Potential and pitfalls of randomized clinical trials in cancer research.

Randomized clinical trials are a powerful tool to establish the superiority of investigational therapies over standard ones. Yet in cancer, particularly in colorectal cancer, the results of clinical trials have been disappointing and have raised some suspicion about the real worth of randomization. This paper attempts to show that the results of randomized trials have often been misinterpreted, either because they were subject to various sources of biases or because their statistical power was too low to allow a reasonably reliable assessment of true treatment benefits.