Short-Term Risk of Recurrence of Surgically Treated, Radiotherapy-Naive Pituitary Adenomas

Introduction: Risk of recurrent pituitary adenoma (PA) seems highest within 5 years following surgery; however, despite comparable studies, the absolute risk is unknown. We aimed to define the natural history of a large cohort with surgically treated, radiation-naive PAs.

Methods: A retrospective audit of 812 patients with pituitary tumors treated at our institution between 2001 and 2011 was performed, assessing pituitary function, tumor characteristics, incidence and timing of recurrence, and need for additional surgery. Median follow-up was 88 months (range, 11–494 months). Cushing's and nonadenomatous pathology cases were excluded.

Results: Mean time to initial recurrence was 33.2 months (STD, 46.3), documented in 57 patients (7.0%), with 34 males and 23 females and median age 50 years, who underwent 84 transsphenoidal operations and 14 craniotomies. Presenting median tumor volume was 14.1 cm³ (range, 0.2–175 cm³). Extension into the cavernous sinus and/or suprasellar region was noted in 39 patients. There were 33 non-secreting tumors (60%), 8 growth hormone (15%), 7 silent-ACTH (13%), 5 prolactin (9%), and 1 mixed type (2%). Early (≤4 years) and late recurrence were noted in 45 (79%) and 12 (21%) patients, respectively. All patients had partial or panhypopituitarism and nine underwent three or more operations.

Conclusion: The recurrence rate of PA was low, but not insignificant. Patients with cavernous sinus and suprasellar extension had a disproportionately higher risk of recurrence. We conclude that a conservative “wait and see” policy aimed at sparing patients of the side effects of radiation should be adopted for most PA.