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The Misconception of "Preventative" Chemotherapy

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The Misconception of "Preventative" Chemotherapy

May 01, 2024

Can chemotherapy be used to prevent cancer? The short answer is no. Theresa Werner, MD, Deputy Director of the Huntsman Cancer Institute, debunks the notion of "preventative" chemotherapy in healthy individuals and explains the real preventive measures that can reduce cancer risk.

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    Interviewer: Today we're discussing an important yet often misunderstood aspect of cancer care. It's called preventive chemotherapy, and it's been in the news lately. But can chemotherapy really be used to prevent cancer?

    Joining us today is Dr. Theresa Werner, the Deputy Director of Huntsman Cancer Institute, and she's going to explain to us a little bit about how doctors work to prevent cancer and what chemotherapy is actually used for. Dr. Werner, let's start at the beginning. What exactly is preventive chemotherapy, and what has people misunderstanding what it is?

    Primary Prevention: Keeping Cancer at Bay

    Dr. Werner: I think a lot of people know some things about chemotherapy, and people know things about the prevention of cancer. But the term "preventative chemotherapy" together is a little bit confusing. Firstly, the prevention of cancer is really divided into primary and secondary prevention.

    So when we think about primary prevention of cancer, it's a set of interventions that keeps the cancerous process from ever developing in the first place. And that would include things like health counseling and education, controlling your environment, and avoiding bad things for example.

    Interviewer: Like smoking.

    Lifestyle Choices: Weight, Tobacco, Alcohol, and Sun Protection

    Dr. Werner: Yeah, exactly. So I'll give you some perfect examples. So you can reduce your risk of even getting cancer in the first place by making healthy choices, and that would include keeping a healthy weight. So that ties into a healthy diet, regular exercise, and avoiding tobacco, of course. So tobacco use is the leading cause of cancer and cancer deaths. And about 3 in 10 cancer deaths are caused by cigarette smoking. Lung cancer is the leading cause of cancer death in both men and women. So avoiding tobacco use, and that would include vaping as well, so really important for the younger generation who they're like, "We're not smoking cigarettes." But they're vaping. And so we would worry about that as well, right?

    So healthy weight, avoiding tobacco, limiting the amount of alcohol that you drink, and protecting your skin. Something as simple as sunscreen and covering up when you're out in the sun, and that's especially important in Utah because, number one, we're at a very high altitude, and number two, we love our outdoor sports in Utah, including skiing and being outside. So really important to protect your skin.


    Other examples of primary prevention would include the HPV vaccine, for example, so getting the HPV vaccine, which is available to both young women and men, including adolescents. We know that HPV is the main cause of cervical cancer. So if you actually get the HPV vaccine series, you can prevent cervical cancer from even developing in the first place. So a great example.

    Medications for High-Risk Individuals

    There are a few medications that people can take to prevent cancer. I will give you an example. So not chemotherapy. Chemotherapy, when we think about chemotherapy, these are medication that people take either by mouth or intravenously in a vein. Sometimes they're injections. Those meds go in and kill any rapidly dividing cells. So a rapidly dividing cell would be a cancer cell for example.

    So prevention medications, there's a very common medication called tamoxifen, which a lot of people have heard of because we use it in the treatment of breast cancer. But in high-risk families, for example, who have a high risk of developing breast cancer, there are certain patients where we would use tamoxifen, which is basically an oral antiestrogen type therapy, to prevent breast cancer from developing in the first place. So that's an example of a preventative medication, but that's not chemotherapy.

    Secondary Prevention: Early Detection Saves Lives

    And so if I switch to secondary prevention of cancer, secondary prevention is what a lot of people think of when they think of cancer screening. So it's a set of interventions leading to the discovery and control of any cancerous or even precancerous conditions while that precancer or cancer is localized, right? So if you find cancer when it's small and when it's early, you have a higher chance of removing it and potentially curing the patient. So that would be secondary prevention of cancer.

    Cancer Screening: Mammograms, Colonoscopies, Pap Smears, PSA Tests

    So that's what a lot of people know as cancer screening. So a perfect example is mammograms, getting your regular mammograms to detect breast cancer early. Another example would be a colonoscopy, right? So we do colonoscopies and they've dropped the age to 45. It used to be 50. So screening colonoscopies is happening at age 45 now. And really what colonoscopies are doing is they're looking to detect any early colon cancers, but also they're looking for colon polyps because polyps can turn into colon cancer. So in a way, you could even do primary prevention if you can remove a polyp, right, so it doesn't turn into colon cancer.

    And then, of course, there is getting your regular pelvic exam and doing a Pap smear to look for cervix cancer as a way to detect cervix cancer early. And then getting your PSA, your prostate-specific antigen checked as well for our male patients who have prostates for example.

    So really we're looking at whether can you prevent cancer from happening in the first place. And then the secondary prevention is, can you detect it early? Can you do screenings so that you can effectively cure the cancer?

    Clarifying Preventive Chemotherapy

    So now if we get back to your original question, Mitch, about preventative chemotherapy, we use chemotherapy in the oncology world to treat all kinds of cancers. So the case that has been in the news lately, there was a surgery and cancer was discovered and effectively removed it seems like. And so then people are asking, "Why does someone need chemotherapy if the cancer has been removed?" And that's probably the number one question we get from our patients after they've had an effective surgery, and then they come to see a medical oncologist, like myself, and we talk to them about chemotherapy. And that's the first question, "Why do I need chemotherapy?"

    Adjuvant Chemotherapy: Reducing the Risk of Recurrence

    It all comes down to the risk of cancer recurrence, right? So if there was a big cancer, an aggressive cancer, let's say, for example, the cancer was in lymph nodes, there's a higher chance that that cancer will come back, right? And so we refer to doing any additional therapy at that point adjuvant therapy, so after surgery. And that can include chemotherapy, and that can include radiation therapy for example. And so I think in the case that's been in the news, there was a high-risk cancer that was removed, and they're doing chemotherapy in an adjuvant setting, so giving the patient chemotherapy in case there's any microscopic disease left behind. It must have been a high-risk case.

    Role of Chemotherapy in Cancer Treatment

    And so the point of chemotherapy is to eradicate any microscopic residual cells to prevent recurrence. So it's not really preventing the cancer because she already had cancer. It's actually trying to prevent a recurrence. So I think that's where the terminology is different. So they're not preventing the cancer in the first place. They're preventing a recurrence, and that's why she's getting chemotherapy I think.

    Interviewer: So again, just to kind of summarize, no, you can't go into a doctor's office and get loaded with chemotherapy to stop or prevent cancer, correct?

    Limits of Preventive Chemotherapy

    Dr. Werner: Absolutely. So if you go back to what I said earlier, right, these chemotherapy medications, they go in and they kill rapidly dividing cells. So if the cancer is a precancerous lesion or it's eventually going to turn into cancer, it's not a rapidly dividing cell. So giving somebody chemotherapy, in that sense, to truly prevent cancer from happening in the first place is actually just going to cause side effects because while cancer is a rapidly dividing cell, there are other rapidly dividing cells in your body that are normal. So the cells that line your mouth, so some patients who get chemotherapy get mouth sores for example. Your hair follicles are rapidly turning over, so that's why patients lose their hair, right? So it's all the collateral damage to the normal body that we see with chemotherapy.

    So when we're talking about chemotherapy, there's a risk-benefit ratio, right? So in cases where we can prevent a recurrence, that's why we would do chemotherapy. But to give a healthy person, who might have a chance of cancer, chemotherapy would not be done, and that would cause a lot of side effects. Yeah.

    Interviewer: Got you. So the main ways that we can prevent cancer, both primary and secondary, we can make sure we're not doing things to have cancer form in the first place, and we can do our screenings to make sure, hey, we can catch it early enough that it doesn't turn into something more severe.

    Dr. Werner: Absolutely.

    Resources and Guidance

    Interviewer: Say there's someone listening right now, they were curious. They got here because they were curious about how they could prevent cancer. Are there any resources, or what steps should they be taking to find out more about these primary and secondary prevention methods?

    Dr. Werner: Yeah, that's a great question. So I would recommend that for most patients who have questions, this is usually covered at their primary care doctor's appointment. So whether it's a child and they see their pediatrician and they're going to get their immunizations, for example, we talked about HPV vaccine, or it's an adult, they would see their family medicine doctor or their internal medicine doctor for example. A lot of young to middle-aged women are still seeing their OB/GYN, who's doing their Pap smear checks and things like that as well. So any of your primary care providers in that sense should be talking to every patient about screening and making sure.

    So even in my patients, and I specialize in gynecologic cancer, I still touch base with them about other screening because they're here at the doctor, so every opportunity a patient has when they see the physician, we use it as an opportunity to talk to them about screening. So I will harass them about getting their colonoscopy and getting their mammogram.

    And so doing secondary prevention with cancer screening is important, even in patients who have already had cancer, right? So you still need to screen for the other cancers as well. So the first thing I would do is talk to your physician. There are a lot of good internet resources as well. So if they look at the Huntsman Cancer Institute website, we have a page dedicated to cancer screenings. We actually have a lot of research being done about the prevention of cancer here at the Huntsman Cancer Institute, including sun safety, and tobacco cessation, for example. So a lot of great work is being done here, and healthy patients can participate in that research as well. And then I would say the American Cancer Society is a reliable website that people can go to if they have questions.

    And again, they can always call Huntsman Cancer Institute if they have questions. 801-587-7000 is our number. So they can always call as well.