Predictors of disease recurrence after curative surgery for nonfunctioning pancreatic neuroendocrine neoplasms (NF-PanNENs): a systematic review and meta-analysis.

PURPOSE: Patients submitted to curative surgery for non-functioning pancreatic neuroendocrine neoplasms (NF-PanNENs) exhibit a variable risk of disease relapse. Aims of this meta-analysis were to estimate the rate of disease recurrence and to investigate the risk factors for disease relapse in patients submitted to curative surgery for NF-PanNENs. METHODS: Medline/Pubmed and Web of Science databases were searched for relevant studies. A meta-regression analysis was performed to investigate the source of recurrence rate heterogeneity. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CI) were used to assess the effect of each possible prognostic factor on disease-free survival. RESULTS: Fifteen studies, involving 2754 patients submitted to curative surgery for NF-PanNENs, were included. The pooled rate of disease recurrence was 21% (95% CI 15-26%). Study quality (Odds ratio, OR 0.94, P = 0.016) and G3-PanNENs rate (OR 2.18, P = 0.040) independently predicted the recurrence rate variability. Nodal metastases (HR 1.63, P < 0.001), tumor grade G2-G3 (G1 versus G2: HR 1.72, P < 0.001, G1 versus G3 HR 2.57, P < 0.001), microvascular (HR 1.25, P = 0.046) and perineural (HR 1.29, P = 0.019) invasion were identified as significant prognostic factors. T stage (T1-T2 versus T3-T4, P = 0.253) and status of resection margins (R0 versus R1, P = 0.173) did not show any significant relationship with NF-PanNENs recurrence. CONCLUSION: Disease relapse occurs in approximately one out of five patients submitted to curative surgery for NF-PanNENs. Nodal involvement, tumor grade, microvascular and perineural invasion are relevant prognostic factors, that should be taken into account for follow-up and for possible trials investigating adjuvant or neoadjuvant treatments.

Sporadic non-functioning pancreatic neuroendocrine tumours: multicentre analysis.

BACKGROUND: Outcomes after surgery for sporadic pancreatic neuroendocrine neoplasms (Pan-NENs) were evaluated. METHODS: This multicentre study included patients who underwent radical pancreatic resection for sporadic non-functioning Pan-NENs. In survival analysis, the risk of mortality in this cohort was analysed in relation to that of the matched healthy Italian population. Relative survival (RS) was calculated as the rate between observed and expected survival. Factors related to RS were investigated using multivariable modelling. RESULTS: Among 964 patients who had pancreatic resection for sporadic non-functioning Pan-NENs, the overall RS rate was 91.8 (95 per cent c.i. 81.5 to 96.5) per cent. 2019 WHO grade (hazard ratio (HR) 5.75 (s.e. 4.63); P = 0.030) and European Neuroendocrine Tumour Society (ENETS) TNM stage (6.73 (3.61); P < 0.001) were independent predictors of RS. The probability of a normal lifespan for patients with G1, G2, G3 Pan-NENS, and pancreatic neuroendocrine carcinomas (Pan-NECs) was 96.7, 54.8, 0, and 0 per cent respectively. The probability of a normal lifespan was 99.8, 99.3, 79.8, and 46.8 per cent for those with stage I, II, III, and IV disease respectively. The overall disease-free RS rate was 73.6 (65.2 to 79.5) per cent. 2019 WHO grade (HR 2.10 (0.19); P < 0.001) and ENETS TNM stage (HR 2.50 (0.24); P < 0.001) significantly influenced disease-free RS. The probability of disease-free survival was 93.2, 84.9, 45.2, and 6.8 per cent for patients with stage I, II, III, and IV disease, and 91.9, 45.2, 9.4, and 0.7 per cent for those with G1, G2, G3 Pan-NENS, and Pan-NECs, respectively. CONCLUSION: A surgical approach seems without benefit for Pan-NECs, and unnecessary for small G1 sporadic Pan-NENs. Surgery alone may be insufficient for stage III-IV and G3 Pan-NENs.