The impact of trisomy 12, retinoblastoma gene and P53 in prognosis of B-cell chronic lymphocytic leukemia.

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The impact of trisomy 12, retinoblastoma gene and P53 in prognosis of B-cell

chronic lymphocytic leukemia.

M AbdelSalam, A El Sissy, MA Samra, S Ibrahim, D El Markaby, and F Gadallah

Hematology, June 1, 2008; 13(3): 147-53.

Clinical Oncology Center, Cairo University Hospital, Cairo University, Cairo,

Egypt.

PURPOSE: Routine cytogenetic analysis frequently fails to identify an abnormal

clone in B-cell lymphocytic leukaemia (B-CLL) due to poor response to mitogen

stimulation. Fluorescence in situ hybridization (FISH) suggest that chromosomal

abnormalities occur more frequently, most commonly trisomy 12, retinoblastoma

gene deletion (Rb1 gene) and P53 gene deletion. PATIENTS AND METHODS: 30

patients with B-CLL were enrolled in the trial from two centers in Cairo, Egypt

during the period May 2000 to January 2002. Karyotyping and FISH assessment for

possible chromosomal abnormalities (trisomy 12, Rb1 gene and P53 gene) were done

at initial diagnosis. Results of cytogenetic abnormalities were correlated with

clinical picture and survival. RESULTS: The median age was 57.4 years (range

40-75). Karyotyping technique showed that no metaphase could be detected in 30%,

metaphase with normal karyotyping was observed in 63% and cytogenetic

abnormalities were detected in two cases (one trisomy 12 and one deletion in

chromosome 13). FISH examination of interphase and metaphase nuclei revealed

cytogenetic abnormalities in 15 cases (50%), trisomy 12 in 9 (30%), Rb1 gene

deletion in 5 (17%) and P53 gene deletion in 3. At diagnosis, patients with

trisomy 12 were significantly associated with advanced stage and absolute

lymphocyte count of >or=30,000/mm(3). Univariate analysis showed that absolute

lymphocyte count >or=30,000/mm(3) (p=0.004) and trisomy 12 (p=0.024) were

associated with poor progression free survival. CONCLUSION: Interphase and

metaphase FISH studies improve the cytogenetic diagnosis of chromosomal

abnormalities in B-CLL. Lymphocytosis and trisomy 12 may be a good indicator of

poor prognosis.

PMID: 18702872