Neoadjuvant and adjuvant chemotherapy in pancreatic cancer

Adjuvant chemotherapy after surgery for pancreatic ductal adenocarcinoma: retrospective real-life data

BACKGROUND

The recommendation for postoperative chemotherapy in pancreatic ductal adenocarcinoma (PDAC) is based on prospective randomized trials. However, patients included in clinical trials do not often reflect the overall patient population treated in clinical practice.

MATERIALS AND METHODS

A retrospective review of all patients undergoing pancreas resection for PDAC between 2001 and 2013 was performed. Follow-up data from oncologists, general practitioners, or hospital patient files were available for 92% of patients.

RESULTS

A total of 251 patients were included in our analysis. Chemotherapy was recommended for 223 patients, but 86 patients did not follow the recommendation. The application of the recommended chemotherapy, consisting of 6 cycles of gemcitabine, was only applied to 45 patients. Forty patients received the recommended number of cycles with dose reduction or prolonged intervals between cycles, and adjuvant chemotherapy was terminated prior to the intended completion of all 6 cycles in 54 patients. Survival of patients after adjuvant chemotherapy was increased compared to that of patients without chemotherapy (with recurrence 25.6 vs. 14.3 months, p = 0.001, and without recurrence 27.4 vs. 14.3 months, p <  0.001). Terminating chemotherapy prior to completion (p = 0.009) as well as a lower number of chemotherapy cycles (p = 0.026) was associated with a decreased survival.

CONCLUSION

Adjuvant chemotherapy improves overall and disease-free survival after curative pancreatic resection, but only a small fraction of patients completes the recommended 6 cycles of adjuvant chemotherapy. Our data indicates that performance status of patients after pancreas resections for PDAC requires not only highly biologically active but also well-tolerated adjuvant chemotherapy regimens.

PACAP and PAC1 receptor expression in pancreatic ductal carcinoma

Pancreatic carcinoma is one of the most malignant diseases and is associated with a poor survival rate. Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide that acts on three different G protein-coupled receptors: the specific PAC1 and the VPAC1/2 that also bind vasoactive intestinal peptide. PACAP is widely distributed in the body and has diverse physiological effects. Among other things, it acts as a trophic factor and influences proliferation and differentiation of several different cells both under normal circumstances and tumourous transformation. Changes of PACAP and its receptors have been shown in various tumour types. However, it is not known whether PACAP and its specific receptor are altered in pancreatic cancer. Perioperative data of patients with pancreas carcinoma was investigated over a five-year period. Histological results showed Grade 2 or Grade 3 adenocarcinoma in most cases. PACAP and PAC1 receptor expression were investigated by immunohistochemistry. Staining intensity of PAC1 receptor was strong in normal tissues both in the exocrine and endocrine parts of the pancreas, the receptor staining was markedly weaker in the adenocarcinoma. PACAP immunostaining was weak in the exocrine part and very strong in the islets and nerve elements in non-tumourous tissues. The PACAP immunostaining almost disappeared in the adenocarcinoma samples. Based on these findings a decrease or lack of the PAC1 receptor/PACAP signalling might have an influence on tumour growth and/or differentiation.

Opinions and use of neoadjuvant therapy for resectable, borderline resectable, and locally advanced pancreatic cancer: international survey and case-vignette study

BACKGROUND

Several new treatment options have become available for pancreatic ductal adenocarcinoma (PDAC), but the support for their use for resectable, borderline resectable and locally advanced PDAC is unclear.

METHODS

A survey was distributed to the members of the European-African Hepato-Pancreato Biliary Association (E-AHPBA) and the pancreas group of the European Organization for Research and Treatment of Cancer (EORTC) regarding 1) definitions of local resectability, 2) indications for neoadjuvant therapy and 3) case-vignettes regarding the resectability and treatment of PDAC.

RESULTS

In total, 114 participants from 37 countries were registered. About 35% of respondents, each, were of the opinion that borderline resectability is defined by any venous tumor contact and venous involvement < 180° or > 180°, respectively. The majority (75.4%) of participants believed that borderline resectable PDAC has a high risk for R1 resection and that neoadjuvant therapy might increase the R0-resection rate (79.8%) and improve oncological patient selection (84.2%). Chemotherapy was regarded useful to convert locally advanced to resectable PDAC by 55.7% of respondents. In the cases with resectable, borderline resectable, and locally advanced PDAC, 10 (8.8%), 78 (68.4%), 55 (48.2%) of participants would start with chemotherapy, respectively.

CONCLUSIONS

Although definitions for borderline resectability differ among European surgeons, there seems to be a rather strong support for preoperative chemotherapy in PDAC aiming at minimizing R1 resections while increasing resection rates.

Modified FOLFIRINOX for resected pancreatic cancer: Opportunities and challenges

Pancreatic cancer is one of the leading causes of cancer death worldwide. Adjuvant chemotherapy has been developed based on the experiences made with palliative chemotherapy, and advocated to improve long-term survival of patients with this disease. However, the optimal chemotherapeutic regimen remains controversial. Recently, Conroy et al demonstrated the impressive benefits of modified FOLFIRINOX over gemcitabine alone in the multicenter Partenariat de Recherche en Oncologie Digestive 24 (PRODIGE-24) trial. The remarkable results mark a new milestone in treating resectable pancreatic cancer and have now changed the standard of care for this patient population. In this commentary, we discuss an issue of difference of tumor grade between the PRODIGE-24 trial and previous phase III trials. We also discuss potential biomarkers predicting therapeutic response to modified FOLFIRINOX. Finally, we summarize several ongoing clinical trials of replacing part of the FOLFIRINOX regimen with Xeloda/S-1/nanoliposomal irinotecan for pancreatic cancer.

Adjuvant treatment for pancreatic cancer

Pancreatic cancer is the third leading cause of cancer-associated mortality in Western countries. Upfront resection with adjuvant chemotherapy is the treatment of choice in resectable tumors, offering the chance for cure. Until the 1990s, adjuvant therapy was not routinely used after resection for pancreatic cancer. During the last three decades however, enormous progress has been made in evidence-based onco-surgical management of resectable pancreatic cancer. Based on the results from multicenter randomized controlled trials, primarily initiated by the European Study Group of Pancreatic Cancer (ESPAC), adjuvant chemotherapy has become the gold standard after upfront resection, while adjuvant chemoradiotherapy is not recommended. Combination chemotherapy with gemcitabine and capecitabine was shown to significantly prolong median overall survival after resection compared to monotherapy with either gemcitabine or 5-fluorouracil/folinic acid. Recent data from the French-Canadian Uni-Cancer GI PRODIGE 24/CCTG PA.6 trial showed that adjuvant poly-agent chemotherapy with modified FOLFIRINOX achieved median survival times of 54.4 months in selected patients. Despite improved survival times after resection followed by adjuvant chemotherapy, however, recurrence occurs still in more than 75% of patients within the first 2 years after resection. Further efforts are therefore to be made in early detection tools, the evaluation of neoadjuvant strategies, the development of new drug targets, and stratification strategies to better select patients for the available therapies. This review article summarizes the body of evidence on adjuvant treatment for pancreatic cancer, identifies evidence gaps and provides future perspectives.

STING agonist inflames the pancreatic cancer immune microenvironment and reduces tumor burden in mouse models

Pancreatic cancer is characterized by an immune suppressive stromal reaction that creates a barrier to therapy. A murine transgenic pancreatic cancer cell line that recapitulates human disease was used to test whether a STimulator of Interferon Genes (STING) agonist could reignite immunologically inert pancreatic tumors. STING agonist treatment potently changed the tumor architecture, altered the immune profile, and increased the survival of tumor-bearing mice. Notably, STING agonist increased numbers and activity of cytotoxic T cells within tumors and decreased levels of suppressive regulatory T cells. Further, STING agonist treatment upregulated costimulatory molecule expression on cross-presenting dendritic cells and reprogrammed immune-suppressive macrophages into immune-activating subtypes. STING agonist promoted the coordinated and differential cytokine production by dendritic cells, macrophages, and pancreatic cancer cells. Cumulatively, these data demonstrate that pancreatic cancer progression is potently inhibited by STING agonist, which reignited immunologically cold pancreatic tumors to promote trafficking and activation of tumor-killing T cells.