Heartland Oncology & Hematology

House Calls with Dr. Robert Warner

Sunday Mornings at 9:30am on KMA 960 AM

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Sep 28, 2008

Cancer Treatments and Vaccines


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My name is Patrick Hawks. I'm interviewing Dr. Robert Warner of Heartland Oncology and Hematology.
So tell me, there are three categories of treatments of cancer, is that correct?

I think that's a fair statement. We can break the treatments down into three ways you can treat the cancer.
You can cut it out - Surgically.
You can use radiation therapy - Now there are several different types of radiation therapy, but basically radiation kill cells by alkilating them, and they all act the same in that regard.
Or you can use, I would like to use the term Systemic therapy. Classically, we lump that in and call it chemotherapy, but systemic just means whole body.
You've got the classic sydotoxic drugs that get in there and kill, and they pretty much kill nondiscriminatly. The first sydotoxic drug we had was nitrogen mustard and the story goes, this is almost too good to be true so I'm not sure if this is made up, but during the war, a couple of people with either lymphoma or Hodgkin's disease, probably Hodgkin's disease but I'm not sure, were exposed to nitrogen mustard - nerve gas - and their cancer got better. Someone was bright enough to say "Hey, this stuff really works."
We still use that type of drug, too. We don't use a lot of nitrogen mustard anymore, a little bit, but not too too much.
So that's the classic sydotoxic agents.
Then we have hormones. A few tumors are hormonally dependent, classically breast cancer and prostate cancer. And hormones are systemic treatment also. You can call those chemotherapy if you wish, they're systemic.
Then we have a new group of agents that are called monochlomal antibodies, that's targeted therapy. Again, it's systemic, it goes in the wholes body, but unlike the classic sydotoxic agents like nitrogen mustard which kill nondiscriminatly, these will bind to a specific antigen, ideally just on tumor cells. The first one we had was a drug called Rutoxin, which bound with a protein named CD-20 - they've all got bad names - and then it will kill the cell that is attached to that protein.
All of these make up systemic therapy, which we generically call chemotherapy. Systemic because it will go virtually throughout the whole body. I would like to point out that we have a blood/brain barrier, and there's a lot of scientific debate about how tight the blood/brain barrier actually is, but very few drugs are effective in the brain, but anywhere else the drugs can go to.
About the differences in the treatment modalities.
If something is local, you can completely cut it out. If you're really sure something is local, it's hard to beat that.
Radiation, also, is very good at where it's aimed. In most cancers of course, some cancers are less radio sensitive than others. If a cancer is in several different areas, you can't cut it out and you can't radiate the whole body, then the systemic therapy is usually the way to go.
And of course the best treatment would be prevention, correct?
Absolutely.
As good as our treatments are, honestly if we got everybody to quit smoking, that would probably do more good than everything else we've done. I realize that's not going to happen, but truly prevention, certainly smoking being the most logical one.
You know, I kind of hate to even harp on that too much because I assume everybody know that - maybe I'm wrong and should harp on it more - but I assume everybody knows and we're all adults and I'm not so sure that forcing people to do what they don't want is such a good idea, but none the less, smoking is associated with lots of malignancies.
Other prevention, too - Dr. Dolizal was on last week and talked a lot about sun exposure. Certainly for skin cancers that's a major risk factor. For colon cancer, high fiber diets will decrease the risk. For breast cancer, high fat diets will increase the risk.
The best treatment is prevention.
How about vaccines? I've been hearing a little bit lately about a cancer vaccine for ovarian cancer. What can you tell me about that?
The vaccines have been on the horizon for quite a while. The idea there being, you could think of it as being somewhat analogous to the treatments where we have a monochlomal antibody where we can inject an agent that will bind with a specific antibody, so just the cancer cells.
Well, how about if we can get the body to do that?
If you think about it, vaccinations that we've had for the last hundred years or longer... What Pastera did back in the 19th century with the original vaccinations is, he would inject a small amount of a toxin - say smallpox or maybe cowpox - into the person, they get sick and they build up this big antibody response to it, so then when they're exposed to the real thing, they're immune to it. They've seen it one before, they've got A immune response.
As anybody with allergies can tell you, the first time you were exposed, if you think about it, the first time you were exposed, you weren't allergic. You didn't have any antibodies built up; you're immune system wasn't aware of it.
The second time, now you've already been exposed and the response tends to get worse.
It's the same idea here, Patrick. The idea being that we can build our immune systems to be resistant to certain types of cancer.
I think it's the next big thing. It's been on the horizon for years, but to be practical, it's got to be something that's generalizable enough. What we have found with tumor vaccines so far is that, if we have somebody with a cancer, we can take their cancer and make vaccines specific to that cancer. That's extraordinarily expensive, plus it's a little later than we'd like to be.
But the vaccination concept is very good, and I do think it will come around, at least for certain cancers, maybe not for all.