Deletions of the long arm of chromosome 6 in multiple mieloma patients. Association with prognostic factors

FLAVIA STELLA; MIGUEL GONZÁLEZ; ESTELA PEDRAZZINI; IRMA SLAVUTSKY; MARINA JIMÉNEZ

Mar del Plata

Congreso; LVIII Reunión Annual de la Sociedad Argentina de Investigación Clínica; 2018

Sociedad Argentina de Investigación Clínica

Multiple myeloma (MM) is a malignancy of mature plasma B cells. In this pathology, classical parameters are not accurate enough to predict the outcome of patients at early-stage disease. Nowadays, the genetic profile of tumor cells is one of the most relevant prognostic factors that could contribute to the identification of different risk groups. Chromosome unbalances, are common events, being the most frequent gains on 1q, 19p and 9q and losses on 1p, X, 13q, 14q, and 6q. We investigated the impact of deletions of the long arm of chromosome 6 (del6q) in MM patients. Results were correlated with clinical parameters and overall survival (OS). A total of 150 bone marrow samples of newly diagnosed patients were studied: 89 (59.3%) cases with structural abnormalities (SA) and 61 (40.6%) with normal karyotype (NK). Among the SA group, 35 samples showed del6q (39.3%) (17 with complex karyotype; CK), and 54 (60.7%) with other alterations than del6q (19 with CK). Clinical parameter comparisons showed that all patients with del6q (with simple or CK) showed increased levels of creatinine (p=0.0378) and beta2 microglobulin (B2M) (p=0.0039) with respect to NK group. A higher percent of cases with kappa light chain, bone marrow infiltration and lytic bone lesions was detected in cases with del6q with respect to those with NK (p=0.0022, p=0.0004 and p=0.0364, respectively). No significant differences in OS were found between cases with del6q as the only abnormality (87.7 months) respect to those with NK (123.7 months). However, a significant short OS (28.4 months) for patients with CK and del6q, was found (p=0.0021). Our data showed the association of del6q with adverse prognostic factors, but without clinical impact by itself, supporting the importance of genomic complexity in MM clinical evolution.