Genetic polymorphisms of platelet adhesive molecules:: association with breast cancer risk and clinical presentation

The main platelet adhesive receptors integrin alpha2beta1, integrin alphaIIbbeta3 and glycoprotein (GP) Ibalpha are also expressed in breast carcinoma cells. They play a key role in tumor cell-induced platelet aggregation and in adhesive interactions necessary for tumoral invasion and metastasis. Several polymorphisms affecting these molecules, two in integrin alpha2 (C807T and G1648A), one in integrin beta3 (T1565C) and one in GP Ibalpha (VNTR), influencing their levels, structure, and possibly their function, have been previously described and associated with cardiovascular diseases. In this study, we investigated the association of these polymorphisms with breast cancer risk or clinical presentation. We studied 101 patients with invasive breast cancer. The main prognostic variables were recorded, and genomic PCR analysis of these polymorphisms was performed. A group of 101 control subjects matched on age and sex was studied and compared with patients. No association was found between VNTR (GP Ibalpha) polymorphism and breast cancer risk or presentation. Genotype and allele frequencies of C807T and G1648A polymorphisms of integrin alpha2 were not statistically different in breast cancer patients and controls, although we found an association between the 1648G/G genotype and higher disease stages (III and IV) (p=0.02). Breast cancer risk was higher in carriers of beta3 integrin T/T genotype (OR=2.08, 95% CI=1.04-4.16, p=0.04). Furthermore, genotype 1565T/T was also associated with axillary nodal metastasis (p=0.017) and with tumoral diameter greater than 2 cm (p=0.02). Although confirmatory studies are needed, our results suggest that polymorphic genetic variation of integrins expressed in platelets and epithelial breast cells could modify the risk and the biological aggressiveness of breast carcinomas.