A transcriptomic signature to predict adjuvant gemcitabine sensitivity in pancreatic adenocarcinoma.

BACKGROUND: Chemotherapy is the only systemic treatment approved for pancreatic ductal adenocarcinoma (PDAC), with a selection of regimens based on patients' performance status and expected efficacy. The establishment of a potent stratification associated with chemotherapeutic efficacy could potentially improve prognosis by tailoring treatments. PATIENTS AND METHODS: Concomitant chemosensitivity and genome-wide RNA profiles were carried out on preclinical models (primary cell cultures and patient-derived xenografts) derived from patients with PDAC included in the PaCaOmics program (NCT01692873). The RNA-based stratification was tested in a monocentric cohort and validated in a multicentric cohort, both retrospectively collected from resected PDAC samples (67 and 368 patients, respectively). Forty-three (65%) and 203 (55%) patients received adjuvant gemcitabine in the monocentric and the multicentric cohorts, respectively. The relationships between predicted gemcitabine sensitivity and patients' overall survival (OS) and disease-free survival were investigated. RESULTS: The GemPred RNA signature was derived from preclinical models, defining gemcitabine sensitive PDAC as GemPred+. Among the patients who received gemcitabine in the test and validation cohorts, the GemPred+ patients had a higher OS than GemPred- (P = 0.046 and P = 0.00216). In both cohorts, the GemPred stratification was not associated with OS among patients who did not receive gemcitabine. Among gemcitabine-treated patients, GemPred+ patients had significantly higher OS than the GemPred-: 91.3 months [95% confidence interval (CI): 61.2-not reached] versus 33 months (95% CI: 24-35.2); hazard ratio 0.403 (95% CI: 0.221-0.735, P = 0.00216). The interaction test for gemcitabine and GemPred+ stratification was significant (P = 0.0245). Multivariate analysis in the gemcitabine-treated population retained an independent predictive value. CONCLUSION: The RNA-based GemPred stratification predicts the benefit of adjuvant gemcitabine in PDAC patients.

'Peripheric' pancreatic cysts: performance of CT scan, MRI and endoscopy according to final pathological examination.

OBJECTIVE: To assess the accuracy of pre-operative staging in patients with peripheral pancreatic cystic neoplasms (pPCNs). METHODS: From 2005 to 2011, 148 patients underwent a pancreatectomy for pPCNs. The pre-operative examination methods of computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) were compared for their ability to predict the suggested diagnosis accurately, and the definitive diagnosis was affirmed by pathological examination. RESULTS: A mural nodule was detected in 34 patients (23%): only 1 patient (3%) had an invasive pPCN at the final histological examination. A biopsy was performed in 79 patients (53%) during EUS: in 55 patients (70%), the biopsy could not conclude a diagnosis; the biopsy provided the correct and wrong diagnosis in 19 patients (24%) and 5 patients (6%), respectively. A correct diagnosis was affirmed by CT, EUS and pancreatic MRI in 60 (41%), 103 (74%) and 80 (86%) patients (when comparing EUS and MRI; P = 0.03), respectively. The positive predictive values (PPVs) of CT, EUS and MRI were 70%, 75% and 87%, respectively. CONCLUSIONS: Pancreatic MRI appears to be the most appropriate examination to diagnose pPCNs accurately. EUS alone had a poor PPV. Mural nodules in a PCN should not be considered an indisputable sign of pPCN invasiveness.

Resectable invasive IPMN versus sporadic pancreatic adenocarcinoma of the head of the pancreas: Should these two different diseases receive the same treatment? A matched comparison study of the French Surgical Association (AFC).

PURPOSE: To compare survival and impact of adjuvant chemotherapy in patients who underwent pancreaticoduodenectomy (PD) for invasive intraductal papillary mucinous neoplasm (IIPMN) and sporadic pancreatic ductal adenocarcinoma (PDAC). METHODS: From 2005 to 2012, 240 patients underwent pancreatectomy for IIPMN and 1327 for PDAC. Exclusion criteria included neoadjuvant treatment, pancreatic resection other than PD, vascular resection, carcinoma in situ, or <11 examined lymph nodes. Thus, 82 IIPMN and 506 PDAC were eligible for the present study. Finally, The IIPMN group was matched 1:2 to compose the PDAC group according to TNM disease stage, perineural invasion, lymph node ratio, and margin status. RESULTS: There was no difference in patient's characteristics, intraoperative parameters, postoperative outcomes, and histologic parameters. Overall survival and disease-free survival times were comparable between the 2 groups. In each group, overall survival time was significantly poorer in patients who did not achieve adjuvant chemotherapy (p = 0.03 for the IIPMN group; p = 0.03 for the PDAC group). In lymph-node negative patients of the IIPMN group, adjuvant chemotherapy did not have any significant impact on overall survival time (OR = 0.57; 95% CI [0.24-1.33]). Considering the whole population (i.e. patients with IIPMN and PDAC; n = 246), patients who did not achieve adjuvant chemotherapy had poorer survival (p < 0.01). CONCLUSIONS: The courses of IIPMN and PDAC were similar after an optimized stage-to-stage comparison. Adjuvant chemotherapy was efficient in both groups. However, in lymph node negative patients, adjuvant chemotherapy seemed not to have a significant impact.