[Prognostic value of 1q21 amplification in multiple myeloma]

To determine the prevalence of amp1q21 and its relationship to the clinical manifestations of multiple myeloma (MM).

In December 2009 to March 2016, a total 134 patients aged 30 to 81 years (median 57 years) underwent a pretreatment FISH-study of bone marrow (BM) with centromeric and locus-specific DNA probes to identify amp1q21, t(11;14), t(4;14), t(14;16), t(14;20), t(6;14), trisomies of chromosomes 5, 9, 15, del13q14, del17p13/TP53, and t(8q24)/cMYC. Induction therapy with bortezomib-containing cycles was performed. Autologous stem cell transplantation was carried out in 48 patients. The median follow-up of patients was 19.3 months (3.2-77.4 months). Disease progression was diagnosed in 69 (51.5%) patients; 12 patients also underwent FISH study during disease progression.

At the onset of MM, amp1q21 was detected in 53 (39.6%) patients. The overall 5-year survival rate in patients with amp1q21 was almost 2 times lower than that in those without amp1q21 (43.5 and 79.4%, respectively; p=0.07). The overall 5-year survival rate in patients with one extra copy of 1q21 (only 3 copies) was 67.3%, that in those with 2 or more extra copies of 1q21 (only 4-7 copies) was 20.9% (p=0.0016). Nine (75%) of the 12 patients examined during disease progression were found to have amp1q21: 2 cases were detected in the period of progression to have amp1q21 in its absence at disease onset; 7 cases had amp1q21 both at MM onset and progression; however, the number of copies of 1q21 was unchanged.

Аmp1q21 is one of the most common chromosomal abnormalities in patients with new-onset MM and may appear in the course of disease progression. The presence of аmp1q21 is an important prognostic factor and must have to be included in the diagnostic study both at disease onset and progression.