Estrogen receptor β1 in diffuse large B-cell lymphoma growth and as a prognostic biomarker

Diffuse large B-cell lymphoma (DLBCL) shows a higher incidence in males versus females. Epidemiological studies have shown that female gender is a favorable prognostic factor, which may be explained by estrogens. Here we show that when grafting human DLBCL cells to immunocompromised mice, tumor growth in males is faster. When treating mice grafted with either germinal center or activated B-cell like DLBCL cells with the selective estrogen receptor beta (ER beta) agonist diarylpropionitrile, tumor growth was significantly inhibited. Furthermore, nuclear ER beta 1 expression analysis in primary DLBCL's by immunohistochemistry revealed expression in 89% of the cases. Nuclear ERb1 expression was in a univariate and multivariate analysis, an independent prognostic factor for adverse progression-free survival in Rituximab-chemotherapy treated DLBCL (p = 0.02 and p = 0.04, respectively). These results suggest that estrogen signaling through ERb1 is an interesting future therapeutic target for treatment of DLBCL, and that ERb1 expression can be used as a prognostic marker.