Inbal Kedar

Upper and lower gastrointestinal findings in PTEN mutation-positive Cowden syndrome patients participating in an active surveillance program

OBJECTIVES:Cowden syndrome (CS), associated with germline PTEN mutations, is an autosomal-dominant disorder with increased frequencies of thyroid and breast cancers. Recent reports document the occurrence of gastrointestinal (GI) polyps and increased risk of colon cancer in PTEN mutation carriers. Studies to date, however, have not been based on mutation carriers undergoing active, systematic, routine-interval GI surveillance. Our objective is to document the upper and lower GI findings in CS patients undergoing such an active GI surveillance program.METHODS:In a 5-year period, 3,000 consecutive patients were referred to our high-risk GI cancer clinic for various reasons. Of these 3,000, 10 met full-blown clinical criteria for the diagnosis of CS. Individuals with identified PTEN mutations underwent annual upper and lower endoscopy surveillance programs using dual white light and narrow-band imaging. All biopsies including archived materials were reviewed by a single dedicated GI pathologist.RESULTS:Ten PTEN mutation carriers from different ethnic backgrounds were invited and all participated in the active GI surveillance program. Eight patients had colonic polyps, mostly hyperplastic (eight patients) and hamartomatous (five patients), but also adenomatous (three patients), ganglioneuromatous (three patients), and juvenile polyps (two patients). One patient (10%) had an early-onset rectal cancer (aged 44 years), which was null for PTEN expression on immunohistochemistry. All patients had gastric polyps and nine (90%) had duodenal polyps, mostly hyperplastic and hamartomatous. Additional three patients (30%) had adenomatous duodenal polyps.CONCLUSIONS:PTEN mutation–positive CS patients have a higher frequency of upper GI polyps than previously believed. They appear prone to develop adenomatous upper and lower tract dysplastic polyps and cancer. Thus, the polyps encountered during upper or lower endoscopy in these patients should not be automatically considered innocent hamartomas without malignant potential. Active surveillance programs in specialized centers should be considered in these patients.

An Ashkenazi founder mutation in the MSH6 gene leading to HNPCC.

Mutations in DNA mismatch repair genes underlie lynch syndrome (HNPCC). Lynch syndrome resulting from mutations in MSH6 is considered to be attenuated in comparison to that caused by mutations in MLH1 and MSH2, thus more likely to be under diagnosed. In this study we report of a common mutation in the MSH6 gene in Ashkenazi Jews. Genetic counseling and diagnostic work-up for HNPCC was conducted in families who attended the high risk clinic for inherited cancer. We identified the mutation c.3984_3987dup in the MSH6 gene in 19 members of four unrelated Ashkenazi families. This mutation results in truncation of the transcript and in loss of expression of the MSH6 protein in tumors. Tumor spectrum among carriers included colon, endometrial, gastric, ovarian, urinary, and breast cancer. All but one family qualified for the Bethesda guidelines and none fulfilled the Amsterdam Criteria. Members of one family also co-inherited the c.6174delT mutation in the BRCA2 gene. The c.3984_3987dup in the MSH6 gene is a mutation leading to HNPCC among Ashkenazi Jews. This is most probably a founder mutation. In contrast to the c.1906G>C founder mutation in the MSH2 gene, tumors tend to occur later in life, and none of the families qualified for the Amsterdam criteria. c.3984_3987dup is responsible for 1/6 of the mutations identified among Ashkenazi HNPCC families in our cohort. Both mutations: c.3984_3987dup and c.1906G>C account for 61% of HNPCC Ashkenazi families in this cohort. These findings are of great importance for counseling, diagnosis, management and surveillance for Ashkenazi families with Lynch syndrome.

Mutation spectrum in HNPCC in the Israeli population

Hereditary non-polyposis colon cancer is caused by mutations in DNA mismatch repair genes. The mutation spectrum in the Israeli population is poorly documented except for the c.1906G>C Ashkenazi founder mutation in the hMSH2 gene. To report our experience in HNPCC screening, the mutations detected and the clinical features among a cohort of Israeli patients. Diagnostic work-up was done in a multi-step process guided by clinical and ethnic information. Tumors of suspected patients were tested for microsatellite instability and immunohistochemistry. Based on tumor analyses, we proceeded to mutation screening by DHPLC followed by sequence analysis and multiplex ligase dependent probe amplification. Ashkenazi Jews were first tested for the c.1906G>C founder mutation. Of the 240 families, 24, including Arabs and Jews from different ethnic origins, were tested positive. All tumors that lost expression of mismatch repair proteins also showed microsatellite instability. There was evidence for involvement of hMSH2 (15) hMLH1 (6) and hMSH6 (3) genes. Mutations were identified in 17/24 (71%) patients: 6 Ashkenazi families harbored the c.1906G>C mutation. Eleven other mutations (2 nonsense, 3 splice site and 6 small deletions) were detected. Three of the mutations are novel. No gross deletions or insertions were detected. This is the first report that characterizes the profile of HNPCC in a cohort of patients in Israel. Tumor testing indicated that the 3 main MMR genes are involved, and that mutation spectrum is broad.

Personalized prostate cancer screening among men with high risk genetic predisposition- study protocol for a prospective cohort study

BackgroundProstate cancer screening among the general population is highly debatable. Nevertheless, screening among high-risk groups is appealing. Prior data suggests that men carrying mutations in the BRCA1& 2 genes may be at increased risk of developing prostate cancer. Additionally, they appear to develop prostate cancer at a younger age and with a more aggressive course. However, prior studies did not systematically perform prostate biopsies and thus cannot determine the true prevalence of prostate cancer in this population.MethodsThis will be a prospective diagnostic trial of screening for prostate cancer among men with genetic predisposition. The target population is males (40–70 year old) carrying a BRCA1 and/or BRCA2 germ line mutation. They will be identified via our Genetic counseling unit. All men after signing an informed consent will undergo the following tests: PSA, free to total PSA, MRI of prostate and prostate biopsy. The primary endpoint will be to estimate the prevalence, stage and grade of prostate cancer in this population. Additionally, the study aims to estimate the impact of these germ line mutations on benign prostatic hyperplasia. Furthermore, this study aims to create a bio-bank of tissue, urine and serum of this unique cohort for future investigations. Finally, this study will identify an inception cohort for future interventional studies of primary and secondary prevention.DiscussionThe proposed research is highly translational and focuses not only on the clinical results, but on the future specimens that will be used to advance our understanding of prostate cancer patho-physiology. Most importantly, these high-risk germ-line mutation carriers are ideal candidates for primary and secondary prevention initiatives.Trial registrationClinicalTrials.gov: NCT02053805.

Malignant Abnormalities in Male BRCA Mutation Carriers: Results From a Prospectively Screened Cohort

This study evaluates the use of a comprehensive screening protocol for prostate, breast, colorectal, and pancreatic cancer and skin malignant abnormalities in male BRCA carriers.

Constitutional mismatch repair deficiency and Lynch syndrome among consecutive Arab Bedouins with colorectal cancer in Israel

We assessed the molecular characteristics and the frequency of mutations in mismatch-repair genes among Bedouin patients with colorectal cancer (CRC) in Israel. Bedouin patients with a diagnosis of CRC at a major hospital in the southern part of Israel were deemed eligible for this study. The primary screening method was immunohistochemical staining for mismatch-repair proteins (MLH1, MSH2, MSH6, and PMS2). For subjects with abnormal immunohistochemical staining, we performed microsatellite instability (MSI) analyses, and for tumors with a loss of MLH1 expression we also performed BRAF testing. In MSI high cases we searched further for germline mutations. Of the 24 patients enrolled, four subjects (16.7%) had MSI high tumors: one subject was found to harbor a biallelic PMS2 mutation, one subject had Lynch syndrome (LS) with MSH6 mutation and two subjects had a loss of MLH1/PMS2 proteins/BRAFwild type/normal MLH1 sequence. Ten patients (41.7%) were younger than 50 at the time of diagnosis and none had first degree relatives with CRC. In conclusion, in this cohort of 24 consecutive Arab Bedouins with CRC, one patient was found to harbor a constitutional mismatch repair deficiency, one patient had LS with MSH6 mutation, and two patients had unresolved loss of MLH1/PMS2 proteins/BRAFwild type phenotype.

PD07-10 MALIGNANCIES IN MALE BRCA MUTATION CARRIERS – RESULTS FROM A PROSPECTIVELY SCREENED COHORT OF PATIENTS ENROLLED TO A DEDICATED MALE BRCA CLINIC

estimates for oncologic outcomes in men with high-risk (HR) and very high-risk (VHR) disease to enable patients and providers to make superior clinical decisions. We therefore sought to construct a novel nomogram that predicts biochemical recurrence (BCR) from a contemporary cohort of men with HR and VHR prostate cancer. METHODS: A total of 1,241 men with HR or VHR prostate cancer who underwent radical prostatectomy from 2005 to 2015 were identified from Johns Hopkins (n 1⁄4 620, training cohort) and the Cleveland Clinic (n 1⁄4 621, validation cohort). The primary endpoint was BCR after radical prostatectomy. Cox multivariable regression was performed to model characteristics and outcomes in the training cohort. The AUC of the model in the training cohort was adjusted for optimism by subjecting the model to bootstrapping with 100 resamples. Model accuracy was assessed using the time-dependent area under the receiver operator characteristic curve (AUC) in the validation cohort. RESULTS: A total of 494 men developed BCR, with 245 arising from the training cohort and 249 from the validation cohort. The overall BCR-free probability was 49.0% (95% CI: 45.4%-52.9%) at 5 years. The nomogram for postoperative BCR probability was developed using age, race, PSA, Gleason grade group, clinical stage, and number of cores with Gleason score 8-10 disease [Figure 1]. Model AUC was 0.730 after optimism-adjustment, as compared to 0.700 and 0.654 in the existing Stephenson and Cancer of the Prostate Risk Assessment (CAPRA) nomograms, respectively [Figure 2]. The nomogram demonstrated similar accuracy in the external validation cohort (AUC 1⁄4 0.734). CONCLUSIONS: Accurate and individualized risk assessment for the outcome of BCR is imperative for optimizing clinical decisions and designing clinical trials. We have herein described a novel predictive tool created exclusively from men with HR and VHR prostate cancer demonstrating better discriminative ability than existing nomograms for the prediction of postoperative BCR in this important patient population.

Hereditary Skin Cancer

Skin cancer can be divided into three categories: basal cell carcinoma, squamous cell carcinoma, and melanoma. Because of the heterogeneity of the skin cancer phenotypes as well as the unknown exact correlation to genotypes, genetic testing is not offered on routine bases for all types of skin cancers. Several approaches are being used by clinicians, to determine the possible genetic components, which may be involved after complete skin examination by a dermatologist as a screening tool for skin cancer and family history determination. Molecular genetics of melanoma can be both diagnostically and therapeutically useful. When candidate’s genes are known, according to the skin cancer phenotypes or the syndrome, Sanger sequencing and gene copy number variations (MLPA or RT-PCR) are applied. More recently, the use of comparative genomic hybridization (CGH), analysis of copy number in known miRNA genes, and exome sequencing, followed by screening of targeted genes in melanoma, helps to elucidate the genetic background of several skin cancers and the appropriate therapeutic approach. Referral of individuals affected or at risk for skin cancers to a genetic counselor or hereditary cancer center that routinely tests skin cancers patients is recommended.

Earlier Age of Breast Cancer Onset in Israeli BRCA Carriers-Is it a Real Phenomenon?

Data on genetic anticipation in breast cancer are sparse. We sought to evaluate age at diagnosis of breast cancer in daughters with a BRCA mutation and their mothers. A review of all carriers of the BRCA mutation diagnosed with breast cancer at the Genetics Institute of a tertiary medical center in 2000–2013 yielded 80 women who could be paired with a mother with breast cancer who was either a carrier of the BRCA mutation or an obligate carrier according to pedigree analysis. Age at diagnosis, type of mutation (BRCA1, BRCA2), year of birth, and ethnicity were recorded. Paired t‐test was used to analyze differences in age at cancer diagnosis between groups and subgroups. Mean age at diagnosis of breast cancer was 50.74 years (range 22–88) in the mothers and 43.85 years (range 24–75) in the daughters. The difference was statistically significant (p < 0.001). These findings were consistent regardless of type of BRCA mutation, ethnicity, or mothers year of birth. However, on separate analysis of pairs in which the mother was diagnosed before the age of 50 years, there was no significant difference in mean age at diagnosis between mothers and daughters (~42 years for both). Daughters who carry a BRCA mutation are diagnosed with breast cancer at an earlier age than their carrier mothers, with the exception of pairs in which the mother was diagnosed before the age of 50 years. Future breast‐screening guidelines may need to target specific subpopulations of BRCA mutation carriers.