Impact of Ovarian Metastatectomy on Survival Outcome of Colorectal Cancer Patients with Ovarian Metastasis: A Retrospective Study

BACKGROUND: Ovarian metastasis from colorectal cancer (CRC) is rare and lacks standard treatment. The benefit of metastatectomy remains to be elucidated. This study was conducted to assess the impact of metastatectomy on survival outcome and explore prognostic factors in ovarian metastatic CRC patients. METHODS: Information of ovarian metastatic CRC patients between January 2008 and December 2017 were collected retrospectively from database of West China Hospital, Sichuan University. Kaplan–Meier method was used to estimate disease-specific survival (DSS) after diagnosis of ovarian metastasis, and multivariate Cox regression analysis was applied to identify prognostic factors. RESULTS: Totally, 68 female patients from a cohort of 2170 cases were eligible. The median age at diagnosis was 46.5 years. The median DSS was 25.0 months (95% confidence interval (CI): 21.0–29.0 months). Kaplan–Meier analysis and Log rank test showed that complete resection of ovarian metastases (median DSS: 33.0 months) could significantly prolong patients’ survival time, compared with palliative and no resection (median DSS: 20.0 months and 22.0 months, respectively), regardless of systemic chemotherapy (P<0.05). Multivariate analysis demonstrated regional lymph nodes metastasis of primary tumor (hazard ratio (HR): 3.438, 95% CI: 1.094–10.810, P=0.035), primary tumor resection (HR: 6.436, 95% CI: 1.770–23.399, P=0.005), differentiation grade (HR: 0.272, 95% CI: 0.107–0.693, P=0.006), complete resection of ovarian metastases (vs palliative resection: HR: 17.091, 95% CI: 3.040–96.099, P=0.001; vs no resection: HR: 9.519, 95% CI: 1.581–57.320, P=0.014), and systemic chemotherapy (HR: 3.059, 95% CI: 1.089–8.595 P=0.034) were independent prognostic factors. CONCLUSION: Complete resection of ovarian metastases could independently predict favorable survival in ovarian metastatic CRC, while palliative resection could not improve patients’ prognosis compared with no resection.