Johan J. P. Gille

Frequency and Spectrum of Cancers in the Peutz-Jeghers Syndrome

Background: Although an increased cancer risk in Peutz-Jeghers syndrome is established, data on the spectrum of tumors associated with the disease and the influence of germ-line STK11/LKB1 (serine/threonine kinase) mutation status are limited. Experimental Design: We analyzed the incidence of cancer in 419 individuals with Peutz-Jeghers syndrome, and 297 had documented STK11/LKB1 mutations. Results: Ninety-six cancers were found among individuals with Peutz-Jeghers syndrome. The risk for developing cancer at ages 20, 30, 40, 50, 60, and 70 years was 2%, 5%, 17%, 31%, 60%, and 85%, respectively. The most common cancers represented in this analysis were gastrointestinal in origin, gastroesophageal, small bowel, colorectal, and pancreatic, and the risk for these cancers at ages 30, 40, 50, and 60 years was 1%, 9%, 15%, and 33%, respectively. In women with Peutz-Jeghers syndrome, the risk of breast cancer was substantially increased, being 8% and 31% at ages 40 and 60 years, respectively. Kaplan-Meier analysis showed that cancer risks were similar in Peutz-Jeghers syndrome patients with identified STK11/LKB1 mutations and those with no detectable mutation (log-rank test of difference χ2 = 0.62; 1 df; P = 0.43). Furthermore, the type or site of STK11/LKB1 mutation did not significantly influence cancer risk. Conclusions: The results from our study provide quantitative information on the spectrum of cancers and risks of specific cancer types associated with Peutz-Jeghers syndrome.

Dysplastic changes in prophylactically removed Fallopian tubes of women predisposed to developing ovarian cancer

The aim of this study was to investigate the occurrence of (pre)neoplastic lesions in overtly normal Fallopian tubes from women predisposed to developing ovarian carcinoma. The presence of (pre)neoplastic lesions was scored in histological specimens from 12 women with a genetically determined predisposition for ovarian cancer, of whom seven tested positive for a germline BRCA1 mutation. A control group included 13 women. Immunohistochemistry was used to determine the expression of p21, p27, p53, cyclin A, cyclin D1, bcl‐2, Ki67, HER‐2/neu, and the oestrogen and progesterone receptors. Loss of heterozygosity (LOH) analysis on the BRCA1 locus was also assessed on dysplastic tissue by PCR studies. Of the 12 women with a predisposition for ovarian cancer, six showed dysplasia, including one case of severe dysplasia. Five harboured hyperplastic lesions and in one woman no histological aberrations were found in the Fallopian tube. No hyperplastic, dysplastic or neoplastic lesions were detected in the Fallopian tubes of control subjects. In the cases studied, morphologically normal tubal epithelium contained a higher proportion of Ki67‐expressing cells (p=0.005) and lower fractions of cells expressing p21 (p<0.0001) and p27 (p=0.006) than in the control group. Even higher fractions of proliferating cells were found in dysplastic areas (p=0.07) and accumulation of p53 was observed in the severely dysplastic lesion. Expression patterns of other proteins studied, including the hormone receptors, were similar in cases and controls. One subject, a germline BRCA1 mutation carrier, showed loss of the wild‐type BRCA1 allele in the severely dysplastic lesion. In conclusion, the Fallopian tubes of women predisposed to developing ovarian cancer frequently harbour dysplastic changes, accompanied by changes in cell‐cycle and apoptosis‐related proteins, indicating an increased risk of developing tubal cancer. Copyright

Genomic deletions of MSH2 and MLH1 in colorectal cancer families detected by a novel mutation detection approach

Hereditary non-polyposis colorectal cancer is an autosomal dominant condition due to germline mutations in DNA-mismatch-repair genes, in particular MLH1, MSH2 and MSH6. Here we describe the application of a novel technique for the detection of genomic deletions in MLH1 and MSH2. This method, called multiplex ligation-dependent probe amplification, is a quantitative multiplex PCR approach to determine the relative copy number of each MLH1 and MSH2 exon. Mutation screening of genes was performed in 126 colorectal cancer families selected on the basis of clinical criteria and in addition, for a subset of families, the presence of microsatellite instability (MSI-high) in tumours. Thirty-eight germline mutations were detected in 37 (29.4%) of these kindreds, 31 of which have a predicted pathogenic effect. Among families with MSI-high tumours 65.7% harboured germline gene defects. Genomic deletions accounted for 54.8% of the pathogenic mutations. A complete deletion of the MLH1 gene was detected in two families. The multiplex ligation-dependent probe amplification approach is a rapid method for the detection of genomic deletions in MLH1 and MSH2. In addition, it reveals alterations that might escape detection using conventional diagnostic techniques. Multiplex ligation-dependent probe amplification might be considered as an early step in the molecular diagnosis of hereditary non-polyposis colorectal cancer.

Recurrence and variability of germline EPCAM deletions in Lynch syndrome

Recently, we identified 3′ end deletions in the EPCAM gene as a novel cause of Lynch syndrome. These truncating EPCAM deletions cause allele‐specific epigenetic silencing of the neighboring DNA mismatch repair gene MSH2 in tissues expressing EPCAM. Here we screened a cohort of unexplained Lynch‐like families for the presence of EPCAM deletions. We identified 27 novel independent MSH2‐deficient families from multiple geographical origins with varying deletions all encompassing the 3′ end of EPCAM, but leaving the MSH2 gene intact. Within The Netherlands and Germany, EPCAM deletions appeared to represent at least 2.8% and 1.1% of the confirmed Lynch syndrome families, respectively. MSH2 promoter methylation was observed in epithelial tissues of all deletion carriers tested, thus confirming silencing of MSH2 as the causative defect. In a total of 45 families, 19 different deletions were found, all including the last two exons and the transcription termination signal of EPCAM. All deletions appeared to originate from Alu‐repeat mediated recombination events. In 17 cases regions of microhomology around the breakpoints were found, suggesting nonallelic homologous recombination as the most likely mechanism. We conclude that 3′ end EPCAM deletions are a recurrent cause of Lynch syndrome, which should be implemented in routine Lynch syndrome diagnostics. Hum Mutat 32:1–8, 2011.

A homozygous MSH6 mutation in a child with café-au-lait spots, oligodendroglioma and rectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant condition due to heterozygous germline mutations in DNA mismatch repair genes, in particular MLH1, MSH2 and MSH6. Recently, a syndrome was recognized in which children develop haematological malignancies, solid tumours and signs of neurofibromatosis type 1 due to bi-allelic MMR gene mutations in MLH1, MSH2 and PMS2. Here we describe the child of healthy consanguineous parents who had café-au-lait spots, oligodendroglioma, and rectal cancer. The patient was homozygous for the MSH6 mutation c.3386_3388delGTG in exon 5 which has a predicted pathogenic effect. Germline NF1 gene mutation testing was negative. The rectal tumour showed microsatellite instability and absence of MSH6 staining, whereas the brain tumour was MSI stable and showed normal immunohistochemical expression of MSH6. Apparently, not only MLH1, MSH2 and PMS2, but also MSH6 is involved in the syndrome of childhood cancer and signs of neurofibromatosis type 1.

Distinction between hereditary and sporadic breast cancer on the basis of clinicopathological data.

Background: About 5% of all breast cancer cases are attributable to germline mutations in BRCA1 or BRCA2 genes. BRCA mutations in suspected carriers, however, may be missed, which hampers genetic counselling. Materials and methods: Different clinicopathological features were compared between 22 breast cancers from carriers of proved BRCA1 mutations and 604 cancers from sporadic controls. In addition, 5 BRCA2-related breast cancers and 66 breast cancers of untested patients at intermediate risk and 19 breast cancers of untested patients at high risk of hereditary disease on the basis of family history were evaluated. Results: A “probably sporadic” class (age ⩾54 years and epidermal growth factor receptor (EGFR) negative; 68% of cases) with a 0% chance of BRCA1-related breast cancer containing 79% of the sporadic cases was yielded by using a decision tree with age, Ki67 and EGFR. A 75% chance of BRCA1-related breast cancer was shown by the “probably BRCA1-related” class (age <54 years and Ki67 ⩾25%; 8% of cases) with 82% of the BRCA1-related cases but only 1.4% of the sporadic cases. Most cases at intermediate or high risk of hereditary disease on the basis of family history could be classified with high probability as either probably BRCA1 related or probably sporadic. Conclusion: Breast carcinomas can be classified with a high level of certainty as sporadic or related to BRCA1 germline mutations by using a decision tree with age, Ki67 and EGFR. This can be clinically useful in mutation analysis in families with a borderline risk of hereditary disease.

Renal cancer and pneumothorax risk in Birt-Hogg-Dubé syndrome; an analysis of 115 FLCN mutation carriers from 35 BHD families.

Background:Birt–Hogg–Dubé (BHD) syndrome is an autosomal dominant condition caused by germline FLCN mutations, and characterised by fibrofolliculomas, pneumothorax and renal cancer. The renal cancer risk, cancer phenotype and pneumothorax risk of BHD have not yet been fully clarified. The main focus of this study was to assess the risk of renal cancer, the histological subtypes of renal tumours and the pneumothorax risk in BHD.Methods:In this study we present the clinical data of 115 FLCN mutation carriers from 35 BHD families.Results:Among 14 FLCN mutation carriers who developed renal cancer 7 were <50 years at onset and/or had multifocal/bilateral tumours. Five symptomatic patients developed metastatic disease. Two early-stage cases were diagnosed by surveillance. The majority of tumours showed characteristics of both eosinophilic variants of clear cell and chromophobe carcinoma. The estimated penetrance for renal cancer and pneumothorax was 16% (95% minimal confidence interval: 6–26%) and 29% (95% minimal confidence interval: 9–49%) at 70 years of age, respectively. The most frequent diagnosis in families without identified FLCN mutations was familial multiple discoid fibromas.Conclusion:We confirmed a high yield of FLCN mutations in clinically defined BHD families, we found a substantially increased lifetime risk of renal cancer of 16% for FLCN mutation carriers. The tumours were metastatic in 5 out of 14 patients and tumour histology was not specific for BHD. We found a pneumothorax risk of 29%. We discuss the implications of our findings for diagnosis and management of BHD.

A New Locus-Specific Database (LSDB) for Mutations in the Folliculin (FLCN) Gene

Birt‐Hogg‐Dubé syndrome (BHD) is an autosomal dominant condition characterised by the presence of facial fibrofolliculomas, pulmonary cysts which may be associated with spontaneous pneumothorax and renal tumours. Germline mutations in the gene Folliculin (FLCN) were first identified in BHD patients in 2002. In addition FLCN mutations have also been described in families with isolated primary spontaneous pneumothorax (PSP) and also familial clear cell renal carcinomas (FcRCC). We have established a locus‐specific database based on the Leiden Open (source) Variation Database (LOVD) software. The version of the database contains 60 previously published mutations and 10 previously unpublished novel germline FLCN mutations. The mutations are comprised of deletions (44.3%), substitutions (35.7%), duplications (14.3%) and deletion/insertions (5.7%). The database is accessible online at http://www.lovd.nl/flcn.

Histopathological characteristics of BRCA1- and BRCA2-associated intraperitoneal cancer: a clinic-based study

The aim of the research was to assess possible histopathological differences between BRCA1- and BRCA2-associated malignant intraperitoneal (ovarian/fallopian tube/peritoneal) tumors and their sporadic counterparts. Dutch families harboring pathogenic BRCA1 or BRCA2 mutations were selected. Included were patients who had had malignant primary ovarian, fallopian tube or peritoneal tumors. Histopathological data was compared with data obtained from the Dutch cancer registry between 1989 and 1993 (reference group). A total of 63 with primary intraperitoneal malignant tumors were identified in 41 families. Non-epithelial malignant tumors were not observed in the study group versus 6% (n = 404) in the reference group (n = 6,789, P = 0.04). These tumors were excluded from further analysis, as were ovarian adenocarcinomas not otherwise specified, since these were detected in 22% of the study group, and in 19% of the reference group (P = 0.76). Serous carcinomas were detected in 94% (47/50) of the women in the study group in contrast to 62% (3,145/5,088) of the reference group (P < 0.01). In the study group, mucinous and endometrioid ovarian adenocarcinomas and serous ovarian borderline tumors each comprised 2.0% of the tumors. Clear cell ovarian carcinomas were not detected. In contrast, these percentages were 16% (P < 0.01), 10% (P = 0.07), 7% (P = 0.16) and 5% (P = 0.12), respectively, in the reference group. In the study group, 6.0% of the carcinomas arose in the fallopian tube versus 1.9% in the reference group (P = 0.03). Four percent of the study group developed primary serous peritoneal carcinomas, versus six percent in the reference group (P = 0.57). Serous carcinoma is the predominant type of intraperitoneal malignancy occurring in women harboring BRCA1 or BRCA2 mutations. Non-epithelial cancer does not seem to be part of the tumor spectrum of BRCA mutation carriers. This suggests, therefore, that serous tumors may be the only subtype related to a BRCA1 or BRCA2 mutation. Furthermore, fallopian tube carcinoma occurred more often in BRCA mutation carriers than in the reference population.

Participation in preconceptional carrier couple screening: characteristics, attitudes, and knowledge of both partners

Editor—Couples in which both partners are carriers for a particular autosomal recessive disease, such as cystic fibrosis, Tay-Sachs disease, or thalassaemia, have a 1 in 4 risk for each child to have this disorder. Population carrier screening programmes aimed at the identification of carrier couples make it possible to inform these couples about their risk and about the reproductive options that are available. Before beginning any genetic screening programme, it is important to assess community interest in screening.1 It is well known that the way in which carrier screening is offered and the timing, for example, during or outside pregnancy, determine participation in screening and the reasons for participation. Screening offered face to face with the possibility of immediate testing gives high uptake rates, whereas offers made by mailed invitation or poster announcements attract little interest.2-6 Most of the data on motives for participation have been obtained from programmes offering carrier screening during pregnancy.7-15 In these studies, a high interest in screening was reported, although it has been argued that testing during pregnancy is often accepted just because it is offered.16The decision to participate was mostly made by women, who were often initially tested without discussing it with their partner. Anxiety has been reported among those who are tested positive, while waiting for their partners results.10 17 18 It can also cause distress when the partner is not available or does not want to be tested.19 Furthermore, prenatal screening leaves limited reproductive options for a carrier couple and might impose time constraints when decisions about a prenatal diagnosis have to be made.20 Offering carrier screening outside pregnancy shows low participation rates when no pregnancy is planned, but interest is higher when there are plans for having children (preconceptional).4 7 …