Breast cancer – why do the over-70s often fare worse?

Why do some older women with breast cancer fare worse?

A new study published in the British Journal of Cancer today sheds some light on why older women with breast cancer tend to fare more poorly than their younger counterparts.

Previous studies have told us that age affects the odds of surviving breast cancer. But until now scientists could only speculate as to why this might be.

This new research puts late diagnosis and treatment differences into the frame.

What did the scientists do?

The study led by Cancer Research UK scientist Professor Paul Pharoah examined hospital notes from more than14,000 women with breast cancer from the East of England.

The researchers were able to weigh up the effect of different variables on a patient’s chances of survival, including their age, wealth, the way their cancer was diagnosed, the size and aggressiveness of their tumour, the treatment they received and how advanced their tumour was when they were diagnosed (known as a tumour’s ‘stage’)

What did they find?

The researchers found that women in their 70 and 80s were less likely to survive breast cancer than women in their 50s and 60s. Older women were more likely to be diagnosed with more advanced cancers and were less likely to be treated with surgery or radiotherapy.

They also found that older women were less likely to have tests to find out their ‘oestrogen receptor status’ – which measures levels of a particular molecule in their cancer cells and can help determine the best treatment. Here are the key findings in detail:

• More than half (51 per cent) of women aged 50 to 69 had their breast cancer diagnosed at the earliest possible stage, compared with  only a quarter (26 per cent) of breast cancers in the over 80s.
• More than a third (35 per cent) of older women had unknown oestrogen receptor status, while amongst younger women only about one in 10 (11 per cent) had this information missing from their notes.
• 69 per cent of older women had missing data on whether cancer had spread to the lymph nodes compared with 14 per cent women aged 50 to 69.
• The chances of receiving surgery or radiotherapy decreased with age. 96 per cent of younger women had surgery compared to three-quarters (74 per cent) of 75 -79 year olds, and fewer than half (43 per cent) of women over 80.
• Three-quarters (74 per cent) of 50 – 69s year olds were given radiotherapy, while for the over 80s the figure was around a quarter (26 per cent).
• Of all the disease characteristics and treatment types studied, surgery had the greatest impact on breast cancer survival.

Why might this be and how important is it?

1) Stage at diagnosis

Stage at diagnosis is one of the most important predictors of cancer survival. When diagnosed at an early stage, cancer is easier to treat and people have better outcomes.

It is difficult to say why older women tend to have their breast cancers diagnosed at a late stage – Professor Pharaoh’s team didn’t look at that in detail. It might be that they’re less likely to attend screening, less aware of breast cancer in general, or more likely to delay reporting suspicious symptoms.

Breast screening is available to all women over the age of 50 in the UK. Up to age 70, women receive a routine invitation through the post. After that, women are eligible for screening but must request an appointment.

We know from previous research that many women assume that their breast cancer risk goes down after 70 because they aren’t automatically invited for screening. That’s not true – the risk of breast cancer still remains high.

2) Testing oestrogen receptor status and lymph node involvement

Testing a woman’s breast cancer cells for hormone receptor status, and examining her lymph nodes, helps doctors to decide which treatments will be most appropriate. It’s not known why older women are less likely to have their oestrogen receptor status or lymph node status recorded, but it really needs to be understood . The suggestion is that this age group may not always be receiving the best care.

3) Surgery and radiotherapy

Surgery and radiotherapy are two of the most effective methods of treating breast cancer. Doctors consider many things when deciding which treatments are best for a woman with breast cancer, including her general health, her preferences, and the type, size, stage and aggressiveness and receptor status of her tumour. Many of these things will vary according to age.  So it isn’t necessarily surprising that older women receive different treatments from younger ones.

But it isn’t clear whether these factors account for all the treatment differences seen in this study. We need to find this out.

What can we do to improve the outlook for older women?

It goes without saying that all women, regardless of their age, should be offered the best chance of having breast cancer diagnosed early and treated effectively. To achieve this, we have to ensure that women over 70 can readily get information about the continued risk of breast cancer, the importance of breast awareness, including eligibility for screening. And we must make sure the best possible treatments are available to all, irrespective of age.

All women, including the over 70s, should be encouraged to know what’s normal for them so that they have the best chance of noticing any changes to the look and feel of their breasts like a lump, puckering, dimpling of the skin, change in the position of a nipple, nipple discharge or new pain in one breast. Any of these changes should be reported to a doctor without delay.

We must make sure older women are aware that they are still eligible to be screened for breast cancer if they wish. Just as with younger women, older ladies should be offered information about the benefits and risks of breast screening so that they can make an informed choice about whether to be screened.

We don’t yet know precisely why older women are much less likely to receive surgery and radiotherapy for breast cancer than their younger counterparts. It may in part be down to poorer general health and different treatment preferences.  But women should be informed about the benefits of surgery and any woman who is fit enough should be recommended for it. This is certainly an area where more research will be needed.

This new study hasn’t given us all the answers. But it serves as an important reminder that, in this ageing country of ours, we need renewed efforts to ensure the best possible cancer outcomes for all, irrespective of age.

Hazel

• Watch Hazel Nunn talk about the research on YouTube

Reference:

Ali, A., Greenberg, D., Wishart, G., & Pharoah, P. (2011). Patient and tumour characteristics, management, and age-specific survival in women with breast cancer in the East of England British Journal of Cancer, 104 (4), 564-570 DOI: 10.1038/bjc.2011.14