The natural history of surgically treated but radiotherapy-naïve nonfunctioning pituitary adenomas

Abstract

Background and objectives: Transsphenoidal surgery is indicated for patients with nonfunctioning pituitary adenomas (NFPAs) causing compressive symptoms. Previous studies attempting to define the rate of recurrence/regrowth of surgically treated but radiation-naïve NFPAs were somewhat limited by selection bias and/or small numbers and/or lack of consistency of findings between studies. A better understanding of the natural history of this condition could allow stratification of recurrence risk and inform future management. We aimed to define the natural history of a large, mainly unselected cohort with surgically treated, radiotherapy (RT)-naïve NFPAs and to try to identify predictors of recurrence/regrowth.

Design: Case-note analysis of all patients who underwent surgery for NFPA in our hospital between 1980 and 2006 was undertaken. Median follow-up was 5.7 (range 1-25) years.

Patients: A total of 212 patients were identified of which 159 were suitable for analysis. 93% did not receive post-operative RT.

Measurement: Post-operative recurrent/regrowth was defined by any increase in tumour remnant size on serial post-operative pituitary imaging.

Results: Recurrence/regrowth was documented in 53 patients (33.5%). Multivariate analysis revealed size of the post-operative tumour remnant and length of follow-up to be the two major determinants of recurrence/regrowth. The presence of a tumour with an extrasellar remnant was associated with the highest risk of recurrence (odds ratio 3.73 [CI: 1.97-7.09]), while no recurrence was seen in those with no residual tumour post-operatively and regrowth risk was intermediate for those with remaining intrasellar remnant.

Conclusion: These results indicate that patients with post-operative tumour with an extrasellar remnant should be considered routinely for adjuvant RT to reduce the risk of tumour regrowth while those with no residual tumour can be safely observed. Individualized decisions should be made for patients with an intrasellar remnant.