In this issue of JAMA, Buyse and colleagues1 present a meta-analysis of adjuvant therapy for colorectal cancer. They have previously provided information about meta-analysis,2 which is a new discipline that statistically combines and critically reviews the results of previous research. The purposes of meta-analysis include the following: (1) to increase statistical power for primary end points and for subgroups, (2) to resolve uncertainty when reports disagree, (3) to improve estimates of effect size, and (4) to raise and possibly answer questions not posed at the start of individual trials.
In this comprehensive review, Buyse and coworkers1 have assembled all randomized, controlled, clinical trials on adjuvant therapy for colorectal cancer published up to December 1986 in the English language. They excluded nonrandomized and "immature" trials and those using adjuvant liver perfusion. Among the 27 trials found, eight trials compared radio
See also p 3571. therapy with (surgical) control
Levin B, O'Connell MJ. Colorectal Cancer Chemotherapy: Meta-analysis or Large-Scale Trials?. JAMA. 1988;259(24):3611. doi:10.1001/jama.1988.03720240073039