Immunohistochemical expression of p53, bcl-2, and p21waf1 in 48 Argentinean children with non-Hodgkin lymphoma.

CHABAY P; DE MATTEO E; PRECIADO MV

APPLIED IMMUNOHISTOCHEMISTRY

Lippincott Williams & Wilkins,

Año: 2006 vol. 14 p. 12 - 17

1062-3345

BACKGROUND: Lymphoma accounts for 10% of all childhood cancers in developed countries. In Argentina, the incidence is 13.6%; of these, 53% are non-Hodgkin lymphomas (NHL) and 47% are Hodgkin lymphomas. Overexpression of p53, p21, and bcl-2 has been studied mainly in adults with NHL and correlated with clinical features and survival. The authors´ aim was to analyze overexpression of these cellular oncogenes in children with NHL. METHODS: Formalin-fixed paraffin-embedded lymph node biopsies from 48 children with NHL were studied by immunohistochemistry with monoclonal antibodies for p53, bcl-2, and p21. RESULTS: Overexpression of p53 was detected in 81% of cases; bcl-2 positivity was 46% and p21 positivity was 42%. The p53/p21 expression patterns (types IV and V patterns), which correspond to the overexpression of nonfunctional p53, accounted for 46% of NHL. None of the studied oncogene patterns correlated with poor clinical patient outcome or histologic subtype. CONCLUSIONS: Of 81% of cases with p53 overexpression, 46% exhibited a nonfunctional p53 pattern, and this may contribute to dysregulation of proliferation, bcl-2 expression in up to 46% of cases may reflect a failure of bcl-2 downregulation in pre-B and immature B cells.