Table 4. Excess of relative risk per cumulative activity of ¹³¹I in GBq (ERR) according to external radiotherapy for major types of SPMs.

	No external radiotherapy		External radiotherapy		All the patients
Type of SPM	ERR per GBq of 131Ia (95% CI)	Test of trendb	ERR per GBq of 131Ia (95% CI)	Test of trendb	ERR per GBq of 131Ic (95% CI)	Test of trendb	Test of heterogeneityd
Solid cancerse	0.03 (0.002–0.08)	0.03	0.04 (0.00006–0.09)	0.05	0.04 (0.009–0.07)	<0.01	0.6
Soft-tissue and bone cancer	0.29 (?–1.74)f	0.2	1.04 (?–3.93)f	<0.001	0.61 (?–2.41)f	<0.001	0.9
Colorectal cancer	0.15 (0.02–0.38)	0.01	0.02 (?–0.20)f	0.7	0.10 (0.08–0.27)	0.03	0.4
Breast cancer	0.002 (?–0.07)f	1.0	−0.02 (?–0.04)f	0.3	−0.01 (?–0.04)f	0.6	0.3
Leukaemias	0.22 (?–1.30)f	0.2	0.59 (?–2.34)f	<0.01	0.39 (?–1.54)f	0.01	0.4

^aStratified on study group.

^bTest of trend for a linear dose–effect relationship: P-value.

^cAdjusted on external radiotherapy and stratified on study group.

^dTest of heterogeneity of the ERR between patients exposed and nonexposed to external radiotherapy.

^eAll cancers except leukaemias, thyroid cancers, and nonmelanoma skin cancers.

^fLower bound not calculable.