1. Influence of gene polymorphism BCL-2+ and MYC+ determined by FISH on the prognosis of patients with diffuse large B cell lymphoma treated by immunochemotherapy
- Author
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Sretenović, Snežana S., Mitrović, Slobodanka, Knežević, Milan, Mihaljević, Biljana, Jovanović, Ivan, and Đukić, Aleksandar
- Subjects
FISH ,s- myc ,bcl-2 ,internacionalni prognostički indeks (IPI) ,Diffuse large B cell lymphoma ,MYC ,Difuzni B Krupnoćelijski Limfom ,International Prognostic Index - Abstract
Difuzni B krupnoćelijski limfom kao najčešći tip nehočkinskih limfoma, čini heterogenu grupu oboljenja sa višestrukim genetskim abnormalnostima. Posebno su značajna oštećenja gena koji učestvuju u kontroli ćelijskog ciklusa i apoptozi. Udruženost bcl-2/c-myc genskog preuređenja, čini oko 60% Double-Hit limfoma, bez mnogo podataka o prognostičkom značaju. Ciljevi ove studije bili su da se FISH-om ispita uticaj genskog polimorfizma bcl-2+ i c-myc+ na terapijski odgovor, kao i da se ispita mogućnost da se prema internacionalnom prognostičkom indeksu (IPI) selektuju bolesnici za testiranje čime bi se individualizovao terapijski pristup. Rezultati studije su pokazali da genski polimorfizam bcl-2+ i c-myc+, pojedinačan i udružen, ne utiče značajno na preživljavanje, međutim pokazuje lošiji odgovor na terapiju u odnosu na myc- i bcl-2- DBKL. Postoji razlika u učestalosti bcl-2+ i myc+ u odnosu na IPI (visok IPI 47,2% i 36,1% vs nizak IPI 38,5% i 46,2%) ali bez statističke značajnosti. Uporedna analiza prognostičkog značaja dvostrukih mutacija i IPI skora ne pokazuje uticaj na preživljavanje ni kod ispitanika sa niskim rizikom, niti kod ispitanika sa visokim IPI rizikom. U grupi bcl-2+ i c-myc+ ispitanika sa niskim IPI rizikom, jednogodišnje preživljavanje bilo je 83,3%, dvogodišnje 66,7% i bez promene na kraju perioda praćenja od 7,5 godina. Kod bcl-2+ i s-myc+ ispitanika sa visokim IPI rizikom, preživljavanje posle godinu dana iznosilo je 28,6%, posle dve godine 14,3%, dok niko od obolelih iz ove grupe nije živeo duže od tri godine. Ispitanici refrakterni na terapiju imali su značajno kraće preživljavanje od ispitanika koji su imali bilo kakav odgovor na primenjeno lečenje, niko iz ove grupe ispitanika nije živeo duže od 33 meseca. Statističkom analizom nije utvrđena korelacija postojanja genskih mutacija i refrakternosti na terapiju u ovoj studiji. I u slučaju predikcije refrakternosti na terapiju dobijene vrednosti senzitivnosti (0,462) i specifičnosti (0,592) ukazuju na mali značaj prisutne bcl-2+ i c-myc+. Multivarijantnom Cox-ovom analizom kao nezavisni faktori od uticaja na preživljavanje pokazali su se: ECOG, kompletna remisija, refrakternost na terapiju, CRP i bcl-2 pozitivnost utvrđena imunohistohemijski, i to nezavisno od prisustva drugih faktora. Sumarno, rezultati ovog istraživanja su pokazali da postojanje bcl2+ i s-myc+, utvrđene FISH analizom, ni pojedinačno ni udruženo, ne pokazuju uticaj na ukupno preživljavanje, kao ni da IPI ne može biti prediktor opredeljenja za testiranje bolesnika na genski polimorfizam. Dobijeni rezultati sugerišu da postoji istovremeno više mehanizama koji uslovljavaju da jedna trećina bolesnika ima lošu prognozu i pored primenjene imunohemioterapije, zbog čega se rezultati genskih analiza bcl-2 i c-myc, moraju korelirati sa kliničkim, histomorfološkim i imunohistohemijskim informacijama. Diffuse large B cell lymphoma, as the most common type of non-Hodgkin´ s lymphomas, constitutes a heterogeneous groups of diseases with multiple genetic abnormalities. Damages of genes involved in cell cycle control and apoptosis are of particular importance. Association of bcl-2/c-myc gene rearrangement, constitutes about 60% of Double-Hit lymphoma, without a lot of data on prognostic importance. The aims of this study were to FISH analysis the impact of gene polymorphism bcl-2+ and c-myc+ on the therapeutic response as well as to investigate the possibility that the International Prognostic Index (IPI) selects patients for testing to individualized therapeutic approach. The study results showed that the genetic polymorphism of bcl-2+ and c-myc+, both individual and associated, does not significantly affect survival rate, however, it indicated poorer response to therapy compared to myc- and bcl-2- DLBCL. There is a difference in incidence of bcl-2 and c-myc+ compared to the IPI (IPI high 47.2% and 36,1% vs 38,5% IPI low and 46,2%), but without statistical significance. Comparative analysis of the prognostic significance of the double mutation and the IPI indicated no impact on survival neither in patients with a low risk, nor in patients with a high risk IPI. In the group of bcl-2+ and c-myc + of the exeminees with a low IPI risk, one-year survival was 83,3%, two-year long was 66,7% without changes at the end of follow-up period of 7,5 years. In bcl-2 + and c-myc + examinees with high IPI risk survival after one year was 28,6%, after two years of 14,3%, whereas none of the patients in this group lived longer than three years. Respondents refractory to therapy had a significantly shorter survival than those who had any kind of response to the treatment, none of these groups of patients lived longer than 33 months. Statistical analysis showed no correlations existence of genetic mutations and refractory response to the therapy in this study. And in the case of predicting refractory response to the therapy obtained values of sensitivity (0,462) and specificity (0,592), indicate the importance of a small present of bcl-2+ and c-myc+. Multivariate Cox's analysis as independent factors influence the survival proved: ECOG, complete remission, refractory to therapy, CRP and bcl-2 positivity was determined by immunohistochemistry, and irrespective of the presence of other factors. In summary, the results of this study showed that the presence of bcl-2 and c-myc+ , confirmed by FISH analysis, either individually or jointly, showed no impact on overall survival, or that the IPI could be a predictor of commitment to testing patients with the genetic polymorphism. The results suggest that there are several parallel mechanisms that require that one-third of patients have a poor prognosis despite immunochemotherapy applied, which is why the results of genetic analysis of bcl-2 and c-myc must correlate with clinical, immunohistochemical and hystomorphologic information.
- Published
- 2015