Commentary

Cancer screening: A modest proposal for prevention

Author and Disclosure Information

 

References

I have been assured by a very knowing American of my acquaintance in London, that a young healthy child well nursed is at a year old, a most delicious, nourishing, and wholesome food, whether stewed, roasted, baked, or boiled, and I make no doubt that it will equally serve in a fricassee, or ragout.

—Jonathan Swift, A Modest Proposal1

Large-scale cancer screening programs have the unintended consequences of false-positive results and overdiagnosis, leading to anxiety and overtreatment. The magnitude of these harms continues to be clarified after decades of screening.

Recognizing the trade-off between benefits and harms, the US Preventive Services Task Force (USPSTF) has changed several of its recommendations in recent years. Breast cancer screening recommendations have gone from yearly mammograms starting at age 40 to biennial mammograms starting at age 50 for women at average risk.2 Prostate cancer screening is no longer recommended for men age 70 and older, and even for men between 55 and 69, screening is now an individual decision.3

Newer screening programs are targeting high-risk groups rather than the general population, with the aim of increasing the likelihood of benefits and limiting the harms. For example, lung cancer screening is recommended only for current smokers or smokers who have quit within the past 15 years, are between 55 and 80, and have at least a 30 pack-year smoking history.4

The movement toward less-frequent screening and screening in a narrower population has evoked strong reactions from advocates of cancer screening. One professor of radiology writes, “It borders on unethical to suggest that the benefit of having your life saved by screening and living another 40 years can be balanced against the ‘harm’ of being recalled for additional mammographic views for what proves to not be a cancer.”5 Another notes, “It does not make any sense to throw away the lives saved by screening to avoid over-treating a small number of cancers.”6 Both of these authors defend the position that the goal of screening is to minimize cause-specific mortality, irrespective of overdiagnosis, overtreatment, or false-positive results. In other words, harm should have little to no weight in screening recommendations.

Although the debate on cancer screening is moving toward a more balanced discussion of benefits and harms, many patients are still subjected to screening that is more aggressive than the USPSTF recommends, which may be due to an underlying belief that no harm is greater than the benefit of saving a life.

IS MORE-AGGRESSIVE SCREENING THE ANSWER?

Table 1. Benefit of cancer screening
Worst of all, when we examine the numbers, cancer screening is not very effective (Table 1).2–4,7,8 Even using optimistic estimates of its benefit, it is at best a half measure. Although screening, by detecting more cases of cancer at an early, potentially treatable stage, does save some lives from that cancer, many more people continue to die of cancer in spite of screening.

One may wonder if more-aggressive screening could prevent deaths that occur despite standard screening. For example, more-frequent screening or use of additional screening methods such as ultrasonography or magnetic resonance imaging has been suggested for patients at high risk of breast cancer.

A MODEST PROPOSAL

If one holds the view that benefits alone should be considered when writing recommendations about screening, the logical conclusion extends beyond screening. We would therefore like to propose a different approach to reducing cancer deaths in the general population:

Why not just remove everybody’s breasts, prostate gland, and colon before cancer arises?

Next Article:

Managing malignant pleural effusion

Related Articles