instability (MSI) is present in hereditary conditions due to mismatch repair (MMR) gene mutations. Following MSI analysis, tumor samples are classified into MSS (stable), MSI-L (low instability), and MSI-H (high instability) based on the fraction of unstable loci. Another MSI-based classification takes into account the size difference between mutant alleles in tumor DNA compared to wild-type alleles; two types of MSI, A and B, are recognized using this approach, type A being characterized by smaller, more subtle allelic shifts compared to type B. Biallelic mutations of MMR genes are associated with pediatric cancers, including glial tumors, in Turcot syndrome type 1 (TS1). However, most TS1-associated gliomas so far analyzed did not display MSI. We investigated the frequency of MSI in a series of 34 pediatric gliomas of different grade using a panel of five mononucleotide quasimonomorphic markers. Subtle qualitative changes were observed for the majority of markers in two glioblastomas (5.9% of the total series and 33.3% of glioblastomas). In both cases, family histories were compatible with TS1, and mutations of the PMS2 and MLH1 genes were identified. In one family, the MSI patterns were compared between the glioblastoma and a colon cancer from an affected relative, showing a clear qualitative difference, with the former displaying type A and the latter type B instability, respectively. These results were confirmed using additional microsatellite markers, indicating that knowledge of the association between TS1-related glial tumors and subtle type A MSI is important for full ascertainment of TS1 patients and appropriate counselling.

Sjursen W, Bjørnevoll I, Engebretsen LF, et al.
A homozygote splice site PMS2 mutation as cause of Turcot syndrome gives rise to two different abnormal transcripts.
Fam Cancer. 2009; 8(3):179-86 [PubMed] Related Publications
Turcot syndrome is a rare, inherited disease predisposing of tumours in the central nerve system and in the colorectal system. This report describes a Turcot patient with an extraordinary clinical history. The patient is still alive at the age of 43. She was operated at the age of 10 by brain tumour and at the age of 16 by colorectal cancer. She has since then been treated for multiple cancers (gastrointestinal, endometrial, basal cell carcinomas), and removal of adenomatous polyps at several occasions. The aim of this work was to investigate if there was any specific genotype that explains her remarkable clinical history. Microsatellite instability and immunohistochemistry analysis for four DNA mismatch repair proteins were performed. DNA mutation analysis was done for genes involved in polyposis and mismatch repair by denaturing high performance liquid chromatography and sequencing. cDNA analysis was carried out for the mismatch repair gene PMS2. The patients genotype was found to be a homozygous splice site mutation in the PMS2 gene, c.989-1G

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