Potential predictors of long-term survival after surgery for patients with stage IV colorectal cancer

Background: The prognosis of patients with colorectal cancer is considered to be affected by several factors. Recently, chemotherapy for this disease has been demonstrated to be effective for long-term survival. In this study, the potential predictors, including chemotherapy regimens for survival after surgery, in patients with stage IV colorectal cancer are presented. Patients and Methods: Univariate and multivariate analyses of potential predictors of survival after surgery were carried out for 56 patients with stage IV colorectal cancer who had undergone surgery, including 22 with rectal and 34 with colon cancer. Results: The survival in patients who had had a primary liver resection was longer than that in patients who had not (p = 0.007). There was a significant difference among chemotherapy regimens (p = 0.021). The survival in patients who were administered l-leucovorin/5-fluorouracil (l-LV/5FU) was longer than that in patients who received uracil-tegafur (UFT) and cisplatin (CDDP)/5FU (p = 0.024, p = 0.004, respectively). In multivariate analyses, there were 5 favorable factors that influenced overall survival after surgery: lymph node metastasis (p = 0.029), no bone metastasis (p = 0.012), no peritoneal invasion (p = 0.018), no primary liver resection (p = 0.004) and the chemotherapy regimen (p = 0.008). Furthermore, the survival in patients with a continued l-LV/5FU plus modified IFL regimen (additional irinotecan) was longer than for those patients who received other regimens, in both univariate and multivariate analyses. Conclusion: Five factors, namely lymph node metastasis, bone metastasis, peritoneal invasion, primary liver resection and chemotherapy, are potential predictors of survival after surgery for patients with stage IV colorectal cancer.