A Multicenter Real-World Analysis (RWA) of Primary Cutaneous Anaplastic Large Cell Lymphoma (PCALCL) Treated in the Modern Era
Authors: Jagadeesh Deepa , Barta Stefan K. , Brammer Jonathan E. , Wei Wei , Chang Julie E , Mishra Rahul , Montreh Tavakkoli , Habib Alma , Watkins Marcus P , Deshmukh Yash , Macapagal Sharina C , Iqbal Madiha , Bennani N. Nora , Lansigan Frederick , Mehta-Shah Neha 
Published: December 2023

Introduction:
The real-world outcomes in patients (pts) with PCALCL in the era of targeted therapies like Brentuximab Vedotin (BV) is not well defined due to lack of large multicenter studies. We conducted a multicenter retrospective RWA to assess patient and disease characteristics, treatment patterns, survival outcomes and impact of novel therapies in this rare type of cutaneous T cell lymphoma (CTCL).
Methods:
A total of 95 adult (≥18 years) pts from 8 academic institutions in the United States diagnosed from 2010-2022 were included in the analysis. The study was approved by the Institutional Review Boards at the respective sites. Demographic and disease factors were summarized by descriptive statistics. Overall survival (OS) was estimated by Kaplan-Meier method and compared using log rank method.
Results:
In our cohort, the median age at diagnosis was 63 (range 18-93) years. The majority of pts were male 60%, white 79%, and had good performance status (PS) ECOG 0-1 (93%). Median time from initial presentation to diagnosis was 1.8 (range 0-211) months. Most common initial skin presentation was tumor 46% (44/95), followed by plaques 27% (26/95) and patches 15% (14/95). No pt presented with erythroderma. Median size of the largest lesion was 2 (range 0.5-20) cm. 63% had early stage (IA-IIA) disease and 86% had &lt;5 skin lesions at the time of initial diagnosis. Furthermore, palpable lymph node (LN) (10%) and elevated LDH (18%) were uncommon at diagnosis.
Initial treatments include localized radiation 60%, surgical excision 21% and topical steroids 11%. A small subset of pts received systemic treatments like CHOP 13% (12/95), BV 8% (8/95) and oral methotrexate 7% (7/95) as frontline therapy. A proportion of pts received XRT with CHOP (6/12) and BV (2/8). The overall response rate (ORR) to initial therapy was 68% (65/95) with 61% achieving a CR and 17% had primary refractory disease (stable and progressive disease). Relapse rate after 1st line therapy was 52% (49/95). In our cohort a total of 22 pts received BV after frontline therapy, of which 19 were BV naïve and 3 were re-treated. At the time of last follow up, 27% of our cohort were still on treatment, 78% were alive and 21% were dead; only 3% of deaths were attributed to the lymphoma. The median OS was 128 months (95% CI: 78.4-NA) (Figure 1) with a median follow up of 42 (range 0.5-123.5) months. The 5-year OS was 77%. On univariate analysis, older age (≥65 vs &lt;65 years) (median OS 78 vs 128 months; p=0.004) and higher number of lesions (5-10 vs &lt;5) (mOS 34 vs 128 months; p=&lt;0.0001) were significant associated with OS (Table 1). Type and size of the skin lesions, presence of palpable LN, elevated LDH, stage, and treatment modalities had no impact on OS. Results of multivariate analysis will be presented at the conference.
Conclusion:
In this large multicenter RWA of PCALCL, excellent long-term survival was observed following frontline therapies that were mostly skin directed. The use of systemic therapies including BV were infrequent even in relapsed disease. Older age and increased number of skin lesions were associated with poor OS.