Taxane-based combinations as adjuvant chemotherapy for node-positive ER-positive breast cancer based on 2004-2009 data from the Breast Cancer Registry of the Japanese Breast Cancer Society.

BACKGROUND

Adding taxane to an anthracycline-based regimen improves survival in node-positive breast cancer patients, as shown by clinical trials and meta-analyses. However, no studies have analyzed the number of metastatic lymph nodes in patients with estrogen receptor (ER)-positive cancer. This study investigated whether adding a taxane to an anthracycline-based regimen improved prognosis in node-positive, ER-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients in a real-world setting.

METHODS

Using Japanese Breast Cancer Society registry data, we compared disease-free survival (DFS) of patients with ER-positive, HER2-negative breast cancer, excluding those receiving neoadjuvant chemotherapy, between those who received an anthracycline-based regimen followed by a taxane-based regimen (A + T) and those who received only an anthracycline-based regimen (A w/o T), stratified by lymph node status. A Cox proportional hazards model was used to evaluate DFS in both groups.

RESULTS

There were 4566 eligible patients with ER-positive, HER2-negative breast cancer. During the median follow-up period of 60 months, there were 481 recurrences and 149 deaths. There was no significant difference in DFS between the A + T and A w/o T groups among patients with 1-3 positive nodes, while there was a significant difference among patients with ≥ 4 positive nodes.

CONCLUSIONS

In patients with ER-positive, HER2-negative breast cancer, adding taxane to an anthracycline regimen did not improve DFS in patients with metastasis in 1-3 lymph nodes. We considered that the group without the addition of taxane might be present in patients with ER-positive, HER2-negative lymph node metastases.