title: Collagen gel droplet-embedded culture-drug sensitivity test and Ki67 expression in estrogen receptor-positive and HER2-negative breast cancer.
abstract: Anthracyclines and taxanes are standard anticancer drugs used in breast cancer chemotherapy. In general, the efficacy of chemotherapy is lower in patients with estrogen receptor (ER)-positive tumors compared to patients with ER-negative tumors. Although less chemosensitive, ER-positive disease includes a subset of patients who significantly benefit from adjuvant chemotherapy. The collagen gel droplet-embedded culture-drug sensitivity test (CD-DST) is anin vitrochemosensitivity test that has several advantages over conventional tests. The aim of the present study was to examine the correlation between CD-DST and the expression of Ki67, an indicator of tumor proliferation, to evaluate the efficacy of anthracyclines and taxanes in patients with ER-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. CD-DST was performed in 68 patients with ER-positive and HER2-negative breast cancer between August 2001 and November 2006. The specimens obtained during surgery were used for the CD-DST and immunohistological examination of Ki67 expression. Chemosensitivity to the anticancer drugs adriamycin (ADM), epirubicin (EPI), docetaxel (DOC) and paclitaxel (PTX) was estimated using CD-DST. Results obtained from the CD-DST showed the chemosensitivity to each anticancer drug to be ADM, 23.7%; EPI, 75.0%; DOC, 69.2% and PTX, 43.6%. Ki67 expression was significantly higher in the group that was sensitive to DOC compared to the group that was resistant to DOC (P=0.048) and PTX (P=0.036). In addition, a significant correlation was observed between a Ki67 labeling index (LI) of >30% and chemosensitivity to PTX. In conclusion, results obtained from CD-DST and Ki67 expression levels are able to identify a subset of patients with ER-positive and HER2-negative breast cancer who exhibit sensitivity to chemotherapy, particularly to taxane therapy.
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Katsunori
authors.initials: K
authors.lastname: Tozuka
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Jun
authors.initials: J
authors.lastname: Horiguchi
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takata
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Nana
authors.initials: N
authors.lastname: Rokutanda
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Rin
authors.initials: R
authors.lastname: Nagaoka
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tokiniwa
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Mami
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Ayako
authors.initials: A
authors.lastname: Satou
authors.affiliation: Division of Breast Surgery, Saitama Cancer Center, Kitaadachi, Saitama 362-0806, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takei
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511;
authors.forename: Izumi
authors.initials: I
authors.lastname: Takeyoshi
keywords: Ki67; breast cancer; chemotherapy; collagen gel droplet-embedded culture-drug sensitivity test; estrogen receptor