Immunohistochemical expression of mTOR in germinal center and nongerminal center group of diffuse large B-cell lymphoma: a clinicopathological study

Abstract

Background: The mammalian target of rapamycin (mTOR) pathway regulates many major cellular processes and is implicated in an increasing number of neoplasms, including lymphoma.

Patients and methods: We correlated immunohistochemical expression of mTOR with germinal center and nongerminal center phenotype, B cell lymphoma-2 (bcl-2) and cellular homolog of the retroviral v-myconcogene (c-myc) expression, and International Prognostic Index (IPI) score in 31 patients with diffuse large B-cell lymphoma (DLBCL).

Results: Virtually all patients in our study with high mTOR scores had a germinal center phenotype. Furthermore within the germinal center subgroup, patients with high mTOR scores were associated with higher IPI scores (P < .001).

Conclusion: Based on our results we propose that within the category of germinal center phenotype of DLBCL, mTOR expression might help identify a subset of patients with potentially more aggressive tumors who might benefit from use of targeted therapy using mTOR inhibitors.

Keywords: Germinal center and nongerminal center phenotype; Immunohistochemistry; International prognostic index; Prognostic markers; Targeted therapy.