Gender-specific cut-off levels in colorectal cancer screening with fecal immunochemical test: A population-based study of colonoscopy findings and costs

Objective In the population-based Swedish regional colorectal cancer (CRC) screening program of Stockholm-Gotland using the fecal immunochemical test (FIT), gender-specific cut-off levels of fecal hemoglobin are applied, since previous studies have indicated a lower sensitivity of FIT for CRC in women. The aim was to evaluate the diagnostic yield and the screening costs overall and per detected CRC of this strategy. Methods All individuals aged 60-69 invited to screening in 2015-2017 were included. Cut-off level for positive FIT was 40 mu g/g in women and 80 mu g/g in men. Those with a positive FIT were referred to colonoscopy. The yield of CRC and screening cost for the study period were assessed and compared to cut-off levels of 80 mu g/g in both genders. Results Approximately 230,000 individuals were invited. Overall participation rates were 72% in women and 65% in men (p < 0.05). FIT was positive in 4256 individuals (2.7% in both genders). In 3758 colonoscopies, 258 (6.9%) CRCs were detected. The positive predictive value for CRC was significantly higher in men (8.3% vs. 5.8%). In 120 women with CRC, 28 (23%) had FIT < 80 mu g/g. Negative colonoscopies were more common in women (24% vs. 17%, p < 0.05). Total costs for the study period were 52,000,000SEK (approximate to 5,200,000euro), i.e. 16% higher compared to using cut-off levels of 80 mu g/g in both genders, and corresponding to a 3% increment in cost per detected CRC. Conclusion The high rate of CRC detected in women in the lowest FIT category outweighs the minor reduction in screening costs if the same cut-off level was used as for men.

Automated summary

The gender-specific cut-off levels of fecal hemoglobin in the population-based Swedish regional colorectal cancer screening program resulted in higher detection rates of CRC in women, despite a minor increase in screening costs.