Relationship between doxorubicin binding ability and tumor volume decreaseafter chemotherapy in adult malignant soft tissue tumors in the extremities

We have previously reported that the doxorubicin (DOX) binding ability dete cted by the DOX (or adriamycin) binding assay closely correlated with the c hemosensitivity of human osteosarcomas (1). We performed the present study to clarify the relationship between the DOX binding ability (%DB) and the h istologic response, rate of decrease in armor volume of malignant soft tiss ue tumors after preoperative chemotherapy and prognosis. Nine malignant sof t tissue tumors (4 liposarcomas, 3 synovial sarcomas, one malignant fibrous histiocytoma (MFH) and one extraskeletal osteosarcoma (EOS)) which arose a t the extremities of adult patients were analyzed by the DOX binding assay using freshly biopsied specimens. After preoperative chemotherapy including DOX or pirarubicin (THP), the rate of decrease in tumor volume was measure d using magnetic resonance imaging, and the histologic response expressed a s tumor necrosis to chemotherapy was also investigated. All the patients, a part for one, were continuously disease-free after treatment. One patient w ith EOS died of metastatic disease before surgery. The histologic response in 8 tumors without EOS was poor: The %DB of 5 tumors was greater than 80% (average: 95.90%), whereas that of 4 tumors was less than 80% (average: 38. 33%). Although there was no correlation between the %DB and the histologic response, or prognosis, a significantly positive can elation was found betw een the %DB and the rate of decrease in tumor volume (r = 0.7455, p< 0.05). These results suggest that in malignant soft tissue tumors, the rate of de crease in tumor volume after chemotherapy might be a better indicator for c hemosensitivity than the histologic response and also that the DOX binding ability might be a good predict for chemosensitivity before chemotherapy.