Cutaneotropic Polyomavirus Abundance in the Non-lesional Skin of Keratinocyte Carcinoma Patients: A Cross-sectional Study

Background: The relationship between human polyomavirus (HPyV), keratinocyte carcinoma (KC), and T cell immunity is controversial.
Objective: To characterize the abundance of the three most prevalent cutaneotropic HPyVs in basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) patients.
Methods: This cross-sectional study quantitatively examined Merkel cell polyomavirus (MCPyV), HPyV6, and HPyV7 in non-lesional skin tissues from head BCC and cSCC patients. Immunofluorescence characterizations of the skin T cell populations were performed in a subgroup of cases.
Results: Of the 100 non-lesional head skin samples (67 BCC, 33 cSCC), there was a significantly elevated frequency of MCPyV in cSCC patients compared with BCC patients (OR, 6.30; 95%CI, 1.25-31.82; P = 0.026). The viral load of MCPyV was also significantly higher in cSCC cases (P = 0.038). In a subgroup of 13 BCC and 14 cSCC cases, significantly fewer skin-infiltrating CD3+ T (P < 0.001), CD8+CD3+ T (P < 0.001), and CD103+CD8+CD3+ tissue-resident memory T cells (P = 0.003) were identified in cSCC patients.
Limitations: The sample size was limited.
Conclusion: The association between HPyV and KC subtypes might reflect the role of T cells in controlling viral activity and cSCC development and potentially be utilized for cancer risk assessment.