Background: The survival benefit of adjuvant chemotherapy after colorectal cancer (CRC) lung metastasectomy is uncertain.
Methods: We enrolled 221 CRC patients who underwent pulmonary metastasectomy between October 2002 and July 2013, including those with previous liver metastasis that had been curatively resected. Disease-free survival (DFS) and overall survival (OS) were calculated from the day of lung metastasectomy.
Results: Among all patients, 176 (79.6%) received adjuvant chemotherapy after lung metastasectomy. Median follow-up was 34.7 months from the time of lung metastasectomy [95% confidence interval (95% CI), 7.4-90.9 months]. Patients treated with adjuvant chemotherapy had longer DFS compared with surgery alone (median 32.7 vs 11.2 months respectively, P = 0.076). Multivariate analysis revealed previous liver metastasis, preoperative carcinoembryonic antigen ≥5 ng/mL, disease-free interval <24 months, and surgery without adjuvant chemotherapy as independent risk factors for recurrence. Low-risk patients who had 0-1 risk factors received a significant survival benefit from adjuvant chemotherapy [hazard ratio (HR) 0.54; 95% CI 0.32-0.91, P = 0.020]; however, high-risk patients with ≥2 risk factors did not (HR 1.02; 95% CI 0.48-2.14, P = 0.964). Patients treated with adjuvant chemotherapy showed no OS benefit compared with patients who received surgery alone (median 89.6 vs 86.8 months respectively, P = 0.833).
Conclusions: CRC patients received lung metastasectomy could have a DFS benefit from adjuvant chemotherapy, especially in low-risk patients. Larger, prospective studies are needed to evaluate the role of adjuvant chemotherapy after CRC lung metastasectomy.