To assess the relevance of resection margin status for survival outcome after resection and adjuvant therapy for pancreatic cancer. The definitions for R0 and R1 margin status after resection for pancreatic cancer are controversial. The strict definition of R0 requiring a 1 mm tumor-free margin is not commonly accepted. Reported R0/R1 rates and associated survival are highly heterogeneous. A standardized protocol with rigorous assessment of circumferential margins and the R0 definition with a 1 mm free margin were introduced into clinical routine in 2005. From a prospective database, patients undergoing pancreatoduodenectomy for pancreatic adenocarcinoma between January 1, 2006 and December 12, 2012 were identified. The rates of R0 (≥1 mm margin), R1 (<1 mm clearance), and R1 (direct margin involvement) status and associated survival were assessed by uni- and multivariable analyses. Of 561 patients included, 112 patients (20.0%) had R0 and 449 patients (80.0%) had R1 resections, including 123 (21.9%) R1 (≤1 mm) and 326 (58.1%) R1 (direct) resections. A total of 438 (85.9%) received adjuvant therapy. With R0, R1 (<1 mm), and R1 (direct) status the median survival times and 5-year survival rates were 41.6, 27.5, and 23.4 months; and 37.7%, 30.1%, and 20.3%, respectively (P < 0.0001). By multivariable analysis, margin status was confirmed to be independently associated with survival. In the context of adjuvant therapy, the resection margin status remains an important independent determinant of postresection survival. R0/R1 resection rates and associated survival vary significantly with the definitions used. An international consensus is urgently needed to achieve comparability with respect to studies and protocols on patients with adjuvant therapy.

To determine the prognostic value of PLN and LNR based on a large series with standardized lymphadenectomy and pathological workup. Lymph node (LN) involvement is a major prognostic factor in pancreatic adenocarcinoma. However, the distinction N0/N1 is not sufficient to accurately predict prognosis. To improve prognostic accuracy in N1 tumors, different LN parameters have been tested. Previous studies were based on series with variable numbers of examined lymph nodes (ELN) and came to inconsistent conclusions as to the value of the number of positive lymph nodes (PLN) and the lymph node ratio (LNR). 811 patients who underwent pancreatoduodenectomy for pancreatic adenocarcinoma between October 2001 and June 2012 were identified from a prospective database. Clinicopathological parameters included LN status (N0/N1), ELN, PLN, and LNR. Univariate and multivariate survival analyses were performed. The median number of ELN was 24 (interquartile range: 18-32). By univariate analysis, both PLN and LNR were significantly associated with survival in N1 tumors. However, by multivariate analysis, only the number of PLN was confirmed as independent predictor of survival. Median survival in patients with only 1 PLN was 31.1 months and comparable to the survival in N0 (33.2 months). With increasing numbers of PLN median survival significantly decreased (2-3 PLN: 26.1 months, 4-7 PLN: 21.9 months, ≥8 PLN: 18.3 months, P < 0.0001). This study demonstrates that, based on high numbers of ELN, PLN is superior to LNR in predicting survival and allows to distinguish several N-categories that improve prognostic accuracy in LN-positive resectable pancreatic adenocarcinoma.

In the past decade, the use of neoadjuvant treatment (NAT) has markedly increased for patients with borderline resectable and locally advanced pancreatic ductal adenocarcinoma (PDAC).¹ This increase has enabled a large number of patients whose tumors were considered inoperable in the past to undergo pancreatic resection,² and several studies have shown encouraging surgical outcomes,^2-4 as well as improvement in pathologic findings.^5,6

Objective: To evaluate the impact of clinical and pathological parameters, including resection margin (R) status, on survival in patients undergoing pancreatic surgery after neoadjuvant treatment for initially unresectable pancreatic ductal adenocarcinoma (PDAC). Background: Prognostic factors are well documented for patients with resectable PDAC, but have not been described in detail for patients with initially unresectable PDAC undergoing resection after neoadjuvant therapy. Methods: Prospectively collected data of consecutive patients with initially unresectable pancreatic cancer treated by neoadjuvant treatment and resection were analyzed. The R status was categorized as R0 (tumor-free margin >1 mm), R1 ≤1 mm (tumor-free margin ≤1 mm), and R1 direct (microscopic tumor infiltration at margin). Clinicopathological characteristics and outcomes were compared among these groups and tested for survival prediction. Results: Between January, 2006 and February, 2017, 280 patients with borderline resectable (n = 18), locally advanced (n = 190), or oligometastatic (n = 72) disease underwent tumor resection after neoadjuvant treatment. Median overall survival from the time of surgery was 25.1 months for R0 (n = 82), 15.3 months for R1 ≤1 mm (n = 99), and 16.1 months for R1 direct (n = 99), with 3-year overall survival rates of 35.0%, 20.7%, and 18.5%, respectively (P = 0.0076). The median duration of the neoadjuvant treatment period was 5.1 months. In multivariable analysis, preoperative CA 19–9 levels, lymph node status, metastasis category, and vascular involvement were all significant prognostic factors for overall survival. The R status was not an independent prognostic factor. Conclusions: In patients undergoing resection after neoadjuvant therapy for initially unresectable PDAC, preoperative CA 19–9 levels, lymph node involvement, metastasis category, and vascular involvement, but not the R status, were independent prognostic factors of overall survival.

Purpose: The devastating prognosis of patients with resectable pancreatic ductal adenocarcinoma (PDA) presents an urgent need for the development of therapeutic strategies targeting disseminated tumor cells. Until now, T-cell therapy has been scarcely pursued in PDA, due to the prevailing view that it represents a poorly immunogenic tumor. Experimental design: We systematically analyzed T-cell infiltrates in tumor biopsies from 127 patients with resectable PDA by means of immunohistochemistry, flow cytometry, T-cell receptor (TCR) deep-sequencing and functional analysis of in vitro expanded T-cell cultures. Parallel studies were performed on tumor-infiltrating lymphocytes (TIL) from 44 patients with metastatic melanoma. Results: Prominent T-cell infiltrates, as well as tertiary lymphoid structures harboring proliferating T-cells, were detected in the vast majority of biopsies from PDA patients. The notion that the tumor is a site of local T-cell expansion was strengthened by TCR deep-sequencing, revealing that the T-cell repertoire in the tumor is dominated by highly frequent CDR3 sequences that can be up to 10,000-fold enriched in tumor as compared to peripheral blood. In fact, TCR repertoire composition in PDA resembled that in melanoma. Moreover, in vitro expansion of TILs was equally efficient for PDA and melanoma, resulting in T-cell cultures displaying HLA class I-restricted reactivity against autologous tumor cells. Conclusions: The tumor-infiltrating T-cell response in PDA shows striking similarity to that in melanoma, where adoptive T-cell therapy has significant therapeutic impact. Our findings indicate that T-cell-based therapies may be used to counter disease recurrence in patients with resectable PDA.