Chronicles of Cancer

Chronicles of cancer: A history of mammography, part 1

Technological imperatives


 

The history of mammography provides a powerful example of the connection between social factors and the rise of a medical technology. It is also an object lesson in the profound difficulties that the medical community faces when trying to evaluate and embrace new discoveries in such a complex area as cancer diagnosis and treatment, especially when tied to issues of sex-based bias and gender identity. Given its profound ties to women’s lives and women’s bodies, mammography holds a unique place in the history of cancer. Part 1 will examine the technological imperatives driving mammography forward, and part 2 will address the social factors that promoted and inhibited the developing technology.

All that glitters

Innovations in technology have contributed so greatly to the progress of medical science in saving and improving patients’ lives that the lure of new technology and the desire to see it succeed and to embrace it has become profound.

 image from Oak Ridge National Laboratories site. Public domain

Thorotrast bottle and box are shown.

In a debate on the adoption of new technologies, Michael Rosen, MD, a surgeon at the Cleveland Clinic, Ohio, pointed out the inherent risks in the life cycle of medical technology: “The stages of surgical innovation have been well described as moving from the generation of a hypothesis with an early promising report to being accepted conclusively as a new standard without formal testing. As the life cycle continues and comparative effectiveness data begin to emerge slowly through appropriately designed trials, the procedure or device is often ultimately abandoned.”1

The history of mammography bears out this grim warning in example after example as an object lesson, revealing not only the difficulties involved in the development of new medical technologies, but also the profound problems involved in validating the effectiveness and appropriateness of a new technology from its inception to the present.

A modern failure?

In fact, one of the more modern developments in mammography technology – digital imaging – has recently been called into question with regard to its effectiveness in saving lives, even as the technology continues to spread throughout the medical community.

A recent meta-analysis has shown that there is little or no improvement in outcomes of breast cancer screening when using digital analysis and screening mammograms vs. traditional film recording.

The meta-analysis assessed 24 studies with a combined total of 16,583,743 screening examinations (10,968,843 film and 5,614,900 digital). The study found that the difference in cancer detection rate using digital rather than film screening showed an increase of only 0.51 detections per 1,000 screens.

The researchers concluded “that while digital mammography is beneficial for medical facilities due to easier storage and handling of images, these results suggest the transition from film to digital mammography has not resulted in health benefits for screened women.”2

In fact, the researchers added that “This analysis reinforces the need to carefully evaluate effects of future changes in technology, such as tomosynthesis, to ensure new technology leads to improved health outcomes and beyond technical gains.”2

None of the nine main randomized clinical trials that were used to determine the effectiveness of mammography screening from the 1960s to the 1990s used digital or 3-D digital mammography (digital breast tomosynthesis or DBT). The earliest trial used direct-exposure film mammography and the others relied upon screen-film mammography.3 And yet the assumptions of the validity of the new digital technologies were predicated on the generalized acceptance of the validity of screening derived from these studies, and a corollary assumption that any technological improvement in the quality of the image must inherently be an improvement of the overall results of screening.

The failure of new technologies to meet expectations is a sobering corrective to the high hopes of researchers, practitioners, and patient groups alike, and is perhaps destined to contribute more to the parallel history of controversy and distrust concerning the risk/benefits of mammography that has been a media and scientific mainstay.

Too often the history of medical technology has found disappointment at the end of the road for new discoveries. But although the disappointing results of digital screening might be considered a failure in the progress of mammography, it is likely just another pause on the road of this technology, the history of which has been rocky from the start.

Pages

Next Article: