Role of resection for extrahepatopulmonary metastases of colon cancer

Background Although surgical resection for liver or lung metastases of colorectal cancer has been widely accepted, the use of this approach for extrahepatopulmonary metastases remains debatable due to the systemic nature of the disease. The aim of this study was to clarify the utility of resection along with perioperative chemotherapy for patients with extrahepatopulmonary metastases of colon cancer. Methods This is a retrospective single-arm study at a single institution. Forty-two patients with resectable extrahepatopulmonary metastases who underwent metastasectomy with curative intent between 2009 and 2018 at Nagoya University Hospital were retrospectively analyzed. The primary outcomes measured were overall and relapse-free survival. Results The most common metastatic site was the peritoneum (n = 31), followed by the distant lymph nodes (n = 10), ovary (n = 1) and spleen (n = 1), with overlaps. Preoperative and postoperative chemotherapies were administered to 22 and 8 patients, respectively; the remaining 14 patients received surgery alone. R0 resection was achieved in 36 patients (85.7%). The 5-year overall survival and 3-year relapse-free survival rates were 58.6% and 33.8%, respectively. In the univariate analysis, R1 resection was associated with a poor relapse-free survival rate (P = 0.02). In the multivariate analysis, the absence of perioperative chemotherapy was an independent risk factor for poor overall survival rates (P = 0.02). Conclusions Surgical resection benefited selected patients with extrahepatopulmonary metastases with favorable long-term survival outcomes. Surgery alone without systemic chemotherapy is likely to bring poor outcome; therefore, preoperative induction might be promising to keep up with chemotherapy. This study aimed to clarify the utility of metastasectomy of extrahepatopulmonary metastases from colon cancer. Metastasectomy benefited selected patients especially when perioperative chemotherapy was given.