Immunohistology for expression of the CD3ζ and CD3ε chains in TIL was performed in 138 paraffin-embedded primary oral squamous cell carcinoma tissues and 10 nontumor, inflammatory lesions. Semiquantitative analysis of the staining intensity for ζ chain expression and number of ζ chain expression-positive cells distinguished tumors with absent or low ζ expression (42 of 132) from those with normal ζ expression (90 of 132). ζ chain expression was inversely correlated with the tumor stage. Survival was significantly lower in patients whose TIL had absent or low ζ expression, controlling for stage (P = 0.003) and lymph node status (P = 0.0005). The prognostic value of ζ chain was restricted to patients with stage III or IV tumors (P = 0.003). The data indicate that absent or decreased ζ expression in TIL combined with tumor stage or nodal status defines a group of patients with oral squamous cell carcinoma who have an extremely poor prognosis.
Supported in part by NIH Grant P01-DE 12321 (to T. L. W.).