Performance of EUS-FNA and EUS-B-FNA for the diagnosis of left adrenal glands metastases in patients with lung cancer: A systematic review and meta-analysis

Objectives: For diagnosing left adrenal gland metastasis in lung cancer, clinical guidelines recommend to perform EUS, but EUS-B (EUS using an EBUS-scope) is increasingly being used. We evaluated the diagnostic performance of both procedures. Materials and Methods: We did a systematic review (PROSPERO, CRD42023416205) and searched MEDLINE and EMBASE on 04-July-2023 for studies evaluating EUS and/or EUS-B in diagnosing left adrenal gland metastases in adults with (suspected) lung cancer. Outcomes were: (1) ability to visualize the left adrenal gland, (2) ability to sample (in those with successful visualization and in whom sampling was attempted), (3) ability to obtain adequate material (in those with successful sampling), (4) malignancy detection rate (in those with successful sampling), and (5) remaining risk of malignancy (in those with a negative EUS(-B)-FNA and undergoing a reference standard). We performed random-effects meta-analyses. Results: We included 19 studies (EUS: n = 11, EUS-B: n = 6, both: n = 2), covering 1712 patients. All studies had high (n = 18) or unclear (n = 1) risk of bias (QUADAS-2). Average ability to visualize the left adrenal gland was 0.94 (95 %CI 0.82–0.98; n = 7 studies). Average ability to sample was 1.00 (95 %CI 0.99–1.00; n = 9). Average ability to obtain adequate material was 0.96 (95 %CI 0.93–0.98; n = 18). Average malignancy detection rate was 0.42 (95 %CI 0.34–0.49; n = 18). Remaining risk of malignancy was 0.07 (95 %CI 0.04–0.12; n = 8). Ability to visualize was slightly higher for EUS (0.99; 95 %CI 0.90–1.00) than EUS-B (0.84; 95 %CI 0.70–0.92; p = 0.025), but the other performance characteristics were similar. No major complications were reported. Conclusion: Both EUS and EUS-B have good performance and are safe for left adrenal gland analysis in patients with lung cancer, but the number of high-quality studies is limited and further well-constructed prospective studies are needed.