Basal Cell Carcinoma in Xeroderma Pigmentosa: Reduced CD1a Expression as a Sensitive Predictor of Recurrence

Area of Science:

• Dermatology
• Immunology
• Oncology

Background:

• Xeroderma pigmentosa (XP) is a rare genetic disorder causing defective DNA repair after UV damage, leading to a high incidence of cutaneous malignancies like basal cell carcinoma (BCC).
• Basal cell carcinoma (BCC) development is often associated with impaired local immune responses, particularly involving Langerhans cells (LCs).

Purpose of the Study:

• To investigate the role of Langerhans cells (LCs) in basal cell carcinoma (BCC) specimens from Xeroderma pigmentosa (XP) patients and non-XP controls.
• To determine if the count and distribution of LCs correlate with BCC recurrence in both XP and non-XP patient groups.

Main Methods:

• A retrospective analysis of 48 primary facial BCC specimens (18 XP, 30 non-XP controls) was conducted.
• Langerhans cells (LCs) were quantified immunohistochemically using the CD1a marker in intratumoral, peritumoral, and perilesional epidermal areas.
• Specimens were categorized into recurrent and non-recurrent groups based on 5-year follow-up data.

Main Results:

• XP patients exhibited significantly lower LCs counts in all assessed areas compared to non-XP controls (P < 0.001).
• Recurrent BCC specimens showed significantly lower LCs counts (intratumoral, peritumoral, perilesional) than non-recurrent ones in both XP and control groups (P ≤ 0.02).
• LCs counts correlated positively with BCC duration and relapse interval in recurrent cases, and varied by tumor location in non-XP controls.

Conclusions:

• Reduced Langerhans cell (LC) counts in primary basal cell carcinoma (BCC) specimens are associated with increased tumor recurrence risk in both Xeroderma pigmentosa (XP) patients and the general population.
• LCs may serve as a predictive biomarker for BCC recurrence, potentially guiding stricter therapeutic and preventive strategies.
• This study highlights a novel avenue for immunosurveillance against skin cancer relapse, particularly in XP patients, warranting further investigation.