%0 Journal Article %A TSUTOMU TAKASHIMA %A TAKAHIRO NAKAYAMA %A KATSUHIDE YOSHIDOME %A HIDEMI KAWAJIRI %A SHUNJI KAMIGAKI %A JUNJI TSURUTANI %A TAKASHI ARAI %A TOSHIKAZU ITO %A YOSHIHUMI KOMOIKE %A TAKAKO DOI %A NORIKAZU MASUDA %A KEISUKE MIYAUCHI %A YASUO MIYOSHI %A JUNICHI SAKAMOTO %A SATOSHI MORITA %A TETSUYA TAGUCHI %T Phase II Study of S-1 in Combination with Trastuzumab for HER2-positive Metastatic Breast Cancer %D 2014 %J Anticancer Research %P 3583-3588 %V 34 %N 7 %X Aim: We undertook a prospective phase II study to evaluate the efficacy of S-1 plus trastuzumab combination regimen for human epidermal-growth factor receptor-2 (HER2)-positive metastatic breast cancer (MBC). Patients and Methods: HER2-positive MBC patients received oral administration of S-1 (80 mg/m2/day, days 1 to 28, every 6 weeks) and intravenous weekly trastuzumab (2 mg/kg), according to the results of a prior Phase I trial of our group. Results: A total of 28 patients were enrolled and received a median of 3.5 (range 1-10) cycles of treatment. Overall response rate and clinical benefit rate were 53.6% and 75.0%, respectively. Progression-free survival was 30 weeks. With regard to grade 3 and 4 adverse effects, leucopenia, neutropenia, increase in serum alanine aminotransferase, and diarrhea were observed. Conclusion: Combination of S-1 and trastuzumab was tolerable and had excellent efficacy with good response and disease control in this trial. %U https://ar.iiarjournals.org/content/anticanres/34/7/3583.full.pdf