Much of the UK media are covering the release of data that indicates breast cancer rates in the under-50s are now at a record high. Changes in childbirth patterns and alcohol consumption could be to blame, according to a leading charity.
The news follows new data released by Cancer Research UK. Its data shows that breast cancer diagnoses among women aged under 50 have now reached an all-time high, breaking the 10,000 mark for the first time in 2010. One in five diagnosed breast cancer cases are now in women under the age of 50.
Possible explanations for the increases are speculated to be due to known hormonal risk factors for cancer – such as having children later in life. Increased alcohol intake, another risk factor for breast cancer, could also be involved.
The rise in the number of new cases is not restricted to the under-50s: there has been a steady increase in the number of cases diagnosed for women of all ages since the 1970s.
But the rise isn’t necessarily as bad as it sounds. For example it could reflect better breast awareness and improved diagnosis and screening, which in turn might lead to early treatment and improved chances of survival.
The good news is that – despite the increase in breast cancer diagnoses – breast cancer deaths are actually falling. An increasing number of women are now survivors of breast cancer.
What does the data show?
Breast cancer is the most common cancer among women, accounting for almost a third of all new cancer cases in women. Cancer Research UK reports how their latest statistics revealed that in 2010, there were 10,000 new cases diagnosed among women aged under 50. This is an 11% increase from 15 years previously in 1995 when there were 7,700 cases of breast cancer diagnosed among women in this age group.
One in five breast cancers (20%) are now diagnosed in women aged under 50. Nearly half of breast cancers (48%) are diagnosed in women aged between 50 and 69 – the age group currently invited for breast cancer screening.
However, the rise in the number of breast cancer cases is not restricted to the under-50s. Since the 1970s there has been a gradual and steady increase in the number of breast cancer cases. Overall there was an 18% increase in rates between 1995 and 2010.
What are the possible reasons behind the increased rates among younger women?
Cancer Research UK says that, though it is not clear why cases of breast cancer are increasing among younger women, alcohol intake and hormonal factors may play a role.
Alcohol is an established risk factor for breast cancer. Cancer Research UK reports that the combined results of two large systematic reviews of the published evidence, in addition to findings from the UK Million Women Study, suggest that each additional unit of alcohol per day can increase a woman’s risk of the disease by between 7% and 12%. The research suggests that by the age of 80, roughly the following number of women will have developed breast cancer:
- 9 out of 100 if they don't drink at all
- 10 out of 100 if they have two drinks a day
- 13 out of 100 if they have six drinks a day
However, as Cancer Research UK does say, the possible risk increase from alcohol is less compared to the greater influence of other factors – particularly hormonal factors.
Very generally, increased exposure to the hormone oestrogen is associated with increased risk of breast cancer because it can stimulate breast cancer cells to grow. Higher lifetime oestrogen exposure is associated with:
- starting periods at a younger age
- going through the menopause at a later age
- use of the combined oral contraceptive pill (which contains oestrogen)
- fewer (or no) pregnancies
- shorter duration of (or no) breastfeeding
- use of HRT (which contains oestrogen)
Both having children and breastfeeding are known to be protective against breast cancer. In theory the younger a woman is when she has her first pregnancy, and the more pregnancies she has in her lifetime, further decreases her risk. Similarly, the more a woman breastfeeds will decrease her risk. Therefore, modern western lifestyles (that include women generally starting families later and having smaller families) may give some possible explanation to the increase in breast cancer rates among younger women.
Are there any positive signs?
Despite the increased rates among women overall and specifically among women aged under 50, Cancer Research UK does report some good news: that fewer women than ever before are now dying from breast cancer. This due to better treatment, the charity says.
The rate of women aged under 50 who are dying from breast cancer has fallen by 40% since the early 1990s. Twenty years ago, the death rate from breast cancer in the under-50s was 9 per 100,000 women in the UK. By late 2000, this had fallen to 5 per 100,000 women. More than 8 in 10 women diagnosed with breast cancer before the age of 50 are now reported to survive the disease for at least five years.
Although not discussed by the Cancer Research UK report, the rise in cases could be a reflection of increased awareness of breast cancer and increased rates of diagnosis and improvement in screening techniques.
As a concluding message, Sara Hiom, Cancer Research UK’s director of health information, says: “Breast cancer is more common in older women, but these figures show that younger women are also at risk of developing the disease. Women of all ages who notice anything different about their breasts, including changes in size, shape or feel; a lump or thickening; nipple discharge or rash; dimpling, puckering or redness of the skin, should see their GP straight away, even if they have attended breast cancer screening.
“It’s more likely not to be cancer, but if it is, detecting it early gives the best chance of successful treatment,” she added.
What can I do to reduce my risk of breast cancer?
Unlike some other cancers, the body of evidence about proven methods of reducing risk is relatively small. Though most experts would recommend that:
- you stick to the recommended alcohol consumption rates for women
- you take plenty of exercise
- you maintain a healthy weight
- avoid smoking
It is also important that you attend breast cancer screening appointments when invited. Women aged 50 to 70, who are registered with a GP, are automatically invited for screening every three years.
Read more about the NHS Breast Screening Programme.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
The Guardian, 3 May 2013
Daily Mail, 3 May 2013
The Daily Telegraph, 3 May 2013
Daily Mirror, 3 May 2013
Links to the science
May 3 2013