Establishment of Biobank and Patient-Derived Xenograft of Soft Tissue and Bone Tumors

Soft tissue and bone tumors are rare, and their low frequency and diverse histological types make conducting large-scale clinical trials challenging. Patient-derived xenografts (PDX), entailing implantation of cancer specimens in immunocompromised mice, are emerging as a valuable translational model because PDX keeps the original tumors' character and drug sensitivity. We sequentially transplanted 166 surgical and biopsy specimens from orthopedic surgeries, including 138 soft tissue and bone tumors (81 malignant, 23 intermediate, and 34 benign), 16 metastatic bone tumors, 9 hematological malignancies, and 3 non-tumor tissues. Every specimen was cutaneously transplanted into both flanks of BALB/c Rag-2/Jak3 double deficient (BRJ) mice, and tumor formation was observed for up to 6 months. We defined PDX models as successfully generated if the tumors were passaged more than three times while retaining the histological characteristics of the original tumor. The rates of PDX generation were 28.1% (39/138) for all soft tissue and bone tumors, 42.6% (35/81) for malignant tumors, 4.3% (1/23) for intermediate tumors, and 8.8% (3/34) for benign tumors. Our models of PDX would be a useful platform for soft tissue and bone tumor precision medicine.