Correlation between circulating myeloma cells and marrow myeloma cells in patients with multiple myeloma and its clinical significance

Abstract

Objective To investigate the correlation between circulating myeloma cells (CMCs) and marrow myeloma cells (MMCs) in patients with multiple myeloma (MM) and assess the feasibility of CMCs reflecting the tumor load and MM progression. Methods It is a non-intervention clinical study. Between July 2015 and October 2016, 82 patients with MM from First Affiliated Hospital of Zhengzhou University were enrolled.They were divided into three groups according to the diagnosis and response criteria: newly diagnosed and relapsed group (35 cases), partial remission (PR) group (31 cases) and complete remission (CR) group (16 cases), and divided into two groups according to CMCs positive criteria: CMCs positive group (45 cases) and CMCs negative group (37 cases). Median age of the 82 MM patients(44 males, 38 females) was 58(range 33-78) years.30 patients with anemia but non-plasma cell related disorders from the same hospital in the corresponding period were screened into the control group. Median age of the 30 control subjects (18 males, 12 females) was 53(range 33-83) years.The flow cytometry was used to detect the proportions of CMCs and MMCs in each group. Other prognosis-associated factors such as hemoglobin (Hb), beta2-microglobulin (β2-MG), serumin albumin (Alb), serum creatinine (sCrea), serum calcium (Ca), lactate dehydrogenase(LDH), bone destruction, renal inadequacy, Durie-Salmon (DS) stage and international staging system (ISS) stage were simultaneously analyzed. Statistical methods including Kruskal-Wallis H test, Mann-Whitney U test, Spearman rank correlation, χ2 test and Logistic regression analysis were performed. Results (1) No CMCs and MMCs were detected in CR and control group. (2)The positive detection rates of CMCs in newly diagnosed and relapsed group and PR group were 71.4% and 64.5% respectively. The proportions of CMCs in both groups were positively correlated with those of MMCs (P<0.05). The proportions of CMCs and MMCs in newly diagnosed and relapsed group were apparently higher than those in PR group , and the proportions of CMCs and MMCs in PR group were apparently higher than those in CR group and control group (P<0.008 3). (3)The rates of moderate to severe anemia, elevated β2-MG, elevated sCrea, bone destruction and renal inadequacy in CMCs positive group were significantly increased as compared with CMCs negative group , which led to a higher DS and ISS stage (P<0.05). The multivariate logistic regression analysis indicated that moderate to severe anemia and elevated β2-MG were independent risk factors of the presence of CMCs (P<0.05). Conclusions CMCs could reflect the tumor load and the progression of disease in patients with MM.CMCs dete ction could improved the patients′ compliance as compared with MMCs. Moderate to severe anemia and elevated β2-MG were independent risk factors of the presence of CMCs in patients with MM.(Chin J Lab Med, 2017, 40: 267-272) Key words: Multiple myeloma; Neoplastic cells, circulating; Cell line, tumor; Flow cytometry