Decision-making in postoperative chemotherapy for ovarian metastasis from colorectal cancer: a retrospective single-center study

BACKGROUND: Ovarian metastases from colorectal cancer are relatively uncommon, and no consensus has been reached regarding resection of metastases or chemotherapy before and after surgery. We evaluated the clinicopathological characteristics of ovarian metastases from colorectal cancer and the impact of metastatic resection. We also performed a comparative analysis to clarify the prognostic impact of metastatic resection and the choice of chemotherapy before and after surgery. METHODS: Between 2006 and 2014, 38 patients at our institution underwent resection of ovarian metastases from colorectal cancer. Clinicopathological data were extracted from the patients’ records and evaluated with respect to the long-term outcome. For 15 patients with metachronous ovarian metastases who received chemotherapy until immediately before resection, we compared the prognosis with and without changes in the regimen after resection. RESULTS: The 5-year overall survival rate was 19.9%, and the median survival duration was 27.2 months. The survival rate in the R0 resection group (n = 8) was significantly better than that in the R1/2 resection group (n = 30) (P = 0.0004). Patients without peritoneal dissemination (n = 15) or extra-ovarian metastases (n = 31) had a significantly better prognosis than those with peritoneal dissemination (n = 23) or extra-ovarian metastases (n = 7) (P = 0.040 and P = 0.0005, respectively). The progression-free survival and median survival times of patients who resumed chemotherapy after resection without a change in their preoperative regimen were 10.2 months and 26.2 months, respectively, while those among patients with a change in their regimen before resection versus after resection were 11.0 months and 18.1 months, respectively. The difference between the two groups was not statistically significant (progression-free survival time and median survival time: P = 0.52 and P = 0.48, respectively). CONCLUSIONS: Patients who underwent R0 resection of ovarian metastases clearly had a better prognosis than those who underwent R1/2 resection. Additionally, a poor prognosis was associated with the presence of peritoneal dissemination and extra-ovarian metastases. The data also suggested that resumption of chemotherapy without changing the regimen after resection could preserve the next line of chemotherapy for future treatment and improve the prognosis.