Histologic Status of Squamous Cell Carcinoma In Situ After Diagnostic Biopsy in Immunocompetent and Immunosuppressed Patients.

BACKGROUND

The histologic status of squamous cell carcinoma in situ (SCC-IS) after diagnostic biopsy has not been well described or compared between immunocompetent and immunosuppressed patients. Expression of immunohistochemical (IHC) markers of aggressive SCC has not been compared between SCC-IS that clears or becomes invasive after biopsy.

OBJECTIVE

To determine the histologic status of SCC-IS after diagnostic biopsy in these populations.

METHODS

Retrospective analysis of 129 patients with SCC-IS treated with excision and 55 patients treated with Mohs surgery. Histologic features of SCC in excised tissue after biopsy were recorded. Known SCC markers were evaluated using IHC.

RESULTS

Invasive SCC was found in 3% to 16% of residual SCC-IS depending on surgical treatment modality. The history of skin cancer increased the odds of having invasive SCC in SCC-IS excisions (odds ratio 7.1, p < .05). Forty-seven percent of SCC-IS in immunosuppressed patients cleared after diagnostic biopsy compared with 70% in immunocompetent patients (p < .05). Inflammatory infiltrate and molecular markers of aggressive SCCs (Ki-67, matrix metalloproteinase [MMP]-9, MMP-7, transforming growth factor-beta (TGFβ)-RI, TGFβ-RII, and Sox-2) were not predictive of residual or invasive SCC at the time of treatment.

CONCLUSION

Up to 16% of SCC-IS showed invasive SCC at the time of surgical treatment. Immunosuppressed patients are more likely to have residual disease after biopsy. IHC markers of invasive SCC may not predict invasion.