1359PD_PR - Incidence of colorectal neoplasia in a high risk population screened for colorectal cancer. Result of 5 consecutives mass screening campaigns in a...

Date 27 September 2014
Event ESMO 2014
Session Challenges in cancer screening and care: dealing with the issues of access and cost of therapy
Topics Cancer Aetiology, Epidemiology, Prevention
Colon Cancer
Rectal Cancer
Presenter Sylvain Manfredi
Citation Annals of Oncology (2014) 25 (5): 1-41. 10.1093/annonc/mdu438
Authors S. Manfredi1, J.F. Bretagne1, G. Durand2, C. Piette2, G. Mallard2, J. Faivre3
  • 1Disease Of The Digestive Tract, CHU Pontchaillou, 35000 - Rennes/FR
  • 2Adeci 35, adeci 35, 35000 - rennes/FR
  • 3Gastroenterology, CHU dijon, 21000 - dijon/FR




Colorectal cancer mass screening with FOBT is implemented to screen average risk population aged 50–74 years. Some colorectal neoplasia history is revealed by the pre-screening procedure. Patients were so excluded from FOBT screening and then a screening colonoscopy was offered. We studied this population at high risk colorectal neoplasia naïve for previous colorectal exploration, from 5 consecutive colorectal cancer screening campaigns.


Variables: age, campaign, source of exclusion (general practitioner (GP) or gastroenterologist), colonoscopy completion rate, positive predictive value (PPV) of neoplasia (cancer, advanced adenoma, adenoma).


1179 patients studied (0.1-0.3% of the target population), mean age 59.7 years. Colonoscopy performed for 889 patients, complete in 97.5% of cases. In 68.1% of cases the history was revealed by the GP. Colonoscopy was achieved in 70% of cases when history was detected by the GP and in 87% when detected by the gastroenterologist. 253 Colorectal neoplasias were diagnosed; 35 cancers (TNM stage 0-1: 74%, TNM stage 2: 9%, TNM stage 3: 14%, TNM stage 4: 3%), 14 resected endoscopically; one or more adenomas diagnosed in 219 patients and a total of 347 adenomas resected, endoscopically in 98.5% of cases. The average number of adenoma per patient was 2.1 (1 to 50) and the average size was 7.2 mm (1 to 75). Size was ≥10 mm for 38% of cases, 38.3% had a villous component and 7.9% were high grade dysplasia. A total of 209 advanced adenomas (size ≥ 10 mm and/or villous component and/or high grade dysplasia and/or number ≥ 3) were diagnosed in 122 patients. PPV of cancer was 3.9%, PPV of advanced adenoma was 12.9%, and PPV of adenoma was 25%.


In this population with a history of colorectal neoplasia revealed by the mass screening campaign, the rate of participation in screening is very high (75.5%). The PPV of neoplasia is lower than in the average risk population selected by a positive FOBT (PPV of cancer range 7.5 to 10%, PPV of advanced adenoma range 15 to 27% and PPV of adenoma range 32 to 37% in our administrative area). This population might probably also benefit from screening with FOBT.


All authors have declared no conflicts of interest.