[The impact of renal function on prognostic value of β₂-microglobulin of ISS stage system in multiple myeloma patients--Clinical data analysis of 666 patients in a single center]

Objective: To investigate the influence of renal function on the level of β₂-microglobulin (β₂-MG) as prognostic factor in newly diagnosed multiple myeloma (MM) patients, and to analyze the overall survival (OS) in different level of β₂-MG with relatively normal or abnormal renal function in MM patients.

Methods: According to the level of β₂-MG, 666 newly diagnosed MM patients were divided into three groups as β₂-MG<3.5, 3.5-<5.5, ≥5.5 mg/L. According to the level of serum creatinine, these patients were divided into two groups:serum creatinine <177 μmol/L as relatively normal group, serum creatinine ≥177 μmol/L as abnormal group.

Results: Among 666 patients, there were 416 male and 250 female, the median age was 58 (25-86) years old. Comparison of OS among β₂-MG<3.5, 3.5-<5.5, ≥5.5 mg/L groups indicated that the median OS of the three groups were 85.75 (95% CI 70.99-100.50), 47.25 (95% CI 40.98-53.53) and 35.05 (95% CI 30.75-39.35) months, respectively (P<0.01). Comparison of OS between serum creatinine <177 and ≥177 mmol/L groups, the median OS of the two groups were 64.67 (95% CI 56.57-72.77) and 32.74 (95% CI 27.74-37.73) months, respectively (P<0.01). In β₂-MG≥5.5 mg/L, the median OS of relatively normal and abnormal groups were 37.25 (95% CI 31.45-43.06) and 32.55 (95% CI 26.26-38.83) months, respectively (P=0.142).

Conclusion: High level of β₂-MG and renal function correlated with shorter survival of MM patients. Higher level of β₂-MG with abnormal renal function can't change the prognostic value of β₂-microglobulin on MM.