Oral Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

Use of temozolomide in a large cohort of patients with aggressive pituitary tumours (#47)

Ann McCormack 1 2 , Olaf Dekkers 3 , Stephan Petersenn 4 , Vera Popovic 5 , Jacqueline Trouillas 6 7 , Gerald Raverot 6 8 9 , Pia Burman 10
  1. Hormones and Cancer Group, Garvan Institute of Medical Research, Sydney, Australia
  2. St Vincent's Hospital, Darlinghurst, NSW, Australia
  3. Clinical Epidemiology and Endocrinology, Leidin University Medical Centre, Leidin, Netherlands
  4. ENDOC Center for Endocrine Tumors, Hamburg, Germany
  5. Medical Faculty, University Belgrade, Belgrade, Serbia
  6. Faculty of Medicine Lyon-Est, University of Lyon, Lyon, France
  7. Centre de Pathologie et de Biologie Est, Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, Bron, France
  8. Fédération d'EndocrinologieGroupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France
  9. INSERM U1052, CNRS UMR5286, Cancer Research Centre of Lyon, Lyon, France
  10. Department of Endocrinology, Skane University Hospital, University of Lund, Malmo, Sweden

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.