Sentinel lymph node biopsy in patients with T1a cutaneous malignant melanoma: A multicenter cohort study

BAUSSS biomarker improves melanoma survival risk assessment

BACKGROUND

The American Joint Committee on Cancer (AJCC) method of staging melanoma is dated and inaccurate. It ignores important prognostic melanoma features, especially the patient's age. BAUSSS is more accurate in determining survival risk for primary cutaneous melanoma patients who have no clinical or imaging evidence of nodal or distant metastases. BAUSSS is an algorithm incorporating analysis of Breslow thickness, Age, Ulceration, Subtype of melanoma, Sex and Site. These are the six features from the patient history along with the details from the melanoma pathology report that are most predictive of mortality outcome.

OBJECTIVE

To develop a single-page document that allows the clinician to determine BAUSSS biomarker-predicted prognosis in consultation with the patient.

METHOD

From various data sources, we developed an algorithm to predict melanoma mortality using the BAUSSS biomarker system. The single-page algorithm was made available to download at https://globalmelanoma.net/bausss-survival-chart, thus being readily available without charge to all clinicians and their patients.

RESULTS

BAUSSS method of determining melanoma prognosis is more accurate and less costly than the AJCC staging system. The only surgery the patient requires is wide local excision of the primary tumour. This method of ascertaining melanoma risk does not require added surgery, costs, hospitalization, tests and anaesthesia, such as would be required if sentinel lymph node biopsy was undertaken. BAUSSS can be a useful tool in determining which primary melanoma patients are at sufficiently high risk to be considered for adjuvant drug therapy.

CONCLUSIONS

We encourage clinicians to download and print in colour this single-page BAUSSS mortality prediction tool, laminate it, and use it face to face with the patient in consultations. Not only will the patient be able to recognize his/her long-term prognosis but will also be able to see how their tumour severity compares with others.

Predictors of SLNB in Thin Melanoma: Understanding the Impact of the American Joint Committee on Cancer 8th Edition Staging System

BACKGROUND

The definition of T1b cutaneous melanoma was changed in the 8th edition of the American Joint Committee on Cancer (AJCC) staging system based on survival differences but not risk of sentinel lymph node (SLN) metastases. We sought to evaluate changes in SLNB use and rates of positive SLNB in response to updated staging criteria, and to evaluate the incidence of high-risk features in T1a melanoma in whom SLNB is now recommended.

STUDY DESIGN

The 2021 National Cancer Database Melanoma Participant User File was used to obtain SLNB use and positivity rates in T1 (thin) melanoma (thickness 1.0 mm or less) from 2012 to 2021. Rates were compared between AJCC 7th (2012 to 2017) and 8th editions (2018 to 2021). Factors associated with SLNB use in nonulcerated T1 melanoma were evaluated. The presence of high-risk features in T1a melanoma was identified and SLN positivity rates were reviewed.

RESULTS

A total of 136,966 cases were included with 76,485 (55.8%) cases diagnosed under the AJCC 7th edition era (2021 to 2017). The overall proportion of patients with thin melanoma undergoing SLNB was relatively stable over the time periods, roughly 30%. In the AJCC 8th edition era, the overall SLNB positivity rate slightly increased from 4.5% to 6.6% (p < 0.001). There was increased SLNB use in melanoma with a thickness of 0.8 to 1.0 mm (T1b: odds ratio 2.53 [95% CI 2.31 to 2.78]) and decreased use when the thickness was less than 0.8 mm (T1a: odds ratio 0.80 [0.76 to 0.85]). The rate of SLNB positivity increased in both thickness groups over time.

CONCLUSIONS

After implementation of the AJCC 8th edition staging criteria, surgeons have become more selective in SLNB use with a resulting increase in SLNB positivity rate. Fewer SLNBs in T1a and more SLNBs in nonulcerated T1b are being performed.

An Evaluation of Sentinel Lymph Node Biopsy Guideline Adherence in Melanoma

BACKGROUND

Regional lymph nodes are a common first site of metastasis in patients diagnosed with invasive melanoma. Knowledge of sentinel lymph node status provides strong prognostic information in melanoma and is important for staging and treatment decisions. The National Comprehensive Cancer Network® (NCCN) recommends performance of sentinel lymph node biopsy (SLNB) for melanoma patients with a T category of ≥T2a. This study aims to assess our academic institution's guideline adherence to improve quality of care.

METHODS

Retrospective review of medical records from 2017 to 2023 identified 628 patients referred to our institution for invasive melanoma treatment. Adherence to guidelines was assessed using Chi-square analyses and Fisher's exact tests.

RESULTS

In total, 8.2% of cases did not follow the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for SLNB. When justification provided within the medical record was considered adherent to guidelines, our rate of discordance was 1.6%. Head and neck melanomas were more likely to have guideline-discordant SLNB management, regardless of whether or not a justification was provided.

CONCLUSION

Greater than 98% of melanoma cases at our institution aligned with the SLNB NCCN Guidelines®. We outlined the complex justifications physicians and patients may use to pursue care that is nonadherent to guidelines. Employment of SLNB may be limited by medical comorbidities, surgical risks, and when the management would not change based on the result. Our study provides a blueprint for institutional assessment of guideline adherence and highlights the importance of documentation and guideline dissemination.

Effect of smoking on melanoma incidence: a systematic review with meta-analysis

BACKGROUND

There is a strong correlation between cigarette smoking and the development of many cancer types. It is therefore paradoxical that multiple reports have suggested a reduced incidence of melanoma in smokers. This study aimed to analyze all existing studies of melanoma incidence in smokers relative to nonsmokers.

METHODS

Searches of MEDLINE and Embase were conducted for studies reporting data on melanoma in smokers and never-smokers. No study design limitations or language restrictions were applied. The outcome examined was the association between smoking status and melanoma. Analyses focused on risk of melanoma in smokers and never-smokers generated from multivariable analyses, and these analyses were pooled using a fixed-effects model. Risk of bias was assessed using the Newcastle-Ottawa tool.

RESULTS

Forty-nine studies that included 59 429 patients with melanoma were identified. Pooled analyses showed statistically significant reduced risks of melanoma in male smokers (risk ratio [RR] = 0.60, 95% confidence interval [CI] = 0.56 to 0.65, P < .001) and female smokers (RR = 0.79, 95% CI = 0.73 to 0.86, P < .001). Male former smokers had a 16% reduction in melanoma risk compared with male never-smokers (RR = 0.84, 95% CI = 0.77 to 0.93, P < .001), but no risk reduction was observed in female former smokers (RR = 1.0, 95% CI = 0.92 to 1.08).

CONCLUSIONS

Current smokers have a statistically significant reduced risk of developing melanoma compared with never-smokers, with a reduction in melanoma risk of 40% in men and 21% in women.

How Many Sentinel Lymph Nodes Should We Excise in Patients With Melanoma?

INTRODUCTION

The management of many patients with early-stage melanoma includes sentinel lymph node (SLN) biopsy for prognostic and treatment planning purposes. While the minimum necessary number of SLNs to examine has been determined for patients with other malignancies, it has not been delineated in melanoma. The current study evaluates risk factors for SLN positivity and the associated number of SLNs that are necessary to examine for appropriate staging.

MATERIALS AND METHODS

The National Cancer Database participant user file from 2018 to 2020 was queried for clinically node-negative patients who underwent SLN biopsy. Descriptive statistics were obtained. Analysis of variance statistical analyses were performed.

RESULTS

Eight thousand forty eight melanoma patients out of 48,748 were identified from 2018 to 2020 that had lymph node positivity on SLN biopsy. The median age of patients was 64. The male-to-female ratio was 1.47. Chi-squared analysis revealed that there was a statistically significant difference in positivity rate between at least two groups (P = 0.006) for primary melanoma site, male sex (P < 0.01), race, age, histologic type, Breslow thickness, and lymphovascular invasion (P < 0.001). SLN positivity rate increased with the number of SLNs examined until plateauing at 4 SLNs. There was no statistical difference between positivity for 3 SLNs and larger numbers of SLNs examined. Propensity matching revealed no statistically significant difference in positive rate when more than 2 SLNs were biopsied.

CONCLUSIONS

SLN positivity is proportionally related to the number of SLNs examined, suggesting that surgeons should attempt to remove a minimum of 2 SLNs for the optimal staging of patients with melanoma.

Impact of an Online Risk Calculator for Sentinel Node Positivity on Management of Patients with T1 and T2 Melanomas

BACKGROUND

Predicting which patients with American Joint Committee on Cancer (AJCC) T1-T2 melanomas will have a positive sentinel lymph node (SLN) is challenging. Melanoma Institute Australia (MIA) developed an internationally validated SLN metastatic risk calculator. This study evaluated the nomogram's impact on T1-T2 melanoma patient management at MIA.

METHODS

SLN biopsy (SLNB) rates were compared for the pre- and post-nomogram periods of 1 July 2018-30 June 2019 and 1 August 2020-31 July 2021, respectively.

RESULTS

Overall, 850 patients were identified (pre-nomogram, 383; post-nomogram, 467). SLNB was performed in 29.0% of patients in the pre-nomogram group and 34.5% in the post-nomogram group (p = 0.091). The overall positivity rate was 16.2% in the pre-nomogram group and 14.9% in the post-nomogram group (p = 0.223). SLNB was performed less frequently in T1a melanoma patients in the pre-nomogram group (1.1%, n = 2/177) than in the post-nomogram group (8.6%, n = 17/198) [p ≤ 0.001]. This increase was particularly for melanomas with a risk score ≥ 5%, with an SLN positivity rate of 11.8% in the post-nomogram group (p = 0.004) compared with zero. For T1b melanomas with a risk score of > 10%, the SLNB rate was 40.0% (8/20) pre-nomogram and 75.0% (12/16) post-nomogram (p = 0.049).

CONCLUSIONS

In this specialized center, the SLN risk calculator appears to influence practice for melanomas previously considered low risk for metastasis, with increased use of SLNB for T1a and higher-risk T1b melanomas. Further evaluation is required across broader practice settings. Melanoma management guidelines could be updated to incorporate the availability of nomograms to better select patients for SLNB than previous criteria.

Validation of the Melanoma Institute of Australia's Sentinel Lymph Node Biopsy Risk Prediction Tool for Cutaneous Melanoma

BACKGROUND

For patients with cutaneous melanoma, sentinel lymph node biopsy (SLNB) is used to stage regional lymph nodes pathologically and inform prognosis, treatment, and surveillance. To reduce unnecessary surgeries, predictive tools aim to identify those at lowest risk for node-positive disease. The Melanoma Institute of Australia (MIA)'s Prediction Tool for Sentinel Node Metastasis Risk estimates risk of a positive SLNB using patient age and primary melanoma Breslow depth, histologic subtype, ulceration, mitotic rate, and lymphovascular invasion.

METHODS

A single-institution validation was performed of the MIA Calculator with 982 cutaneous melanoma patients that included all relevant clinicopathologic factors and SLNB pathology outcomes. The study evaluated discrimination via receiver operating characteristic (ROC) curves, calibration via calibration plots, and clinical utility via decision curve analysis of the MIA model in various subgroups. The data were fit to MIA model parameters via a generalized linear model to assess the odds ratio of parameters in our dataset.

RESULTS

The Calculator demonstrated limited discrimination based on ROC curves (C-statistic, 0.709) and consistently underestimated risk of SLN positivity. It did not provide a net benefit over SLNB performed on all patients or reduce unnecessary procedures in the risk domain of 0% to 16%. Compared with the original development and validation cohorts, the current study cohort had thinner tumors and a larger proportion of acral melanomas.

CONCLUSIONS

The Calculator generally underestimated SLN positivity risk, including assessment in patients who would be counseled to forego SLNB based on a predicted risk lower than 5%. Recognition of the tool's current limitations emphasizes the need to refine it further for use in medical decision-making.

Current surgical management for melanoma

Melanoma is a major malignant cutaneous neoplasm with a high mortality rate. In recent years, the treatment of melanoma has developed dramatically with the invention of new therapeutic agents, including immune checkpoint inhibitors and molecular-targeted agents. These agents are available as adjuvant therapies for postoperative patients with stage IIB, IIC, and III melanomas. Furthermore, neoadjuvant therapy has been studied in several global clinical trials and has demonstrated promising and favorable clinical efficacy, mainly in patients with palpable regional lymph nodes. A recent large phase III clinical trial investigating early lymph node dissection for sentinel lymph node metastases demonstrated no survival benefits. Based on these data, surgery should be reconsidered as an appropriate treatment modality for melanoma. The need for invasive surgical procedures will be reduced with the invention of effective adjuvant and neoadjuvant therapies and novel clinical trial data on regional lymph node dissection. However, surgery still plays an important role in treating early-stage melanoma, accurately determining the disease stage, and effective palliative treatment for advanced melanoma. In this article, we focus on surgery for primary tumors, regional lymph nodes, and metastatic sites in an era of remarkably revolutionary drug treatments for melanoma.

Prognostic and predictive biomarkers in melanoma

Biomarkers help to inform the clinical management of patients with melanoma. For patients with clinically localised primary melanoma, biomarkers can help to predict post-surgical outcome (including via the use of risk prediction tools), better select patients for sentinel lymph node biopsy, and tailor catch-all follow-up protocols to the individual. Systemic drug treatments, including immune checkpoint inhibitor (ICI) therapies and BRAF-targeted therapies, have radically improved the prognosis of metastatic (stage III and IV) cutaneous melanoma patients, and also shown benefit in the earlier setting of stage IIB/C primary melanoma. Unfortunately, a response is far from guaranteed. Here, we review clinically relevant, established, and emerging, prognostic, and predictive pathological biomarkers that refine clinical decision-making in primary and metastatic melanoma patients. Gene expression profile assays and nomograms are emerging tools for prognostication and sentinel lymph node risk prediction in primary melanoma patients. Biomarkers incorporated into clinical practice guidelines include BRAF V600 mutations for the use of targeted therapies in metastatic cutaneous melanoma, and the HLA-A∗02:01 allele for the use of a bispecific fusion protein in metastatic uveal melanoma. Several predictive biomarkers have been proposed for ICI therapies but have not been incorporated into Australian clinical practice guidelines. Further research, validation, and assessment of clinical utility is required before more prognostic and predictive biomarkers are fluidly integrated into routine care.

Is sentinel lymph node biopsy needed for lentigo maligna melanoma?

BACKGROUND AND OBJECTIVES

Sentinel lymph node biopsy (SLNB) is an area of debate in the management of lentigo maligna melanoma (LMM). The utility of SLNB and its prognostic value in LMM have not yet been studied with large databases.

METHODS

We performed a retrospective review of the National Cancer Database (2012-2020) and the Surveillance, Epidemiology, and End Results (2010-2019) database for patients with cutaneous nonmetastatic LMM with Breslow thickness >1.0 mm. Multivariable logistic regression identified factors associated with SLNB performance and sentinel lymph node (SLN) positivity. Univariable and multivariable analyses assessed overall survival (OS) and melanoma-specific survival (MSS) based on SLNB performance and SLN status.

RESULTS

Compared to other melanoma subtypes, LMM had lower rates of SLNB (66.6% vs. 80.0%-84.0%) and SLN positivity (11.3% vs. 18.6%-34.2%). Compared to patients who did not undergo SLNB, SLN status was significantly associated with improved OS in patients with SLN positive (HR = 0.64 [0.55-0.76]) and SLN negative (HR = 0.68 [0.49-0.94]), and worse MSS only in patients with positive SLN (HR = 3.93, p < 0.05).

CONCLUSION

The improved OS associated with SLNB likely implies surgical selection bias. Analysis of MSS confirms appropriate patient selection and suggests important prognostic value associated with SLN status. These results support continued SLNB for LMM patients according to standard guidelines.

Predictors of sentinel lymph node metastasis in very thin invasive melanomas

BACKGROUND

Melanomas < 0.8 mm in Breslow depth have less than a 5% risk for nodal positivity. Nonetheless, nodal positivity is prognostic for this group. Early identification of nodal positivity may improve the outcomes for these patients.

OBJECTIVES

To determine the degree to which ulceration and other high-risk features predict sentinel lymph node (SLN) positivity for very thin melanomas.

METHODS

The National Cancer Database was reviewed from 2012 to 2018 for patients with melanoma with Breslow thickness < 0.8 mm. Data were analysed from 7 July 2022 through to 25 February 2023. Patients were excluded if data regarding their ulceration status or SLN biopsy (SLNB) performance were unknown. We analysed patient, tumour and health system factors for their effect on SLN positivity. Data were analysed using χ2 tests and logistic regressions. Overall survival (OS) was compared by Kaplan-Meier analyses.

RESULTS

Positive nodal metastases were seen in 876 (5.0%) patients who underwent SLNB (17 692). Factors significantly associated with nodal positivity on multivariable analysis include lymphovascular invasion [odds ratio (OR) 4.5, P < 0.001], ulceration (OR 2.6, P < 0.001), mitoses (OR 2.1, P < 0.001) and nodular subtype (OR 2.1, P < 0.001). Five-year OS was 75% and 92% for patients with positive and negative SLN, respectively.

CONCLUSIONS

Nodal positivity has prognostic significance for very thin melanomas. In our cohort, the rate of nodal positivity was 5% overall in these patients who underwent SLNB. Specific tumour factors (e.g. lymphovascular invasion, ulceration, mitoses, nodular subtype) were associated with higher rates of SLN metastases and should be used to guide clinicians in choosing which patients will benefit from SLNB.

Role of Sentinel Lymph Node Biopsy for Skin Cancer Based on Clinical Studies

The sentinel lymph node is the first lymph node from the primary tumor. Sentinel lymph node biopsy (SLNB) is a surgical procedure that can detect occult nodal metastasis with relatively low morbidity. It may also have a therapeutic effect via regional disease control. The Multicenter Selective Lymphadenectomy-I (MSLT-I) trial revealed a prognostic benefit from SLNB in melanoma patients. However, it remains unclear whether there is a prognostic benefit from SLNB in patients with nonmelanoma skin cancer owing to a lack of randomized prospective studies. Nevertheless, SLNB provides important information about nodal status, which is one of the strongest factors to predict prognosis and may guide additional nodal treatment. Currently, SLNB is widely used in the management of not only patients with melanoma but also those with nonmelanoma skin cancer. However, the utilization and outcomes of SLNB differ among skin cancers. In addition, SLNB is not recommended for routine use in all patients with skin cancer. In this review, we provide a summary of the role of SLNB and of the indications for SLNB in each skin cancer based on previously published articles.

The Association of Guideline-Concordant Sentinel Lymph Node Biopsy for Melanoma at Minority-Serving Hospitals

BACKGROUND

Minority-serving hospitals (MSHs) have been associated with lower guideline adherence and worse outcomes for various cancers. However, the relationship among MSH status, concordance with sentinel lymph node biopsy (SLNB) guidelines, and overall survival (OS) for patients with cutaneous melanoma is not well studied.

METHODS

The National Cancer Database was queried for patients diagnosed with T1a*, T2, and T3 melanoma between 2012 and 2017. MSHs were defined as the top decile of institutions ranked by the proportion of minorities treated for melanoma. Based on National Comprehensive Cancer Network guidelines, guideline-concordant care (GCC) was defined as not undergoing SLNB if thickness was < 0.76 mm without ulceration, mitosis ≥ 1/mm², or lymphovascular invasion (T1a*), and performing SLNB for patients with intermediate thickness melanomas between 1.0 and 4.0 mm (T2/T3). Multivariable logistic regressions examined associations with GCC. The Kaplan-Meier method and log-rank tests were used to evaluate OS between MSH and non-MSH facilities.

RESULTS

Overall, 5.9% (N = 2182/36,934) of the overall cohort and 37.8% of minorities (n = 199/527) were managed at MSHs. GCC rates were 89.5% (n = 33,065/36,934) in the overall cohort and 85.4% (n = 450/527) in the minority subgroup. Patients in the overall cohort (odds ratio [OR] 0.85; p = 0.02) and the minority subgroup (OR 0.55; p = 0.02) were less likely to obtain GCC if they received their care at MSHs compared with non-MSHs. Minority patients receiving care at MSHs had a decreased survival compared with those treated at non-MSHs (p = 0.002).

CONCLUSIONS

Adherence to SLNB guidelines for melanoma was lower at MSHs. Continued focus is needed on equity in melanoma care for minority patients in the United States.