BACKGROUND

Adrenal metastasectomy is associated with increased survival in non-small cell lung cancer (NSCLC) with isolated adrenal metastases. Although clinical use of adrenal metastasectomy has expanded, indications remain poorly defined. The aim of this study was to evaluate the clinical benefit of adrenal metastasectomy for all lung cancer subtypes.

PATIENTS AND METHODS

We performed a retrospective cohort study of patients who underwent adrenal metastasectomy for metastatic lung cancer at six institutions between 2001 and 2015. The primary outcomes were disease-free survival (DFS) and overall survival (OS). Cox proportional hazards regressions and Kaplan-Meier survival analysis were performed.

RESULTS

For 122 patients, the mean age was 60.5 years and 49.2% were female. Median time to detection of the metastasis was 11 months, and 41.8% were ipsilateral to the primary lung cancer. Median DFS was 40 months (1 year: 64.8%; 5 year: 42.9%). Factors associated with longer DFS included primary tumor resection [hazard ratio (HR): 0.001; p = 0.005], longer time to adrenal metastasis (HR: 0.94; p = 0.005), and ipsilateral metastases (HR: 0.13; p = 0.004). Shorter DFS corresponded with older age (HR: 1.11; p = 0.01), R1 resection (HR: 8.94; p = 0.01), adjuvant radiation (HR: 9.45; p = 0.02), and open adrenal metastasectomy (HR: 10.0; p = 0.03). Median OS was 47 months (1 year: 80.2%; 5 year: 35.2%). Longer OS was associated with ipsilateral metastasis (HR: 0.55; p = 0.02) and adjuvant chemotherapy (HR: 0.35; p = 0.02). Shorter OS was associated with extra-adrenal metastases at adrenalectomy (HR: 3.52; p = 0.007), small cell histology (HR: 15.0; p = 0.04), and lung radiation (HR: 3.37; p = 0.002).

DISCUSSION

Durable survival was observed in patients undergoing adrenal metastasectomy and should be considered for isolated adrenal metastases of NSCLC. Small cell histology and extra-adrenal metastases are relative contraindications to adrenal metastasectomy.