Molecular predictors of treatment and outcome in colorectal cancer

Multidisciplinary approach of colorectal liver metastases

Colorectal cancer (CRC) is the second most common cause of cancer death in Spain. Fifty percent of patients will develop colorectal liver metastases (CLM) during the course of the disease. Less than 20% of patients with CLM are initially resectable and for them 5-year disease-free survival (DFS) is about 20-25%, with a high recurrence rate. CLM is a heterogeneous disease. From a clinical point of view, four main groups can be differentiated: initially resectable, not optimally resectable, unresectable that could be resectable and unresectable that never will be likely to be resected. Treatment of CLM must be established, always, in a multidisciplinary team discussion with an analysis of prognostic factors and resectability. For patients with resectable CLM, the EORTC trial 364 demonstrated that chemotherapy plus surgery is better than surgery alone. Consequently most patients should be treated with perioperative chemotherapy based on oxaliplatin, and if resection has been done without chemotherapy, they should receive adjuvant chemotherapy after R0 resection. Based on oncological factors, the 5-year survival rate after resection of CLM ranges from 60% to only 14% with a poor score. If a patient has more than one of the poor prognostic factors he should probably be referred for preoperative (induction) chemotherapy. Only a minority of patients with CLM are amenable to surgery; therefore, efforts have been made to increase the percentage of patients who could be candidates for resection. Studies, mostly retrospective, have confirmed the ability of neoadjuvant chemotherapy (conversion chemotherapy) to render some metastases resectable. The regimens we must use depend on the KRAS mutational status and the toxicity profiles of drugs in the context of each patient. In k-ras mutated tumours we can use bevacizumab combined with standard chemotherapy or concomitant administration of the three active agents (FOLFOXIRI) in suitable patients. In k-ras wild-type patients, the combination of cetuximab and FOLFIRI-FOLFOX improved response rates and resection rate in phase III-II trials. With a lower level of evidence, panitumumab is an alternative combined with FOLFOX. Bevacizumab is also an alternative as it does not depend on KRAS status. Radiotherapy is becoming an alternative in selected patients, where surgery is not an alternative. For the majority of patients, who will never be resectable, the continuum of care with chemotherapy will be the paradigm for their management.

Towards a pan-European consensus on the treatment of patients with colorectal liver metastases

Colorectal cancer (CRC) caused nearly 204,000 deaths in Europe in 2004. Despite recent advances in the treatment of advanced disease, which include the incorporation of two new cytotoxic agents irinotecan and oxaliplatin into first-line regimens, the concept of planned sequential therapy involving three active agents during the course of a patient's treatment and the integrated use of targeted monoclonal antibodies, the 5-year survival rates for patients with advanced CRC remain unacceptably low. For patients with colorectal liver metastases, liver resection offers the only potential for cure. This review, based on the outcomes of a meeting of European experts (surgeons and medical oncologists), considers the current treatment strategies available to patients with CRC liver metastases, the criteria for the selection of those patients most likely to benefit and suggests where future progress may occur.

Adjuvant Therapy for Colon Cancer 2005: New Options in the Twenty-First Century

The most effective current regimen for adjuvant treatment of surgically resected stage III colon cancer is the FOLFOX regimen of oxaliplatin, 5-FU and LV for 12 weeks, with a proportional risk reduction of 45% compared with approximately 36% for 5-FU/LV regimens. Infusion regimens of 5-FU with and without LV have been shown to confer equivalent benefit to bolus regimens in reducing the risk of cancer recurrence, but with lesser toxicity profiles. Oral 5-FU prodrug regimens have similarly shown equivalent benefit to bolus regimens, and toxicity comparable to infusional regimens, but with the added convenience over 5-FU infusion therapy. The addition of irinotecan to 5-FU and LV regimens has not demonstrated an advantage compared with 5-FU/LV treatments in the adjuvant setting.