Reassessing the need for primary tumor surgery in unresectable metastatic colorectal cancer: overview and perspective.

In the absence of symptoms, primary tumor resection in patients who present with unresectable metastatic colorectal cancer is of uncertain benefit. Prophylactic surgery has been traditionally considered in this setting in order to prevent subsequent complications of perforation, obstruction, or bleeding later during the treatment course, which may require urgent surgery associated with higher mortality. However, recent data have called into question the efficacy of this upfront surgical strategy. We provide a brief overview of how current combinations of systemic chemotherapy including fluorouracil, oxaliplatin, irinotecan, and targeted biologic agents have allowed improved local (in addition to distant) tumor control, significantly decreasing the incidence of late primary-related complications requiring surgery from roughly 20% in the era of single-agent fluoropyrimidine chemotherapy to almost 7% in the era of modern triple-drug chemotherapy. In addition, we attempt to highlight those factors most associated with subsequent primary tumor-related complications in an effort to identify the subset of patients with synchronous metastatic colorectal cancer who might benefit from a surgery-first approach. Finally, we discuss modern nonsurgical options available for palliation of the primary colorectal tumor and review the outcome of patients for which emergent surgery is eventually required to address primary-related symptoms.