Comparison of the outcome of conventional osteosarcoma at two specialist international orthopaedic oncology centres.
OBJECTIVE
To determine the prognostic value of patient and treatment parameters in osteosarcoma, and whether these are equally important across international boundaries.


METHODS
Retrospective, cross-sectional study of 428 patients diagnosed with around-knee osteosarcoma, between 1990 and 1997 in Birmingham, UK, and Bologna, Italy. Disease-free survival (DFS) and overall survival (OS) assessed by Kaplan-Meier, Fisher's PLSD and Cox proportional hazard regression.


RESULTS
Five-year DFS and OS were 56 and 73% at Centre 1, compared to 43 and 60% at Centre 2 (P=0.0022 and P = 0.025, respectively). The most important bad prognostic factors for DFS and OS respectively were raised alkaline phosphatase at diagnosis (P=0.002 and P=0.003), tumour necrosis < 90% following chemotherapy (P=0.001 and P = 0.004) and volume > 150 cm(3) at diagnosis (P=0.04 and P=0.006). The most significant combination of bad prognostic factors was alkaline phosphatase and tumour necrosis. A total of 73% of patients at Centre 1 had greater than 90% necrosis of the tumour following neoadjuvant chemotherapy compared with 29% at Centre 2.


CONCLUSIONS
Tumour-based prognostic factors have similar significance across international boundaries. Chemotherapy effectiveness appears to be a major factor in explaining the survival difference between the two centres.
Ford
Samuel
S
Royal Orthopaedic Hospital Oncology Service Royal Orthopaedic Hospital Bristol Road South Birmingham B31 2AP UK.
Saithna
Adnan
A
Grimer
Robert J
RJ
Picci
Piero
P