Hidden Opportunities in Cytoreductive Surgery for Peritoneal Carcinomatosis of Colorectal Origin

Abstract

The optimal management of peritoneal carcinomatosis of colorectal origin remains a challenging clinical problem characterized by more questions than answers. In recent years there has been a great expansion of therapeutic options for patients with metastatic colorectal cancer. Newer and more effective systemic chemotherapeutic agents (e.g., oxaliplatin and irinotecan), targeted biologic therapies (e.g., bevacizumab, cetuximab, panitumumab) and advances in surgical indications for resection of visceral metastases have greatly improved survival outcomes. However, for the more than 15% of patients with colorectal cancer who develop peritoneal metastases, data to guide their therapy are limited, often resulting in treatment decisions based upon strong patient and provider convictions rather than established experimental evidence. Fortunately, significant efforts to improve the poor prognosis for these patients are ongoing. One of the most notable efforts is increased use of the combination treatment of cytoreductive surgery (CS) with perioperative (intra- or postoperative) intraperitoneal chemotherapy (PIC) with or without hyperthermia. Using this approach, single-center reports have noted 5-year survival rates of 20% to over 40% for patients treated with CS and hyperthermic intraperitoneal chemotherapy (HIPEC)—twice the expected survival with systemic 5-fluorouracil chemotherapy alone. 1–3 Consequently, these and other data have led to a recent consensus statement advocating the use of CS and PIC in patients with peritoneal carcinomatosis from colorectal cancer. 4 In this issue Franko and colleagues report a retrospective analysis of prospectively collected data from their single-institutional experience regarding multivisceral resection (MVR) during the course of CS and HIPEC for colorectal peritoneal carcinomatosis (n = 65). 5 The purpose of their study was to evaluate the impact of MVR during CS and HIPEC on morbidity and survival outcomes. The overall morbidity rate in this study was 60%. The performance of a bowel anastomosis was an important identified risk factor of significant increase in morbidity (70% with anastomosis versus 33% without, P = 0.003) including increased rates of reoperation, wound complications, enterocutaneous fistulae, and prolonged ileus. MVR, defined as the resection of two or more organs beyond peritonectomy and omentectomy, was performed in 35 of 65 patients (54%). MVR was not associated with significant differences in perioperative morbidity or mortality compared with patients who did not require MVR during CS. Additionally, patients who underwent complete or nearly complete cytoreduction (defined as residual tumor implants <5 mm) had significantly better median survival after CS and HIPEC compared with patients who had an incomplete cytoreduction (20.2 versus 10.6 months, P < 0.001) The performance of MVR did not affect median survival after CS and HIPEC—neither from the time of diagnosis of stage IV disease nor from the time of CS and HIPEC. At least two important messages are highlighted by the authors’ findings. Firstly, peritoneal cytoreduction with HIPEC is a potentially effective modality for selected patients with colorectal-cancer-associated peritoneal carcinomatosis. Secondly, the key to