Nuclear Area Predicts Outcome In Peripheral T-Cell Lymphoma, Not Otherwise Specified: Morphometric Image and Immunohistochemical Analyses of 78 Patients

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is an uncommon tumor with unfavorable prognosis. The purpose of this retrospective study was to investigate the cytological features and treatment outcomes in patients with PTCL-NOS and to obtain new information on the therapeutic implications of PTCL-NOS.

A total of 6 institutions in Japan and Asia submitted clinical and pathologic information on PTCL-NOS diagnosed and treated at their respective centers. Among these cases, 55 (71%) were from Japan, 8 (10%) were from Hong Kong, 8 (10%) were from Thailand, and 7 (9%) were from Korea. From 1992 to 2006, 78 cases of PTCL-NOS were examined for cytological features, focusing on morphometric image analysis. The average nuclear area of lymphoma cells, as well as the median, the minimum, the maximum and the standard deviation, was estimated in 50 cells for each case. In addition, we performed an immunohistochemical study of CCR4 expression in all cases. Univariate analyses were performed using Kaplan-Meier survival estimates, and data were compared using the log-rank test. Cox proportional-hazard regression test was used for multivariate analysis. P-values of less than 0.05 were considered significant.

Clinical information was available for review in 78 cases. There was a 1.52:1 male/female ratio, and median age was 62 years (range, 3 to 87 years). Sixty-two percent of patients had advanced clinical stages. Lactic dehydrogenase (LDH) was elevated in 53% of cases, and most patients were treated with combination chemotherapy. Median survival was 693 days. On the morphometric image analysis, median nuclear area was 41.7 μ m² (range, 22 to 119 μ m²). Thirty-three of the cases (42%) showed positive CCR4 immunostaining. Statistical analysis confirmed that nuclear area of lymphoma cells in PTCL-NOS is correlated with overall survival, whereas immunohistochemical expression of CCR4 is not correlated with overall survival or nuclear area of lymphoma cells. Multivariate analysis confirmed that the nuclear area of lymphoma cells in PTCL-NOS is an independent prognostic factor.

These results indicate that nuclear area of lymphoma cells in PTCL-NOS is an independent prognostic factor that may predict overall survival. Because PTCL-NOS is a heterogeneous disease with regard to histological type and pathological state, nuclear area of lymphoma cells could be used to stratify patients with PTCL-NOS for therapies, although we are continuing to accumulate data.

No relevant conflicts of interest to declare.