The progesterone receptor exon 4 Val660Leu G/T polymorphism and risk of breast cancer in Australian women

Spurdle AB, Hopper JL, Chen X, McCredie MR, Giles GG, Venter DJ, Southey MC, Chenevix-Trench G (2002) The progesterone receptor exon 4 Val660Leu G/T polymorphism and risk of breast cancer in Australian women. Cancer Epidemiol Biomarkers Prev 11:439-443

An Alu insertion polymorphism of the progesterone receptor (PR) wasreported recently to be associated with a reduced risk of breast cancer, with risks of 0.8- and 0.3-fold associated with the heterozygote and homozygote genotypes, respectively. This intronic variant is considered to be in linkage disequilibrium with an exon 4 hinge region G to T Val660Leu polymorphism. We investigated whether the exon 4 PR polymorphism was associated with breast cancer in Australian women, using a population-based study of 1452 cases and 793 controls, half of whom were <40 years="" of="" age,="" and="" the="" other="" half="" were="" 40-59="" years="" of="" age.="" there="" was="" no="" difference="" in="" genotype="" distribution="" between="" cases="" and="" controls="" (p="0.5)" and="" no="" evidence="" of="" risk="" associated="" with="" either="" the="" gt="" or="" tt="" genotypes="" compared="" with="" the="" common="" gg="" genotype.="" the="" adjusted="" odds="" ratios="" (ors)="" were="" 0.97="" (95%="" confidence="" interval,="" 0.79-1.19)="" and="" 1.52="" (95%="" confidence="" interval,="" 0.87-2.66),="" respectively="" (p="0.8" and="" 0.1),="" and="" the="" results="" were="" independent="" of="" age="" and="" family="" history="" of="" breast="" cancer.="" our="" data="" provided="" no="" support="" for="" the="" previously="" reported="" decreased="" risk="" of="" breast="" cancer="" associated="" with="" the="" t="" allele,="" with="" 80%="" power="" to="" detect="" an="" or="" of="" 0.8="" or="" less="" for="" the="" heterozygote="" genotype="" and="" 90%="" power="" to="" detect="" an="" or="" of="" 0.3="" or="" less="" for="" the="" rare="" homozygous="" tt="" genotype.="" there="" was="" also="" no="" support="" for="" a="" greatly="" increased="" risk="" of="" breast="" cancer="" associated="" with="" the="" t="" allele,="" given="" that="" we="" had="" 80%="" power="" to="" detect="" risks="" of="" 1.3="" and="" 2.0="" associated="" with="" the="" gt="" and="" tt="" genotypes,="" respectively.="" we="" therefore="" conclude="" that="" this="" polymorphism="" is="" not="" associated="" with="" a="" markedly="" reduced="" or="" increased="" risk="" of="" breast="" cancer="" in="" australian="" women=""><60 years="" of="" age.="" however,="" despite="" its="" considerable="" size,="" our="" study="" cannot="" exclude="" a="" small="" reduced="" or="" increased="" risk="" associated="" with="" the="" t="" allele,="" especially="" the="" rare="" tt="">