Chronic lymphocytic leukemia with del13q14 as the sole abnormality: dynamic prognostic estimate by interphase-FISH.
This study analyzed 140 patients with isolated del13q14 on interphase FISH (I-FISH), to identify subsets with a different progression risk and to assess the acquisition of additional chromosomal abnormalities (clonal evolution) in treatment-naïve del13q14 patients. A monoallelic deletion (del13qx1) was detected in 123 cases (88%), a biallelic deletion (del13qx2) in eight and a mosaic of monoallelic and biallelic deletions (del13qx1/del13qx2) in nine. In 33% of cases, deletion encompassed the Rb1 locus The median percentage of abnormal nuclei was 50% (15%-96%), and it was higher in patients with a biallelic/mosaic pattern in comparison with patients with monoallelic deletion. Sixty two patients (44%) have been treated; 5-year treatment free survival rate was 56% and the median treatment free survival was 65 months. The baseline percentage of deleted nuclei, as a continuous variable, was related to progression (HR: 1.02; p = 0.001). According to deletion burden, three groups were identified: 64 cases (46%) had <50% deleted nuclei, 47 (33%) had 50-69% deleted nuclei, and 29 (21%) had ≥70% deleted nuclei. The 5-year untreated rate was 70.5% , 52.6% and 28.7% (p < 0.0001), respectively. In multivariate analysis using IGHV mutational status, presence of a nullisomic clone, CD38 expression and percentage of deleted nuclei as covariates, only IGHV mutational status and the percentage of deleted nuclei were independent risk factors for treatment. In 103 patients serially monitored by I-FISH before starting any treatment, we observed a significant increase in the proportion of del13q14 cells, and this increase affected the risk of subsequent treatment requirement (HR 2.54, p = 0.001). The appearance of a new clone was detected in 16 patients (15.5%) and chromosome 13 was involved in 14 of them. I-FISH monitoring proves worthwhile for a dynamic risk stratification and for planning clinical surveillance.
Department of Oncology-Hematology, Hematology Unit. Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
Ester M
EM
Orlandi
Paolo
P
Bernasconi
Cristiana
C
Pascutto
Ilaria
I
Giardini
Paola M
PM
Cavigliano
Marina
M
Boni
Silvia
S
Zibellini
Mario
M
Cazzola
D051997:ADP-ribosyl Cyclase 1 / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002467:Cell Nucleus / Q000648:ultrastructure; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D002999:Clone Cells / Q000648:ultrastructure; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D017353:Gene Deletion; D016161:Genes, Retinoblastoma; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007399:Interphase / Q000235:genetics; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy / Q000235:genetics*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D011379:Prognosis; D016016:Proportional Hazards Models; D016160:Retinoblastoma Protein / Q000172:deficiency / Q000235:genetics; D012306:Risk; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000235:genetics
D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1