Dr Luca Reggiani-Bonetti and colleagues from Italy described the incidence trend of malignant polyp of large bowel over a 25-year period in the District of Modena, and assessed the effect of an organized colorectal cancer screening program.
Through the data of a specialized colorectal cancer Registry, the team evaluated the clinical and pathological features of the polyps.
Trend analysis was assessed with the Joinpoint Regression Program.
A total of 172 patients with malignant polyps were diagnosed throughout the study.
The team found that their overall frequency during the registration period increased from zero cases in the initial years to 57 cases in the past 3 years.
|There was an increase of incidence ranging between 39%, and 7%|
|Scandanavian Journal of Gastroenterology|
Crude incidence rate passed from 0.4 in 1986–89 to 10 in 2006.
Joinpoint trend analysis of crude rates showed a significant increase of incidence during the study period, with percent of annual variation ranging between 39%, and 7%.
The research team noted that during the screening period there was a significant increase of sessile polyps, while other clinical and morphological features, including the number of low- and high-risk malignant polyps, remained unchanged.
The surgery tended to raise both in low- and high-risk subgroups.
Dr Reggiani-Bonetti's team concludes, "The incidence of malignant polyps increased significantly from the initial to the most recent periods of colorectal cancer registration."
"Screening was associated with changes in gross morphology of polyps and with an increased use of the surgery after endoscopic polypectomy."