The prognostic factors of stage IV colorectal cancer and assessment of proper treatment according to the patient's status

Background and aims: Approximately 20% of patients with colorectal cancer are initially diagnosed with stage IV. The majority has non-curative metastases, and their chances of survival are pitiful. This study evaluated the prognostic factors of survival and the access to the effective treatment in accordance with patients. Materials and methods: We retrospectively analyzed 503 patients for demographics, tumor characteristics, the treatment modality, and the survival outcome. Curative operation was performed in 127 patients and palliative operation in 376 patients. Results: For the curative operation group, the 5-year survival rate was 34.5%, and the prognostic factors of survival and recurrence were male gender (p=0.003, 0.009), pathologic N stage (p<0.001, p=0.002), and perineural invasion (p=0.003, p=0.026), respectively. For the non-curative operation group, the 5-year survival rate was 0%, and the median survival duration was 16.5 months. The potential predictors of survival for the palliative operation group were carcinoembryonic antigen level (p=0.013), differentiation of tumor (p=0.011), resection of primary tumor (p<0.001), and chemotherapy (p<0.001). But for the 131 patients with asymptomatic incurable disease, only chemotherapy was related to survival (p<0.001). Conclusions: The potential predictors of survival for curative stage IV colorectal cancer were male gender, pathologic N stage, and perineural invasion. Resection of the primary tumor and chemotherapy showed benefit for the incurable patients. But for the asymptomatic incurable patients, only chemotherapy prolonged the survival.