Abstract
OBJECTIVE: To compare the survival of palliative stage IV colorectal cancer patients selected for primary tumor resection and systemic treatment (PTR+SYST) to patients with systemic treatment only (SYST). BACKGROUND: About 20-25% of all colorectal cancer patients are diagnosed with stage IV disease. The benefit of primary tumor resection in the palliative situation is therefore of high concern. However, empirical evidence from randomized and observational studies is inconsistent. METHODS: Mortality after PTR+SYST was compared to systemic treatment alone in a retrospective observational cohort of patients diagnosed 2012-2020 from the cancer registry in the federal state of Brandenburg (Germany), excluding patients with rectal cancer of the lower two-thirds, emergency procedures, unknown ECOG status, ECOG greater than 2, unknown metastatic status or unclear grading. RESULTS: Of 480 patients, 416 died during an average follow-up of 23 months in mean. Twelve-month survival was 75% after PTR+SYST compared with 49% after SYST [hazard ratio (HR)=0.39, 95% CI 0.29-0.53, P <0.001]. The difference persisted to 36 months (28% vs. 13%, HR=0.53, 95% CI 0.43-0.66, P <0.001). Results were similar after multivariate adjustment, propensity score matching and delayed entry. CONCLUSION AND RELEVANCE: Patients with stage IV colorectal carcinoma who are selected for primary tumor resection in combination with systemic therapy and who receive such treatment survive longer compared with patients who receive only systemic treatment. Whether the difference is due to the selection of patients or PTR remains unclear. At present, the current practice of selecting patients for PTR appears to do no harm.