Gynecologic cancers associated with Lynch syndrome/HNPCC.

Lynch syndrome/hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant inherited cancer susceptibility syndrome caused by a germline mutation in one of the deoxyribonucleic acid (DNA) mismatch repair genes. It is associated with early onset of cancer (age younger than 50 years) and the development of multiple cancer types, particularly colon and endometrial cancer. Women with Lynch syndrome have a 40-60% risk of endometrial cancer, which equals or exceeds their risk of colorectal cancer. In addition, they have a 12% risk of ovarian cancer. Despite limited information on the efficacy of surveillance in reducing endometrial and ovarian cancer risk in women with Lynch syndrome, the current gynecologic cancer screening guidelines include annual endometrial sampling and transvaginal ultrasonography beginning at age 30-35 years. In addition, risk-reducing surgery consisting of prophylactic hysterectomy and bilateral salpingooophorectomy should be offered to women aged 35 years or older who do not wish to preserve their fertility.