Gemcitabine-Based Chemotherapy for Advanced Soft Tissue Sarcoma: Identifying the Appropriate Dose and Schedule

Background In 2024, reimbursement for gemcitabine-docetaxel therapy (GEM-DOC; gemcitabine 900 mg/m² on days 1 and 8 and docetaxel 70 mg/m² on day 8 every 21 days, GEM 900-DOC 70) to treat recurrent/metastatic soft tissue sarcoma (STS) was made in Japan. Methods We retrospectively reviewed clinical records of advanced/metastatic STS patients who underwent off-label gemcitabine-containing chemotherapy at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research between February 2007 and October 2019. Results Of 115 enrolled patients, 51 were treated with GEM-DOC (26 patients received the dose as previously stated) and the other 64 with gemcitabine monotherapy. Objective response rates (ORR; 9.8% versus 4.7%), progression-free survival (PFS; 3.8 months versus 2.1 months), and overall survival (OS; 21.5 months versus 11.8 months) tended to be superior in GEM-DOC; the difference of the rate of following salvage treatment (GEM-DOC, 82.4%; gemcitabine monotherapy, 48.4%) could affect the OS. As for safety, severe adverse events (grade 3 {G3} or more) were more frequent in patients with GEM-DOC (hematologic, 80.4% versus 40.6%; non-hematologic, 19.6% versus 15.6%), including those using the stated dose (hematologic, 96.1%; non-hematologic, 26.9%). Conclusion The stated dose of GEM-DOC could be effective for STS but shows more toxicity compared to other dose settings or gemcitabine monotherapy. An investigation of appropriate dose settings by prospective clinical trial may be needed.