Peripheral T-Cell Lymphomas in Spain: Profiling Clinical, Phenotypic and Genetic Characteristics in Spanish Population

Purpose

The objective of this study was to investigate clinicopathologic features and prognostic factors of patients diagnosed with PTCL in 13 sites across Spain.

Patients and Methods

A multicenter, retrospective study was carried out between September 2015-November 2017.Medical charts of patients diagnosed with PTCLs between January 2008 and December 2013 that have signed the approved informed consent form were reviewed. PTCLs were then classified according to the 2016 revision of the WHO classification of lymphoid neoplasms. Clinical characteristics,history, standard immunohistochemistry (IHC) data, International Prognostic Index (IPI) and Prognostic Index for T-cell lymphoma (TCL) (PIT) were also assessed. Medians (range), mean (standard deviation) and frequency as the number of patients (n) and percentages (%) with confidence intervals at 95% (CI95%) were calculated. Overall Survival (OS) and Progression Free Survival (PFS) were analyzed using the Kaplan Meier method.

Results

175 (88.4%) patients were successfully analyzed, the male/female ratio was 1.7:1.0, and the median age was 67.2 years (range: 24.8 years -95.8 years). ECOG performance status >1 was reported for 31.9% patients. Ann Arbor stages were III and IV 27.4% and 45.7%, respectively, and LDH levels were elevated to 92 patients (52.6%). Those with B symptoms accounted for 39.4%, while soft tissue was the most frequent location (23,7%) among the 76 patient with extranodal disease; bone marrow infiltration was confirmed in 18.3% patients.

Relevant clinical antecedents related to immunological aspects were also frequently reported, including previous neoplasia (18.9%), autoimmune disease (16%), immunosuppressive treatments (7.3%) and previous viral diseases (HIV, HBV or HCV, 5.7%, 4.6% and 7.4%, respectively).

Most patients presented with angioimmunoblastic TCL (31.4%); similar proportions of patients were observed among nodal PTCL with TFH phenotype (13.1%, PTCL not otherwise specified (12.0%) and extranodal NK/TCL nasal type (11.4%). CD30 expression and staining pattern (ranged 1-4) allowed the stratification of patients according CD30 intensity (n= 121; weak: 35, moderate: 57, and intense: 29); Patients were also classified based on CD30 expression considering the median value of quantitative CD30 in our sample (15%) the cut-off point: n=132; Negative <15%: 64; Positive, ≥15%: 68).

First-line treatment with a CHOP/CHOP-like regimen was the most common finding (69.7%). Best response was observed after a median of 4 months since the start of first-line treatment (range 0.0 months - 65.2 months). Overall response rate after first-line treatment was 66.9%, with 61/151 patients reaching complete response (CR).

Median PFS (n=157) and OS (n=175) of this series were 7.87 months (CI95%: 4.98 months-10.75months) and 15.77 months (CI95%: 10.23 months -21.30 months), respectively. Overall, IPI and PIT scores influenced the PFS and OS (p<0.001). A higher number of adverse factors was associated with a shorter survival.

Reaching a CR was associated with a better PFS (CR: 62.6m; CI95%: 20.2 months -105.1 months) than the rest of patients (3.97m: CI95%: 3.08 months -4.85m; p<0.001). Response was also associated with OS; patients with CR showed an average OS of 67.01 months (CI95%: 58.2 months -75.9 months) that were significantly longer than that of patients with No-CR (median: 7.34 months; CI95%: 5.85 months -8.83 months; p<0.001).

Conclusion

This is the largest series of T cell Lymphoma reported in Spain and has allowed the description of distribution of PTCL subtypes, analyzed through central hematopathologists reanalysis and reclassification of samples from 175 PTCL patients, according to the WHO 2016 classification of lymphoid neoplasms.

Our data confirm the poor prognosis of these patients, as well as the impact of prognostic indexes and the response to first line treatment on their outcome.