OncoSurge: A strategy for long-term survival in metastatic colorectal cancer

OncoSurge is a combined modality strategy for the management of colorectal cancer with hepatic metastases. It has emerged as a result of new and expanded patient selection criteria for resectability of metastases, coupled with more effective neoadjuvant and postoperative chemotherapy. By bringing together these developments in surgery and medical oncology, the new approach promises to increase significantly the resectability rate and long-term survival in colorectal cancer patients with liver metastases. Surgery for colorectal liver metastases should now be considered across a range of clinical circumstances that would historically have been contraindications to resection. These contraindications include multiple or bilobar metastases, large tumour size, a Dukes stage C or poorly differentiated primary tumour, synchronous detection of metastases with the primary tumour, disease in elderly patients, or a resection margin of less than 1 cm. None of these criteria should necessarily exclude a patient from resection, brecause although they may be associated with a less favourable prognosis they do not exclude the possibility of long-term survival. Non-resectable extrahepatic disease and portal lymph node involvement, however, remain contraindications to resection in most circumstances. Retrospective studies of neoadjuvant therapy have indicated that a regimen based on low dose oxaliplatin, 5-fluorourucil (5-FU) and leucovorin increased the overall resectability rate of patients presenting with hepatic colorectal metastases from 20% to 30%, with 13.6% of patients with unresectable metastases becoming eligible for curative resection. More recently, studies using more potent oxaliplatin-based regimens have reported significantly higher resectability rates of at least 40%, with 5-year survival of 50% reported in one large study among patients whose liver metastases were resected after initial neoadjuvant therapy for unresectable tumours. Following resection, postoperative therapy based on a combination of hepatic artery infusion (HAI) and systemic chemotherapy reduces hepatic recurrence and increases survival, but more potent systemic therapy is required to reduce the rate of extrahepatic recurrence. Studies are now in progress combining HAI with oxaliplatin-based systemic therapy to address this issue. By combining a more inclusive approach to surgery with more effective neoadjuvant and postoperative chemotherapy, the OncoSurge treatment model is likely to increase significantly the number of patients with hepatic colorectal metastases who can be treated with curative intent, and thus has the potential to improve overall patient survival.