A phase II trial of paclitaxel in patients with advanced soft tissue sarcomas. A Southwest Oncology Group study

The objectives of this Phase II trial of paclitaxel were to estimate the response rate and to define the toxicities of paclitaxel administered with recombinant granulocyte-colony stimulating factor in patients with advanced soft tissue sarcomas.

Patients were eligible if they had a histologic diagnosis of unresectable, recurrent or metastatic soft tissue sarcoma and had had no prior chemotherapy or radiotherapy. Paclitaxel at 250 mg/m2 was given by continuous intravenous infusion over 24 hours every 21 days. Doses were modified in subsequent courses based on nadir counts. Granulocyte-colony stimulating factor was given at 5 micrograms/kg subcutaneously days 3-18.

Forty-eight patients were treated; 1 patient had a complete response and 5 had partial responses for an overall response rate of 12.5% (95% confidence interval, 4.7%-25.3%). Thirty-eight of the 48 patients experienced grade 4 toxicities, with most of these life-threatening toxicities being hematologic. No deaths were attributed to therapy.

At the tested dose and schedule paclitaxel has antitumor activity approximating that of decarbazine in soft tissue sarcomas. Whether paclitaxel would be more effective administered in a longer infusion or with a chemosensitizer remains to be tested in this group of heterogeneous neoplasms.