Cytogenetic Evolution and Its Effect on Prognosis in Newly Diagnosed and Relapsed MM Patients

Background: In the development of MM, relapse and refractory are inevitable, and cytogenetic abnormalities (CA) may change throughout the progression. The CA at diagnosis may be different from the CA at the first or second relapse. Several studies have shown that the instability of the chromosomal in MM and its associated CA, such as 17p deletion, t (4;14) and/or t (14;16), 1q21gain, and so on, are the fundamental reasons for the heterogeneity in prognosis of patients with MM. However, little is known about the effect of changes of CA on the prognosis of people with MM.

Methods: We retrospectively analyzed 74 patients in our center who performed FISH detection both at diagnosis and first relapse since June 2013, and analyzed CA changes at the time of the diagnosis to progressive disease and the effect of CA changes on prognosis in 74 patients with MM.

Results: Among the 74 MM patients, 26 (35.1%) MM patients acquired a new CA at the first recurrence, 21 (28.4%) MM patients lost their original CA at the first relapse, and 27 (36.5%) MM patients had no change in CA at the time of diagnosis and the first relapse. The most frequently lost and gained CA were 1q21 gain and 13q deletion, respectively. Of the 21 patients who lost CA, 11 had biochemical relapse, 8 patients had solitary extramedullary relapse, and 2 had clinical relapse. 8 patients who had solitary extramedullary relapse was excluded from analysis. Only 66 patients were divided into three groups according to whether they had high-risk cytogenetics at diagnosis or the first relapse. The first group (42 cases): there was no high-risk cytogenetics at diagnosis and the first relapse (CA normal/CA normal). The second group (16 cases): no high-risk cytogenetics at diagnosis, and newly acquired high-risk cytogenetics at the first relapse (CA normal/CA high). The third group (8 cases): high-risk cytogenetics at diagnosis and at the first relapse (CA high/CA high). The results showed that there was a difference in the median OS among the three groups (p<0.001). The comparison between the groups showed that the median OS of the first group was better than that of the second and third group, and there was no difference in median OS between the second and third group (p<0.05).

Conclusion: The results of this study suggested that cytogenetic abnormalities in MM patients would change during the development of the disease. With the the development of the disease, the changes of CA had a certain influence on the prognosis. Regardless of the timing, patients with high-risk CA have a poor prognosis.

No relevant conflicts of interest to declare.