299 - Association of alpha2a and beta2 adrenoceptors expression with clinical outcome in breast cancer
|Date||28 September 2012|
|Event||ESMO Congress 2012|
|Topics|| Breast Cancer
Y. Du, J. Lu
Previous studies have shown that alpha2-adrenoceptor antagonists can inhibit the growth of breast cancer cells. The action of beta2 adrenoceptors on cell proliferation is still controversial. In this study, we investigated the association of alpha2a and beta2 adrenoceptors expression with tumor-relevant biological markers and clinical outcome. Immunohistochemistry assay was performed on paraffin-embedded tumors to detect alpha2a and beta2 adrenoceptor expression in 220 operable breast tumors. We initially demonstrated that alpha2a expression was associated with Her-2 status (P = 0.048) and a marginal significance was observed between alpha2a expression and ER (P = 0.061). We also find that beta2 expression was not associated with any tumor-relevant biological markers. Kaplan-Meier models trended to show associations between different beta2 expression and DFS (P = 0.092). Further analysis was made and we found in hormone receptor positive breast cancer patients, strong beta2 expression correlated with better DFS than weak beta2 expression (P = 0.031). Multivariate analysis demonstrated that beta2 adrenoceptor (HR = 0.31, P = 0.039) and lymph node (HR = 2.85, P = 0.031) were independent predictors of DFS in hormone receptor positive breast cancer patients. In conclusion, this study showed that strong alpha2a expression occurred in ER positive and Her-2 negative breast cancers. In hormone receptor positive breast cancer patients, strong beta2 expression correlates with better DFS than weak beta2 expression. In hormone receptor positive breast cancer patients, beta2 ADR could be an independent predictors of DFS. Our results also suggest that the expression of beta2 adrenoceptor may be regulated by estrogen and progesterone or intercross may exist between the two pathways of beta2 adrenoceptor and hormone receptor.Disclosure
All authors have declared no conflicts of interest.