Pooled analysis of studies of pulmonary nodules in breast cancer patients

Pulmonary nodules are frequently detected during staging or follow-up in breast cancer, yet their prevalence, the use of invasive diagnostic intervention, and the pathologic spectrum are uncertain. Reseachers at Chongqing Medical University (Chongqing, China) carried out a pooled analysis of observational studies of pulmonary nodules in patients with breast cancer published up to 16 October 2025. Twenty-seven studies were included. Eleven CT-only studies (n=13,363) yielded a pooled pulmonary nodule prevalence of 13.1% (95% CI 5.6-27.4); prevalence was 9.8% (5.0-18.3) at initial staging and 12.5% (0.1-96.2) during follow-up. Across seven studies involving 3,163 patients with nodules, the pooled invasive diagnostic intervention portion was 15.3% (95% CI 6.6-31.6). Among pathologically confirmed nodules (17 studies,n=1,223), pooled proportions were 17.5% benign (95% CI 13.0-23.1), 46.3% primary lung cancer (34.9-58.1), and 37.6% metastatic breast cancer (29.7-46.2). The authors conclude that pulmonary nodules were detected in about 13% of patients with breast cancer undergoing CT, and a minority of patients with nodules underwent invasive diagnostic intervention. Among pathologically confirmed nodules, primary lung cancer and metastatic breast cancer were both common, with benign disease also contributing substantially. Pulmonary nodules in patients with breast cancer should therefore not be presumed metastatic; clinical assessment should consider alternative diagnoses.