Oral Side Effects of Breast Cancer Treatment

Welcome to The Breastcancer.org Podcast, the podcast that brings you the latest information on breast cancer research, treatments, side effects, and survivorship issues through expert interviews, as well as personal stories from people affected by breast cancer. Here’s your host, Breastcancer.org senior editor Jamie DePolo.

Jamie DePolo: Thanks for listening. A number of breast cancer treatments, including chemotherapy and some targeted therapy medicines, like Herceptin, can cause oral side effects, including mouth sores, dry mouth, and oral infections.

To help us understand these side effects and how they’re treated, our guest is Dr. Thomas Sollecito, chairperson of the Department of Oral Medicine at the University of Pennsylvania’s School of Dental Medicine, where he is also associate dean of hospital and extramural affairs. He also serves as chief of the Oral Medicine Division for Penn Medicine. Dr. Sollecito, welcome to the podcast.

Dr. Thomas Sollecito: Oh, you’re welcome. Thanks so much for having me.

Jamie DePolo: I’m very grateful to you for doing this because I think oral side effects are something that people don’t necessarily think of right away when they think about breast cancer treatment or cancer treatment in general, so I’m very happy to talk about this.

My understanding is that mouth sores, dry mouths, and oral infections or abscesses are some of the most common oral side effects that happen because of breast cancer treatment.

So, for simplicity’s sake, I’d like to go through them one at a time, and we can sort of talk about them. So, the first one is mouth sores, which I know are very painful. I have not had them from chemotherapy, but I’ve had them from other things. So, in your experience, which breast cancer treatments are most likely to cause these, and why do they cause them, and then how are they treated?

Dr. Thomas Sollecito: Sure. So, really, in order to best explain the answer to this question, we need to understand just a few things about the breast cancer treatments, and no, I’m not an oncologist, but we still need to understand the breast cancer treatments, beyond surgery and radiation, and that these treatments really are just continuing to evolve. But the types of medications that folks will use for breast cancer treatment are based on really the type of breast cancer, the grade, the stage of the cancer, the molecular subtype of the cancer, whether it has certain types of markers.

And it’s really based upon these aspects that different medication regimes are chosen by the oncologists. But very broadly speaking, there are medications, chemotherapeutic medications, or medications that are used to treat breast cancer that will decrease blood counts. Most specifically, the white blood cell count and the red blood cell count. And this is really more of the traditional chemotherapeutic agents that are used, and it’s these chemotherapies that often can, and do cause, mouth sores.

It sort of gets compounded because if the white blood cell counts are low, the patient becomes more susceptible to different kinds of infections, like yeast infections and viral infections in the mouth. And these, of themselves, can cause different types of mouth sores. So, the chemotherapy itself, as well as the infections that may ensue, because your blood counts are low, can cause mouth sores. And that’s the more traditional chemotherapies that are used to treat breast cancer, but again, as I mentioned, a lot of these regimens also use hormonal preparations.

They could cause mouth dryness, which could cause some susceptibility to getting a yeast infection in the mouth or just cause soreness in the mouth. The hormonal preparations themselves can even cause an allergic type of a reaction in the mouth itself, leading to open sores in the mouth. Antibody-related treatments can also cause some mouth sores, and some of these antibody-related treatments, these monoclonal antibody-related treatments, can synergistically work with the chemotherapeutic agents. And used in connection, can actually lower the blood counts even further, making it, you know, more efficient, if you will, to cause different kinds of mouth sores

And then individual, targeted therapies of themselves that the drug itself can even cause mouth sores. So, it gets somewhat complicated in thinking about why people suffer with mouth sores during, you know, treatment for breast cancer, and as I already mentioned, there’s many treatments that are continuing to evolve and to be developed.

Jamie DePolo: What you said makes sense, because I know a lot of the targeted therapies, well, especially Herceptin, is given along with chemotherapy, as you mentioned. So, that sort of doubles the...I don’t want to say doubles the risk, but it just makes it more likely that somebody might get mouth sores, because they’re sort of working together to cause the problem.

Dr. Thomas Sollecito: Correct, and then did you want me to now answer how are they treated? 

Jamie DePolo: Yeah, and I guess I’m curious, too. Does the regimen that somebody is on, or the cause, affect the treatment, or are really all mouth sores sort of treated the same way?

Dr. Thomas Sollecito: No. No. No. That’s a really good question.

So, depending, really, on the cause of the mouth sores, would really dictate how they’re treated. So, if there’s an infectious cause, you really need to treat the underlying infection. So, let’s say there’s a viral infection or let’s say there’s a yeast infection. You treat those with, you know, conventional antiviral medications or antifungal medications.

If the ulcers are from low white blood count cells or low neutrophils or sometimes even low red blood cells, resulting in anemia, you can get ulcers that resemble the classic canker sore.

Often, the best treatment is palliation or a numbing agent or a coating agent. It’s not like you can make that go away very, very quickly.

But again, I had mentioned, you know, some people can almost get an allergic type of reaction, and if that’s the case, then, you know, first, the patient should probably discuss it with the oncologist to see if there’s an alternative, but you could even conceivably use a topical steroid preparation to help with some of the mouth sores.

And then the last is if mouth sores are related to dryness in the mouth, there are many, many over-the-counter products, which could make the mouth more comfortable by just rehydrating the mouth, and there is a myriad of different over-the-counter products. And I will caution the audience. Caution is maybe too strong a word, but I’ll remind the audience that just because one dry mouth product doesn't seem to help, well, my advice to my patients is just try another, because different people respond differently to the different types of over-the-counter products that improve dryness in the mouth.

Jamie DePolo: Oh, okay. Thank you for that. I’m curious. You talked about the allergic reaction, possibly, to some of the, perhaps, anti-estrogen or hormonal therapy.

Dr. Thomas Sollecito: Hormonal therapy, yeah.

Jamie DePolo: I guess I’m wondering, would that response or would those mouth sores look different than mouth sores, say, that are caused by low blood counts or mouth sores that just happen because of chemotherapy, and you know, do you need to find a dentist to help you understand that, or is that something an oncologist knows about? How would somebody go about sort of figuring out that?

Dr. Thomas Sollecito: And it’s a really brilliant question, and yes, different types or different cause of these oral sores can look different. Classically, can look different.

So, somebody that has an allergic reaction, their lesions in their mouth, most often, will look different than somebody who has low blood counts. Some of the viral infections look different than the fungal infections. Saying that, is when they are classically presenting, but unfortunately, sometimes they don’t present classically. So, it’s a little bit tough to distinguish one cause from another cause.

Now, that being said, the second part of your question is...or you know, are oncologists equipped to really decipher that. Some are, but again, when it’s difficult to really decipher when they’re not what we would expect or classic description of what we would expect as an oral ulcer, that’s really when you’re going to want to employ the help of an oral medical specialist or an oral oncologist. But again, many dentists, most oncologists, have seen many patients with these types of conditions, and when the lesions look classic, it’s pretty straightforward. When they’re not classic, it becomes more of a challenge, and that’s often when a specialist, like myself, would be involved.

Jamie DePolo: Okay. Okay. Thank you, and you sort of touched on this, but I’ll just make sure we didn't miss anything.

When we’re talking about dry mouth, you mentioned a lot of over-the-counter preparations. Is the cause of dry mouth kind of the same as it is for the mouth sores with the chemotherapy medicines, the low blood count, or is it another cause? I know it can be, perhaps, not as painful as a mouth sore, but it’s almost distracting when you try and talk and your mouth doesn't really want to work because it’s so dry.

Dr. Thomas Sollecito: Another very good question. Very complicated, unfortunately, to answer that question.

A lot of patients are taking multiple medications, both chemotherapeutic or medications to treat the breast cancer and otherwise. Medications are often the cause of having a dry mouth. Some of them have a direct effect on our salivary glands. Some have a little bit of an indirect effect on our salivary glands. So, depending on the medications that each or any individual patient may be taking, you need do take that into consideration as to what that case may be.

Per se, low white blood count or low red blood count may not be directly related to dry mouth, but if people have soreness in their mouth from oral lesions, they may not have the normal amount of PO or intake, whether that be drinking or eating, and then maybe have a little dehydration, which really compounds dry mouth significantly.

Jamie DePolo: Okay, and do those two conditions, I know just from the people I’ve talked to, they seem to often occur together, dry mouth and mouth sores. Is that common in your experience?

Dr. Thomas Sollecito: It is. It’s not exclusive, right? So, you can have people that have dry mouth and don’t have open mouth sores, and then you can have people that have open mouth sores that have enough saliva, but you are correct, that people that do have dry mouth, number one, they’re much more susceptible to developing a yeast infection in their mouth, particularly, again, if they’ve been on other chemotherapies, or if they’ve been on antibiotics because of maybe an infection somewhere else, because the white blood counts. So, their oncologist may want them on an antibiotic. Those are the people that are subject to these yeast or fungal infections of the mouth.

So, they sort of play on each other, meaning that, yes, the dryness makes them much more susceptible to getting a yeast infection. Diabetes is another great example of a comorbid condition. In other words, a diagnosis that the patient may have that’s underlying, that puts that particular breast cancer patient that’s undergoing all of this treatment for breast cancer at a much higher risk of developing a yeast infection in the mouth.

Jamie DePolo: Oh, okay. Very good to know. I did not know that. I do have one, perhaps, odd question for you. A couple people asked me this when they found out I was going to be talking to you. About oil pulling for mouth sores and/or dry mouth. What’s your take on that?

Dr. Thomas Sollecito: So, if we’re talking strictly evidence-based, it’s very difficult because I don’t know of very, very good studies that are done that can tell you if this is an evidence-based recommendation.

That being said, we also live in the real world where people are suffering, and they’d like to get some treatment. We will, typically, recommend, as a potential product to try, is rinsing with things like coconut oils, which can be soothing, or olive oil which can be soothing to the mouth and provide some level of lubrication in the mouth. Not a direct substitute for the saliva, but just to make the patient more comfortable. We don’t think of it in terms of treating an oral ulcer, per se, but we do think of it in terms of palliation, in terms of making people much more comfortable.

Jamie DePolo: Okay. Okay. That sounds good.

Infections in the mouth or abscesses around teeth. I know that’s probably less common than the first two, but it does happen. Obviously, I’m assuming, as you mentioned, the low white blood cell counts make somebody much more likely to have an infection. Is that a concern...I mean, I know it’s a concern, but because somebody is on chemotherapy, so they’re immune system is already knocked back a little bit. So, how do you treat that, because they’re getting chemo, but yet they have this infection in their mouth. How does that work?

Dr. Thomas Sollecito: You hit the nail on the head. So, it’s the medications that often cause these low blood counts that make a patient more susceptible to getting an infection, but remember, the infections in the mouth are usually things of preexisting issues that are going on with the teeth or the gums, and the other one that we see every now and again, in people that are undergoing chemotherapy are those people that get salivary gland infections, and some of those infections are actually quite serious.

Again, if people get dryness in their mouth and their saliva gets blocked off and that blocked salivary gland gets infected, it could be, like I said, a serious infection.

But getting back to the teeth and the gums, it is the medications that make a patient more susceptible to what is already existing, right, with a bad tooth or some bad gums, an infection that much worse, because the body can't fight that infection. A lot of times, that’s treated, you know, with an antibiotic. Sometimes it’s treated with some direct intervention if the patient is stable enough to have that intervention performed at that particular point in time.

But again, remember, it’s related to a preexisting...often, a preexisting dental problem that the patient’s having. And if a patient goes for a pre-chemotherapy — if they’re able in terms of time and fitting things in — examination before chemotherapy is started, theoretically, the risk goes way down, because you’ve potentially eliminated any infection before the chemo starts. Does that make sense?

Jamie DePolo: Yes, definitely makes sense, and it sounds like good advice.

And the last side effect I want to talk about, I know it’s rare. Osteonecrosis of the jaw, which is basically when the cells in the jawbone start to die off. I know that the bisphosphonates, which are used to treat osteoporosis, there is some evidence that one of them may have some breast cancer prevention/treatment effects.

So, they are used in people with breast cancer, but there was a study that recently came out that found that, actually, the rates of osteonecrosis of the jaw, while still low, were higher than had been thought in the past, and especially in people getting denosumab or Xgeva.

So, if you could explain a little bit, like, how would somebody know, perhaps, that’s happening, and then are there treatments for it? What can somebody do, aside from just stopping the medicine?

Dr. Thomas Sollecito: That’s a great question. So, you’re correct. Various medications used for breast cancer, and actually used for other types of cancers that have metastasized to the bone, and specifically, the bisphosphonates or the monoclonal antibody, like denosumab, which is what you had mentioned. In lower doses, which are also used for osteoporosis, have been associated with this condition of osteonecrosis of the bone.

Really, what’s going on in that situation is that the normal bone turnover cycle is altered by the use of these medications. And when there’s less bony turnover, these patients are more susceptible to getting necrosis or dead bone formation, and it, particularly, is associated in the jaws.

But remember, in those then patients...and I read that article. Let’s go back a minute because you asked a lot of different questions within that question. That article is a really well-done article. I reviewed that article. That article does suggest that the numbers are slightly higher than what were originally estimated.

Again, doing this type of, you know, epidemiologic data study like this, is challenging in and of itself, but I do believe that that’s probably correct. I mean, I think that’s what we’re seeing in our practices.

But it turns out, if you think about a breast cancer patient or a cancer patient in general, these patients have already been on, often, other agents, particularly, let’s take the metastatic breast cancer patient they’ve probably been through several cycles of either chemotherapy or hormonal agents, steroids while they’re getting the chemo.

So, they've been through other agents. They’re not treatment naive, and they seem to have a much higher incidence of developing ORN...or let me just say...not ORN. Let me just say MRONJ, osteonecrosis, not osteoradionecrosis. We’ll get to osteoradionecrosis in a second, but they do seem to have a much higher incidence of developing this osteonecrosis than patients that are taking these medications just for osteoporosis.

Now, if you think about it, some of these patients with breast cancer and metastatic breast cancer may have taken them, you know, at an earlier age for osteoporosis. So, there’s, again, some synergistic effect, some coupling, which, perhaps, in earlier studies, wasn’t really recognized, but now it is recognized. And so, the study to which you spoke, suggesting that the rates or the incidence, the rates of occurrence, of getting the necrosis of the bone is higher, still a low number, but higher, again, is very real. But it’s coupled with the fact that these patients, often, are not just naive, just getting this drug for the first time, or getting other drugs that synergistically make a patient more susceptible to getting osteonecrosis. As opposed to, let’s say, the osteoporotic patient where you’re using, again, the same drugs, different dosages, if you will, or different modes of infusion of these different kinds of drugs, you know, lower levels of these drugs, those patients often haven't gone through multiple cycles of chemotherapy. May not have been on steroids for a long period of time, et cetera.

So, again, I think this data’s probably correct, and it’s something that patients need to talk with their oncologist about. But it goes back to a little bit about what we were talking about before and that is, is that if you understand that, you know, dental procedures most commonly associated with this osteonecrosis, both in the cancer patient and even more remotely, in the osteoporotic patient, they’re associated with dental procedures involving bone, like extraction of teeth, implant placement, or having a dental infection.

It’s really that these triggers, if you will, are the triggering event for this complication to occur. So, if this could be done, like an evaluation or an extraction or an implant well before, then the patient’s much less susceptible to getting this necrosis. But it still can happen spontaneously. In other words, you don’t necessarily need to have bone manipulation or a dental procedure for osteonecrosis to occur.

And that, you know, our audience probably should discuss this with their dentist, but also their oncologist, and just be on guard that this is a potential complication, and it’s something that, you know, a patient may have to deal with. Most don’t, but some may have to deal with, and then make a decision with the oncologist. Most times, the decision becomes very clear that it is better to take these medications, albeit still have a low risk of developing osteonecrosis, but being mindful that, you know, there are things that you can do to treat it.

Jamie DePolo: Well, and that’s what I was wondering. So, what should somebody look for if they are on one of these medications? Are there any symptoms if this is happening?

Dr. Thomas Sollecito: Yeah, so, I think one thing that’s really important is that they see their dentist on a regular basis, and that means, clearly, before cancer treatment. Even during cancer treatment, not necessarily for an invasive procedure, but during cancer treatment and then subsequent.

So, patients can experience it a lot of different ways. They can experience just a spontaneous sequestration. Meaning that the bone sort of comes out the gums itself and flakes off into the mouth.

A lot of times, believe it or not, what we’ll see is the bone is a little bit sharp, and the mouth, from the chemo agents, are a little bit dry, and you get an irritation, and that irritation causes an ulcer in the mouth, and that may be the first sign. And then, of course, the first sign may be a deep pain in and around the tooth, which really isn’t the tooth, per se, but it’s actually the dead bone trying to make its way through into the surface, into the mouth.

Jamie DePolo: Oh, is that what happens when the bone dies? It tries to come out?

Dr. Thomas Sollecito: Yeah. So, what happens is, again, the term is called sequester, but it actually just tries to percolate out from the remaining healthy bone, and that’s the body’s mechanism, I guess, of trying to rid itself of that bad bone. And sometimes, it can get infected. So, it’s the classic signs of infection. Swelling, pain, separation, or pus, if you will, that’s what could be experienced.

Jamie DePolo: Okay. And then how would it be treated, especially in somebody who’s continuing cancer treatment? Are there options?

Dr. Thomas Sollecito: So, delicately, you know, because you really don’t want to have a treatment interruption. Most oncologists would agree that, you know, a treatment interruption is not a great thing. And I say delicately, because sometimes it’s antibiotic treatment, sometimes it’s antimicrobial rinses in and around, and let the bone sort of sequester on its own, maybe with a little bit of an assistance for an oral surgeon or a dentist, but again, gently

As the patient, hopefully, recovers from the chemotherapy and if there is still dead bone that doesn't seem to be clearing up on its down, then there are some interventions, like a debridement, if you will, of taking out the dead bone and then trying to get some closure of the tissue over the remaining bone that is alive. But again, when I say delicately, initially, particularly if they’re still having chemotherapy or having breast cancer treatment, you want to be judicious in what you’re doing, and oftentimes, antibiotic, antimicrobial rinses, gentle removal of spicules of bone, until the body sort of heals itself is the most product course.

Jamie DePolo: Okay. That makes sense.

And you’ve mentioned a couple of times about how important it is to see your dentist before you start chemo, definitely after, maybe during, we’re not sure. So, I guess I’m wondering if — that all sounds great for somebody who, say, has early-stage disease, and they know they’re getting, say, six rounds of chemo, and then they’re going to be done. What about somebody who has metastatic disease and say, is getting an infusion once a month for as long as it works. Is there some sort of set schedule that you would recommend or that you would like to see somebody on? Does it depend on the regimen? How should somebody approach that?

Dr. Thomas Sollecito: Another very good question.

So, it really is going to depend upon pre-existing dental health and dental disease. There are some folks that have really pristine mouths, you know, and had the ability to go to the dentist before, and they get the news about their breast cancer and treatment thereof. So, it’s really going to depend on the preexisting dental health or disease. And really, again, the timing of the needed treatment for the cancer.

So, there are some treatments of cancer that you might be able to postpone and then have the dentistry that does need to be done, done before the chemotherapy, but sometimes, that’s just not realistic. And so, if some of these patients do find themselves having chemotherapy with low platelet count or white blood counts, then, you know, unfortunately, the dental treatment may need to be postponed.

And then, of course, you could be put in a difficult situation where the patient’s in pain or the patient has an ongoing infection and you really do have to do something about it to take care of it.

But if that is the case, that’s probably something that the dentist and the oncologist need to decide with the patient to figure out what’s the best regimen, but in general, if the patient’s able, they should seek care for their general dentist or specialist before the chemo, during the chemo, and after, as well as if they’re having the chemo, you know, on a regular basis or have a discussion with the dentist that is with the oncologist to see when are the most opportune times.

If the patient’s blood counts are stable, most of the time, the dentist, you know, just like dental hygiene, dental prophylaxis can be done. Again, if we’re looking for a time limit, I think it’s really going to be based upon the historical level of their dental disease or their dental health, and then, usually, we’ll say follow up every three months or every six months or as needed if they develop something in between those two periods. Yeah.

Jamie DePolo: Sure. That makes sense.

And then, finally, I’m wondering how important is it for somebody to seek out an oncologic dentist? I know when I was thinking about doing this podcast, it was not the easiest specialist to find. I don't know how many there are. Most of them, it seems, are at large teaching hospitals or research facilities. So, I guess I’m wondering, are most general dentists somewhat familiar with this? People are going to get good care if they go there? If they have a question or they really want to see one, is there, like, a referral place? Would they talk to their oncologist?

Dr. Thomas Sollecito: Yeah, it’s a tough call. Usually, most dentists are equipped to see patients that, you know, are having oncologist treatment, that are having treatment. But I think it’s really important. We’re training dentists today, and we have for several decades now, of managing patients that have breast cancer or have even other types of cancers. But I think the key here is if we find ourselves in areas that are absent oral oncologists who are at major cancer centers, I think it’s really important that dentists work together with the patients’ oncologists to provide the appropriate and timely care that’s necessary.

It’s true that certain side effects of the chemotherapy may more efficiently be diagnosed and treated by an oral medicine specialist or an oral oncologist, but I will tell you that, you know, oncologists, during their training, as well, have recognized that there are oral complications, and usually, even in areas where there’s maybe not a major medical or major cancer center, or certainly, not an oral medicine specialist, it’s the discussion between the dentist and the oral oncologist, and they’re usually plugged into others in major medical centers or oral medicine specialists, that they can discuss these things that they’re seeing in their patient population.

So, again, it’s probably more of a collective effort in certain areas that don’t have the expertise, perhaps, locally. But a patient should be rest assured that their oncologist and their dentist do at least know what to look for and ask the questions that need to be asked and do have some resources that they can use that can afford the patient the best care that they can get.

Jamie DePolo: Okay. That is very reassuring to know, because I know some people were concerned they could not find an oral oncologist, an oncologic dentist in their area, but it sounds like dentists are experienced with that.

Dr. Sollecito. Dr. Thomas Sollecito, thank you so much. This has been so helpful and so informative. I really appreciate your time.

Dr. Thomas Sollecito: Great. Thank you, and I wish the audience the best.

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