Breakthrough Study Reveals Why Pancreatic Cancer Is So Hard to Treat and How New Therapies Could Change Outcomes

Pancreatic cancer remains one of the most challenging cancers to treat, often developing silently for years before symptoms appear. Even after surgical removal of a tumor, hidden cancer cells can later resurface, leading to recurrence. Researchers at the University of Rochester Medicine have now uncovered critical clues about this evasive behavior, offering hope for more effective therapies.

The study, published in the journal Developmental Cell, highlights the role of a previously understudied gene called Dec2. This gene helps pancreatic cancer cells disguise themselves from the immune system’s killer T cells, which normally seek and destroy cancer cells. By regulating a molecule on the surface of tumor cells, Dec2 allows cancer to evade detection.

“Pancreatic cancer is an urgent problem, with a five-year survival rate of only 13%,” says Dr. Darren Carpizo, a surgeon-scientist and member of the Wilmot Cancer Institute, who led the research. “I routinely see patients who undergo surgery and experience a recurrence despite our best efforts, and that is disappointing. Our new study brings us another step closer to understanding how these pancreas tumor cells can hide out for long periods of time, and how to target them.”

How Dec2 Helps Cancer Cells Evade the Immune System

When researchers disabled the Dec2 gene in laboratory experiments, the immune cells were able to locate and attack pancreatic cancer cells. This suggests that Dec2 could be a promising new target for future therapies.

Adding to the complexity, Dec2 operates on a circadian rhythm, fluctuating in activity throughout the day. Carpizo’s team discovered that the timing of immunotherapy administration could significantly impact its effectiveness. For example, treatments given in the morning appeared to be more successful than those given in the evening.

“This is a highly novel finding,” Carpizo says. “The circadian rhythm discovery provides a biological explanation for why some cancer immunotherapies are more effective if they are given to patients at certain times of the day.”

Implications for Pancreatic Cancer Vaccines and Immunotherapy

Recent headlines have featured an experimental mRNA vaccine for pancreatic cancer, tested in a small clinical trial at Memorial Sloan Kettering with 16 patients. The vaccine boosted survivorship for half of the participants, with eight patients remaining alive for several years after generating an immune response.

However, Carpizo notes that the other half of participants did not respond to the vaccine. “Vaccines like this one depend on T cells being able to seek out and destroy cancer cells,” he says. “Our research has important implications for this, because if the actions of Dec2 will not allow the vaccine to work.”

The findings underscore the need for therapies that can overcome the immune evasion tactics of pancreatic cancer, including strategies that target Dec2 or leverage circadian rhythms to optimize treatment timing.