Can Chemotherapy BOOST the Immune System?!
Dr. Richard Frank—
I know what you are thinking. “There is an error in the title of this blog post! Chemotherapy destroys the immune system! How could it boost the immune system? What is this guy thinking?” Well, let’s take a look at things from another angle.
As an oncologist for nearly twenty years, I have cared for a great many patients with cancer. I have always been amazed at how certain individuals diagnosed with an incurable cancer live years beyond their expected prognoses whereas others succumb much sooner. Researchers have been unable to explain why this is so but for cancers such as pancreatic cancer, no clearly identifiable factor of either the cancer or the patient can predict who will do well with treatment and who will derive little benefit. One important area of cancer control that is difficult to measure is a patient’s immune response to their cancer. Could it be that differences in the immune systems amongst individuals determines survival or that cancer treatments such as chemotherapy can actually boost the immune system in certain situations? I went searching the medical literature for some answers.
Let’s use the example of pancreatic cancer. The most commonly utilized chemotherapy drug to treat pancreatic cancer is called gemcitabine (Gemzar is the trade name). Most of my long term pancreatic cancer survivors have been on gemzar for years. So, I wondered if this chemotherapy or any chemotherapy drug can actually boost a patient’s immune system to help fight their cancer. In fact, there are scientific reports of gemcitabine stimulating the production of immune cells called dendritic cells in the patients given the chemotherapy. Dendritic cells provide the bridge of recognition between the target of the immune system (such as cancer cells) and the T-cells that attack the target. Also, research testing novel ways of harnessing the immune system to recognize cancer have found that chemotherapy actually helps in this immune recognition.
All of this may seem out of left field because we are bombarded by the slogan, “chemo destroys the immune system.” As I explain in my book, certain chemotherapy drugs can reduce the numbers of infection fighting cells called neutrophils, leading to fever and infection. Fortunately, growth factors such as neupogen can speed the recovery of neutrophils after strong chemotherapy. But for other types of chemotherapies that are not so strong, such as gemcitabine, perhaps in some situations, in some patients, the chemotherapy is doing way more good than anyone suspects (except for a few researchers from Japan). Perhaps chemotherapy is killing cancer cells and boosting the immune system to fight the cancer all at the same time. Now that is food for thought and worthy of further study!
Richard C. Frank, M.D., is director of cancer research at the Whittingham Cancer Center of Norwalk Hospital, medical director of Mid-Fairfield Hospice, and Clinical Assistant Attending at Weill Cornell Medical College. He has been appointed cancer expert for WebMD and was named a “Top Doc” in the New York Metro area by Castle and Connelly.