Incidence and natural course of CT-detected pulmonary ground-glass nodules in Chinese women with breast cancer: a retrospective, single-center, long-term follow-up study in 4682 consecutive patients.

Background Increased use of thin-section computed tomography (CT) scans has revealed that small lung nodules, termed ground-glass nodules, are frequent in primary breast cancer patients and are associated with pre-invasive or invasive pulmonary adenocarcinomas. However, little is known of the incidence and fate of ground-glass nodules. Purpose To elucidate the incidence and natural course of CT-detected pulmonary ground-glass nodules in Chinese women with breast cancer. Material and Methods We retrospectively reviewed data from female breast cancer patients who underwent lung CT scans and who were followed for >= 3 months after the initial scan to identify the incidence of ground-glass nodules and any changes in them during the follow-up period. Results Between January 2008 and April 2018, 693 out of 4682 breast cancer patients (14.8%) had persistent lung ground-glass nodules as detected by CT scan. The median age was 52 years (interquartile range [IQR] = 45-62 years). Median nodule size was 4.9 mm in diameter on initial CT scan. Frequency of growth was 7.5% (52/693 patients). Median volume doubling time was 1092 days (IQR = 719-1808 days) for 39 growing in size nodules. Initial nodule size, nodule type, and follow-up period were independent predictors of nodule growth. Conclusion Most pulmonary ground-glass nodules in breast cancer patients were stable during long-term follow-up; most growing nodules had an indolent clinical course, suggesting that nodules should be monitored until growth is detected. This information is clinically relevant for accurate diagnosis of cancer stage and for appropriate treatment plans for patients with lung ground-glass nodules.