Patients who waited 10 months or longer for follow-up colonoscopy after a positive fecal immunochemical test (FIT) experienced a higher risk of colorectal cancer and an increased rate of advanced-stage disease on diagnosis than did patients who underwent follow-up colonoscopy within 8 to 30 days. As these results are correlative, additional research could assess the nature of this relationship.

FIT, commonly used to screen for colorectal cancer, requires a follow-up colonoscopy for positive test results. The time between FIT and colonoscopy, however, can vary, with longer intervals potentially allowing disease progression.

This retrospective cohort study assessed data from patients in Kaiser Permanente Northern and Southern California between January 2010 and December 2014. Patients (N = 70,124) were aged 50 to 70 years, had a positive result on FIT, and underwent a follow-up colonoscopy.

A total of 2191 diagnoses of colorectal cancer were made, with 601 cases being advanced-stage disease.

No differences in risk of any colorectal cancer or of advanced-stage disease occurred when researchers compared colonoscopy follow-up groups of 8 to 30 days (n = 27,176), 2 months (n = 24,644), 3 months (n = 8666), 4 to 6 months (n = 5251), or 7 to 9 months (n = 1335).

Risks for colorectal cancer and advanced-stage disease were significantly higher for follow-up colonoscopy at 10 to 12 months and longer than 12 months.

These results suggest a need to undergo a follow-up colonoscopy soon after positive FIT results.

Reference

1. Corley DA, Jensen CD, Quinn VP, et al. Association between time to colonoscopy after a positive fecal test result and risk of colorectal cancer and cancer stage at diagnosis [published online April 25, 2017]. JAMA. doi: 10.1001/jama.2017.3634