It takes a village…

Abstract

2These authors have much in common with the Task Force. They, like the TF: are concerned to quantify the aggregate benefit from the screening for some defined type(s) of population for which public policy is, or might be, in favour of the screening; think of this benefit for any such population in terms of the proportional reduction in mortality from the cancer; think that a measure of this reduction can be derived from the studies that have addressed the counterpart of this reduction in experimental cohorts; are not concerned to judge whether the diagnostic work-ups and treatments in a given trial, even dating from a half-century ago, have relevance to practices at present and beyond; do not view it relevant to take note of the protocols for and practices of the diagnostic work-ups and treatments in those studies; and finally, do not think it necessary to judge the validity of the trials used for quantification of the mortality reduction, even if major problems of validity in them are well known. In this aggregate of principles, the inattention to the well-known problems of validity in the trials is particularly surprising. Suffice it to note that while much emphasis is placed on the trials being randomized, even this feature of them has been prone to be invalid. Thus, S. Mukherjee, in his “biography of cancer”, 3 points out and explains how the HIP trial was “instantly a logistical nightmare” (p. 295); and how, in this trial, “The unscreened group had been mistakenly overloaded with patients with prior breast cancer” (p. 297; italics in the original). He also points out and explains how “The [Canadian National Breast Screening Study] faltered, …, by succumbing to the opposite sin: by selectively enriching the mammography group with high-risk women” (p. 299; italics in the original). On the other hand, Hanley et al. diverge, profoundly, from the Task Force in the way they think of, and derive, the results from the trials; and in this, these authors take major exception also to the culture that the TF in this respect shares with the trialists them