Is Inflammatory Breast Cancer As Rare As Everyone Thinks?

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Experts say that 1 in 8 women will develop breast cancer in their lifetime. Taken as a whole, the odds for long-term survival are good -- nearly 90%. For a subset of these women, the future is not so hopeful. These are women with the most aggressive form of breast cancer, called inflammatory breast cancer (IBC).

For women with IBC, the odds are much less optimistic -- a five-year survival rate of 40%; no better than a 10-year survival rate of 25%. According to published epidemiologic data, IBC represents from 1% to 6% of breast cancers. While other breast cancers have been on the decline, IBC has been on the rise.

Where do the numbers come from?
Hospitals around the world track detailed cancer data. Major hospitals participate in national tumor registries, which in turn feed international databases. From these data repositories, valuable population-based information can be gleaned.

In the United States, our cancer registry is the National Cancer Institute (NCI) Surveillance Epidemiology and End Results (SEER) Program. This organization, with advisors from professional medical societies, determines what criteria will be used to code each type of cancer.

How reliable are the numbers?
Inflammatory breast cancer is primarily a clinical diagnosis, dependent upon the expertise of the health professional. That means that the physician differentiates between IBC and other breast cancers based on how the breast looks upon examination, how the symptoms started and how quickly it progressed.

Pathology reports based on tissue samples are able to confirm the presence of cancer cells. That's absolutely necessary to rule out other causes of the physical symptoms of IBC. Especially in IBC, getting a good specimen can be tricky. IBC is on the skin and in the lymph system and rarely forms a lump. Further complicating the pathologic diagnosis is that there's no way to tell IBC from any other type of breast cancer. That brings us back to the clinical diagnosis.

In 2007, SEER implemented a change that has the potential to adversely affect the number of IBC cases. The new rule states that inflammatory carcinoma of the breast should only be recorded in the registry if the final diagnosis of the pathology report specifically states inflammatory carcinoma. These guidelines have been adopted by all state cancer registries and the National Cancer DataBase (NCDB) of the American College of Surgeons, as well as the SEER registries. This change means many cases diagnosed after Jan. 1, 2007, will not be tagged as IBC. This may lead to false conclusions about the incidence of IBC.

Last year, data were presented at the International Inflammatory Breast Cancer Conference that examined the impact of the new SEER coding criteria on IBC cases documented in M. D. Anderson's tumor registry over the last few years. It showed that if the coding criteria were applied to the 247 IBC cases, only 30% of them would be classified as inflammatory breast cancer. This means that current statistics underestimate the incidence of IBC.

Why are numbers important?
Because of the relative rarity of inflammatory breast cancer, little emphasis has been placed on developing drugs that work specifically for IBC. Until very recently, research dollars have been hard to come by. Pharmaceutical companies, not perceiving a large market, are reluctant to fund clinical trials.

Despite the lack of resources, more and more women are becoming aware of "the breast cancer without a lump," also dubbed "the silent killer." Thanks to advocacy groups such as the Komen Foundation and the Inflammatory Breast Cancer Foundation, their voices have become loud enough to be heard. Clinics and hospitals are beginning to dedicate resources to develop treatments and look for causes.

We can't go back. We can't give up. Without a more accurate picture of the number of cases, the risk of IBC being once again relegated to the untreated and unknown looms large.

Our center, for one, will continue to classify IBC based on clinical observation. At the same time, we will continue to explore better methods of diagnosing IBC, including looking for specific characteristics of IBC cells, developing advanced imaging techniques so that our doctors can "see" the cancer and, ultimately, identifying the markers of IBC that can be detected by a simple blood test.

We have a long way to go, but we are determined to "teach it, treat it and beat it."

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