Breast Cancer in women
Ideas about causes of breast cancer
The causes of breast cancer are not yet completely understood, but certain women do seem to be at a slightly higher risk of developing the disease.
The risk of developing breast cancer is smaller in women under the age of 25 and increases as women get older. Occurrences rise steadily from age 25-29 and develop more steeply from age 35-39 (Cancer Research UK, 2017-2019 data). Eight out of ten (80%) breast cancers occur in women over the age of 50 (Macmillan Cancer Support 2023).
Other risk factors include:
- having a significant family history of breast cancer
- lifestyle factors such as being overweight, alcohol consumption, and smoking
- using hormone replacement therapy or taking the contraceptive pill
- history of previous cancer treatments such as radiotherapy
- having had breast cancer or some other breast conditions before
Personal ideas about causes of breast cancer
Here, women discuss their ideas about the causes of breast cancer.
Many women said that, although they were aware that the causes of breast cancer were not yet fully known, they often wondered how or why they’d got it, sometimes asking themselves the question 'why me?'
Genetic risk factors
Some women who had relatives with breast cancer felt that genetic factors were an important cause. Other women pointed out that the genetic component was small.
Less than 10% of breast cancers are thought to be related to a hereditary mutation in genetics (Macmillan Cancer Support, October 2023). The two main genes linked to breast cancer are BRCA1 and BRCA2, but there is increasing research into the connection of genetic faults and the possible increased risk of developing breast cancer. The following genetic faults have been evidenced to contribute to an increased risk of developing breast cancer:
- Li-Fraumeni syndrome caused by a fault in the TP53 gene
- MUTYH associated polyposis (MAP) caused by faults in the MUTYH gene with 1 faulty copy of the MUTYH gene from each parent
- Faults in the PALB2 gene
- Peutz Jeghers syndrome (PJS) caused by a fault in the STK11 gene
- PTEN Hamartoma tumour syndrome and Cowden syndrome caused by a fault in the PTEN gene
Cancer Research UK provides more information for genes that show an increased risk for developing breast cancer.
Experiences of diagnosis related to genetics
Tess, who was diagnosed with breast cancer at the age of 33, had tests to see if she had the BRCA1 and BRCA2 genes.
Comments on the increased risk of developing breast cancer if other family members have had it.
Comments on the increased risk of developing breast cancer if other family members have had it.
I have talked to the genetics department about whether in fact my daughter and my sister's two daughters are sort of, may well get breast tumours, and both of my sister and myself it was post-menopausal, so it wasn't, it wasn't sort of earlier than that.
But evidently last, the year previously to when I spoke to them, they said that if there had been 3 members in the family that had had a breast tumour then they would've deemed us to be an at-risk category. But because of budget cuts they now had to increase it to four, which I thought was quite interesting (laughs).
So all I can do about the girls in the family is that they should be checked regularly and I think I'd probably tell the whole world that they should be, all the women in the world that I meet that' "Have you examined your breasts? Do make sure that you do. "I do on a regular basis. And go for breast screening when it comes along as well."
Tess had tests to find out if she had the BRCA1 and BRCA2 genes. It took a long time to get the results but the information was helpful.
Tess had tests to find out if she had the BRCA1 and BRCA2 genes. It took a long time to get the results but the information was helpful.
It wasn’t for me because I already had cancer, so I suppose I wasn’t really concerned for me. It was more for my younger sister. And I think it was very difficult for her waiting for these results and not knowing really what the implications were. And for my children.
But I think it’s helpful if, I suppose I felt all information was helpful. Because part of me almost didn’t want to get the tests but I suppose you sort of think well all information is helpful. And if it meant that my sister could then be tested and know kind of more clearly what she should have in terms of screening, then that was definitely worth it. But it wasn’t a nice kind of experience.
And for any women who are thinking about the having the tests? What did they, what did they involve?
It’s just a blood test. But I think to be prepared for how long it’s going to take. Because I mean it’s months to years where I had it done. Maybe it’s different, but it’s just worth checking how long and what actually the real implications of the result are. Because it’s not like the other tests you have, which are quite immediate and you can kind of find, you know, you’re sort of talking like days or weeks. And then you can make a decision based on that. It does take a lot longer, and it’s a lot, and the results are a lot less clear cut I think.
So from the start of the tests to when you actually found out, how long was the whole process?
From the BRCA1, it was over a year definitely. Maybe I got BRCA, I think maybe I got BRCA1 back within months, and then BRCA2 took about a year. I might have that wrong, but it was definitely over a year.
Hormone use as a risk factor
Many women suggested that a number of different factors might be involved in causing breast cancer. Some believed that a possible cause could be related to hormone use and discussed the contraceptive pill and Hormone Replacement Therapy.
Cancer Research UK (2024) cites that less than 1% of breast cancer cases in the UK are connected to oral contraceptives and 2% are related to Hormone Replacement Therapy (post-menopausal hormones).
Diet as a risk factor
Women also discussed the possibility of the connection between diet and cancer, and several said they’d made dietary changes following their illness. Some compared the Western lifestyle and diet with non-Western countries. Other women said that they did not know why they should have developed breast cancer, pointing out that they had always led a healthy lifestyle.
Discusses possible links between diet and cancer, and some of the dietary changes she made.
Discusses possible links between diet and cancer, and some of the dietary changes she made.
I have read about how foods are preserved and I don't like the sound of it at all. I don't like the fact that most of the meat that we're eating are fed drugs and hormones to make them healthy and fat.
And perfect robust looking fruit and vegetables have usually been artificially grown and they leave substances and things on the skin that can do all sorts of damage. Even eggs that we eat.
The poultry are fed stuff that dyes the yolk a bright yellow because that's what they think we want.
Organic dairy stuff but I don't overdo the dairy, but I take supplements.
And the real key, that I never did much of, was drink tons of water.
Water flushes toxics out of the system.
Comments on diet and the lower incidence of breast cancer in Japan.
Comments on diet and the lower incidence of breast cancer in Japan.
But I don't know that anyone has yet come up with anything that is really acceptable for breast cancer.
I think in other countries they don't have, for instance I believe in Japan there's a very low incidence of breast cancer. But they do have other cancers. So I think that's perhaps where there could be some link with diet but I don't know, there's nothing proven.
Other noted risk factors
Some women said that breast cancer seemed to strike randomly and that every woman was potentially at risk. Some of these women reported that they fitted into none of the risk factor categories. One of these women criticised media reports on the causes of breast cancer because they lacked evidence and caused panic. Stress as a possible cause of breast cancer was also discussed. A few women wondered about the impact of the environment, pollution and chemicals.
Comments that she fits into none of the risk factor categories and is critical about media reports on the causes of breast cancer.
Comments that she fits into none of the risk factor categories and is critical about media reports on the causes of breast cancer.
Having found the information, having read the Imperial Cancer Care Book on breast cancer, which I really do think is highly informative. And you look at the risk factors. I didn't fit into any of them.
So to me cancer is a nasty disease that can strike anyone.
And yes, there are things that people can do to help themselves, such as not smoking (I gave up 11 years ago or so), but you certainly do need to start to help yourself once you are a victim of cancer.
And to enable you to do that you need to have the correct information. You will find all sorts of things in the media which can be quite scare mongering, on hair dyes, on whether or not you breastfed, on whether or not you had terminations.
I'm not sure that any of these things are factual. I would strongly suggest to people that they disregard them completely. Don't allow things to frighten and scare you. Stick with the experts. Stick with what it is you know.
Ask the necessary questions if something, if you're overwhelmed by something, you think "that could be me" or perhaps, you know, "I shouldn't do that" or whatever.
And I mainly have time to do or I've made time to do the things that Ive wanted to do and that I've been putting on hold for years.
Explains why she believes that stress might be involved in causing breast cancer.
Explains why she believes that stress might be involved in causing breast cancer.
I've been very much more fortunate than many in that, but it's just tiring and other stresses of life probably all combine, and maybe I had more factors than I realised.
And at the moment we don't really know what they all are. I think it can only be beneficial to cut down on the stresses that you can really. Don't take on things you can't deal with.
I do know quite a lot of women who, in fact I would say nearly all the women I met in hospital, had had some sort of trauma or difficulty.
I mean most people have had traumas in their life by the time they get to their mid-life, but there was a surprising number who'd had difficulties of one sort and another and they'd ended up with breast cancer.
Or they'd had a very unhappy time in one way and another. And I just personally think that that must all be relevant but it's probably difficult to say why.
Wonders about links between breast cancer and chemicals.
Wonders about links between breast cancer and chemicals.
They say that there's something that they put on sugar beet which gives you cancer. I can't remember the name of it. But you know there are all these theories, not for eating it but for being with it. And when I was in Lincolnshire I went round a sugar beet factory and I was quite near the sugar beet.
But I think probably you have to be near it for perhaps ten years or so you know. But you sort of hear all these things and I do not know what gave me cancer. I don't smoke. I drink a little but they say that's good for you.
One woman emphasised the importance of more research into the causes of breast cancer and questioned the role of pharmaceutical companies. A few women said that age was an important factor and that most women with breast cancer were between 50 and 65. One woman wondered about the effects of x-rays, and another mentioned that an increase in breast cancer statistics might partly be a result of heightened awareness and better technology.
Raises the issue of further research into the causes of breast cancer and the interests of different groups.
Raises the issue of further research into the causes of breast cancer and the interests of different groups.
Causes and prevention - not nearly enough research is being done on those.
Causes, you know, don't tell me you know, smoking and genetics, I mean the genetic thing is only you know, eight to ten per cent susceptibility, it doesn't give you cancer. And I think it's monstrous that more research is not being done.
And one of the reasons is the research into the treatments are funded by pharmaceutical companies who can make a very large profit out of it. And they need to look at their ethics, they really need to look.
I just wonder how many people on the boards of directors have relatives or friends who've died from cancer. I mean that should tell them, you know for the next generation, we need to know. And so people can make choices about lifestyles as well.
And that is another thing that, it's not often you can get help in that; looking at nutrition; looking at exercise, you know; how we live in a vastly polluted environment now.
And there are organisations who are politically involved.
Suggests various reasons why the incidence of breast cancer appears to be increasing.
Suggests various reasons why the incidence of breast cancer appears to be increasing.
Today well we've got the better facilities for finding out.
People are more aware.
Also the fact, and I think this is a big factor, people are living a lot longer.
Also I wonder, they say not but I wonder, was it, is it sixties, seventies, they went mad with all these chemicals on the land.
Two women fell into several risk factor categories and said that this helped to explain their susceptibility.
Explains that she fitted into several risk factor categories.
Explains that she fitted into several risk factor categories.
Let's go back, family history' my sister died of breast cancer, I had a paternal aunt who did and my mother, we were never quite sure what she died of but it was certainty gynaecological cancer, ovarian possibly, but you know it was all a bit mysterious. So that's the family history.
I had my babies latish, my first baby was born when I was almost 29 which doesn't sound late today but believe me it's later than it should be.
I couldn't breast feed them, at least the first one I couldn't, because she was a little prem, and I couldn't get my hands on her in time.
And out of some misguided sense of what is better for, I wanted to treat all the children the same so I didn't breast feed the boys either.
I had thyrotoxicosis when I was a girl. I had my thyroid removed. And that for some unknown, I don't know the details of it, but that is a predisposing factor, a bit.
And I'd been on HRT for many, many, many years. I'd done that as a gamble. I knew perfectly that HRT does have a slightly, and I mean slightly, increased risk of breast cancer. But I also knew that it did protect more slightly again coronary thrombosis and cerebral haemorrhage. And I thought right I would, on balance, I would rather cope with breast cancer than cope with a stroke or a heart attack.
Last reviewed November 2024.
Last reviewed November 2024.
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