XRCC3 Thr241Met polymorphism and breast cancer risk: a meta-analysis

Abstract

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. Abstract XRCC3 (X-ray repair complementing defective repair in Chinese hamster cells 3) is a member of the RecA/ Rad51-related protein family that participates in homologous recombination, maintaining chromosome stability and participating in DNA repair. Attention has been drawn upon the association of XRCC3 Thr241Met polymorphism with breast cancer risk. The present meta-analysis aims to examine whether XRCC3 Thr241Met polymorphism status is associated with breast cancer risk. Apart from the overall meta-analysis, separate analyses were performed on Chinese and non-Chinese populations, in order to investigate race-specific effects. Eligible articles were identified by a search of MEDLINE bibliographical database for the period up to August 2009. Twenty case-control studies on nonChinese subjects (19,575 cases and 21,125 controls) and three case-control studies on Chinese subjects (1,216 cases and 1,112 controls) were eligible. Pooled odds ratios (OR) were appropriately derived from fixed-effects or randomeffects models. At the overall analysis, the T allele was associated with elevated breast cancer risk mainly following a recessive model (pooled OR = 1.064, 95% CI: 1.007-1.124, fixed effects), given that the effect was more pronounced in homozygous carriers (pooled OR = 1.073, 95% CI: 1.010-1.140, fixed effects). The association seemed confined in non-Chinese populations, once again following a recessive model (pooled OR = 1.072, 95% CI: 1.014-1.133, fixed effects). Concerning Chinese populations, no consistent results were demonstrated. In conclusion, the XRCC3 Thr241Met T allele seems associated with elevated breast cancer risk in non-Chinese subjects. The need for additional studies on Chinese populations seems warranted.

Four polymorphisms in cytochrome P450 1A1 (CYP1A1) gene and breast cancer risk: a meta-analysis

“…Contrary to our meta-analysis, Chen et al demonstrated that the association implicating the A2455G G allele pertained to East Asian populations and premenopausal women. Regarding the issue of race, close inspection of data revealed that during the examination of ''East Asian'' populations, Chen et al had merged a study on Indian populations [56] with other studies on Chinese and Japanese subjects; in our algorithm [12][13][14][15], Indian studies have been included in the greater subset of Caucasian (Indo-european) race, a fact which seems closer to the existing data in the field of physical anthropology [70]. Importantly, it should be declared that merging of Chinese/ Japanese and Indian studies given the larger sample of studies in the present meta-analysis still did not lead to significant results (data not shown).…”

“…For each polymorphism, four different ORs were calculated: (i) heterozygous carriers versus ''wild type'', (ii) homozygous carriers versus ''wild type'', (iii) dominant model, i.e., heterozygous and homozygous carriers grouped together versus wild type, and (iv) recessive model, i.e., homozygous carriers versus ''wild type'' and heterozygous carriers grouped together. Separate analyses were performed in Caucasian (IndoEuropean), Chinese, and African populations, according to the algorithm adopted in our previous meta-analyses [12][13][14][15]. Separate analyses were performed on premenopausal and postmenopausal women.…”

“…Separate analyses were performed on premenopausal and postmenopausal women. In case of zero cells, an appropriate continuity correction (addition of 0.5) was implemented [12].…”

Three polymorphisms in cytochrome P450 1B1 (CYP1B1) gene and breast cancer risk: a meta-analysis

“…homozygous carriers versus 'wild type' and heterozygous carriers grouped together. Separate racespecific analyses were considered in case relevant data existed, according to the algorithm adopted in our previous meta-analyses [10][11][12][13][14]. In case of zero cells, an appropriate continuity correction (addition of 0.5) was implemented [10].…”

Validating the meta-analytical results on MDM2, CASP8, XRCC3 polymorphisms and breast cancer risk: examination of Hardy–Weinberg Equilibrium

“…Following the valuable methodological remarks by Mao et al [1] regarding our metaanalysis on glutathione-S-transferase polymorphisms and breast cancer risk [2], we decided to present elaborate sensitivity analyses on Hardy-Weinberg Equilibrium (HWE) in our three previous meta-analyses examining MDM2 SNP309 [3], CASP8 [4] and XRCC3 Thr241Met [5] polymorphisms and breast cancer risk.…”