title: Clinical implication of Time To Brain Metastasis (TTBM) according to breast cancer subtypes.
abstract: The aims of the present study were to investigate how breast cancer (BC) subtypes and treatment affect time to brain metastasis (TTBM). We retrospectively investigated 189 consecutive patients who were diagnosed with brain metastasis (BM) from BC between 2000 and 2009 at Samsung Medical Center. We analyzed TTBM from initial diagnosis of metastatic BC according to subtypes and trastzumab (T) administration before BM diagnosis. The median age of 189 BM patients from BC was 48 years. We divided TTBM into four groups considering BC subtypes and treatment; HR-positive/HER2-negative (n=45), HER2-positive with T before BM development (n=47), HER2-positive without T before BM development (n=39), and TNBC (n=58). The median TTBMs for each group were 17.5 months, 13.7 months, 5.8 months, and 2.9 months, respectively (p<0.001). HER2-positive without T (HR 1.892, p=0.008) and TNBC (HR 1.652, p=0.023) were independently associated with shorter TTBM. In multivariate analysis, HER2-positive without T (hazard ratio 1.725, p=0.002) and TNBC (hazard ratio 1.579, p=0.022) were independent risk factors for worse metastatic OS compared with HR-positive/HER2-negative subtype. TTBMs were shorter in patients with HER2-positive without T and TNBC among BC subtypes. Prospective clinical study for high risk patients for early BM is warranted.
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Ahn
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Park
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Silvia
authors.initials: S
authors.lastname: Park
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Chi Hoon
authors.initials: CH
authors.lastname: Maeng
authors.affiliation: Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Park
authors.affiliation: Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Doo Ho
authors.initials: DH
authors.lastname: Choi
authors.affiliation: Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Hur
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Ahn
authors.affiliation: Division of Hematology-Oncology, Department of Medicine Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu Seoul, 135-710 South Korea.
authors.forename: Young-Hyuck
authors.initials: YH
authors.lastname: Im
keywords: Brain metastases; Breast cancer; HER2; Trastuzumab; Triple negative