Personalizing age of cancer screening cessation based on comorbid conditions: model estimates of harms and benefits

Abstract

Background: Harms and benefits of cancer screening depend on age and comorbid conditions, but reliable estimates are lacking.

Objective: To estimate the harms and benefits of cancer screening by age and comorbid conditions to inform decisions about screening cessation.

Design: Collaborative modeling with 7 cancer simulation models and common data on average and comorbid condition level-specific life expectancy.

Setting: U.S. population.

Patients: U.S. cohorts aged 66 to 90 years in 2010 with average health or 1 of 4 comorbid condition levels: none, mild, moderate, or severe.

Intervention: Mammography, prostate-specific antigen testing, or fecal immunochemical testing.

Measurements: Lifetime cancer deaths prevented and life-years gained (benefits); false-positive test results and overdiagnosed cancer cases (harms). For each comorbid condition level, the age at which harms and benefits of screening were similar to that for persons with average health having screening at age 74 years.

Results: Screening 1000 women with average life expectancy at age 74 years for breast cancer resulted in 79 to 96 (range across models) false-positive results, 0.5 to 0.8 overdiagnosed cancer cases, and 0.7 to 0.9 prevented cancer deaths. Although absolute numbers of harms and benefits differed across cancer sites, the ages at which to cease screening were consistent across models and cancer sites. For persons with no, mild, moderate, and severe comorbid conditions, screening until ages 76, 74, 72, and 66 years, respectively, resulted in harms and benefits similar to average-health persons.

Limitation: Comorbid conditions influenced only life expectancy.

Conclusion: Comorbid conditions are an important determinant of harms and benefits of screening. Estimates of screening benefits and harms by comorbid condition can inform discussions between providers and patients about personalizing screening cessation decisions.

Primary funding source: National Cancer Institute and Centers for Disease Control and Prevention.

Figure 1

Number needed to screen per life-year gained (NNS/LYG) for screening at the plotted age by comorbidity level. The horizontal dashed line represents the NNS/LYG for screening the average-health population until age 76 (75 for colorectal cancer). The vertical dashed lines indicate the age for each comorbidity group at which screening provided similar harms and benefits as screening at age 74 in the average-health population (oldest age for which the NNS/LYG falls under the vertical dotted line). Panels show number needed to screen to gain 1 life-year (NNS/LYG) projected by MISCAN-Fadia and Model G-E model for breast cancer; by MISCAN-Prostate and FHCRC model for prostate cancer; and by MISCAN-Colon, CRC-SPIN, and SimCRC for colorectal cancer.

Figure 2

Age at which harms and benefits of screening were similar to that for individuals with average health undergoing screening at age 74. The grey bars represent the median age while the uncertainty bars represent the range across all models and cancer sites. For no comorbidity, the lowest cessation age across models and cancer sites coincides with the median age (see Figure 1 and Appendix Table 2).