Consideration of hereditary nonpolyposis colorectal cancer in BRCA mutation-negative familial ovarian cancers.

BACKGROUND: Inherited mutations account for approximately 10% of all epithelial ovarian cancers. Breast cancer (BRCA1 and BRACA2) gene mutations are responsible for up to 85% of inherited breast and/or ovarian cancer. Another condition that has been associated with ovarian cancer is hereditary nonpolyposis colorectal cancer syndrome (HNPCC), which carries a lifetime risk of up to 13% for ovarian cancer. The objective of this study was to determine the incidence of HNPCC-related gene mutations in patients with familial ovarian cancer who previously tested negative for BRCA1 and BRCA2 gene mutations. METHODS: Seventy-seven probands were identified who had familial ovarian cancer and negative BRCA gene mutation testing. Their pedigrees were analyzed for HNPCC syndrome. DNA samples underwent gene sequencing and Southern blot analysis for mutations in the 3 most common HNPCC-associated genes: mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2) with reflex testing for MSH6 if tests for the first 2 genes were negative. RESULTS: None of the probands met Amsterdam criteria for the clinical diagnosis of HNPCC. DNA testing revealed 2 patients (2.6%) with deleterious mutations in the MSH2 gene. An additional 8 patients (10.4%) had substitutions in either the MLH1 gene or the MSH2 gene that were classified as variants of uncertain significance. If Amsterdam criteria were expanded to include ovarian cancer, then 15 of 77 patients (19.5%) would have met these expanded criteria. One deleterious mutation was noted in this group, yielding a mutation incidence of 6.7%. This percentage may be even higher if any of the identified variants of uncertain significance are confirmed to be deleterious. CONCLUSIONS: HNPCC should be considered when evaluating patients with suspected hereditary ovarian cancer who have had negative BRCA mutation testing.

The role of hereditary nonpolyposis colorectal cancer in the management of familial ovarian cancer.

PURPOSE: Familial ovarian cancer is most often associated with hereditary breast and ovarian cancer, implicating mutations in the BRCA1 and BRCA2 genes. Hereditary nonpolyposis colorectal cancer, another common syndrome, is also associated with ovarian cancer and is caused by DNA mismatch repair genes. We sought to identify the role of hereditary nonpolyposis colorectal cancer in women with family histories of ovarian cancer. METHODS: The likelihood of a genetic syndrome in 226 oophorectomized women in the Gilda Radner Familial Ovarian Cancer Registry was determined by pedigree analysis using clinical criteria and by calculating the probability of a mutation in genes responsible for hereditary breast and ovarian cancer and hereditary nonpolyposis colorectal cancer using available risk models. RESULTS: Some 86% had a BRCA gene mutation likelihood of 7.8% or higher, warranting consideration of hereditary breast and ovarian cancer. Of the 32 women below this threshold, 4 (12.5%) had family histories that met criteria for clinical diagnosis of hereditary nonpolyposis colorectal cancer. In addition, 16 women (7%) with a BRCA mutation likelihood greater than 7.8% met clinical criteria for hereditary nonpolyposis colorectal cancer or warranted its inclusion in the differential diagnosis. Among all study respondents, 9% had family histories warranting consideration of hereditary nonpolyposis colorectal cancer. CONCLUSION: Hereditary nonpolyposis colorectal cancer should be considered in the differential diagnosis of women with family histories of ovarian cancer.

Role of prophylactic hysterectomy in patients at high risk for hereditary cancers.

BACKGROUND: Current surgical recommendations for ovarian cancer prophylaxis in women at high risk of developing ovarian cancer include bilateral salpingo-oophorectomy (risk-reducing salpingo-oophorectomy (RRSO)). The role of hysterectomy is unclear. We sought to determine outcomes following prophylactic surgery in high-risk women. METHODS: We surveyed unaffected members of the Gilda Radner Familial Ovarian Cancer Registry who had undergone oophorectomy from 1981 to 2002. Data were collected and analyzed for statistical significance by the Fisher's Exact Test. RESULTS: Two hundred eighty women were surveyed, and 154 (55%) responded; 97% were Caucasian and 14% reported being Jewish. The median age of the respondents was 51 years (range 29-79); median age at oophorectomy was 41 years (range 15-68). Fifty-eight patients (38%) reported a laparoscopic procedure. One hundred five patients (68%) had a simultaneous hysterectomy, and 4 (3%) had a prior hysterectomy. Forty-four patients (29%) underwent BSO only. Of these 44 patients, 40 (91%) did not require a subsequent hysterectomy. Of the 4 who did, 2 were for leiomyomas, one for menorrhagia and the other was unknown. While not statistically significant, of the 3 patients who developed a subsequent gynecologic malignancy, all had undergone a hysterectomy. There was a statistically significant difference in whether or not the uterus was removed as part of the procedure by time period, whereby women treated prior to 1990 had a higher likelihood of having a hysterectomy (P = 0.03). CONCLUSION: The women in our study did not require hysterectomy for prevention of malignancy. We conclude that one should screen for benign gynecological indications for hysterectomy when planning a prophylactic BSO for prevention of ovarian cancer. Other potential risk factors for endometrial cancer, including the role of UPSC in HBOC, remain to be elucidated.