Journal of Experimental & Clinical Cancer Research 2009, 28:115 http://www.jeccr.com/content/28/1/115 TFhigeufrloew1diagram of included/excluded studies The flow diagram of included/excluded studies. were extracted respectively and further assessed by Rev- man 4.2 software. Consequently, the following results reported 18 studies. As shown in Table 3, for Arg/Arg vs Pro/Pro, the data avail- able for our meta-analysis were obtained from 18 case- control studies of 7377 cases and 6450 controls, of which 6288 cases and 5112 controls had the Arg/Arg genotype and 1089 cases and 1338 controls had the Pro/Pro geno- type of the TP53 codon 72. The overall OR was 1.20 (95% CI = 0.96–1.50) and the test for overall effect Z value was 1.58 (P > 0.05). For dominant model (Arg/Arg+Arg/Pro versus Pro/Pro), the data available for our meta-analysis were obtained from 18 case-control studies containing 12226 cases and 10782 controls, of which 11137 cases and 9444 controls had the combined genotypes of Arg/ Arg and Arg/Pro, while 1089 cases and 1338 controls had the homozygote Pro/Pro genotype. The overall OR was 1.12 (95% CI = 0.96–1.32) and the test for overall effect Z value was 1.47 (P > 0.05). Similarly, for recessive model (Arg/Arg versus Arg/Pro+Pro/Pro), the data were extracted from the 18 case-control studies concerning 12226 cases and 10782 controls, of which 6288 cases and 5112 con- trols had the wild-type homozygote Arg/Arg genotype while 5938 cases and 5670 controls had the combined variant genotypes (Arg/Pro and Pro/Pro) of the TP53 codon 72. The overall OR was 1.13 (95% CI = 0.98–1.31) and the test for overall effect Z value was 1.65 (P > 0.05). Considering the possible impact of ethnic variation on the results, we conducted subgroup analysis concerning Asians, Caucasians and Africans, respectively. Likewise, the subgroup analyses failed to suggest marked associa- tion between TP53 codon 72 polymorphisms and breast cancer risk in Asians, Caucasians and Africans. Sensitivity analysis In order to compare the difference and evaluate the sensi- tivity of the meta-analyses, we also presented the results of the fixed-effect models as listed in Table 3. In all, the results were not significantly different between the two models, suggesting the robustness of the meta-analyses. Moreover, we also conducted one-way sensitivity analy- sis[60] to evaluate the stability of the meta-analysis. The statistical significance of the results was not altered when any single study was omitted (data not shown), confirm- ing the stability of the results. Hence, results of the sensi- tivity analysis suggest that the data in this meta-analysis are relatively stable and credible. Bias diagnostics Funnel plots were created for assessment of possible pub- lication biases. Then, Egger's linear regression tests were used to assess the symmetric of the plots. As shown in Table 4, for the dominant model, the data suggest that the funnel plot is symmetrical. However, for the additive and recessive model, the results indicate possible asymmetric of the funnel plots. Therefore, we further calculated the Nfs0.05 for evaluation of the stability of the results. Conse- quently, the Nfs0.05 were 237, 143 and 271 for additive, dominant model and recessive model respectively, which were more than five times of the number of the included studies, suggesting that the results of these meta-analyses are relatively stable and the publication biases might not have an evident influence on the results of the meta-anal- yses. Discussion In the present study, the results of meta-analyses showed that individuals with TP53 codon 72 polymorphism might not have significant associations with increased or decreased susceptibility to breast carcinoma. A previous meta-analysis conducted by Koushik et al. [61] regarding cervical cancer suggests that homozygote Arg/ Arg genotype increases susceptibility to both squamous cell carcinoma and adenocarcinoma. While another meta- analysis [62] indicates that Arg/Arg genotype only associ- ates with increased risk of cervical adenocarcinoma but not squamous cell carcinoma. Then, Sousa et al. [63] failed to demonstrate Arg/Arg genotype as a risk marker for the development of cervical lesions in most of Euro- pean countries. Conversely, nonassociations of TP53 codon 72 polymorphism with lung carcinoma [64] and gastric cancer [65] risk were found by meta-analysis. Nev- ertheless, An updated meta-analysis concerning lung can- cer implied that Pro allele is a low-penetrant risk factor for Page 4 of 9 (page number not for citation purposes)