Retrospective analysis of sites of recurrence in stage I epithelial ovarian cancer

OBJECTIVE: The aim of the study is to investigate recurrence of stage I epithelial ovarian cancer. METHODS: Six hundred two patients diagnosed with stage I epithelial ovarian cancer at 4 hospitals between 2000 and 2013 were retrospectively analyzed. Age, surgical procedure, substage, histologic type, adjuvant chemotherapy, recurrence, initial recurrence site (peritoneal dissemination [P], hematogenous recurrence [H], lymphogenous recurrence [L], and others [O]), and frequency of recurrence at each site were investigated retrospectively. RESULTS: Median age was 54 years and median follow-up was 60 months. The stage was IA in 180 cases (30%), IB in 8 (1%), IC1 in 247 (41%), IC2 in 63 (10%), and IC3 in 104 (17%). Systematic lymph node dissection including both pelvic and para-aortic lymph nodes was performed in 224 patients (37%), and 412 patients (68%) received adjuvant chemotherapy. Recurrence occurred in 70 patients (11.6%). The median time to recurrence was 18 months, and the stage was IA in 13 (19%), IB in 1 (1%), IC1 in 24 (34%), IC2 in 9 (13%), and IC3 in 23 (33%) cases. The numbers of recurrence at the P, H, L, and O sites, including overlapping cases, were 49 (70%), 18 (26%), 9 (13%), and 6 (9%), respectively, and recurrence by peritoneal dissemination in the pelvis occurred in 43 cases (61%). CONCLUSION: Recurrence of stage I epithelial ovarian cancer by peritoneal dissemination was frequent, especially in the pelvis. There is a need to elucidate the pathogenesis of peritoneal recurrence and to prepare a treatment strategy to prevent pelvic peritoneal recurrence.