Over the past few weeks, conflicting reports about the effectiveness of screening mammography in breast cancer prevention have hit the media spotlight. As Breast Cancer Awareness Month continues, we asked surgical oncologist Alisan B. Goldfarb, M.D., F.A.C.S., a member of our WVFC Medical Advisory Board, to evaluate the coverage of recent studies in this area. Here, she weighs in on two New York Times articles on the topic.  –Ed.

Why is it that the New York Times has a fixed attitude about screening mammography? On September 23, 2010, the headline on a front page story read: “Mammogram’s Value In Cancer Fight At Issue.” The article reported on a study that would appear in the New England Journal of Medicine the following week and gave a very opinionated review of it. Then on September 30, buried on the bottom half of page 24, an article appeared for which the headline was: “Mammogram Benefits Seen For Women In Their 40s.” In print almost as large as the headline, a call-out in the middle of the article read: “A Swedish study found fewer cancer deaths but other experts disagreed.”

What I don’t understand is why, in the news portion of the paper, there is so much opinion being expressed–particularly by one writer, who authored both articles. The first study comes from Norway and takes advantage of the fact that, before the 1990s, there was no coordinated breast cancer care, and breast cancer screening had not yet been established. The coordinated care of breast cancer was established throughout that country just prior to 1996; that year, they began doing screening mammography for women between 50 and 69 on a once-every-two-years basis. But not all the counties in Norway began screening at once. This allowed them to compare, within in the same county, the death rate from breast cancer over a ten-year period, starting long before there was coordinated breast care and after such care was in place. They could also compare the combination of coordinated breast care and mammography with a similar control group from the same area.

The findings were not a real surprise. A substantial decrease in deaths from improved cancer treatment was seen almost immediately and, since the follow-up period was very short, that was a good thing. The follow-up period was as little as two years in many patients, and less than nine years in the whole group. The addition of screening did improve the breast cancer survival rate during that short follow-up period, but not as dramatically as the increased care. The Times article goes on to note that it’s clear that mammography is not as useful as we thought because of the great new treatments available, and therefore, it’s not necessary to find breast cancers early.

Their conclusion is, of course, not correct. In order to see the impact from screening mammography, we would have to wait much longer than the short follow-up period in the Norway study. This has been very well-shown in many of the earlier studies on screening.

We also have to remember that the goal of the screening mammogram is to find small cancers, maybe even pre-invasive cancers, so that patients can be treated for cure without chemotherapy. The notion that these small cancers would never amount to anything, and that we are treating people who do not need treatment, is often mentioned when talking about the downside of screening.

I would like to know what these lesions are. I have not seen, in 30 years, a small cancer that I could guarantee would not go on to become a problem in the future, nor have I ever been unhappy to find a cancer that could be adequately treated without chemotherapy. We should not have to wait until lesions are big enough to feel in order to diagnose them, because that condemns even the less aggressive tumors to a course of chemotherapy and, for the most aggressive tumors, we will probably lose our opportunity to cure those patients.

The most aggressive cancers can spread very early and both chemotherapy and radiation therapy are what we call burden-dependent therapies. They are much more likely to be successful if there’s a minimal amount of disease present. I must strongly say that I’m completely at odds with the interpretation of the data as the New York Times presented it, which I will also point out is not how the author summed up the article. The author stated that having coordinated care and modern treatment have had a larger short-term effect on the mortality rate, but that screening mammograms are still making a considerable contribution.

The study reported in the Times on September 30 is one that has not yet been published but will appear in the journal Cancer. This research, done in Sweden, again takes advantage of the fact that some counties introduced screening mammography for women starting at the age of 40 and others did not. The researchers were able to follow the change in the mortality rate; they noticed a 26 percent lower rate in the counties with screening. Instead of simply reporting this, the Times again editorialized and got opinions from other researchers, who took exception with the findings. Those other researchers said that the analysis was flawed because the mortality rate would not be affected by finding and treating the cancers that would, in the future, have been harmless.

Once again, the notion that cancer can be harmless if left alone is one that has never been shown to be true. Until we find a way to prevent breast cancer at the molecular level, or find a test which is more sensitive and more specific than a mammogram, mammography remains our single best tool for early detection which, if followed for the long-term, will result in a much lower mortality rate from breast cancer.

As medical students, we are told that in reading medical literature, never to read just the conclusions of the author, but to read through the paper to see what data was looked at and how those conclusions were drawn. I must express great disappointment that in both articles, the journalist was not even accurately reporting the conclusions of the research that she was reporting on. I am reminded that, perhaps, a newspaper is not the best place to obtain medical information and advice.

Join the conversation

This site uses Akismet to reduce spam. Learn how your comment data is processed.

  • b.elliott October 14, 2010 at 12:25 pm

    Thank you so much for sharing your informed opinion. There is so much information and misinformation out there. What you have written makes so much sense.

    Reply