Don’t get a whole-body PET-CT or tumor marker panel if you have no symptoms

Screening completely healthy people most often yields false alarms. In one study, 86% of 1192 symptom-free individuals had at least one “abnormality” on a whole-body CT; 37% were called back for further tests, yet the vast majority of findings turned out to be benign. In large trials of ovarian cancer markers, the screened group actually had a slightly higher death rate. In some studies, 0.2%–3.25% of people underwent unnecessary surgery simply because of false positives.

A whole-body PET-CT costs roughly $7000–$10000 per scan and exposes you to ionizing radiation. Tumor marker panels cost a few hundred dollars. The real cost comes later: when an “abnormality” is found — usually a false positive — follow-up tests, biopsies, and surgeries add up both financially and physically.

The USPSTF, which evaluates preventive measures in the U.S., assigned a D rating to CA-125 testing and ultrasound screening for ovarian cancer in asymptomatic women — meaning it does not recommend them. This decision was based on the PLCO trial, which showed a 0.34% death rate from ovarian cancer in the screened group versus 0.29% in the usual care group (RR 1.18; 95% CI 0.82–1.71). No real benefit was demonstrated. The proportion of people undergoing needless surgery due to false positives ranged from 0.2%–3.25%, and only up to 15% of those developed serious complications. Another study found that 86% of 1192 symptom-free people showed at least one “abnormality” on whole-body CT; 37% were advised to undergo further tests. Most of these findings were benign. The idea that “early detection saves lives” sounds logical, but the data do not support it here.

The tumor marker portion of this recommendation is backed by randomized controlled trials. In contrast, the evidence for whole-body CT and PET-CT screening relies mainly on observational follow-ups without proper control groups, so it is rated as B. Other proven screening methods — such as those for colorectal cancer, cervical cancer, breast cancer, and low-dose chest CT for high-risk individuals — are discussed in Section 1. This recommendation does not apply to people already showing symptoms or those already diagnosed with cancer; for them, PET-CT is a diagnostic tool, not a screening measure.

US Preventive Services Task Force (2018). Screening for Ovarian Cancer: US Preventive Services Task Force Recommendation Statement. JAMA（同一份建议另有 USPSTF 官方页）. https://doi.org/10.1001/jama.2017.21926、https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/ovarian-cancer-screening；Furtado CD et al. (2005). Whole-body CT screening: spectrum of findings and recommendations in 1192 patients. Radiology. https://doi.org/10.1148/radiol.2372041741