It was a small statistic in a straightforward report. But its impact and implications are potentially huge:
From 2000 to 2005, the percentage of women age 40 and over who received a mammogram within the previous two years fell from 76.4% to 74.6%, or 1.8%.
1.8% doesn’t seem like much, so why all the fuss?
Because in real terms, this means that thousands of women may have undetected breast cancer and will potentially miss the opportunity to save their lives.
This really wasn’t unexpected by those of us who try to keep up with current mammography practices.
My colleagues at the American Cancer Society noted a year ago that there had been a decline in mammography screening compliance. We were also aware that there appeared to be a decline in mammography in women on Medicare, a group that is at particularly high risk of developing breast cancer.
During the course of the past year, we have had discussions with several different groups, including insurers and quality assurance organizations, who were concerned about their own observations that mammography screening rates were dropping.
Then, at the San Antonio breast cancer conference in December, there was a stunning report that from 2002 to 2003 the number of new breast cancer cases diagnosed in the United States had actually decreased 7% (For my comments on this study, please see my blog entry for December 15.)
How does all of this fit together?
We have been making considerable progress in reducing deaths from breast cancer, despite what has been up until recently a continuing increase in the number of women diagnosed with this disease. More recently, the American Cancer Society has reported that the number of new cases diagnosed in year to year comparisons has actually appeared to be leveling off, the San Antonio report of a large decrease notwithstanding.
But what will happen in the future with respect to deaths from breast cancer, if the trend detected by the CDC continues, is a source of great concern.
We know that annual mammograms for women at risk for breast cancer significantly decrease deaths from this disease.
As I have mentioned in other blogs, none of the advances we have made in the treatment of breast cancer even begin to have value in the treatment of a woman’s breast cancer unless she starts by taking care of herself and getting a mammogram every year.
As a result of the widespread availability and uptake of mammography in the United States, we have been able to increase survival from breast cancer. Today, for a woman whose breast cancer is found early and has not spread to regional lymph nodes, the five year survival is 98%.
Let’s take a quick look at some numbers. These are just estimates for discussion purposes, but they at least will give you some perspective on the problem.
My colleagues tell me there are approximately 80 million women in the United States who should be getting a mammogram every year as recommended by the American Cancer Society.
But of those 80 million women, not all get an annual mammogram. In fact, we estimate that about 60% of women currently follow that recommendation (the CDC study looked at women getting a mammogram within the previous two years, which is why their numbers are higher than ours).
So, if there is a decrease in mammography compliance (as measured by the CDC standards), that would mean about 1.44 million fewer eligible women had a mammogram in 2005 compared to 2000.
Now, let’s take the next important step in this analysis.
My colleagues also tell me that the rate of breast cancer found on mammograms is about 4 to 6 per 1,000 mammograms per year.
If 1.44 million fewer women had mammograms, that translates into about (and these are very, very rough estimates) 5760 to 8640 women having a breast cancer that was not found in 2005.
Read that sentence again carefully: thousands of women have undiagnosed breast cancer that would likely have been found if they had a mammogram in 2005, as compared to 2000.
(Of course, we can’t forget that based on the CDC survey there are still another 20 million women who aren’t getting mammograms, and within that group there are many more thousands of women with undiagnosed breast cancer. But here we are trying to put into perspective only the impact of the decline in mammography.)
These aren’t breast cancers that don’t exist. These are breast cancers that exist and are not being diagnosed.
Why are we seeing this decline? Frankly, we don’t have all of the answers.
We know that the number of doctors specializing in mammography is declining.
We know that in some areas of this country women are having problems getting access to mammograms in a timely manner.
We know that women who don’t have health insurance or are less educated have a lower rate of mammography.
When the large decline in breast cancer incidence from 2002 to 2003 was reported in December, there was much speculation by experts interviewed in the media that this was due to the fact that women discontinued hormone replacement therapy as a result of a report in July 2002.
My own opinion, as I expressed in my blog entry at the time, was that although this may have had some impact, it wasn’t logical to assume that every woman stopped her hormones right after the article was published, and that breast cancers stopped occurring.
I thought that, although the decrease in HRT may have had something to do with declining diagnosis, there were likely additional explanations, including a decrease in the growth rate of some already-existing cancers.
And, I noted, declining mammography utilization was quite possibly one of those reasons.
So what is going to happen as a result of the observations in this current CDC report?
First, and most concerning, is that this may be just the tip of the iceberg and that this may be a very unwelcome trend. In a sense, these numbers may be the canary in the coal mine. We will certainly want to follow this very carefully.
Next, we need to understand exactly what is behind this decline. Is it limited to certain groups of women? The need to know why this is occurring is critical to our understanding of what we need to do to fix the problem.
For example, we know that only 1 in 5 eligible women in this country are able to take advantage of the CDC’s National Breast and Cervical Cancer Early Detection Program, which provides access to mammography and cervical cancer screening for underserved women. This program has proven its effectiveness, and it saves lives but it is underfunded and underutilized.
One of the issues that has not been talked about frequently is the possibility of compliance fatigue.
I have observed among my doctor colleagues that they are not doing all they could to see that their patients get recommended screening and prevention studies. After all, they have a lot on their plates, and prevention has a tendency to fall to the bottom of the priority scale in our current health care system. It is hard for docs to quantify the benefit to society of the screening recommendations they make to their patients.
Well, if that is happening to doctors, why would we think it couldn’t happen to patients as well?
Women who are 60 or 70 today and have been compliant with screening recommendations have been getting a mammogram every one or two years since the 1990’s or perhaps earlier. After a while, it would seem logical to most people that you just don’t have to go every year. It is inconvenient to go to the doctor’s office, and a mammogram is not the most fun thing a woman can do with her spare time.
But that is a dangerous assumption. Breast cancer is a disease of aging, and the risk increases as you age. So if you think you don’t have to go because the last 20 studies have been fine, you are misleading yourself when it comes to your risk of breast cancer.
Mammograms don’t prevent breast cancer—they find it early in most cases. So, the more mammograms you have doesn’t mean you are at less risk of finding breast cancer on the next study as you get older. (I am assuming for this comment that a woman goes every year, as opposed to a woman who goes every 5 years, for example.)
A comment on my blog from a breast cancer survivor noted that she was concerned that women were becoming complacent about getting a mammogram because they stopped their hormone therapy.
First, let’s point out that the increased risk of breast cancer was found with combination hormones and not so much with estrogen alone.
Second, the risk of breast cancer for the average woman is only slightly increased because of the hormones. Almost all of the risk of getting breast cancer for any one woman is simply due to the fact she is a woman, and is getting older (assuming there is no significant family or genetic history).
And then there is the final issue that needs to be addressed: Is all of the publicity that has questioned the value of mammography having a negative impact on the behavior of women?
Study after study has demonstrated the value of mammography. We have seen declines in death rates from breast cancer, in no small part due to the contributions of mammography. The American Cancer Society stands behind its firm recommendation that women need to get mammograms.
But we also know that when the public message gets muddled, people react by ignoring the recommendations. That is one of the problems we face in public health.
Despite very clear recommendations by many authoritative organizations, the negative publicity in the recent past may have confused the public and contributed to complacency.
If that’s the case, that is unfortunate because women will pay with their lives.
Going forward, as I mentioned above, these breast cancers are not going to go away. They will continue to grow, and they will eventually be diagnosed.
But I for one would hate to see us slide back to the good old days when almost every breast cancer patient I saw in my practice found their cancer by feeling it in their breast.
Those good old days were associated with larger cancers that spread into the lymph nodes and not infrequently into other parts of the body. They were beyond hope of cure, or certainly at greater risk of recurrence following diagnosis.
That is one part of the good old days that I would like to leave behind.
But if we continue to see fewer women getting mammograms, then it is inevitable that we will see the tides turn in the wrong direction.
That won’t be evident for several years, but it is likely going to happen unless we reverse this trend.
And that would be tragic.