[495] Immunopathological Features of Cutaneous Squamous Cell Carcinomas in Immunocompromised Patients

CM Valentino, R Krouse, D Bradely-Dunlop, R Nagle, E Akporiaye, A Prasad. University of Arizona, Tucson, AZ; United States Department of Veteran Affairs, Tucson, AZ

Background: An immunocompromised (IC) state may contribute to the increased development of cutaneous squamous cell carcinoma (CSCC). This study is an initial evaluation of the immunologic & histopathological differences within CSCC arising in IC and non-IC patients.
Design: Twenty cases of CSCC were included in this study (10 IC and 10 non-IC). An IC state was due to immunosuppressive therapy or underlying disease. Histological features i.e. size and depth of tumor, and degree of differentiation were studied. Immunohistochemical analysis was performed using antibodies against CD4, CD8, CD1a, HLA-G, CD83, CD207, and Granzyme B. Paired student t-test statistical analysis was used to evaluate data.
Results: There was no difference in age and site between IC and non-IC patients. CSCC in IC patients had an average size of 1.9cm. vs 1.5cm. in non-IC patients. Tumors in the IC group invaded deeper (6 mm. vs 3mm.). 7/10 CSCC in the IC group were moderately to poorly differentiated, 3 were well differentiated. 6 of 10 tumors in the non-IC group were well differentiated, and the remaining four were moderately differentiated. There was a trend towards increased numbers of CD4 (p=0.056) and CD8 (p=0.0489) T cells in tumor tissue compared to normal tissue in both groups. There was an increased ratio of CD4:CD8 T cells (p=0.021) in the adjacent normal skin in non IC patients however there was an almost 5 fold decrease in CD4: CD8 ratio within the tumor of non IC group compared to the IC group reflecting an increased number of CD8 positive T cells in the tumor of both groups. Though there was a modest increase in CD1a positive dendritic cells in tumor and adjacent normal tissue of non-IC patients, there was a decreased number of CD207 positive Langerhans cells in the tumors of both groups. CD83 staining was minimal and correlated with the absence of Granzyme B staining in the tumor and normal skin of both groups.
Conclusions: CSCC in Immunocompromised individuals tend to be larger and invade to a greater depth. These tumors are more non well differentiated compared to CSCC in non-IC patients. These data suggest a lack of effector anti-tumor function at the tumor site in both groups that may contribute to tumor progression. Unlike previous reports, no staining was observed in SCC tumor tissue from both groups for non-classical HLA-G, which has been associated with tolerance induction reflecting a negative immune regulatory role in CSCC.
Category: Dermatopathology

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 59, Wednesday Morning