Abstract 877P
Background
Malignant cutaneous adnexal tumors (MCATs) comprise a heterogeneous group of rare neoplasms. Little is known about their natural history, with limited information regarding prognostic factors and long-term outcomes described.
Methods
In this single-center retrospective cohort study, we included patients diagnosed with MCATs between 2014 and 2021. Clinicopathologic variables and outcome measures were analyzed. X2, Fisher’s exact and Mann-Whitney U tests were used to compare groups and Cox proportional hazards models were fitted. The log-rank test was used to assess recurrence free survival (RFS) and overall survival (OS).
Results
We identified 114 patients with MCATs. Characteristics are displayed in table. The most frequent histological subtypes were porocarcinoma in 41 (36%), sebaceous carcinoma in 28 (25%) and eccrine carcinoma in 17 (15%) patients. Porocarcinoma was significantly associated with organ-transplant and hematological cancer (p=0.03), and other skin cancers (p < 0.01). Disease recurred following surgical resection in 24 patients (21%) and median RFS was 68 months (95% CI 45.7-90.3). Head and neck tumors (p=0.05), larger size (p=0.04) and higher stage (p<0.01) were associated with increased risk of recurrence. Among 49 patients with stage I, 34 underwent completion of surgical resection after excisional biopsy, and it was associated with a longer OS (HR: 0.26 95% CI 0.08-0.78 p=0.01). Only 13 (11%) patients had stage IV disease at diagnosis, and the most common site of metastasis was the lung. Median OS for stage IV was 37 months (95%CI 20.6-53.3) (median follow-up 17 months). Median follow-up was 24 months for patients with localized disease and median OS was not reached (95% CI NE). Table: 877P
| MCATs - n (%) | |
| Age (years) – median (range) | 73 (27-95) |
| Sex male | 75 (66) |
| Histology groups Sweat gland Sebaceous Follicular | 83 (73) 28 (25) 3 (2) |
| Primary site Head and neck Trunk Extremities | 73 (64) 15 (13.2) 26 (22.8) |
| Comorbidities Organ transplant Hematological cancer Other skin cancer | 25 (22) 8 (7) 54 (47) |
Conclusions
Patients with MCATs have a good prognosis when detected early and are adequately resected. Careful dermatological surveillance in immunosuppressed patients is warranted.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
E.C. Koch: Financial Interests, Personal, Invited Speaker: Novartis, MSD; Financial Interests, Personal, Advisory Board: Novartis, MSD; Financial Interests, Institutional, Other, Funding: Alamos Gold Inc.; Financial Interests, Institutional, Research Grant: Novartis. M. Vilbert: Financial Interests, Institutional, Funding: Alamos Gold Inc. T. Pimentel Muniz: Financial Interests, Institutional, Research Grant: Novartis; Financial Interests, Institutional, Funding: Alamos Gold Inc. S. Saibil: Financial Interests, Personal, Advisory Board: Novartis. A. Spreafico: Financial Interests, Personal, Advisory Board: Merck, Bristol Myers Squibb, Oncorus, Janssen, Medison & Immunocore; Financial Interests, Institutional, Research Grant: Novartis, Bristol Myers Squibb, Symphogen AstraZeneca/MedImmune, Merck, Bayer, Surface Oncology, Northern Biologics, Janssen Oncology/Johnson & Johnson, Roche, Regeneron, Alkermes, Array Biopharma/Pfizer, GSK, Oncorus, Treadwell, Amgen. M.O. Butler: Financial Interests, Personal, Advisory Board: Bristol Myers Squibb, EMD Serono, GlaxoSmithKline, Immunocore, Merck, Novartis, Pfizer, Sanofi; Financial Interests, Institutional, Research Grant: Merck; Financial Interests, Personal, Other, Safety Review Board: Adaptimmune, GlaxoSmithKline. All other authors have declared no conflicts of interest.