Table 1.
Clinical characteristics
| Median age in years (range) | 13.8 (2.4 – 17.9) |
| Number of children aged < 12 years (%) | 109 (32.3) |
| Number of adolescents aged ≥ 12 years (%) | 228 (67.7) |
| Gender | |
| Number of males (%) | 222 (65.8) |
| Number of females (%) | 115 (34.1) |
| Median duration of symptoms in months (range) | 3 (1 – 12) |
| Tumour size at presentation | |
| ≥ 8 cm, n (%) | 302 (89.6) |
| < 8 cm, n (%) | 35 (10.4) |
| Histopathologic subtype, n (%) | |
| Osteogenic | 273 (81) |
| Chondroblastic | 47 (13.9) |
| Telengiectatic | 6 (1.8) |
| Not specified | 10 (2.9) |
| Parosteal | 1 (0.3) |
| Primary tumour site, n (%) | |
| Lower extremity | 286 (84.9) |
| Upper extremity | 42 (12.7) |
| Cranial | 6 (1.8) |
| Thorax | 2 (0.6) |
| Spine | 1 (0.3) |
| Baseline stage, n (%) | |
| Localized | 295 (87.5) |
| Metastatic | 42 (12.5) |
| Lung metastases | 39 (11.6) |
| Bone metastases | 3 (0.9) |
| Surgery type (n = 253) | |
| Amputation, n (%) | 193 (76.3) |
| Limb salvage, n (%) | 60 (23.7) |
| Bone autograft | 13 (5.1) |
| Frozen bone autograft | 9 (3.6) |
| Mega-prosthesis | 31 (12.3) |
| Vascularized bone autograft | 7 (2.8) |
| Histopathologic necrosis (n = 241) | |
| < 90%, n (%) | 132 (54.8) |
| ≥ 90%, n (%) | 109 (45.2) |
| Surgical margins (n = 261) | |
| Negative, n (%) | 250 (95.8) |
| Close, n (%) | 10 (3.8) |
| Positive, n (%) | 1 (0.4) |
Figure 1.
Kaplan-Meier survival curves for osteosarcoma (A) overall survival, (B) event-free survival.
Figure 2.
Kaplan-Meier overall survival curves for osteosarcoma (A) baseline stage, and (B) histopathologic necrosis after neoadjuvant chemotherapy.
Table 2.
Treatment outcomes of osteosarcoma.
| Overall survival % (95% Confidence Intervals) | |
| 3-year | 72 (67 – 78) |
| 5-year | 65 (59 – 71) |
| 10-year | 55 (44 – 69) |
| Event-free survival (%) | |
| 3-year | 43 (39 – 49) |
| 5-year | 40 (35 – 46) |
| 10-year | 25 (16 – 40) |
| Abandonment, n | |
| Abandoned prior to treatment | 34* |
| Abandoned active treatment | 42 |
| Deaths, n (%) | 100 (29.7%) |
| Causes of mortality: | |
| Disease progression | 75 |
| Infection-related | 18 |
| Cardiotoxicity | 7 |