New cancer treatments focus on targeted therapies

SALT LAKE CITY — In the past, all cancers were treated with similar methods. Now, a Utah doctor says new targeted therapies are being used to treat cancer. 

Deputy Director of the Huntsman Cancer Institute, Dr. Theresa Werner says that is changing. Often, those treatments involved some sort of chemotherapy.

“These agents [chemotherapy] will go in and kill rapidly dividing cells. They tend to be relatively non-specific in the sense that they’re going to go in and try to eradicate any rapidly dividing cell. So, that’s great for the tumor cells, not so great for the normal cells in your body that are rapidly dividing,” said Dr. Werner. 

Dr. Werner explained that the agents also attack other cells. The list includes cells that line your mouth, your G.I. tract, and your hair follicles. 

“So there are certain chemotherapy agents that target those other rapidly dividing cells that we don’t want them to. And, we kind of refer to that as unfortunate collateral damage from the chemotherapy side effects.”

Dr. Werner said some treatments can now target a patient’s specific cancer.

“What research has done…is we [have] found that certain cancer cells have specific target proteins on the outside of them that make them especially responsive to a specific drug that targets that protein,” said Werner. “For example, a cancer makes too much of something. And this targeted therapy will go and stop up the too much protein that the tumor cells make.”

Targeted cancer therapy

Dr. Werner said this next wave of systemic targeted treatment is called target therapy.

“So this can be pills. This can be injections and this can be intravenous as well. But these medications have a specific target.”

According to Dr. Werner, providers often use a combination of therapies.

“So, we have a whole armamentarium of medications that we can use now to fight cancers.”

According to Dr. Werner, new therapies assess the mutations present in a cancer case. Instead of just starting someone on chemotherapy, doctors can use a treatment that specifically targets the cancer cells. 

“Every cancer type is different. So, we have certain targeted therapies for breast cancer, certain targeted therapies for prostate cancer, lung cancer. So a whole variety of medicines.”

As our understanding of cancers changes, Dr. Werner said that the way cancer is being treated is also evolving. 

“Now, we know lung cancer [for example] is multiple different diseases. And by studying the lung cancers, we have found certain markers that will help you; one: prognosticate, so tell you how well someone will do; and number two: help direct the therapy.”

According to Dr. Werner, nearly all cancers are made up of multiple diseases. She said that by analyzing each patient’s specific cancer, they can now target that cancer with precision medicines, for a customized treatment plan. 

“So, what we’re doing now, which we weren’t doing routinely, you know, even a decade ago, we’re sequencing people’s tumors. So, there’s something called a tumor profile.”

Targeted therapies

According to Dr. Werner, doctors can use a patient’s tumor that’s been removed or biopsied or a blood sample and analyze it for mutations.

“We get a report of all those mutations… we can look at those mutations and go back and figure out which medicines are best targeted to that patient.”

Those treatment plans then use a combination of three methods to treat those cancers, said Dr. Werner.

The difference in these new treatments is that unlike system-wide chemotherapy, which kills all rapidly dividing cells, these new systemic treatments target the cancer cells directly. 

In other words, the new treatments are more selective. 

“Medications sometimes are attached or they’re antibody driven for example, and they have the target on them that actually will seek out and find the tumor,” said Dr. Werner.

According to Dr. Werner, another of the other more recent therapies has “combined antibiotic therapies where we actually target the tumor with an antibody. And then attached to the antibody we have a little bit of chemotherapy. So, there are a lot of chemotherapy agents we can’t give to somebody at full dose because it’s too toxic. But if we apply a little bit to an antibody target, we can get it to go in and hone and find the cancer and then deliver a small amount of chemotherapy.”

Dr. Werner called it a “Trojan horse model.” 

How do they work?

She explained that the engineering of the antibody allows it to target and attach to cancer cells. 

“Then the antibody gets taken in by the cell and along with it [is a] little ball of chemotherapy and then it delivers the sort of toxic blow right to the cancer cells.”

Learning how to target specific cancers has another effect. Dr. Werner said it’s making it easier to find drugs to target and treat different cancers.

“So, every patient gets personalized medicine. The more current term is precision medicine. So being able to precisely identify these mutations in a person’s tumor and then precisely pick the right therapy for said patient.”

Additionally, Dr. Werner said immune therapy is another exciting idea. It uses each person’s immune system to fight cancer. 

“People always ask me, ‘Well, why doesn’t your immune system fight cancer anyway?’ And that’s a great question. So, your immune system cells are supposed to recognize anything that’s foreign. So for example, if you got an infection it revs up your immune system and helps fight the infection,” she said. 

According to Dr. Werner, cancer cells are tricky because they look too much like normal cells and therefore, evade the immune system.

“So, the immune system doesn’t get triggered by these cancer cells because they look normal even though they’re not normal. Immune therapy actually kind of takes the brakes off your immune system and lets your immune system actually find these cancer cells, [using] your body’s own immune system to fight the cancer.”

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