2012 Comparison of Outcomes Following Surgical Intervention for MRI-Positive Versus MRI-Negative Cushing’s Disease: A Multi-Center Study

INTRODUCTION: Successful surgical treatment of biochemically confirmed Cushing’s Disease (CD) is challenging in patients who have no adenoma visible on preoperative magnetic resonance imaging (MRI). It is unclear whether MRI status affects patient outcomes in CD. METHODS: In this retrospective study analyzing data from the Registry of Adenomas of the Pituitary and Related Disorders (RAPID), adult patients with CD were stratified into two groups based on the presence or absence of a visible adenoma on preoperative imaging. Patients were excluded from the study if they had prior surgery or radiation therapy for CD. Rates of short-term remission, reoperation, and postoperative histopathology were compared. Remission was determined at individual centers using current guidelines set forth by the Endocrine Society. RESULTS: Of 648 patients, 587 (90.6%) had MRI-positive CD, and 61 (9.4%) had MRI-negative CD. There was no significant difference in remission rates between MRI-positive and MRI-negative CD (82.4% vs. 74.1%, p=0.13). When accounting for microadenomas alone (n=391, 66.6%), rate of remission remained similar between groups (82.6% vs. 74.1%, p=0.12). Adjuvant radiation and pharmacotherapy were used in 117 (22.1%) MRI-positive patients and 8 (13.3%) MRI-negative patients to achieve remission (p=0.12). The unadjusted odds of remission following surgery were 0.61 (0.33, 1.15 95% CI) times lower for MRI-negative patients (p=0.13). ACTH-staining adenomas were confirmed in 487 (88.7%) MRI-positive patients compared to 25 (47.1%) MRI-negative patients (p<0.0001). There was no significant difference in complication rates (26.4% vs. 36.1%, p=0.11) or rates of reoperation (8.2% vs. 11.9%, p=0.34). CONCLUSIONS: Surgical intervention leads to similar rates of remission for MRI-positive and MRI-negative CD, although multimodal treatment with radiation and pharmacotherapy is common. Future collaborative efforts via the RAPID Consortium are critical to understanding long-term hormonal control in MRI-negative CD patients.