Conference Report on the 31st Annual San Antonio Breast Cancer Symposium, December 10-14, 2008 "Continuing Change in Diagnostics and Therapy of Breast Cancers - from Molecular Basics to Tailored Therapy"

The 31th San Antonio Breast Cancer Symposium confirmed the development away from risk-oriented therapies towards tailored diagnostics and treatment in breast cancer. As in the preceding years, results presented at the meeting focused equally on basic research and on preclinical and clinical studies. Disseminated tumor cells were a "hot topic" across such diverse areas as endocrine therapy, chemotherapy and targeted therapy. Additionally, differences in the origin of primary tumors and of metastases (metastasis suppressor genes and the differential response to therapy in an adjuvant and an advanced setting) were elucidated and discussed in specific review sessions. In the field of postmenopausal adjuvant endocrine therapy, aromatase inhibitors demonstrated their therapeutic superiority to tamoxifen, with concomitantly higher rates of side effects. The up-front use of letrozole in the BIG 1-98 study also failed to show a significant benefit in overall survival in the intention-to-treat analysis. According to the results of the TEAM trial, exemestane appears to be a further option for upfront endocrine treatment in postmenopausal breast cancer patients. The 36 month follow-up data of the ZOFAST trial confirmed a significantly lower decline in bone mineral density after treatment with zoledronate and demonstrated an improvement in disease-free survival. This could be attributed to a direct anti-tumor effect of zoledronate (AZURE). Neoadjuvant therapy using a combination of trastuzumab and chemotherapy in Her-2+ patients demonstrated significantly higher response rates and should therefore become a standard therapy. In advanced Her-2+ breast cancer patients, the benefit of treatment with trastuzumab after disease progression was confirmed. As already demonstrated for other small molecules and antibodies, the combination of lapatinib and letrozole is another option for hormone receptor and Her-2/neu positive metastasized breast cancer patients. New drugs such as Neratanib (a pan-tyrosine kinase inhibitor) or T-DM1 (a conjugate drug of Trastuzumab linked to deactyl maytansine) have demonstrated promising therapeutic effects and merit further investigation in breast cancer.