Prognosticating metastatic osteosarcoma treated with uniform chemotherapy protocol without high dose methotrexate and delayed metastasectomy: a single center experience of 102 patients

Abstract

Purpose: Data on prognostic factors in patients with metastatic osteosarcoma treated with uniform chemotherapy protocol are lacking. The objective of this study was to analyze demographic data, treatment outcome and prognostic factors for patients with metastatic osteosarcoma at our center treated with a uniform chemotherapy protocol without high dose methotrexate.

Methods: This is a single-institutional data review of patients treated between June 2003 and December 2012 with neoadjuvant chemotherapy, local site surgery followed by adjuvant chemotherapy and metastasectomy at completion of adjuvant chemotherapy.

Results: 102 patients of metastatic osteosarcoma were treated with a median age of 18 years (range 8-48 years), male to female ratio of 3.3:1 and median symptom duration of 4 months. EFS and OS at 5 years were 12.7 ± 0.1 and 28.1 ± 0.1 %, respectively. On multivariate analysis, elevated serum alkaline phosphatase (p < 0.001) and number of metastasis >3 (p = 0.04) were predictive of lower EFS, whereas elevated serum alkaline phosphatase (p = 0.01), number of metastasis >3 (p = 0.05), and margin positivity (p < 0.001) were predictive of lower OS.

Conclusions: This is the largest data on metastatic osteosarcoma treated with a uniform chemotherapy protocol without high dose methotrexate. The data showed prognostic factors similar to what have been observed previously such as elevated serum alkaline phosphatase and >3 metastatic lesions in lung predicting inferior outcome. Notably our survival was comparable to data from other studies despite our practice of delaying metastasectomy to completion of chemotherapy rather than performing the same along with local site surgery.

Keywords: Delayed metastasectomy; Metastatic osteosarcoma; Without high dose methotrexate.