Abstract 1648P
Background
Metastatic osteosarcoma at presentation constitutes 10 to 20% of total osteosarcomas diagnosed. They have a very poor prognosis compared to non-metastatic subsets. This study was performed to find the response rate to first line cisplatin and adriamycin combination chemotherapy in upfront metastatic osteosarcoma patients and time to progression after first line chemotherapy. Secondary objective was to measure the overall survival (OS).
Methods
Patients diagnosed with osteosarcoma at Madras Medical College were retrospectively identified from January 2013 to December 2017 (5 years). From these patients, those who had metastases at presentation were identified and analysed.
Results
71 patients were diagnosed with osteosarcoma during the 5 year period. Among them, 32 patients (45.1%) had metastatic disease at presentation. 25 patients were male (78.1%) and 7 were female (21.9%). Median age of the patients was 20.5 years. Two patients had type 2 diabetes mellitus; 20 patients had ECOG PS 2 (62.5%) and 12 had ECOG PS 1 (37.5%). Tibia and femur were the most common primary site (71.9%). 5 patients had resectable lung metastasis and underwent pulmonary metastasectomy and were excluded from analysis. Among the remaining 27 patients, 24 had multiple lung metastases (88.9%) and 3 had bone metastases (11.1%). All patients received 6 cycles of chemotherapy with adriamycin 25mg/m2 on d1-d3 and cisplatin 100mg/m2 on d1 repeated every 21 days, except 2 who progressed during chemotherapy. 15 patients (55.6%) had grade 1-2 vomiting. No one developed any acute cardiotoxicity and no treatment-related deaths occurred. At the end of 6 cycles, 20 patients (74.1%) had partial response, 5 patients (18.5%) had stable disease and 2 patients (7.4%) had progressive disease. Median time to progression was 12 months; 2-year OS was 77.8%.
Conclusions
Metastatic osteosarcoma has a very poor prognosis overall. This platinum doublet is a reasonable option for these patients as most of them are young. A larger randomized controlled trial will be needed to understand response to different chemotherapy regimens in this metastatic subset.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Sivasubramaniam Kumaravelu.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.