Nine-weeks of adjuvant trastuzumab in HER2-positive breast cancer: A single center experience.

Abstract

e11080 Background: Trastuzumab is an effective adjuvant targeted therapy in patients with HER-2 positive breast cancer. However, effect of this therapy on survival is not well described in literature. In this study, we aimed to show characteristics of patients treated with nine week trastuzumab therapy for breast cancer and survival analysis. Methods: We analyzed the data of 2.218 breast cancer patients treated and followed up in our medical oncology department. There were 165 patients treated with 9 weeks of adjuvant trastuzumab therapy in this cohort. Patients’ characteristics, prognostic factors, and survival data were analyzed by using SPSS 18.0 version. Results: The mean age of the patients at the time of diagnosis of breast cancer was 47.3 ± 10.0 years. Sixty two (37.6%) patients were postmenopausal, eighty two patients (49.7%) were premenopausal and twenty patients (12.1%) were peri-menopausal. Invasive ductal carcinoma was the most common pathological type and was observed in 87.9% of the patients. ER and PR was positive in 49.1% of the patients and 54.5 % of the patients, respectively. Percentage of stage of the patients was 10.9 in stage I, 21.1 in stage IIA, 17.6 in stage IIB, 21.2 in stage IIIA, 0.6 in stage IIIB, 23.6 in stage IIIC. Mean follow up time of the patients was 30.9 ± 13.4 months. Numbers of the patients with progression were eighteen (10.9%). Eight (4.8%) patients died due to disease progression. Two-year survival rate was 98.3%. Disease free, progression free and overall survival times could not be obtained due to inadequate number of events. Conclusions: The superiority of nine weeks of adjuvant trastuzumab therapy to standard one year regimen of adjuvant trastuzumab is not well described in literature. The studies comparing 9-weeks and one year of adjuvant trastuzumab use with large numbers of patients are needed to show which regimen is superior.