We investigated cytosolic PARP-1 activity, 53BP1 protein levels and BRCA1 promoter methylation in 155 surgical breast tumour samples from patients without familial breast cancer history or known BRCA1 mutations who were treated between January 2006 and November 2009 and evaluated their statistical association with classical predictive and prognostic factors. Here, PARP1 is linked to breast carcinoma.