Pancreatic cancer is typically a difficult cancer to treat, leading to poor outcomes and high mortality rates. One of the reasons for this is the difficulty of diagnosis; it often doesn’t come until the cancer has already progressed to the later stages. Metastasized cancer is much harder to treat. Modern chemotherapies and immunotherapies don’t typically have much of an effect. Because of this, medical professionals have to search for new strategies to treat pancreatic cancer.

Research recently published in Science Translational Medicine did just this. Medical professionals investigated a new immunotherapy strategy that utilizes tetanus vaccines and the immune system. You can read the full paper, titled “Listeria delivers tetanus toxoid protein to pancreatic tumors and induces cancer cell death in mice,” here.

About the New Immunotherapy

This new immunotherapy is very exciting, as it has demonstrated the ability to target hard-to-treat pancreatic tumors. To be specific, medical professionals utilized the tetanus vaccine to transfer immunity into cancer patients before triggering it with immunotherapy. With the use of the tetanus toxoid protein, researchers were able to make pancreatic cancer cells visible to the immune system, therefore allowing the body to attack them.

Let’s dive deeper into this.

The researchers working on this study knew that pancreatic cancer is notoriously difficult to treat as it is completely foreign to the immune system. They also knew that the majority of the population is vaccinated against tetanus, and this vaccine remains circulating in the bloodstream via tetanus-specific memory T-cells for a lifetime. Their strategy was to combine these two ideas to target pancreatic cancer.

To do so, the researchers utilized the Listeria monocytogenes bacteria to deliver a tetanus-associated toxin into pancreatic cancer cells. This bacteria is especially helpful as it is good at infecting and spreading through cells and tissue. This step was followed by an injection of tetanus-gene cargoes that activates the immune system – CD4 T cells specifically – to attack and kill pancreatic cancer cells.

When this strategy – followed by low doses of the chemotherapy drug gemcitabine – was applied to mice models of pancreatic cancer, tumors shrank by an average of 80%. Additionally, there was an 87% reduction in the number of metastases, and treated mice lived 40% longer than mice who were left untreated.

While future research is necessary, this is a very exciting start to a new treatment strategy for pancreatic cancer. This hard-to-treat cancer is in desperate need of new options, and the research may lead to one.

About Pancreatic Cancer

As the name suggests, pancreatic cancer impacts the pancreas, which is an enzyme-releasing organ in the lower stomach. These enzymes are needed for digestion, along with hormones that help with managing blood sugar. Medical professionals are unsure as to why tumors form in the pancreas, but they have identified a number of risk factors: obesity, a family history of pancreatic cancer, smoking, being male, and being over the age of 45. Regardless of cause, this cancer causes symptoms such as:

• Diabetes
• Unintended weight loss
• Pain in the upper abdomen that can spread to the back
• Jaundice (yellowing of the skin and eyes)
• Loss of appetite
• Fatigue
• Blood clots
• Dark urine
• Depression
• Bowel obstruction

Diagnosis often doesn’t come until later in disease progression, which makes this cancer difficult to treat. It often doesn’t respond to modern therapies. However, doctors use the following options: surgery, radiation therapy, chemotherapy, and targeted therapy. Supportive care is often a large part of treatment.