BACKGROUNDSignificant efforts have been made to identify factors that differentiate patients treated with novel therapies, such as bortezomib in multiple myeloma (MM). The exact expression pattern and prognostic value of the cancer/testis antigen preferentially expressed antigen of melanoma (PRAME) in MM are unknown and were explored in this study.

METHODSThe transcript level of PRAME was detected in bone marrow specimens from 100 newly diagnosed MM patients using real-time quantitative polymerase chain reaction, and the prognostic value of PRAME was determined through retrospective survival analysis. PRAME expression higher than the upper limit of normal bone marrow was defined as PRAME overexpression or PRAME (+).

RESULTSSixty-two patients (62.0%) overexpressed PRAME. PRAME overexpression showed no prognostic significance to either overall survival (n = 100) or progression-free survival (PFS, n = 96, all P > 0.05) of patients. The patients were also categorized according to regimens with or without bortezomib. PRAME overexpression tended to be associated with a lower two-year PFS rate in patients treated with non-bortezomib-containing regimens (53.5% vs. 76.9%, P = 0.071). By contrast, it was not associated with the two-year PFS rate in patients with bortezomib-containing regimens (77.5% vs. 63.9%, P > 0.05). When the patients were categorized into PRAME (+) and PRAME (-) groups, treatment with bortezomibcontaining regimens predicted a higher two-year PFS rate in PRAME (+) patients (77.5% vs. 53.5%, P = 0.027) but showed no significant effect on two-year PFS rate in PRAME (-) patients (63.9% vs. 76.9%, P > 0.05).

CONCLUSIONPRAME overexpression might be an adverse prognostic factor of PFS in MM patients treated with non-bortezomib-containing regimens. Bortezomib improves PFS in patients overexpressing PRAME.