Comparison of pemetrexed plus cisplatin with gemcitabine plus docetaxel in refractory/metastatic osteosarcoma: Clinical outcomes from a retrospective database monitored in a single institute

The prognosis for patients with relapsed/metastatic osteosarcoma is poor and the optimal treatment strategy remains to be refined. Whilst gemcitabine plus docetaxel combination treatment has already been demonstrated to have certain promising results in the treatment of osteosarcoma, the use of pemetrexed, a multi-targeted antifolate, remains controversial. In the present study, a retrospective investigation was conducted to evaluate the toxicity and efficacy of the pemetrexed plus cisplatin combination in relapsed/metastatic osteosarcoma. Comparison of this treatment with that of the gemcitabine plus docetaxel combination was also conducted. Clinical data from 39 patients suffering from refractory/metastatic osteosarcoma between January 2005 and May 2011 were reviewed retrospectively. Of these patients, 21 were administered the gemcitabine plus docetaxel combination, and 18 were provided the pemetrexed plus cisplatin combination. Treatment was continued until the occurrence of disease progression or unacceptable toxicity. In the gemcitabine plus docetaxel group, the overall response rate and disease control rate were found to be 9.5 and 28.5% respectively, compared with 5.5 and 33.3% respectively in the pemetrexed plus cisplatin group. The median progression-free survival (PFS) time was found to be 1.8 months for both the gemcitabine plus docetaxel and pemetrexed plus cisplatin groups. The median overall survival (OS) time was 6 months in the gemcitabine plus docetaxel group and 7 months in the pemetrexed plus cisplatin group. No statistically significant differences were recognized between the overall response rates, disease control rates, PFS times and OS times in the two groups. The two combinations appeared to be well tolerated. However, the incidence of grade 3/4 thrombocytopenia and leucopenia was higher in the gemcitabine plus docetaxel group than in the pemetrexed plus cisplatin group. The present study clearly demonstrated that both chemo-combinations were well-tolerated and exerted antitumor activity in patients with refractory/metastatic osteosarcoma. However, with regard to grade 3/4 toxicity, the pemetrexed plus cisplatin chemotherapy appears to be better tolerated.