Table 2. Summary of meta-analysis results for associations between telomere length and cancer risk.

Groups	Numbers		Heterogeneity		Associations (short vs. long)
	Study	Case/Control	P	I2	OR(95% CI)	P
Overall	62	23379/68792	<0.001	0.90	1.10(0.98–1.23)	0.09
Populations
Caucasian	51	18727/63183	<0.001	0.86	1.08(0.97–1.21)	0.18
Asian	10	4419/5265	<0.001	0.95	1.15(0.78–1.68)	0.49
African American	1	233/344	–	–	1.22(0.88–1.71)	0.23
Study design
Prospective	16	7925/48662	<0.001	0.82	1.02(0.87–1.19)	0.80
Retrospective	46	15454/20130	<0.001	0.91	1.14(0.98–1.33)	0.10
Skin cancer
Prospective	3	740/801	0.284	0.21	0.92(0.76–1.13)	0.44
Retrospective	7	2059/4087	<0.001	0.94	1.36(0.82–2.24)	0.23
Total	10	2799/4888	<0.001	0.91	1.17(0.83–1.66)	0.37
Tumors of urogenital system
Prospective	1	209/410	–	–	0.92(0.66–1.28)	0.61
Retrospective	9	2951/3393	<0.001	0.70	1.01(0.81–1.25)	0.95
Total	10	3160/3803	0.002	0.66	0.99(0.82–1.20)	0.95
Gastrointestinal tumor
Prospective	1	38/300	–	–	1.92(0.95–3.90)	0.07
Retrospective	8	3899/4846	<0.001	0.80	1.60(1.30–1.97)	8.20E-06
Total	9	3937/5146	<0.001	0.78	1.62(1.33–1.97)	2.03E-06
Breast cancer
Prospective	3	1839/2347	0.370	0	1.13(0.99–1.28)	0.06
Retrospective	5	2431/2522	<0.001	0.87	0.82(0.58–1.17)	0.28
Total	8	4270/4869	<0.001	0.82	0.96(0.78– 1.19)	0.70
Lung cancer
Prospective	3	1292/1291	0.330	0.10	0.78(0.67–0.91)	1.69E-03
Retrospective	5	1514/1530	<0.001	0.94	1.01(0.53–1.93)	0.97
Total	8	2806/2821	<0.001	0.90	0.91(0.63–1.31)	0.60
Head and neck cancer
Prospective	–
Retrospective	4	509/1156	0.019	0.70	1.86(1.23–2.82)	3.50E-03
Total	4	509/1156	0.019	0.70	1.86(1.23–2.82)	3.50E-03
Lymphoma
Prospective	–
Retrospective	3	561/561	<0.001	0.90	1.31(0.44–3.84)	0.63
Total	3	561/561	<0.001	0.90	1.31(0.44–3.84)	0.63
Other types of cancer
Prospective	5	3807/43513	<0.001	0.87	1.22(0.85–1.75)	0.29
Retrospective	5	1530/2035	<0.001	0.95	0.69(0.33–1.45)	0.32
Total	10	5337/45548	<0.001	0.94	0.92(0.64–1.32)	0.65