422P Response rate and time to progression after first line chemotherapy with cisplatin and adriamycin in patients with metastatic osteosarcoma at presentation

Abstract

Metastatic osteosarcoma at presentation forms 10 to 20% of total osteosarcomas diagnosed. They have a very poor prognosis compared to non-metastatic subset. Patients with resectable metastasis have a better DFS and OS compared to unresectable metastatic disease at presentation. This study was done to find the response rate to first line cisplatin and adriamycin combination chemotherapy to upfront metastatic osteosarcoma patients and time to progression after first line chemotherapy. Secondary objective was to find the overall survival. Patients diagnosed with osteosarcoma at madras medical college were identified from the database for a period of 5.5 years from January 2013 to June 2018. From that patients who had metastasis at presentation were further sorted out and taken for analysis. 77 patients were diagnosed to have osteosarcoma during the 5.5year period. Among them 36 patients had metastatic disease at presentation. 28 patients were male (77.8%) and 8 patients were female (22.2%). Median age of the patients was 19.5 years. 23 patients had ECOG PS 2 (63.9%) and 12 had ECOG PS 1 (33.3%) and 1 had ECOG PS 3 (2.8%). Tibia and femur were the most common primary site (75%). 5 patients had resectable lung metastasis and underwent pulmonary metastasectomy and were excluded from analysis and 1 patient was on palliative care only. Among remaining 30 patients, 27 patients had multiple lung metastasis (90%) and 3 patients had bone metastasis (10%). 30 patients received 6 cycles of chemotherapy with adriamycin 25mg/m2 on d1-d3 and cisplatin 100mg/m2 on d1 repeated every 21 days except 3 who progressed during chemotherapy. 17 patients (56.7%) had grade 1-2 vomiting. No one developed any acute cardiotoxicity. No treatment related death occurred. At the end of 6 cycles, 22 patients (73.3%) had partial response and 5 patients (16.7%) had stable disease and 3 patients (10%) had progressive disease. Median time to progression was 11.5 months. 2year OS was 73.3%. This platinum doublet is a reasonable option for these patients as most of them are young.