The results of gynecologic surveillance in families with hereditary nonpolyposis colorectal cancer

• EC surveillance should only be targeted at MMR mutation carriers starting from the age of 35–40.
• Research into attitudes toward screening is needed to clarify the low attendance at gynecological surveillance in MMR-mutation carriers.

ObjectiveWe aimed to estimate the incidence rate of endometrial cancer (EC) and to evaluate the results of EC-surveillance in hereditary nonpolyposis colorectal cancer (HNPCC) families.MethodsAll at-risk women recommended for EC-surveillance by the HNPCC-register—2959 women (19,334 women years)—were included. Data on EC-surveillance were available for 871 women (6894 women years), who had performed 1945 surveillance visits. The average surveillance period was 7.9 (range 0.1−21.7) years and 46% of the women had had less than 3 years between their visits.ResultsDuring 19,334 women years, 60 women with gynecological malignancies or premalignancies were diagnosed. Thirty-nine women had EC. Of these, 31 were from families with identified MMR gene mutations with the median age at diagnosis of 54 (39–83) years (Incidence Rate, IR = 0.63 per 100 women years) and four women from each Amsterdam (AMS)-positive and AMS-like families (median age 64 (55–73) years, IR = 0.06 and 0.05 per 100 women years, respectively, p < .0001).Among the 871 surveilled women, 13 EC were found: 7/13 cases were diagnosed by surveillance examination—two as prevalent cancers, diagnosed at the first visit—and 6/13 based on symptoms. In addition, five complex atypical hyperplasias and four ovarian cancers (OCs) were diagnosed. All these women were MMR mutation carriers.ConclusionBased on 19,334 women years of EC-surveillance, our analysis provides a thorough estimation of the EC risk in women with an MMR mutation, or suspected of having Lynch syndrome. We conclude that EC surveillance should only be targeted at MMR-mutation carriers.