Angela Georgopoulos

inflammatory vs non-inflammatory breast cancers in Egypt

BACKGROUND: Inflammatory Breast Cancer (IBC) is a very aggressive and rare form of locally advanced breast cancer that has a rapid onset of disease and is clinically characterized by edema, redness, and dimpling of the skin (peau d'orange). With about a 20-40% three year survival for IBC as opposed to an 85% survival for other breast cancers, IBC is also the most lethal form of primary breast cancer. However, clinical symptoms are not always found in diagnosing all IBC cases. Therefore, genetic characterization is important for its diagnosis. The over expression of the Rho-C guanosine triphosphatase (GTPase) gene, among multiple other possible genetic mechanisms, helps contribute to the IBC phenotype.

OBJECTIVES: The objective of this study was to further the understanding of the differences between IBC and non-inflammatory breast cancers, with a particular focus on Rho-C GTPase gene expression.

METHODS: We recruited 63 IBC cases from January- December 2005 and 67 non-IBC cases from the National Cancer Institute in Cairo, Egypt from the same period. We identified non-IBC cases by reviewing medical records and pathology reports of all 1893 breast cancer patients in 2005 and using the following inclusion criteria: the tumor had to be 5 cm or greater and they were additionally matched by age to the IBC patients. Both IBC and non-IBC patients came from rural and urban areas of Egypt. For all paraffin blocks for all patients, slides were cut and one slide was stained with Rho-C antibody and then scored for gene expression. In terms of Rho-C gene expression, a score of 0 or 1 indicates that the cells were devoid of RhoC protein and thus there was nothing for the stain to adhere to. Alternatively, a staining score of 3, and particularly 4, indicates that there was an overabundance of RhoC protein for the stain to fasten to.

RESULTS: 33.3% of IBC patients were scored with a 4 and 42.86% were given a score of 3, indicating moderate to heavy staining. Interestingly, 15.87% were scored at a 2 and 7.94% were given a score of 1. In contrast, only 1.5% of the non-IBC controls were scored with a 4, 9.0% were scored with a 3, 40.3% were given a Rho-C score of 2, and 49.25% were given a score of 1, indicating little or no staining (P < 0.0001).

CONCLUSIONS: The results yield evidence supporting the initial theory that expression of certain genetic factors, particularly Rho-C, is characteristic of IBC tumors.