Risk of colon adenoma in patients with breast cancer.

Abstract

1541 Background: In our clinical practice at a tertiary cancer center, we have observed increased adenoma detection rate (ADR) in patients with breast cancer. Here, we describe ADR in patients with breast cancer to define the appropriate timing to initiate colonoscopy screening in these patients. Methods: We conducted a retrospective study of patients with breast cancer who underwent a colonoscopy after their diagnosis of breast cancer between 2000 and 2017. A control group ( n = 3295) comprised patients without any type of cancer who underwent their first screening colonoscopy between 2008 and 2017 was used in the logistic regression. Results: Of the 62,820 patients who had a diagnosis of breast cancer, 3304 were included. The mean age was 59 years. Regarding ADR, 1803 patients (55%) had adenomas. High-grade dysplasia was evident in 28% of polyps and invasive adenocarcinoma in 172 (5%). The median time from breast cancer diagnosis to adenoma detection was 3 years (IQR 1-6). The ADR was 21% in patients younger than 40 years ( n=63), 39% in patients between 40 and 50 years ( n=314), 54% in patients between 50 and 60 years ( n=1420), and 60% in patients older than 60 years ( n=1507). ADR in patients younger than 50 years of age who do not have a family history of colorectal cancer or a body mass index (BMI) higher than 30 kg/m2 was 26%. A subsequent colonoscopy was performed in 831 patients who had colonic adenoma in the initial colonoscopy. The ADR was 40% in patients who had a repeat colonoscopy within 3 years, 50% within 3-5 years, and 53% > 5 years. Multivariate logistic regression analyses revealed an increased risk of colon adenoma with older age, male sex, higher BMI, and personal history of breast cancer ( P<0.05). Conclusions: In patients with breast cancer, ADR was higher than that of patients without history of cancer. Notably, breast cancer was an independent risk factor for colon adenoma. In patients who are younger than 40 years of age, screening colonoscopy should be considered within five years of breast cancer diagnosis. Multivariate logistic regression: risk factors of adenoma. [Table: see text]