Effect of Amp5q31 and Del12p13 on Survival of Patients with Multiple Myeloma Treated with Novel Agent-Based Regimens: A Single Center Experience on 172 Patients

Abstract 1811

The presence of chromosomal aberrations is a characteristic feature of multiple myeloma (MM). Recently, Avet-Loiseau et al reported that amp5q31.3 and del12p13.31, detected by high-density, single-nucleotide polymorphism arrays analysis correlate with prognosis in MM patients who were treated upfront with conventional chemotherapy (JCO 2009; 27:4585–90). The aim of our study was to evaluate the effect of these chromosomal abberations on survival of patients with newly diagnosed MM or with relapsed/refractory myeloma who were treated with novel agent-based regimens.

We studied 172 MM patients who were treated in a single center in Athens (Greece) during a 4-year period (2007–2011); 76 were newly-diagnosed and were treated upfront with either bortezomib- or IMiD-based regimens and 96 had relapsed or refractory MM and were treated with the combination of lenalidomide and dexamethasone with or without bortezomib (RD vs. VRD) based on the presence of previous peripheral neuropathy (Dimopoulos et al, Leukemia 2010;24:1769–78). A combined methodological approach of G-banding karyotypic analysis and interphase fluorescence in situ hybridization (FISH) was performed in all patients. G-banding analysis was performed according to the European Cytogenetic Guidelines and Quality Assurance (ECA, 2006). The clonality criteria and the karyotypic description followed the recommendations of the International System for Human Cytogenetic Nomenclature (ISCN, 2009). FISH was performed according to the Recommendations for FISH in MM (European Myeloma Network) on uncultured BM, either on cytoplasmic immunoglobulin-enhanced cells (cIg-FISH) or on nuclei from purified CD138+ plasma cells. Commercially available DNA probes (Abott-VYSIS) were used for the detection of del17p, del13q, add1q21, t(4;14) and t(14;16). The probes RP11-96J7 and RP11-578N7 (labeled by Empire Genomics, NY, USA) were used to detect amp5q31 and del12p13.

The frequency of the studied chromosomal abnormalities is depicted in the table. There was a strong correlation between the presence of amp5q31 with hyperdiploidy (p=0.012) but amp5q31 did not correlate with the presence of any other of the studied chromosomal aberrations. The presence of del12p13 was correlated with the presence of del13q (p=0.001), t(4;14) (p=0.009) and del17p (p=0.005). Add1q21 also correlated with del13q (p<0.001), t(4;14) (p<0.001) and del17p (p=0.007).

In patients with relapsed/refractory MM, who received either RD or VRD, the median overall survival was 19 months. Patients with amp5q31 had a median survival of 18 months (95% CI: 13–23 months) vs. 21 months of the others (95% CI: 8–35 months; p=0.737), while patients with del12p13 had a median survival of 27 months (95% CI: 0–57 months) vs. 19 months of the others (95% CI: 10–27 months; p=0.767). Of the other studied cytogenetic abnormalities, the presence of del17p (11 vs. 26 months; p=0.001), amp1q21 (12 vs. 26 months; p=0.001) and del13q by FISH (11 vs. 26 months; p=0.025), but not of t(4;14) (p=0.521), were associated with inferior overall survival.

In patients with newly-diagnosed MM, the median overall survival was 57 months. The median survival of patients with amp5q31 was 46 months vs. 57 months of all others (p=0.315) and for patients with del12p13 has not been reached vs. 57 months of all others (p=0.379).

In conclusion, amp5q31 and del12p13 are recurrent chromosomal abnormalities in MM. Amp5q31 is not associated with the presence of other genetic features, except hyperdiploidy. αmp5q31 or 12p13 was not predictive of survival ιn our series. However, further studies are needed in patients with newly diagnosed MM who receive novel agents upfront to validate the prognostic importance of amp5q31 and del12p13.