Sentinel lymph node biopsy for melanoma: a plea to let the data speak

The Evolution of the Sentinel Node Biopsy in Melanoma

The growing repertoire of approved immune-checkpoint inhibitors and targeted therapy has revolutionized the adjuvant treatment of melanoma. While the treatment of primary cutaneous melanoma remains wide local excision (WLE), the management of regional lymph nodes continues to evolve in light of practice-changing clinical trials and dramatically improved adjuvant therapy. With large multicenter studies reporting no benefit in overall survival for completion lymph node dissection (CLND) after a positive sentinel node biopsy (SLNB), controversy remains regarding patient selection and clinical decision-making. This review explores the evolution of the SLNB in cutaneous melanoma in the context of a rapidly changing adjuvant treatment landscape, summarizing the key clinical trials which shaped current practice guidelines.

Malignant melanoma in the pediatric population

Controversial pigmented lesions in children are a problem for pathologist, clinicians and families that are confronted with this dilemma. Some skin lesions in this population defy diagnosis with pathologists split between a benign diagnosis and a cancer diagnosis. Three cases of controversial pigmented lesions in the pediatric population are presented. Three patients underwent radical resection of the controversial pigmented lesion, intra-operative lymphatic mapping and sentinel lymph node (SLN) biopsy. Due to the low morbidity of the SLN procedure a case is made to perform lymphatic mapping in this clinical scenario. If the SLNs are negative, not much is lost except for the scar and this becomes another line of evidence that perhaps the original lesion was benign. If the SLN shows metastatic cells, then the original skin lesion must be malignant and the patient is offered stage III recommendations that would include complete node dissections and adjuvant Interferon therapy. This strategy provides for adequate treatment of the worse-case scenario, that the skin lesion is malignant. The cost to the patient is a low morbidity procedure, the SLN biopsy.

Prospective study of patterns of surgical management in adults with primary cutaneous melanoma at high risk of spread, in Queensland, Australia

BACKGROUND

Knowledge of variation in diagnosis and surgery in high-risk primary melanoma patients is limited. We assessed frequency and determinants of diagnostic procedures, wide local excision (WLE) and sentinel lymph node biopsy (SLNB).

METHODS

People in Queensland newly diagnosed with melanoma, clinical stage 1b or 2, were recruited prospectively. Patient information was collected from questionnaires and pathology records. Differences in surgical procedures in relation to host and tumor characteristics were assessed.

RESULTS

In 787 participants, primary melanoma was diagnosed by surgical excision (74%), shave (14%), punch (12%) or incisional (1%) biopsy. General practitioners (GPs) diagnosed 80%. Diagnostic procedure differed by remoteness of residence, health sector, treating doctor's specialty and melanoma site and thickness. 766 patients had WLE, 86% by surgeons. Of 134 residual melanomas, 13 (10%) were ≤ 1 mm at diagnosis but > 1 mm at WLE, mostly after shave biopsy. SLNB was performed in 261 (33%) patients. SLNB was more common in those under 50, in remoter locations or treated by GP initially, and less common with head and neck melanoma.

CONCLUSION

Diagnostic and surgical procedures for primary melanoma vary substantially and partial biopsy can influence initial tumor microstaging. Patient, tumor and doctor characteristics influence SLNB practice.