Western Regional Blog – BC, YK, AB, NWT and Nunavut
Purpose of the study: Estimate reduction in risk of ovarian, fallopian tube or peritoneal cancer in women with a BRCA 1 or BRCA2 mutation after oophorectomy, by age of oophorectomy; to estimate the impact of prophylactic oophorectomy on all-cause mortality and to estimate 5 year survival associated with clinically detected ovarian, occult and peritoneal cancers.
Patients and methods:
Women with BRCA1 and BRCA2 mutation identified from international registry (Canada, US, Austria, France, Italy, Norway or Poland). They completed a questionnaire and were observed until diagnosis of ovca, fallop or peritoneal cancer, death, or date of most recent follow-up.
Avg f/u of 5.6 years, 186 women developed either ovca, fallop or peritoneal cancer. HR for these cancers associated with bilateral oophorectomy was 0.20. For those with no history of cancer, HR for all-cause mortality to age 70 was 0.23.
Preventive oophorectomy was associated with a 80% reduction in risk of ovca, fallop or peritoneal cancers in BRCA1 or BRCA2 carriers and 77% reduction in all- cause mortality. The data support the recommendation for a BRCA1 mutation carrier to undergo oophorectomy at age 35.
Some other notes:
– Key finding –the effect of oophorectomy on all- cause mortality
– Impact of oophorectomy on mortality results in large part from reduction in the incidence of ovarian, tubal and peritoneal cancers – but impt component from reducing breast cancer incidence and mortality
– Of the 46 occult cancers, 18 were classified as primary fallopian tube – supports position that standard of care should include removal of tubes with the ovaries at time of preventive surgery
– Prevalence of ovca, fallop, peritoneal cancers was 1.5% for BRCA1 mutation carriers who underwent oophorectomy under age 40, 3.8% for those 40-49. If a woman with a BRCA1 mutation chooses to delay salpingo-oophorectomy until age 40 it is estimated she will have a 4.0% chance of being diagnosed with ovca, is she chooses to wait until age 50 – probability rises to 14.2%
– Confirm impact of oophorectomy on mortality in this study and report the effect of oophorectomy on all-cause mortality is equally strong for BRCA1 and BRCA2 mutation carriers
– Risks and benefits of oophorectomy should be weighed, including degree of protection against cancer and consequences of induced surgical menopause on health and quality of life
– Risk of ovca and breast cancers has been shown to be reduced by preventive oophorectomy, but optimum age for oophorectomy has not been determined nor impact on morality well studied – until now