The prognostic significance of sentinel node tumour burden in melanoma patients: an international, multicenter study of 1539 sentinel node-positive melanoma patients

Melanoma characteristics in Brazil: demographics, treatment, and survival analysis

Background

The incidence of melanoma, one of the most aggressive of the skin cancers, has been increasing worldwide in the last few decades. Data from Latin America and Brazil remain scarce. We aimed to describe the demographic, clinical, and histopathological data; therapy characteristics; and survival rates of the Brazilian melanoma patient population.

Results

We collected and analysed retrospective data from 15 years at a tertiary cancer centre. We describe patient characteristics and treatment. We calculated survival, and identified the main prognostic factors through univariate and multivariate analysis. We analysed a total of 1073 patients, with a mean age of 56.7 years. Men and women experienced similar prevalence, and 91.2% of patients had white skin. The most prevalent subtype was superficial spreading, and the most prevalent anatomic location was the trunk (32.2%), followed by the lower extremities (28%). Of all cases, 567 (52.9%) were assigned to clinical stages I and II, while 382 (32.6%) were stages III and IV. Surgery was the main treatment. Sentinel node biopsy was performed in 373 patients, with 23.8% positivity. Overall actuarial 5-year survival was 67.6%. Multivariate analysis showed that gender, serum lactate dehydrogenase (LDH) levels at diagnosis; anatomic location, TNM stage, and local recurrence were significant prognostic factors.

Conclusions

Overall survival was lower than worldwide rates. The main factors influencing survival were similar to those in other populations. Local recurrence was independently associated with lower survival rates. The high prevalence of advanced cases reinforces the importance of strategies to diagnose melanomas in the early stages. There is a need for future multi-institutional prospective studies to attain a better understanding of possible socioeconomic and other influences on survival among melanoma populations in Brazil and Latin America.

[Sentinel node in melanoma and breast cancer. Current considerations]

The main objectives of sentinel node (SN) biopsy is to avoid unnecessary lymphadenectomies and to identify the 20-25% of patients with occult regional metastatic involvement. This technique reduces the associated morbidity from lymphadenectomy and increases the occult lymphatic metastases identification rate by offering the pathologist the or those lymph nodes with the highest probability of containing metastatic cells. Pre-surgical lymphoscintigraphy is considered a "road map" to guide the surgeon towards the sentinel nodes and to localize unpredictable lymphatic drainage patterns. The SPECT/CT advantages include a better SN detection rate than planar images, the ability to detect SNs in difficult to interpret studies, better SN depiction, especially in sites closer to the injection site and better anatomic localization. These advantages may result in a change in the patient's clinical management both in melanoma and breast cancer. The correct SN evaluation by pathology implies a tumoral load stratification and further prognostic implication. The use of intraoperative imaging devices allows the surgeon a better surgical approach and precise SN localization. Several studies reports the added value of such devices for more sentinel nodes excision and a complete monitoring of the whole procedure. New techniques, by using fluorescent or hybrid tracers, are currently being developed.

Contemporary controversies and perspectives in the staging and treatment of patients with lymph node metastasis from melanoma, especially with regards positive sentinel lymph node biopsy

The management of melanoma lymph node metastasis particularly when detected by sentinel lymph node biopsy (SLNB) is still controversial. Results of the only randomized trial conducted to assess the therapeutic value of SLNB, the Multicenter Selective Lymphadenectomy Trial (MSLT-1), have not conclusively proven the effectiveness of this procedure but are interpreted by the authors and guidelines as indicating SLNB is standard of care. After surgery, interferon alpha had a small survival benefit and radiotherapy has limited effectiveness for patient at high-risk of regional recurrence. New drugs, including immune modulating agents and targeted therapies, already shown to be effective in patients with distant metastasis, are being evaluated in the adjuvant setting. In this regard, ensuring high quality of surgery through the identification of reliable quality assurance indicators and improving the homogeneity of prognostic stratification of patients entered onto clinical trials is paramount. Here, we review the controversial issues regarding the staging and treatment of melanoma patients with lymph node metastasis, present a summary of important and potentially practice changing ongoing research and provide a commentary on what it all means at this point in time.