Background: The predictive value of regression in melanoma is debated.
Aim of the study: A retrospective single-centre study to evaluate the correlation between regression in primary skin tumor and the presence of micrometastases in sentinel lymph nodes.
Patients and methods: Histological signs of regression in 84 melanomas (>1 mm) with corresponding sentinel lymph nodes were studied by two independent pathologists.
Results: Regression was seen in 40 skin melanoma tumors while micrometastasis was seen in 24. Of the tumors with micrometastasis, only 10 were regressive (RR: 0.47, p=0.49). Breslow value>2 mm and male sex were predictive for node micrometastasis (RR: 4.6, p=0.03 and RR: 7.6, p=0.006, respectively). On multivariate analysis, these two factors were independent.
Comments: These data suggest that regression in primary cutaneous melanoma is not predictive for lymph node metastasis.