Study: Hereditary Nonpolyposis Leading Type of Colorectal Cancer

The most frequently seen type of colorectal cancer is hereditary nonpolyposis, according to a report published in the International Journal of Cancer.

Researchers from the Karolinska Institute in Sweden analyzed the risk of colorectal cancer adenocarcinoma (malignant tumors arising from a glandular organ) in related patients using data from the Swedish Family-Cancer Database of 9.8 million patients for the years 1958 to 1996.

Standardized incidence rates were calculated based on gender, age, and tumor type. Investigators found a total of 4,794 colorectal cancers in offspring and 67,925 in parents.

"This is the largest study published on familial colorectal cancer and the only one reporting specifically on adenocarcinoma," wrote the researchers. "The data suggest that hereditary nonpolyposis colorectal cancer is the largest single disease entity among colorectal cancers, probably accounting for less than 50 percent of familial colorectal cancers."

Findings from the study show that the percentage of hereditary nonpolyposis colorectal cancer could be even higher among patients diagnosed before the age of 40.

Other Sources: International Journal of Cancer