Evaluation of new imaging procedures for breast cancer: proper process.

Abstract

Since breast cancer will affect one out of 1 1 American women during their lifetimes, it is a major target of medical research. Mammography has been in the forefront of this effort because of accumulating evidence that early detection improves prognosis and because of the demonstrated ability of mammography to detect cancer at a nonpalpable stage [1 ]. However, its widespread use has been tempered by the issue of possible risk from low doses of ionizing radiation as well as by the fact that, although more accurate than any other detection method, including physical examination, it may still find only 80%-9O% of breast cancers [1]. These factors have served to stimulate some medical investigators and manufacturers of equipment to explore alternative breast imaging procedures such as telethenmognaphy, graphic stress thermography, cholesterol plate thenmography, sonography, and diaphanography. For several reasons these studies have not always had the rigorous evaluation they deserve. In some cases commercial incentives have led to the hasty marketing of equipment before its accuracy (or lack of accuracy) was fully known. In other instances personal and professional motives have caused some investigators to announce a research “breakthrough” based on poorly designed and/or poorly analyzed studies. Companies may provide these investigators with professional forums and research funds at a time when government grants are in short supply. Thus, the investigators may become unwitting partners in unscientific misadventures. That many women are highly aware of breast cancer yet unnecessarily apprehensive of the medical x-ray exposure is ironic. Many seek reassurance that they do not have a breast cancer yet hesitate to get a mammognam because they have heard from the news media about the possible radiation risk. The potential tragedy is that large numbers of tiny cancers could be lost to early detection through such misguided apprehension. The risk may be much greaten than the theoretical risk from properly executed mammography [2-4]. New imaging methods are understandably attractive but their evaluation has been relatively inefficient. Through trial and error new methods find some level of acceptance by the medical community. The process has been expensive, time-consuming, and unscientific. In terms of breast disease, however, this may not be its main failure. If a new method, such as thermography, sonography, computed tomognaphy (Cl), or diaphanognaphy, is not proven to detect very small, highly curable breast cancer, its wide use may delay diagnosis significantly and lead to otherwise avoidable loss of life. Diagnostic imaging procedures that do not detect lesions at an earlier stage than current clinical practice do nothing but add unproductive expense to the cost of medical care and set attitudes that may be difficult to change. For example, the widespread implementation of thenmography before its role in breast cancer detection was firmly determined led to unrealistic expectations, followed by ne-