RT Journal Article SR Electronic T1 Osteosarcoma of the Breast in a Patient Derived Orthotopic Xenograft (PDOX) Mouse Model Is Arrested by both Cisplatinum and Eribulin JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 3107 OP 3110 DO 10.21873/invivo.12605 VO 35 IS 6 A1 NORIYUKI MASAKI A1 NATHANIEL F. WU A1 YUSUKE AOKI A1 JUN YAMAMOTO A1 JUN MIYAZAKI A1 ROBERT M. HOFFMAN YR 2021 UL http://iv.iiarjournals.org/content/35/6/3107.abstract AB Background/Aim: Primary osteosarcoma of the mammary gland is a very rare disease, accounting for less than 1% of all mammary malignancies. There is no established first-line treatment and the prognosis is poor compared to normal breast cancer. We previously established the first patient tumor-derived animal model of this disease, grown subcutaneously in nude mice. In the present study, we established a patient derived orthotopic xenograft (PDOX) model of osteosarcoma of the breast and investigated the efficacy of cisplatinum (CDDP) and eribulin (ERB). Materials and Methods: PDOX models of primary osteosarcoma of the breast were divided into 3 groups (5-6 mice per group): untreated control; CDDP treatment; ERB treatment. The tumor volume in the 3 groups was compared after 2 weeks. Results: There were significant differences between control and CDDP, and control and ERB (p=0.036, 0.046, respectively). However, there was no significant difference between CDDP and ERB (p=0.964). Conclusion: CDDP and ERB are candidates for first-line clinical therapy of primary osteosarcoma of the breast.