Subgroup analysis after pathological re-evaluation: NET G3 and NEC
NEC, tumour, NEC-like
TUMOUR, MINEN
All 37 patients were re-evaluated according to the 2019 WHO classification, identifying 26 NET G3, nine NEC, one mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) and one case with ambiguous morphology. Pathological re-evaluation confirmed a Ki-67 ≤ 55% in 30 patients, while seven patients had Ki-67 > 55%, among them 4 NEC, 2 NET G3 and one case of MiNEN. Somatostatin receptor imaging (SRI) was positive in 17/20 NET G3 (85%) and 3/7 NEC patients (43%). Three NET G3 patients had a history of previous low/intermediate NET. Two patients experienced a transformation from NET to a tumour with NEC-like features, one before and one after study inclusion.DCR at 6 months was 77% for NET G3 and 22% for NEC (Univariate analysis for the NET G3 subgroup identified Ki-67 > 55% and CRP > 10 mg/L as predictors for shorter PFS, but not for OS. For the seven patients with Ki-67 > 55%, three patients had CRP ≤ 10, and four patients had CRP > 10.