Vaccine Therapy

Please scroll to the bottom of this page for definitions of all bold faced words.

** Please note, cancer vaccines are currently available only by participation in a clinical trial.  Cancer vaccines are not used to prevent cancer occurrence. **

While traditional vaccines, such as those given during childhood, aim to prevent infectious diseases, most cancer vaccines currently focus on treatment for those already diagnosed with the disease.  The goal of cancer vaccines is to help the body recognize cancer cells and to stimulate the immune system to respond.

How do cancer vaccines work?

All cells have unique molecules on their surface. When operating properly, the immune system recognizes the difference between molecules on normal healthy cells and those on foreign cells, called antigens. The presence of antigens usually stimulates the immune system to attack the foreign cells. In the case of cancer cells, the molecules on their surface sometimes differ so slightly that cancer cells go unnoticed by the immune system. In addition, cancer cells sometimes develop mechanisms that suppress immune recognition so that no immune response occurs, and the cancer cells can grow and multiply out of control.

The goal of cancer vaccines is to awaken the immune system to distinguish antigens on tumor cells and destroy them. There are many different types of pancreatic cancer vaccines being developed by researchers to produce a cancer-specific immune response, including the following:

•  Antigen vaccines stimulate an immune response to a specific antigen unique to a specific tumor.

•  Whole cell tumor vaccines use whole pancreatic cancer cells from a specific patient's cells or from lab-grown cells to make a vaccine.

•  Dendritic cell vaccines use specialized cells, called dendritic cells, that activate the immune system. These cells are derived from the patient's blood, are modified and multiplied in the lab, and are reintroduced to the patient.

•  Idiotype vaccines are composed of antibody molecules unique to each patient that can trigger an immune response.

When are cancer vaccines used?

Vaccines for pancreatic cancer are still in the experimental phase.  Currently the only way to obtain a vaccine for pancreatic cancer is to participate in a clinical trial.  Each clinical trial has its own requirements for participation and all require that participants currently have pancreatic cancer.  In these clinical trials, pancreatic cancer vaccines are used as part of a patient's treatment and are rarely used alone.

An important application of a cancer vaccine may be to eliminate microscopic cancer cells that might remain after surgery, therefore preventing the cancer from recurring.  Another application may be to prevent further growth in patients who are not candidates for pancreas surgery.

What are the benefits and side effects of pancreatic cancer vaccines?

As with other pancreatic cancer treatments, there are benefits and side effects. Cancer vaccines are beneficial because they:

•  use the body's own immune defense mechanisms.

•  provide an alternative to or enhance the efficacy of standard chemotherapy.

•  produce minimal side effects.

Side effects of cancer vaccines:

•  are generally milder than chemotherapy and tend to be associated with cold or flu-like symptoms (fever, headache, nausea, fatigue, etc.).

•  may occur around the injection site, such as redness, itching and/or sores.

•  may cause improper immune response. The immune system could potentially attack normal cells as well as cancerous cells. This reaction could include signs of an inflammatory response, such as fever and muscle and joint aches. If the reaction is against the pancreas itself, this could lead to pancreatitis .

Research and development efforts are underway to thoroughly evaluate the safety and efficacy of different approaches to pancreatic cancer vaccines. To receive more detailed information about pancreatic cancer vaccines or related clinical trials contact a PanCAN PALS Associate at 877-272-6226 or pals@pancan.org.

GLOSSARY

Antigen: Substance that causes the immune system to make a specific immune response.

Antibody:   A protein made of certain white blood cells in response to an antigen. Each antibody can bind only to a specific antigen. The purpose of this binding is to help destroy the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to come and destroy the antigen.

Clinical Trial: A research study that involves human participants and is designed to answer scientific questions about treating and preventing cancer.

Dendritic Cells: A special type of antigen-presenting cell that activates immune system cells, called T lymphocytes, to attack.

Immune System: The complex group of organs and cells that defends the body against infection or disease.

Pancreatitis: Inflammation of the pancreas. Pain is the primary symptom.