Clinical Analysis of Osteosarcoma Patients Treated with High-Dose Methotrexate-Free Neoadjuvant Chemotherapy

(1) Objective: High-dose methotrexate (hdmtx) is a common therapeutic agent in the treatment of osteosarcoma. However, hdmtx is highly toxic and requires complex pharmacokinetic monitoring and leucovorin rescue. Thus, alternative therapeutic strategies are necessary. Here, we analyzed the clinical efficacy of a dia regimen (cisplatin–ifosfamide–doxorubicin) to evaluate its potential as an alternative to hdmtx–based therapy. (2) Methods: Patients received 12 cycles of chemotherapy administered over 2 years (2 preoperative cycles and 10 postoperative cycles). Cumulative dose was the same in all cycles: cisplatin 120 mg/m² on day 1 of week 1, followed by ifosfamide 2.0 g/m² days 1–5 of week 2, and doxorubicin 20 mg/m² days 1–3 of week 2. (3) Results: Between January 2004 and October 2008, 39 eligible patients (median age: 16 years) were enrolled, with 36 being evaluable for the study. Of those 36 patients, 20 (55.6%) had a good histologic response to preoperative chemotherapy (>90% tumour necrosis). The estimated 5-year rates of event-free survival (efs) and overall survival were 54.8% and 61.5% respectively. (4) Conclusions: The results of our study suggest that, in osteosarcoma patients, the dia regimen produces an efs rate and survival outcomes comparable to those attained with hdmtx–containing regimens, with fewer adverse reactions. The dia regimen is well tolerated, and we observed a high level of patient compliance. Our results demonstrate that hdmtx-free osteosarcoma treatment regimens can be effective, warranting further investigation.