External validation of the colorectal cancer risk score LiFeCRC using food frequency questions in the HUNT study.

PURPOSE: To mitigate the increasing colorectal cancer (CRC) incidence globally and prevent CRC at the individual level, individual lifestyle information needs to be easily translated into CRC risk assessment. Several CRC risk prediction models exist and their clinical usefulness depends on their ease of use. Our objectives were to assess and externally validate the LiFeCRC score in our independent, unselected population and to investigate the use of simpler food frequency measurements in the score.

METHODS: Incidental colon and rectal cancer cases were compared to the general population among 78,580 individuals participating in a longitudinal health study in Norway (HUNT). Vegetable, dairy product, processed meat and sugar/confectionary consumption was scored based on food frequency. The LiFeCRC risk score was calculated for each individual.

RESULTS: Over a median of 10 years following participation in HUNT, colon cancer was diagnosed in 1355 patients and rectal cancer was diagnosed in 473 patients. The LiFeCRC score using food frequencies demonstrated good discrimination in CRC overall (AUC 0.77) and in sex-specific models (AUC men 0.76 and women 0.77) in this population also including individuals ≥ 70 years and patients with diabetes. It performed somewhat better in colon (AUC 0.80) than in rectal cancer (AUC 0.72) and worked best for female colon cancer (AUC 0.81).

CONCLUSION: Readily available clinical variables and food frequency questions in a modified LiFeCRC score can identify patients at risk of CRC and may improve primary prevention by motivating to lifestyle change or participation in the CRC screening programme.