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Getting to the truth around HRT and breast cancer with Dr Avrum Bluming

Leading US oncologist Dr Avrum Bluming joins Dr Louise Newson to talk about the crucial role of oestrogen in women’s health.

Despite HRT’s proven benefits in protecting against heart disease, bone fracture and cognitive decline, many women still avoid it over breast cancer fears.

It’s been more than 20 years since media headlines about a study called the Women’s Health Initiative linked HRT to an increased risk of breast cancer. In this podcast, Dr Bluming says that in fact we now know oestrogen alone decreases the risk of breast cancer development by 23% and risk of death from breast cancer by 40%. 

He also disputes the findings of the WHI study that combined progesterone and oestrogen HRT leads to a small increase in breast cancer cases.

‘It is very upsetting when such an influential study continues to misquote their own data,’ says Dr Bluming, who has spent 25 years studying the benefits and risks of HRT in breast cancer survivors.

Dr Bluming points out that oestrogen used to be a treatment for breast cancer before chemotherapy was developed, and that rates of breast cancer increase as we age, despite the fact our oestrogen levels fall as we get older.

You can read about Dr Bluming’s latest paper here, and listen to an earlier podcast Dr Newson and Dr Bluming recorded here.


Dr Louise Newson: [00:00:11] Hello, I’m Dr. Louise Newson. I’m a GP and menopause specialist and I’m also the founder of the Newson Health Menopause and Wellbeing Centre here in Stratford-upon-Avon. I’m also the founder of the free Balance app. Each week on my podcast, join me and my special guests where we discuss all things perimenopause and menopause. We talk about the latest research, bust myths on menopause symptoms and treatments, and often share moving, and always inspirational, personal stories. This podcast is brought to you by the Newson Health Group, which has clinics across the UK dedicated to providing individualised perimenopause and menopause care for all women. So today on the podcast, I have someone who is in the US, so not near me, but I’ve had him on my podcast before and I’ll hopefully have him again. Someone called Avrum Bluming, who some of you might have known, who is a very inspirational and academic doctor who has got the most amazing knowledge and also clarity about things. And I first heard him talk at the Royal Society probably about seven years ago and thought, wow, this is so interesting because he’s saying some really common sense things and common sense often gets lost in medicine. We’re always trying to find the biggest, the best, the most impressive cure for something. And then we forget basic science and Avrum’s talk at the Royal Society just made me sit and reflect and think, Louise, what are you doing? Go back to basics in medicine, which is what we often do. So he’s helped me more than he knows over the last few years, really trying to unpick evidence in a very simple way. So I’m very delighted, Avrum to introduce you again to the studio. So thanks for joining me. [00:02:09][118.5]

Dr Avrum Bluming: [00:02:10] It’s a pleasure, Louise, as always. [00:02:11][1.5]

Dr Louise Newson: [00:02:12] So yours and my background are similar, but different in that you’ve been an oncologist for many years and I wanted to be an oncologist, and the only reason I changed was really for family reasons, just because, I just, with my husband being a surgeon, I thought, actually I want to work part time. And in the nineties, when I had to make career choices, after I’d done all my medicine exams, it was too difficult to go part time as a doctor then. So I’m always jealous of people that are oncologists. But actually I think I don’t regret what I do in the slightest. But you’ve written the most amazing book that many of my listeners would have heard of, and if they haven’t, they should look it up called Oestrogen Matters. And this is something that even the title actually, Avrum. Oestrogen is something everyone seems to be really scared of and actually oestrogen, can you just explain, it’s just a hormone in our bodies, isn’t it? [00:03:07][54.6]

Dr Avrum Bluming: [00:03:07] Yes, it is. Both male and female. Yes. And I gave a talk last week that you and I were just discussing in front of several hundred perimenopausal women. And I was aware that they were afraid of hormone replacement therapy and oestrogen specifically. And I asked them, what is it about hormones that you’re afraid of? And I put several options in front of them. I said, are you afraid of heart disease? And very few of those several hundred hands went up. Are you afraid of hip fracture? And very few went up. Are you afraid of cognitive decline? And a few more went up, but not many. And then I said, are you afraid of breast cancer? And almost all of the hands went up. Well, I am a medical oncologist. I have spent the last 50 plus years working with patients who have cancer, and 60% of my practice has been women with breast cancer. So I’m very familiar with that entity. In addition, my wife had breast cancer. My daughter had breast cancer. My wife’s sister was just diagnosed with breast cancer. I’m very grateful that all three of them thus far are in excellent health. But I’m very aware of the fear surrounding breast cancer, both as a patient and as a physician. And you mentioned the Women’s Health Initiative. The Women’s Health Initiative, as you well know, and many of your listeners know, is a 1 billion plus dollar study that was initially published in July of 2002. And that really put a target on hormones, a target that has been fired at many, many times. The prevalence of hormones in the United States fell from about 44% of the eligible population to less than 5% where it remains today. And the major fear was breast cancer. And so at your discretion, you let me know when you want us to get into that, and I will gladly get into that. [00:05:44][156.2]

Dr Louise Newson: [00:05:44] Well, let’s get into WHI in a minute. But before we do, let’s just talk about what a hormone is, because actually, some people think hormones are only oestrogen and the sex hormones, but we’ve got lots of different hormones in our body. And they’re just chemical messengers, aren’t they? Can you just elaborate what a hormone actually is? [00:06:02][18.4]

Dr Avrum Bluming: [00:06:03] Sure. I wouldn’t say just because I think they are miraculous chemicals. They are the chemicals that circulate in our bloodstream and go from the organs, secreting them to the organ receiving them, and tell the receiver organ what to do, when to grow, when to multiply, when to stop growing, whether you should secrete a certain product, whether your heart should increase its rate of beating per minute in response to exercise. Hormones are wonderful. The hormones that we talk about most specifically in women are oestrogen, which is a hormone that has now been shown to be responsible for many attributes of women that make us recognise them as women, but they also help decrease the risk of heart disease among women as they get older, decrease the risk of hip fracture among women as they get older, preserve the ability to think clearly and also prolong life if they’re started within ten years of a woman’s final menstrual period. We use one additional hormone, and I’m sure most of your listeners are aware of this, oestrogen alone can increase the risk of uterine cancer. And so women who still have a uterus when they are given oestrogen are also given progesterone, which is a hormone that prevents that increased risk of uterine cancer among women taking oestrogen. So when we talk about hormone replacement therapy, we’re talking largely about oestrogen and oestrogen plus progestin, progesterone, when a woman still has a uterus. [00:08:11][127.7]

Dr Louise Newson: [00:08:12] And progesterone has its own metabolic effects in the body as well. It’s an important hormone for many women, but we’re just sticking to oestrogen. We know that every cell responds to oestrogen and actually our ovaries produce oestrogen, but our brain produces oestrogen. And I’m sure other areas of our bodies produce oestrogen as well, don’t they? [00:08:32][19.9]

Dr Avrum Bluming: [00:08:32] Yes, they do. And oestrogen has a 640 million year history. It is present in octopuses, which go back that far. And for those of you who think I mispronounce the plural of octopus, I didn’t. It is octopuses. [00:08:53][21.0]

Dr Louise Newson: [00:08:55] They’re very interesting because as you know, and some listeners know, I’ve got a pathology degree as well, and we learned a lot about the role of our immune cells to fight infection, but also to fight disease. And as soon as I started to read more about oestrogen, knowing how we’ve got receptors for oestrogen on all our immune cells, and actually when we have low oestrogen in our body, it increases inflammation and also the way our cells work. As you say, our cells are so important, but we have mitochondria in the middle of our cells, which is actually like the powerhouse of the cells, isn’t it? It sort of works out the whole energy and determines how so many processes occur. And we know that oestrogen is very important for mitochondrial function as well as the immune cells, as well as lots of other processes in our body and as you say, in our brains. It works as a neurotransmitter, a really important chemical to allow our brains to work. So there are lots and lots of benefits. And we know actually for many years, haven’t we, in studies that women who have regular periods, women who are naturally producing oestrogen, are healthier than women who don’t have their periods. So, I mean, we’ve got some good studies from women who’ve had their ovaries removed. Their risk of disease actually increases quite quickly after and even my really non-existent menopause training as an undergraduate in the eighties, I was still taught that women are protected from various diseases, including heart disease, usually up until the age of 50, and then something happens. And that’s something obviously is the menopause. But they failed to tell us that. Then women catch up with men afterwards and their risk of heart disease and so forth increases. So this is why I’m talking at the start about this common sense medicine, really, isn’t it? Because oestrogen is really important when we have it naturally in our bodies, isn’t it? [00:10:52][116.8]

Dr Avrum Bluming: [00:10:52] And it’s not just theoretical, but women who have their ovaries taken out early or women who reach an unusually early menopause have increased risks of heart disease and bone fracture and cognitive decline. And giving them oestrogen eliminates that increased risk and helps prolong life. Yes. [00:11:15][22.6]

Dr Louise Newson: [00:11:16] Which makes sense, isn’t it? You know, in medicine, we try and replace what’s missing. And so if we know something is missing, we replace it and it improves. And also, lack of oestrogen can cause so many symptoms that we’ve talked about quite a lot before that are associated with the perimenopause when hormones start to decline and also the menopause. So I sometimes think which, just bear with me here, Avrum, if I was an alien from outer space and I knew nothing about the WHI, had read no adverse media about HRT, hormones or oestrogen. And I was listening to this conversation, I would then be probably asking you with my inquisitive mind. So. Right. So why aren’t we just replacing everyone with oestrogen? Because it’s a really important hormone. Women live a lot longer than they used to 100 plus years ago. We used to die earlier, so now we’re living into our seventies, eightes, nineties if we’re lucky. But a lot of time without hormones. We’ve just been talking how good it is as a biologically active hormone. So Avrum why are we not all taking oestrogen then? [00:12:23][66.6]

Dr Avrum Bluming: [00:12:23] Well, first at least half of us are males and we have problems taking oestrogen. So let’s focus just on the females among us. And if you were an alien, you might have seen the headline on The New York Times. If you were smart enough to get to Earth, you probably got The New York Times or the London Times, and you would have seen that there was this very expensive study that was looking to determine whether giving oestrogen to women as they pass the menopause line would help them. And the study first came out as a press conference, which is unusual. Usually a study is published in a medical journal. Healthcare providers have a chance to read the study and form an opinion. This time before it came out in the Journal of the American Medical Association, it was widely published in news media around the world. And what they said in the results of the study is that it increased the risk of heart disease, increased the risk of cognitive decline and increased the risk of death. They have walked back all of those and said, well, in fact, if it started around the time of perimenopause or within ten years of a woman’s final menstrual period, it actually improves all of those things. At the same conference in 2002, they said it also increases the risk of breast cancer. And that was the leading headline. Interestingly, at that time, it had no increased risk of breast cancer found to be statistically significant. But that didn’t prevent the press conference and the news media to widely publicise that. At that same time, the Food and Drug Administration in the United States issued what is called a black box warning that says if you take this, any product containing oestrogen, it will increase the risk of cancers and specifically breast cancer. We now know because the Women’s Health Initiative has published updates many, many times since then, and here we are 21 years later, and now we know that oestrogen they found and this goes along with other researchers as well. Oestrogen alone decreases the risk of breast cancer development by a statistically significant 23%. And even more importantly, it decreases the risk of death from breast cancer by 40%. That FDA black box warning is still in place. There is a movement among several scientists here in the states to change that, but it is still very much in place. The Women’s Health Initiative now says that, well, it’s the combination of oestrogen and progesterone that increase the risk of breast cancer. And in fact, what their data say is for women who start oestrogen and progesterone around the time of menopause or within ten years of the last menstrual period, the combination does not increase the risk of breast cancer. The population they studied was a population with a median age of 63. Many of them were considerably, half, were considerably older than that, and that hasn’t been widely circulated. Even if they were right that the combination of oestrogen and progesterone increases the risk of breast cancer, the increased risk would be one per 1,000 women taking it per year. And it doesn’t increase the risk of death from breast cancer, although they still claim that it increases the risk of breast cancer development. And in fact, even that claim is challengeable. What the paper I just published within the past few weeks says is there was no increased risk among the population that took the combination of oestrogen and progesterone, regardless of when they started taking it. That, in fact, I told you there was a decreased risk among women who took oestrogen alone. And if you graph the risk of oestrogen alone on the same graph as the combination, it is the identical curve. And yet oestrogen reportedly is associated with the decreased risk. And the combination increases the risk. There is no increased risk. It’s just that the placebo group against which the WHI investigators compared the women taking the combination had a lower than expected risk. Why should the placebo group have a lower than expected risk? Well, a significant number of them had been taking oestrogen before joining the study and being randomised to placebo. And if that population were removed from the data before graphing it, the increased risk completely disappeared. [00:18:16][352.7]

Dr Louise Newson: [00:18:18] Which is quite something, isn’t it? [00:18:20][1.5]

Dr Avrum Bluming: [00:18:20] I mean, more than something it’s actually very upsetting. It is not intellectually straightforward. And we rely on reports that help determine how we practice. And it is very upsetting when such an influential study continues to misquote their own data. [00:18:43][23.0]

Dr Louise Newson: [00:18:45] Now, there’s so many things that are wrong because it’s the same with us in the MHRA. Again, have this similar black box where it’s warning about oestrogen and in fact, cancer research over here, Cancer Research UK, say that significant number of breast cancers could be avoided if women did not take HRT. And when I’ve challenged them and I have on several emails, they’ve said yes, for oestrogen causes cancer. And again, I think about this alien thing. So if oestrogen caused cancer and I didn’t know any science and I didn’t know about the WHI, surely we would then be seeing a lot more cancer in younger women who produce naturally oestrogen, but also women who had more pregnancies. Because when we’re pregnant, we have very high levels of oestradiol in our bloodstream and there isn’t any evidence. In fact it’s to the opposite, isn’t it Avrum, for people who are pregnant? [00:19:40][54.8]

Dr Avrum Bluming: [00:19:40] That’s correct. The biggest risk factor for breast cancer, aside from gender, is age and the risk of breast cancer increases as age increases. And as you correctly state, we would think it should fall as oestrogen levels fall, and it doesn’t. In addition, we used to use oestrogen to treat breast cancer when we didn’t have chemotherapy or other agents. And there was a reported 44% response rates to giving oestrogen to women who have measurable breast cancer. And finally, a woman who is pregnant and gives birth before age 20 has a 70% reduced risk of lifetime development of breast cancer. There is a very interesting study that was just published by Ann Partridge this year from Harvard, saying that women who were taking a medication that is meant to interfere with oestrogen’s actions who were premenopausal and wanted to get pregnant, were allowed to take two years off from their treatment, get pregnant, which bathes the body in oestrogen and progesterone, and then come back to treatment. And they’ve been followed so far for seven years with no increased risk of recurrence. So clearly saying that oestrogen increases the risk of breast cancer is both wrong and not provable and harmful. One other thing. Progesterone deficiency is associated with a five times increased risk of breast cancer development. So blaming it on progesterone doesn’t make sense, especially since progesterone was also used to treat measurable breast cancer and was at least as successful as Tamoxifen. [00:21:47][127.0]

Dr Louise Newson: [00:21:48] Indeed. And so the other alien bit of me is thinking when the WHI came out, breast cancer incidence was probably about one in 11, one in 12 people, depending on what study you read. But people who, and we get a lot of letters of complaint in our clinic saying, how dare you put these women at risk of breast cancer by giving them HRT? And obviously we aren’t because we know the evidence. But if you were saying, as you did quite rightly, the prescribing rates for HRT in the U.S. were a lot higher, about 44% dropped to 5%. In the U.K., they were about 30% and they dropped to less than 10%. So you’ve got far less women taking HRT. So if you are saying, well, maybe it’s because it’s not the pure oestrogen, it’s HRT, because those three letters scare so many people. Surely with the reduction in prescribing of HRT, we will have had a reduction in incidence of breast cancer over the 20 years. So have we, Avrum? [00:22:55][66.4]

Dr Avrum Bluming: [00:22:56] Well, it depends on whom you ask. The Women’s Health Initiative investigators who still claim that oestrogen increases the risk of breast cancer do claim that there is a reduction in incidence as a result of the reduction in the frequency of hormone replacement therapy. There was a reduction in incidence of breast cancer in the US, which was noted starting in 1999, but which the investigators claim was really due to their 2002 publication. That doesn’t make sense. The reduction, they say, is still ongoing, but it’s not. The incidence of breast cancer around the world is increasing. And by the way, even that small reduction and it was small, was not seen in most countries around the world where hormone replacement therapy prescriptions dropped. And what’s most important to remember is the overwhelming majority of patients who take HRT do not develop breast cancer, and the overwhelming majority of breast cancer patients never took HRT. So to look at any population statistic and try to derive from that evidence of oestrogen’s carcinogenicity is misleading at best and dishonest at worst. [00:24:34][98.0]

Dr Louise Newson: [00:24:35] Absolutely. And certainly in the UK it’s around one in seven women who now develop breast cancer. And as you know, obesity has overtaken smoking as the commonest cause for all types of cancer, including breast cancer. So it’s not as easy as oestrogen causes breast cancer. And a lot of people are still told when they have an oestrogen receptor positive breast cancer, it’s an oestrogen driven or oestrogen caused. And actually, when I explain to women that not having a receptor is the abnormal bit, so when it’s oestrogen receptor negative, that means that the cancer’s mutated and is not actually as good prognosis often. We have oestrogen receptors, we’ve already said, everywhere. And so it’s not as easy and straightforward as just saying oestrogen causes breast cancer because there’s the alien bit of me that I keep talking about, which is a common sense bit, but there’s also the science bit and now we’ve got evidence as well. And what’s so sad for me is to know that an evidence-based approach has not been taken when it comes to oestrogen in HRT for women who’ve had breast cancer. And this study that has been really looked at by so many people and the majority people are in complete agreement with you, Avrum, it’s still the biggest barrier for women to be able to get HRT. And the other thing that I think is really sad is that choice is not being allowed. Now, you’ve already said women we know are scared about breast cancer, but actually when they know the facts, they are then more educated to think about how scary other conditions are. And so if I told you I had breast cancer or if I told you I’d just had an osteoporotic hip fracture, I think with all your knowledge and experience, you would be more concerned about my osteoporotic hip fracture because my outlook from that actually is more severe than most types of breast cancer. But it’s something about this word cancer. So we need to be thinking not also just about supposed risks of HRT that we’ve already said aren’t really there. We need to focus on the benefits because there are so many benefits from taking HRT for many, many women, aren’t there? [00:26:51][136.9]

Dr Avrum Bluming: [00:26:52] Yes, there are. And we have to be careful that we don’t dance around the question that most women ask, which is if oestrogen doesn’t cause breast cancer, why is breast cancer 100 times more frequent among women than it is among men? If oestrogen doesn’t cause breast cancer, why do treatments that we say impede oestrogen function seem to work on breast cancer? And the short answer is I can’t put it all together in a unified theory. I wish I could, but I can’t. I can avoid simplistic answers, however, and you had mentioned that an oestrogen receptor positive breast cancer often responds to some treatment that seems to interfere with oestrogen function. That’s true. Tamoxifen is the first drug that came on the scene for that. Tamoxifen has at least ten different functions besides oestrogen blockade. When Tamoxifen is given to a premenopausal woman, her level of circulating oestrogen goes up tenfold, and that doesn’t impair the therapeutic benefit of Tamoxifen. And by the way, the multiplying cells in a breast cancer that is responsible for the tumour growing is not an oestrogen receptor positive cell. Even among oestrogen receptor positive tumour patients, the oestrogen receptor is present on many cells in the body. You started the program off by saying that, and in oestrogen receptor positive breast cancer is a relatively slow growing breast cancer compared to an oestrogen receptor negative breast cancer. [00:28:55][123.1]

Dr Louise Newson: [00:28:57] It’s very interesting, isn’t it, yet women across the world, but actually also healthcare professionals across the world are still scared away from oestrogen. And it is really sad and I don’t quite know how that’s going to change. In fact, I’ve posted today, the day that I’m recording the podcast, not the day it’s going out, a little excerpt from your wonderful paper on my Instagram, and I only did it a few hours ago and already there’s lots and lots of interest. And actually the women are understanding and I think that’s what we work for, isn’t it? As doctors, we’re there, I remember you saying to me years ago, Louise, I’m an advocate for my patients. I’m here to listen and guide them. And I think that’s so important. But what we are realising with the work that we’re both doing in different ways in different countries is allowing women to have the knowledge and share, you know, what this sort of truth behind oestrogen as well, because it is quite easy when you know the facts. But there is so much good news about oestrogen. And so for you to write this article, I think is a real turning point. But it’s a shame it’s taking so long, isn’t it, for people to really understand? [00:30:19][81.8]

Dr Avrum Bluming: [00:30:20] It’s very important for women to understand. I was a practicing oncologist when the standard treatment for breast cancer was mastectomy, even a radical mastectomy, and it was thought for close to 100 years that breast cancer spread contiguously from one part of the body to tissue right next to it. And so you took off as much as you could, and that’s what doctors did. The reason it changed, even though we knew that a lumpectomy with radiotherapy was as good as a mastectomy as early as 1929, the reason it changed in the 1960s and early 1970s is because women got educated and said to their physicians, enough. They said, I’m not going to sign a consent form that allows you to remove my breast before I even know if I have breast cancer. You wake me up and we will talk about it. And women have to do the same thing here. A physician who dismisses you, if you ask about hormones, saying, I don’t want to kill you or I don’t want to give you poison, is not an informed physician, and your responsibility is either to help that physician find the appropriate information or you find a different physician. [00:31:52][92.7]

Dr Louise Newson: [00:31:53] Indeed, that’s such an amazing way to end. And I all for being the biggest supporter of my own future health, as well as a menopausal women myself who has been a patient to many different people before I received the treatment that I wanted. It’s really important that we have choice and that is so key. So I’m very grateful for your time, Avrum. And I hope people will listen to this podcast more than once because there’s a lot of information in there, there is a lot to unpick. So please take your time listening and hopefully share it with people, listen again in a calm way and you probably won’t be calm at the end because it’s very frustrating what’s been happening to women. But we can change it and we are changing things. So before I end Avrum, I always ask for three take home tips. So I’m very keen to ask you three things that you think will make the biggest difference over the next 20 years for women to get back onto hormones. What are the three things that you think are already helping or which will help more? [00:33:00][66.2]

Dr Avrum Bluming: [00:33:01] I think the single most important thing is for women to take an active role in their care. Now, we’re not pushing medicine, and this isn’t candy, like any medicine. Benefits versus risks. And we haven’t gone over the risks which are small, but they’re there, have to be calculated. But Eric Winer, who is the recent past president of the American Society of Clinical Oncology, in his presidential address, titled Partnering with Patients, saying that advancement of research and clinical care will be maximised if we partner with patients. Let them understand what we are suggesting and let them be active partners. I think that dwarfs anything else that would happen. I think the second step, and one that I would love to see but may not happen soon enough, is I’d love to understand what cancer is. Our current understanding of cancer as something that has to be cut out or burned out or poisoned out is a very simplistic understanding that doesn’t fit the experimental data that we already have. And once we understand it, we will be so much better off in being able to approach it intelligently. [00:34:36][95.6]

Dr Louise Newson: [00:34:38] Hmm. [00:34:38][0.0]

Dr Avrum Bluming: [00:34:39] That’s two. Offhand, I didn’t come prepared to discuss three, but of those two would be enough. [00:34:47][7.8]

Dr Louise Newson: [00:34:47] Oh I’m pleased you’re not greedy. Very good. I think. I think number three is keeping education for all healthcare professionals, actually, to allowing them a bit of time to really look at the evidence unpicked rather than just taking this top line that they’ve done for many years. And it is happening. Things are changing, definitely. So keeping professional curiosity not just for oestrogen, but for all aspects of medicine, I think is really important. [00:35:15][28.2]

Dr Avrum Bluming: [00:35:16] Being able to practice medicine, as you well know, is a wonderful privilege and very exciting. But in order to feel both privileged and excited, you must stay curious, recognise how little we know, and how much more we have to learn. [00:35:35][18.1]

Dr Louise Newson: [00:35:35] Absolutely. So thank you so much for your time today, Avrum. I really enjoyed it. [00:35:39][3.8]

Dr Louise Newson: [00:35:44] You can find out more about Newson Health Group by visiting And you can download the free Balance app on the App Store or Google Play. [00:35:44][0.0]


Getting to the truth around HRT and breast cancer with Dr Avrum Bluming

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