T-cell non-Hodgkin's lymphoma in adults: clinicopathological characteristics, response to treatment and prognostic factors.

T-cell NHL represent 10-15% of all malignant lymphomas making systematic prospective clinical trials difficult. Therefore, the prognostic significance of the T-cell phenotype has been a matter of controversy in recent years. In a retrospective analysis of 681 patients (pts) with NHL accrued from 1992 to 1997 at a single institution, 66 patients with T-cell NHL were identified. According to the REAL classification, histologies were as follows: 28 peripheral T-cell lymphomas (PTCL), 19 large cell anaplastic lymphoma (LCAL), 12 precursor lymphoblastic lymphoma (Lb), and seven AILD. Multiagent anthracycline containing regimens were used as initial therapy in 91% of cases. T-cell NHL represent 9.8% of all NHL patients at our institution accrued over a 6-year period. Overall response rate was 76%, 21% had progressive disease and 3% died during first line treatment. Mean overall survival (OS) was 8.22 +/- 0.94 years. There was a significant difference in OS between the four different histological subgroups (log rank P=0.0288). LCAL: mean OS 11.05 +/- 1.55 years (95% CI 8.00-14.09); LB: mean OS 7.09 +/- 1.40 years (95% CI 4.33-9.84); PTCL: mean 6.62 +/- 1.17 years (95% CI 4.33-8.90); AILD: 1.54 +/- 0.44 years (95% CI 0.67-2.40). OS was also significantly different for patients classified according to the International Prognostic Index (IPI)-score (log rank P = 0.002). Mean OS for patients with low risk, intermediate low risk, intermediate high risk and high risk was 10.46 +/- 1.02, 6.46 +/- 1.79, 4.50 +/- 1.20 and 1.15 +/- 0.46 years, respectively. Univariate analysis (log-rank test) for prognostic factors also revealed elevated LDH, B-symptoms and extranodal involvement as significant factors for OS. The presence of bulky disease (>7.5 cm), advanced stage III/IV and bone marrow involvement did not influence OS. In conclusion, it is evident that histological subtype and IPI-score have a strong prognostic impact on OS in pts with T-cell NHL. Thus, the distribution of risk factors in patients with T-cell NHL may be more important for OS than T-cell histology per se.