Effects of Screening Compliance on Long-term Reductions in All-Cause and Colorectal Cancer Mortality

Aasma Shaukat, Lasse Kaalby, Gunnar Baatrup, Ole Kronborg, Sue Duval, Michael Shyne, Jack S. Mandel, Timothy R. Church

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Background & Aims: Randomized trials have shown that biennial fecal occult blood test (FOBT) screening reduces mortality from colorectal cancer (CRC), but not overall mortality. Differences in benefit for men vs women, and by age, are unknown. We sought to evaluate long-term reduction in all-cause and CRC-specific mortality in men and women who comply with offered screening, and in different age groups, using individual participant data from 2 large randomized trials of biennial FOBT screening, compared with an intention to treat analysis. Methods: We updated the CRC and all-cause mortality from the Danish CRC screening trial (n = 61,933) through 30 years of follow up and pooled individual participant data with individual 30-year follow-up data from the Minnesota Colon Cancer Control trial (n = 46,551). We compared the biennial screening groups to usual care (controls) in individuals 50–80 years old using Kaplan Meier estimates of relative risks and risk differences, adjusted for study differences in age, sex, and compliance. Results: Through 30 years of follow up, there were 33,478 (71.9%) and 33,479 (72.2%) total deaths and 1023 (2.2%) and 1146 (2.5%) CRC deaths in the biennial screening (n = 46,553) and control groups (n = 46,358), respectively. Among compliers, biennial FOBT screening significantly reduced CRC mortality by 16% (relative risk [RR], 0.84; 95% CI, 0.74–0.96) and all-cause mortality by 2% (RR, 0.98; 95% CI, 0.97–0.99). Among compliers, the reduction in CRC mortality was larger for men (RR, 0.75; 95% CI, 0.62–0.90) than women (RR, 0.91; 95% CI, 0.75–1.09). The largest reduction in CRC mortality was in compliant men 60–69 years old (RR, 0.59; 95% CI, 0.42–0.81) and women 70 years and older (RR, 0.53; 95% CI, 0.30–0.94). Conclusions: Long-term CRC mortality outcomes of screening among compliers using biennial FOBT are sustained, with a statistically significant reduction in all-cause mortality. The reduction in CRC mortality is greater in men than women—the benefit in women lags that of men by about 10 years.

Original languageEnglish (US)
Pages (from-to)967-975.e2
JournalClinical Gastroenterology and Hepatology
Issue number5
StatePublished - May 1 2021

Bibliographical note

Publisher Copyright:
© 2021 AGA Institute


  • Colon Cancer
  • Compliance
  • Early Detection
  • Survival


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