Despite the fact that patients with TNBC had undergone adjuvant/neoadjuvant chemotherapy with an anthracycline and/or a taxane and were at high risk for relapse because of having a non-pCR or axillary lymph node metastases, TAT showed the completion rate that was comparable to those of the TS-1 studies in Japanese patients with gastric cancer or ER/PgR- and HER2-positive/negative breast caner. This evidence concerns the gene ESR1 and gastric cancer.