Angiopoietin-2 is expressed in oral Kaposi's sarcoma

Background: Kaposi's sarcoma (KS) persists today as a highly prevalent vascular cancer, often found in HIV patients. Studies have shown that angiopoietin 2 (Ang2), a pro-angiogenic protein, is involved in the pathogenesis of this tumor. However, expression of this protein has not been investigated in oral KS lesions. Thus, we aimed to investigate the expression of Ang2 in samples of oral KS.

Methods: Immunohistochemistry was used to evaluate Ang2 expression in 14 oral KS cases, with degrees of expression being analyzed in a semi-quantitative manner. In addition, clinical information such as age, gender, race, tumor location, size, color, and appearance, as well as HIV status, was collected and included in the analysis.

Results: All patients were white males, mostly HIV-positive, with a mean age of 40 years. Clinically, the lesions were dark red/blue/purple masses, ranging from 1 to 2.5 cm in diameter, found in various locations such as the tongue, palate, and gingiva. Expression of Ang2 was noted in 72% (10/14) of the samples. Of these, 10% showed weak expression, 60% moderate, and 30% strong expression.

Conclusions: Our results indicate that Ang2 is expressed in oral KS and, consistent with results from previous studies, show that Ang2 may contribute to the pathogenesis of this lesion.