Table 3. Cox regression analysis of sarcoma-related survival in patients with radiation-induced sarcoma (cases) and sporadic sarcomas (controls).

(A) Patients with soft tissue sarcomaa
	All, n=204b			Without metastasis at diagnosis, n=178b
Prognostic factor	P-value	HR	95% CI for HR	P-value	HR	95% CI for HR
Radiation-induced sarcoma	0.543	0.87	0.56–1.35	0.212	0.72	0.44–1.20
Yes (ref)
No
Metastases at diagnosis	<0.001	0.34	0.19–0.61	Not relevant
Yes (ref)
No
Complete surgical remission	<0.001	4.96	3.14–7.84	<0.001	5.38	3.35–8.65
Yes (ref)
No
Microscopic tumour necrosis	<0.001	0.39	0.23–0.66	<0.001	0.35	0.21–0.60
Yes (ref)
No

(B) Patients with osteosarcoma in bone
	All, n=81c			Without metastasis at diagnosis, n=63c
Prognostic factor	P-value	HR	95% CI for HR	P-value	HR	95% CI for HR
Radiation-induced sarcoma	0.902	0.95	0.38–2.34	0.758	0.86	0.33–2.22
Yes
No (ref)
Metastases at diagnosis	0.008	0.36	0.17–0.76	Not relevant
Yes (ref)
No
Complete surgical remission	<0.001	5.11	2.38–11.00	0.04	4.74	1.67–13.46
Yes (ref)
No
Site	0.026	2.80	1.13–6.96	0.038	3.31	1.07–10.24
Extremity/trunk wall (ref)
Head/abdomen/axial/thoracic

Abbreviations: CI=confidence interval; HR=hazard ratio; ref=reference.

^aIncluding MFH, angiosarcoma, malignant peripheral nerve sheath tumour and leiomyosarcoma, but not osteosarcoma in soft tissue.

^bGender, age at diagnosis, histology, time period at diagnosis, tumour size and site were not significant prognostic factors.

^cGender, age at diagnosis, time period at diagnosis, tumour size and microscopic tumour necrosis were not significant prognostic factors.