7.P.32 PILOT STUDY RESULTS OF COMBINE HDMTX AND ADM/CDDP POLICHEMOTHERAPY TRIAL FOR OSTEOSARCOMA IN POLISH NATIONAL REFERENCE CENTER: SINGLE CENTER EXPERIENCE

Abstract

Tempting results of preliminary reports from EURAMOS-1 Study Group and our willingness to join the Consortium were the reason why we decided to start the pilot study exploit EURAMOS-1 protocol (approved by Local Ethical Commission).

Since November 2006, 41 patients were enrolled into study (20F/21M, mean age: 14, SD: 3,02) but 1 adolescent refused the treatment at all in 2nd week on. The main localization was thigh (20/41, 49%), followed by tibia (15/41, 37%), fibula (3/41, 7%) and humerus (3/41, 7%).

Majority of them had localized disease (27/41, 66%), whereas in 34% (14/41) lung metastases (LM) were revealed at diagnosis. Out of 40, 35 underwent surgery (2 amputations, 33 endoprosthesis) in 11th protocol week as average (mean: 12, SD: 2.80). Among the remaining 5 children, 4 progressed yet during neo-adjuvant CHT and 1 had to finish because of MTX intolerance. Up to now HP examination were completed in 29 children and the median of 12% of viable tumor cells remains (mean: 13%, SD: 22.32%; min. < 1%, max. 90%). Fourteen (48%) good responders continued on MAP arm. Children in whom poor HP response has been confirmed as well as all children with LM, received chemotherapy according to MAPIE arm. The switch between MAP and MAPIE proceeded in 18th week of protocol in average (median: 17th; nim. 14th, max. 24th week). Up to date, in 5 out of 21 patients completed the protocol, the treatment had to be finished untimely because of toxicity and further 5 required CHT switch because of progression.

Comparing achieved HP responses with previous experiences, we found no statistically significant differences in rate of tumor necrosis in current study (48%) as in previously used regimens (EORTC 49% and SFOP 44%; OR{EURAMOS/EORTC}=0.96; OR {EURAMOS/SFOP}=1.17; chi-square=0.343, p=0.842), but the general remarks from the pilot justify study’s continuation.