High level of EGF-R expression in carcinomatous skin invasion: Does it reflect the tissue characteristics of the breast carcinoma aggressiveness?

Background: The normal function and distribution of EGF-R and its role in breast cancer aggressiveness, prognosis and prediction, have become extremely important in the light of the recently developed methods of EGF-R targeting. In the aim to investigate the relationship between EGF-R and the aggressive tumor behavior, the EGF-R content was analyzed as related to the presence of inflammatory breast skin involvement. Methods: EGF-R, ER and PR content was determined at diagnosis, using the biochemical methods, in the group of 103 unselected breast cancer patients, either in primary tumors (TU), lymph nodes (LN) or skin tissue samples (65, 27 and 11 cases respectively). In 10 patients with inflammatory breast cancers, TU/LN tissue was sampled from 3, and skin from 7 patients. Results: ER and PR content was significantly higher in tumor and LN tissue, compared to the invaded skin the EGF-R content was, on the contrary, significantly higher in skin than in TU or LN tissue. However, no difference was found between TU and LN in all three receptors' content. When the receptor content was analyzed in 10 patients with inflammatory breast cancer, higher levels of both ER and PR were found in tumor biopsies than in skin biopsies, while for the EGF-R the result was opposite. Significantly lower ER content and a trend towards higher EGF-R content was found in the inflammatory breast cancers in comparison to the non-inflammatory ones. Conclusion: Although we examined a small number of patients, our results suggest that the EGF-R could be a marker of breast cancer aggressiveness. However, the influence of the normal skin cells contaminating the biopsied tumor tissue cannot be ruled out. The predictive role of EGF-R deserves to be further investigated especially in locally advanced inflammatory breast cancer patients