A healthy immune system usually does a good job of identifying and destroying pathogens that invade the human body and cause illness. However, when it comes to cancer, the immune system sometimes falls short.
Using a variety of cunning mechanisms, cancer cells are often able to evade the immune system or impede its effectiveness, giving cancer free rein to grow and spread. As Rex Mowat, MD, of The Toledo Clinic Cancer Centers puts it, “Mutated cells that become cancer are like a wolf in sheep’s clothing. The immune system doesn’t recognize the wolf because all it sees is a sheep.”
The good news is, with the advent of cancer immunotherapy, oncologists now have a powerful tool in their arsenal that helps “unmask” cancer cells and revs up the immune system so it can go on the offensive against cancer cells.
“Immunotherapy drugs don’t attack cancer directly,” Dr. Mowat explains. “Rather, they augment or ramp up the immune system so it recognizes and attacks cancer. Several different drug classes are used for this purpose. They all work slightly differently, but all of them are a manifestation of the same idea.”
In contrast, chemotherapy drugs destroy or manipulate the DNA in cancer cells, killing them or preventing them from replicating. Though often effective, chemotherapy can also destroy healthy cells, causing side effects. According to Dr. Mowat, “With chemotherapy, there’s a small window between killing cancer cells and harming the patient.”
Immunotherapy can lead to side effects as well—examples include autoimmune rash, hepatitis, colitis, pneumonitis, and retinopathy—but they’re not related directly to the drug or when it was administered. “Patients who receive immunotherapy can go without problems for months and then suddenly find that their ramped-up immune system is attacking one of their organs. Occasionally the side effects are very serious, but in most cases, they’re mild and easily controlled,” Dr. Mowat states.
One example of immunotherapy in wide use is a class of drugs called checkpoint inhibitors. These drugs work by blocking proteins called immune checkpoints, which the body produces naturally to prevent the immune system from attacking healthy cells. Certain cancers exploit the process by producing immune checkpoints of their own. Checkpoint inhibitors essentially strip away this “camouflage,” allowing the immune system to identify and attack the cancer.
Other examples of immunotherapy include the use of monoclonal antibodies that attach to specific proteins on cancer cells and flag them for destruction, the use of genetically modified viruses that trigger the immune system to attack cancer cells, and the use of vaccines to train the immune system to recognize and attack antigens specific to certain cancers. Dr. Mowat notes that immunotherapy by itself has proven to be very effective in fighting certain cancers, such as melanoma and renal cell cancers. “In fact, right out of the box, immunotherapy hit a home run against melanoma. It appears to be curative for about a third of melanoma patients, which is something we never saw before when the only treatment option we had was chemo,” he comments.
Immunotherapy can also be combined with other therapies to achieve better outcomes than would be possible with either treatment alone. “For instance, we see improved survival rates in patients with triple-negative breast cancer when they’re given both chemo and immunotherapy before and after surgery. There are numerous combinations we can use depending on the type and stage of cancer,” Dr. Mowat states.
The Toledo Clinic Cancer Centers, located at 1200 Medical Center Parkway in Maumee and 4126 N. Holland Sylvania Road, Suite 105 in Toledo, also provides imaging, laboratory, chemotherapy, specialized pharmacy, and IV services. The cancer center consists of 13 physicians and 11 advanced practice providers. The cancer center also has satellite centers in Napoleon, Bowling Green, Wauseon, Bellevue, and Monroe.
The Toledo Clinic Cancer Centers has earned Patient-Centered Specialty Practice recognition and Oncology Medical Home recognition from the National Committee for Quality Assurance. Oncology homes align systems and resources with coordinated care focused on cancer patients and their needs. This reduces fragmentation, supports shared decision making, and improves the patient experience. They are the first oncology practice in the state of Michigan and the second oncology practice in the state of Ohio to receive this recognition.
For more information, please call The Toledo Clinic Cancer Centers at 419-479-5605. ✲
