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

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 370 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 250 (67.6%) patients, and only half of transplant-eligible patients received ASCT for financial and adverse effects concerns after induction therapy. 54.8% (137/250) CD56 positive patients received ASCT; and 47.5% (57/120) CD56 negative patients received ASCT. Univariate and multivariate analyses showed that ASCT was correlated with longer overall survival (OS) (p < 0.001) and progression-free survival (PFS) (p < 0.001) for CD56 positive patients. However, ASCT had no impact on OS and PFS in univariate and multivariate analysis (p > 0.05). In the propensity score matching analysis, 186 CD56 positive patients were identified, 93 patients had received ASCT and 93 patients had no ASCT. Among 120 CD56 negative patients, 80 patients, 40 in each group, were identified. Among 186 matched CD56 positive patients, patients with ASCT had longer OS (87.6 vs.56.1 months, p = 0.049) and PFS (36.7 vs.30.9 months, p = 0.040). However, ASCT had no impact on OS and PFS for matched CD56 negative patients (p > 0.05). CONCLUSIONS: These results demonstrated that ASCT may improve OS and PFS of CD56 positive patients and had no impact on survival of CD56 negative patients.