Diarrhea — Breast Cancer Treatment Side Effects

This podcast is made possible by the generous support of Lilly Oncology.

Jamie DePolo: Hello everyone, welcome to this edition of the Breastcancer.org podcast. I’m Jamie DePolo, the senior editor at Breastcancer.org. Our guest today is Dr. Brian Wojciechowski, who is Breastcancer.org’s medical adviser. He practices medical oncology in Delaware County, Pennsylvania at Riddle, Taylor, and Crozer Hospitals. A proud native of South Philadelphia, Dr. Wojciechowski trained at Temple University School of Medicine and Lankenau Medical Center. His research has been presented at the San Antonio Breast Cancer Symposium, the world’s largest scientific meeting on breast cancer. Dr. Wojceichowski is a sought-after speaker on the topics of medical ethics and the biology of cancer.

Today, we’re going to talk about a topic that many people are interested in, but not everyone really wants to discuss or talk about out loud, which is diarrhea. So, Dr. Brian, welcome to the podcast.

Brian Wojciechowski: Thank you, Jamie, it’s great to be back.

Jamie DePolo: So, to start, you know we get a lot of questions about diarrhea as a side effect on our Discussion Boards, so let’s start with the basics, so to speak. Which breast cancer treatments are known to cause diarrhea?

Brian Wojciechowski: Jamie, I would say that any intravenous chemotherapy has the potential to cause diarrhea. So, drugs like Adriamycin, Cytoxan, Taxol -- those are probably the most common intravenous chemotherapy drugs given to women in the United States. They can all cause diarrhea, although it’s not particularly common. I would say among the chemo drugs that would be the most troublesome in terms of diarrhea would be 5-fluorouracil, otherwise known as 5-FU, or its oral counterpart, Xeloda, which is also called capecitabine. And with those drugs, the rate of diarrhea can be up to 50%. Now, that doesn’t mean it’s severe diarrhea, but I would say about half of all women that I treat with these drugs end up with some degree of diarrhea. We’re not giving a whole lot of 5-fluorouracil anymore in the United States, but if anybody’s listening internationally, I think it’s more common to give that drug in the early-stage setting overseas. Xeloda, or capecitabine, are usually given for metastatic disease in the United States.

Jamie DePolo: Now, some of the targeted therapies I believe, too, are known to cause diarrhea, in some cases severe. Is that correct?

Brian Wojciechowski: That is true. Any of the what we call “small molecule drugs,” such as lapatinib or pazopanib, can certainly cause diarrhea. Even some of the targeted therapies that are given intravenously, like Herceptin and drugs like that, can also cause diarrhea.

Jamie DePolo: Okay. So, it’s a fairly common side effect. Do we have any idea how common it is? I mean, is there an estimate of women being treated for breast cancer who experience this side effect?

Brian Wojciechowski: I would probably say it’s probably around 5% who get severe diarrhea, and when I say severe, what I mean is diarrhea that ends up requiring intravenous fluids in the office or hospitalization.

Jamie DePolo: But what about the less severe where it’s happening -- it’s not severe, but it’s annoying?

Brian Wojciechowski: Yeah, that would be up to 50% with some of the drugs.

Jamie DePolo: So, that’s pretty high?

Brian Wojciechowski: Yeah, I think it is. Yeah. And you know, even one or two or three episodes of diarrhea a day can be very distressing and can be enough to totally ruin your day and keep you in the house or what have you.

Jamie DePolo: Absolutely. Too, I guess I’m curious, does the diarrhea last the entire time someone’s on those treatments? Like for capecitabine -- is that the whole time, or is it that it’s when you start that treatment, it’s kind of bad, but then it tapers off? Does that happen at all?

Brian Wojciechowski: Well, it’s very unpredictable. Honestly, if there’s any pattern that I’ve noticed, it’s that the more cycles of chemo that a patient gets, the more diarrhea they tend to get. So, it seems like the effect builds up. Now, there’s probably as many different types of diarrhea as there are types of chemotherapy drugs, so it’s important to remember that not all diarrhea is created equal. And so depending on what’s actually causing it, it could happen really at any time.

Jamie DePolo: So, explain to me a little bit more what you mean by that, where it’s not all created equal. Meaning that it’s caused by something else besides the chemotherapy, or it’s a combo of things?

Brian Wojciechowski: Diarrhea is often caused by a viral syndrome, so gastroenteritis, and that can happen literally at any time. Food poisoning. Sometimes it’s as simple as taking lactose out of a diet, or taking something out of a diet that is wreaking havoc on the gut or mixing improperly with the chemotherapy. Some of our patients may be on experimental treatment with immune checkpoint inhibitors -- so, drugs that rev up the immune system to fight the cancer -- and those can actually cause a very dangerous form of diarrhea that’s an autoimmune colitis, and that tends to happen about 8 to 12 weeks into treatment. So, it’s quite variable, and there are many different causes for the diarrhea, and it’s not always the anti-cancer drug.

Jamie DePolo: Okay. So, in some cases, too, I know when a person is on chemotherapy that’s knocking back their immune system, so they may be more prone to get some of those illnesses that you’re talking about that can also cause diarrhea.

Brian Wojciechowski: That’s true, and more prone to complications from the diarrhea.

Jamie DePolo: Now, are there certain people that are just at a higher risk for experiencing diarrhea during treatment? Are there any characteristics?

Brian Wojciechowski: Yes. One thing that I’ve observed is that sometimes it's just a matter of taking dairy products out of somebody’s diet, and that clears up the issue. So, I would say anyone who is known to have a lactose sensitivity may be more prone to diarrhea. People who have a history of surgery on the bowel, particularly if part of the bowel has been removed, are going to have more diarrhea. And at least in terms of the drugs Xeloda and 5-fluorouracil, a small percentage of patients actually have an enzyme defect, which will cause them to get massive diarrhea once the drug is started.

So, there’s a lot of different factors and patient characteristics that might predispose you to diarrhea. The important thing really is that diarrhea needs to be reported. I would encourage patients to keep track of their diarrhea in terms of the quality -- is it watery, is it just soft stool -- and also, it’s very important to keep track of the number of times per day, because all these go into how severe it is and how we manage it.

Jamie DePolo: I guess I have two questions now. So, we’ve talked about what it is. Are there things people can do -- I know you mentioned avoiding dairy products, in some cases -- so, are there things people can do to prevent diarrhea or lessen the severity, and then what are the treatments for it?

Brian Wojciechowski: Sure. So, like I said before, sometimes it’s just a matter of taking the lactose of the dairy products out of the diet, and sometimes that clears it right up. Sometimes you need to hold the medication, if you’re on a pill or if you’re on chemo, the doses may need to be modified -- but, in that case, you have to notify your physician, obviously. There’s the old BRAT diet, which is a staple among nurses, it's when you tell people to eat toast and bananas and applesauce and rice, and those foods can decrease diarrhea. And then, what was the next question?

Jamie DePolo: Oh, just as far as treatments, I mean it sounds like there a lot of potential causes. So, are there a lot of potential treatments, or are there some pretty standard treatments that are used?

Brian Wojciechowski: Yeah, the treatments that we probably go to the most would be things like Imodium (chemical name: loperamide), which is available over-the-counter. If Imodium doesn’t work, we go with something called Lomotil, which is actually a prescription medication -- it’s actually a weak narcotic, so it requires a doctor’s prescription. In cases where those two medications are ineffective, then there’s actually shots that can be given -- somatostatin. And there’s other interventions, depending on what’s causing it and what drug patients are taking. So, a drug called Carafate has been used. Cholestyramine, which binds the bile acids. So yeah, there’s a lot of different treatments but, again, it all depends on what’s causing the diarrhea and how much diarrhea a patient is having.

Jamie DePolo: Well, that’s good. And I want to know -- I know you said in some cases, like if Imodium doesn’t work, there are other options -- but in most cases, are the treatments effective?

Brian Wojciechowski: Yes, actually diarrhea is usually pretty easy to manage, believe it or not. The problem is, is that a lot of times patients aren’t reporting it, and I’m not sure why… I’m not sure. Maybe they think it’s not related or they think it’s not severe enough. But, as long as the patient reports it in a timely manner and we get on it early, we can usually manage it effectively with those drugs and interventions that I listed.

Jamie DePolo: Well, that’s very good to know. So, the take-away for people is: if you are experiencing diarrhea, definitely tell your doctor, and there are treatments that can manage it, ease it, and make you feel a whole lot better?

Brian Wojciechowski: Exactly.

Jamie DePolo: And I have one last question for you -- you kind of hinted at this, that in some cases diarrhea can be very serious -- what would lead you to believe diarrhea is serious? Is it the frequency? Is it weakness in the patient? When should someone be concerned?

Brian Wojciechowski: I would always advise a patient to report when they are having diarrhea -- any amount of diarrhea -- while they’re on treatment. But, in terms of emergency, and in terms of what warrants a call in the middle of the night, I would say: if there’s fever involved, if there’s blood in the stool, if there’s severe abdominal pain or if the belly becomes very bloated, or if the person becomes unresponsive or confused -- all those things could be a sign of a serious problem, and I would consider that to be a medical emergency. Time to wake up the doc in the middle of the night or even go to the emergency room.

Jamie DePolo: Okay. All right. Well, thank you so much, Brian. This has been so helpful and again, not the topic that everyone wants to talk about over breakfast, but certainly an important one, and I think this has been some helpful information.

Brian Wojciechowski: It’s been my pleasure, Jamie.