Impact of 3-year survival rate on treating IIB limb osteosarcoma patients with methotrexate plus DIA chemotherapy regimen

Abstract

Objecitve To evaluate the impact of adding methotrexate into DIA chemotherapy regimen (cisplatin, theraru-bicin and ifosfamide) on 3-year disease-free and overall survival of patients with IIB osteosarcoma in extremities. Methods Retro-spectively analyzed 34 cases of IIB limb osteosarcoma according to the Musculoskeletal Tumor Society (MSTS) surgical staging system with pathologically diagnosed concurrent chemotherapy and comprehensive surgical treatment from May 2008 to April 2014. There were 20 males and 14 females, with an average age of 19.5±7.7 years (ranged from 9 to 44 years). 28 patients underwent limb salvage surgery, and 6 patients received amputation. Tumor site included distal femur in 21 patients, proximal tibia in 9 patients, other sites in 4 patients. Seventeen patients underwent cisplatin, THP and ifosfamide (DIA) regimen of chemotherapy. The other 17 patients underwent cisplatin, THP, ifosfamide and methotrexate (MDIA) regimen. Patients charts were reviewed to get demographic data including age, gender, site, tumor size, surgery type, chemotherapy regimen, alkaline phosphatase, lactase dehydrogenase. The prognostic value of these factors on 3 years disease free survival and overall survival were calculated with Kaplan-Meier method and compared with Log-Rank test between different groups in univariate comparison and COX model for multivariate analysis was used to determine whether these demographic factors are independent prognostic factor for survival. Results Two patients had local recurrence, 7 patients had metastasis, and 2 patients had both local recurrence and metastasis. The 3-year survival of the whole group was 67.6% (23/34). Seven patients died during follow-up. The overall survival was 79.4% (27/34). The 3-year disease-free survival in DIA group and MDIA group was 70.6% (12/17) and 64.7% (11/17), respectively. The 3-year overall survival was 82.4% (14/17) and 76.5% (13/17) in DIA group and MDIA group, respectively. Univariate analysis showed that there was no significant difference in either 3-year disease-free survival (χ2=0.113, P=0.737) or overall survival (χ2=0.197, P=0.657) between DIA and MDIA. Age was significantly correlated with prognostic in univariate analysis (χ2=5.869, P=0.015), while gender, tumor site, tumor size, surgery type, ALP, LDH was not correlated with disease-free survival. Kaplan-meier analysis with Log-Rank test showed age (χ2=6.134, P=0.013) and tumor size (χ2=5.108, P=0.024) were statistically correlated with overall survival. Multivariate analysis with COX model showed that chemotherapy regimen was not an independent prognostic factor for 3-year disease-free survival or overall survival. Age was an independent prognostic factor for 3-year disease-free survival (HR=5.836, P=0.017). Conclusion The addition of MTX on the basis of DIA chemotherapy regimen did not significantly improve the 3-year disease-free survival and overall survival of stage IIB limb osteosarcoma. Key words: Osteosarcoma; Extremities; Antineoplastic combined chemotherapy protocols; Survival rate