Gamma-delta T-cell phenotype is associated with significantly decreased survival in cutaneous T-cell lymphoma

The importance of αβ versus γδ T-cell subset antigen expression in the classification of peripheral T-cell lymphomas is still unclear. The objective of this study was to investigate the prognostic value of T-cell receptor–δ1 (TCRδ1) expression in primary cutaneous T-cell lymphomas. TCRδ1 cellular expression was assessed in skin biopsy specimens of 104 individuals with cutaneous T-cell lymphoma by immunohistochemistry. Both univariate (Kaplan-Meier) and multivariate (Cox regression) analyses were conducted to determine which variables (T-cell subtype, hemophagocytosis, histologic profile, age, sex, and adenopathy) were significantly associated with survival. Univariate analysis indicated that there was a statistically significant difference in survival between the patients with αβ cutaneous T-cell lymphoma and patients with γδ cutaneous T-cell lymphoma (P < .0001). There was also a statistically significant decrease in survival among patients who had subcutaneous involvement compared with patients who had epidermotropic and/or dermal involvement (P < .0001). Cox model analysis indicated that TCRδ1 expression was the factor that was most closely associated with decreased survival (P < .0001). Among those patients with cutaneous γδ T-cell lymphoma (n = 33), there was a trend for decreased survival for patients who had histologic evidence of subcutaneous fat involvement in comparison with patients who had epidermotropic or dermal patterns of infiltration (P = .067). No other prognostic factors were identified as having a notable association with outcome in this subgroup. TCRδ1 expression in primary cutaneous lymphomas is an independent prognostic factor associated with decreased survival.