Activation of mammalian target of rapamycin in diffuse large B-cell lymphoma: A clinicopathological study

Cell signaling by a highly conserved serine/threonine kinase mammalian target of rapamycin (mTOR) has been shown to play a critical role in cell proliferation. We analyzed the immunohistochemical expression of mTOR, pmTOR and bcl-2 in 55 patients with diffuse large B-cell lymphoma and correlated it with clinical parameters and clinical outcomes. On univariate analysis, higher expression of mTOR was associated with male gender, older age, and higher IPI score. Patients with a high total mTOR score showed a trend toward shorter survival. Based on our results we propose that use of targeted therapy with mTOR inhibitors, in a subset of diffuse large B-cell lymphoma patients may help improve patient survival.