Non-small-cell lung cancer metastasis to unusual sites: A retrospective case series

Background: The majority of all lung cancers are non-small-cell lung cancers (NSCLCs). They usually spread to the pleura, brain, adrenal gland, lungs, liver, and bones. However, clinical data for NSCLC metastasizing to unusual sites are sparse in the literature. Objectives: We aimed to assess the pattern of metastases to unusual sites and evaluate the clinicopathological characteristics, treatment details, and outcomes of patients with NSCLC. Materials and Methods: This retrospective case series was conducted in the Department of Medical Oncology of a tertiary cancer center in Eastern India between May 2011 and December 2018. Patients with cytologically or biopsy-proven treatment-naive stage IV NSCLC were included in this audit. Sites other than the pleura, brain, adrenal gland, lung, liver, and bones were considered as unusual sites of metastases. Clinicopathological characteristics, site of metastases, treatment details, and outcomes were recorded. Data were described using descriptive statistics, survival was estimated using the Kaplan–Meier analysis, and log-rank test was used to determine survival estimates. Results: A total of 1549 patients with metastatic NSCLC were registered, of which 121 (7.8%) had metastases to unusual sites. The median age of the cohort was 72 years (range, 19–87 years), and the male:female ratio was 7:1. The most common site of unusual metastasis was the skin with soft tissue, followed by the kidney; metastasis to these sites was seen in 31 (2%) and 26 (1.6%) patients, respectively. Systemic chemotherapy was given to 67 (55.3%) patients. At a median follow-up of 11.2 months (95% confidence interval [CI], 6.8–17.5), the median progression-free survival of the cohort was 5.9 months (95% CI, 3.8–9.1). Conclusions: In