RT Journal Article SR Electronic T1 A Triple-negative Matrix-producing Breast Carcinoma Patient-derived Orthotopic Xenograft (PDOX) Mouse Model Is Sensitive to Bevacizumab and Vinorelbine, Regressed by Eribulin and Resistant to Olaparib JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 2509 OP 2514 DO 10.21873/anticanres.14221 VO 40 IS 5 A1 JUN YAMAMOTO A1 TAKUYA MURATA A1 YOSHIHIKO TASHIRO A1 TAKASHI HIGUCHI A1 NORIHIKO SUGISAWA A1 HIROTO NISHINO A1 SACHIKO INUBUSHI A1 YU SUN A1 HYEIN LIM A1 KENTARO MIYAKE A1 ATSUSHI HONGO A1 TSUNEHISA NOMURA A1 WATARU SAITOH A1 TAKUYA MORIYA A1 HIROKAZU TANINO A1 CHIHIRO HOZUMI A1 MICHAEL BOUVET A1 SHREE RAM SINGH A1 ITARU ENDO A1 ROBERT M. HOFFMAN YR 2020 UL http://ar.iiarjournals.org/content/40/5/2509.abstract AB Background/Aim: Matrix-producing breast carcinoma (MPBC) is a rare and usually aggressive triple-negative breast cancer (TNBC). In this study, we determined drug sensitivity for a triple-negative MPBC, without BRCA mutations, in a patient-derived orthotopic xenograft (PDOX) model. Materials and Methods: The MPBC PDOX model was established in the left 2nd mammary gland of nude mouse by implantation of the patient tumor using surgical orthotopic implantation (SOI). We randomized MPBC PDOX mice into 5 groups (n=5 mice/per treatment group) when the tumor volume reached 80 mm3: G1, control-no treatment; G2, bevacizumab [intra-peritoneal (i.p.), weekly, for 2 weeks]; G3, vinorelbine (i.p., weekly, for 2 weeks); G4, olaparib (oral., daily, for 2 weeks); G5, eribulin [intravenous (i.v.), weekly, for 2 weeks]. The mice in each treatment group were sacrificed on day 15. Tumor volume and body weight were measured once/week. Results: The MPBC PDOX model was resistant to olaparib (p=0.22). The MPBC PDOX model treated with bevacizumab and vinorelbine showed significantly suppressed tumor growth compared to the untreated group (p=0.005 and 0.002, respectively). However, only eribulin regressed the tumor (p=0.0001). Eribulin was more effective than olaparib (p=0.0001), bevacizumab (p=0.0025) and vinorelbine (p=0.0061). Conclusion: Eribulin has clinical potential as treatment for triple-negative MPBC patients that are resistant to a PARP inhibitor such as olaparib.