Lifestyle Risk Factors and Breast Cancer Mortality

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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: Hello, I’m Jamie DePolo, senior editor at Breastcancer.org. I’m podcasting from the 2025 American Society of Clinical Oncology Annual Meeting. My guest is Dr. Samantha El Warrak, a hematology/oncology fellow at the Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine. At the conference, Dr. El Warrak presented her research on the impact of lifestyle factors on breast cancer mortality trends. She joins me to discuss the research. 

Dr. El Warrak, welcome to the podcast.

Dr. Samantha El Warrak: Hi, Jamie, thank you very much. It’s a pleasure talking to you today.

Jamie DePolo: So, before we get into the results, could you tell me how this study came about? What made you want to look at these issues? 

Dr. Samantha El Warrak: Definitely. Yes, that’s a great question. So, starting off my first year of fellowship at the University of Miami, as first year fellows, we have a dedicated Wednesday clinic every week to breast patients and we have renowned breast oncologists. And basically this sort of triggered my passion towards breast cancer a little bit more, and I wanted to look at not only the disease and the management and prognosis and treatment, but what we can do in terms of modifiable risk factors.

Because we don’t talk a lot about lifestyle changes when it comes to certain cancers because of the hereditary component involved. And I wanted to talk about or research a little bit more about what we can do from a [prevention] level in terms of the female population and how this can impact disease prognosis and mortality as well.

Jamie DePolo: Okay. And can you describe how you did the study? It looks like it was retrospective, you kind of looked back at records and things like that.

Dr. Samantha El Warrak: Definitely, yes. So, our study was mainly observational. We looked at the Global Burden of Disease [GBD] database. We wanted to basically explore certain risks, how they have evolved over time, and how they change across different age groups in terms of menopausal status, because that’s very important when it comes, when we talk about breast cancer in women. The Global Burden of Disease database is accessible to a lot of people, mainly the public, and instead of direct patient entry, direct patient data entry into the database, it basically sort of takes information from cancer registries across the United States, and that’s how we get the information. 

So, that’s mainly how the database is sort of built. So, we went in there, we looked at the Global Burden of Disease in terms of breast cancer mortality across the past 30 years, so from 1990 to 2021, and we saw what were the most common risk factors that were associated or were significant when it comes to mortality. Whether these were declining, whether these were increasing, and what we can do about them today in terms of our population.

Jamie DePolo: Okay and I just want to make sure I understand, this was just information from the United States, correct?

Dr. Samantha El Warrak: Yes, which is actually very important, because when we talk about certain risk factors, these can very much change when we look at other countries because they have different lifestyle habits, different dietary habits, so we would expect very different results as well.

Jamie DePolo: Okay. It was just when, when you said the Global Burden, I was like, oh, maybe I misunderstood. I thought this was worldwide, but it’s, but it’s no, it’s the burden of cancer in the United States.

Dr. Samantha El Warrak: Sure.

Jamie DePolo: Got it now. 

Dr. Samantha El Warrak: The database involves, basically it has data from all around the world, but we personally only looked at the United States using that database. 

Jamie DePolo: Gotcha. Okay, and so what were the results?

Dr. Samantha El Warrak: So, that is, that is the most interesting part basically about our study, and I’m happy to go a little bit more into detail. So, we looked, in general, we found the most significant risk factors that were associated with mortality were five, and these included alcohol, tobacco, high red meat diet, high fasting plasma glucose, and high BMI. Many of these risk factors are very well known among people that these are risk factors that can contribute to increased morbidity and mortality across different cancers, but our study found certain number variations and trends that were very impressive, basically. 

I can go into each one of them briefly, basically.

First of all, I’ll start with tobacco use. Tobacco use, interestingly, there was a dramatic decrease in age-standardized mortality rates across both pre- and post-menopausal women, which means less women were dying today from smoking, when it comes to breast cancer mortality, compared to how they were doing 10, 20, and 30 years ago. So, even though tobacco remains a very important risk factor associated with breast cancer mortality, less people are dying today from that when it comes to breast cancer than before. 

And this raises the question whether or not some public health campaigns are basically reaching some of these women better today than they were before, maybe some more campaigns are [existent] today than they were before. But what’s interesting is that there was a dramatic decrease of 58% in the pre-menopausal compared to 46% in the post-menopausal women. So, still post-menopausal women were still dying more today from tobacco-related breast mortality compared to the pre-menopausal women. 

Jamie DePolo: If I’m understanding this correctly, the women were dying from breast cancer, but tobacco played a role, so does that mean they smoked and then you’re tying the smoking to dying from breast cancer? I just want to make sure I understand that.

Dr. Samantha El Warrak: Yes. So, basically it would look at those women who were dying from breast cancer and what risk factors were more prominent in these women. Because we know that very significant risk factors that have to do with developing breast cancer in women, and this includes being on oral contraceptive pills, smoking, alcohol, obesity, having your period very early, or having, or achieving menopause very late, not having any children. We know breastfeeding is actually a protective factor, so all of these basically play a role.

Whenever we meet a new patient with breast cancer, we try to find out what their social history looks like so that we can draw a conclusion about what may have contributed to them developing their breast cancer. So, based on our hypothesis, this can, these cancer registries we’re drawing information on these women who were dying from breast cancer and what was the most commonly associated risk factor that was identified in their history.

Jamie DePolo: Okay, let me ask you one more that may be a dumb question. So, what happens if a woman had, say, ate a lot of red meat and smoked? How did you parse out which risk factor was more related, or how did you classify it? 

Dr. Samantha El Warrak: That’s a very interesting question because a lot of these women actually have overlapping risk factors, especially those with metabolic syndrome. Somebody who has diabetes or high fasting plasma glucose may also have a high BMI, so these are two contributing risk factors. We did not risk stratify our study based on whether they were like contributing collectively or whether basically this was just an individual risk factor, we just looked at each risk factor independently. But that’s a very interesting question and I think we can definitely look at that more in future research.

Jamie DePolo: Okay. Okay, great. Go ahead, sorry I interrupted you because I wanted to make sure I understood. 

Dr. Samantha El Warrak: Oh, interrupt me at any time and I’ll answer your questions as best as I can. But that’s for tobacco.

Alcohol also, interestingly, did the same trend as smoking, meaning there was also a decline in both pre- and post-menopausal women, so less women were also dying today from alcohol-related mortality. In pre-menopausal women, the age-standardized mortality rates from alcohol decreased by around 38% and in post-menopausal it also decreased by 13%, but you can see that 38 and 13 are pretty, there’s a difference there. 

So, post-menopausal women, it was also noted that they were having a slower decline in mortality compared to the pre-menopausal women, and this basically suggests that alcohol-related risks are still, are still rising due to changing patterns of consumption in the post-menopausal women.

What’s also interesting is that even though less people were dying today, less women were dying today from alcohol consumption, more people are drinking alcohol. And in that subset of people who are drinking, they still have a higher related mortality compared to those who are not drinking.

So, they remain very strong risk factors and they are even stronger risk factors today than they were before, but also when you look at the population in general for 100,000 women, which is what we looked at, they were dying less compared to before. And this also raises a lot of questions about what lifestyle interventions are being implemented in our clinics and in our community.

Number three, high fasting plasma glucose, for the pre-menopausal women mortality from high glucose increased by 6.3%, but in the post-menopausal women there was a more pronounced increase of 9.7%. So, this reflects a stronger association between high glucose and breast cancer mortality in older women.

And this raises the question, begs the question, what’s happening in women who are post-menopausal in terms of their metabolic syndromes? Are more people getting diagnosed with diabetes? Do more, are more post-menopausal women sicker because of the aging nature of the population? What’s really going on in post-menopausal women? How is fat contributing to increased mortality because of high fasting plasma glucose? And this is all areas of future research. We’re currently writing the manuscript and I’m very excited about going into detail about why these findings, basically, why we have these findings, and I’ll be more than excited to share with you what we find in the future. 

Number four is high BMI. High BMI was a very striking result in the pre-menopausal women. In fact, it was the only risk factor that’s on the increase compared to all five. So, all these risk factors, we can see there was a decline in age-standardized mortality rate, but for the high BMI in pre-menopausal women, there was a dramatic increase in BMI-related mortality, up to 600%. So, more younger women today are dying from high BMI and that’s a very interesting finding. This is all breast cancer mortality-related. 

Jamie DePolo: Right and that, and that risk factor was increased.

Dr. Samantha El Warrak: Correct, high BMI in younger women today was contributing to more breast cancer-related deaths than it was before. Why is high BMI today more of a problem than it was years ago? And we can imagine there are so many different answers to this in what can be really contributing, and what, what are younger women eating today compared to what they were before? How is their lifestyle, whether it’s sedentary, whether it’s lack of physical exercise, whether it’s different physical conditions that are possibly contributing to high BMI today than it was before?

And finally, is the diet high red meat. So, the age-standardized mortality rate for high red meat consumption also decreased from 1990 to 2021, but it was still the most common risk factor that was associated with breast cancer mortality. And in fact, in 2021, a high red meat diet, which basically is defined as consuming more than 70 grams of red meat per day, it was the leading risk factor for breast cancer, age-standardized mortality rate overall, contributing to 14% compared to 86% from all other risk factors. 

So, even though that, even though deaths related to red meat was going, was on the low, maybe more people are adopting vegetarian diets today, but it’s still considered the most contributing risk factor to breast cancer-related mortality, in the United States at least. So, these were mainly the five risk factors that we looked at because they were the most significantly associated with breast cancer-related mortality across the past 30 years. 

Jamie DePolo: So, I have a question about BMI because we know that it’s, a lot of times it’s used as a stand-in for having excess weight, but we also know that it’s a very imperfect measurement, especially among different ethnicities, among people who maybe have a lot of muscle mass that work out all the time. So, how do we kind of reconcile that with this? I know there’s no new standard measurement that is used and that, and that’s why it continues to show up in studies. But I guess I’m wondering, what are your thoughts on that? Like, does this, does this change the interpretation of the research at all? Or how do you think about that? 

Dr. Samantha El Warrak: That’s actually a very good question because I’m with you on this. In fact, many endocrinologists and nutritionists today are not even looking at BMI anymore when it comes to their patients because of what you, what you rightfully said, sometimes the muscle mass contributes, different people have different, different muscle masses, and it doesn’t directly tell you whether or not somebody is obese, morbidly obese, overweight. 

Now, the standard definition of high BMI or at least, let’s say, being overweight is BMI over 25, being obese would be BMI over 30, being morbidly obese would be over 35. So, that’s what we all know, but today many endocrinologists and nutritionists are not using this definition anymore.

Now, when it comes to our database, I must say it only describes high BMI. We weren’t really able to tell what they actually meant by high BMI. Are they gathering data from overweight, and obese, and morbidly obese? Or is it just obese women? What are we really talking about here? Is it BMI over 25? Is it BMI over 30? 

We weren’t really able to tell exactly what they meant by high BMI, and I think this is a very interesting discussion. Because what we can also do is look at previous GBD database and research studies to try to find out what they actually meant by high BMI, because this is important. This is very important. Unfortunately, I would have to look into that a little bit more, but for now, we don’t really know what they meant by high BMI, but we can, it’s safe to say that BMI over 25 would start posing a risk factor. 

Jamie DePolo: Okay.

Dr. Samantha El Warrak: The higher you go, the higher, the higher the risk, for sure.

Jamie DePolo: Okay. And then the other thing I’m wondering, some of this information like smoking, alcohol consumption, how much red meat one eats, I’m assuming that was all self-reported. And I always have an issue with self-reported information, especially if somebody knows, say, it’s for a risk study because they may, I’m not saying they, somebody would do this on purpose, but remembering how much you drank, how much you ate, especially if somebody says, “How much red meat did you eat in the last six months?” I myself would have no idea how to figure that out, I would just make something up. 

So, to me, I guess I’m wondering does that, is that an issue for some, for studies like this? And it’s also my issue with some of the nutrition studies because in the past, I mean this is not related, but there was a study that said women who drank milk when they were teenagers had a higher risk of breast cancer. And I’m like you’re asking somebody who is 55 to remember how much milk they drank when they were 13? I kind of have a problem with that, but that’s just me. So, how do we, how do we interpret the data thinking about that, too? 

Dr. Samantha El Warrak: So, that’s very important, the issue that you raise, and this is a problem whenever we’re trying to measure or have an idea about how much a lifestyle risk is contributing to disease. So, unfortunately, most of the time we have to take the patient’s word for it because there is no exact metric to measure how much somebody is smoking or drinking. For drug use, there is a way to do a UTOX to really see whether or not a patient is truly endorsing any substance use, you can do some blood tests as well to see if a patient had a certain exposure to other metabolites. 

But when someone is eating red meat, or when someone is smoking or drinking, we don’t really have a way to tell exactly how much of that they’re doing, we have to take their word for it. It’s my understanding, though, I don’t think any of these patients, they were told that this is a study about risk factors. I think this was information collected from all the cancer registries because whenever a new patient comes in and sees her doctor, she will be asked about lifestyle intervention. She will be asked whether you smoke or you don’t smoke, whether you drink or you don’t drink, not because they’re trying to gather information for a certain risk factor study, but just to establish care. So, that bias, I think, would not be there during an initial encounter.

And even in subsequent encounters, when they come for their follow-up visits, when they’re getting chemotherapy, during disease progression or even during surveillance, these questions do come up. Hi, ma’am, how have you been doing? Are you still smoking? Are you still drinking? How is your diet looking like today?

So, when these women know that this is regarding their own care, they do tend to tell the truth in that situation. But I do agree that if they had known that this is maybe because of study purposes, maybe they would skew the, the, their, their reports basically according to what they want. But we’ve got to, we’ve got to take their word for it, but I understand there is definitely this concern. 

Jamie DePolo: Yeah. No, and I don’t mean to suggest that anybody would purposely lie, but just, you know, remembering how much over a time period can be difficult.

Dr. Samantha El Warrak: Definitely. Definitely, yes, I agree, especially, especially with sicker patients sometimes they have metabolic encephalopathy, which means they’re confused. Sometimes they have brain disease, sometimes they’re altered, sometimes they’re getting sicker. And these are patients who you cannot completely rely on what they’re saying to you, sometimes you’ve got to depend on family members, on caretakers, and they don’t always have the information. So, I do agree. 

Jamie DePolo: Yeah, okay. So let’s put this in context. What does this study mean for women who have been diagnosed? And I guess I also want to ask too, I know so many women when they get diagnosed the question is, what did I do? What did I do wrong? And so, I’m also a little bit protective when studies like this come out because I don’t want people to feel blamed for their disease that they clearly didn’t have a whole lot of control over. So, if you could put the results in context for us, what does this mean for people who have been diagnosed?

Dr. Samantha El Warrak: Well, thank you, Jamie, very much for that question because I think it’s important for women to, for the takeaway message today to basically tell them what we can do or we can’t do. First of all, this study, this observational study, talked about or looked at risk factors that had to do with who was dying from breast cancer, not who was developing breast cancer. I’m not saying there isn’t any direct relationship because there is, but we didn’t look at that in our study. We were talking more about who was dying from breast cancer. 

So, for those who have already been diagnosed with breast cancer, what, what can I do? First of all, this has to do with the age group that you fall into, whether you’re pre-menopausal and that we define it as being 20 to 54, or post-menopausal, which is above the age of 54, and even that we have to take with a grain of salt because a lot of women achieve menopause way earlier than that as well.

Jamie DePolo: Right.

Dr. Samantha El Warrak: So, we’ve got to be careful how we’re describing our menopausal status and what the age, what is the age group that they fall into. And what can I do? What lifestyle interventions can I add? Because a lot of times when a woman is diagnosed with breast cancer, we tend to become reliable on our physician, how are we diagnosing, how are we treating, what pills am I going to take, what chemotherapy am I going take? Am I going to be on surveillance? Am I going to need scans? But sometimes the patients also want to feel that they’re responsible and they’re in control of their care as well. 

Therefore, these findings will help the woman realize that I can also implement some changes on my own personal level and in my own lifestyle as well.

So, the fact that mortality is decreasing over the past 30 years says that there is something that is being done right today, and we have to look at what that information is. Is it because there is more information available on the Internet? Is it because there is greater health, there is better healthcare campaigns right now? And why is it more important, and why, why is this decline more significant in pre-menopausal and younger women compared to the older women? 

Is it because younger women have access to these resources a little bit easier and better than the post-menopausal women? Do they have access to the Internet? Do they have access to podcasts or meetings? Or do they travel more and meet other friends and other groups who are, who are suffering from the same things compared to older women? What is being done? 

And I think looking at risk factors like high plasma glucose or high BMI and how they’re contributing significantly today, it begs the question, do we need to implement in our primary care clinic, or when a woman gets her yearly physical with her doctor, do we need to start looking at these numbers, not only as a cardiovascular screening, cardiovascular health screening, but as breast health as well?

Like, let me look at your cholesterol levels, let me look at your sugar levels, let me look at your BMI numbers, not because I want to risk stratify you according to your cardiovascular health, but as your breast cancer health as well, or as your breast health in general.

So, I think these would help women to implement these changes early on in their life, take note of them early on in their life, not only as gaining weight or having a heart attack or having heart failure, or having a stroke, but also breast cancer-related as well. So, I think this is, this is what I would say would be an important takeaway message from our study. 

Jamie DePolo: Okay, and then one final question. You had five risk factors, some were more related than others. If somebody is listening right now, they’ve been diagnosed, and maybe they have the capacity to make just one change. Is there one of these factors that you would say is maybe more important than the other? I don’t know, maybe it’s not, but if somebody were looking to do one thing, would it be eat less red meat? Drink less alcohol? What, is there, would you pick one? 

Dr. Samantha El Warrak: So, I would. Again, when it comes to our study alone, what we have found is the greatest risk factor that we found associated with breast cancer mortality, as of 2021, was high red meat consumption. So, this was the most prominent finding compared to the others when it comes to the patients who were dying from breast cancer. So, yes, I would say a diet that is high in red meat consumption was the most contributing factor, and if you were to maybe implement one change, I would recommend that. However, and this isn’t breast cancer-related, I wouldn’t suggest you continue to smoke while reducing your high red meat consumption because you’re definitely increasing your risk of developing other cancers and other diseases. 

But when it comes to breast cancer mortality, if you’re a woman who is newly diagnosed, if you don’t smoke and you don’t drink and you are not overweight or basically your BMI is considered average or below average, and everything else just falls into place, but you eat a lot of red meat, then definitely I would suggest that you can reduce that. 

Jamie DePolo: All right. Dr. El Warrak, thank you so much for joining us. I appreciate your insights.

Dr. Samantha El Warrak: Thanks so much, Jamie, it was a pleasure today. 

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