A practical algorithm to predict postsurgical recurrence and progression of pituitary neuroendocrine tumours (PitNET)s

Objective Pituitary neuroendocrine tumours (PitNET)s can be aggressive, thus presenting local invasion, postsurgical recurrence and/or resistance to treatment, responsible for significant morbidity. The study aimed at identifying prognostic factors of postsurgical outcome using data‐driven classification of patients. Design Retrospective observational study. Methods Clinicopathological and radiological data of patients with PitNET treated via endoscopic endonasal surgery were collected. Tumour recurrence/progression and progression‐free survival were assessed by classification tree analysis (CTA) and Kaplan‐Meier curves, respectively. Histological subtype, cavernous/sphenoid sinus invasion, mitosis, Ki‐67, p53, Trouillas’ grading, degree of tumour exeresis and postsurgery disease activity were also evaluated. Results A total of 1066 (466 gonadotroph, 287 somatotroph, 148 lactotroph, 157 corticotroph and 8 thyrotroph) tumours were included; 21.7% invaded the cavernous/sphenoid sinus. Based on Trouillas’ classification, 64.3% were grade 1a, 14.2% 1b, 16.1% 2a, and 5.4% 2b; 18.3% had >2/10 HPF mitoses, 24.9% had Ki‐67 ≥3%; 15.8% were positive for p53. Exeresis was radical in 81.2% of the cases. Median follow‐up was 59.2 months. At last evaluation, 79.4% of the patients were cured; 20.6% had disease persistence, controlled by medical treatment in 18.3% of them. Disease recurrence/progression was recorded in 10.9% of the cases. CTA identified 5 distinct patient subgroups with different risk of disease recurrence/progression. Grade 2 of the Trouillas’ grading, >2/10 HPF mitoses, Ki‐67 ≥3%, p53 protein expression (P