Alan P. Venook, MD

Anti-EGFR therapy is a valuable addition to the armamentarium of treatment options for patients with metastatic colorectal cancer. However, RAS mutation status is an imperfect biomarker for prediction of therapeutic outcomes in this setting. The recent discovery of tumor sidedness as a predictor of response highlights how little we understand about which patients are the most appropriate to receive drugs that target EGFR.

A retrospective analysis of a phase III clinical trial found that the physical location of the primary tumor predicts survival in patients with metastatic colorectal cancer.

At this juncture, various commercially available assays for colon cancer may be of little added value, and accelerated biomarker development with clinical validation is desperately needed.

Combined-modality therapy has rendered disease-free an increasing number of patients who were previously considered to be incurable. Still, despite myriad advances in imaging, and in surgical and therapeutic modalities, many patients who undergo resection of limited metastatic disease with curative intent ultimately relapse.

Preliminary results from two trials presented at the 44th Annual Meeting of ASCO in Chicago have consolidated the role of K-ras as a biomarker of nonresponse to cetuximab and panitumumab in metastatic colorectal cancer (mCRC). The phase III CRYSTAL and OPUS trials presented unplanned subgroup analyses of the correlation of K-ras status with response to therapy with first-line FOLFIRI or FOLFOX, respectively, with or without cetuximab in patients with mCRC. Both studies demonstrated a clear benefit with the addition of cetuximab in K-ras WT patients.

Epothilones, representing a newer class of naturally occurring antimicrotubule macrolides, have emerged as cytotoxic agents with significant antitumor activity against tumors that are resistant to taxanes.

The liver is a frequent site of metastatic colorectal disease. Over the past 20 years, improvements in systemic chemotherapy and surgical techniques have improved the survival of patients with hepatic metastases. For 4 decades, fluorouracil and leucovorin were the only drugs available to treat metastatic colorectal cancer, but several new drugs and a variety of novel regimens are now available. Further improvements in results have been seen with the delivery of chemotherapy via the hepatic artery. Surgical resection of liver metastases has been encouraged when possible, and recent advances in surgery such as portal vein embolization, have made liver resection a possibility for more patients. This review considers the timing and sequence of chemotherapy and surgery in this setting, as well as the roles of cryoablation, radiofrequency ablation, and radiation therapy.

The dosing of chemotherapy is,at best, an imperfect science.Long-standing convention hasus calculating body surface area totwo decimal places-a largely discreditedand unnecessary exercise-yet wehave so far failed to learn how to incorporatepotentially important variablesrelated to race, sex, and pharmacogenetics.This review, “ChemotherapyDosing in the Setting of Liver Dysfunction,”by Eklund et al highlightsanother limitation in our understandingof how to use chemotherapy: There islittle known about how to dose drugs inpatients with anything other than normalorgan function.

The use of hepatic arterial infusion (HAI) chemotherapy in patientswith liver-only colorectal metastases is based on the pharmacologicprinciple that the regional administration of some drugs can lead tohigher drug concentrations at the site of the metastases and avoid systemictoxicity. Early randomized trials resulted in high response ratesbut did not lead to a survival advantage with HAI. More recent trialshave utilized improved surgical techniques and strict guidelines regardingdose reduction or cessation of HAI chemotherapy, resulting in asignificant reduction in toxicity. In patients with unresectable liver metastases,two recent European trials using HAI fluorouracil (5-FU)again failed to demonstrate an improvement in survival, but both wereplagued by a high complication rate with an associated high proportionof patients failing to receive the assigned treatment. In contrast,the preliminary results of a recent Cancer and Leukemia Group B trialdid demonstrate a survival advantage with HAI floxuridine when comparedto systemically administered 5-FU. Trials investigating the useof HAI chemotherapy in the adjuvant setting have yielded mixed results.Moreover, in light of improved response rates and overall survivalwith newer more active chemotherapeutic and novel agents, theabsolute role of HAI chemotherapy remains undefined.

Since hepatocellular carcinoma almost always develops in patients with underlying hepatitis or cirrhosis of the liver, it cannot be viewed as a single disease. Not only does the biology of the cancer vary depending on the underlying etiology of the liver disease-hepatitis B, hepatitis C, or cirrhosis of another etiology-but also patient outcomes are determined by the interplay between tumor growth and

The use of hepatic intra-arterial (HIA) chemotherapy is based on the pharmacologic principle that the regional administration of certain drugs can lead to higher drug concentrations at the site of a tumor. This has been studied most extensively in patients with liver-only colorectal metastases. Four large randomized studies have failed to demonstrate a survival advantage of regional treatment over systemic chemotherapy, although two meta-analyses confirmed an improvement in response rate and suggest a trend toward improvement in survival. Two randomized studies have shown improved survival in patients treated with HIA chemotherapy, as compared with those given supportive care, and quality of life also appears to be superior in HIA chemotherapy recipients. The treatment employed in all of the randomized studies was hindered by substantial hepatobiliary toxicity and many surgical complications. Improved surgical techniques and newer chemotherapy combinations appear to have improved phase II results with HIA therapy, leading to a randomized trial now being conducted by the Cancer and Leukemia Group B (CALGB). The role of HIA chemotherapy in adjuvant settings and in other diseases has not been as well-studied, and such uses remain appropriate only for very selected patients. Ultimately, the regional advantage gained by the HIA route may prove to be most advantageous for the delivery of newer biologic agents. [ONCOLOGY 11(7):947-957, 1997]