A matched cohort study found that patients with any polyps have a greater likelihood of having colorectal cancer, and those with sessile serrated polyps, tubulovillous adenomas, and villous adenomas are more likely to die from the disease.
Researchers identified patients in Sweden aged 18 years or older with a first diagnosis of colorectal polyps between 1993 and 2016 in the nationwide gastrointestinal ESPRESSO histopathology cohort. Every polyp case was matched by birth year, age, sex, biopsy year, and county of residence to up to five patients identified in the Total Population Register. Patients who were diagnosed with colorectal cancer before or within the first six months of the index polyp were excluded. Polyps were categorized as hyperplastic polyps, sessile serrated polyps, tubular adenomas, tubulovillous adenomas, and villous adenomas. The Swedish Cancer Registry was used to identify cases of colorectal cancer, and the Cause of Death register was used for cause of death data. Cumulative colorectal cancer incidence and mortality risks at three, five, 10, and 15 years were calculated.
The study was published in The Lancet Gastroenterology & Hepatology.
Final analysis included 178,377 patients with colorectal polyps and 864,831 matched reference patients. The mean age at diagnosis was 58.6 years for hyperplastic polyps, 59.7 years for sessile serrated polyps, 63.9 years for tubular adenomas, 67.1 years for tubulovillous adenomas, and 68.9 years for villous adenomas. Over a median 6.6 years of follow-up, 4,278 incident colorectal cancers and 1,269 colorectal cancer-related deaths were recorded in patients with a polyp, and 14,350 incident colorectal cancers and 5,242 related deaths were recorded in the reference group. The 10-year cumulative colorectal cancer incidence was 1.6% for hyperplastic polyps, 2.5% for sessile serrated polyps, 2.7% for tubular adenomas, 5.1% for tubulovillous adenomas, and 8.6% for villous adenomas; for the reference patients, the rate was 2.1%. Patients with any polyps, compared to the reference group, were more likely to develop colorectal cancer; multivariable hazard ratios (HRs) were 1.11 for hyperplastic polyps, 1.77 for sessile serrated polyps, 1.41 for tubular adenomas, 2.56 for tubulovillous adenomas, and 3.82 for villous adenomas. Sessile serrated polyps, tubulovillous adenomas, and villous adenomas were all correlated with a higher risk for colorectal cancer mortality, with HRs of 1.74, 1.95, and 3.45, respectively; however, this association was not observed for hyperplastic polyps (HR=0.90) or tubular adenomas (HR=0.97).
“In a largely screening-naive population, compared with individuals from the general population, patients with any polyps had a higher colorectal cancer incidence, and those with sessile serrated polyps, tubulovillous adenomas, and villous adenomas had a higher colorectal cancer mortality,” summarized the researchers.