Drug Treatments & Radiation Therapy for Pancreatic Cancer
Aside from surgery, other treatment options include chemotherapy, immunotherapy and newer types of radiation. There are also many ongoing clinical trials involving immunotherapy and targeted therapy.
Chemotherapy is the use of drugs to kill cancer cells. It is a systemic treatment, which means the drug enters the bloodstream and travels throughout the body to reach the tumor cells. It may be given orally or by injection, or may be delivered through a catheter in a vein. Chemotherapy may be used alone or combined with either radiation therapy or surgery.
Types of Chemotherapies
The choice of which treatment to use depends on your health and the location and size of the tumor. Additionally, certain characteristics of the tumor may make it suitable for treatment with specific drugs. Therapy is usually given as a combination of drugs that have been tested and validated in clinical trials. It may be beneficial to have blood and tissue from your tumor tested for inherited mutations, which may present targeted treatments as additional options.
Chemotherapies for patients with nonresectable tumors commonly include gemcitabine with nab-Paclitaxel (Abraxane) or FOLFIRINOX, which is the combination of four chemotherapies in one (5-fluorouracil, leucovorin, irinotecan and oxaliplatin). Additional strategies include fewer drugs or the addition of cisplatin.
Chemotherapy may not kill all cancer cells. Tumors are often surrounded by a stroma, which is made up of normal cells called fibroblasts, as well as immune cells and a sticky substance called the extracellular matrix. The stroma around the tumor seems to protect it from chemotherapy, however, it may also prevent the cancer from metastasizing.
Another treatment approach is to target the changes in cancer cells that help them grow, divide and spread. There are many targeted therapies and monoclonal antibodies currently being investigated in clinical trials to determine if they can benefit patients with pancreatic cancer. Most targeted therapies are either small-molecule drugs or monoclonal antibodies.
Small-molecule drugs are small and can easily enter cells. These drugs have targets that are inside the cells.
Monoclonal antibodies are large molecules that attach to specific targets on the outside of cancer cells. Monoclonal antibodies may have a direct effect on cancer cells, but they can also mark cancer cells so that a patient’s immune system destroys the cancer cells.
The immune system protects against infections and usually gets rid of mutated cells in the body. However, cancer cells are able to hide from the immune system, preventing the immune system from destroying them. Immunotherapies are types of biological therapies that use substances to stimulate the immune system to help the body fight cancer, infection and other diseases. Currently, the only immunotherapy approved for pancreatic cancer is pembrolizumab (Keytruda®). This treatment has proven effective for advanced pancreatic cancer patients whose tumors are mismatch repair deficient (approximately 1%-2% of patients). The study leading to its approval was funded by the Lustgarten Foundation.
Radiation therapy (also called radiotherapy) uses high-energy X-rays to shrink tumors by killing cancer cells. External beam radiation therapy is the type most commonly used to treat pancreatic cancer. A beam of radiation from outside of the body is focused on the tumor, similarly to what is done during a diagnostic X-ray, only at much higher doses of radiation.
Radiation is often given at the same time as chemotherapy, but may be given by itself before or after completing chemotherapy. Learn more about radiation therapy here.