Podoplanin expression in cancer-associated fibroblasts predicts aggressive behavior in melanoma

Recent studies have showed podoplanin expression in several tumors, which has been associated with lymph node metastasis and poor prognosis. Podoplanin expression in cancer-associated fibroblasts also correlates with tumor progression. However, the association of podoplanin expression with melanomas remains unclear.

To clarify the prognostic significance of podoplanin in melanoma, podoplanin expression in tumor cells and cancer-associated fibroblasts was examined by immunohistochemistry in tissue samples collected from 55 melanoma patients.

Podoplanin expression in tumor cells was identified in 38 patients (69.1%) but did not show correlation with characteristics of tumor progression such as tumor thickness (p = 0.52) and sentinel lymph node (SLN) metastasis (p = 0.79). Podoplanin expression in cancer-associated fibroblasts was observed in 25 patients (45.5%), 11 of whom (44.0%) had SLN metastasis. In contrast, only 4 of 30 patients (13.3%) with podoplanin-negative cancer-associated fibroblasts exhibited SLN metastasis. Podoplanin-positive cancer-associated fibroblasts were associated with increased tumor thickness and SLN metastasis. Furthermore, patients with podoplanin-positive cancer-associated fibroblasts had poorer survival than those with podoplanin-negative cancer-associated fibroblasts (p = 0.0148).

The presence of podoplanin expression in cancer-associated fibroblasts correlates with aggressive behavior in melanoma and might therefore serve as a useful prognostic factor for patients with melanoma.