In the ongoing fight against cancer, immunotherapy has emerged as a promising alternative to surgery and chemotherapy, utilizing the patient’s immune system to provide effective cancer treatment without burdensome side effects.
“It’s been a huge gamechanger in oncology, and it’s definitely what everyone wants to study,” says Dr. Kevin Koehler, a medical oncologist at Sarasota Memorial. By his estimation, there are 50 active clinical trials involving immunotherapy, just in our region, compared to zero for chemotherapy.
But how does immunotherapy work?
Flipping A Switch
The most common type of immunotherapy used by oncologists with Sarasota Memorial’s Brian D. Jellison Cancer Institute involves the use of “checkpoint inhibitors,” antibodies made in a lab and designed to help the body’s immune system target the cancer.
“In general,” says Koehler, “cancer has a way of turning the immune system off so it can avoid being destroyed by T cells.”
T cells are crucial to the functioning of the immune system, responsible not only for detecting and eliminating harmful pathogens and foreign bodies but also rallying other cells to join the fight. Avoiding detection by T cells is what allows cancer’s uncontrolled growth and spread — and what makes cancer so dangerous.
“But checkpoint inhibitors turn that signal back on,” explains Koehler. This allows T cells to recognize cancerous growths as harmful and to start rallying the body to destroy the cancer on its own.
It’s no secret that many cancer treatments can be nearly as rough on the patient as the disease itself. Radiation therapy and chemotherapy, as targeted and precise as they have become, still have the potential for serious side effects. Surgery brings its own risks.
With immunotherapy, doctors are seeing minimal side effects and minimal disruption of daily life.
An outpatient procedure, immunotherapy infusions are given to patients once every 2 to 3 weeks, and the whole process takes about an hour. With no treatment-related nausea concerns, patients have no eating restrictions.
“People feel pretty good when they’re on immunotherapy,” says Koelher. “It’s not like chemotherapy.”
And even when immunotherapy doesn’t destroy a patient’s cancer completely, it can empower the immune system to hold the disease in check. Even patients with metastatic lung cancer have been able to live for years after receiving immunotherapy.
The End of Chemotherapy?
“I probably do as much, if not more, immunotherapy as I do chemotherapy,” says Koehler, and that’s the direction he thinks the field is headed. Still, immunotherapy remains markedly limited in its application and cannot be used to treat every type of cancer.
Cancer comes in all shapes and sizes, Koehler explains, and that means immunotherapies need to as well.
Immunotherapy is not a catch-all cure or panacea for every type of cancer, but a targeted body of therapies designed to treat specific cancers. Thus, a checkpoint inhibitor that works wonders to fight some Stage IV lung cancers may have no beneficial impact on pancreatic cancers, renal cancers or even other lung cancers.
But doctors do have tests they can run to see if immunotherapy will be effective against a patient’s cancer.
“What we’re looking for across tumor sites are what are called ‘predictive biomarkers,’ ” says Koehler. Predictive biomarkers are formations on the surface of the cell that are particular to cancers and differentiate them from non-cancerous cells.
And if a test reveals a high number of a specific biomarker, oncologists can surmise a favorable reaction to immunotherapy.
“That’s the Holy Grail of oncology,” Koelher says. But for most cancers, chemotherapy and surgical oncology remain the more common, standard treatments.
As the technology behind immunotherapy creation evolves, scientists explore the possibility creating custom T cells designed to hunt and destroy specific cancer cells. They’re called “Chimeric Antigen Receptor T cells,” or CAR-T cells.
“Instead of just nonspecifically turning that T cell on, like we do with checkpoint inhibitors,” says Koehler, “we actually take a patient’s T cells and genetically program them to target something in their body.”
These CAR-T cells have already found great success in treating certain lymphomas. “It seems to work like nothing’s ever worked in the past,” says Koehler — but the science remains in the early stages, and the therapy is not yet available for widespread use.
Still, Koehler sees the road presented by immunotherapy as a promising one for the future of his field.
“As we start to understand the biology of cancer better, of individual cancers, we can design treatments that are better tailored to them.”
For more information on immunotherapy or the Jellison Cancer Institute, contact Sarasota Memorial’s Cancer Information Office at 941-917-1981.
As a Sarasota Memorial copywriter and wordsmith, Philip Lederer crafts a variety of external communications for the healthcare system. He earned his master’s degree in public administration and political philosophy from Morehead State University, Ky