Expression of BAG-1 in Invasive Breast Carcinomas

Abstract

BAG-1 is overexpressed in the majority of invasive breast carcinomas. Although BAG-1 did not correlate with conventional prognostic factors, its overexpression, especially the nuclear expression, may be associated with a shorter disease-free and overall survival. Our preliminary data strongly indicate that further investigation is warranted to define the role of BAG-1 as an independent prognostic factor in patients with newly diagnosed breast cancer.

BAG‐1, An Anti‐Apoptotic Tumour Marker

“…We recently conducted a retrospective pilot study of BAG-1 expression in 140 patients with invasive breast cancer (53). BAG-1 expression was detected by a commercially available polyclonal antibody that did not cross-react with background proteins or other BAG-1-like proteins, such as BAG-1, BAG-3, and BAG-4.…”

BAG-1 expression and function in human cancer

“…A strong relationship between nuclear BAG-1 expression and tumour grade/differentiation has been identified in two studies, with relatively high levels of nuclear BAG-1 expression in low grade tumours (Tang et al, 1999;Townsend et al, 2002). By contrast, Turner et al (2001) reported no correlation between tumour grade and BAG-1 expression.…”

“…This is particularly interesting since it was suggested that this might provide a means by which node negative patients with a relatively poorer prognosis could be selected for further adjuvant therapies, and conversely enable better prognosis node negative patients to avoid such therapies with their concomitant side effects. This exciting finding awaits confirmation (Tang et al, 1999;Townsend et al, 2002). Tang et al (1999) found no correlations between BAG-1 expression and outcome in univariate analysis and conversely reported that increased BAG-1 expression correlated with decreased disease free and overall survival in a multivariate analysis controlled for tumour differentiation.…”

“…This exciting finding awaits confirmation (Tang et al, 1999;Townsend et al, 2002). Tang et al (1999) found no correlations between BAG-1 expression and outcome in univariate analysis and conversely reported that increased BAG-1 expression correlated with decreased disease free and overall survival in a multivariate analysis controlled for tumour differentiation. In our own study no correlations were found between cytoplasmic BAG-1 and outcome (Townsend et al, 2002).…”

“…Four large immunohistochemical studies of the expression and clinical significance of BAG-1 in breast cancer have been reported and these are summarised in Table 1 (Tang et al, 1999;Turner et al, 2001;Sjostrom et al, 2002;Townsend et al, 2002). Some of the results from these studies are inconsistent and further studies are required to fully understand the role of BAG-1 expression in breast cancer (Cutress et al, 2001).…”