Adrenal insufficiency in immunochemotherapy for small-cell lung cancer with ectopic ACTH syndrome.

The immune checkpoint inhibitor atezolizumab has recently been approved for the treatment of small-cell lung cancer (SCLC). Approximately 1-6% of tumour ectopically produce ACTH and cause ectopic ACTH syndrome (EAS) as an endocrine paraneoplastic syndrome. The use of combined chemotherapy and atezolizumab in the ectopic ACTH syndrome secondary to small-cell lung cancer may cause a precipitous fall in circulating ACTH/cortisol, resulting in symptomatic adrenal insufficiency The advances in cancer therapy and treatment for endocrine paraneoplastic syndrome need to be adapted.