Association Between ER/PR-Positive Breast Tumors and Digestive Cancers

Background/Objectives: Breast cancer is the most commonly diagnosed malignancy among women, with hormone receptor-positive tumors representing the majority of cases. Increasing survival rates have shifted attention toward long-term complications, including the risk of secondary malignancies. Emerging evidence suggests a potential association between breast cancer and gastrointestinal (GI) neoplasia. This study aimed to evaluate the role of colonoscopic and upper gastrointestinal endoscopic monitoring in patients with ER/PR-positive breast cancer and to assess its potential value in the early detection of digestive lesions. Methods: We conducted a prospective observational study including 186 female patients with histologically confirmed ER/PR-positive breast cancer. A total of 95 patients underwent colonoscopy, and 91 patients underwent upper gastrointestinal endoscopy. Clinical, demographic, and risk factor data were collected. A structured questionnaire was used to assess gastrointestinal symptoms. Endoscopic findings, lesion characteristics, and histopathological results were recorded. Bowel preparation quality was assessed using the Boston Bowel Preparation Scale. Results: Colonoscopy identified polyps and other lesions, with the majority located in the rectum and descending colon. A total of 12 biopsies were performed, revealing 1 malignant lesion, 2 borderline lesions, and the remainder benign. Upper gastrointestinal endoscopy showed gastritis as the most frequent finding, followed by gastric ulcers and polyps, while most patients had normal endoscopic results. Overall, 72% of patients presented at least one risk factor for digestive malignancy. Following treatment, most patients reported improvement in gastrointestinal symptoms. Conclusions: Patients with ER/PR-positive breast cancer may present a higher prevalence of gastrointestinal lesions, potentially related to shared risk factors and the systemic effects of endocrine therapy. Targeted, symptom-oriented endoscopic evaluation may facilitate early detection of premalignant and malignant digestive conditions. A multidisciplinary, risk-adapted surveillance approach should be considered to improve patient outcomes. Further large-scale studies are required to establish evidence-based screening strategies in this population.