Table 1 Causes of cancer and potential reduction in cancer burden through preventive measures. N/A, not applicable.
Cause*Percentage of cancer causedNumber of deaths in United StatesMagnitude of possible reduction (%)Period of time (years)Evidence example
Smoking33188,7447510–20Comparison of lung cancer mortality by state (Fig. 1)
Overweight and obesity20114,390502–20Bariatric surgery and sustained changes in weight and markers (62)
Diet528,600505–20Folate and colorectal cancer (63)
Lack of exercise528,600855–20Adolescent physical activity (18)
Occupation528,6005020–40Asbestos workplace regulation (10)
Viruses528,60010020–40Liver cancer reduction by vaccine (22)
Family history528,600502–10Bilateral oophorectomy for BRCA1/2 (34); aspirin trial for Lynch syndrome (11)
Alcohol317,200505–20Regulation (64)
UV and ionizing radiation211,400505–40Reduced medical exposures (65)
Prescription drugs15,720502–10Hormone therapy–related drop in breast cancer (66)
Reproductive factors317,2000N/AN/A
Pollution211,4000N/AN/A
Total potential reduction = 54.5%

*Adapted from Wolin et al. (67).

†U.S. death estimates from the American Cancer Society (68).

‡Defined as sum (percentage caused by modifiable exposure × magnitude of reduction).