ORLANDO—Breast cancer experts gathered at ASCO 2009 to answer five important questions about anthracyclines, taxanes, HER2-positive disease, trastuzumab (Herceptin), and anti-VEGF agents. Their key message for adjuvant therapy: One size does not fit all. The participants were:
• Clifford Hudis, MD, chief of the breast cancer medicine service at Memorial Sloan-Kettering Cancer Center, New York.
• Martine Piccart-Gebhart, MD, PhD, director of the department of medicine at Jules Bordet Institute, Brussels, and EORTC president.
• Sandra Swain, MD, medical director of the Washington Cancer Institute, Washington, DC.
1. Are anthracyclines always necessary?
“Unquestionably, anthracyclines are inexpensive and effective in unselected patients, producing almost a 5% improvement in overall survival, but they have unique, serious, and potentially late toxicities,” Dr. Hudis said. “Can we avoid using anthracyclines? Should we phase them out entirely or safely replace them in certain cohorts?” (see Table on page 22). The answer is not a simple one because evidence for efficacy is observed in all subgroups. However, at least one recent study found nonanthracycline-based regimens to be as beneficial as anthracycline-based regimens.
In the seven-year follow up of US Oncology 9735 involving more than 1,000 patients, TC was superior to AC in disease-free survival (DFS) and overall survival (OS), Dr. Hudis noted (J Clin Oncol 27:1177-1183, 2009). But Japanese investigators confirmed that AC followed by a taxane was superior to a taxane alone (ASCO 2009 abstract 516).
In addition, a recent presentation by the NSABP of B-30 demonstrated that eight cycles of sequential AC followed by a taxane was superior to four cycles of TAC or AT. This suggests that the full doses of the components as afforded by sequential therapy improves outcomes and indirectly argues that a four cycle regimen like TC would be inferior to a standard sequence of anthracycline and taxane. “This keeps alive the concept that anthracyclines are critical components of adjuvant treatment,” Dr. Hudis said.