A Prospective Multicenter Study Evaluating Secondary Adrenal Suppression After Antiemetic Dexamethasone Therapy in Cancer Patients Receiving Chemotherapy: A Korean SouthWest Oncology Group Study

Background. In a previous pilot study, adrenal suppression was found to be common after antiemetic dexamethasone therapy in cancerpatients.Theobjectiveofthis largeprospectivemulticenter study was to confirm the incidence and factors associated with secondary adrenal suppression related to antiemetic dexamethasone therapy in cancer patients receiving chemotherapy. Methods. Chemotherapy-näıvepatientswhowere scheduled to receive at least three cycles of highly or moderately emetogenic chemotherapy with dexamethasone as an antiemetic were enrolled. Patients with a suppressed adrenal response before chemotherapy or those administered corticosteroids within 6 months of enrollment in the study were excluded. Results. Between October 2010 and August 2014, 481 patients receiving chemotherapy underwent the rapid adrenocorticotropic hormone (ACTH) stimulation test to assess eligibility; 350 of these patients were included in the final analysis. Fifty-six patients (16.0%) showed a suppressed adrenal response in the rapid ACTH stimulation test at 3 or 6 months after the start of the first chemotherapy. The incidence of adrenal suppression was affected by age, performance status, stage, and use of megestrol acetate in univariate analysis. Multivariate analysis revealed that secondary adrenal suppression associated with antiemetic dexamethasone therapy was significantly associated with megestrol acetate treatment (odds ratio: 3.06; 95% confidence interval: 1.60 to 5.86; p, .001). Conclusion.This large prospective study indicates that approximately 15% of cancer patients receiving chemotherapy with a normal adrenal response show suppressed adrenal responses after antiemetic dexamethasone therapy. This result was particularly significant for patients cotreated with megestrol acetate. The Oncologist 2015;20:1432–1439 Implications for Practice: This large prospective multicenter study indicates that approximately 15% of cancer patients receiving chemotherapy with a normal adrenal response show secondary adrenal suppression after antiemetic dexamethasone therapy. Adrenal suppression was particularly significant for patients cotreated with megestrol acetate. Clinicians need increased awareness of the potential for adrenal insufficiency secondary to antiemetic dexamethasone therapy in cancer patients receiving chemotherapy. These findings should help encourage prospective studies designed to determine the adequate doses and durations of antiemetic dexamethasone therapy required to reduce dexamethasone-related adverse effects while controlling chemotherapy-induced nausea and vomiting. Correspondence: Ki Hyeong Lee, M.D., Ph.D, Department of Internal Medicine, College of Medicine, Chungbuk National University, 52, Naesudong-ro, Seowon-gu, Cheongju 361-763, Republic of Korea. Telephone: 82-43-269-6015; E-Mail: kihyeonglee7030@hanmail. net Received May 24, 2015; accepted for publication August 24, 2015; published Online First on October 13, 2015. ©AlphaMed Press 1083-7159/2015/$20.00/0 http://dx.doi.org/10.1634/theoncologist.2015-0211 TheOncologist 2015;20:1432–1439 www.TheOncologist.com ©AlphaMed Press 2015 CM E