Early Serum Carcinoembryonic Antigen Reduction Predicts Tumor Shrinkage and Overall Survival in Colorectal Cancer Patients with Distant Metastasis, after Primary Surgery Followed by Mfolfox6 Plus Bevacizumab Treatment

Advances in chemotherapy and molecular targeting therapy have significantly improved the overall survival of colorectal cancer patients with distant metastasis. Our therapeutic strategy for colorectal cancer patients with distant metastasis is to perform surgery for the primary lesion for preventing bowel obstruction and tumor hemorrhage, followed by intensive chemotherapy. From 2008 to June, 31 colorectal cancer cases were retrospectively analyzed. Initially, the primary lesion was surgically resected. Subsequently, the mFOLFOX6 plus bevacizumab regimen was initiated. The response rate was 48%, and the disease control rate was 79%. After a median follow-up of 15.4-month, the median overall survival (OS) was 23.9 months. Therapy was not stopped in any patients because of hemorrhage or bowel obstruction. The reduction rate of the serum carcinoembryonic antigen (CEA) level correlated with the objective response. Patients who had at least a reduction in the serum CEA level seemed to have a longer OS than those who had no reduction (median OS: 23.9 vs 15.3 months, p = 0.015). The results showed that our strategy of combining primary surgery with chemotherapy is safe and effective. Furthermore, serum CEA level reduction seems to be a good prognostic predictor for colorectal cancer patients for whom this strategy is used.