Clinical utility of a diagnostic approach to detect genetic abnormalities in multiple myeloma: A single institution experience

Background: The identification of genetic abnormalities in patients with multiple myeloma (MM) has gained emphasis because genetics-based risk stratification significantly affects overall survival (OS). We investigated genetic abnormalities using conventional cytogenetics and FISH and analyzed the prognostic significance of the identified additional abnormalities in MM. Methods: In total, 267 bone marrow samples were collected from February 2006 to November 2013 from patients who were newly diagnosed as having MM in a tertiary-care hospital in Korea. The clinical and laboratory data were retrospectively obtained. Cox proportional hazard regression was used to examine the relationship between clinical/genetic factors and survival outcome, using univariate and multivariate models. Results: Using conventional cytogenetic analysis and FISH, 45% (120/267) and 69% (183/267) patients, respectively, were identified to harbor genetic abnormalities. In the univariate analysis, the following genetic variables were identified to affect OS: abnormal karyotype (P<0.001), aneuploidy (P=0.046), -13 or del(13q) (P=0.002), 1q amplification (P< 0.001), and t(4;14) (P= 0.020). In the multivariate analysis, the presence of -13 or del(13q) was the only significant genetic factor affecting OS (P= 0.012) with a hazard ratio (HR) of 2.131 (95% confidence interval [CI], 1.185-3.832) in addition to the clinical factor of age (>65 years) (P=0.013) with an HR of 2.505 (95% CI, 1.218-5.151). Conclusions: Our findings highlight the importance of applying a comprehensive approach for detecting genetic abnormalities, which could be closely associated with the prognostic significance of MM.