Weijing Sun, MD, FACP

“...we don’t focus on survivorship enough. It’s important to understand the other factors involved in surviving besides just a treatment.”

It remains difficult to decipher which patients are appropriate candidates for conversion therapy vs upfront surgery. Therefore, in predicting potential outcomes, several factors should be considered. Here, we will attempt to address such factors and provide insights.

Due to advances in chemotherapy, biologic therapy, and the development of liver-oriented treatment options, the survival of patients with metastatic cancer has more than doubled, and increasing numbers of patients have been cured, even among those with advanced disease.

Advances in the treatment ofmetastatic colorectal cancer inthe past several years havebeen expeditious and exciting-evenchaotic-but with the median survivaldoubled since the use of single-agentfluoropyrimidines alone. However, newquestions continue to arise, directly affectingour daily practice in the care ofpatients with colorectal cancer. One ofthese issues, the optimal therapy formetastatic colorectal cancer, is wonderfullyexplored by Dr. Saltz in thisissue of ONCOLOGY. To understandthis issue better, we may have to approachthe question a little differently:That is, is it possible to standardizetreatment options for metastatic colorectalcancer?

From the results of recent studies, it is likely that multimodality therapy with chemotherapy and radiation treatment may improve the overall outcome of locally advanced upper gastrointestinal (GI) malignancies, including esophageal, gastric, pancreatic, and biliary tract carcinomas. However, more effective, more optimal, and less toxic chemotherapy regimen(s) with concomitant radiotherapy are needed beyond the concurrent continuous-infusion fluorouracil (5-FU) with radiation that is commonly applied in general practice. Epirubicin (Ellence), cisplatin, and irinotecan (Camptosar) are all active cytotoxic chemotherapy agents in upper GI cancers. Two phase I studies were designed to test the tolerability of the combination of radiotherapy with infusional 5-FU, epirubicin, and cisplatin (ECF) or 5-FU, irinotecan, and epirubicin (EIF) in the treatment of locally advanced upper GI malignancies.

It is a continuing challenge for oncologists to effectively treatadvanced/metastatic pancreatic and biliary cancer. Both irinotecan(CPT-11, Camptosar) and gemcitabine (Gemzar) have shown activityagainst these diseases with different mechanisms. Preclinical andclinical data also suggest additive or synergistic effects of the combinationof these two agents with few or no overlapping toxicities. Phosphorylationof gemcitabine, a process of intracellular activation of theagent, is dose-rate dependent. It has been suggested that the fixed-doserateinfusion of gemcitabine increases the concentration of intracellulartriphosphate gemcitabine, which in turn may result in more objectiveresponses and longer median survival compared to the standard infusion.This phase I study tests the toxicity of the combination of irinotecanwith fixed-dose-rate infusion of gemcitabine, and determines thedose of the combination for phase II investigation.

The article by Drs. Khayat and Gil-Delgado outlines the exciting new developments in the treatment of advanced colorectal cancer with irinotecan (CPT-11 [Camptosar]) and oxaliplatin. Although the development of these drugs provides an alternative to fluorouracil (5-FU) in the treatment of this common tumor, it is still unclear how to optimally integrate these promising compounds into therapy for colorectal cancer.

UFT and leucovorin (Orzel) is a combination of tegafur and uracil in a molar ratio of 1:4. Tegafur, a prodrug of 5-fluorouracil (5-FU), is converted to 5-FU by the hepatic cytochrome P450 pathway, whereas uracil enhances the

The combination of irinotecan and fluorouracil (5-FU) is synergistic when applied to human colon cancer cell lines in vitro and appears to be schedule-dependent: maximal activity occurs when irinotecan is administered prior to 5-FU. In this phase I study, irinotecan is administered in combination with UFT and leucovorin in patients with advanced solid tumors.