Incidental detection of ground glass nodules and primary lung cancer in patients with breast cancer: prevalence and long-term follow-up on chest computed tomography.

BACKGROUND: Patients with breast cancer have a higher risk of developing lung cancer than the general population. The study aimed to evaluate the prevalence of ground glass nodule (GGN) and risk factors for GGN growth in patients with breast cancer and to evaluate the prevalence and pathologic features of lung cancer.

METHODS: We retrospectively reviewed the clinical data and chest computed tomography (CT) of 1,384 patients diagnosed with breast cancer who underwent chest CT between January 2008 and December 2022. We evaluated the prevalence of GGNs and their size changes on follow-up chest CT with volume doubling time (VDT) and identified independent risk factors associated with the growth of GGN using multivariable logistic regression analyses. Furthermore, the prevalence and pathologic features of lung cancer were also evaluated.

RESULTS: We detected persistent GGNs in 69 of 1,384 (5.0%) patients. The initial diameter of GGNs was 6.3±3.6 mm on average, with primarily (85.5%) pure GGNs. Among them, 27 (39.1%) exhibited interval growth with a median VDT of 1,006.0 days (interquartile range, 622.0-1,528.0 days) during the median 959.0 days (interquartile range, 612.0-1,645.0 days) follow-up period. Older age (P=0.026), part-solid nodules (P=0.006), and total number of GGNs (≥2) (P=0.007) were significant factors for GGN growth. Lung cancer was confirmed in 13 of 1,384 patients (0.9%), all with adenocarcinoma, including one case of minimally invasive adenocarcinoma. The cancers demonstrated a high rate of epidermal growth factor receptor (EGFR) mutation (69.2%).

CONCLUSIONS: Persistent GGNs in breast cancer patients with high-risk factors should be adequately monitored for early detection and treatment of lung cancer.