Inflammatory breast carcinoma (IBC) is a very aggressive disease and accounts for less than 6% of all breast cancers in the United States. It is characterized by a rapidly progressive clinical course and diagnosed on the basis of distinct skin manifestations that are often confused with inflammation, hence its name. These manifestations include erythema, edema, skin nodules, and nipple retraction. A characteristic infiltration of the dermal lymphatics with tumor emboli is often seen by pathology but is not required to establish a diagnosis.
Although clinically more than 50% of patients do not have a detectable breast mass at the time of diagnosis, up to 85% have already metastasized disease that has spread to the regional lymph nodes, while more than 30% present with gross distant metastasis (1). Not surprisingly, owing to its high metastatic potential, IBC is associated with a 5-year overall survival (OS) rate of no more than 55% (2,3). Multimodality treatment in the form of neoadjuvant chemotherapy, surgery, and radiation aims to prevent metastatic failure as well as achieve local control.
The epidemiology of IBC has been a challenging area to study due to a number of factors. The rarity of the disease combined with its rapid progression and short OS mean that there are few single centers able to recruit an adequate sample of patients for investigation. In addition, confusion about its clinical definition has led to difficulties in comparing the results of different studies. As a result, the primary source of epidemiologic data comes from large national registries, which are limited by nonuniform data collection, inability to capture comprehensive details on risk factors, and in the case of IBC, varying case definitions.
To address these issues, the Morgan Welch Inflammatory Breast Cancer Research Program and Clinic at the University of Texas, MD Anderson Cancer Center (MDACC) spearheaded the development of an international IBC Registry. The IBC Registry prospectively collects tissue, serum, plasma, whole blood, imaging, clinical, and epidemiological data from patients with IBC, allowing a more comprehensive examination of the underlying mechanisms associated with the development of this lethal disease.
The incidence of IBC is reported to range from 1% to 6% of all breast cancers diagnosed in the United States (4). Higher proportions have been reported in North Africa, specifically in Tunisia and Egypt, where IBC accounts for 6% and 10% of all breast cancers, respectively (5,6,7). Data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program have demonstrated a rise in the incidence of IBC over time, although this trend seems to be slowing. Between 1973 and 2002, the incidence of IBC is reported to have increased at an annual rate that ranged from 1.23% to 4.35% per year, depending on the specific ...