Most Cancer Screenings Fail to Extend Lifespan, But Their Real Benefit is Less Obvious

Figure 1. SigmoidoscopyPhoto byCancer Research UK.

Key Findings: Limited Impact on Life Expectancy

A recent finding has been stirring the medical community. A comprehensive meta-analytical study of over 2.1 million individuals across 18 clinical trials with 10-15 years of follow-up has cast a shadow of doubt on the benefits of routine cancer screenings.

The study, titled "Estimated Lifetime Gained With Cancer Screening Tests: A Meta-Analysis of Randomized Clinical Trials," was published in JAMA Internal Medicine.

Photo byBretthauer et al., JAMA Internal Medicine.

It indicates that out of the six most common cancer screenings, only colorectal cancer screening using sigmoidoscopy (Figure 1) showed a significant and modest extension of life, approximately a little more than 3 months.

Other routine cancer screenings (i.e., prostate-specific antigen screening, computed tomography lung screening, fecal testing, and mammography) had no significant impacts on life expectancy.

But experts caution that this study doesn't invalidate the century-long practice of advocating for routine cancer checks but rather invites a more nuanced understanding of their benefits and limitations.

The Role of Cancer Screenings in Public Health

The American Cancer Society and the World Health Organization have long championed regular screenings as a vital public health approach, emphasizing early detection's role in improving cancer outcomes and reducing mortality rates.

Indeed, since 1991, overall cancer mortality has seen a significant drop of 33%, attributed to early detection, advancements in treatment, and reduced smoking rates.

But the researchers also caution against an uncritical endorsement of all screenings. While some screenings may show no significant impact on extending life, they may still hold value in reducing the incidence and mortality rates of certain cancers.

The emphasis, therefore, should be on balancing the absolute benefits of screenings with their potential harms and burdens.

Expert Perspective: The Real Value of Cancer Screenings

Dr. William Dahut of the American Cancer Society notes that while screenings may not dramatically alter overall mortality rates, they significantly reduce cancer-specific deaths and prevent early death from cancer.

In other words, Dr. Dahut explained that while a person might be expected to live until 80, undergoing cancer screening could prevent an untimely demise at 65. But this doesn't imply that the individual would surpass their anticipated 80 years to live until 90.

The discourse isn't about dismissing cancer screenings but rather recalibrating our expectations and understanding of their outcomes. The goal remains to enhance the quality and length of life through informed, personalized medical choices.