Risk Factors for Relapse of Cutaneous Melanoma

Patients with both melanoma of the skin and positivelymph nodes may suffer regional relapse after lymphadenectomy, according to a report in the Annals of Surgical Oncology(8[2]:109-115, 2001). The report cites a study by John Gibbs, md, and colleaguesin the department of surgery at Roswell Park Cancer Institute (RPCI) thatdetermined the factors that put patients at risk for regional recurrence. Theresults have led RPCI to recommend lymph node mapping and sentinel lymph nodebiopsy to identify patients with microscopic disease. These results may haveimplications for adjuvant treatment decisions, choice of clinical trials, andprogressive approaches that affect the results of sentinel lymph node biopsy.

The study evaluated the risk factors for locoregional recurrenceand clinical outcome in 338 cutaneous malignant melanoma patients treated atRPCI between January 1970 and December 1996. The patients, who hadmicroscopically and macroscopically involved lymph nodes, were treated witheither elective or therapeutic lymph node dissection (LND) and without adjuvantradiotherapy.

Traditionally, there has been no controversy about the need fortherapeutic LND of the regional nodal basin draining the site of the primarytumor in patients with obviously involved lymph nodes. The controversy waswhether there was any survival advantage in performing elective LND in patientswith no obvious disease," according to Dr. Gibbs. "The advent oflymphatic mapping and sentinel lymph node biopsy has changed that."

Risk Factors Identified

In the RPCI study, regional recurrence occurred in 14% of thepatients treated with elective LND and 28% of those treated with therapeuticLND. Advanced age, head and neck primary, depth of primary lesion, number ofinvolved lymph nodes, and the higher incidence of extracapsular extension wereidentified as risk factors associated with nodal recurrence in the studypopulation. The 10-year disease-free survival was 51% for the elective LNDgroup, compared to 30% for the therapeutic LND group. Also, regional failure waspredictive of distant metastasis in 87% of the patients, compared to 54% ofpatients without nodal recurrence. The study found that few patients presentedwith isolated nodal recurrence, but that most of those who did could be treatedsuccessfully with a second procedure.

"The results of this study are consistent with literaturedescribing relapse rates after therapeutic, elective, and the current selectivelymph node dissection performed after positive sentinel lymph node biopsy aswell as prognostic factors associated with the development of nodalrecurrence," Dr. Gibbs noted.

Stratifying Patients

The authors point out that despite reports of the significantincidence of nodal failure following regional lymphadenectomy for melanoma (upto 52%), few studies have attempted to address the means of improving regionalcontrol. They conclude that preventing initial failure by using the risk factorsidentified to stratify patients by low and high probability for recurrenceshould be the priority.

"Nodal recurrence frequently heralds systemic disease and adismal prognosis," said Dr. Gibbs. "Thus, every attempt should be madeto control stage III disease when it is microscopic, through lymphatic mappingand SLNB for high-risk patients, and adjuvant radiation therapy for patientswith four or more positive lymph nodes or extracapsular extension."