Prognosis of stage I ovarian mucinous tumors according to expansile and infiltrative types

Objective: Mucinous ovarian carcinomas account for 3% of all epithelial ovarian carcinomas and are categorized into expansile or infiltrative subtypes. Nevertheless, the prognostic impact of these subtypes in stage I disease remains unclear. Methods: This retrospective study included patients with mucinous ovarian cancer who were referred to or treated at our institution between 1976 and 2022. Pathologic review was performed by 2 expert pathologists. Only patients with stage I disease were included in this study. Tumors were characterized as expansile or infiltrative, and oncologic features were analyzed. Results: A total of 80 cases met the inclusion criteria, with 36 and 44 patients having expansile and infiltrative subtypes, respectively. The disease stages were as follows: expansile subtype in 14 patients, stage IC in 22 patients, infiltrative subtype stage IA in 26 patients, and stage IC in 18 patients. The characteristics of the 2 groups of patients were comparable, except for the use of lymphadenectomy (more frequent in the infiltrative subtype: 28/44 [63%] vs 8/36 [22%] in expansile disease, p < .05). After a median follow-up of 79 months (range; 27.7-119.2), 10 (12.5%) recurrences occurred (3 expansile and 7 infiltrative). A total of 2 cases of expansile recurrence with pelvic recurrence were cured after secondary surgery and chemotherapy, and 1 patient died of the disease. A total of 5 patients with infiltrative recurrence had extra-pelvic spread and died of the disease, 1 patient was still alive with progressive disease, and the last was still alive and disease-free. A total of 2 cases of recurrence were observed after conservative surgery (1 of each subtype). Conclusions: In this series, the overall and disease-free survival rates were not significantly different between patients with expansile and infiltrative stage I mucinous ovarian carcinoma. However, the prognosis of recurrent infiltrative cases is poorer than expansile cases.