Role of elective lymph node dissection in stage I malignant melanoma: evaluation by matched pair analysis.
The role of elective lymph node dissection (ELND) in clinical stage I malignant melanoma continues to be controversial. We present a matched pair analysis of 375 patients treated in the Department of Dermatology in Kassel between 1979 and 1991 by wide local excision (WLE) plus ELND. Multivariate analysis revealed tumor thickness, level of invasion, age, sex, and localization as independent prognostic factors, and 375 patients treated by WLE alone were matched as controls to the patients treated by ELND and WLE. There was no significant benefit from WLE plus ELND compared to WLE alone in the total group as shown by the 5-year survival rates (87.3% versus 86.4%) and 10-year survival rates (80.1% versus 77.82%). Increased survival rates were noted for tumor thicknesses 1.51-4.0 mm for the WLE plus ELND group, as shown by the 10-year survival rates of 73.1% versus 60.3%. However, these data were not significant (p = 0.14). Disease-free survival rates were significantly higher in the group treated by additional ELND for all tumor thicknesses (p < 0.05) and even more in intermediate tumor thicknesses of 1.51-4.0 mm (p < 0.001). A significant benefit of elective lymph node dissection was detected for malignant melanoma of the trunk (all tumor thicknesses), as shown by the 5-year survival rates of 92.0% versus 79.7% and 10-year survival rates of 80.4% versus 45.16% (p < 0.05). Malignant melanoma of the extremities revealed no significant differences in survival rates. We conclude that there is a certain benefit from ELND in clinical stage I malignant melanoma for tumor thicknesses of 1.51-4.00 mm. Especially in malignant melanoma of the trunk, WLE plus ELND was more beneficious than WLE alone.