Table 1. Studies examining SBC risk in PCa patients receiving EBRT.

Study	Type of data	Comparison group	No. of patients receiving EBRT	Median follow-up, years	Risk of SBC	Magnitude of SBC risk
Wu, 2022 (20)	SEER registry	Non-irradiated patients	97,799	10.5	Increased	HR: 1.60 (95% CI: 1.50–1.70), P<0.01
Davis, 2014 (21)	SEER registry	General population	25,569	Not specified	Increased	SIR: 1.42 (95% CI: 1.28–1.58)
Guo, 2019 (22)	SEER registry	Non-irradiated patients	143,679	6.1	Increased	HR: 1.41 (95% CI: 1.33–1.51), P<0.01
Abern, 2013 (23)	SEER registry	General population	83,110	5.4	Increased	SIR: 1.14 (95% CI: 1.08–1.20)
Aksnessæther, 2020 (26)	Randomized controlled trial	PCa patients receiving androgen deprivation therapy	429	12.2	Increased	HR: 2.54 (95% CI: 1.14–5.60), P=0.023
Jahreiß, 2021 (25)	Netherlands cancer registry	Radical prostatectomy	42,069	5.2	Increased	sHR: 1.83 (95% CI: 1.63–2.05), P<0.01
Jahreiß, 2021 (25)	Netherlands cancer registry	General population	42,069	5.2	Increased	SIR: 1.33 (95% CI: 1.26–1.44)

SBC, secondary bladder cancer; PCa, prostate cancer; EBRT, external beam radiotherapy; CI, confidence interval; SEER, the surveillance, epidemiology, and end results; HR, hazard ratio; SIR, standardized incidence ratio; sHR, subhazard ratio.