Incidence, epidemiology and treatment results of osteosarcoma in Finland – a nationwide population-based study

Figures & data

Table I. Histological review of the 144 osteosarcomas included in the analysis by five-year periods.

	1991–1995	1996–2000	2001–2005	Total
Conventional	34	43	28	107
Osteoblastic	31	35	20	86
Chondroblastic	2	6	7	15
Fibroblastic	1	2	1	4
Telangiectatic	0	3	0	3
Parosteal	2	6	0	8
Periosteal	5	4	0	9
Low-grade central	1	2	1	4
Small cell	1	0	1	2
Not otherwise specified	3	6	4	13
Total	46	64	34	144

Table II. Demographic data by five-year time periods.

	1991–1995	1996–2000	2001–2005	p^a
Sex (M/F)	1.875	1.286	0.619	0.054
Age, mean (percentage over 40 years)	24 (10.9)	24 (17.2)	31 (32.4)	0.204 (0.020)
Axial/peripheral	0.314	0.280	0.545	0.332
Percentage of metastatic disease at diagnosis	19.6	15.6	26.5	0.434
Percentage of low-grade tumors	15.2	14.1	8.8	0.750

^aBy χ² test.

Table III. Description of tumour, patient and treatment characteristics of the 116 patients with local disease, and the corresponding estimates of 10-year metastases-free and sarcoma-specific survival.

Characteristics	No of patients	10-Year SSS	p^f	95% CI	10-Year MFS	p^f	95% CI
Time of diagnosis
1991–1995	37	64%	0.230	0.439–1.219	59%	0.048	0.36–0.99
1995–2000	54	76%			75%
2001–2005	25	80%			83%
Axial vs. peripheral
Axial	29	65%	0.144	0.27–1.22	72%	0.932	0.45–2.39
Peripheral	87	75%			71%
Sex
Male	60	68%	0.302	0.33–1.41	64%	0.052	0.24–1.02
Female	56	78%			79%
Age at diagnosis
Mean 25.5 years			0.078^g	1.00–1.04		0.976^g	0.98–1.02
Range 7.8–77.1 years
Tumor grade
Low	18	94%	0.07	0.95–3.57
High	98	69%
Extent of surgery^a
Limb-sparing	68	77%	0.527	0.26–1.99	72%	0.512	0.29–1.84
Amputation	18	72%			72%
Margin status^b
Intralesional	2	50%	0.667	0.41–1.78	100%	0.895	0.55–1.99
Marginal	76	75%			71%
Wide	28	86%			82%
Radical	4	50%			50%
Major deviation from chemotherapy protocol^c
Present	16	43%	0.009	1.28–7.77	49%	0.067	0.92–5.54
Absent	41	75%			71%
Histologic response to chemotherapy^d
Good	24	92%	0.013	1.22–22.65	83%	0.124	0.79–5.77
Poor	48	62%			62%
Development of local recurrence
Yes	21	21%	<0.001	4.25–18.69
No	89	88%
Formal inclusion in trial^e
Yes	41	53%	0.011	1.20–5.31	53%	0.034	1.04–4.18
No	57	80%			76%

CI, Confidence interval; MFS, metastases-free survival; SSS, sarcoma-specific survival.

^aIn 86 extremity tumor patients having operation. ^bIn 110 patients having operation. ^cIn 57 patients with sufficient data. ^dAccording to protocol in question; recorded in 72 cases. ^eHigh-grade tumors. ^fLog-rank-test, except for ^gCox analysis.

Figure 1. Sarcoma-specific survival by five-year periods for the whole study population: 1991–1995 (blue), 1996–2000 (green), 2001–2005 (brown).

Figure 2. Event-free survival for the 116 patients with local disease at presentation.

Table IV. Multivariate analyses of prognostic factors for metastases-free survival and sarcoma-specific survival.

MFS		SSS
Factor	P-value (95% CI)	Factor	P-value (95% CI)
Time of diagnosis	0.101 (0.380–1.089)	Histologic response to chemotherapy^b	0.255 (0.532–10.798)
Formal inclusion in trial^a	0.101 (0.890–3.689)	Formal inclusion in trial^a	0.179 (0.612–13.87)
		Major deviation from chemotherapy protocol^c	0.002 (1.994–21.151)
		Development of local recurrence	<0.001 (5.700–66.596)

CI, Confidence Interval; MFS, metastases-free survival; SSS, sarcoma-spesific survival.

^aHigh-grade tumors. ^bAccording to protocol in question; recorded in 71 cases. ^cIn 61 patients with sufficient data.