Results of methotrexate-etoposide-ifosfamide based regimen (M-EI) in osteosarcoma patients included in the French OS2006/sarcome-09 study
The article reports the outcome of patients with osteosarcoma, treated in the French OS2006 study with methotrexate, etoposide, ifosfamide pre-operatively and risk adapted chemotherapy post-operatively (M-EI for good responders, M-AP for poor responders). OS2006 was a randomized trial, exploring the effect of zoledronate on survival. The results of the randomization have previously been reported. The group now reports the survival and safety of the total study population.
The French group has previously compared methotrexate/doxorubicin to methotrexate/etoposide-ifosfamide pre-operatively. Given the comparable efficacy, M-EI has become standard of care in France. Post-operatively, patients who are high-risk (either poor responders, metastatic or unresectable) receive MAP, while low-risk patients receive M-EI. This paper reports survival results on the study population of OS2006, including patients who had refused the randomization.
Only 134/374 patients received post-operative treatment as per protocol (89/221 standard-risk patients and 45/153 high-risk). In the study population, 213/409 patients, including 187/324 with localized disease, received neither doxorubicin nor cisplatin first-line treatment (pre- or postoperatively). Median follow up was 4.8 years. The 3- and 5-year EFS were 63% (95% CI, 58-68%) and 56% (95% CI, 51-62%), respectively. The 3- and 5-year OS were 81% (77-85%) and 71% (66-76%), respectively.
The authors suggest that the chemotherapy protocol proposed had the same efficacy as MAP, but with more limited long-term side effects. Unfortunately, this is not a randomized trial and there is no comparison group, so it is not adequate to answer the question. Also, a high proportion of cases was given chemotherapy not according to the protocol. While these results are promising, the role of EI in osteosarcoma treatment remains to be clarified.