Factors Associated with the Use of Radiation Therapy for the Treatment of Pituitary Adenoma in the National Cancer Database

Purpose: Radiation therapy is rarely used as primary treatment for pituitary adenoma; however, it can be an important option in the face of certain patient and tumor characteristics. There are few large studies evaluating how radiation therapy is used for the treatment of these benign tumors. Investigating these trends and identifying factors that predict the incorporation of radiation therapy into pituitary adenoma treatment would help to better inform treatment decisions and improve patient outcomes.

Design: Retrospective analysis of cases using the National Cancer Database.

Setting: Tertiary academic medical center.

Participants: Patients diagnosed with pituitary adenoma between 2004 and 2014 within the NCDB.

Main Outcome Measures: Incorporation of radiation therapy into treatment for pituitary adenoma.

Methods: Our sample consisted of all patients diagnosed with pituitary adenomas between 2004 and 2014. Univariate and multivariate analyses were performed to examine the relationship between patient, tumor, and treatment factors and use of radiation therapy in the treatment of pituitary adenomas. Multivariable analysis included age, sex, race, comorbidity score, facility type, and year of diagnosis.

Results: A total of 76,336 patients met inclusion criteria. Inclusion of radiation therapy in pituitary adenoma treatment was 8.0% in 2004 and steadily declined to a low of 3.1% in 2014. After adjustment, patients who were female, black, or treated at either a Comprehensive Community Cancer Program or an Integrated Network Cancer Program were more likely to receive radiation as part of their pituitary adenoma treatment (p < 0.001). Overall, patients were less likely to receive radiation for their pituitary adenoma over time. The proportion of patients with positive margins who received radiation declined over time, from 31.0% in 2004 to 16.1% in 2014, constituting a driving factor for the decline in the use of radiation therapy in treating pituitary adenomas in this time period (p < 0.05).

Conclusion: In this sample of pituitary adenoma patients treated at National Cancer Database institutions between 2004 and 2014, we found a steady decline in the use of radiation therapy for treatment of pituitary adenomas. This decline was partially accounted for by the decline in the proportion of patients with a positive margin status receiving radiation therapy.