Our aim was to determine whether the screening of family members of familial adenomatous polyposis (FAP) patients significantly influences survival, and to gauge the extent of FAP-related causes of death.
The screening of families with FAP has been shown to be profitable in reducing colorectal cancer-related mortality, but conclusions about the screening effect on overall survival has been controversial.
This is a nationwide population-based retrospective cohort study, and the primary outcome of interest was overall mortality and survival. A total of 154 families with at least 1 clinically diagnosed FAP patient between 1963 and 2015 were included. There were altogether 194 probands and 225 call-ups. During the follow-up period, 2639 person-years with 92 deaths among probands were observed and 3634 person-years and 30 deaths among call-ups. We report crude mortality rates and standardized mortality ratios together with descriptive statistics. We compared the survival of probands and call-ups to the population by relative survival method.
The crude mortality rate among probands was 34.9 per 1000 person-years and 8.3 among call-ups. The standardized mortality ratios for call-ups was 2.47 (confidence interval, 1.69–3.46) and for probands 4.07 (confidence interval, 3.29-4.96) (P=0.014). The relative survival of probands was significantly lower than call-ups (P=0.0018), and 20-year relative survival for call-ups was 94% (88% to 100%). Over two thirds of all deaths were FAP related.
Survival of screened family members of FAP patients is comparable to the general population within 20 years after diagnosis. Therefore, participation in surveillance should not be delayed when a family member with FAP has been detected.