Survival and response to chemotherapy for advanced colorectal adenocarcinoma: an Eastern Cooperative Oncology Group report.

A series of 1,314 cases of advanced measurable colon or rectal cancer were evaluated for objective tumor response and survival. All patients received chemotherapy according to protocols conducted by the Eastern Cooperative Oncology Group during the period between 1974 and 1977. For those patients who had not received chemotherapy prior to study entry, no therapy program under evaluations was significantly more active than the oral or intravenous 5-fluorouracil treatment programs with respect to survival or objective tumor response. The survival and response rates therapy programs under study, including methyl-CCNU, appeared to be comparable. Initial performance status (P < 0.01), weight loss in the six months prior to study entry (P < 0.001), and prior chemotherapy status were shown to be most prognostic for survival, and thus merit inclusion as stratification factors in any comparative trial involving this population. These factors were shown to have a cumulatively greater influence upon survival than the treatment program. Treatment differences were most accentuated within the favorable subgroups of the leading prognostic factors. The location of the primary tumor had a significant effect upon the eventual sites of metastatic disease involvement at the time of study entry (P < 0.001). The consequences of this analysis suggest that investigators need to address characteristics of the population under study. It is also noted that patients with chemotherapy prior to study entry are best suited for survival studies, while patients with no chemotherapy prior to study entry are well suited for both objective tumor response and survival studies.