Background: In patients with asymptomatic colorectal cancer with irresectable metastatic disease, the optimal treatment strategy remains controversial. Resection of the primary tumor followed by chemotherapy when possible versus systemic chemotherapy followed by resection of the primary tumor when necessary are compared in this systematic review.
Patients and methods: Seven studies reported series of patients with asymptomatic stage IV colorectal cancer and compared first-line chemotherapy with surgery for the primary tumor (n = 850 patients). Primary outcome measure was the complication rate related to the primary tumor in situ in patients receiving first-line systemic chemotherapy.
Results: When leaving the primary tumor in situ, the mean complications were intestinal obstruction in 13.9% [95% confidence interval (CI) 9.6% to 18.8%] and hemorrhage in only 3.0% (95% CI 0.95% to 6.0%) of the patients. After resection, the overall postoperative morbidity ranged from 18.8% to 47.0%.
Conclusions: For patients with stage IV colorectal cancer, resection of the asymptomatic primary tumor provides only minimal palliative benefit, can give rise to major morbidity and mortality and therefore potentially delays beneficial systemic chemotherapy. When presenting with asymptomatic disease, initial chemotherapy should be started and resection of the primary tumor should be reserved for the small portion of patients who develop major complications from the primary tumor.