Autosomal dominantly inherited tumor-prone syndromes are a substantial health problem and are amenable to epidemiologic studies by combining cancer surveillance registries with a genetic register (GR)-based approach. Knowledge of the frequency of the conditions provides a basis for appropriate health-resources allocations. GRs for five tumor-prone syndromes were established in the Manchester region of North West England in 1989 and 1990. Mapping birth dates of affected individuals from families onto regional birth rates has allowed an estimate of birth incidence, disease prevalence, and de novo mutation rates. Disease prevalence in order of frequency were for neurofibromatosis type 1 (NF1): 1 in 4,560; familial adenomatous polyposis (FAP): 1 in 18,976; nevoid basal cell carcinoma [Gorlin syndrome (GS)]: 1 in 30,827; neurofibromatosis type 2 (NF2) 1 in 56,161; and von Hippel Lindau (VHL) 1 in 91,111. Best estimates for birth incidence were: 1 in 2,699; 1 in 8,619; 1 in 14,963, 1 in 33,000; and 1 in 42,987, respectively. The proportions due to de novo mutation were: 42% (NF1); 16% (FAP); 26% (GS); 56% (NF2); and 21% (VHL). Estimates for NF1, NF2, FAP, and VHL are in line with previous estimates, and we provide the first estimates of birth incidence and de novo mutation rate for GS.

Lynch syndrome or hereditary non-polyposis colorectal cancer is caused by mutations of DNA mismatch repair (MMR) genes. The extracolonic tumour spectrum includes endometrial, ovarian, gastric, small bowel, pancreatic, hepatobiliary, brain, and urothelial neoplasms. Families were referred on the basis of clinical criteria. Tumour immunohistochemistry and microsatellite testing were performed. Appropriate patients underwent sequencing of relevant exons of the MMR genes. Proven and obligate mutation carriers and first-degree relatives (FDRs) with a Lynch syndrome spectrum cancer were considered mutation carriers, as were a proportion of untested, unaffected FDRs based on the proportion of unaffected relatives testing positive in each age group. Kaplan-Meier analysis of risk to 70 years was calculated. One hundred and eighty-four Lynch syndrome spectrum extracolonic cancers in 839 proven, obligate, or assumed mutation carriers were analysed. Cumulative risk for females of an extracolonic tumour is 47.4% (95% CI 43.9-50.8). The risk to males is 26.5% (95% CI 22.6-30.4). There was no reduction in gynaecological malignancies due to gynaecological screening (examination, transvaginal ultrasound scan, hysteroscopy and endometrial biopsy). Males have a higher risk of gastric cancer than females (p = 0.0003). Gastric cancer risk in those born after 1935 does not justify surveillance. These penetrance estimates have been corrected for ascertainment bias and are appropriate for those referred to a high-risk clinic.

Purpose: The uptake of risk-reducing surgery in women at increased risk of breast and ovarian cancer is highly variable between countries and centers within countries. We have investigated the rate, timing, and age of uptake of surgery in the northwest of England to report the results after up to 7 years in a Regional Genetics center. Methods: Uptake was documented in 211 known unaffected BRCA1/2 mutation carriers from 509 families and in 3,515 women at >25% lifetime risk of breast cancer without known mutations. Results: Of the 211 mutation carriers, 40% opted for bilateral risk-reducing mastectomy (BRRM) and 45% underwent bilateral risk-reducing salpingo-oophorectomy (BRRSPO). Uptake of BRRM was significantly related to lifetime risk and age but continued over several years. In women not known to carry a BRCA mutation, 6.4% of women at 40% to 45% lifetime risk, 2.5% of women at 33% to 39% lifetime risk, and 1.8% of women at 25% to 32% lifetime risk underwent BRRM (P < 0.005). BRRSPO uptake was greater in BRCA1 (52%) than BRCA2 (28%) carriers but in both groups tended to occur within the first 2 years after gene test (except in the youngest age group) and in women between the ages of 35 and 45. Conclusion: To truly assess the uptake of risk-reducing surgery, longer-term follow-up is necessary particularly in younger women who are likely to delay BRRSPO. Careful risk counseling does seem to influence women's decisions for surgery, although the effect is not immediate. (Cancer Epidemiol Biomarkers Prev 2009;18(8): 2318-24)