Primary cutaneous non-Hodgkin's lymphoma with aggressive histology: Inferior outcome is associated with peripheral T-cell type and elevated lactate dehydrogenase, but not extent of cutaneous involvement

Background: The aim of this study was to explore the association between extent of cutaneous involvement, presenting features and progression-free survival (PFS) in patients with primary cutaneous non-Hodgkin's lymphoma (PCNHL) of aggressive histology. Methods: Previously untreated patients with localized or extensive PCNHL of aggressive histology, treated with combination chemotherapy, but excluding lymphoblastic lymphoma and mycosis fungoides and its variants, were reviewed retrospectively. Results: We identified 53 patients, of whom 52 (35 males, 17 females) were treated with doxorubicin-based regimens. Median age was 52 years (range 25-81 years), and disease was localized and extensive in 37 and 16 patients, respectively. Twenty-four patients had diffuse large B-cell lymphoma, nine had grade 3 follicular lymphoma, 13 had peripheral T-cell lymphoma (PTCL; not otherwise specified) and seven had anaplastic large cell lymphoma (WHO classification). With a median follow-up of 101 months (range 2-237 months) for survivors, the 10-year PFS was 65 ± 7% and overall survival was 72 ± 8%. The first failure involved the skin in 33% of B-cell and 91% of relapsing T-cell lymphomas. Univariate analysis revealed that PTCL (P = 0.005), lymphopenia (P = 0.01) and high serum levels of β₂-microglobulin (P = 0.0006) and LDH (P = 0.002), but not extent of skin involvement, were associated with inferior PFS. Multivariate analysis revealed that only PTCL and high serum lactate dehydrogenase (LDH) were independently associated with inferior PFS. Conclusions: PTCL and elevated serum LDH level, but not extent of cutaneous involvement are associated with inferior PFS in aggressive PCNHL treated with combination chemotherapy.