How Beneficial Is Early Detection Screening for the 5 Most Common Cancers?

The Power of Prevention and Screening

Over the past 45 years, prevention and screening have averted more deaths from five cancer types than advances in treatment. This striking result comes from a modeling study conducted by researchers at the US National Institutes of Health (NIH) and published in JAMA Oncology on 5 December 2024. The study examined deaths from breast, cervical, colorectal, lung, and prostate cancers averted through advances in prevention, screening, and treatment.

The image above explains the stages of cancer prevention, screening, and treatment. A system of pipes represents different stages of disease and the interventions used at each stage:

1. No Disease: At this stage, disease has not yet developed. However, in some cases, it may develop despite preventive efforts. Cancer prevention strategies can prevent up to 50% of all cancers.

2. Preclinical Disease: The disease is at an early stage and has not yet caused symptoms. Without screening, it may go unrecognized at this stage.

3. Clinical Disease: Symptoms have appeared, and a clinical diagnosis has been made. However, the disease may progress despite treatment.

4. Disease-Specific Death: If treatment cannot bring the disease under control, death from the disease may occur.

More Effective Than Treatment in Reducing Deaths by 80%

Together, these five cancer types account for approximately half of all cancer cases, in terms of both new diagnoses and deaths. Understanding which approaches work best in these cancers, where prevention, early detection, and treatment strategies are available, is critical to guiding future strategies. One of the lead researchers, Dr. Katrina A. B. Goddard, said, “The fact that prevention and screening account for 80% of the deaths averted from these five cancers over the past 45 years shows how powerful these strategies are,” she explained.

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Study Details

Modeling death rates from breast, cervical, colorectal, lung, and prostate cancers between 1975-2020, researchers estimated that a total of 5.94 million deaths were averted in the United States alone. Prevention and screening interventions accounted for 4.75 million (80%), while treatment advances contributed the remaining 20%.

Contributions to Averting Deaths by Cancer Type

1. Breast Cancer:

   • Against 2.71 million deaths, 1 million deaths were averted.
   • Treatment advances accounted for 75% of the averted deaths, with mammography screening accounting for the remainder.

2. Lung Cancer:

   • Against 9.2 million deaths, 3.45 million deaths were averted.
   • Smoking cessation efforts contributed 98% of the averted deaths, while treatment accounted for 2%.

3. Cervical Cancer:

   • Against 370 thousand deaths, 160 thousand deaths were averted.
   • Screening methods such as Pap smears and HPV testing accounted for all the averted deaths.

4. Colorectal Cancer:

   • Against 3.45 million deaths, 940 thousand deaths were averted.
   • Screening and polyp removal contributed 79%, while treatment contributed 21%.

5. Prostate Cancer:

   • Against 1.01 million deaths, 360 thousand deaths were averted.
   • PSA testing contributed 56%, and treatment advances contributed 44%.

The Future of Prevention and Screening

Study author Dr. Philip E. Castle noted that newer prevention and screening strategies are not yet widely used but could further reduce future death rates. In particular, HPV vaccination and lung cancer screening could have a major impact in the years ahead. Innovations such as HPV tests that enable self-screening also aim to expand access to screening.

Remaining Gaps and New Opportunities

The study focused on only five cancer types and noted gaps in prevention and screening for other deadly cancers, such as pancreatic and ovarian cancer. It also did not assess false-positive screening results or effects on quality of life. Despite these limitations, integrating prevention, screening, and treatment stands out as an important strategy for reducing cancer deaths.

Conclusions and Recommendations

The study again emphasizes the power of prevention and screening in cancer control. However, increasing their impact requires addressing barriers to access, developing new technologies, and expanding their use, particularly among socioeconomically disadvantaged groups.

As coauthor Dr. W. Kimryn Rathmell noted, “Combining effective prevention and screening strategies with treatment advances is vital in the fight against cancer. This synergy could mark a turning point in reducing cancer deaths.”