Tumor volume as a prognostic factor in resectable malignant melanoma

Background: Vertical tumor thickness according to Breslow and histological ulceration are still the most powerful predictors for the clinical outcome of resectable cutaneous malignant melanoma (MM) without lymph node infiltration. It has been proposed that tumor volume in MM may also be of prognostic relevance. Methods: We retrospectively analyzed the prognostic impact of tumor volume and other established risk factors in 122 MM patients with a median follow-up period of 39.7 months. Results: We found the logarithmic tumor volume to be a better prognostic factor compared to Breslow tumor thickness in multivariate analysis. MM with a tumor volume below a threshold of 140 mm³ had a significantly higher relapse-free survival after 5 years of 98% compared to 47% in larger MMs (p < 0.0001). Conclusion: In some melanomas with a low tumor thickness, a higher tumor volume appeared to be linked to a higher risk of disease recurrence. Inclusion of tumor volume into the risk assessment of resectable MM may be of benefit in the future.