PANOMEN-3 grading score is reliable in predicting pituitary adenoma behavior and prognosis: a single center cohort study

Background: Pituitary adenomas (PAs) comprise a heterogeneous group of diseases: a scoring system to guide prognosis and therapy is still missing. Methods: We assessed a retrospective single-center cohort of 401 patients with PAs followed over the last two decades using a newly developed Pituitary Society grading system, PANOMEN-3. Results: A high initial grade of the adenoma predicted a worse long-term outcome despite multimodal treatments (grade 3, disease remission OR 0.49, 95%CI [0.27; 0.84], p = 0.01). The grade could predict tumor behavior following surgery: a higher grade at baseline predicted relapses after disease remission (grade 3 vs grade 1/2, p = 0.01) and a higher postoperative grade predicted the need for additional treatments in case of persisting disease (grade 2/3 vs grade 1, p = 0.02). A score downgrade obtained with primary medical predicted the reduction of additional interventions and long-term biochemical control. When considering CD patients, both a lower initial grade (grade 2 vs grade 3, p < 0.01) and preoperative eucortisolism (p = 0.04) reduced recurrence risk. Contrarily to the whole-cohort analysis, grade predicted the surgical outcome in non-functioning pituitary adenomas and in acromegaly. Conclusion: Our data suggest for the first time that PANOMEN-3 grade system could be useful in everyday clinical practice, aiding physicians in both improving follow-up strategies for patients in remission and in the management of persisting disease for all pituitary adenomas. Especially for CD, a high initial grade could encourage clinicians to institute preoperative medical treatment and to adopt a closer follow-up schedule in cured cases.