Objective: To collect clinical and treatment outcome data in a large patient cohort, and specifically to report experience with temozolomide (TMZ).
Design: Cohort study based on an electronic survey distributed to European Society of Endocrinology (ESE) members Dec 2015-Nov 2016.
Results: Reports on 166 patients including 40 pituitary carcinomas (PC) and 125 aggressive pituitary tumours (APT). Median age at diagnosis was 43 (range 4 to 79) years. 59% of tumours were clinically functioning at presentation. The majority of the cohort (69%) comprised ACTH and PRL tumours pathologically. There was no significant difference in the mean Ki67 between PC (11%) and APT (12%). TMZ was the first line chemotherapy in 156 patients. At the end of TMZ treatment (mean 10 cycles) radiological evaluation showed complete response in 6%, partial response in 31%, stable disease in 33% and progressive disease in 30 %. Clinically silent tumours showed less regression compared with secreting tumours, 17 % vs 45 % (p=0.01). Complete response was only seen in patients with low MGMT expression. Concomitant radiotherapy and TMZ was associated with an increased response rate, 71% vs 37% (p=0.05). Median follow-up after cessation of TMZ treatment was 21 months. Of patients with complete response, partial response and stable disease 25%, 40% and 48% respectively showed progression during further follow-up. The mean time to progression was 18.4 months after TMZ cessation. 25 patients received a second course of TMZ, 2 had a partial response. Overall mortality was 34%, and highest in patients demonstrating progression on or following TMZ treatment (50%).
Conclusion: TMZ was accompanied by tumour regression in 37% of patients overall, documenting its value in the management of these aggressive tumours. The high recurrence rate following TMZ cessation highlights the need to identify additional effective therapies.