Are mammograms failing women?

Since the national breast cancer screening program now known as BreastScreen  Australia was introduced in 1991, 56 per cent of eligible women, those aged 50  to 69, have taken up their invitation for a free mammogram. In June the federal  government announced a $55 million boost to expand the free screening age to 74.  Thousands more women pay for private clinic screening.

It is these women, in the age group most at risk, who are familiar with  having their breasts squeezed between the cold plates of a mammogram machine so  that the tissue might be X-rayed for abnormalities.

Early detection by mammogram screening has seen the number of new breast  cancer cases in this country more than double between 1982 and 2008.

According to last year’s Breast Cancer in Australia: An Overview, a  report released by the Australian Institute of Health and Welfare and Cancer  Australia, breast cancer is now the second most common cause of cancer-related  death (lung cancer is the first). Seven Australian women die every day from  it.

For many healthy women, taking part in regular mammogram screening has become  synonymous with taking active responsibility for their health, as if early  detection has become fused with the idea of a cure. It’s as though all that pink  “feel-good” awareness has turned having a mammogram into a trusted form of  self-protection, a modern symbol of hope against cancer’s malignant stealth.

According to BreastScreen Australia, since Australia-wide mammogram screening  was introduced 22 years ago by the federal government, breast cancer mortality  rates have declined by 29 per cent. But there’s a growing number of clinicians,  researchers and academics who argue that developments in cancer treatment over  that same period are just as likely to be responsible for the drop in deaths as  mammogram screening. Moreover, some suggest our obsession with tracking down  early breast cancers means an otherwise indolent or slow-growing tumour that  might cause a woman no harm in her lifetime will be unnecessarily treated.

“Over-diagnosis is a psychologically delicate issue,” says Professor Robin  Bell, deputy director of the Women’s Health Program at Melbourne’s Monash  University School of Public Health and Preventive Medicine. “To even contemplate  that [treatment] may not be absolutely necessary is extremely upsetting.”

Bell is at pains, however, to distinguish between women at higher risk who  should definitely consider treatment. “[Actor] Angelina Jolie, for example, knew  she had a particular genetic trait and that put her at much higher lifetime  risk. It’s important that people don’t think every woman is in the same boat … [but] a lot of women have assumed because they have the invitation to breast  screen that it’s all benefit and no risk.

“We have an obligation to ensure they fully understand the issues that come  with screening, such as false positives, and other issues that are more poorly  understood, such as under-diagnosis and over-diagnosis. In the past, the  messages [about the value of mammography screening] have been very strong and  persuasive, but I think we need to balance that information so that women can  weigh up the decision for themselves.”

Since 2003, the National Health and Medical Research Council has funded  $148.3 million in research into breast cancer, including $20.5m last year  alone.

But here’s the tricky part: for all the millions of dollars spent on  research, doctors usually don’t know which early forms of breast cancer will go  on to be invasive and potentially life-threatening, and which will not. So, if  you are a woman who turns up for your two-yearly free mammogram screening to be  told you have an early form of non-invasive breast cancer, what are you to do?  What nerveless woman is going to adopt a wait-and-see approach?

Most women would be scared out of their wits and wish to immediately embark  on a proactive course at the earliest opportunity, whether or not treatment  turns out to be necessary. Here’s the rub: “We’re unable to tell which diseases  might never have developed, and which will,” Bell says. “What we do know is that  there will be women who are overdiagnosed … but we just don’t know which  ones.”

Lisa Jansz, 47, of The Gap in Brisbane’s west, was diagnosed with an early  form of breast cancer after a mammogram six years ago and doesn’t care about  over-diagnosis. “I would have had chemo every single day of the week if I  thought it was going to keep me alive,” Jansz says.

 

EARLY DETECTION OFFERS THE BEST HOPE OF CURING DISEASE, AND CERVICAL,  prostate and breast cancer screening programs all actively go looking for cancer  in outwardly healthy people with no visible symptoms. Before mammogram  screening, breast cancers were usually discovered as lumps, by women or their  partners or their doctors. Now mammograms can find cancer before it is  technically invasive, while it is still in that abnormal state between a normal  breast cell and a cancerous one.

Mammograms are considered to have achieved an effective outcome when they  identify areas of abnormally high breast density that may be cancer, and which  show up on X-rays as white matter. It’s considered not particularly useful for  younger women to have mammograms as their breast tissue is denser, making X-rays  harder to read.

Jansz was 41 when she asked her GP for a mammogram. In her job as a breast  cancer theatre nurse at the Wesley Hospital in Brisbane’s inner west, she had a  heightened awareness of the disease but also wanted a mammogram because it was  just one of those things she wanted to check off her to-do list, much like an  annual dental check-up and a regular pap smear.

“Some of my friends, the girls I hang out with socially, were a couple of  years older than me and they’d all had them. I went to my GP for something else  and I just happened to mention it: ‘Oh, can I have a mammogram? All my friends  have had one!’ ” Jansz never expected anything but an all-clear.

She was on her way to a party at a friend’s house when she got a call from  the doctor asking her to return. “I still didn’t think it was going to be  anything, [as] it’s quite common [to be called back].” She knew she was younger  than the usual age for a mammogram and therefore more likely to be among those  10 per cent of women recalled for further tests because of inconclusive results,  only to be subsequently told that they do not have cancer. These fortunate  outcomes – following much anxious waiting – are known as “false positives”.

But Jansz was not so lucky. After a biopsy she was found to have ductal  carcinoma in situ (DCIS), abnormal cells in one or more of the milk ducts that  have not yet invaded other parts of the breast. Sometimes DCIS is classified as  “pre- cancerous”, or – in the United States – “stage zero” breast cancer, but  all Jansz knew was that she was suddenly frightened.

“I was devastated, I just couldn’t believe it,” she says. “They said it was  pre-cancerous but as far as I’m concerned it’s still breast cancer. It was  treated with a lumpectomy and radiotherapy but by then I was obsessed, totally  obsessed. When I was first diagnosed I thought I was going to be dead in two  years, I was a bit of a basket case for a little while. I’d be awake all night,  feeling, prodding, poking, and that’s how I found the next one myself [in the  other breast] by sheer feeling, prodding and poking. That one was a more  aggressive tumour, malignant.”

Jansz says her marriage broke up under the pressure. She and her former  husband had immigrated to Australia from Britain in the early ’90s with their  two pre-school-age daughters, Maddie (now 21) and Francesca (now 19).

One shining moment for Jansz amid the trauma of fronting up for surgery to  remove the tumour in the other breast and to check that no lymph nodes were  affected (they weren’t) was that she was surrounded by the familiar surgeons and  nurses she had worked with for years.

Jansz did not require a mastectomy. She’s now back working again, in a new  relationship and is happy. If the experience hasn’t made her a better breast  cancer theatre nurse, it’s possibly made her a more empathetic one. “When  patients come in and they’re crying on the table because of what’s ahead of  them, I totally understand where they’re coming from,” she says. “I don’t say,  ‘Look, I’ve been there and I’m still here’, because it’s not the sort of place  to say that. I just hold their hand and wait till they’re asleep. I just know  what they’re thinking. It’s very scary, it’s horrible.”

Jansz says a mammogram saved her life. “If I hadn’t asked my GP for one, who  knows what would have happened? This stuff was going on inside me and I had no  idea. It could have been a completely different story if I hadn’t had one.”

 

ACCORDING TO THE MOST RECENT FIGURES FROM THE AUSTRALIAN INSTITUE of Health  and Welfare, Lisa Jansz represents one of approximately 1600 Australian women  diagnosed annually with DCIS. It is these women in particular, with low-grade or  abnormal cells, whose disease is picked up early through mammogram screening,  who are most likely to face possible over-diagnosis (or over-treatment).

Usually surgeons do not know the extent or grade (high or low) of DCIS  disease, or whether it is contained or has spread beyond the margins of the  site, until after a woman has gone through the trauma of surgery. And Dr Helen  Zorbas, CEO of Cancer Australia, admits that “determining exactly which types of  DCIS are linked to increased risk of developing subsequent invasive breast  cancer remains a key question for future research”.

Professor Alexandra Barratt of the School of Public Health at the University  of Sydney’s Medical School is one of the authors of a study on over-diagnosis in  breast cancer screening published earlier this year in The British Medical  Journal. In an interview with Qweekend, Barratt quoted a 2012 US  study of data over 30 years, published in The New England Journal of  Medicine, which estimated as many as 1.3 million women were over-diagnosed  and received cancer therapy they didn’t need.

In her own study of Sydney women, Barratt and her colleagues found that the  general public – and in particular women undergoing mammograms – were largely  unaware of the concept of over-diagnosis.

“The over-diagnosis issue is an extraordinarily complex one,” Barratt says,  adding that she and her colleagues are sensitive to the possibility that debate  about the downsides of mammography screening may cause women to regard them  outright as unnecessary. “It’s a really difficult, complex topic that puts  women, doctors and policy-makers on the horns of a dilemma.” She says while they  know there is overdiagnosis across the population “we can’t pinpoint which women  are over-diagnosed”.

Barratt says when mammography screening was introduced, there was evidence  only of its benefits. “It’s only in the past 20 years that the evidence has  accumulated and now over-diagnosis is the main harm. Problems arise if a cancer  is slow-growing, or even harmless, and it’s found by screening, because we can’t  tell which cancer is indolent and which is fast-growing. As a result, everyone  is treated, and this leads to over-treatment.”

Barratt says the questions that need to be asked are whether over-diagnosis  is a reasonable price to pay given the undeniable benefits of mammography, and  how those benefits are balanced against the harms.

“I think the evidence is that the benefits are not as big as we first  thought, and in fact the harms are more substantial and more frequent than we  thought. The Cochrane review found that screening increases the number of  mastectomies and number of women needing radiotherapy.”

The Cochrane Collaboration, an international NGO and World Health  Organisation assembly member specialising in medical research and data, this  year published an extensive review of trials of mammogram screening, compared  with no screening, of more than 600,000 women in dozens of countries, including  Australia.

It found that over-diagnosis and over-treatment were at 30 per cent, meaning  that for every 2000 women invited for screening over 10 years, one would avoid  dying of breast cancer and 10 healthy women, who would not have been diagnosed  in the absence of screening, would be treated unnecessarily. Additionally, more  than 200 women would experience “important psychological distress, including  anxiety and uncertainty, for years because of false positive findings”.

Barratt has no desire to scare women into not having mammograms. “From the  evidence I think it’s reasonable for women to decide, ‘Yes, I want to do this,  to reduce my risk of dying from breast cancer’, but it’s also reasonable for  women to look at the evidence and decide, ‘No, I don’t want to do this’. But for  that to happen, we need to have good-quality information available to  women.”

Dr Helen Zorbas says Cancer Australia aims to support effective messaging  around issues of public health. “In that regard we’re working with the federal  government and with the BreastScreen Australia program to develop information to  assist women in deciding whether or not to participate in screening.” She says a  resource is currently in its final stages of development, one that aims “to  support women’s decision-making around participating in screening [and to]  provide as much information as possible around the potential benefits, as well  as the potential downsides, of screenings”.

One of the major downsides of screening, identified by the Cochrane  Collaboration review, was that the increased use of radiotherapy may increase  mortality in women considered to be low-risk. This is because of latent damage  to the coronary arteries and possible heart damage resulting from some types of  radiotherapy. “This heightened mortality becomes important when many healthy  women are over-diagnosed,” the report said.

Professor David Roder, of the University of South Australia and a senior  adviser in population health at Cancer Australia, argues that in medicine, as in  other areas of society, doctors can only do the best with what they know at the  time.

“Over-diagnosis will happen,” he says, “so the issue really is, how can we  minimise it? It requires a research effort in order to say, ‘Well, here’s a  cancer that we can safely leave’. One wouldn’t be inclined to do that without  good evidence, to leave something that otherwise looks malignant inside a  person, so we need good evidence. I agree it’s a research priority, but it’s an  international one that’s being pursued all over the place to try to better  define those cancers.”

For now, Roder believes the positive result of mammography on mortality is  “pretty much without question in Australia”. “We’re lucky to have a continuum of  studies that show quite a profound impact in reducing deaths,” he says. “What  breast screening achieves is dependent on the quality of the program that’s  delivering the screening, so I think it’s really important when you make  judgements about the benefits of screening in Australia that we look at our own  results and not at results from other places where they have different  protocols, different quality controls, different training.”

Zorbas says Australia enjoys some of the best, if not the best, survival  rates for women diagnosed with breast cancer anywhere in the world. “There is a  clear relationship between stage of diagnosis and survival, so the earlier the  cancer is detected and treated, the better the survival outcome. We have seen  significant improvements in the five-year survival rates for women with breast  cancer in Australia. Just 25 years ago, 72 per cent of women were alive five  years after diagnosis; we now have 89 out of every 100 women alive five years  after diagnosis, and that’s across all stages of the disease.”

In the future, mammogram screening may come to be seen as a crude instrument  in diagnosing cancers. The National Breast Cancer Foundation, for example, is  funding a study to investigate blood testing as an early cancer detector. Monash  University’s Professor Robin Bell is convinced that in years to come, “blanket  screening of all women over the 20 years of mid-life will appear a very crude  way of identifying breast cancer”. But for now, it’s all we have.

 

“IF IT’S NOT CANCER, THEN WHY AM I SO WORRIED?” ASKED HERVEY BAY primary  school teacher Rachel Aspinall, 47, on a breast cancer blog two-and-a-half years  ago following her own diagnosis with DCIS.

The mother of four children (Jenny, 19, Mark, 18, Katie, 17, and Gary, 11)  had never heard of DCIS, so she set about Googling everything she could find.  But the more she found out, the more confused she became.

“It puts you in a bit of a dilemma when you start to read about it online,”  she says. “Some sites say that it’s not even cancer, but pre-cancer. I was so  confused.”

Aspinall had been having mammograms since she turned 40, because an elder  sister, Miriam, had been diagnosed with breast cancer. Throughout, she had the  support of her husband, Philip, a project manager, and together they decided to  opt for treatment (her DCIS subsequently proved to be high-grade).

“I’d rather take the chance and have treatment than wait 12 months and find  out that it’s an aggressive cancer that has spread,” Aspinall says. “I tried to  make an informed decision, asking my surgeon, and also talking to a plastic  surgeon [about a possible mastectomy]. I talked to him, and to a radiation  oncologist, prior to making a decision. In the end I had enough confidence in my  surgeon, and in between talking to her and reading as much information as I  could, I made the decision to go down the lumpectomy and radiation route.”

Aspinall believes in the value of independent research. Her advice for other  women? “Don’t be bullied into jumping into anything. Speak to doctors, more than  one if necessary. Screening is important; just don’t rely on it 100 per  cent.

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