Ten patients (33.3%) did not receive another line of treatment after the first therapy following T-DM1. Open in a separate window Figure 1 Flow chart of the study design. and focused on the population that received another line of therapy following T-DM1 discontinuation. Thirty patients were available for the outcome analysis. Median progression-free survival (PFS) of the first subsequent therapy was 6.0 months [95% confidence interval (95% CI) 4.1C6.4], whereas the median overall survival (OS) from your first subsequent therapy was 20.6 months (95% CI 13.5 months to not CID 1375606 reached). We divided the patients into 2 groups according to their PFS with T-DM1 treatment and compared their PFS with the subsequent therapy. The results revealed a significant difference in the median PFS with the first subsequent treatment CID 1375606 between patients with the PFS of less than and more than 3 months [5.1 (95% CI 1.7C6.2) vs 6.2 (95% CI 4.0C11.3) months, values were 2-sided, and a value of .05 was considered to indicate significance. All statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University), a graphical user interface for R (the R Foundation for Statistical Computing, version 3.4.1). More precisely, it is a modified version of R commander (version 2.4-1) that is designed to add frequently used statistical functions in biostatistics. 3.?Results 3.1. Patient characteristics Sixty-six patients with HER-2 positive MBC were administered T-DM1 between April 1, 2014, and December 31, 2018, at the NCCH. Sixty-one patients who discontinued the T-DM1 therapy, 11 patients who were enrolled in a clinical trial after T-DM1 treatment, and 1 patient with occult primary cancer were excluded from the study. Seventeen patients did not receive another line of therapy following T-DM1, including those lost to follow-up. Two patients were excluded because of incomplete data for analysis. Finally, 30 patients who received a therapy after T-DM1 discontinuation (ie, until March 31, 2019) were analyzed in this study (Fig. ?(Fig.1).1). The baseline characteristics of the study population at the start of the first therapy following T-DM1 treatment are presented in Table ?Table1.1. The median age was 56 (30C80) years, and 29 patients (96.6%) had PS 0 to 1 1. At the initial diagnosis, 22 patients (73.3%) had stage I-III disease, and 8 patients (26.7%) had distant disease; 22 patients (73.3%) had ER and/or PgR-positive disease. Eighteen (60.0%) patients received Rabbit Polyclonal to 5-HT-1F neoadjuvant or adjuvant chemotherapy, 12 patients (40.0%) received adjuvant endocrine therapy, and 11 patients (36.7%) were exposed to Tmab in a neoadjuvant and/or adjuvant setting. Twenty-six patients (86.7%) had visceral disease, which was defined as a disorder of the lung, pleura, brain, liver, pancreas, duodenum, or adrenal gland. The median number of prior chemotherapy regimens for metastatic disease before the subsequent therapy was 2 (range 1C7). Furthermore, 13 (43.3%) patients received Pmab (Table ?(Table1).1). Eribulin monotherapy CID 1375606 was the most common first subsequent therapy (33.3%) (Table ?(Table2).2). Thirteen (43.3%) patients received a regimen containing Tmab and/or lapatinib as the first therapy following T-DM1 treatment CID 1375606 (Table ?(Table2).2). Ten patients (33.3%) did not receive another line of treatment after the first therapy following T-DM1. Open in a separate window Figure 1 Flow chart of the study design. Sixty-six patients with HER-2 positive metastatic breast cancer were administered T-DM1 and 30 patients who received a therapy after T-DM1 were included in our analysis. HER2?=?human epidermal growth factor 2, T-DM1?=?trastuzumab emtansine. Table 1 Characteristics of the study population (n?=?30). Open in a separate window Table 2 Chemotherapies administered after T-DM1 discontinuation. Open in a separate window 3.2. Survival outcomes and efficacy The median follow-up period was 21.8 months. The median PFS and median OS due to T-DM1 were 3.7 months (95% CI 2.7C5.5) and 28.9 months (95% CI 18.3 months to not reached), respectively (Supplementary Fig. 1a and 1b). The best overall response to T-DM1 (n?=?30) was as follows: 2 patients (6.7%) showed a partial response (PR), 16 (53.3%) showed a stable disease (SD), and 12 (40%) showed a PD. The median PFS with the first subsequent therapy was 6.0 (95% CI 4.1C6.4) months (Fig. ?(Fig.2A),2A), whereas the median OS from the initial administration of the first subsequent therapy was 20.6 (95% CI 13.5 months to not reached) (Fig. ?(Fig.2B).2B). The best overall response to the first subsequent therapy (n?=?30) was as follows: 1 patient (3.3%) showed a complete response, 12 (40%) showed a PR, 11 (36.7%) showed a SD, and 6 (20%) showed a PD. The objective responses of patients for the measurable target lesion are graphically presented in Figure ?Figure33 (n?=?28). As shown in Figure ?Figure3,3, the response rates tended to be higher in the group that received anti-HER2 drugs as the first therapy after T-DM1 than in the group that did not receive (Supplemental Table 1). Open in a separate window Figure 2 (A) Progression-free survival of.