MicroRNA signature is indicative of long term prognosis in diffuse large B-cell lymphoma

Purpose To compare microRNA (miR) expression between patients with diffuse large B-cell lymphoma (DLBCL) who had a poor prognosis to those who had a favorable prognosis. Methods The study group included 83 patients with diffuse large B-cell lymphoma (DLBCL) treated between the years 1995 and 2003 without rituximab in a single tertiary center for whom adequate tumor content was available. miR signature from tissue biopsies was compared between patients who relapsed within nine months from commencement of treatment (defined as poor prognosis, n=43) and those with disease-free survival of at least five years (defined as good prognosis, n=40). RNA was analyzed using custom microarrays. Quantitative real-time polymerase chain reaction (qRT-PCR) was used for technical validation of microarray results. An independent set of 13 samples was used for further validation. Results Eight miRs were found to be differently expressed between the two prognostic groups. The expression of the different miRs was verified by qRT-PCR, showing high correlation with the microarray data in both verification and independent set groups. No added value to the clinically based International Prognostic Index was found. Conclusion miR signature from DLBCL biopsies can discriminate between patients with favorable and poor prognoses.