Patients with both melanoma of the skin and positive lymph nodes may suffer regional relapse after lymphadenectomy, according to a report in the Annals of Surgical Oncology (8:109-115, 2001). The report cites a study by John Gibbs, md, and colleagues in the department of surgery at Roswell Park Cancer Institute (RPCI) that determined the factors that put patients at risk for regional recurrence. The results have led RPCI to recommend lymph node mapping and sentinel lymph node biopsy to identify patients with microscopic disease. These results may have implications for adjuvant treatment decisions, choice of clinical trials, and progressive approaches that affect the results of sentinel lymph node biopsy.
The study evaluated the risk factors for locoregional recurrence and clinical outcome in 338 cutaneous malignant melanoma patients treated at RPCI between January 1970 and December 1996. The patients, who had microscopically and macroscopically involved lymph nodes, were treated with either elective or therapeutic lymph node dissection (LND) and without adjuvant radiotherapy.
Traditionally, there has been no controversy about the need for therapeutic LND of the regional nodal basin draining the site of the primary tumor in patients with obviously involved lymph nodes. The controversy was whether there was any survival advantage in performing elective LND in patients with no obvious disease," according to Dr. Gibbs. "The advent of lymphatic mapping and sentinel lymph node biopsy has changed that."
Risk Factors Identified
In the RPCI study, regional recurrence occurred in 14% of the patients treated with elective LND and 28% of those treated with therapeutic LND. Advanced age, head and neck primary, depth of primary lesion, number of involved lymph nodes, and the higher incidence of extracapsular extension were identified as risk factors associated with nodal recurrence in the study population. The 10-year disease-free survival was 51% for the elective LND group, compared to 30% for the therapeutic LND group. Also, regional failure was predictive of distant metastasis in 87% of the patients, compared to 54% of patients without nodal recurrence. The study found that few patients presented with isolated nodal recurrence, but that most of those who did could be treated successfully with a second procedure.
"The results of this study are consistent with literature describing relapse rates after therapeutic, elective, and the current selective lymph node dissection performed after positive sentinel lymph node biopsy as well as prognostic factors associated with the development of nodal recurrence," Dr. Gibbs noted.
The authors point out that despite reports of the significant incidence of nodal failure following regional lymphadenectomy for melanoma (up to 52%), few studies have attempted to address the means of improving regional control. They conclude that preventing initial failure by using the risk factors identified to stratify patients by low and high probability for recurrence should be the priority.
"Nodal recurrence frequently heralds systemic disease and a dismal prognosis," said Dr. Gibbs. "Thus, every attempt should be made to control stage III disease when it is microscopic, through lymphatic mapping and SLNB for high-risk patients, and adjuvant radiation therapy for patients with four or more positive lymph nodes or extracapsular extension."