68Ga-DOTATOC PET/MR imaging and radiomic parameters in predicting histopathological prognostic factors in patients with pancreatic neuroendocrine well-differentiated tumours.

PURPOSE: To explore the role of fully hybrid 68Ga-DOTATOC PET/MR imaging and radiomic parameters in predicting histopathological prognostic factors in patients with pancreatic neuroendocrine tumours (PanNETs) undergoing surgery. METHODS: One hundred eighty-seven consecutive 68Ga-DOTATOC PET/MRI scans (March 2018-June 2020) performed for gastroenteropancreatic neuroendocrine tumour were retrospectively evaluated; 16/187 patients met the eligibility criteria (68Ga-DOTATOC PET/MRI for preoperative staging of PanNET and availability of histological data). PET/MR scans were qualitatively and quantitatively interpreted, and the following imaging parameters were derived: PET-derived SUVmax, SUVmean, somatostatin receptor density (SRD), total lesion somatostatin receptor density (TLSRD), and MRI-derived apparent diffusion coefficient (ADC), arterial and late enhancement, necrosis, cystic degeneration, and maximum diameter. Additionally, first-, second-, and higher-order radiomic parameters were extracted from both PET and MRI scans. Correlations with several PanNETs' histopathological prognostic factors were evaluated using Spearman's coefficient, while the area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to evaluate parameters' predictive performance. RESULTS: Primary tumour was detected in all 16 patients (15/16 by 68Ga-DOTATOC PET and 16/16 by MRI). SUVmax and SUVmean resulted good predictors of lymphnodal (LN) involvement (AUC of 0.850 and 0.783, respectively). Second-order radiomic parameters GrayLevelVariance and HighGrayLevelZoneEmphasis extracted from T2 MRI demonstrated significant correlations with LN involvement (adjusted p = 0.009), also showing good predictive performance (AUC = 0.992). CONCLUSION: This study demonstrates the role of the fully hybrid PET/MRI tool for the synergic function of imaging parameters extracted by the two modalities and highlights the potentiality of imaging and radiomic parameters in assessing histopathological features of PanNET aggressiveness.

Role of chromogranin A-derived fragments after resection of nonfunctioning pancreatic neuroendocrine tumors.

PURPOSE: No single reliable biomarker is available for nonfunctioning pancreatic neuroendocrine tumors (NF-PanNETs). Vasostatin-1 (VS-1), the N-terminal fragment of chromogranin A (CgA), seems to be a more accurate biomarker compared to its precursor. Primary aim was to investigate the ability of VS-1, compared to total-CgA, to assess the effectiveness of surgical resection performed for NF-PanNETs. Secondary aim was to evaluate two additional CgA-derived fragments, pancreastatin (PST) and vasostatin-2 (VS-2), as possible biomarkers for NF-PanNETs. METHODS: Consecutive patients who underwent surgery for NF-PanNETs at San Raffaele Scientific Institute were included (n = 35). Plasma levels of CgA and CgA-derived fragments were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA), preoperatively and postoperatively. RESULTS: Preoperative VS-1 was significantly higher compared to VS-1 measured on postoperative day 5 (POD5) (pre: 0.338 nM versus POD5: 0.147 nM, P < 0.001), whereas total-CgA significantly increased after surgery (pre: 1.123 nM versus POD5: 1.949 nM, P = 0.006). Overall, 24 patients showed ≥ 1 feature of tumor aggressiveness (T3-T4, nodal/distant metastases, Ki67 > 5%, microvascular/perineural invasion, necrosis). The median percentage decrease in VS-1 plasma levels was 63% (IQR 28-88%) among patients with aggressive tumors, compared to 13% (IQR 0-57%) in the remaining population (P = 0.033). No significant differences in terms of PST (P = 0.870) and VS-2 (P = 0.909) were observed between preoperative and postoperative time. CONCLUSION: VS-1 provides an early assessment of surgical efficacy in patients who undergo resection for NF-PanNETs, especially in those with aggressive neoplasms. Total-CgA, PST and VS-2 have no clinical utility in this setting.

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.

Recurrence of Pancreatic Neuroendocrine Tumors and Survival Predicted by Ki67.

BACKGROUND: Despite evidence of different malignant potentials, postoperative follow-up assessment is similar for G1 and G2 pancreatic neuroendocrine tumors (panNETs) and adjuvant treatment currently is not indicated. This study investigated the role of Ki67 with regard to recurrence and survival after curative resection of panNET. METHODS: Patients with resected non-functioning panNET diagnosed between 1992 and 2016 from three institutions were retrospectively analyzed. Patients who had G1 or G2 tumor without distant metastases or hereditary syndromes were included in the study. The patients were re-categorized into Ki67 0-5 and Ki67 6-20%. Cox regression analysis with log-rank testing for recurrence and survival was performed. RESULTS: The study enrolled 241 patients (86%) with Ki67 0-5% and 39 patients (14%) with Ki67 6-20%. Recurrence was seen in 34 patients (14%) with Ki67 0-5% after a median period of 34 months and in 16 patients (41%) with Ki67 6-20% after a median period of 16 months (p < 0.001). The 5-year recurrence-free and 10-year disease-specific survival periods were respectively 90 and 91% for Ki67 0-5% and respectively 55 and 26% for Ki67 6-20% (p < 0.001). The overall survival period after recurrence was 44.9 months, which was comparable between the two groups (p = 0.283). In addition to a Ki67 rate higher than 5%, tumor larger than 4 cm and lymph node metastases were independently associated with recurrence. CONCLUSIONS: Patients at high risk for recurrence after curative resection of G1 or G2 panNET can be identified by a Ki67 rate higher than 5%. These patients should be more closely monitored postoperatively to detect recurrence early and might benefit from adjuvant treatment. A clear postoperative follow-up regimen is proposed.

Is there a role for surgical resection in patients with pancreatic cancer with liver metastases responding to chemotherapy?

BACKGROUND: New chemotherapeutic regimens have improved survival for stage IV pancreatic ductal adenocarcinoma and occasionally major response of liver metastases can be observed. Aim of this work is to analyze the outcomes of patients undergoing primary chemotherapy for liver metastases from pancreatic cancer and to evaluate the results of surgical resection. METHODS: Retrospective analysis. EXCLUSION CRITERIA: patients with extra-hepatic metastases, patients with Eastern Cooperative Oncology Group performance status ≥3, patients undergoing supportive care alone. RESULTS: 127 patients were identified. Liver metastases were unilobar in 28.5% of patients. Chemotherapy regimens included gemcitabine alone or in association with other agents (44%), oxaliplatin, irinotecan, fluorouracil and leucovorin (FOLFIRINOX 8%), and cisplatin, gemcitabine plus capecitabine and epirubicin (PEXG) or capecitabine and docetaxel (PDXG) or epirubicin and fluorouracil (PEFG) (48%). 56 patients (44%) had a complete (7%) or partial response (37%). surgical resection was carried out in 11 patients (8.5%). Median overall survival was 11 months for the entire cohort and 15 months for those with partial/complete response. In this sub-group median survival was significantly longer (46 versus 11 months) for patients undergoing resection (P < 0.0001). Independent predictors of overall survival were chemotherapy with multiple agents (HR: 0.512), surgical resection (HR: 0.360), >5 liver metastases at diagnosis (HR: 3.515), and CA 19.9 reduction < 50% of baseline value (HR: 2.708). CONCLUSIONS: Surgical resection of primary pancreatic tumor with or without residual liver disease can be considered in selected cases after primary chemotherapy and it is associated with improved survival.

Systematic review and meta-analysis of metal versus plastic stents for preoperative biliary drainage in resectable periampullary or pancreatic head tumors.

BACKGROUND: Preoperative biliary drainage (PBD) with stenting increases complications compared with surgery without PBD. Metallic stents are considered superior to plastic stents when considering stent-related complications. Aim of the present systematic review and meta-analysis is to compare the rate of endoscopic re-intervention before surgery and postoperative outcomes of metal versus plastic stents in patients with resectable periampullary or pancreatic head neoplasms. METHODS: We conducted a bibliographic research using the National Library of Medicine's PubMed database, including both randomized controlled trials (RCTs) and non-RCTs. Quantitative synthesis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Statistical heterogeneity was assessed using the I(2) tests. RESULTS: One RCT and four non-RCTs were selected, including 704 patients. Of these, 202 patients (29.5%) were treated with metal stents and 502 (70.5%) with plastic stents. The majority of patients (86.4%) had pancreatic cancer. The rate of endoscopic re-intervention after preoperative biliary drainage was significantly lower in the metal stent (3.4%) than in the plastic stent (14.8%) group (p < 0.0001). The rate of postoperative pancreatic fistula was significantly lower in the meta stent group as well (5.1% versus 11.8%, p = 0.04). The rate of post-operative surgical complications and of - post-operative mortality did not differ between the two groups. CONCLUSIONS: Although the present systematic review and meta-analysis demonstrates that metal stent are more effective than plastic stents for PBD in patients with resectable periampullary tumors, randomized controlled trials are needed in order to confirm these data with a higher level of evidence.