First author Själander Weston (Caucasian) Weston (African) Li Wang-Gohrke Buyru Huang Katiyar Mabrouk Kalemi Tommiska Baynes Gochhait Khadang Schmidt Sprague Zhang Akkiprik 24 6 6 11 282 64 64 20 18 26 825 1107 86 83 2797 823 21 25 Cases Arg/Pro 93 27 9 11 221 39 100 51 9 13 617 768 109 109 2008 570 45 50 95 32 1 6 49 12 36 6 3 3 109 148 48 29 386 89 17 20 61 3 12 10 300 21 114 9 19 10 403 1177 76 75 2024 705 47 46 Controls Arg/Pro 253 42 14 26 203 43 138 24 26 32 278 854 160 90 1523 490 87 49 375 72 4 14 40 12 30 8 4 9 52 166 97 40 287 83 33 12 Journal of Experimental & Clinical Cancer Research 2009, 28:115 http://www.jeccr.com/content/28/1/115 Table 2: Distribution of TP53 codon 72 genotype among breast cancer cases and controls included in the meta-analysis Arg/Arg Pro/Pro Arg/Arg Pro/Pro Chi-square cans, respectively. Ultimately, statistically similar results were obtained, confirming nonassociation of TP53 codon 72 polymorphism with breast cancer risk. A well-known risk factor, HPV infection, is thought to have an association with increased susceptibility to some cancers such as cervical [70] and oral cancer [71]. Evi- dence suggests that P53Arg72 protein may be more sus- ceptible than P53Pro72 protein to HPV mediated degradation, thus increasing risk of HPV associated can- cers [17]. Growing body of literature indicates HPV infec- tion as a possible risk factor for breast cancer [72]. However, we did not further investigate the possible asso- ciation of HPV infection with TP53 codon 72 polymor- phism due to the insufficient data in the primary included studies. Table 3: Main results of the pooled data in the meta-analysis Heterogeneity is a potential problem when interpreting the results of meta-analysis [73]. In the present study, sig- nificant between-study heterogeneity existed in overall comparisons. Nevertheless, when the data were stratified by race, the heterogeneity was decreased or removed, sug- gesting that differences of genetic backgrounds and the environment existed among different ethnicities. In the present meta-analysis, we excluded the studies in which the control groups were deviate from HWE. Thus, the between-study heterogeneity might be reduced. Moreo- ver, random-effect models were used for combination of the data. Accordingly, the results may be credible and sta- ble although the heterogeneity seemed evident. Some limitations might be included in this study. First, in this meta-analysis, most published studies and papers Total Caucasian Asian African Total Caucasian Asian African No. of cases/ controls 12226/10782 11549/9830 631/873 46/79 12226/10782 11549/9830 631/873 46/79 Arg/Arg vs Pro/Pro (Arg/Arg+Arg/Pro) vs Pro/Pro Arg/Arg vs (Arg/Pro+Pro/Pro) OR (95%CI) P P (Q-test) OR (95%CI) P P (Q-test) OR (95%CI) P P (Q-test) 1.20 (0.96–1.50) 0.11 1.15 (0.91–1.44) 0.24 1.36 (0.61–3.03) 0.45 1.46 (0.38–5.62) 0.58 1.09 (0.99–1.20) 0.10 1.07 (0.96–1.18) 0.24 1.27 (0.94–1.71) 0.12 1.47 (0.39–5.62) 0.57 Random-effect model 0.000 1.12 (0.96–1.32) 0.14 0.001 1.11 (0.95–1.30) 0.17 0.000 1.19 (0.67–2.10) 0.55 0.76 1.12 (0.31–4.10) 0.86 Fixed-effect model 0.000 1.09 (0.99–1.19) 0.06 0.001 1.08 (0.98–1.19) 0.12 0.000 1.16 (0.89–1.51) 0.26 0.76 1.17 (0.33–4.14) 0.80 0.01 0.06 0.006 0.45 0.01 0.06 0.006 0.45 1.13 (0.98–1.31) 0.10 1.09 (0.93–1.27) 0.28 1.22 (0.72–2.05) 0.46 1.60 (0.63–4.06) 0.32 1.04 (0.99–1.10) 0.13 1.03 (0.98–1.09) 0.25 1.15 (0.92–1.44) 0.22 1.67 (0.80–3.48) 0.17 0.000 0.000 0.002 0.22 0.000 0.000 0.002 0.22 Page 6 of 9 (page number not for citation purposes) HWE (control) 3.681 1.189 0.001 0.109 0.485 1.657 1.545 1.205 1.432 3.326 0.183 0.414 0.413 1.873 0.001 0.03 0.406 0.038 P 0.055 0.276 0.979 0.741 0.486 0.198 0.214 0.272 0.231 0.068 0.669 0.520 0.521 0.171 0.983 0.862 0.524 0.846