Sandra Swain, MD, FACP, Medical Director of the Washington Cancer Institute, MedStar Washington Hospital Center, Washington, DC, moderated the San Antonio session where the dose-dense chemotherapy studies were presented, and commented on the findings of the two studies.
With regard to the iddETC trial, Dr. Swain joined several listeners in questioning whether the benefit was due to the dose intensification or to other factors, in particular, the taxane schedule. Other studies have shown, she said, that increasing the dose intensity of anthracyclines and also cyclophosphamides does not improve outcomes. “So, it’s probably the taxane that is making the difference [in the iddECT arm],” she suggested. In the iddETC trial, paclitaxel was given either every 3 weeks, which is known to be inferior, or every 2 weeks at the higher dose, she noted.
While a 10% difference in overall survival is “striking,” she acknowledged, because of the study design “you can’t determine if the benefit is due to the dose and schedule of the taxane or, in fact, whether it’s the dose-dense approach that makes the difference.”
She also pointed out that the estrogen receptor–positive patients benefited from the dose-dense, dose-intense strategy, whereas Cancer and Leukemia Group B (CALGB) 9741 did not show a benefit for dose-dense treatment in this subgroup. “I think this is interesting,” she said.
UK TACT2 Trial
As for the UK TACT2 trial, she pointed out that the study included “all comers” and half the patients were node-negative; therefore, this was a better population than the iddETC trial cohort with at least four positive nodes. This does not necessarily mean, she added, that dose-dense regimens are better in more high-risk patients.
“We also need to see the results of the randomization between capecitabine and CMF,” she added.
Dr. Swain further noted that the rate of venous thromboembolism in iddETC (13%) was much higher than what was observed in National Surgical Adjuvant Breast and Bowel Project (NSABP) B-38, a study she led, but as in B-38 the use of epoetin alfa was not detrimental to clinical outcomes. “This is reassuring,” she said.
Meanwhile, she said the results of the trials should not change practice. For physicians who like to use dose-dense chemotherapy, “don’t change anything,” Dr. Swain suggested. ■
Disclosure: Dr. Swain reported no potential conflicts of interest.
In the treatment of early breast cancer, dose-dense regimens (given every 2 weeks) have proven superior to conventionally dosed chemotherapy (given every 3 weeks), but data on long-term survival are lacking. Two studies presented at the San Antonio Breast Cancer Symposium evaluated the benefit of...