Women with a germline mutation in one of the MMR-genes MLH1, MSH2 or MSH6 reportedly have 4-12% lifetime risk of ovarian cancer, but there is limited knowledge on survival. Prophylactic bilateral salpingo-oophorectomy (PBSO) has been suggested for prophylaxis.
The purpose of this retrospective multicentre study was to describe survival in carriers of pathogenic mutations in one of the MMR-genes, and who had contracted ovarian cancer.
Women who had ovarian cancer, and who tested positive for or were obligate carriers of an MMR-mutation, were included from eleven European centres for hereditary cancer. Most women had not attended for gynaecological screening. Crude and disease-specific survival was calculated by the Kaplan-Meier algorithm.
Among the 144 women included, 81.5% had FIGO stage 1 or 2 at diagnosis. Ten-year ovarian cancer specific survival independent of staging was 80.6%, compared to less than 40% that is reported both in population based series and in BRCA-mutation carriers. Disease specific 30 years survival for ovarian cancer was 71.5%, and for all HNPCC/Lynch syndrome related cancers including ovarian cancer 47.3%.
In the series examined, infiltrating ovarian cancer in Lynch syndrome had a better prognosis than infiltrating ovarian cancer in BRCA1/2 mutation carriers or in the general population. Lifetime risk of ovarian cancer of about 10% and a risk of dying of ovarian cancer of 20% gave a lifetime risk of dying of ovarian cancer of about 2% in female MMR-mutation carriers.