The clinical characteristics and prognosis of IGH deletion in multiple myeloma

Objective: To analyze the frequency, clinical characteristics, and prognosis of IGH deletion in multiple myeloma (MM).

Methods: A total of 310 consecutive patients with multiple myeloma were analyzed. Among them 251 patients were newly diagnosed and 59 patients were previously treated, fluorescence in situ hybridization (FISH) with IGH break apart probes were done for each case. Patterns of IGH deletion, response rate, overall survival, and progression free survival were analyzed.

Results: Several patterns of IGH deletion were identified, including monoallelic deletion of whole locus of IGH, monoallelic deletion of 3' IGH, monoallelic deletion of 5' IGH, biallelic deletion of 3' IGH deletion, and complicated deletions with various types. The incidence rate of IGH deletion was 22.7% (57/251) in newly diagnosed patients and 27.2% (16/59) in previously treated patients, no significant difference was found between the two groups (p=0.375). IGH deletion was associated with κ light chain M component (p<0.001), 13q deletion (p=0.006), and absence of t(4; 14)(p=0.033). In the cases with 13q deletion, the frequency of IGH deletion is 3.5% (1/28) in patients with t(4;14) and 40.5% (32/79) in patients without t(4;14), significant difference was found (p=0.006). We further analyzed the response rates of patients with IGH deletion who received a uniform induction regimen of PAD composing of bortezomib, epirubicin, and dexamethasone. Overall response rate (ORR) in patients with IGH deletion was better than that in patients without IGH deletion (87.5 vs. 73.6%, p<0.001), while no significant difference was found in survival analysis, either OS or PFS (p=0.158 and p=0.177, respectively).

Conclusion: IGH deletion is frequent in multiple myeloma, the incidence rate was higher in patients with 13q deletion and without t(4;14). Patients with IGH deletion had better ORR to PAD induction therapy, while it has no influence on the prognosis of multiple myeloma.