Contemporary conditional cancer-specific survival rates in surgically treated adrenocortical carcinoma patients: A stage-specific analysis

Background and objectives: We examined the effect of disease-free interval (DFI) duration on cancer-specific mortality (CSM)-free survival, otherwise known as the effect of conditional survival, in surgically treated adrenocortical carcinoma (ACC) patients. Methods: Within the Surveillance, Epidemiology, and End Results database (2004-2018), 867 ACC patients treated with adrenalectomy were identified. Conditional survival estimates at 5-years were assessed based on DFI duration and according to stage at presentation. Separate Cox regression models were fitted at baseline and according to DFI. Results: Overall, 406 (47%), 285 (33%), and 176 (20%) patients were stage I-II, III and IV, respectively. In conditional survival analysis, providing a DFI of 24 months, 5-year CSM-free survival at initial diagnosis increased from 66% to 80% in stage I-II, from 35% to 66% in stage III, and from 14% to 36% in stage IV. In multivariable Cox regression models, stage III (hazard ratio [HR]: 2.38; p < 0.001) and IV (HR: 4.67; p < 0.001) independently predicted higher CSM, relative to stage I-II. The magnitude of this effect decreased over time, providing increasing DFI duration. Conclusions: In surgically treated ACC, survival probabilities increase with longer DFI duration. This improvement is more pronounced in stage III, followed by stages IV and I-II patients, in that order. Survival estimates accounting for DFI may prove valuable in patients counseling.