Calculation of Stop Ages for Colorectal Cancer Screening Based on Comorbidities and Screening History

Abstract

Background & aims: Routine screening for colorectal cancer typically is recommended until age 74 years. Although it has been proposed that a screening stop age could be determined based on sex and comorbidity, less is known about the impact of screening history. We investigated the effects of screening history on the selection of an optimal age to stop screening.

Methods: We used the Microsimulation Screening Analysis-Colon model to estimate the harms and benefits of screening with biennial fecal immunochemical tests by sex, comorbidity status, and screening history. The optimal screening stop age was determined based on the incremental number needed for 1 additional life-year per 1000 screened individuals compared with the threshold provided by stopping screening at 76 years in the average-health population with a perfect screening history (attended all required screening, diagnostic, and follow-up tests) to biennial fecal immunochemical testing from age 50 years.

Results: For persons age 76 years, 157 women and 108 men with a perfect screening history would need to be screened to gain 1 life-year per 1000 screened individuals. Previously unscreened women with no comorbid conditions and no history of screening could undergo an initial screening through 90 years, whereas unscreened men could undergo initial screening through 88 years, before this balance is reached. As screening adherence improved or as comorbidities increased, the optimal age to stop screening decreased to a point that, regardless of sex, individuals with severe comorbidities and a perfect screening history should stop screening at age 66 years or younger.

Conclusions: Based on the harm-benefit balance, the optimal stop age for colorectal cancer screening ranges from 66 years for unhealthy individuals with a perfect screening history to 90 years for healthy individuals without prior screening. These findings can be used to assist patients and clinicians in making decisions about screening participation.

Keywords: Colon Cancer; Detection; Patient Outcomes; Precision Medicine.

Figure 1:. Number needed to screen per life year gained by age and comorbidity level, for females (a, c) and males (b, d) with perfect prior FIT screening (a, b) and no prior screening (c, d).

A. Females, under the assumption of perfect prior screening with FIT B. Males, under the assumption of perfect prior screening with FIT C. Females, under the assumption of no prior screening with FIT D. Males, under the assumption of no prior screening with FIT Abbreviations: NNS/LYG = number needed to screen to gain one life year Each line represents the number needed to screen per life year gained over the ages 66 to 90 for each level of comorbidity. The solid horizontal line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 74 (acceptable threshold). The dashed line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 76 (upper threshold). The recommended CRC screening stop-age is defined by this range. Where two ages fall within the threshold range, the lowest of the two values is selected. Where no values fall within the threshold range, the age closest to the lowest level is selected. The vertical dashed lines indicate the age for each comorbidity group where screening provides a balance of harms and benefits similar to those aged 74 with average health.

Figure 1:. Number needed to screen per life year gained by age and comorbidity level, for females (a, c) and males (b, d) with perfect prior FIT screening (a, b) and no prior screening (c, d).

A. Females, under the assumption of perfect prior screening with FIT B. Males, under the assumption of perfect prior screening with FIT C. Females, under the assumption of no prior screening with FIT D. Males, under the assumption of no prior screening with FIT Abbreviations: NNS/LYG = number needed to screen to gain one life year Each line represents the number needed to screen per life year gained over the ages 66 to 90 for each level of comorbidity. The solid horizontal line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 74 (acceptable threshold). The dashed line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 76 (upper threshold). The recommended CRC screening stop-age is defined by this range. Where two ages fall within the threshold range, the lowest of the two values is selected. Where no values fall within the threshold range, the age closest to the lowest level is selected. The vertical dashed lines indicate the age for each comorbidity group where screening provides a balance of harms and benefits similar to those aged 74 with average health.

Figure 1:. Number needed to screen per life year gained by age and comorbidity level, for females (a, c) and males (b, d) with perfect prior FIT screening (a, b) and no prior screening (c, d).

A. Females, under the assumption of perfect prior screening with FIT B. Males, under the assumption of perfect prior screening with FIT C. Females, under the assumption of no prior screening with FIT D. Males, under the assumption of no prior screening with FIT Abbreviations: NNS/LYG = number needed to screen to gain one life year Each line represents the number needed to screen per life year gained over the ages 66 to 90 for each level of comorbidity. The solid horizontal line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 74 (acceptable threshold). The dashed line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 76 (upper threshold). The recommended CRC screening stop-age is defined by this range. Where two ages fall within the threshold range, the lowest of the two values is selected. Where no values fall within the threshold range, the age closest to the lowest level is selected. The vertical dashed lines indicate the age for each comorbidity group where screening provides a balance of harms and benefits similar to those aged 74 with average health.

Figure 1:. Number needed to screen per life year gained by age and comorbidity level, for females (a, c) and males (b, d) with perfect prior FIT screening (a, b) and no prior screening (c, d).

A. Females, under the assumption of perfect prior screening with FIT B. Males, under the assumption of perfect prior screening with FIT C. Females, under the assumption of no prior screening with FIT D. Males, under the assumption of no prior screening with FIT Abbreviations: NNS/LYG = number needed to screen to gain one life year Each line represents the number needed to screen per life year gained over the ages 66 to 90 for each level of comorbidity. The solid horizontal line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 74 (acceptable threshold). The dashed line represents the threshold for the number needed to screen per life year gained for screening in the average health population until the age of 76 (upper threshold). The recommended CRC screening stop-age is defined by this range. Where two ages fall within the threshold range, the lowest of the two values is selected. Where no values fall within the threshold range, the age closest to the lowest level is selected. The vertical dashed lines indicate the age for each comorbidity group where screening provides a balance of harms and benefits similar to those aged 74 with average health.