Younger women who underwent endoscopies had a reduced risk of colorectal cancer incidence, according to findings of a prospective cohort study.
Guidelines suggesting that women initiate colorectal cancer (CRC) screening before the age of 50 years are now backed by empirical evidence, according to a study published in JAMA Oncology.1 The findings identified a greater absolute reduction in CRC risk among women who received an endoscopy before age 50 years.
Overall, compared with those receiving no endoscopy, there was a significantly lowered risk of CRC incidence among those receiving an endoscopy before age 45 years (HR, 0.37; 95% CI, 0.26-0.53) compared with 45 to 49 years (HR, 0.43; 95% CI, 0.29-0.62), 50 to 54 years (HR, 0.47; 95% CI, 0.35-0.62), or 55 years or older (HR, 0.46; 95% CI, 0.30-0.69).
Compared with women receiving an endoscopy between 50 to 54 years, the absolute reduction in the cumulative incidence of CRC was 72 per 100,000 persons for women who were screened between 45 to 49 years. Moreover, compared with no endoscopy, an endoscopy before the age 50 years was linked to a reduced risk of CRC diagnosis before the age of 55 (< 45 years: HR, 0.45; 95% CI, 0.29-0.70; 45 to 49 years: HR, 0.43; 95% CI, 0.24-0.76).
Following a growing number of patients under age 50 years receiving a diagnosis of CRC, the American Society of Clinical Oncology updated their guidelines in 2018 to recommended CRC screenings begin when a patient reached age 45 years.2 Recently, the US Preventative Services Task Force supported this recommendation with their own statement.3 However, despite these guideline updates, the benefits of endoscopies in younger populations are largely undocumented.
To that end, investigators launched a prospective cohort study which followed the data of women who enrolled in the Nurses’ Health Study II, which began in 1991, and for whom follow-data for subsequent CRC risk were available until 2017. Participating patients were between the ages of 26 to 46 years when they enrolled, allowing investigators a unique opportunity to assess the link between endoscopy age and risk.
The cohort included 111,801 women residing across 14 states. The study did not include individuals with a history of cancer (except for nonmelanoma skin cancer), inflammatory bowel disease, and colorectal polyps. These women were asked to complete baseline assessments and follow-up every 2 years to provide updates on demographics, medical history, and lifestyle factors.
Participants were asked to report if they underwent a sigmoidoscopy or colonoscopy and, if so, to say whether it was a routine screening, or because of a family history of CRC, or CRC symptoms. If patients reported having undergone polypectomy, their endoscopic and pathologic reports were reviewed.
Of note, the results showed that women who initiated an endoscopy before the age 45 years, or between ages 45 to 49 years, were more likely to have a family history of CRC, and a lower prevalence of hypertension, hypercholesterolemia, diabetes, and cancer, compared with women over the age 50 years. Moreover, women under the age 50 years were more likely to get an endoscopy because of relevant symptoms than because of their family history or as part of a routine screening.
“Our findings support guidelines from the past 4 years that recommend screening for CRC at 45 years of age and provide empirical evidence for patients, physicians, and policy makers to consider when making decisions about CRC screening in a younger population,” study authors concluded.