Showing papers by "Fred H. Menko published in 2002"

Surveillance for hereditary nonpolyposis colorectal cancer: a long-term study on 114 families.

Abstract: PURPOSE: Hereditary nonpolyposis colorectal cancer is caused by germline mutations in DNA mismatch repair genes. Mutation carriers have a 60 to 85 percent risk of developing colorectal cancer. In the Netherlands hereditary nonpolyposis colorectal cancer families are monitored in an intensive surveillance program. The aim of this study was to examine the stage of the screening-detected tumors in relation to the surveillance interval and to assess the risk of developing colorectal cancer while on the program. METHODS: The Dutch hereditary nonpolyposis colorectal cancer family registry was used. A total of 114 families had a mismatch repair gene defect and/or met the clinical criteria for hereditary nonpolyposis colorectal cancer. The interval between surveillance and colorectal cancer was investigated in initially healthy family members who underwent at least one surveillance examination without showing evidence for colorectal cancer (surveillance group) and in family members who previously underwent partial or subtotal colectomy for colorectal cancer. The risk of colorectal cancer was calculated for proven mutation carriers (surveillance group) and for putative carriers after partial or subtotal colectomy. RESULTS: A total of 35 cancers were detected while on the program. With intervals between colorectal cancer and the preceding surveillance examination of two years or less, tumors were at Dukes Stage A (n = 4), B (n = 11), and C (1). With intervals of more than two years, tumors were at Dukes Stage A (n = 3), B (n = 10), and C (n = 6). The 10-year cumulative risk of developing colorectal cancer was 10.5 (95 percent confidence interval, 3.8-17.2) percent in proven mutation carriers, 15.7 (95 percent confidence interval, 4.1-27.3) percent after partial colectomy, and 3.4 percent after subtotal colectomy. CONCLUSION: There is a substantial risk of developing colorectal cancer while on the program. However, all tumors but one of subjects who underwent a surveillance examination two years or less before detection were at a local stage. We recommend surveillance for hereditary nonpolyposis colorectal cancer with an interval of two years or less.

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

Abstract: 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.

Histopathologic features of genetically determined ovarian cancer.

Abstract: Inheritance of germline mutations of BRCA1 or BRCA2 genes account for approximately 10% of ovarian carcinomas, but the characterization of these genetically determined cancers is incomplete. The objective of our study was to characterize the histologic features of ovarian carcinomas associated with germline mutations of BRCA1 and BRCA2. Thirty-two ovarian carcinomas associated with germline BRCA1 or BRCA2 mutations and 40 ovarian carcinomas from patients screened as negative for germline mutations were obtained from three centers. A gynecologic pathologist, blinded to mutation status, reviewed each case, with documentation of the histologic type, Gynecologic Oncology Group (GOG) grade, architectural and nuclear grade, Silverberg grade, and mitotic activity. All BRCA1 and BRCA2 mutation-associated cases were invasive serous carcinomas, and of these 50% were GOG grade 3, 41% had an architectural grade of 3 (predominant solid architecture), 84% a nuclear grade of 3, 72% a mitotic score of 3 (>25 mitoses per 10 HPF), and 75% a Silverberg grade of 3. The differences in histologic type (p = 0.001) and Silverberg grade (p = 0.002) between these tumors and the control group were statistically significant and remained so when comparisons between BRCA carriers and noncarriers were restricted to carcinomas of serous histology alone. Ovarian carcinomas associated with germline mutations of BRCA1/BRCA2 are, in this study, invasive serous carcinomas, with a statistically significant higher histologic grade than ovarian carcinomas without BRCA mutations when using the recently proposed Silverberg grading system.

Atypical MEN type 2B associated with two germline RET mutations on the same allele not involving codon 918.

Abstract: A kindred was diagnosed with atypical MEN type 2B characterized by medullary thyroid cancer and mucosal neurilemmomas in multiple family members. Mutation analysis revealed a double RET germline mutation, Val804Met and Ser904Cys, in affected individuals. The clinical phenotype, the functional effect of the mutations, and the clinical implications of our findings are discussed.

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

Abstract: 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 cafe-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.

Recommendations for the management of women with an increased genetic risk of gynaecological cancer

Abstract: About 5% of all ovarian-cancer cases are caused by a genetic predisposition, in particular as a component of the autosomal dominant hereditary breast-ovarian-cancer syndrome. This syndrome is usually due to germline mutations in the BRCA1- or BRCA2-gene. Ovarian and endometrial cancer also occur in families with hereditary non-polyposis colorectal cancer (HNPCC). This syndrome is caused by germline mutations in DNA mismatch-repair genes. Women at high risk of gynaecological cancer based upon familial clustering of disease or a demonstrated pathogenic germ-line mutation are candidates for surveillance: annual gynaecological examinations, including vaginal echoscopy and serum carcinoma antigen CA125 testing. Prophylactic surgery in the form of adnexectomy leads to a marked, but not complete, reduction of ovarian-cancer risk in high-risk cases. There is insufficient evidence to advise against the use of oral contraceptives or hormonal substitution after adnexectomy for healthy women with a genetic predisposition to breast cancer. Recommendations for surveillance and prevention should only be given after genetic-risk counselling, based on a detailed family study and DNA-based diagnosis.