Conservatively managed non-functioning pituitary macroadenomas-cohort study from the UK Non-functioning Pituitary...

Area of Science:

• Endocrinology
• Neurosurgery
• Oncology

Background:

• Asymptomatic non-functioning pituitary macroadenomas (macroNFPAs) are often monitored, but evidence for optimal surveillance frequency and surgical indications is limited.
• Uncertainty exists regarding the best approach for managing macroNFPAs, impacting patient care and resource allocation.

Purpose of the Study:

• To assess the natural history and outcomes of patients with macroNFPAs managed initially with monitoring.
• To provide evidence-based recommendations for surveillance protocols and surgical indications in macroNFPAs.

Main Methods:

• A multicentre, retrospective cohort study analyzed data from 949 patients across 21 UK endocrine departments between 2005 and 2022.
• Clinical, imaging, and hormonal data were collected and analyzed to evaluate tumor behavior and patient outcomes.

Main Results:

• Tumor enlargement occurred at a rate of 9.8 per 100 patient-years, with higher incidence in tumors near the optic chiasm.
• For macroNFPAs not in contact with the optic chiasm, initial enlargement did not impact visual fields; 60.5% of enlarged tumors continued to grow during monitoring.
• New pituitary hormone deficits occurred in 4.0%-4.9% of patients, primarily due to tumor enlargement, while surgical intervention showed limited rates of hypopituitarism reversal.

Conclusions:

• Less frequent imaging is recommended for macroNFPAs not in contact with the optic chiasm, with the first follow-up scan potentially delayed to one year.
• Tumor behavior after initial enlargement is variable, and new hypopituitarism in stable tumors is rare, suggesting a re-evaluation of regular pituitary function assessments.
• The findings support refined monitoring protocols for macroNFPAs, optimizing surveillance strategies and potentially reducing unnecessary interventions.