Prognostic factors and survival improvements in stage IV colorectal cancer*

BACKGROUND: The aim of the study was to evaluate prognostic factors and survival improvements in stage IV colorectal cancer patients who had all undergone resection of their primary tumor. METHODS: Between 1982 and 2006, 639 consecutive patients with UICC stage IV colorectal cancer underwent tumor resection followed by chemotherapy. Clinical, surgical, histopathological, and follow-up data were investigated and correlated with survival. RESULTS: Total R0 status was achieved in 101 patients (16%), and 128 patients (20%) underwent multivisceral resection. Median cause-specific survival for total R0 resected patients was 41 (95% CI: 32–50) months. The median cause-specific survival increased continuously from 10 (95% CI: 8–12) months for patients treated in the first years to 23 (95% CI: 19–27) months for those treated in the last 5 years of the study period. Multivariable analysis identified patients' age, pN, cM1a/b, R status, and the date of resection of the primary tumor as independent prognostic factors. CONCLUSIONS: Prognosis of stage IV colorectal cancer improved continuously in the last decades. Despite the ongoing discussion if the primary tumors should be resected in stage IV disease, prognostic factors can help to select M1 patients with potential long-term survival, who should undergo resection of the primary tumors and metastases followed by chemotherapy.