A Novel and Accurate Computer Model of Melanoma Prognosis for Patients Staged by Sentinel Lymph Node Biopsy: Comparison with the American Joint Committee on Cancer Model

Development and validation of a novel model to predict recurrence-free survival and melanoma-specific survival after sentinel lymph node biopsy in patients with melanoma: an international, retrospective, multicentre analysis

BACKGROUND

The introduction of adjuvant systemic treatment for patients with high-risk melanomas necessitates accurate staging of disease. However, inconsistencies in outcomes exist between disease stages as defined by the American Joint Committee on Cancer (8th edition). We aimed to develop a tool to predict patient-specific outcomes in people with melanoma rather than grouping patients according to disease stage.

METHODS

Patients older than 13 years with confirmed primary melanoma who underwent sentinel lymph node biopsy (SLNB) between Oct 29, 1997, and Nov 11, 2013, at four European melanoma centres (based in Berlin, Germany; Amsterdam and Rotterdam, the Netherlands; and Warsaw, Poland) were included in the development cohort. Potential predictors of recurrence-free and melanoma-specific survival assessed were sex, age, presence of ulceration, primary tumour location, histological subtype, Breslow thickness, sentinel node status, number of sentinel nodes removed, maximum diameter of the largest sentinel node metastasis, and Dewar classification. A prognostic model and nomogram were developed to predict 5-year recurrence-free survival on a continuous scale in patients with stage pT1b or higher melanomas. This model was also calibrated to predict melanoma-specific survival. Model performance was assessed by discrimination (area under the time-dependent receiver operating characteristics curve [AUC]) and calibration. External validation was done in a cohort of patients with primary melanomas who underwent SLNB between Jan 30, 1997, and Dec 12, 2013, at the Melanoma Institute Australia (Sydney, NSW, Australia).

FINDINGS

The development cohort consisted of 4071 patients, of whom 2075 (51%) were female and 1996 (49%) were male. 889 (22%) had sentinel node-positive disease and 3182 (78%) had sentinel node-negative disease. The validation cohort comprised 4822 patients, of whom 1965 (41%) were female and 2857 (59%) were male. 891 (18%) had sentinel node-positive disease and 3931 (82%) had sentinel node-negative disease. Median follow-up was 4·8 years (IQR 2·3-7·8) in the development cohort and 5·0 years (2·2-8·9) in the validation cohort. In the development cohort, 5-year recurrence-free survival was 73·5% (95% CI 72·0-75·1) and 5-year melanoma-specific survival was 86·5% (85·3-87·8). In the validation cohort, the corresponding estimates were 66·1% (64·6-67·7) and 83·3% (82·0-84·6), respectively. The final model contained six prognostic factors: sentinel node status, Breslow thickness, presence of ulceration, age at SLNB, primary tumour location, and maximum diameter of the largest sentinel node metastasis. In the development cohort, for the model's prediction of recurrence-free survival, the AUC was 0·80 (95% CI 0·78-0·81); for prediction of melanoma-specific survival, the AUC was 0·81 (0·79-0·84). External validation showed good calibration for both outcomes, with AUCs of 0·73 (0·71-0·75) and 0·76 (0·74-0·78), respectively.

INTERPRETATION

Our prediction model and nomogram accurately predicted patient-specific risk probabilities for 5-year recurrence-free and melanoma-specific survival. These tools could have important implications for clinical decision making when considering adjuvant treatments in patients with high-risk melanomas.

FUNDING

Erasmus Medical Centre Cancer Institute.

Population-based prognostic instrument (SweMR 2.0) for melanoma-specific survival - An ideal tool for individualised treatment decisions for Swedish patients

INTRODUCTION

The prognosis for patients with melanoma has improved due to better treatments in recent years and updated tools to accurately predict an individual's risk are warranted. This study aims to describe a prognostic instrument for patients with cutaneous melanoma and its potential as a clinical device for treatment decisions.

METHODS

Patients with localised invasive cutaneous melanoma diagnosed in 1990-2021 with data on tumour thickness were identified from the population-based Swedish Melanoma Registry. The parametric Royston-Parmar (RP) method was used to estimate melanoma-specific survival (MSS) probabilities. Separate models were constructed for patients (≤1 mm) and (>1 mm) and prognostic groups were created based on all combinations of age, sex, tumour site, tumour thickness, absence/presence of ulceration, histopathologic type, Clark's level of invasion, mitoses and sentinel lymph node (SLN) status.

RESULTS

In total, 72 616 patients were identified, 41 764 with melanoma ≤1 mm and 30 852 with melanoma >1 mm. The most important variable was tumour thickness for both (≤1 mm) and (>1 mm), that explained more than 50% of the survival. The second most important variables were mitoses (≤1 mm) and SLN status (>1 mm). The prognostic instrument successfully created probabilities for >30 000 prognostic groups.

CONCLUSIONS

The Swedish updated population-based prognostic instrument, predicts MSS survival up to 10 years after diagnosis. The prognostic instrument gives more representative and up-to-date prognostic information for Swedish patients with primary melanoma than the present AJCC staging. Additional to clinical use and the adjuvant setting, the information retrieved could be used to plan future studies.

Online prediction tools for melanoma survival: A comparison

BACKGROUND

Breslow thickness, patient age and ulceration are the three most valuable clinical and pathological predictors of melanoma survival. A readily available reliable online tool that accurately considers these and other predictors could be valuable for clinicians managing melanoma patients.

OBJECTIVE

To compare online melanoma survival prediction tools that request user input on clinical and pathological features.

METHODS

Search engines were used to identify available predictive nomograms. For each, clinical and pathological predictors were compared.

RESULTS

Three tools were identified. The American Joint Committee on Cancer tool inappropriately rated thin tumours as higher risk than intermediate tumours. The University of Louisville tool was found to have six shortcomings: a requirement for sentinel node biopsy, unavailable input of thin melanoma or patients over 70 years of age and less reliable hazard ratio calculations for age, ulceration and tumour thickness. The LifeMath.net tool was found to appropriately consider tumour thickness, ulceration, age, sex, site and tumour subtype in predicting survival.

LIMITATIONS

The authors did not have access to the base data used to compile various prediction tools.

CONCLUSION

The LifeMath.net prediction tool is the most reliable for clinicians in counselling patients with newly diagnosed primary cutaneous melanoma regarding their survival prospects.

Development and validation of a nomogram incorporating gene expression profiling and clinical factors for accurate prediction of metastasis in patients with cutaneous melanoma following Mohs micrographic surgery

BACKGROUND

There is a need to improve prognostic accuracy for patients with cutaneous melanoma. A 31-gene expression profile (31-GEP) test uses the molecular biology of primary tumors to identify individual patient metastatic risk.

OBJECTIVE

Develop a nomogram incorporating 31-GEP with relevant clinical factors to improve prognostic accuracy.

METHODS

In an IRB-approved study, 1124 patients from 9 Mohs micrographic surgery centers were prospectively enrolled, treated with Mohs micrographic surgery, and underwent 31-GEP testing. Data from 684 of those patients with at least 1-year follow-up or a metastatic event were included in nomogram development to predict metastatic risk.

RESULTS

Logistic regression modeling of 31-GEP results and T stage provided the simplest nomogram with the lowest Bayesian information criteria score. Validation in an archival cohort (n = 901) demonstrated a significant linear correlation between observed and nomogram-predicted risk of metastasis. The resulting nomogram more accurately predicts the risk for cutaneous melanoma metastasis than T stage or 31-GEP alone.

LIMITATIONS

The patient population is representative of Mohs micrographic surgery centers. Sentinel lymph node biopsy was not performed for most patients and could not be used in the nomogram.

CONCLUSIONS

Integration of 31-GEP and T stage can gain clinically useful prognostic information from data obtained noninvasively.

Stage IIIa Melanoma and Impact of Multiple Positive Lymph Nodes on Survival

BACKGROUND

For patients with cutaneous melanoma, having >1 positive lymph node (LN) is associated with worse survival. We hypothesized that for stage IIIA patients, N2a disease (2 to 3 positive LN) would be associated with a worse prognosis compared to those with N1a disease (1 positive LN).

STUDY DESIGN

Stage IIIA melanoma patients in the NCDB Participant User File from 2010 to 2016 were analyzed. Overall survival (OS) between N1a and N2a patients was compared. Subgroup analyses were made between patients undergoing sentinel lymph node (SLN) biopsy alone and those undergoing subsequent completion lymph node dissection (CLND). A separate post hoc analysis of T2a patients undergoing SLN biopsy and CLND from a prospective multicenter randomized clinical trial was performed to validate the findings.

RESULTS

Records of 2,305 IIIA patients were evaluated. In an adjusted survival model, N2a disease was an independent risk factor for worse OS (hazard ratio [HR] 1.56, p = 0.0052). In the subgroup analysis, there was no difference in OS between N1a and N2a disease for patients who underwent SLN biopsy without CLND (p = 0.59), but there was a significant difference in OS for patients who underwent SLN biopsy plus CLND (p = 0.0009). The separate clinical trial database confirmed that for patients with SLN-only disease, there was no difference in OS between N1a and N2a disease.

CONCLUSIONS

For stage IIIA melanoma patients, the distribution of micrometastatic lymph node disease (SLN or non-SLN), rather than the absolute number of SLNs, should be considered when individualizing adjuvant therapy recommendations.

The Sunbelt Melanoma Trial

The Sunbelt Melanoma Trial, a multicenter, prospective randomized clinical study, evaluated the role of high-dose interferon alfa-2b (HDI) therapy for patients with a single positive sentinel lymph node (SLN) metastasis treated with a completion lymph node dissection (CLND). A second protocol in the trial evaluated the prognostic significance of using molecular markers to identify submicroscopic metastases in sentinel lymph nodes that were negative by routine pathologic analysis. The role of CLND with or without adjuvant HDI was evaluated in this group of patients. The results of the study demonstrated that adjuvant HDI offered no survival benefit for patients with a single positive SLN in terms of disease-free or overall survival. Molecular staging using polymerase chain reaction (PCR) for melanoma markers did not identify a high-risk group of patients at increased risk of melanoma recurrence. Additional treatment of these patients who were PCR-positive with either CLND alone or CLND plus HDI did not improve their survival. Additional studies from the Sunbelt Melanoma Trial helped to validate the operational standards of the SLN biopsy procedure and defined the complication rates for both SLN biopsy and CLND. A prognostic risk calculator has been developed from trial data, and the importance of different micrometastatic tumor burden measurements was reported. Although the Sunbelt Melanoma Trial did not demonstrate an improvement in survival with HDI, it is an important trial that highlights the significance of surgeon-initiated randomized clinical trials that incorporate surgical techniques, molecular biomarkers, and adjuvant therapy.

Development and validation of a nomogram to predict recurrence and melanoma-specific mortality in patients with negative sentinel lymph nodes

Background

Patients with melanoma and negative sentinel nodes (SNs) have varying outcomes, dependent on several prognostic factors. Considering all these factors in a prediction model might aid in identifying patients who could benefit from a personalized treatment strategy. The objective was to construct and validate a nomogram for recurrence and melanoma‐specific mortality (MSM) in patients with melanoma and negative SNs.

Methods

A total of 3220 patients with negative SNs were identified from a cohort of 4124 patients from four EORTC Melanoma Group centres who underwent sentinel lymph node biopsy. Prognostic factors for recurrence and MSM were studied with Cox regression analysis. Significant factors were incorporated in the models. Performance was assessed by discrimination (c‐index) and calibration in cross‐validation across the four centres. A nomogram was developed for graphical presentation.

Results

There were 3180 eligible patients. The final prediction model for recurrence and the calibrated model for MSM included three independent prognostic factors: ulceration, anatomical location and Breslow thickness. The c‐index was 0·74 for recurrence and 0·76 for the calibrated MSM model. Cross‐validation across the four centres showed reasonable model performance. A nomogram was developed based on these models. One‐third of the patients had a 5‐year recurrence probability of 8·2 per cent or less, and one‐third had a recurrence probability of 23·0 per cent or more.

Conclusion

A nomogram for predicting recurrence and MSM in patients with melanoma and negative SNs was constructed and validated. It could provide personalized estimates useful for tailoring surveillance strategies (reduce or increase intensity), and selection of patients for adjuvant therapy or clinical trials.

Could personalize care

Variability in Predictions from Online Tools: A Demonstration Using Internet-Based Melanoma Predictors

BACKGROUND

Prognostic models are increasingly being made available online, where they can be publicly accessed by both patients and clinicians. These online tools are an important resource for patients to better understand their prognosis and for clinicians to make informed decisions about treatment and follow-up. The goal of this analysis was to highlight the possible variability in multiple online prognostic tools in a single disease.

METHODS

To demonstrate the variability in survival predictions across online prognostic tools, we applied a single validation dataset to three online melanoma prognostic tools. Data on melanoma patients treated at Memorial Sloan Kettering Cancer Center between 2000 and 2014 were retrospectively collected. Calibration was assessed using calibration plots and discrimination was assessed using the C-index.

RESULTS

In this demonstration project, we found important differences across the three models that led to variability in individual patients' predicted survival across the tools, especially in the lower range of predictions. In a validation test using a single-institution data set, calibration and discrimination varied across the three models.

CONCLUSIONS

This study underscores the potential variability both within and across online tools, and highlights the importance of using methodological rigor when developing a prognostic model that will be made publicly available online. The results also reinforce that careful development and thoughtful interpretation, including understanding a given tool's limitations, are required in order for online prognostic tools that provide survival predictions to be a useful resource for both patients and clinicians.

Surviving cutaneous melanoma: a clinical review of follow-up practices, surveillance, and management of recurrence

The number of melanoma survivors in the United States continues to steadily increase 2.6% per year, while death rates have remained stable over time. Although controversy exists regarding optimal surveillance strategies, recommendations for clinical monitoring are based on tumor stage, tumor phenotype, likelihood of recurrence, prognosis, risk factors, psychosocial impact of disease, and patient well-being. Management guidelines for recurrent disease depend on the type of recurrence: local, satellite/in-transit, regional, or distant metastasis. This article is a current review of the literature concerning melanoma survivorship.

Pathological staging of melanoma

Staging of cancer is a shorthand system of describing the extent of disease. Pathological staging, often called microstaging, uses the methods of histopathology to achieve this goal. Microstaging for melanoma utilizes attributes that are associated with outcome, generally in association with prognostic models that allow for estimation of survival rates, based on large groups of patients with similar tumors. Microstaging can be performed on primary tumors and to a lesser extent on metastases. Attributes that are important in microstaging in primary tumors include, in particular, those that are utilized in the AJCC/UICC staging system. These are, more or less in order of importance, Breslow's thickness, ulceration, and mitogenicity (the presence or absence of mitoses). Other attributes that have relevance to prognosis at least in some well-conducted studies include tumor-infiltrating lymphocytes, lymphovascular invasion, perineural invasion, Clark's level of invasion, the presence or absence of vertical growth phase and of regression, and other attributes. The pathologic interpretation and significance of these "prognostic variables" are discussed in this chapter. In addition, prognostic models including the AJCC staging system are presented in some detail.

Tissue prognostic biomarkers in primary cutaneous melanoma

Cutaneous melanoma (CM) causes the greatest number of skin cancer-related deaths worldwide. Predicting CM prognosis is important to determine the need for further investigation, counseling of patients, to guide appropriate management (particularly the need for postoperative adjuvant therapy), and for assignment of risk status in groups of patients entering clinical trials. Since recurrence rate is largely independent from stages defined by morphological and morphometric criteria, there is a strong need for identification of additional robust prognostic factors to support decision-making processes. Most data on prognostic biomarkers in melanoma have been evaluated in tumor tissue samples by conventional morphology and immunohistochemistry (IHC) as well as DNA and RNA analyses. In the present review, we critically summarize main high-quality studies investigating IHC-based protein biomarkers of melanoma outcome according to Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK)-derived criteria. Pathways have been classified and conveyed in the "biologic road" previously described by Hanahan and Weinberg. Data derived from genomic and transcriptomic technologies have been critically reviewed to better understand if any of investigated proteins or gene signatures should be incorporated into clinical practice or still remain a field of melanoma research. Despite a wide body of research, no molecular prognostic biomarker has yet been translated into clinical practice. Conventional tissue biomarkers, such as Breslow thickness, ulceration, mitotic rate and lymph node positivity, remain the backbone prognostic indicators in melanoma.

Comparison of sentinel lymph node micrometastatic tumor burden measurements in melanoma

BACKGROUND

Multiple methods have been proposed to classify the micrometastatic tumor burden in sentinel lymph nodes (SLN) for melanoma. The purpose of this study was to determine the classification scheme that best predicts nonsentinel node (NSN) metastasis, disease-free survival (DFS), and overall survival (OS).

STUDY DESIGN

A single reviewer reanalyzed tumor-positive SLN from a multicenter, prospective clinical trial of patients with melanoma ≥ 1.0 mm Breslow thickness who underwent SLN biopsy. The following micrometastatic disease burden measurements were recorded: Starz classification, Dewar classification (microanatomic location), maximum diameter of the largest focus of metastasis, maximum tumor area, and sum of all diameters. Univariate and multivariate models and Kaplan-Meier analysis were used to evaluate each classification system.

RESULTS

We reviewed 204 tumor-positive SLNs from 157 patients. On univariate analysis, all criteria except Starz classification were statistically significant risk factors for NSN metastasis. On multivariate analysis, including Breslow thickness, ulceration, age, sex, and NSN status, maximum diameter (using a cut-off of 3 mm) was the only classification system that was an independent risk factor predicting DFS (hazard ratio 2.31, p = 0.0181) and OS (hazard ratio 3.53, p = 0.0005). By Kaplan-Meier analysis, DFS and OS were significantly different among groups using maximum diameter cut-offs of 1 and 3 mm.

CONCLUSIONS

Maximum tumor diameter outperformed other measurements of metastatic tumor burden, including microanatomic tumor location (Dewar classification), Starz classification, maximum tumor area, and sum of all diameters for prediction of survival. Maximum tumor diameter is a simple method of assessing micrometastatic tumor burden that should be reported routinely.

Outcomes and prognostic factors in superficial spreading melanoma

BACKGROUND

Prognostic factors and risk factors for positive sentinel lymph node (SLN) biopsy results are important to identify in superficial spreading melanoma (SSM).

METHODS

A single-center database and a prospective clinical trial database were reviewed for all patients with diagnoses of SSM. Logistic regression, Kaplan-Meier survival analysis, and univariate and multivariate Cox models were used.

RESULTS

A total of 1,643 patients with SSM were identified. Independent risk factors for positive SLN biopsy results were Breslow thickness (BT) ≥2.0 mm, age <60 years, and presence of ulceration. BT ≥2.0 mm, ulceration, lymphovascular invasion, and positive SLN and positive non-SLN biopsy results were independent risk factors for worse disease-free survival. Independent overall survival risk factors included BT ≥2.0 mm, age ≥60 years, ulceration, nonextremity tumor location, lymphovascular invasion, and positive SLN biopsy results.

CONCLUSIONS

BT, ulceration, lymphovascular invasion, and SLN and non-SLN status are important risk factors for SSM.

Melanoma patients with unknown primary site or nodal recurrence after initial diagnosis have a favourable survival compared to those with synchronous lymph node metastasis and primary tumour

Background

A direct comparison of prognosis between patients with regional lymph node metastases (LNM) detected synchronously with the primary melanoma (primary LNM), patients who developed their first LNM subsequently (secondary LNM) and those with initial LNM in melanoma with unknown primary site (MUP) is missing thus far.

Patients and Methods

Survival of 498 patients was calculated from the time point of the first macroscopic LNM using Kaplan Meier and multivariate Cox hazard regression analysis.

Results

Patients with secondary LNM (HR = 0.67; p = 0.009) and those with initial LNM in MUP (HR = 0.45; p = 0.008) had a better prognosis compared to patients with primary LNM (median survival time 52 and 65 vs. 24 months, respectively). A high number of involved nodes, the presence of in-transit/satellite metastases and male gender had an additional independent unfavourable effect.

Conclusions

Survival of patients with LNM in MUP and with secondary LNM is similar and considerably more favourable compared to those with primary LNM. This difference needs to be considered during patient counselling and for stratification purposes in clinical trials. The assumption of an immune privilege of patients with MUP which is responsible for rejection of the primary melanoma, and results in a favourable prognosis is not supported by our data.