title: Metronomic chemotherapy for metastatic breast cancer to prolong time to treatment failure to 12 months or more.
abstract: The objective of treatment for metastatic breast cancer (MBC) is to control the disease or disease-related symptoms. Prolonged survival has also often been achieved by chemotherapeutic regimens in this setting. Long-term administration of one therapeutic regimen is essential for prolonging survival as well as for maintaining quality of life in these patients. In this study, we focused on time to treatment failure (TTF) as a parameter that predicts patient survival and we retrospectively compared clinical outcomes of patients with MBC who showed TTF of ≥12 months (26 patients) and <12 months (29 patients). The proportion of hormone receptor-positive tumors and the number of prior chemotherapy regimens for MBC were significantly higher and tumor grade was lower in patients with TTF ≥12 months compared to those with TTF <12 months. With regard to clinical outcomes, the objective response rate (ORR) in patients with TTF ≥12 months was significantly higher and median time to progression (TTP) and overall survival (OS) were longer compared to those with TTF <12 months. Of note, the proportion of patients who received metronomic regimens was significantly higher in patients with TTF ≥12 months compared to those with TTF <12 months (80.8 vs. 24.1%, P=0.00003). To assess the clinical benefit of metronomic regimens, the efficacy in patients receiving metronomic and those receiving non-metronomic regimens was compared. Although there was no difference in ORR between the two groups, median TTP and OS were significantly longer in the metronomic compared to the non-metronomic group (TTP: 30 vs. 4 months, P=0.0017; OS: 68 vs. 28 months, P=0.0005). The results suggested that metronomic chemotherapy is useful for palliative care and also improved clinical outcomes as a regimen for which long-term administration may be expected.
authors.affiliation: Department of Respiratory, Breast and Endocrine Surgery, Kagawa University Faculty of Medicine, Kagawa University Hospital, Kita-gun, Kagawa 761-0793;
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kontani
authors.affiliation: Department of Respiratory, Breast and Endocrine Surgery, Kagawa University Faculty of Medicine, Kagawa University Hospital, Kita-gun, Kagawa 761-0793;
authors.forename: Shin-Ichiro
authors.initials: SI
authors.lastname: Hashimoto
authors.affiliation: Department of Respiratory, Breast and Endocrine Surgery, Kagawa University Faculty of Medicine, Kagawa University Hospital, Kita-gun, Kagawa 761-0793;
authors.forename: Chisa
authors.initials: C
authors.lastname: Murazawa
authors.affiliation: Department of Surgery, Takamatsu Red Cross Hospital, Takamatsu, Kagawa 760-0017;
authors.forename: Shoko
authors.initials: S
authors.lastname: Norimura
authors.affiliation: Department of Pharmacy, Kagawa University Hospital, Kita-gun, Kagawa 761-0793;
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Kagawa Health Service Association, Health Care Center, Takamatsu, Kagawa 761-8071;
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohtani
authors.affiliation: Department of Radiology, Osaka Neurosurgery Hospital, Takamatsu 761-8083;
authors.forename: Naomi
authors.initials: N
authors.lastname: Fujiwara-Honjo
authors.affiliation: Department of Surgery, Date Hospital, Takamatsu, Kagawa 760-0076, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Date
authors.affiliation: Department of Pharmacy, Kagawa University Hospital, Kita-gun, Kagawa 761-0793;
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Houchi
authors.affiliation: Department of Respiratory, Breast and Endocrine Surgery, Kagawa University Faculty of Medicine, Kagawa University Hospital, Kita-gun, Kagawa 761-0793;
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Yokomise
keywords: metastatic breast cancer; metronomic chemotherapy; time to treatment failure