Newly diagnosed multiple myeloma patients with CD56 expression benefit more from autologous stem cell transplantation

Abstract: Background Several studies showed that lack of CD56 expression was a poor prognostic factor for patients with newly diagnosed multiple myeloma (NDMM). However, other studies were not able to confirm the prognostic value of CD56 in NDMM. This study aimed to evaluate the prognostic value of CD56 expression for patients with NDMM who received autologous stem cell transplantation (ASCT). Methods We retrospectively analyzed 394 patients with NDMM under 66 years old and the propensity score matching technique was used to reduce the bias between two groups. Results CD56 expression was observed in 265 (67.3%) patients, and 175 (44.4%) patients received ASCT. 44.9% (119/265) CD56 positive patients received ASCT; and 43.4% (56/129) CD56 negative patients received ASCT. Univariate and multivariate analyses showed that ASCT was correlated with longer OS (p < 0.001) and PFS (p < 0.001) for CD56 positive patients. ASCT may improve PFS of CD56 negative patients in univariate analysis, but it had no impact on PFS in multivariate analysis. Moreover, ASCT could not improve OS of CD56 negative patients in univariate and multivariate analysis (p > 0.05). In the propensity score matching analysis, 216 patients with CD56 expression were identified, 108 patients had received ASCT and 108 patients had no ASCT. Among 129 patients without CD56 expression, 80 patients, 40 in each group, were identified. Among 216 matched patients with CD56 expression, patients with ASCT had longer OS (87.6 vs.56.1 months, p < 0.001) and PFS (40.4 vs.27.6 months, p = 0.003). However, ASCT had no impact on OS and PFS for matched patients without CD56 expression (p > 0.05). Conclusions These results demonstrated that ASCT may improve OS and PFS of patients with CD56 expression and had little impact on survival of CD56 negative patients.