Outcomes of surgical treatment for isolated adrenal metastasis from non-small cell lung cancer

Objective: Long-term survival of patients who undergo surgical resection of isolated adrenal metastasis instead of nonsurgical treatment has shown higher values than those described for stage IVA. The primary endpoint was to evaluate overall survival (OS) of patients with single adrenal metastasis from non-small cell lung cancer (NSCLC), who underwent surgical treatment. The secondary endpoint was to evaluate and compare the OS and disease-free survival (DFS) according to: pathological lung tumour size, histology, lymph node involvement, type of metastasis at the time of diagnosis and laterality of the metastasis according to the primary lung tumour.

Methods: From August 2007 to March 2020, 13 patients with isolated adrenal gland metastasis were identified. We performed a descriptive observational study including patients with diagnosed single adrenal gland metastasis of resectable primary lung cancer and no history of other malignant disease. Clinical data obtained included patient demographics, metastases characteristics, laterality of the metastasis, time between surgeries, length of follow-up, survival status, pathological lung tumour size, histology and lymph node involvement. The variables analysed were OS and DFS.

Results: Median global OS was 31.9 months (interquartile range (IQR), 19.1-51.4). The 2- and 5-year OS estimated was 54% (95% CI: 29.5%-77.4%) and 36% (95% CI: 13.4%-68.1%), respectively. In patients with NSCLC without mediastinal lymph node involvement, we obtain a median OS of 40 months (IQR, 27.4-51.4) and a 2- and 5-year OS estimated of 75% (95% CI: 43.2%-92.2%) and 50% (95% CI: 18.7%-81.2%), respectively. Recurrence was detected in five patients with a median DFS of 11.9 months (IQR, 6-34.2).

Conclusion: The resection of the adrenal metastasis should be considered if the primary lung cancer is resectable. Presence of mediastinal lymph node involvement should be ruled out through invasive staging of the mediastinum before performing adrenal and lung surgery. Proper selection of patients who would benefit from surgery is essential to obtain better survival results.