Prognostic factors for in-transit metastasis in patients with malignant melanoma

Abstract

Background and aims. Malignant melanoma represents an aggressive and unpredictable malignancy, with high locoregional recurrence rates, regardless of tumor stage and therapeutic management. This study aims to identify the main histopathological prognostic factors involved in the development of in-transit metastasis in patients with malignant melanoma.
 Methods. The study includes only patients that were diagnosed with malignant melanoma and with histologically confirmed in-transit metastasis who were treated in a comprehensive cancer center between 2010-2021. Histopathological parameters were investigated, univariate and multivariate analysis was performed.
 Results. A total of 26 patients were included in the analysis. On univariate and multivariate analysis, only primary cutaneous melanomas located on the thorax correlated with the risk of developing in-transit metastasis, whereas clinicopathological factors such as an increased Breslow thickness and Clark level, the presence of ulceration, positive lymph nodes, a non-brisk TIL density, a high mitotic rate, a nodular subtype, and age>50 years may represent risk factors, even though we could not find any correlations.
 Conclusions. Primary cutaneous melanomas that arise on the thorax present a high risk for the occurrence of locoregional disease, whereas other clinicopathological characteristics could not be used to predict local recurrence. However, prospective and more extensive cohort studies are needed in order to validate these important prognostic factors.

The role of micrometastasis in high‐risk skin cancers

“…Significantly, the clinical appearance of ITM is found to be present both before and after SLN positivity. This finding supports the co‐incident presence of micrometastasis within the drainage basin, including after the treatment of nodal disease 68,69,79 …”

“…This finding supports the coincident presence of micrometastasis within the drainage basin, including after the treatment of nodal disease. 68,69,79…”

“…For skin, these include all intradermal or subdermal metastasis between the primary scar and the tumour‐draining nodal basin 26,61–63 . Macrometastatic ITM present as papulo‐nodules and are described for SCC, 40,62,64 MCC 26,27 and melanoma 58,61,65–68 . As external assay techniques improve in sensitivity, it is expected that smaller mass cancer cell clusters will be identified in lymphatic channels 58 .…”

“…Currently, the two most sensitive assays available are high‐frequency ultrasound sonography and advanced PET techniques, which can detect micrometastases as small as 3–5 mm in diameter 58,69 . Melanoma ITM are principally located within lymphatic vessels in the lower dermis to upper subcutis as semi‐contiguous chains, with deeper penetration occurring once the nodal basin is reached 3,11,50,58,65,68,70 . These new techniques are mostly employed for cancer re‐staging and have been reported to change treatment in up to 75% of cases 58 …”

Metastatic malignant melanoma mimicking urinary bladder mass: A rare presentation

“…Malignant melanoma represents a highly aggressive tumor with an incidence that continued to rise in the past 30 years. It is the deadliest skin cancer, accounting for up to 60% of skin cancer-related deaths, primarily due to rapid proliferation and metastasis [10].…”