Prostate Stem Cell Antigen Single Nucleotide Polymorphisms Influence Risk of Estrogen Receptor Negative Breast Cancer in Korean Females

Introduction: Breast cancer is the second leading cancer in Korean women. To assess potential geneticassociations between the prostate stem cell antigen (PSCA) gene in the chromosome 8q24 locus and breastcancer risk in Korean women, 13 SNPs were selected and associations with breast cancer risk were analyzedwith reference to hormone receptor (HR) and menopausal status.
Methods:We analyzed DNA extractedfrom buffy coat from 456 patients and 461 control samples, using matrix-assisted laser desorption/ionizationtime-of-flight mass spectrometry (MALDI-TOF MS) based upon region-specific PCR followed by allelespecificsingle base primer extension reactions. Risks associated with PSCA genotypes and haplotypes wereestimated with chi-square test (χ2 -test), and polytomous logistic regression models using odds ratios (OR)and 95% confidence intervals (CIs), by HR and menopausal status.
Results: In case-control analysis, oddsratios (OR) of rs2294009, rs2294008, rs2978981, rs2920298, rs2976395, and rs2976396 were statisticallysignificant only among women with estrogen receptor (ER) negative cancers, and those of rs2294008,rs2978981, rs2294010, rs2920298, rs2976394, rs10216533, and rs2976396 were statistically significant onlyin pre-menopausal women, and not in postmenopausal women. Risk with the TTGGCAA haplotype wassignificantly elevated in ER (-) status (OR= 1.48, 95% CI= 1.03~2.12, p<0.05). Especially risk of allele T ofrs2294008 is significantly low in pre-menopausal breast cancer patients and AA genotype of rs2976395 inER (-) status represents the increase of OR value.
Conclusion: This report indicated for the first time thatassociations exist between PSCA SNPs and breast cancer susceptibility in Korean women, particularly thosewho are pre-menopausal with an estrogen receptor negative tumor status.