An evolving science
Advances in immunotherapy have had a continual impact on how physicians help patients with cancer, bringing a complex mix of challenges and successes, says Barbara Galligan, M.D., an oncologist at Marin Cancer Center.
“Immunotherapy means a lot of different things,” she says. For example, the Food and Drug Administration (FDA) has approved immunotherapy for use on only some cancers, including metastatic melanoma, lung cancers, bladder cancer and others. “These are new, expensive, drugs that are promoted with direct-to-consumer advertising campaigns resulting in patients coming in to their doctors asking for immunotherapy.”
“Immunotherapy doesn’t work on every cancer, says Galligan. “Or, it may not be the right time for immunotherapy. There are times over the course of someone’s treatment where immunotherapy may or may not be useful.” She explains some of the complex conditions behind the miraculous-appearing results portrayed on ads.
“The thing about immunotherapy is that if you have a great response, it looks like a true miracle drug,” says Galligan. For example, there are people whose cancers such as a deadly metastasized melanoma, have disappeared for years after treatment with immunotherapy. “But the flip side is that there are patients who won’t respond,” she adds. Current statistics place the responders (those who show lasting improvement) in the neighborhood of 20 to 30 percent. This means there are a great many for whom the drug, no matter how seemingly miraculous for others, does not work.
Why don't all patients respond? “We’re learning that cancer is not just one disease,” says Galligan. “It’s many diseases. And even within one cancer type (lung cancer, for example), there are many different types.” According to Galligan, it’s important to take a sample of a patient’s tumor to take a closer look at the biology. “If you take a sample and study it, you can see the differences,” she says. “The closer you look at the biology, [you note] there’s a lot of variability.” One patient’s lung cancer may not be the same as another patient’s lung cancer. “That’s what predicts [a patient’s] response to immunotherapy.”
Another complication is that the cancer’s “disguise” can be outsmarted by the immunotherapy drug, but the cancer may mutate and outsmart it back. As a result, says Galligan, you may need to change treatment to select for new mutants that are not going to go away with prior treatments.
Currently, medical science is working to find ways to predict whether cancer patients will respond to immunotherapy. “That’s a nascent field and I hope it gets better every year,” says Galligan. Some patients are set on immunotherapy, and are frustrated when they hear that it might not be the right treatment for them at the time, she adds. When preparing for treatment, she says, the best approach is to find a doctor who will support you. “It’s important to find an open-minded, enthusiastic oncologist and to establish a good doctor-patient relationship, one with communication and trust, because the field is complex, and [immunotherapy] is not one-size-fits all,” she says.
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