Prognostic significance of Fas expression in retinoblastoma.
OBJECTIVE
The loss of Fas is believed to enhance metastatic spread in diverse human tumors. We studied the expression of Fas by immunohistochemistry in retinoblastomas and correlated the results clinicopathologically.


METHODS
Archival specimens of 76 retinoblastomas were included in this study. The tumors were divided into three groups: Group A (n = 21) comprising tumors with no invasion; Group B (n = 46) tumors with invasion of choroid (diffuse), optic nerve (post-laminar), and orbit; and Group C (n = 9) tumors with both invasion and metastasis. Sections were immunostained with monoclonal antibody CD95 (APO-1/Fas) and the immunoreactivity was assessed.


RESULTS
Negative immunoreactivity of Fas was observed in Group B and Group C tumors (p < 0.001). Poorly differentiated retinoblastomas showed a decreased Fas expression (p = 0.006).


CONCLUSIONS
Decreased expression of Fas is seen in aggressive tumors and tumors that are poorly differentiated. This preliminary observation deserves further investigation, which may then shed more light on the immune escape mechanisms of this tumor and thus enable novel therapeutic strategies.
Shanmugam
Mahesh P
MP
Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Lakshmi
Amirtha
A
Biswas
Jyotirmay
J
Krishnakumar
S
S
D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D009361:Neoplasm Invasiveness / Q000473:pathology; D011379:Prognosis; D019572:Retinal Neoplasms / Q000378:metabolism* / Q000473:pathology; D012175:Retinoblastoma / Q000378:metabolism* / Q000473:pathology / Q000556:secondary; D013194:Staining and Labeling; D019014:fas Receptor / Q000378:metabolism*
D019014:fas Receptor