Determinants of survival in primary cutaneous anaplastic large cell lymphoma (pcALCL): Analysis of a real-world pooled database

Abstract Background: Primary Cutaneous Anaplastic Large Cell Lymphoma (pcALCL) is a rare subtype of primary cutaneous T-cell lymphoma. While pcALCL generally exhibits an indolent clinical course with favorable prognosis, a subset of cases may demonstrate aggressive behavior, recurrence, or extracutaneous spread. Due to its rarity and clinical overlap with other CD30-positive lymphoproliferative disorders, the prognostic impact of various clinical and pathological factors is not fully understood. This exploratory analysis aims to identify demographic patterns and determinants of survival in this rare malignancy. Methods: To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, prognostic factors, and survival, we compiled a pooled database of real-world cases that satisfy the diagnostic criteria for pcALCL. Cases where pcALCL coexisted with LYP or MF were excluded. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS). Results: A total of 189 patients with confirmed pcALCL were identified. The median age was 55 with slight male preponderance (M:F 1.6). The median duration of symptoms prior to diagnosis was 2.5 months. The majority occurred on the face (43%) followed by the trunk (20%) and lower extremities (19%). Seventy-two percent were ALK-, 6% DUSP22+, and 49% recurred (77% cutaneous). Sixty-three percent were T1N0M0. The median OS and Time to First Recurrence (TTFR) were 156 and 36 months, respectively. HIV+, immunosuppression, ALK-, multiple lesions, ulceration and necrosis, response <CR, recurrence, and systemic recurrence were statistically detrimental to OS. In patients with ALK-, DUSP22+ was associated with better DFS and OS. Time to first recurrence correlated positively with OS (r= 0.70; p<0.001). OS was not impacted by sex, age, time to diagnosis, EBV status, stage, or small variant histology. Lymph node involvement and multiple lesions had worse TTFR. Upfront spontaneous regression was associated with numerically worse OS, DFS, and TTFR, but did not reach statistical significance. Compared to no treatment, OS was increasingly better with Radiation, Chemotherapy, surgery, and combined modalities (p=0.002). Conclusions: This pooled analysis reveals that while primary cutaneous anaplastic large cell lymphoma (pcALCL) generally has a favorable prognosis, specific clinicopathologic factors significantly impact survival and recurrence. It identifies the clinical, immunohistochemical, and treatment modalities that are major determinants of OS in this rare disease. These findings provide valuable insights into the prognostic determinants and optimal management strategies for pcALCL.