According to the results of a Phase III clinical trial published in the Journal of Clinical Oncology, concurrent administration of chemotherapy and radiation therapy may reduce the risk of cancer recurrence in or near the breast in women with node-positive early breast cancer.
Early breast cancer refers to cancer that has not spread from the breast or axillary (under the arm) lymph nodes. Many women with early breast cancer choose to undergo breast-conserving therapy, which includes the removal of the cancer and surrounding tissues and evaluation of axillary lymph nodes, followed by radiation therapy. Alternatively, some women may undergo mastectomy and axillary lymph node evaluation. Women may also receive chemotherapy and/or hormonal therapy.
To explore two different approaches to the timing of chemotherapy and radiation therapy after breast-conserving surgery for early breast cancer, researchers in France conducted a Phase III clinical trial among 716 women with Stage I or Stage II breast cancer.
Half the study participants received sequential chemotherapy and radiation therapy and half the study participants received concurrent chemotherapy and radiation therapy. In the sequential therapy group, radiation therapy started three to five weeks after the final cycle of chemotherapy. In the concurrent therapy group, both treatments started at the same time. The chemotherapy regimen that was given to both groups of patients consisted of mitoxantrone, fluorouracil, and cyclophosphamide.
Half the patients have now been followed for more than five years.
- Overall, there were no differences between study groups in cancer-free or overall survival.
- In the subset of women who were node-positive, concurrent chemotherapy and radiation therapy resulted in a lower risk of locoregional cancer recurrence (cancer recurrence in or near the breast) than sequential chemotherapy and radiation therapy. Risk of locoregional recurrence was 39% lower in women who received concurrent therapy.
The researchers conclude that among women with high-risk early breast cancer, concurrent administration of chemotherapy and radiation therapy may reduce the risk of cancer recurrence in or near the breast. The researchers note that this study used a chemotherapy regimen that is no longer commonly used, and that additional studies with more recent chemotherapy regimens are warranted.
Reference: Toledano A, Azria D, Garaud P et al. Phase III trial of concurrent or sequential adjuvant chemoradiotherapy after conservative surgery for early-stage breast cancer: final results of the ARCOSEIN trial. Journal of Clinical Oncology. 2007;25:405-410.