Histological lymphovascular invasion is associated with nodal involvement, recurrence, and survival in patients with cutaneous malignant melanoma.

BACKGROUND: Invasion of the lymphatic or vascular vessels by the primary tumor is considered a sign of aggressive disease that leads to metastases to the regional lymph nodes and to distant sites. Although lymphovascular invasion (LVI) is one of the major characteristics of a primary melanoma tumor, its prognostic significance remains controversial.

OBJECTIVE: The objective of this study was to determine the clinical significance of LVI in melanoma patients.

METHODS: Outcomes in 705 patients with cutaneous melanoma were investigated retrospectively.

RESULTS: The median age of the patients was 52 years (range: 16-104 years). Of the 705 patients, 624 (88.5%) did not have LVI and 81 (11.5%) patients did. Melanoma patients with LVI more frequently had nodular pathology (P = 0.001), invasion to an advanced Clark level (P = 0.000), greater Breslow thickness (P = 0.000), a high mitotic rate (P = 0.018), ulceration (P = 0.000), neurotropism (P = 0.000), lymph node involvement (P = 0.000), multiple lymph node involvement (P = 0.008), recurrent disease (P = 0.003), and metastatic disease (P = 0.008) than those without LVI. However, LVI was not significantly associated with age, gender, anatomic localization, tumor-infiltrating lymphocytes, vertical growth phase, a pre-existing melanocytic nevus, or type of distant metastasis. Lymphovascular invasion was significantly associated with both recurrence-free (P = 0.000) and overall (P = 0.000) survival. On multivariate analyses, although LVI was not independently associated with RFS (P = 0.134), it retained its significance for overall survival (P = 0.000).

CONCLUSIONS: Lymphovascular invasion has significant prognostic impact on nodal involvement, recurrence, and overall survival in cutaneous melanoma.