First Author Själander Weston Li Wang- Gohrke Buyru Huang Katiyar Mabrouk Kalemi Tommiska Baynes Gochhait Khadang Schmidt Sprague Zhang Akkiprik Journal of Experimental & Clinical Cancer Research 2009, 28:115 http://www.jeccr.com/content/28/1/115 Table 1: Characteristics of studies included in the meta-analysis Publication Year Number of Cases Number of Controls Types of Cases Type of controls Method Country Ref. No. 1996 1997 2002 2002 2003 2003 2003 2003 2005 2005 2007 2007 2007 2007 2007 2007 2008 212 81 28 577 115 200 77 30 42 1827 2023 576 221 5191 1912 84 95 689 147 50 579 76 282 41 49 51 736 2197 243 205 3834 1527 168 107 Ductal carcinoma (>80% of the total cases) NS NS NS NS NS 77 Sporadic breast cancer NS NS 888 unselected breast cancer; 939 familial breast cancer NS 243 sporadic breast cancer; 333 unrelated breast cancer 221 sporadic breast cancer NS 1708 invasive breast cancer; 204 in situ breast cancer NS NS Pooled individuals from several controls NS 50 healthy people (age-matched) NS 76 healthy people 282 healthy people 41 Normal healthy women (age- matched) NS 51 healthy women 736 healthy population NS 243 healthy females (ethnically and geographically matched) 205 healthy blood donors NS 1527 drivers (< 65 year) and roster of Medicare beneficiaries (65–74 year) 168 healthy controls (geographic- and age- matched) 107 age-matched healthy controls PCR-RFLP Sweden PCR-RFLP Germany AS-PCR AS-PCR PCR-RFLP PCR-CTPP PCR-RFLP PCR-RFLP PCR-RFLP TaqMan TaqMan PCR-RFLP AS-PCR TaqMan+ PCR- RFLP TaqMan USA China Turkey China India Tunisia UK Sweden UK India Iran UK USA PCR-RFLP China PCR-RFLP Turkey 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 59 58 AS-PCR: Allele Specific PCR; RFLP: restriction fragment length polymorphism; CTPP: confronting two-pair primers; NS: not specified developing lung cancer [66]. Thus, whether TP53 codon 72 polymorphism contributes to susceptibility to cancers varies in different types of cancer. In the present study, no evidence showed TP53 codon 72 polymorphism as a risk factor for breast cancer. The underlying mechanisms by which TP53 polymor- phism influences cancer risk are not fully understood. TP53 is the most frequently investigated gene that is often mutated in a variety of cancers. Nevertheless, several sin- gle-nucleotide polymorphisms have been studied and reported in TP53 gene [67]. The polymorphism of TP53 codon 72 occurs in a proline-rich region that is thought to play a critical role in the growth suppression and apop- totic functions of TP53 protein [68]. The two polymor- phic variants differ in their capability of binding the transcriptional protein, activating transcription and sup- pressing the transformation of some primary cells [69]. For example, Arg variant might induce cell apoptosis and suppress transformation more efficiently than Pro variant do, which may be due to the ability of the Arg variant to localize in mitochondria that regulates the release of cyto- chrome c into cytosol. However, the present meta-analysis indicates that neither Arg nor Pro carriers may have a sig- nificant association with breast cancer risk. It is likely that TP53 codon 72 polymorphisms rarely affect the tumori- genesis and progression of breast carcinoma. Considering that the same polymorphism may play different roles in cancer susceptibility among different ethnic populations and the frequencies of single nucleotide polymorphisms may be different ethnicity, we stratified the data by race into three groups concerning Asians, Caucasians or Afri- Page 5 of 9 (page number not for citation purposes)