“Immunotherapy has turned out to be a new and exciting way for us to treat cancer.”
When people think of cancer treatment, most people think of chemotherapy. While this treatment has been a staple of treating cancer for decades, it’s not the best treatment for all types of cancer. For example, for kidney cancer, chemotherapy is often not effective and is thus seldom used. Instead, one of the better options for treating certain types of kidney cancer is immunotherapy.
There are several types of immunotherapy, but in general, this treatment uses various medicines that boost the body’s own immune system to help it recognize and fight cancer cells. This is different than chemo, which targets any rapidly dividing cell, including cancer cells but also some normal and healthy cells. (Learn more about the difference between immunotherapy and chemotherapy here.)
The main type of kidney cancer that responds to immunotherapy is advanced renal cell carcinoma (RCC). This basically refers to cancer that starts in the cells that line the kidney, and in the advanced stage, the cancer has spread or metastasized to other parts of the body.
Checkpoint Inhibitors for Advanced RCC
To understand how immunotherapy works, you have to understand a little bit how the immune system works. “In general, our immune system works by recognizing itself as different than foreign objects, such as bacteria, viruses, or even cancer cells,” says Rujuta Saksena, MD, hematologist and oncologist in New Jersey.
One of the ways the immune system accomplishes this is by using a “checkpoint” system. Immune cells have proteins on their surface that can be turned on (to mark a cell as “safe” and keep the immune response in check) or off (to recognize a cell as a threat to attack). When working properly, this helps keep the immune system from attacking your normal, healthy cells.
Here’s the problem: “Oftentimes, cancer cells try and fog up our immune system’s ability to detect them, so that they are allowed to reproduce and grow,” says Dr. Saksena. They do this by activating those immune cell checkpoints, so the immune system doesn’t recognize the cancer cells as a threat.
Checkpoint inhibitors are a type of immunotherapy that block the cancer cells from binding to those proteins on the immune cell, which helps the immune cell recognize the cancer cell and attack it.
Think of it this way: When you enter an event, you might get a stamp on your hand or a wristband, which signals to event workers that you’ve paid your admission or are old enough to buy alcoholic beverages, for example. These stamps and wristbands are like checkpoints—you’re marked as safe to the event workers (the immune cells).
Checkpoint inhibitors work by making sure someone who shouldn’t have a stamp (a cancer cell) doesn’t have one, so that the event workers can quickly spot the intruder and kick ‘em out (the immune response).
There are two types of checkpoint inhibitors for advanced RCC:
PD-1 inhibitors, which target the PD-1 protein on immune cells to trigger an immune response
CTLA-4 inhibitors, which target the CTLA-4 protein on immune cells to trigger an immune response
Cytokines for Advanced RCC
Cytokines are another type of immunotherapy, but they are only used for a small portion of people with kidney cancer. Your body naturally contains cytokines, which are small proteins that help the immune system fight off threats. This treatment, however, uses manmade cytokines that help to boost the immune system against the cancer.
“Over the past decade immunotherapy has turned out to be a new and exciting way for us to treat cancer,” says Dr. Saksea. “Immunotherapy is very effective against some cancers, but not all, so the best way would be for the patient to have a conversation with his or her oncologist.”
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Immunotherapy for kidney cancer. Atlanta, GA: American Cancer Society, 2012. (Accessed on May 13, 2020 at https://www.cancer.org/cancer/kidney-cancer/treating/immunotherapy.html.)
Patient education: kidney cancer (the basics). Waltham, MA: UpToDate, 2020. (Accessed on May 12, 2020 at https://www.uptodate.com/contents/kidney-cancer-the-basics.)
What is kidney cancer? Atlanta, GA: American Cancer Society. (Accessed on May 12, 2020 at https://www.cancer.org/cancer/kidney-cancer/about/what-is-kidney-cancer.html.)