6-month delay in colonoscopy after positive colorectal cancer test increases risk for advanced cancer
SAN DIEGO — After a positive colorectal cancer test, a 6-month delay in colonoscopy increased the risk for finding an advanced stage of cancer, according to a study presented at Digestive Disease Week 2016.
“The thought is that longer intervals may result in one of two things: Polyps that advance to cancer or cancer that increases its stage,” Douglas Corley, MD, PhD, MPH, research scientist at the Kaiser Permanente Northern California Division of Research, said during a presentation. “Our goal was to be able to evaluate the associations between the time from positive [fecal immunochemical test (FIT)] to colonoscopy and the risk of colorectal cancer outcomes.”
FIT screens are commonly used to test for colorectal cancer (CRC) and positive tests require a follow-up colonoscopy, the researchers wrote. However, there is no guideline for how long to await the colonoscopy. In addition, there are little data about the consequences of waiting.
To evaluate the time to colonoscopy and the risk for CRC-related outcomes, the researchers performed a retrospective cohort study of 82,887 patients aged between 50 and 75 years who received a positive FIT result between 2010 and 2013 at Kaiser Permanente Northern California and Southern California. The researchers organized the follow-up times into six groups: 8 to 30 days, 31 to 60 days, 61 to 90 days, 91 to 180 days, 181 to 364 days and greater than 365 days. They investigated the association between follow-up time and risk for CRC while adjusting for sex, age, BMI, ethnicity, Charlson comorbidity score, Kaiser Permanente location, FIT screening year and previous FIT screening.
Eighty-two percent of patients completed a colonoscopy within a median wait time of 37 days. More specifically, 64.1% received a colonoscopy within 60 days and 83.4% received one within 12 months. Compared with patients with a follow-up fewer than 30 days, patients receiving a colonoscopy between 6 and 12 months were significantly more likely to be diagnosed with CRC (adjusted OR [aOR] = 1.29; 95% CI, 1.02-1.62) and stage II CRC (aOR = 1.98; 95% CI, 1.28-3.06). Also compared with these patients, patients with a follow-up greater than 12 months were significantly more likely to be diagnosed with stage III CRC (aOR = 2.64; 95% CI, 1.87-3.72) and stage IV CRC (aOR = 4.27; 95% CI, 2.48-7.35).
The risks for CRC were highest for those aged between 61 and 75 years, the researchers wrote. – by Will Offit
Jensen CD, et al. Abstract #175. Presented at: Digestive Disease Week; May 21-24, 2016; San Diego.
Disclosure: Corley reports receiving fees from Pfizer.