Re: Cancer Chemoprevention: Progress and Promise RESPONSE

Abstract

The commentary by Lippman et al. ( 1 ) provides a useful review of the topic by organizing a massive amount of information in an organized way. However, because this review will be widely read and referenced, there are two general points made by the authors that could be challenged. The authors define two of the four criteria for identifying a “ definitive” chemoprevention trial as “primary end point of cancer incidence” and “large scale (n ⩾ 1000) with the definitive sample size and duration based on anticipated event rates in the intervention arm (treatment effect) and placebo arm.”