Written and edited by Abel B. Daartey, PharmD

An estimated 2,114,850 people in the United States will receive a cancer diagnosis in 2026, and 626,140 people will die from the disease. The better news is that the cancer death rate has fallen substantially since its 1991 peak, with about 4.8 million cancer deaths averted. Screening and earlier detection are part of that progress, together with less smoking and better treatment [1].

But screening is not automatically good just because it finds something early. A good screening test must do more than detect cancer. It should lower the chance of dying from that cancer, and the benefit should be bigger than the harms from false alarms, biopsies, unnecessary treatment, and fear.

Where Screening Saves the Most Lives

The strongest screening programs usually work because they find cancer early or detect a precancerous change before cancer starts. Cervical cancer screening is a good example. HPV testing and Pap testing can find infection or abnormal cells before invasive cancer develops. In late 2025, the American Cancer Society updated its cervical cancer screening guideline to include self-collected HPV samples as an option for some people, although provider-collected HPV testing is still preferred [2,3].

Colorectal cancer screening also has a strong evidence base. Stool-based tests such as FIT can find hidden blood, while colonoscopy can find and remove precancerous polyps. A 2024 JAMA Network Open study found that FIT screening was associated with lower risk of dying from colorectal cancer [4]. Colonoscopy evidence also supports major benefit, although the exact mortality reduction varies by study design, population, and adherence.

Lung cancer screening is different because it is not for everyone. Annual low-dose CT is recommended mainly for adults with a heavy smoking history who are current smokers or quit within the past 15 years. The NELSON trial and other evidence show that low-dose CT can reduce lung cancer mortality in properly selected high-risk groups [5].

When Screening Finds Too Much

Overdiagnosis means finding a cancer that would never have caused symptoms or death during the person’s lifetime. That is hard to explain because the word “cancer” sounds urgent. But some cancers grow so slowly that treatment may cause more harm than the disease itself.

Prostate cancer is one of the clearest examples. PSA testing can find aggressive cancers, but it also finds many low-risk tumors. The U.S. Preventive Services Task Force recommends that men ages 55 to 69 make an individual decision about PSA screening after discussing benefits and harms with a clinician, and it recommends against routine PSA screening for men 70 and older [6].

Thyroid cancer shows the same problem on a larger scale. More imaging finds more tiny papillary thyroid cancers, but many would never have caused harm. A 2026 JAMA Network Open study estimated that 72% to 94% of papillary thyroid cancers diagnosed between 1991 and 2019 were overdiagnosed [7]. Mammography also has an overdiagnosis problem, although it still reduces breast cancer mortality when used in recommended age groups.

Not Everyone Benefits Equally

Even when screening works, access is not equal. Rural communities, lower-income groups, uninsured people, and some racial and ethnic minority groups are more likely to miss recommended screening and more likely to be diagnosed at later stages. This is not just about knowledge. It is also about insurance, transportation, clinic availability, language access, time off work, and trust in the health system.

That is why self-collection for HPV testing is important. It does not solve every access problem, and a positive result still needs clinical follow-up. But for some people, it removes the barrier of a pelvic exam as the first step [3].

The Next Frontier: Blood-Based Multi-Cancer Tests

Multi-cancer detection tests, sometimes called MCED tests, are blood tests designed to look for signals from more than one cancer type. The idea is exciting, especially for cancers that do not currently have routine screening tests. But this is where caution is very important.

The National Cancer Institute states that no multi-cancer detection test has been authorized by the U.S. Food and Drug Administration for cancer screening as of now, and no MCD assay has yet shown a mortality reduction in randomized clinical trials [8,9]. Some tests may still be available as laboratory-developed tests, but availability is not the same thing as proven population benefit.

Common Evidence-Based Screening Conversations

Exact screening schedules can differ slightly between organizations, and high-risk people may need earlier or more frequent screening. For average-risk adults in the United States, these are common starting points:

• Colorectal cancer: Begin screening at age 45. Options include annual FIT, stool DNA-FIT at longer intervals, CT colonography, flexible sigmoidoscopy, or colonoscopy every 10 years [10].
• Breast cancer: The USPSTF recommends mammography every other year for women ages 40 to 74 [11].
• Cervical cancer: HPV-based screening is preferred for many adults with a cervix, and self-collection is now an option for some people, depending on test availability and clinical context [2,3].
• Lung cancer: Annual low-dose CT is for selected adults ages 50 to 80 with at least a 20 pack-year smoking history who currently smoke or quit within the past 15 years [12].
• Prostate cancer: PSA screening should be an informed, shared decision for many men ages 55 to 69, not an automatic test [6].

What to Take Away

Cancer screening is powerful when it is used in the right person, at the right age, with the right follow-up plan. The goal is not to find every tiny abnormality. The goal is to prevent cancer death while avoiding unnecessary harm. Ask your clinician which screenings fit your risk, and if a test is positive, do not ignore the follow-up.

This article is for educational purposes only and should not be used as personal medical advice. Screening decisions should be made with a qualified health care professional who knows your history and risk factors.

References

1. Siegel RL et al. Cancer statistics, 2026. CA Cancer J Clin. 2026. doi:10.3322/caac.70043.
2. National Cancer Institute. Cervical Cancer Screening.
3. American Cancer Society. In-clinic and at-home HPV self-collection test. Updated 2025.
4. Doubeni CA et al. Fecal immunochemical test screening and risk of colorectal cancer death. JAMA Netw Open. 2024;7:e2423671. doi:10.1001/jamanetworkopen.2024.23671.
5. de Koning HJ et al. Reduced lung-cancer mortality with volume CT screening in a randomized trial. N Engl J Med. 2020;382:503-513. doi:10.1056/NEJMoa1911793.
6. U.S. Preventive Services Task Force. Prostate Cancer: Screening.
7. Francis DO et al. Overdiagnosis of papillary thyroid cancer. JAMA Netw Open. 2026;9:e2559852. doi:10.1001/jamanetworkopen.2025.59852.
8. National Cancer Institute. Questions and answers about multi-cancer detection tests.
9. National Cancer Institute. Cancer Screening Overview PDQ.
10. U.S. Preventive Services Task Force. Colorectal Cancer: Screening.
11. U.S. Preventive Services Task Force. Breast Cancer: Screening. 2024.
12. U.S. Preventive Services Task Force. Lung Cancer: Screening.

Featured image created using Google Gemini AI.