parameters guide tumor treatment decisions, as well as the disease prognosis evaluation (Arnone et al., 2010). It is likely that BC classification may require revision, as a recent cDNA microarray gene expression profiling study has classified BC into 5 distinct subtypes based on variations in gene expression patterns (Haupt, 2010). These 5 subtypes are luminal A and luminal B, normal breastlike, HER2 overexpressing, and basal-like subtypes (Nielsenet al., 2004;Haupt et al., 2010). BC treatment commonly follows combinatory schemes comprising surgery, radiotherapy, chemotherapy, and/or hormonotherapy. Surgical strategies of breast tumors vary according to the extent of the disease, which is evaluated as in situ carcinoma or invasive cancer. Lobular and ductal in situ carcinomas are treated, respectively, with excisional biopsy then prophylactic use of tamoxifen, or another hormonotherapy approach, for five years (depending on the tumor ER status), and mastectomy followed by radiotherapy. Partial mastectomy may also be considered. Although the discussion of BC surgery is beyond the scope of the present work, it is worthwhile to point that the decision to pursue with mastectomy, partial or radical, must consider that its curative benefit overpasses its mutilation impact on women's psychological health (Barros et al., 2009). On the other hand, invasive BC carcinomas are differentially treated depending on the tumor size, free surgical margins and residual post-surgical disease, skin damage, and the existence of metastasis. When BC is diagnosed as a tumor of 3 cm or less with free surgical margins, the recommendation is conservatory surgery, characterized by segmentar resection, followed by radiotherapy (Veronesi et al., 1995). Axillary linfadenectomy dissection is also advised whenever sentinel lymph node (SLN) tests positive for malignancy, as it indicates lymphoid drainage of the primary tumor micrometastasis (Fisher et al., 1997a). Nonetheless, invasive BC carcinomas larger than 3 cm at the disease diagnosis, both mastectomy and linfadenectomy are indicated. Breast reconstitution may be considered for patients presenting good clinical conditions (Barros et al., 2009). Regarding the conventional pharmacologic control of BC, there are several multidrug regimens preconized for neoadjuvant, adjuvant, or palliative chemotherapy approaches. As for any other antineoplastic approach, BC chemotherapy combines drugs with distinct cytotoxic mechanisms of action aiming the avoidance of drug resistant phenotype development by cancer cells. In this context, current BC chemotherapy schemes include drugs classified as anthracyclines, alkaloid taxanes, nitrogen mustard alkylating agents, antimetabolic drugs, and hormonotherapeutic agents. Of interest, the relevant pharmacodynamic aspects of the cited drugs will be briefly addressed [Drugs mechanisms of action have been reviewed by Brunton (2010)]. Anthracyclines, which include doxorubicin and epirrubicin, are considered cytotoxic antibiotics that comprise a tetracycline ring cou...