Prognostic value of galectin-3 in primary cutaneous melanoma

Galectin-3, one of the β-galactoside-binding lectins, has been suggested as a marker of disease progression in melanoma patients because of its overexpression observed in recent studies. However, prognostic value of galectin-3 in primary cutaneous melanoma (PCM) has not been clearly defined.

The aim of the study was to analyse whether the intensity of galectin-3 expression can predict survival in patients with PMC.

Galectin-3 expression was evaluated using immunohistochemistry in 104 PCM samples, including 71 (68.2%) superficial spreading (SSM) and 33 (31.8%) nodular melanomas (NM).

Significant difference of galectin-3 expression between SSM and NM was determined (P < 0.001). Increased galectin-3 expression was positively correlated with tumour thickness (P < 0.001), Clark (P < 0.001) and Breslow (P < 0.001) stage, mitotic rate (P < 0.001), presence of tumour ulceration (P < 0.001), lymphatic invasion (P = 0.018), positive sentinel lymph node (P < 0.022) and distant metastases (P < 0.001). Kaplan-Meier analysis showed an association between increased galectin-3 expression and reduced recurrence-free survival (RFS) (P = 0.001) and reduced disease-specific survival (DSS) (P = 0.015). In Cox proportional hazards regression analysis, significant predictors of reduced RFS were positive sentinel lymph node (P = 0.025) and lymphovascular invasion (P = 0.021), whereas predictors of DSS were tumour thickness (P = 0.012), lymphovascular invasion (P = 0.047), Clark stage (P = 0.029) and location of tumour on upper extremities (P = 0.024).

Our results support the potential role of galectin-3 in PCM development, progression and metastasis. Moreover, galectin-3 could serve as an additional prognostic marker that might help in further stratifying the risk of disease progression and metastasis in patients with PMC.