SABCS 2015: Capecitabine Improved Outcomes for Breast Cancer Patients With Residual Disease After Presurgery Chemotherapy
Treatment with the chemotherapy agent capecitabine increased disease-free survival for women with HER2-negative breast cancer that was not eliminated by presurgery chemotherapy, according to results from the phase III CREATE-X clinical trial presented at the 2015 San Antonio Breast Cancer Symposium, held December 8–12 in San Antonio, Texas (Abstract S1-07).
In some patients with breast cancer treated with neoadjuvant chemotherapy, residual invasive cancer can be detected in breast tissue samples and lymph nodes removed during surgery. These patients tend to have worse long-term outcomes compared with women who respond completely to neoadjuvant therapy.
“It has been suggested that patients with residual invasive disease after neoadjuvant chemotherapy have chemoresistant breast cancer, but there have been no large-scale clinical trials to test whether adjuvant systemic chemotherapy is beneficial for these patients,” said Masakazu Toi, MD, PhD, Professor at Kyoto University Hospital in Japan, and Founder and Senior Director of the Japan Breast Cancer Research Group (JBCRG). “CREATE-X was designed to evaluate this clinical question by testing whether capecitabine could improve disease-free survival for patients with residual invasive disease after neoadjuvant chemotherapy.
“These first efficacy results show that after 2 years of follow-up, disease-free survival is significantly improved by addition of capecitabine to standard therapy,” continued Dr. Toi. “These data are exciting, because the side effects of the treatment were manageable and the benefit of capecitabine treatment was clear.”
Study Findings
Dr. Toi and colleagues enrolled 910 patients in the trial, all of whom had HER2-negative breast cancer and residual invasive disease after neoadjuvant therapy that included an anthracycline and/or a taxane. All patients received standard treatment—hormone therapy or chemotherapy, depending on hormone-receptor status—and were randomly assigned to capecitabine or no additional therapy. The 455 patients randomly assigned to capecitabine received eight cycles, each lasting 21 days, at 1,250 mg/m2 twice a day for the first 14 days, followed by 7 days with no treatment.
The researchers found that, 2 years after starting the study, patients who were assigned to capecitabine had a 31% reduced risk of disease recurrence compared with those assigned to placebo. Disease-free survival was 87.3% for those assigned to capecitabine, and 80.5% for those assigned to placebo.
There was a nonsignificant tendency toward improved overall survival for those to assigned capecitabine; 2-year median overall survival was 96.2% vs 93.9%. Dr. Toi explained that these data are not yet mature, and it is possible that overall survival differences will become more pronounced as more time elapses.
Dr. Toi also noted that the researchers are conducting subset analyses to determine whether certain groups of patients benefited more than others from capecitabine. For example, they are looking at whether hormone-receptor status affected outcomes, he said. This study was supported by a grant from Specified Nonprofit Corporation–Advanced Clinical Research Organization (ACRO) and other donations to JBCRG. Dr. Toi has received a research grant from Chugai Pharmaceutical Company.
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