Background and objectives: Despite growing interest in how patient frailty affects outcomes (eg, in neuro-oncology), its role after transsphenoidal surgery for Cushing disease (CD) remains unclear. We evaluated the effect of frailty on CD outcomes using the Registry of Adenomas of the Pituitary and Related Disorders (RAPID) data set from a collaboration of US academic pituitary centers.

Methods: Data on consecutive surgically treated patients with CD (2011-2023) were compiled using the 11-factor modified frailty index. Patients were classified as fit (score, 0-1), managing well (score, 2-3), and mildly frail (score, 4-5). Univariable and multivariable analyses were conducted to examine outcomes.

Results: Data were analyzed for 318 patients (193 fit, 113 managing well, 12 mildly frail). Compared with fit and managing well patients, mildly frail patients were older (mean ± SD 39.7 ± 14.2 and 48.9 ± 12.2 vs 49.4 ± 8.9 years, P < .001) but did not different by sex, race, and other factors. They had significantly longer hospitalizations (3.7 ± 2.0 and 4.5 ± 3.5 vs 5.3 ± 3.5 days, P = .02), even after multivariable analysis (β = 1.01, P = .007) adjusted for known predictors of prolonged hospitalization (age, Knosp grade, surgeon experience, American Society of Anesthesiologists grade, complications, frailty). Patients with mild frailty were more commonly discharged to skilled nursing facilities (0.5% [1/192] and 4.5% [5/112] vs 25% [3/12], P < .001). Most patients underwent gross total resection (84.4% [163/193] and 79.6% [90/113] vs 83% [10/12]). No difference in overall complications was observed; however, venous thromboembolism was more common in mildly frail (8%, 1/12) than in fit (0.5%, 1/193) and managing well (2.7%, 3/113) patients ( P = .04). No difference was found in 90-day readmission rates.

Conclusion: These results demonstrate that mild frailty predicts CD surgical outcomes and may inform preoperative risk stratification. Frailty-influenced outcomes other than age and tumor characteristics may be useful for prognostication. Future studies can help identify strategies to reduce disease burden for frail patients with hypercortisolemia.