Increasing Systemic Immune-inflammation Index During Treatment in Patients With Advanced Pancreatic Cancer is Associated With Poor Survival: A Retrospective, Multicenter, Cohort Study

BACKGROUND AND OBJECTIVES

A high systemic immune-inflammation index (SIII) at diagnosis of various cancers, including pancreatic cancer, is associated with poor prognosis. The impact of FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) chemotherapy or stereotactic body radiotherapy on this index is unknown. In addition, the prognostic value of changes in the SIII during treatment is unclear. In this retrospective analysis, we aimed to find answers regarding patients with advanced pancreatic cancer.

METHODS

Patients with advanced pancreatic cancer treated with FOLFIRINOX chemotherapy alone or with FOLFIRINOX chemotherapy followed by stereotactic body radiotherapy between 2015 and 2021 in 2 tertiary referral centers were included. Baseline characteristics, laboratory values at 3 time points during treatment, and survival outcomes were collected. The patient-specific evolutions of SIII and their association with mortality were assessed with joint models for longitudinal and time-to-event data.

RESULTS

Data of 141 patients were analyzed. At a median follow-up time of 23.0 months (95% CI: 14.6-31.3), 97 (69%) patients had died. Median overall survival was 13.2 months (95% CI: 11.0-15.5). During treatment with FOLFIRINOX, the log (SIII) was reduced by -0.588 (95% CI: -0.0978, -0.197; P = 0.003). One unit increase in log (SIII) increased the hazard ratio of dying by 1.604 (95% CI: 1.068-2.409; P = 0.023).

CONCLUSIONS

In addition to carbohydrate antigen 19-9, the SIII is a reliable biomarker in patients with advanced pancreatic cancer.

B cell immune profiles in dysbiotic vermiform appendixes of pancreatic cancer patients

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest solid tumors and is resistant to immunotherapy. B cells play an essential role in PDAC progression and immune responses, both locally and systemically. Moreover, increasing evidence suggests that microbial compositions inside the tumor, as well as in the oral cavity and the gut, are important factors in shaping the PDAC immune landscape. However, the gut-associated lymphoid tissue (GALT) has not previously been explored in PDAC patients. In this study, we analyzed healthy vermiform appendix (VA) from 20 patients with PDAC and 32 patients with colon diseases by gene expression immune profiling, flow cytometry analysis, and microbiome sequencing. We show that the VA GALT of PDAC patients exhibits markers of increased inflammation and cytotoxic cell activity. In contrast, B cell function is decreased in PDAC VA GALT based on gene expression profiling; B cells express significantly fewer MHC class II surface receptors, whereas plasma cells express the immune checkpoint molecule HLA-G. Additionally, the vermiform appendix microbiome of PDAC patients is enriched with Klebsiella pneumoniae, Bifidobacterium animalis, and Adlercreutzia equolifaciens, while certain commensals are depleted. Our findings may suggest impaired B cell function within the GALT of PDAC patients, which could potentially be linked to microbial dysbiosis. Additional investigations are imperative to validate our observations and explore these potential targets of future therapies.

Sex, Gender and Age Differences in Treatment Allocation and Survival of Patients With Metastatic Pancreatic Cancer: A Nationwide Study

Background

Biological sex, gender and age have an impact on the incidence and outcome in patients with metastatic pancreatic cancer. The aim of this study is to investigate whether biological sex, gender and age are associated with treatment allocation and overall survival (OS) of patients with metastatic pancreatic cancer in a nationwide cohort.

Methods

Patients with synchronous metastatic pancreatic cancer diagnosed between 2015 and 2019 were selected from the Netherlands Cancer Registry (NCR). The association between biological sex and the probability of receiving systemic treatment were examined with multivariable logistic regression analyses. Kaplan Meier analyses with log-rank test were used to describe OS.

Results

A total of 7470 patients with metastatic pancreatic cancer were included in this study. Fourty-eight percent of patients were women. Women received less often systemic treatment (26% vs. 28%, P=0.03), as compared to men. Multivariable logistic regression analyses with adjustment for confounders showed that women ≤55 years of age, received more often systemic treatment (OR 1.82, 95% CI 1.24-2.68) compared to men of the same age group. In contrast, women at >55 years of age had a comparable probability to receive systemic treatment compared to men of the same age groups. After adjustment for confounders, women had longer OS compared to men (HR 0.89, 95% CI 0.84-0.93).

Conclusion

This study found that women in general had a lower probability of receiving systemic treatment compared to men, but this can mainly be explained by age differences. Women had better OS compared to men after adjustment for confounders.

Organoids Derived from Neoadjuvant FOLFIRINOX Patients Recapitulate Therapy Resistance in Pancreatic Ductal Adenocarcinoma

PURPOSE

We investigated whether organoids can be generated from resected tumors of patients who received eight cycles of neoadjuvant FOLFIRINOX chemotherapy before surgery, and evaluated the sensitivity/resistance of these surviving cancer cells to cancer therapy.

EXPERIMENTAL DESIGN

We generated a library of 10 pancreatic ductal adenocarcinoma (PDAC) organoid lines: five each from treatment-naïve and FOLFIRINOX-treated patients. We first assessed the histologic, genetic, and transcriptional characteristics of the organoids and their matched primary PDAC tissue. Next, the organoids' response to treatment with single agents-5-FU, irinotecan, and oxaliplatin-of the FOLFIRINOX regimen as well as combined regimen was evaluated. Finally, global mRNA-seq analyses were performed to identify FOLFIRINOX resistance pathways.

RESULTS

All 10 patient-derived PDAC organoids recapitulate histologic, genetic, and transcriptional characteristics of their primary tumor tissue. Neoadjuvant FOLFIRINOX-treated organoids display resistance to FOLFIRINOX (5/5), irinotecan (5/5), and oxaliplatin (4/5) when compared with treatment-naïve organoids (FOLFIRINOX: 1/5, irinotecan: 2/5, oxaliplatin: 0/5). 5-Fluorouracil treatment responses between naïve and treated organoids were similar. Comparative global transcriptome analysis of treatment-naïve and FOLFIRINOX samples-in both organoids and corresponding matched tumor tissues-uncovered modulated pathways mainly involved in genomic instability, energy metabolism, and innate immune system.

CONCLUSIONS

Resistance development in neoadjuvant FOLFIRINOX organoids, recapitulating their primary tumor resistance, suggests continuation of FOLFIRINOX therapy as an adjuvant treatment may not be advantageous for these patients. Gene-expression profiles of PDAC organoids identify targetable pathways involved in chemoresistance development upon neoadjuvant FOLFIRINOX treatment, thus opening up combination therapy possibilities.

Abstract B37: The complex immune-microenvironment heterogeneity in pancreatic cancer

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy, resulting in more than 3,000 deaths per year in The Netherlands. The tumor microenvironment (TME) contributes largely to the treatment failure of the disease. TME consists of the stromal compartment, extracellular matrix, and tumor-infiltrative lymphocytes (TILs). Types and numbers of TILs are associated with clinical outcome, i.e., highCD8+: FOXP3 ratio is linked to a favorable prognosis. However, the intratumor immune variation in pancreatic cancer has not been studied so far. This study aims at investigating the differences of the immune infiltration within various areas of the same pancreatic cancer samples (intratumor variation) and comparing to healthy controls (extratumor variation). Such differences may be used for microenvironment remodeling, which may open new therapeutic approaches for PDAC patients.

Materials and Methods: Formalin-fixed, paraffin-embedded (FFPE) samples of 26 PDAC patients and 8 healthy controls were selected. RNA was isolated separately from the tumor core and from the adjacent normal-like pancreatic tissue of the same sample. Immune profiling was carried out using the PanCancer Immune Profiling Panel of Nanostring technology. Subsequently, the gene expression data were analyzed using nSolver basic software and the advanced module.

Results: The immune infiltration in the core of PDAC samples was different from that in the adjacent normal-like areas of the same patients. Tumor samples exhibited the lowest CD8+, Th1, neutrophil, and Natural Killer cell infiltration as compared to normal-like areas. In addition, the normal-like areas of PDAC samples showed a different immune profile as compared to the healthy controls. B lymphocytes were significantly higher in healthy controls compared to normal-like PDAC samples.

Discussion and Conclusion: Our results present the variation in the immune microenvironment between the normal-like pancreatic tissue and the healthy pancreas, indicating that changes at the immune levels precede morphologic changes, tumorigenesis, and tumor cell infiltration. Additionally, specific changes in TILs occur in a gradient fashion from adjacent normal-like tissue to the tumor core. Understanding the differences of the immune microenvironment in the same tissue samples will enable developing an accurate microenvironment remodeling therapeutic approaches to treat PCDA patients.

Citation Format: Frederieke Grevers, Diba Latifi, Willem de Koning, Casper H.J. van Eijck, Dana A. Mustafa. The complex immune-microenvironment heterogeneity in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B37.

Efficacy and feasibility of stereotactic radiotherapy after folfirinox in patients with locally advanced pancreatic cancer (LAPC-1 trial)

BACKGROUND

We conducted a multicentre phase II trial to investigate feasibility and antitumor activity of sequential FOLFIRINOX and Stereotactic Body Radiotherapy (SBRT) in patients with locally advanced pancreatic cancer (LAPC), (LAPC-1 trial).

METHODS

Patients with biopsy-proven LAPC treated in four hospitals in the Netherlands between December 2014 and June 2017. Patients received 8 cycles of FOLFIRINOX followed by SBRT (5 fractions/8 Gy) if no tumour progression after the FOLFIRINOX treatment was observed. Primary outcome was 1-year overall survival (OS). Secondary outcomes were median OS, 1-year progression-free survival (PFS), treatment-related toxicity, and resection rate. The study is registered with ClinicalTrials.gov, NCT02292745, and is completed.

FINDINGS

Fifty patients were included. Nineteen (38%) patients did not receive all 8 cycles of FOLFIRINOX, due to toxicity (n = 12), disease progression (n = 6), or patients' preference (n = 1). Thirty-nine (78%) patients received the SBRT treatment. The 1-year OS and PFS were 64% (95% CI: 50%-76%) and 34% (95% CI: 22%-48%), respectively. Thirty grade 3 or 4 adverse events were observed during FOLFIRINOX. Two (5%) grade 3 or 4 adverse events after SBRT were observed. Two (5%) patients died due to a gastro-intestinal bleeding within three months after SBRT were observed. Six (12%) patients underwent a resection, all resulting in a complete (R0) resection. Two patients had a complete pathological response.

INTERPRETATION

FOLFIRINOX followed by SBRT in patients with LAPC is feasible and shows relevant antitumor activity. In 6 (12%) patients a potentially curative resection could be pursued following this combined treatment, with a complete histological response being observed in two patients.

Effect of targeting CD40 for DC vaccination in pancreatic adenocarcinoma

e15783

Background: Although immunotherapy yields striking results in various malignancies, results in pancreatic cancer have been disappointing. Both a highly immunosuppressive tumor microenvironment and a dense desmoplastic stroma have been found to prohibit proper T-cell infiltration in these tumors, thereby preventing immunotherapy efficacy. We hypothesize that a rational and translational multistep approach is needed to sensitize pancreatic cancer to immunotherapy. In an aggressive murine pancreatic ductal adenocarcinoma model, we assessed the effectiveness of dendritic cell (DC) vaccination in combination with αCD40 treatment, as these treatments are known to induce effector T cells and degrade stroma, respectively. Methods: Immune competent C57BL/6 mice were inoculated subcutaneously with pancreatic tumor cells (KPC3). Mice with established tumors were vaccinated with tumor-loaded monocyte derived DCs and consequently treated with αCD40 agonistic antibodies. Tumor sizes were monitored over time. Immune responses were determined by flow cytometry of cells in peripheral blood, spleen and tumor. NanoString Technologies were applied on tumor samples. Results: A significant delay in tumor growth was found in the combination therapy arm compared to untreated mice and mice treated with DCs or αCD40 alone. Monotherapy had no effect on tumor growth. Survival of mice treated with the combination therapy was also improved compared to untreated mice or mice treated with monotherapy (P < 0.001). Interim blood analysis showed significant increases in frequencies of activated and proliferating T cells in treated animals and those cells also displayed an effector memory phenotype. This was more pronounced for CD4 T cells in mice treated with DCs while αCD40 therapy induced a confined response in CD8 T cells. Increased frequencies of tumor infiltrating lymphocytes were found in all treated mice compared to untreated mice. mRNA expression analysis indicated less exhausted phenotype of intratumoral lymphoid cells in mice treated with DCs and αCD40 compared to monotherapy DCs or αCD40. Conclusions: These results demonstrate the potency of this novel form of combination immunotherapy and reveals a mechanistic insight into the requirements of effective immunotherapy in pancreatic cancer.

Preoperative chemoradiotherapy versus immediate surgery for resectable and borderline resectable pancreatic cancer (PREOPANC-1): A randomized, controlled, multicenter phase III trial

LBA4002

Background: Standard of care for patients with (borderline) resectable pancreatic adenocarcinoma is resection followed by adjuvant chemotherapy. Previous studies suggest a benefit of neoadjuvant treatment. We conducted a multicenter phase III randomized controlled trial to evaluate the effect of preoperative chemoradiotherapy. Methods: Patients with (borderline) resectable pancreatic cancer, pathologically confirmed, were randomized between immediate surgery (arm A) and preoperative chemoradiotherapy (arm B), both followed by adjuvant chemotherapy. The preoperative chemoradiotherapy consisted of 15 times of 2.4 Gray (Gy) combined with gemcitabine, 1,000 mg/m2 on days 1, 8 and 15, preceded and followed by a cycle of gemcitabine. Primary endpoint was overall survival (OS), secondary endpoints were (R0) resection rate, disease free survival (DFS), distant metastases free interval (DMFI), locoregional recurrence free interval (LRFI) and toxicity. Accrual was completed between April 23, 2013 and July 25, 2017. Results: In total, 246 patients were included in the intention-to-treat analysis (127 patients in arm A and 119 in arm B). Currently, 142 of the 176 needed events for the primary outcome are observed. OS was significantly better in arm B (median 13.5 vs. 17.1 months; HR 0.71; p = 0.047). This was also the case for R0 resection rate (31% vs. 65%, p = < 0.001), DFS (median 7.9 vs. 11.2 months; HR 0.67; p = 0.010), DMFI (median 10.2 vs 17.1 months; HR 0.63; p = 0.012) and LRFI (median 11.8 vs not reached; HR 0.47; p < 0.001). Resection rates were 72% (91/127) in arm A vs. 62% (74/119) in arm B (p = 0.15). No significant difference was observed in grade ≥ 3 adverse events between both groups (p = 0.17). A subgroup analysis of patients who actually underwent a resection was performed which showed a median OS of 16.8 and 29.9 months respectively (p < 0.001). Conclusion: Our preliminary data show that preoperative chemoradiotherapy significantly improves outcome in (borderline) resectable pancreatic cancer compared to immediate surgery. Updated results will be presented at the meeting. Clinical trial information: NTR3709.

Potentiation of Peptide Receptor Radionuclide Therapy by the PARP Inhibitor Olaparib

Metastases expressing tumor-specific receptors can be targeted and treated by binding of radiolabeled peptides (peptide receptor radionuclide therapy or PRRT). For example, patients with metastasized somatostatin receptor-positive neuroendocrine tumors (NETs) can be treated with radiolabeled somatostatin analogues, resulting in strongly increased progression-free survival and quality of life. There is nevertheless still room for improvement, as very few patients can be cured at this stage of disease. We aimed to specifically sensitize replicating tumor cells without further damage to healthy tissues. Thereto we investigated the DNA damaging effects of PRRT with the purpose to enhance these effects through modulation of the DNA damage response. Although PRRT induces DNA double strand breaks (DSBs), a larger fraction of the induced lesions are single strand breaks (expected to be similar to those induced by external beam radiotherapy) that require poly-[ADP-ribose]-polymerase 1 (PARP-1) activity for repair. If these breaks cannot be repaired, they will cause replication fork arrest and DSB formation during replication. Therefore, we used the PARP-1 inhibitor Olaparib to increase the number of cytotoxic DSBs. Here we show that this new combination strategy synergistically sensitized somatostatin receptor expressing cells to PRRT. We observed increased cell death and reduced cellular proliferation compared to the PRRT alone. The enhanced cell death was caused by increased numbers of DSBs that are repaired with remarkably slow kinetics, leading to genome instability. Furthermore, we validated the increased DSB induction after PARP inhibitor addition in the clinically relevant model of living human NET slices. We expect that this combined regimen can thus augment current PRRT outcomes.

Prognostic value of lymph node metastases detected during surgical exploration for pancreatic or periampullary cancer: a systematic review and meta-analysis

BACKGROUND

Hepatic-artery and para-aortic lymph node metastases (LNM) may be detected during surgical exploration for pancreatic (PDAC) or periampullary cancer. Some surgeons will continue the resection while others abort the exploration.

METHODS

A systematic search was performed in PubMed, EMBASE and Cochrane Library for studies investigating survival in patients with intra-operatively detected hepatic-artery or para-aortic LNM. Survival was stratified for node positive (N1) disease.

RESULTS

After screening 3088 studies, 13 studies with 2045 patients undergoing pancreatoduodenectomy were included. No study reported survival data after detection of LNM and aborted surgical exploration. In 110 patients with hepatic-artery LNM, median survival ranged between 7 and 17 months. Estimated pooled mean survival in 84 patients with hepatic-artery LNM was 15 [95%CI 12-18] months (13 months in PDAC), compared to 19 [16-22] months in 270 patients with N1-disease without hepatic-artery LNM (p = 0.020). In 192 patients with para-aortic LNM, median survival ranged between 5 and 32 months. Estimated pooled mean survival in 169 patients with para-aortic LNM was 13 [8-17] months (11 months in PDAC), compared to 17 (6-27) months in 506 patients with N1-disease without para-aortic LNM (p < 0.001). Data on the impact of (neo)adjuvant therapy on survival were lacking.

CONCLUSION

Survival after pancreatoduodenectomy in patients with intra-operatively detected hepatic-artery and especially para-aortic LNM is inferior to patients undergoing pancreatoduodenectomy with other N1 disease. It remains unclear what the consequence of this should be since data on (neo-)adjuvant therapy and survival after aborted exploration are lacking.