Endocrine Abstracts

Background: Non-functioning pituitary adenomas (NFAs) are slow growing tumours with reported 5-year recurrence rates following resection up to 51%. The time point that it is safe to stop surveillance imaging is not clearly defined.

Aim: To clarify the time spectrum of recurrence in patients with NFAs offered solely surgery as primary treatment and to estimate the safe time to stop surveillance pituitary imaging.

Methods: Case-note analysis of all patients who underwent surgery for NFA between 01/1984 and 2/2007 was undertaken. Patients treated only by surgery and not adjuvant radiotherapy with a minimum follow-up of 1 year were included. Surveillance imaging was performed by scans every 1–2 years for the first 10 years and every 2–3 years thereafter. Recurrence was diagnosed on the basis of radiological appearances (tumour detection after total removal or tumour growth after partial resection) with or without associated manifestations.

Results: One hundred and fifty-two patients (95 males, median age at diagnosis 59.5 years (range 18–88)) met the inclusion criteria. Mean observation period following surgery was 6 years (median 4.3 (range 1–25.8)). Recurrence was documented in 57 cases (37.5%). Kaplan–Meier analysis showed relapse rates of 25.4, 45.5, and 62.1% at 5-, 10- and 15-years, respectively. 50% of the recurrences were detected by 4.8 years, 75% by 8.8 years and 95% by 17.2 years (range 1–25.8). 22.7% of the patients had recurrence 10 years after the surgery.

Conclusion: In this large series of subjects with NFA (treated solely by surgery) and followed-up for an extensive period, we have shown that significant number (22.7%) of patients develop recurrence 10 years after the surgery. These results importantly suggest that these subjects need to be closely monitored following surgery with yearly imaging for the first 5 years and 2 yearly thereafter, to pick up recurrences early. Exact frequency of imaging is yet to be determined.