Cancer screening is often promoted as a means to save lives. The question of whether cancer screening truly saves lives is becoming increasingly relevant given the growing enthusiasm for multicancer detection blood tests (ie, liquid biopsies). It is possible in randomized clinical trials for screening to reduce deaths due to the targeted cancer without reducing deaths due to all causes. To explore the feasibility of powering studies for cancer-specific vs all-cause mortality, a series of sample size calculations was performed for selected cancers (breast, colorectal, liver, pancreas, and prostate) and for all cancers combined.
Randomized clinical trials of screening for an individual cancer typically require 100 000 or more participants to test its effect on cancer-specific mortality. Testing all-cause mortality requires trials of more than a million participants. However, the sample size requirements change markedly when considering a randomized clinical trial of screening for all cancers, as is envisioned when using multicancer detection blood tests. In this setting, the question of whether cancer screening reduces all-cause mortality can be reasonably addressed in a trial of fewer than 100 000 participants.
Conclusions and Relevance
It is not feasible to test all-cause mortality when screening for an individual cancer. However, it is feasible to test all-cause mortality for multicancer screening because cancer deaths are such a large component of deaths in general. Observational data on the effects of cancer screening are misleading. Multicancer screening would entail tremendous costs and potentially substantial harms. For these reasons, a randomized clinical trial is mandatory not only to learn if multicancer screening saves lives, but also to learn how frequently it causes harm.
Sign in to take quiz and track your certificates
JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 Credit(s)™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC
CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.
Accepted for Publication: June 17, 2023.
Published Online: August 28, 2023. doi:10.1001/jamainternmed.2023.3781
Corresponding Author: H. Gilbert Welch, MD, MPH, Center for Surgery & Public Health, One Brigham Circle, 1620 Tremont St, Ste 2-016, Boston, MA 02120 (firstname.lastname@example.org).
Author Contributions: Drs Welch and Dey had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: All authors.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical review of the manuscript for important intellectual content: Dey.
Statistical analysis: Dey.
Conflict of Interest Disclosures: Dr Welch reported royalties for 3 books. No other disclosures were reported.
Additional Contributions: We acknowledge the valuable feedback of the Center for Surgery and Public Health Early Faculty Work-in-Progress Group on Figure 1 and Table 2. No individuals were compensated for their contributions.
Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:
It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.
You currently have no searches saved.
You currently have no courses saved.