|May P-glycoprotein status be used to stratify high-grade osteosarcoma patients? Results from the Italian/Scandinavian Sarcoma Group 1 treatment protocol|
Authors: Massimo Serra, Michela Pasello, Maria Cristina Manara, Katia Scotlandi, Stefano Ferrari, Franco Bertoni, Mario Mercuri, Thor Andreas Alvegard, Piero Picci, Gaetano Bacci, Sigbjørn Smeland
Laboratorio di Ricerca Oncologica, Istituti Ortopedici Rizzoli, 40136 Bologna, Italy. email@example.com
The aim was to evaluate the clinical impact of P-glycoprotein in primary non-metastatic high-grade osteosarcoma patients, treated with neoadjuvant chemotherapy protocols. P-glycoprotein was assessed by immunohistochemistry on paraffin-embedded tissue samples collected at time of diagnosis from 94 osteosarcoma patients, treated with the Italian Sarcoma Group/Scandinavian Sarcoma Group 1 (ISG/SSG 1) protocol. P-glycoprotein-positivity at diagnosis was found in 53/94 ISG/SSG 1 cases (56%) and emerged as the single factor significantly associated with an unfavourable outcome from survival and multivariate analyses. A comparative analysis of the subgroup of 94 patients considered for P-glycoprotein evaluation and the whole series of ISG/SSG 1 patients showed that this marker retained its prognostic value also in the latter group. In osteosarcoma patients treated with doxorubicin-based chemotherapy protocols, P-glycoprotein overexpression at diagnosis is an important adverse prognostic factor for outcome. P-glycoprotein evaluation can therefore constitute the basis for stratifying, at diagnosis, osteosarcoma patients for whom alternative treatments may be considered.