New study suggests some pancreatic cancers may be more susceptible to immunotherapy than previously thought

Pancreatic cancer is an aggressive type of cancer, and most patients have few options for effective treatment.

Immunotherapies—a group of treatment approaches that leverage a person's own immune system to fight their cancer—can work remarkably well for some people with various cancer types.

Despite their promise, immunotherapies have not, so far, been generally effective against pancreatic cancer. This is thought to be due to pancreatic cancers being “immunologically cold”, meaning that they do not contain many immune cells.

A new study by Network researchers at Dalhousie University challenges this idea and suggests that immunotherapy could be beneficial for at least a subset of people with pancreatic cancer. The study was funded in part by a MOHCCN Health Informatics & Data Science Award granted to PhD candidate Riley Arseneau, who is lead author on the study.

Published in the journal Frontiers in Immunology, the study uses a technique called multiplex immunofluorescence to show that immune cells are present in pancreatic tumours, but inconsistently distributed.

The team—led by Dr. Jeanette Boudreau—developed new algorithms to classify and describe different patterns of immune cells within these tumours, and looked at correlations between those patterns and patient outcomes. They found that specific patterns of immune cells, along with the location of these patterns, were associated with better patient outcomes.

“We have shown that immune cell configuration—not just immune cell presence—in pancreatic tumours can help predict survival,” says team lead Dr. Jeanette Boudreau. “This kind of information can help patients in their decision-making and determine care goals.”

The spatial distribution of immune cells in tumours has important implications for immunotherapies, since immune-mediated tumour killing generally requires physical contact between tumour cells and specific types of immune cells.

The findings from this study provide a first step for understanding how immune cells function in pancreatic tumours, how this can be leveraged to optimize conditions for immunotherapy, and who is most likely to benefit from these kinds of treatment approaches.

The team is now doing follow-up studies to understand how and where immune cells infiltrate within these tumours, and whether genetic mutations might predict specific immune landscapes in individual patients. This ongoing work is made possible in part because the patients profiled for this study are also part of the MOHCCN Gold Cohort; therefore, their tumour samples have also undergone genetic sequencing.

“We think our findings reflect an ongoing activation of immune cells within pancreatic tumours,” says Arseneau. “This is a change in paradigm for this cancer type, and provides optimism that immune-mediated control of pancreatic cancer is possible.”

The Health Informatics & Data Science Award received by Arseneau helped increase the scale of the study, allowing the team to profile tumours from 73 patients and providing a broader view of the different immune patterns found across pancreatic cancers than would otherwise have been possible.

The award also had important impacts on Arseneau’s training. “Throughout this study, I’m grateful to have had the opportunity to learn new techniques and work with an interdisciplinary team of pathologists, immunologists and clinical bioinformaticians—all leading Canadian researchers in precision oncology,” says Arseneau.

“Not only is this work helping to solidify collaborations within our interdisciplinary group, but it is also enriching Riley’s training in myriad ways and equipping her as a future leader in the Canadian cancer research landscape,” says Dr. Boudreau.

Study

Riley J. Arseneau, Jorge P. Mejia, Sarah Nersesian, Stacey N. Lee, Carley Bekkers, Thomas Samson, Daniel Gaston, Boris L. Gala-Lopez, Ravi Ramjeesingh, Thomas Arnason & Jeanette E. Boudreau. Peri-tumoural lymphocyte neighbourhoods predict longer survival in pancreatic ductal adenocarcinoma (2025) Frontiers in Immunology 16: 1730817. doi: 10.3389/fimmu.2025.1730817

Funding

This study was funded in part by a MOHCCN Health Informatics & Data Science award granted to Riley Arseneau. Sequencing of patient samples for this study was partially funded by the Marathon of Hope Cancer Centres Network. These samples are now part of the MOHCCN Gold Cohort, which means that in the future, other researchers may use these data to further their precision medicine studies. 

This study was also made possible by the Canadian Cancer Society, JD Irving Atlantic Canada, GIVETOLIVE, the Kilpatrick Trust, the Rick Salsman Pancreatic Cancer Studentship Fund, and Dalhousie University.