RAD 51 Gene 135G/C polymorphism and the risk of four types of common cancers: a meta-analysis

Table 1 Characteristics of 22 published studies included in this meta-analysis

First author	Year	Study location	Cancer type	Sample size	Source of controls	Genotyping methods
1. Lu JC	2006	USA	SCCHN	716/719	HCC	PCR-RFLP
2. Gil J	2011	Poland	CC	133/100	HCC	PCR-RFLP
3. Webb PM	2005	Australia	OC	548/335	PCC	PCR
4. Gresner P	2012	Poland	SCCHN	81/111	PCC	PCR
5. Seedhouse C	2004	UK	AL	267/186	PCC	PCR
6. Jawad M	2006	UK	AL	267/186	PCC	PCR
7. Krupa R	2011	Poland	CC	100/100	HCC	PCR
8. Sliwinski T	2010	Poland	SCCHN	288/353	HCC	PCR-RFLP
9. Hamdy MS	2011	Egypt	AL	50/30	HCC	PCR-RFLP
10. Liu L	2011	China	AL	625/704	HCC	PCR
11. Romanowicz-MakowskaH	2012	Poland	CC	320/320	HCC	PCR
12. WerbouckJ	2008	Belgium	SCCHN	152/157	HCC	PCR
13. Romanowicz-MakowskaH	2011	Poland	OC	120/120	HCC	PCR
14. Bhatla D	2008	USA	AL	452/646	PCC	PCR
15. Voso MT	2007	Italy	AL	160/161	HCC	PCR-RFLP
16. Mucha B	2012	Poland	CC	200/200	HCC	PCR-RFLP
17. Zhang ZQ	2009	China	AL	166/458	HCC	PCR-RFLP
18. Auranen A (UK)	2005	UK	OC	729/847	PCC	PCR
18. Auranen A (USA)	2005	USA	OC	326/419	PCC	PCR
18. Auranen A (Danish)	2005	Denmark	OC	278/699	PCC	PCR
21. Yang L	2011	China	AL	379/704	HCC	PCR
22. Rollinson S	2006	UK	AL	479/952	PCC	PCR

SCCHN: squamous cell carcinoma of the head and neck; CC: colorectal cancer; OC: ovarian cancer; AL: acute leukaemia; HCC: hospital-based case-control; PCC: population-based case-control; PCR: polymerase chain reaction; RFLP: restriction fragment length polymorphism.