Clinicopathologic characteristics of endometrial cancer in lynch syndrome A French multicenter study

Background: Limited data exist on Lynch syndrome (LS)Yrelated endometrial cancer (EC) features. Amsterdam criteria II, commonly used, have poor sensitivity for detection of LS, which is underdiagnosed. Aim: The aimof this studywas to describe the clinical and pathological features of LS-related EC among mutation-proven patients. Methods: We conducted a retrospective study from1977 to 2013 in 5 hospitals.The inclusion criteria were patients who had a primary EC associated to LS proven by a germline mutation. We analyzed the clinical data and the pathology of the tumors. The patient management and the survival data were also collected. Results: Forty-nine patients (15 MLH1, 20 MSH2, 13 MSH6, 1 PMS2) were included. The mean age at diagnosiswas 49.7 (SD, 10.5) years. Themedian bodymass indexwas 22.6 kg/m2. In 81.4% of cases, EC was the first cancer of the LS spectrum to occur. Endometrioid adenocarcinoma accounted for 89.2% of the EC, the lower uterine segment was involved in 25% of cases, and a synchronous ovarian cancerwas present in 21.6% of patients. The tumors were grade 3 in 19.3% of cases and FIGO (International Federation of Gynecology and Obstetrics) stage I in 66.6% of cases.With a median follow-up of 58 months, 3 patients with conservative management developed a recurrence, and no patient died of EC. Conclusions: The LS-associated EC is characterized by a young age at onset, a high prevalence of lower uterine segment involvement, and synchronous ovarian cancers. The prognosis of these cancers does not appear different from sporadic tumors.