More cancers are being detected by screening, particularly among older women. A radiographer looks at mammogram results.
Although more and more women are surviving, breast cancer is the most common cancer in the UK and it has been on the rise for several years.
In 1999, 42,400 women were diagnosed with the disease. The odds that a woman would develop breast cancer during her lifetime were one in nine.
In 2008, 47,700 women were diagnosed. Taking into account the changing size of the population, this is an increase of around 3.5 per cent in the breast cancer incidence rate. As a result, we’ve calculated that the lifetime risk of developing the disease is 1 in 8.
This increase raises the obvious question: why have rates gone up?
Unfortunately there’s no simple answer to this. Breast cancer is a complicated disease with a variety of different causes. Many aspects of our lives swing our risk in one direction or another. Some of these can be controlled, while others are largely out of our hands.
Let’s take a look at some of the possible explanations.
Screening
In recent years, breast cancer rates have risen especially quickly among women aged 65-69. This probably coincides with the inclusion, from 2004, of women in this age group in the national breast screening programme. An increase in the number of women attending screening would be very likely to lead to an increased number of cancers being detected.
In many ways, this is to be expected. Screening programmes are meant to detect cancers at an early stage when they’re too small to cause any symptoms. At this point, they are easier to treat successfully. So you would expect rates to go up when a new group of women is invited for screening.
The screening programme has attracted a lot of recent controversy. Critics say that it picks up a large number of cancers that would never go on to cause a woman any problems. These include a type of cancer called ductal carcinoma in situ (DCIS) – a ‘pre-cancerous’ type of tumour that has not yet started to spread. But our new analysis doesn’t include cases of DCIS, so these non-invasive tumours can’t explain the rising breast cancer rates in women aged 65-69.
Lifestyle
Several aspects of our daily lives can affect the risk of breast cancer. We know that alcohol can cause breast cancer, and even drinking small amounts can increase the risk of this disease. Alcohol boosts levels of oestrogen in the blood, and abnormally high levels of this hormone have been linked to breast cancer.
Large studies have found that drinking an extra unit every day (and remember there are two units in a medium-sized glass of wine) can increase the risk of breast cancer by around 10 per cent. That’s not a big effect, but because the disease is so common, it translates to a surprising number of extra breast cancer cases. For example, the Million Women Study estimated that if everyone drank one extra unit a day, we would see 11 extra breast cancers in every thousand women. The study calculated that 11per cent of breast cancers in the UK are caused by alcohol.
After the menopause, women who are overweight or obese have a higher breast cancer risk than those who have a healthy weight. The Million Women Study also looked at body weight, and calculated that obesity accounts for 7 per cent of the UK’s breast cancer cases. The nation’s expanding waistline could be contributing to the rise in breast cancer rates.
Body fat is surprisingly active, pumping out oestrogen and other hormones that affect how our cells grow and divide. This source of oestrogen becomes increasingly important after the menopause when the ovaries stop producing the hormone.
On the flipside, keeping physically active could reduce the risk of breast cancer by anywhere from 20 to 40 per cent. Researchers are still trying to find out exactly what causes this effect, but again, the evidence points to our hormones.
HRT
We know that hormone replacement therapy can increase the risk of breast cancer although it’s not clear how much this accounts for the recent trends.
The use of HRT rose sharply in the UK between 1992 and 2001. At that point, around a quarter of women aged 45-69 were using HRT. However, the medication’s popularity soon plummeted as it became clear that it was linked to breast cancer.
We know that the longer a woman takes HRT, the higher her risk of breast cancer becomes, and it takes around 5 years for that risk to return back to normal after stopping. So the recent climbing rates could partially reflect the aftermath of prolonged HRT use.
Children
People often forget this when talking about breast cancer, but having children protects against the disease. Women are less likely to develop breast cancer if they have their first child at an earlier age. Their risk also goes down the more children they have and the longer they spend breastfeeding.
These simple associations can explain a lot of the differences in breast cancer rates between developed and developing countries. One study calculated that if women in the Western world had the same number of children as women in the developing world (and breastfed as long), the rates of breast cancer would halve.
Age
People are living longer now than ever before. And one of the risks for most cancers is simply getting older. But it should be noted that the 1 in 8 figure is a lifetime risk – and that during a lifetime, risk changes. For breast cancer, risk increases sharply from around the time of the menopause – see the table below:
| Up to and including age | Risk (women) |
| 29 | 1 in 2000 |
| 39 | 1 in 215 |
| 49 | 1 in 50 |
| 59 | 1 in 22 |
| 69 | 1 in 13 |
| Lifetime risk | 1 in 8 |
Other possible explanations
There are many other potential causes of breast cancer – some are myths, others have some truth to them. We’re only going to touch on some of them briefly here, but you can click through for more information.
The Pill probably hasn’t had a big effect on breast cancer rates. It only slightly increases the risk of breast cancer. Women take it at a young age when their natural risk is low, and that risk disappears quickly when women go off the Pill.
Our diet can affect our risk of cancer. But despite hundreds of studies and countless books or magazine articles, there’s no clear advice for eating your way to a lower breast cancer risk (other than cutting back on alcohol and keeping a healthy body weight). Studies have looked at everything from fruit and vegetables to dairy products and they have either refuted a link to breast cancer, or found inconsistent results.
Working on night-shifts could affect the risk of breast cancer, according to the International Agency for Research into Cancer. Many scientists are now trying to work out if this is actually true. The problem is that few of the studies to date have accounted for other things that can affect breast cancer risk, like number of children or body weight.
Vitamin D is a hot topic but despite repeated claims, the evidence linking it to breast cancer is uncertain. Recently, several groups have gathered all the available evidence and when they considered the best studies, they found no link between vitamin D and breast cancer.
Deodorants were originally linked to breast cancer in an email hoax, and there’s no convincing evidence that they could cause the disease. Nor is there solid evidence for other types of cosmetic products.
Stress can alter the levels of hormones in the body and affect the immune system. But there’s no consistent evidence that these changes could lead to breast cancer. However, stressful situations can make people take up unhealthy behaviours such as smoking, heavy drinking or overeating that can themselves increase the risk of cancer.
Chemicals in our environment probably don’t play a significant role. There’s been a lot of controversy over the role of man-made chemicals that can mimic oestrogen and, theoretically, cause breast cancer. This is an active area of research and debate, but at the moment there’s not enough evidence from studies in humans to suggest that these chemicals play a significant role in increasing rates of breast cancer.
Large organisations like the World Health Organisation (WHO) and the International Agency for Research into Cancer (IARC) have estimated that pollution and chemicals in our environment only account for about 3 per cent of all cancers. Most of these cases are in people who work in certain industries and are exposed to high levels of chemicals in their jobs.
The good news
While it’s worrying that women are now more likely to develop breast cancer than they were a decade ago, there is good news too.
Survival rates have also shot up. Figures released in 2019 revealed that the number of people dying from breast cancer has fallen by 44% compared with 30 years ago, when breast cancer death rates were at their highest. That’s the equivalent of over 130,000 deaths avoided, thanks to improvements in treatment and diagnosis.
And more than three-quarters of women diagnosed with breast cancer survive for at least 10 years or more. Research has been at the heart of this progress – and it will continue to play a vital role in beating the disease in the future.
Henry
Further reading
- Information for people affected by breast cancer
- Breast cancer statistics for professionals
- What do we mean by ‘risk’?
- Our current breast cancer research
- Help support breast cancer research on MyProjects
- Our impact on breast cancer
- Other ways to get involved
Comments
Wendy Green February 6, 2011
Like Irene, I had Grade 3 BC 3 years ago and would be interested to understand the survival rate for me – not the average across the board. Incidentally, I have never drunk much alcohol, never smoked, always been good weight (except since my illness) been fit and healthy but did have hrt for 5 years. No history of any cancers in family.
Ben Samuel February 6, 2011
Sorry to be a Green troll but, Cancer Research UK have not even mentioned radiation from nuclear fallout, waste etc.. Are we to believe that there is “not enough evidence”.
Helen February 5, 2011
I would be interested to know if there is any link between living under electricity pylons during childhood and breast cancer. I lived directly under pylons until age 20. I was diagnosed with an aggressive grade 3 tumour at age 40 and then another unrelated(in the other breast)two years later. My next door neighbour had breast cancer , as did another nearby neighbour,at the same age as me,- both sadly died.This seems a huge coinsidence to me!
J Doherty February 5, 2011
Thank you Margaret Chappell for your helpful response and the link to the useful BBC article.
However, if “not all the “cancers” diagnosed through screening would ever have caused symptoms” then surely screening must cause an increase in breast cancer diagnoses.
JD
kay Light February 5, 2011
I think it comes as no surprise, nearly everyone of my age seems to be on HRT. (59) Also with all the conflicting advice that constantly comes out about what to eat what not to eat and breastfeeding the nation is confused. Genetics surely play a major part, but manufacturers of HRT and other drugs must surely be another major factor in this rise.
Jules February 5, 2011
I have a personal theory about the sudden rise in breast cancer. Many years ago poultry farmers were known to inject the poultry with hormones. To do what? to make the breasts larger as that is the part that sells. I know several dear people that have died from breast cancer and in each case I either asked or knew that they ate a lot of chicken in their weekly diet as it is less fatty. These ladies were very fit, very diet conscious and ate mostly organic food, but did buy their chicken from supermarkets where the source was mass produced. It will be interesting to see if the levels of breast cancer come to a point of decreasing as the time lapse of hormone injections decreases. I do hope that some research is done on my theory! – I may be completely wrong but it does seem to fit. I am sure there are many other factors too but I wouldn’t be surprised if this theory is a valid one.
Nicola February 5, 2011
RE Breastfeeding reducing risk of breast cancer
I read that breastfeeding reduces the risk of breast cancer because most women have few, if any, menstrual cylces (same applies for pregnancy) whilst (exclusively) breastfeeding.
But what if a woman has regular periods (despite exclusively breastfeeding) from the day the babies were born. Will the, say, 6 years of breastfeeding have any risk reducing effect in this case?
Would love to know you opinion on this!
Amette Ley February 5, 2011
You haven’t mentioned the link shown in several studies between the non-spontaneous abortion of a first child, resulting in high oestrogen levels without a pregnancy to support. [This is not usually linked to spontaneous abortion (miscarriage) as the hormone level would have gradually decreased beforehand.]
Ingrid February 4, 2011
I have a healthy diet, regular exercise, drink very rarely and have no family history of breast cancer, however, at the age of 23 I got diagnosed with breast cancer. It might be rare in my case, however, there are no statistic to support the under 29 year old woman that get diagnosed with breast cancer.
I found my lump in August 2010, after seeing consultation from three different GPs I was then referred for tests on the lump. In December 2010 I got diagnosed with breast cancer and can now finally get the right treatment.
With the time it took for me to be diagnosed, I now have to go through a longer more rigorous treatment. If I had been older I feel that it would have been dealt with quickly and more seriously.
I just want to make women aware of the fact that being young, healthy and fit does not mean that you are exempt from this awful disease.
susie. February 4, 2011
I would just like to reassure some of the women that have contributed, that there are other women on study progammes into the courses of breast cancer.One study is about weight,alcohol,genes,lifestyle.Hopefully some results made be out in the spring. There is also the million women study which was mention in an email, This is still ongoing. I was also her2pos’ and have given regular blood samples to continue with the research. They are always looking for people to join study progammes when funds allow. The more that join in the better the research.
Isabel February 4, 2011
Yes, radioactivity is of HUGE interest to me. My son was diagnosed with thyroid cancer in 2001. He was 12. He is now 22 and thriving. But, the BC i had 3 years later could be due to the massive stress, IF stress were a risk factor, which it isnt…. apparently….We dont live near any known radioactive hot spots here in Dorset. Apart from the EDF plant across the sea in Normandy.
M Wright February 4, 2011
Have any studies been conducted on the possibilty that when the UK was covered in radioactive fallout following Chernobel that all cancers have been on the rise?
Isabel February 4, 2011
I had BC (grade 2 DCIS that had spread a bit and 1 affected lymph node) in 2004, I was 44. I had double mastectomy(from choice) and chemo. BUT i had none of the risk factors: I had 3 babies before the age of 33, and breast fed them all, i hardly drank a drop of alcohol then, and none now. I love healthy food, but was always between 8 1/2 and 9 1/2 stone prior to diagnosis. I have never ever smoked any type of ‘tobacco’. But would have been a passive smoker as a child. Your article doesn’t mention smoking at all. Why is this? Are we really 100% sure that nicotine/cannabis and other narcotics have no part to play in causing healthy breast cells to turn cancerous?
I would love to know!!!!
Rose Kenny February 4, 2011
Could anyone tell me if at 51 you should have a breat screening, if you do not have any symptons
Irene North February 4, 2011
I had a grade 3 aggressive breast cancer two years ago. Is the increased survival rate applicable to the more severe tumours that required chemotherapy?
Kevan Gelling February 4, 2011
they found no link between vitamin D and breast cancer
Both meta-analyses found that, in the case-control studies, higher vitamin D levels reduced breast cancer incidence (by 17% and 41% respectively). There were unable to say that the results were conclusive, but they found a link. The 2nd meta-analysis concluded that “further studies are needed”.
A randomised control trial in 2007 found that vitamin D supplementation reduced breast cancer by 37%.
A new 10 year study (E3N cohort – PMID 21127286) suggested that “vitamin D exposure from both sun and diet is required to prevent [breast cancer]”. Another (PMID 21160130) concluded “vitamin D had a protective effect against breast cancer in premenopausal women of normal weight in subtropical Taiwan”
Breast cancer is more common at higher latitudes, women with breast cancer have lower levels of vitamin D, in the lab vitamin D has been shown to inhibit breast cancer cells, etc.
The evidence may be uncertain, but there definitely is a link.
Cherub February 4, 2011
For years I’ve been reading about the link between alcohol and breast cancer, but what I’d really like to see is some decent research into what causes the over expression of growth hormone leading to a diagnosis of Her2 positive cancer. I was diagnosed with this 4 years ago and feel a lot more research is needed.
Harold Hobbs February 4, 2011
Breast cancer is increasing because all cancers are increasing. The reason for this is our increasingly toxic chemical filled environment.
m adams February 4, 2011
What is the rate of breast cancer among alcoholics? Do male alcoholics get breast cancer?
Margaret Chappell February 4, 2011
@ J Doherty. Cancer Research UK hase not included breast screening itself as a cause of the increase in diagnoses of breast cancer. Note that I used the word diagnoses – not all the “cancers” diagnosed through screening would ever have caused symptoms during life (due to low risk of growth and spread and death from other causes before significant tumour growth). There are also difficulties in the way statistical findings are presented. See this interesting article on the BBC News Magazine.
http://news.bbc.co.uk/1/hi/magazine/7910011.stm
Sorry link not worked and you will have to cut and paste the address.
Diagnosis of tumours without serious malignant potential could also have contributed to the apparent increase in survival, as women are included who would not have died even if left untreated. The increase in survivial is undoubtedly related to better treatment but this unfortunately has side-effects which are sometimes dangerous as well as unpleasant. All to be considered in the complicated business of figuring out quite how helpful screening is.
Lisa February 4, 2011
I think more women should hear the message that breastfeeding for the recommended period of time can reduce breast cancer risks. Many women are simply unaware. Also – it seems to have been found that their daughter’s risk (of breast cancer) is reduced!
Made my day this morning to hear Dr Kat Arney including lengthy breastfeeding in a discussion of how a few simple steps can markedly reduce the risk of breast cancer… and then to hear it all over again a few minutes later on the news on R4 Today.
Thankyou!
J Doherty February 4, 2011
Dear Editor,
Re Screening.
Excluding DCIS, what is the estimated contribution of screening overdiagnosis to the increase in the 65-69 group?
Thanks,
JD
Jules610 February 4, 2011
Could you please let me know how these findings relate to breast cancer patients or future patients that are “triple negative”? There seem to be little (published) reports in the UK about this section of suffers who, I believe, are a not insignifacant section of those diagnosed. Although obesity and alcohol are not good things, I feel that people should be aware of other factors.
Gesa Behrens February 6, 2011
It has been proven that women taking estrogens for osteoporosis prophylaxes do have a much higher risk of getting breast cancer. How can it be, that younger women, taking exactly the same hormons (estrogen and gestagen) in form of the pill, do not have an increased risk?????? This is not plausible. Furthermore, the increase of breast cancer in the recent years fits well to the time, that the pill has been introduced in the 70s. As the pharma industry would have huge disadvantages of this risk being proven, of course there is no research about this. But clearly thinking, this has to be one of, if not THAT major risk for breast cancer. Regards from Gesa, medical student from Germany.