POST-POLYPECTOMY SURVEILLANCE IN THE ENGLISH BOWEL CANCER SCREENING PROGRAMME: RESULTS OF FIRST SURVEILLANCE

Aims:

The English Bowel Cancer Screening Programme (BCSP) offers biennial g-FOBt from 60 – 74 years. Post-polypectomy surveillance is offered within BCSP during the screening age range for those at “high risk” (≥5 adenomas or ≥3 at least one ≥10 mm) and “intermediate risk” (3 – 4 small adenomas or at least one ≥10 mm).

CRC screening reduces mortality. To date, robust evidence to support post-polypectomy surveillance is lacking.

Methods:

Details were extracted from the BSCP database for individuals who attended surveillance from the start of the BCSP in 2006 until January 2017. Data were analysed using Stata 14. Advanced adenoma (AA) was defined as size ≥10 mm, ≥25% villous architecture, or HGD.

Results:

Results of first surveillance were available for 43088 individuals, of whom 51.9% were IR and 48.1% HR at baseline. The most advanced neoplasia detected at first surveillance is presented in the table. First surveillance was performed at the intended time interval (12 months for HR adenomas, 3 years for IR adenomas) in ≥89% of cases.

Tab. 1:

NAA = non-advanced adenoma

Most advanced histology at first surveillance	High risk at baseline (n = 20722)	Intermediate risk at baseline (n = 22366)	Difference between HR/IR
No adenoma	39.1% (n = 8112)	56.1% (n = 12567)	p 0.000
NAA	48.0% (n = 9963)	35.3% (n = 7904)	p 0.000
AA	12.3% (n = 2545)	8.0% (n = 1798)	p 0.000
CRC	0.5% (n = 102)	0.4% (n = 97)	p 0.120

Subgroups: The subgroup with the lowest AA rate at first surveillance was those with one adenoma (≥10 mm) at baseline (n = 12397): 6.1% AA.

Conclusions:

CRC was diagnosed at first surveillance in a very small percentage of cases, reflecting the high quality baseline colonoscopy performed in the BCSP.

AA was found at first surveillance in 8.0% of those IR at baseline and in 12.3% of those HR at baseline. These results support the hypothesis that post-polypectomy surveillance may be safely delayed or discontinued in some groups, particularly those with one adenoma of ≥10 mm.