COLORECTAL CANCER RISK AND ADENOMA DETECTION RATE IN IMMUNOCHEMICAL FAECAL TEST SCREENING PROGRAMS

Aims Colorectal Cancer (CRC) screening programs based on Faecal Immunochemical Test (FIT) represent the standard of care for population-based intervention. Its benefit depends on identification of neoplasia at colonoscopy in FIT+subjects. Thus, its quality as measured by Adenoma Detection Rate (ADR) may affect its outcomes.

Methods We performed a retrospective cohort study on patients undergoing colonoscopy after FIT+within a CRC-screening program between 2003 and 2017 in Italy. We recovered data on CRC diagnosed and CRC deaths observed between 6 months and 10 years after colonoscopy. Risk of interval-CRC incidence and mortality was assessed according to endoscopists’ ADR and advanced-ADR quintiles. Estimation of hazard ratio (HR) was adjusted for sex and age.

Results Overall, we included 68,604 colonoscopies performed by 133 endoscopists. After 295,081 person/years of follow up, 289 interval-CRCs were identified, resulting in 42 CRC-related deaths. Mean ADR was 48% (range 8-87%). When subdividing endoscopists by ADR quintile, unadjusted risk of interval-CRC from lowest to highest was 11.4, 9.7, 7.6, 11.4 and 9.5 per 10,000 person/years of follow up. No difference in CRC incidence and mortality between endoscopists in the lowest ADR quintile and the highest (aHR for CRC incidence/mortality: 0.80 [95%CI 0.52-1.23]/0.56 [95%CI 0.19-1.62]). Similar findings were observed using advanced ADR quintiles (aHR for CRC incidence/mortality: 1.03 [95%CI 0.67-1.57]/1.49 [95%CI 0.55-4.06]).

Table 1

	CRC Incidence	CRC Mortality
Sex
Female	1.00	–0.95	1.00	–0.63
Male	1.20	– 1.53	1.18	– 2.20
Age (years)
50-59	1.00	–1.39	1.00	–0.75
60-70	1.77	– 2.27	1.40	– 2.60
ADR quintile
1 st	1.00	–0.51 – 1.14	1.00	–0.12 – 1.19
2 nd	0.76	0.44 – 1.00	0.39	0.27 – 1.79
3 rd	0.66	0.60 – 1.34	0.70	0.36 – 2.14
4 th	0.90	0.52 – 1.23	0.87	0.19 – 1.62
5 th	0.80		0.56
AADR quintile
1 st	1.00	–0.75 – 1.71	1.00	–0.29 – 2.83
2 nd	1.13	0.57 – 1.29	0.91	0.19 – 1.88
3 rd	0.86	0.81 – 1.83	0.60	0.61 – 4.31
4 th	1.22	0.67 – 1.57	1.63	0.54 – 4.05
5 th	1.03		1.49

Fig. 1

Conclusions The lack of association between ADR and CRC incidence and mortality, as well as the low risk of interval CRC due to incomplete resection, supports the incorporation of colonoscopy resources within a programmatic intervention.

Publication History

Article published online:
14 April 2022