Tumour thickness as a prognostic factor in the evolution of cutaneous malignant melanoma

Abstract

Introduction. Cutaneous malignant melanoma is a biologically heterogeneous neoplasm characterized by marked variability in clinical behaviour and prognosis. Although, multiple histopathologic parameters are incorporated into contemporary risk stratification models, tumour thickness remains one of the most reliable predictors of disease progression and patient outcome. Evaluation of its association with additional clinicopathologic features may further fortify its role as a key determinant in melanoma aggressiveness. The present study assesses the prognostic significance of tumour thickness in superficial spreading melanoma by analysing its correlations with established markers of tumour progression. Materials and Methods. A retrospective analysis was performed on 47 cases of superficial spreading melanoma obtained from the Oncology Institute of Chisinau. All specimens underwent comprehensive histopathologic review to assess tumour thickness, Clark level, ulceration, mitotic activity, microsatellitosis, pigmentation status, and lymph node involvement. Tumour thickness was measured on routine haematoxylin–eosin-stained slides. Statistical analysis of correlations between tumour thickness and clinicopathologic features was performed using Pearson correlation coefficients, with significance defined as p ≤ 0.05. Results. The cohort included 47 patients with a mean age of 65.6 ± 12.15 years; 24 patients (51.1%) were female and 23 (48.9%) were male. Pigmented melanomas accounted for 34 cases (72.3%), while 13 cases (27.7%) were non-pigmented. Tumour thickness demonstrated statistically significant positive correlations with several indicators of tumour aggressiveness, including Clark level (r = 0.60, p = 0.001), ulceration (r = 0.29, p = 0.03), lymphovascular invasion (r = 0.54, p = 0.001), microsatellitosis (r = 0.36, p = 0.01), and advanced tumour stage (r = 0.45, p = 0.001). In contrast, tumour thickness showed a significant inverse correlation with pigmentation status (r = −0.42, p = 0.05), indicating that thicker tumours were more frequently non-pigmented. No additional clinicopathologic parameters reached statistical significance level. Conclusions. Tumour thickness is strongly associated with multiple histopathologic features of aggressive behaviour in superficial spreading melanoma. Its correlation with invasive parameters and advanced tumour stage, along with its inverse association with pigmentation, underscores its central prognostic value. These findings support the continued use of tumour thickness as a key prognostic marker and highlight the importance of integrating morphologic parameters in melanoma risk stratification.