Cancer screenings have been viewed as a life-saving early detection and prevention strategy against the disease.
Sigmoidoscopy Leads in Life ExpectancyAfter comparing six tests commonly used to detect breast, lung, prostate, and colon cancer, only sigmoidoscopy—a medical procedure used to look for abnormalities inside the colon—showed a significant impact on life gains of 110 days.
The study, published on Aug. 28 in the Journal of the American Medical Association (JAMA) Internal Medicine, pooled results from 18 randomized clinical trials and included more than nine years of follow-up data.
There was no significant difference following mammographies, colonoscopies, fecal blood occult testing, computed tomography (CT scans), and prostate-specific antigen (PSA) testing compared to patients who had none of these screenings.
"While fecal testing and mammography screening did not prolong life ... an extension of 37 days was noted for prostate cancer screening with prostate-specific antigen testing and 107 days with lung cancer screening using computed tomography, but estimates are uncertain," the study authors wrote.
Risks Versus BenefitsSome individuals do live longer as a result of screenings. The earlier the detection, the better the outcome regarding survival and successful treatments following diagnosis without harm or complications, the study authors wrote.
At the same time, other individuals aren't as fortunate, with some living for a shorter time because of the dangers associated with screenings. A colonoscopy can tear the colon, and invasive prostatectomies can induce heart attacks, according to the authors.
While these results may suggest that claims that cancer screenings save lives are unsubstantiated, the authors don't advocate against them in the paper. Tests in which the benefits outweigh the risks may be worth it. At the same time, patients must know that their doctors will disclose potential harms without bias. This requires that medical professionals offer full transparency about tackling the disease and be willing to consider alternatives.
The authors also pointed out that they aren't advocating against screenings but instead are trying to raise awareness so that patients and practitioners can have well-informed discussions.
Risks of ScreeningsThe NCI lists several possible harms associated with screenings, which include:
- Bruising, discomfort, or colon perforation when undergoing colonoscopy or sigmoidoscopy.
- Radiation exposure that can damage healthy cells.
- False-negative results, which could lead people to skip follow-up appointments despite ongoing symptoms.
- False positives resulting in anxiety and additional unnecessary testing.
- Psychological harm, such as excessive stress about preparing for the screening, waiting for results, and worrying about follow-up tests.
- Overdiagnosis of small, slow-growing cancers that would never cause any symptoms.
Benefits of ScreeningsIn a 2020 study published in Radiology Imaging Cancer that involved more than two decades of evidence, researchers concluded that CT scan screenings can prevent a substantial number of lung cancer-related deaths with low clinical risk.
Cancer StatisticsThe American Cancer Society (pdf) estimates that roughly 2 million people will be diagnosed with cancer in the United States in 2023. Approximately 297,790 women and 2,800 men will be diagnosed with breast cancer, making breast cancer the most common cancer diagnosis. Prostate cancer is the leading cancer among men and the second most commonly diagnosed overall, with 288,300 expected cases.
- Lung cancer.
- Colorectal cancer.
- Skin melanoma.
- Bladder cancer.
- Kidney and renal pelvic cancer.
- Non-Hodgkin lymphoma.
- Uterine cancer.
- Pancreatic cancer.
- Thyroid cancer.