Neoadjuvant chemotherapy can improve outcome of colorectal cancer patients with unresectable metastasis

Background: The prognosis for colorectal cancer (CRC) patients with unresectable metastases is dismal. This study compared outcomes of different metastatic treatments. Patients and methods: We collected 653 CRC cases with unresectable metastases including 490 cases receiving primary tumor resection then chemotherapy (surgery group) and 163 patients receiving neoadjuvant chemotherapy then did or did not receive operations (chemotherapy (C/T) group) from 2004 to 2010. The statistical endpoint was overall survival from the date of diagnosis. Results: In the C/T group, 124 (76 %) patients received an operation after 9.0 ± 6.2 months of chemotherapy, including 57 (34.9 %) patients with curative surgery. The C/T group had a higher proportion of T4 lesions (37.4 %) than the surgery group (26.9 %). Survival of the C/T group was longer than that of the surgery group (28.8 ± 8.8 vs. 24.3 ± 7.5 months; p = 0.043). Survival of 57 patients receiving curative surgery was 36.0 ± 6.3 months, which was significantly better than that of the 67 patients receiving palliative resection (25.2 ± 5.6, p < 0.001). In the surgery group, 42 (8.6 %) patients received curative metastasectomy after 8.5 ± 7.1 months of postoperative chemotherapy; survival was 30.8 ± 7.8 months, which was significantly better than that of patients who did not receive metastasectomy (22.4 ± 6.3 months). In multivariate analysis, poor differentiation, lymphovascular invasion, isolated cancer nodules, clinical risk score, and curative surgery were independent prognostic factors of overall patient survival. Conclusions: Neoadjuvant chemotherapy can improve outcome of CRC patients with unresectable metastases.