Outcome and prognostic factors of unexpected ovarian carcinomas

Background We investigated risk factors influencing the outcome of unexpected ovarian carcinomas. Methods We reviewed the ovarian carcinoma patients treated at atertiary medical institution between 2000 and 2017 and analyze the clinico‐pathological characteristics, treatment strategies, recurrence status, and outcome. Results A total of 112 women (65 primary laparoscopic surgery [LSC] and 47 laparotomic surgery [LAPA]) were included in the analysis. The LSC group had smaller ovarian tumors (10.5 ± 7.3 cm vs. 16.6 ± 8.7 cm, p = 0.031) and higher incidence of subsequent staging surgery (56.9% vs. 25.5%, p = 0.0001) compared to the LAPA group. There were 98/112 (86.6%) of early stages (I/II) diseases. The difference between the recurrent rate (27.7% vs. 31.9%), disease‐free survival (DFS), and overall survival (OS) were not significant among surgical groups. In the multivariate analysis, FIGO stage (stage II hazard ratio [HR] 6.61, p = 0.007; stage III HR 8.40, p = 0.002) was the only prognostic factor for DFS. FIGO stage (stage II HR 20.78, p = 0.0001; stage III HR 7.99, p = 0.017), histological type (mucinous HR 12.49, p = 0.036), and tumor grade (grade 3 HR 35.01, p = 0.003) were independent prognostic factors for OS, while women with latency >28 days from primary to staging surgery had significantly poorer OS (p = 0.008). Women with latency >28 days between primary surgery and adjuvant chemotherapy had similar DFS (p = 0.31) and a trend of poorer OS (p = 0.064). Conclusions The prognosis of unexpected ovarian cancer is independent from the primary surgical procedure and comprehensive staging surgery should be performed at close proximity after the diagnosis of unexpected ovarian malignancy. Unexpected malignant ovarian cancers were occasionally diagnosed after surgery for the initial diagnosis of benign ovarian tumors. The primary surgical procedure is not a prognostic factor for incidental ovarian cancer. Comprehensive staging surgery should be performed as soon as possible after the diagnosis of incidental ovarian malignancy.