Locally advanced pancreatic head cancer: margin-positive resection or bypass?

Factors Predicting Response, Perioperative Outcomes, and Survival Following Total Neoadjuvant Therapy for Borderline/Locally Advanced Pancreatic Cancer

OBJECTIVE

To identify predictive factors associated with operative morbidity, mortality, and survival outcomes in patients with borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC) undergoing total neoadjuvant therapy (TNT).

BACKGROUND

The optimal preoperative treatment sequencing for BR/LA PDA is unknown. TNT, or systemic chemotherapy followed by chemoradiation (CRT), addresses both occult metastases and positive margin risks and thus is a potentially optimal strategy; however, factors predictive of perioperative and survival outcomes are currently undefined.

METHODS

We reviewed our experience in BR/LA patients undergoing resection from 2010 to 2017 following TNT assessing operative morbidity, mortality, and survival in order to define outcome predictors and response endpoints.

RESULTS

One hundred ninety-four patients underwent resection after TNT, including 123 (63%) BR and 71 (37%) LA PDAC. FOLFIRINOX or gemcitabine along with nab-paclitaxel were used in 165 (85%) and 65 (34%) patients, with 36 (19%) requiring chemotherapeutic switch before long-course CRT and subsequent resection. Radiologic anatomical downstaging was uncommon (28%). En bloc venous and/or arterial resection was required in 125 (65%) patients with 94% of patients achieving R0 margins. The 90-day major morbidity and mortality was 36% and 6.7%, respectively. Excluding operative mortalities, the median, 1-year, 2-year, and 3-year recurrence-free survival (RFS) [overall survival (OS)] rates were 23.5 (58.8) months, 65 (96)%, 48 (78)%, and 32 (62)%, respectively. Radiologic downstaging, vascular resection, and chemotherapy regimen/switch were not associated with survival. Only 3 factors independently associated with prolonged survival, including extended duration (≥6 cycles) chemotherapy, optimal post-chemotherapy CA19-9 response, and major pathologic response. Patients achieving all 3 factors had superior survival outcomes with a survival detriment for each failing factor. In a subset of patients with interval metabolic (PET) imaging after initial chemotherapy, complete metabolic response highly correlated with major pathologic response.

CONCLUSION

Our TNT experience in resected BR/LA PDAC revealed high negative margin rates despite low radiologic downstaging. Extended duration chemotherapy with associated biochemical and pathologic responses highly predicted postoperative survival. Potential modifications of initial chemotherapy treatment include extending cycle duration to normalize CA19-9 or achieve complete metabolic response, or consideration of chemotherapeutic switch in order to achieve these factors may improve survival before moving forward with CRT and subsequent resection.

Systematic Analysis of Accuracy in Predicting Complete Oncological Resection in Pancreatic Cancer Patients-Proposal of a New Simplified Borderline Resectability Definition

Background: Borderline resectability in pancreatic cancer (PDAC) is currently debated. Methods: Patients undergoing pancreatic resections for PDAC were identified from a prospectively maintained database. As new borderline criteria, the presence of any superior mesenterico-portal vein alteration (SMPV) and perivascular stranding of the superior mesenteric artery (SMA) was evaluated in preoperative imaging. The accuracy of established radiological borderline criteria as compared to the new borderline criteria in predicting R status (sensitivity/negative predictive value) and overall survival was assessed. (3) Results: 118 patients undergoing pancreatic resections for PDAC from 2013 to 2018 were identified. Forty-three (36.4%) had radiological perivascular SMA stranding and 55 (46.6%) had SMPV alterations. Interrater reliability was 90% for SMA stranding and 87% for SMPV alterations. The new borderline definition including SMPV alterations and perivascular SMA stranding was the best predictor of conventional R status (p = 0.040, sensitivity 53%, negative predictive value 81%) and Leeds/Wittekind circumferential margin status (p = 0.050, sensitivity 73%, negative predictive value 79%) as compared to established borderline resectability definition criteria. Perivascular SMA stranding qualified as an independent negative prognostic parameter (HR 3.066, 95% CI 1.078-5.716, p = 0.036). Conclusion: The radiological evaluation of any SMPV alteration and perivascular SMA stranding predicts R status and overall survival in PDAC patients, and may serve to identify potential candidates for neoadjuvant therapy.

Immune monitoring and TCR sequencing of CD4 T cells in a long term responsive patient with metastasized pancreatic ductal carcinoma treated with individualized, neoepitope-derived multipeptide vaccines: a case report

BACKGROUND

Cancer vaccines can effectively establish clinically relevant tumor immunity. Novel sequencing approaches rapidly identify the mutational fingerprint of tumors, thus allowing to generate personalized tumor vaccines within a few weeks from diagnosis. Here, we report the case of a 62-year-old patient receiving a four-peptide-vaccine targeting the two sole mutations of his pancreatic tumor, identified via exome sequencing.

METHODS

Vaccination started during chemotherapy in second complete remission and continued monthly thereafter. We tracked IFN-γ⁺ T cell responses against vaccine peptides in peripheral blood after 12, 17 and 34 vaccinations by analyzing T-cell receptor (TCR) repertoire diversity and epitope-binding regions of peptide-reactive T-cell lines and clones. By restricting analysis to sorted IFN-γ-producing T cells we could assure epitope-specificity, functionality, and T_H1 polarization.

RESULTS

A peptide-specific T-cell response against three of the four vaccine peptides could be detected sequentially. Molecular TCR analysis revealed a broad vaccine-reactive TCR repertoire with clones of discernible specificity. Four identical or convergent TCR sequences could be identified at more than one time-point, indicating timely persistence of vaccine-reactive T cells. One dominant TCR expressing a dual TCRVα chain could be found in three T-cell clones. The observed T-cell responses possibly contributed to clinical outcome: The patient is alive 6 years after initial diagnosis and in complete remission for 4 years now.

CONCLUSIONS

Therapeutic vaccination with a neoantigen-derived four-peptide vaccine resulted in a diverse and long-lasting immune response against these targets which was associated with prolonged clinical remission. These data warrant confirmation in a larger proof-of concept clinical trial.

Perioperative and long-term outcome after standard pancreaticoduodenectomy, additional portal vein and multivisceral resection for pancreatic head cancer

INTRODUCTION

The value of extended resection (portal vein, multivisceral) in patients with pancreatic adenocarcinoma (PDAC) is not well defined. We analyzed the outcome after standard resection (standard pancreaticoduodenectomy (SPR)), additional portal vein (PV) and multivisceral (MV) resection in PDAC patients.

METHODS

Clinicopathologic, perioperative, and survival data of patients undergoing pancreatic head resection (PHR) for PDAC 1994-2014 were reviewed from a prospective database.

RESULTS

Three hundred fifty nine patients had PHR for PDAC: 208 (58 %) underwent SPR, 131 (36 %) additional PV, and 20 (6 %) MV. The postoperative complication rate in MV (65 %) was slightly higher than in PV (56 %) or SPR (50 %; p = 0.32). MV patients had higher in-hospital mortality (10 %) than SPR (3.8 %) and PV (1.5 %) patients (p = 0.12). Nodal status was comparable, whereas more patients in PV and MV had final R0 resection (p = 0.02). Five-year survival was 7 % after MV versus 17 % in patients without MV (p = 0.07). Multivariate survival analysis identified resection margin, nodal disease, blood transfusions, and MV are set as independent risk factors for overall survival.

CONCLUSION

Multivisceral pancreatic head resections for PDAC are associated with increased perioperative morbidity and mortality, without improving oncologic outcome. Portal vein resection can be performed safely to reach R0 resection and its survival benefits.

Non-radical resection versus bypass procedure for pancreatic cancer - a consecutive series and systematic review

BACKGROUND

Most survival studies comparing non-radical resections to bypass surgery in patients with pancreatic cancer often do not differentiate between an R1 and R2 resection. The aim of this study was to evaluate whether non-radical R1 and R2 resections have better postoperative outcomes and survival compared to a palliative bypass.

METHODS

A single center cohort study was performed analyzing mortality, morbidity and 1-year survival after R1 (tumor cells within 1 mm from the circumferential margin), R2 and bypass surgery in patients with pancreatic cancer. For the systematic review, studies were identified comparing R1 or R2 resections with bypass, in patients with pancreatic cancer. Postoperative outcomes were compared including the cohort study.

RESULTS

The cohort study (n=405) showed higher morbidity rates after R1 (n=191) and R2 (n=11) resections compared to bypass (52% and 73% vs. 34%, p < 0.01). In-hospital mortality did not differ (overall 1.7%). 1-year survival rates were 71%, 46% and 32% after R1, R2 resection and bypass (p=0.6 between R2 and bypass). The systematic review identified 8 studies, after including the cohort study 1535 patients were analyzed. Increased morbidity after R1-R2 resection (48%) compared to bypass (30-34%) was found. Median survival was 14-18 months after R1 resection vs. 9-13 months after bypass and 8.5-11.5 months after R2 resection vs. 7.5-10.7 months after bypass.

CONCLUSION

An R2 resection should be avoided in patients with pancreatic cancer due to its poor prognosis. Survival benefit after an R1 resection, as compared to bypass surgery, justifies a resection despite the increased morbidity rate.

Portal vein resection in borderline resectable pancreatic cancer: a United Kingdom multicenter study

BACKGROUND

Until recently, in the United Kingdom, borderline resectable pancreatic cancer with invasion into the portomesenteric veins often resulted in surgical bypass because of the presumed high risk for complications and the uncertainty of a survival benefit associated with a vascular resection. Portomesenteric vein resection has therefore remained controversial. We present the second largest published cohort of patients undergoing portal vein resection for borderline resectable (T3) adenocarcinoma of the head of the pancreas.

STUDY DESIGN

This is a UK multicenter retrospective cohort study comparing pancreaticoduodenectomy with vein resection (PDVR), standard pancreaticoduodenectomy (PD), and surgical bypass (SB). Nine high-volume UK centers contributed. All consecutive patients with T3 (stage IIA to III) adenocarcinoma of the head of the pancreas undergoing surgery between December 1998 and June 2011 were included. The primary outcomes measures are overall survival and in-hospital mortality. Secondary outcomes measure is operative morbidity.

RESULTS

One thousand five hundred and eighty-eight patients underwent surgery for borderline resectable pancreatic cancer; 840 PD, 230 PDVR, and 518 SB. Of 230 PDVR patients, 129 had primary closure (56%), 65 had end to end anastomosis (28%), and 36 had interposition grafts (16%). Both resection groups had greater complication rates than the bypass group, but with no difference between PD and PDVR. In-hospital mortality was similar across all 3 surgical groups. Median survival was 18 months for PD, 18.2 months for PDVR, and 8 months for SB (p = 0.0001).

CONCLUSIONS

This study, the second largest to date on borderline resectable pancreatic cancer, demonstrates no significant difference in perioperative mortality in the 3 groups and a similar overall survival between PD and PDVR; significantly better compared with SB.