Presence of cutaneous lesion is a poor prognostic factor in patients with smoldering-type adult T-cell leukemia-lymphoma

Background Prognosis of indolent types of adult T-cell leukemialymphoma (ATL) including the smoldering type was recently reported to be poorer than that shown in previous studies. Prognostic factors of smoldering-type ATL have not been defined. Cutaneous-type, which is defined as cases of smoldering type predominantly involve skin with or without peripheral blood involvement has been proposed as a distinct clinical subtype. Prognosis of cutaneous-type ATL was reported to be poorer than that of smoldering-type without cutaneous involvement. Aim To determine prognostic factors for survival and disease progression of smoldering-type ATL. Patients Thirty-one patients with smoldering-type ATL including 21 with cutaneous lesion. Methods Multivariate Cox proportional hazards model was used to identify variables associated with survival and disease progression. Peripheral blood abnormal lymphocytes (<5% vs ≥5%), serum lactate dehydrogenase (normal vs high), albumin level (<4 vs ≥4 g/dl), and cutaneous lesion (none vs present) were used as variables. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method and compared using the log-rank test. Results In the multivariate analysis, presence of cutaneous lesion was the significant prognostic factor for PFS (hazard ratio, 8.69; 95% confidence interval, 1.4-54.0; P = 0.02). Peripheral blood abnormal lymphocytes, serum lactate dehydrogenase, or albumin level was not significant. None of the variables was significantly associated with OS in the multivariate analysis. OS (P = 0.117) and PFS (P = 0.089) of the patients with cutaneous lesion were worse as compared to those of the patients without cutaneous lesion, though statistically not significant. Conclusions In this study we confirmed that presence of cutaneous lesion is an independent prognostic factor in patients with smoldering-type ATL. Cases of smoldering-type with cutaneous lesion should be classified as cutaneous-type ATL irrespective of the peripheral blood involvement.