Outcomes of adrenalectomy for isolated synchronous versus metachronous adrenal metastases in non-small-cell lung cancer: A systematic review and pooled analysis

Purpose Several small studies have reported that an adrenalectomy for isolated adrenal metastasis in non-small-cell lung cancer (NSCLC), along with a surgical resection for the primary lung cancer, can be curative. However, some suggest that the survival outcome among patients with a synchronous metastasis is poor. It remains unclear whether this treatment approach is warranted among those with synchronous metastasis. Methods A search for publications on adrenalectomy for NSCLC was performed via the MEDLINE database. Studies reporting on survival outcomes and containing at least four analyzable patients who had surgery for primary lung cancer were included. Those not allowing separation of outcomes between synchronous and metachronous metastases were excluded. Synchronous metastasis was defined as a disease-free interval (DFI) of 6 months or less. Results There were 10 publications contributing 114 patients; 42% of patients had synchronous metastases and 58% had metachronous metastases. The median DFIs were 0 and 12 months, respectively. Patients in the synchronous group were younger than those in the metachronous group (median age 54 v 68 years). Complications from adrenalectomy were infrequent. Median overall survival was shorter for patients with synchronous metastasis than those with metachronous metastasis (12 months v 31 months, generalized Wilcoxon P value = .02). However, the 5-year survival estimates were equivalent at 26% and 25%, respectively. Conclusion For an isolated adrenal metastasis from NSCLC, patients with a synchronous metastasis who underwent adrenalectomy had a shorter median overall survival than those with a metachronous metastasis. However, a durable long-term survival is achieved in approximately 25% in both groups.