Clinical Progression on Neoadjuvant Chemotherapy: An Indicator of Poor Outcomes in Extremity Osteosarcoma.

Osteosarcoma is a matrix-producing neoplasm. Most patients are treated with neoadjuvant chemotherapy (NACT. Various parameters are available for response assessment which include radiological and histological criteria. Data on clinical responses such as pain response and size assessment is meagre. In this study, we aimed to analyze if clinical assessment used for response evaluation can predict prognosis in patients receiving neoadjuvant chemotherapy for extremity osteosarcoma. All patients diagnosed with osteosarcoma and who underwent treatment with curative intent between January 2000 and December 2018 were identified. Patients who had progression were identified and whether clinical progression impacted overall survival (OS) and disease-free survival (DFS) was analyzed. Forty-three patients who had progression on NACT were identified. When compared to patients who did not have clinical progression, more patients in the clinical progression group had large tumors (p = 0.025), the majority underwent amputation (p = <0.001), and most were poor responders to chemotherapy (p = 0.011). Clinical progression on NACT predicted poor OS and DFS on univariate analysis but not on multivariate analysis. Although patients with clinical progression had poor oncological outcomes, it was not a statistically significant factor affecting oncological outcomes. The role of continuing the same chemotherapy regimen in the adjuvant setting in this subset of patients is doubtful. Large multicentric studies are needed to know the prognostic impact of clinical progression during NACT on oncological outcomes.