Prognostic stratification of patients with non-metastatic osteosarcoma may improve the clinical management and the design of clinical trials.

Data from 773 patients [median age 15 years (3-40)] treated at our Institute from 1983 to 2000 with high-dose methotrexate, cisplatin, doxorubicin and ifosfamide (neoadjuvant chemotherapy) were analyzed. After multivariate analysis including age, site, tumour volume (cut-off 200 mL), serum LDH and Alkaline Phosphatase (SAP), histology (osteoblastic and chondroblastic vs others), high LDH and SAP, osteoblastic and chondroblastic histotypes resulted independent prognostic factors of DFS.

Patients were grouped according to a score from 0 (absence) to 3 (one to 3 adverse factors). The scoring system was implemented by the addition of PgP expression and grade of chemotherapy-induced necrosis.

A score of 0, 1, 2, 3 was given to 14%, 38%, 32% and 16% of patients respectively.10-year DFS was 80% (95%CI 72-89) for score of 0, 58% (95%CI 52-64) for 1, 53% (95%CI 46-59) for 2 and 40% (95%CI 32-50) for 3 (p= 0.001). PgP expression (168 patients) identified patients with 100% probability of DFS (score of 0 and negative PgP) and patients with 18% (95%CI 52-64) DFS (score of 3 and positive PgP).

Good (GR) and poor responder (PR) patients had the same probability of DFS in case of score of 0 [GR82% (95% CI 72-91), PR79% (95% CI 65-93)] and score of 3 [GR43% (95% CI 32-55) PR36% (95% CI 21-51)]. Different probability of DFS in case of score of 1 [GR64% (95% CI 57-72) PR47% (95% CI 36-59)] and score of 2 [GR63% (95% CI 55-71) PR36% (95% CI 21-51)].

It is possible to stratify outcomes of patients with non metastatic osteosarcoma of the extremity by means of a simple score based on easily available clinical parameters. This scoring system is worth to be validated on larger series.

Between 1986 and 2002, 42 patients with synchronous multifocal osteosarcoma were treated with two different protocols of neoadjuvant chemotherapy. When feasible, the primary and secondary tumours were excised as a combined procedure.

After initial chemotherapy 26 patients were excluded from simultaneous excision of all their secondary bone lesions as their disease was too advanced. In 12 patients only isolated excision of the primary lesion was possible. For 16 patients simultaneous operations were conducted to excise the primary and secondary lesions. This involved two supplementary sites in 15 patients and four additional sites in one patient. Of these, 15 attained remission but 12 relapsed and died (11 within two years). Three patients remained disease-free at five, six and 17 years. The histological response to pre-operative chemotherapy of the primary and secondary lesions was concordant in 13 of the 16 patients who underwent simultaneous operations at more than one site.

The prognosis for synchronous multifocal osteosarcoma remains poor despite combined chemotherapy and surgery. The homogeneous histological responses in a large proportion of the primary and secondary lesions implies that synchronous multifocal osteosarcoma tumours are not multicentric in origin, but probably represent bone-to-bone metastases from a single tumour.