Unexpected peritoneal metastases diagnosed at the time of primary colon cancer resection: controversies regarding options for management.

Peritoneal metastases synchronously occurring in the patient with primary colon cancer causes that patient to be at high risk for subsequent disease progression within the abdomen and pelvis. If peritoneal metastases are preoperatively diagnosed, patients are likely to be treated with neoadjuvant chemotherapy with or without biological therapy prior to cytoreductive surgery (CRS). However, if one only considers patients with peritoneal metastases unexpectedly identified at the time of primary colon cancer resection, the optimal management strategy is neither standardized nor evidence based. These authors present an opinion regarding treatment options in unexpectedly (incidentally) detected peritoneal metastases. The primary colon cancer may be asymptomatic (elective list) or may present as an emergency with obstruction or with perforation. The fitness of the patient, the condition of the colon, availability of a colonic stent, consent of the patient and capabilities of the institution for management of peritoneal metastases by CRS and intraperitoneal chemotherapy cannot be ignored and must all be considered. These patients with known peritoneal metastases should not be allowed to return for further treatment with advanced disease after multiple regimens of systemic chemotherapy. Delay in definitive management will cause peritoneal metastases to be unresectable and not amenable to cure. It is time to debate optimal management strategies for unexpectedly detected peritoneal metastases. The authors find the data compelling that the modifications presented in the management of unexpected peritoneal metastases documented at the time of colon cancer resection changes a palliative approach to treatment to a plan that has curative intent.