Objective The purpose of this study was to assess the safety

Objective The purpose of this study was to assess the safety of S-1 in Japanese in inoperable or recurrent breast cancer patients. most common combination drug was trastuzumab. The overall incidence of adverse drug reactions was 63.5% (431/679 patients) in patients treated with S-1 alone and 55.9% (66/118 patients) in patients treated with S-1 + trastuzumab. Conclusions Monotherapy with S-1 or combination therapy with S-1 + trastuzumab was well tolerated for inoperable or Etomoxir recurrent breast cancer patients. Keywords: S-1 breast cancer post-marketing surveillance trastuzumab INTRODUCTION Breast cancer is currently curable if detected and treated early with a better prognosis than other cancers. However recurrent breast cancer is usually hard to remedy but can be treated to improve symptoms and quality of life and prolong survival time. S-1 is usually a formulation comprising tegafur (FT) a prodrug of 5-fluorouracil (5-FU) gimeracil (CDHP) which inhibits dihydropyrimidine dehydrogenase (a catabolic enzyme of 5-FU) and oteracil potassium (Oxo) which inhibits orotate phosphoribosyltransferase (a kinase for 5-FU) at a molar ratio of 1 1:0.4:1 (FT:CDHP:Oxo). It is currently utilized for the treatment of breast malignancy gastric malignancy colorectal cancer head and neck malignancy non-small cell lung malignancy pancreatic malignancy and biliary malignancy. S-1 is expected to be a therapeutic option that reduces the burden on patients because it can be administered orally on an outpatient basis thereby reducing the number of hospital visits (1 2 S-1 was approved for the treatment of inoperable or recurrent breast malignancy in 2005 and experienced a response rate of 41.7% in Etomoxir a Phase II study involving patients previously treated with a single regimen and 21.8% in another Phase II study involving patients who were unresponsive to taxanes (3 4 Trastuzumab is a humanized monoclonal antibody (4D5) designed to bind to the extracellular domain of human epidermal growth factor receptor 2 (HER2). The NCCN guidelines recommend trastuzumab either with or without chemotherapy as the first-line treatment for patients with HER2-overexpressing breast malignancy (5). Trastuzumab can be combined with fluoropyrimidines and the efficacy in combination with capecitabine has Rabbit Polyclonal to CA12. been reported (6). However the security of trastuzumab when used in combination with S-1 has not been studied in detail. Data from the current post-marketing surveillance of S-1 including Japanese patients with inoperable or recurrent breast malignancy are offered. The security of combined treatment with S-1 and trastuzumab was also evaluated in this article. PATIENTS AND METHODS Patients Patients with inoperable or recurrent breast cancer to be Etomoxir treated with S-1 for 2 years from January 2006 to December 2007 were included in the surveillance. Drug Administration S-1 was administered according to the ‘Dosage and Administration’ section of the package place: ‘A cycle consisting of repeated oral administration at an initial dose calculated from the body surface area twice daily (after breakfast and dinner) for 28 consecutive days followed by a 14-day washout period should be repeated’. After three cycles a survey form was collected and each item on the form was assessed. Survey Method A prospective post-marketing surveillance was performed at 313 sites in Japan from which approval of the director of the site was obtained and a contract was concluded. The prior registration form was faxed to the registration center through the central registration system no later than the first day of treatment. The survey items consisted of patient background treatment state concomitant medication/concurrent therapy clinical laboratory test and adverse events. As the key survey items the presence or absence of hand and foot syndrome at the start of TS-1 treatment and its onset in each course were surveyed. All adverse events that developed during three cycles of treatment with TS-1 were recorded around the case statement form and adverse events were Etomoxir recorded by the treating physician through interview and by laboratory tests. Adverse events were graded according to the Common.