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.

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.

Role of Concurrent Ultrasound Surveillance of Sentinel Node-Positive Node Fields in Melanoma Patients Having Routine Cross-Sectional Imaging.

PURPOSE: In sentinel node-positive (SN+ve) melanoma patients, active surveillance with regular ultrasound examination of the node field has become standard, rather than completion lymph node dissection (CLND). A proportion of these patients now receive adjuvant systemic therapy and have routine cross-sectional imaging (computed tomography [CT] or positron emission tomography [PET]/CT). The role of concurrent ultrasound (US) surveillance in these patients is unclear. The purpose of our study was to describe the modality of detection of nodal recurrence in SN+ve node fields. METHODS: SN+ve melanoma patients who did not undergo CLND treated at a single institution from January 1, 2016 to December 31, 2020 were included. RESULTS: A total of 225 SN+ve patients with a median follow-up of 23 months were included. Of these, 119 (53%) received adjuvant systemic therapy. Eighty (36%) developed a recurrence at any site; 24 (11%) recurred first in the SN+ve field, of which 12 (5%) were confirmed node field recurrence only at 2 months follow-up. The nodal recurrences were first detected by ultrasound in seven (3%), CT in seven (3%), and PET/CT in seven (3%) patients. All nodal recurrences evident on US were also evident on PET/CT and vice versa. CONCLUSIONS: The high rate of recurrences outside the node field and the identification of all US-detected nodal recurrences on concurrent cross-sectional imaging modalities suggest that routine concurrent ultrasound surveillance of the node-positive field may be unnecessary for SN+ve melanoma patients having routine cross-sectional imaging.

Clinical management of melanocytic tumours of uncertain malignant potential (MelTUMPs), including melanocytomas: A systematic review and meta-analysis.

Little guidance is currently available for managing patients with melanocytic tumours of uncertain or low malignant potential (MelTUMPs, including melanocytomas), in particular the optimal excision margins and whether to offer sentinel node biopsy (SNB). The objective of this review was to evaluate excision margins and the prognostic utility of SNB by systematic review of the literature and meta-analysis. PRISMA guidelines were followed. Medline, EMBASE and Cochrane databases were searched to October 2021 for studies of patients with MelTUMPs reporting excision margins and/or SNB-positivity. Meta-analysis was performed on the SNB-positivity rate using a random effects model, followed by sensitivity analyses on subgroups. 111 primary studies reported excision margins and/or SNB data for 1962 patients. Follow-up was available for 1649 patients: 1561 (94.7%) were alive without disease at last review, 53 (3.2%) had developed further disease, 29 (1.8%) had died of metastatic disease (melanoma) and six (0.4%) died of unrelated causes. SNB was performed in 837 patients. The pooled positivity rate on meta-analysis was 32% (95% CI: 23-44%). Clinical outcome could be correlated with excision margin in only 171 patients (60% of those with known follow up) and was therefore not analysed further. Evidence indicating the ideal excision margins for MelTUMPs was lacking. SNB had a high positivity rate despite very low rates of recurrence or melanoma-related death. Consequently, SNB should not be offered routinely for MelTUMPs (including melanocytomas), due to its lack of prognostic utility for this tumour type (high certainty of evidence).

Benchmarking Survival Outcomes Following Surgical Management of pT3 and pT4 Cutaneous Squamous Cell Carcinoma of the Head and Neck.

BACKGROUND: pT3/4 head and neck cutaneous squamous cell carcinomas (HNcSCCs) are associated with poor outcomes, including local recurrence, metastasis and death. Whilst surgery remains the standard treatment for advanced HNcSCC, novel systemic therapies, such as immunotherapy, are being used earlier in the treatment paradigm. It is imperative that the clinical outcomes of surgery are clearly described so that conventional and emerging treatment modalities can be better integrated and sequenced in the management of pT3/4 HNcSCC. METHODS: Patients with confirmed pT3/4 HNcSCC undergoing curative surgical resection between 2014-2020 were identified retrospectively from a prospectively maintained research database. The primary outcomes of interest were locoregional control (LRC), disease-specific survival (DSS), and overall survival (OS). The secondary outcome was surgical complication rate. RESULTS: A total of 104 patients (median age 74, range 41-94 years) were included, 90% of which had pT3 tumors; 36.5% received adjuvant radiotherapy. Median follow-up was 24.3 (range 1.0-84.3) months. LRC at 5 years was 62.0%, DSS at 5 years was 83.7%, and OS at 5 years was 71.9%. Median time to recurrence was 8.4 months. LRC was reduced in the presence of margin involvement and previous treatment (radiotherapy/surgery). The major surgical complication rate was 9.6%. CONCLUSIONS: More than 60% of patients treated surgically for pT3/4 head and neck cSCC were alive and free of disease at 5 years posttreatment. High-risk features such as margin involvement and having had previous treatment (radiotherapy/surgery) should be used to guide adjuvant therapy.

Merkel cell carcinoma in situ: A systematic review of prognosis and management.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumour. While dermally invasive MCC is known to have a five-year survival of only 30-40%, the prognosis and management of MCC in situ (MCCis) is not widely reported. OBJECTIVE: We present a systematic review to elucidate the prognosis and management of MCCis. METHODS: We performed a systematic review, searching three databases to 01 June 2021. Case reports, cohort studies, clinical trials and literature reviews were considered for inclusion. RESULTS: We identified 26 cases of MCCis published in the literature with a median age of 74 years and involving 19 males and 7 females. Most cases were on the face and neck (n = 17), followed by upper limb (n = 8) and lower limb (n = 1). Sentinel lymph node biopsy was performed in three patients, and all were negative. One subject underwent adjuvant radiotherapy. No MCCis-associated deaths were reported. CONCLUSION: This review suggests that MCCis has an excellent prognosis with minimal, if any, risk of mortality and a very low risk of dermal invasion and recurrence when treated with wide local excision alone. Sentinel lymph node biopsy is unlikely to be useful for MCCis.

Evaluation of an Integrated Smart Sensor System for Real-Time Characterization and Digitalization of Postoperative Abdominal Drain Output: A Pilot Study.

Background: For centuries, surgeons have relied on surgical drains during postoperative care. Despite all advances in modern medicine and the area of digitalization, as of today, most if not all assessment of abdominal secretions excreted via surgical drains are carried out manually. We here introduce a novel integrated Smart Sensor System (Smart Drain) that allows for real-time characterization and digitalization of postoperative abdominal drain output at the patient's bedside. Methods: A prototype of the Smart Drain was developed using a sophisticated spectrometer for assessment of drain output. The prototype measures 10 × 6 × 6 cm and therefore easily fits at the bedside. At the time of measurement with our Smart Drain, the drain output was additionally sent off to be analyzed in our routine laboratory for typical markers of interest in abdominal surgery such as bilirubin, lipase, amylase, triglycerides, urea, protein, and red blood cells. A total of 45 samples from 19 patients were included. Results: The measurements generated were found to correlate with conventional laboratory measurements for bilirubin (r = .658, P = .000), lipase (r = .490, P = .002), amylase (r = .571, P = .000), triglycerides (r = .803, P = .000), urea (r = .326, P = .033), protein (r = .387, P = .012), and red blood cells (r = .904, P = .000). Conclusions: To our best knowledge, for the first time we describe a device using a sophisticated spectrometer that allows for real-time characterization and digitalization of postoperative abdominal drain output at the patient's bedside.

Survival Outcomes of Salvage Metastasectomy After Failure of Modern-Era Systemic Therapy for Melanoma.

BACKGROUND: Metastasectomy for selected patients with melanoma was associated with improved survival in the era before effective systemic therapy. Emerging evidence shows that these benefits persist even in this era of BRAF-targeted therapy and immune checkpoint inhibitor immunotherapy. This study aimed to evaluate the outcomes of salvage metastasectomy after failure of systemic therapy. METHODS: Stage 3 or 4 melanoma patients with extracranial disease progression after at least 4 weeks of systemic treatment between 2009 and 2020 were identified and categorized as resected to no evidence of disease (NED), non-progressive residual disease (NPRD), or progressive residual disease (PRD). Systemic therapy was stratified into BRAF-targeted therapy, immune checkpoint inhibitor immunotherapy, or both. The end points of overall survival (OS), progression-free survival (PFS), and locoregional disease control (LRC) were assessed using Kaplan-Meier curves. Uni- and multivariable Cox regression procedures were used to examine factors associated with OS, PFS and LRC. RESULTS: The study enrolled 190 patients. Among all the patients, the 5-year OS from metastatectomy was 52%, the 3-year PFS was 21%, and the 5-year LRC was 61%. After resection to NED, NPRD, and PRD, the 5-year OS values were 69%, 62% and 8%, respectively. Fewer lines of preoperative therapy, use of preoperative immunotherapy, and resection to NED were predictors of improved OS. After resection to NED, NPRD, and PRD, the 3-year PFS values were 23%, 24% and 10%, and the 5-year LRC values were 61%, 72% and 34%, respectively. CONCLUSIONS: Salvage metastasectomy was associated with durable survival and disease control, particularly after resection to NED, preoperative immunotherapy, and fewer lines of preoperative systemic therapy.

Assessing the immediate impact of COVID-19 on surgical oncology practice: Experience from an NCI-designated Comprehensive Cancer Center in the Northeastern United States.

BACKGROUND: The effects of the coronavirus disease 2019 (COVID-19) pandemic on surgical oncology practice are not yet quantified. The aim of this study was to measure the immediate impact of COVID-19 on surgical oncology practice volume. METHODS: A retrospective study of patients treated at an NCI-Comprehensive Cancer Center was performed. "Pre-COVID" era was defined as January-February 2020 and "COVID" as March-April 2020. Primary outcomes were clinic visits and operative volume by surgical oncology subspecialty. RESULTS: Abouyt 907 new patient visits, 3897 follow-up visits, and 644 operations occurred during the study period. All subspecialties experienced significant decreases in new patient visits during COVID, though soft tissue oncology (Mel/Sarc), gynecologic oncology (Gyn/Onc), and endocrine were disproportionately affected. Telehealth visits increased to 11.4% of all visits by April. Mel/Sarc, Gyn/Onc, and Breast experienced significant operative volume decreases during COVID (25.8%, p = 0.012, 43.6% p < 0.001, and 41.9%, p < 0.001, respectively), while endocrine had no change and gastrointestinal oncology had a slight increase (p = 0.823) in the number of cases performed. CONCLUSIONS: The effects of the COVID-19 pandemic are wide-ranging within surgical oncology subspecialties. The addition of telehealth is a viable avenue for cancer patient care and should be considered in surgical oncology practice.

Biomechanical and physiological differences between synchronous and asynchronous low intensity handcycling during practice-based learning in able-bodied men.

BACKGROUND: Originally, the cranks of a handcycle were mounted with a 180° phase shift (asynchronous). However, as handcycling became more popular, the crank mode switched to a parallel mounting (synchronous) over the years. Differences between both modes have been investigated, however, not into great detail for propulsion technique or practice effects. Our aim is to compare both crank modes from a biomechanical and physiological perspective, hence considering force and power production as a cause of physiological outcome measures. This is done within a practice protocol, as it is expected that motor learning takes place in the early stages of handcycling in novices. METHODS: Twelve able-bodied male novices volunteered to take part. The experiment consisted of a pre-test, three practice sessions and a post-test, which was subsequently repeated for both crank modes in a counterbalanced manner. In each session the participants handcycled for 3 × 4 minutes on a leveled motorized treadmill at 1.94 m/s. Inbetween sessions were 2 days of rest. 3D forces, handlebar and crank angle were measured on the left hand side. Kinematic markers were placed on the handcycle to monitor the movement on the treadmill. Lastly, breath-by-breath spirometry combined with heart-rate were continuously measured. The effects of crank mode and practice-based learning were analyzed using a two way repeated measures ANOVA, with synchronous vs asynchronous and pre-test vs post-test as within-subject factors. RESULTS: In the pre-test, asynchronous handcycling was less efficient than synchronous handcycling in terms of physiological strain, force production and timing. At the post-test, the metabolic costs were comparable for both modes. The force production was, also after practice, more efficient in the synchronous mode. External power production, crank rotation velocity and the distance travelled back and forwards on the treadmill suggest that asynchronous handcycling is more constant throughout the cycle. CONCLUSIONS: As the metabolic costs were reduced in the asynchronous mode, we would advise to include a practice period, when comparing both modes in scientific experiments. For handcycle users, we would currently advise a synchronous set-up for daily use, as the force production is more effective in the synchronous mode, even after practice.

Neurotropic melanoma: an analysis of the clinicopathological features, management strategies and survival outcomes for 671 patients treated at a tertiary referral center.

Neurotropic cutaneous melanoma is a rare melanoma subtype that invades nerves and is often associated with desmoplastic melanoma. Limited data suggest that it has a greater propensity to recur locally, but it is unknown whether its behavior differs from that of other melanoma subtypes, including desmoplastic melanoma. We investigated clinicopathological predictors of outcome in a cohort of 671 patients with neurotropic melanoma to develop evidence-based management recommendations. Patients with primary neurotropic melanoma diagnosed from 1985 to 2013 were identified from the Melanoma Institute Australia database, along with a control cohort of 718 non-neurotropic melanoma patients. Features predictive of sentinel lymph node status, recurrence, melanoma-specific survival and response to adjuvant radiotherapy were sought. Neither local recurrence (hazard ratio: 1.28 (0.73-2.25) P=0.39) nor melanoma-specific survival (hazard ratio: 0.79 (0.55-1.15) P=0.22) were significantly affected by the presence of neurotropism on multivariate analysis. However, there was a markedly reduced likelihood of sentinel node positivity (hazard ratio: 0.61 (0.41-0.89) P=0.01) in neurotropic melanoma patients. Surgical margins ≥8mm halved the recurrence risk compared with <2 mm margins (hazard ratio: 0.46 (0.31-0.68) P<0.001). Additionally, in neurotropic melanoma patients with <8 mm margins, adjuvant radiotherapy halved the recurrence risk (hazard ratio: 0.48 (0.27-0.87) P=0.02). This, the largest study of neurotropic melanoma reported to date, has demonstrated that the presence of neurotropism does not alter the risk of melanoma recurrence or survival but does reduce the likelihood of sentinel node positivity. For successful treatment of neurotropic melanoma, adequate excision margins are of paramount importance. However, when adequate margins cannot be achieved, adjuvant radiotherapy reduces the risk of recurrence.

Poor Adherence to National Clinical Management Guidelines: A Population-Based, Cross-Sectional Study of the Surgical Management of Melanoma in New South Wales, Australia.

BACKGROUND: Standardization of the clinical management of melanoma through the formulation of national guidelines, based on interpretation of the existing evidence and consensus expert opinion, seeks to improve quality of care; however, adherence to national guidelines has not been well studied. METHODS: A population-based, cross-sectional study of the clinical management of all patients with newly notified primary melanomas in the state of New South Wales, Australia, during 2006/2007 was conducted using cancer registry identification and questionnaires completed by treating physicians. RESULTS: Surgical margin guidelines were adhered to in 35% of cases; 45% were over treated and 21% were undertreated. Factors independently associated with non-concordance on multivariate analysis were lower Breslow thickness, lower socio-economic status of the physician's practice location, older physician age, lower physician caseload, and physicians who biopsied the lesion and then referred for definitive management. Complications were not related to over- or under-treatment on multivariate analysis (p = 0.72). Sentinel lymph node biopsy was performed in 17% of patients with invasive melanoma, with the main determinant for selection being a Breslow thickness >0.75 mm. CONCLUSIONS: The low level of concordance with national guidelines for surgical management of melanoma resulted in overtreatment of many patients. However, a fifth of patients were undertreated, which is likely to have resulted in increased locoregional recurrence rates. The better concordance achieved by physicians treating >30 melanomas per year suggests that a minimum caseload threshold for physicians treating melanoma patients would be desirable. High guideline concordance will ensure patients receive optimal care and minimize morbidity and health service costs.

Consensus guidelines from The American Society of Peritoneal Surface Malignancies on standardizing the delivery of hyperthermic intraperitoneal chemotherapy (HIPEC) in colorectal cancer patients in the United States.

BACKGROUND: The American Society of Peritoneal Surface Malignancies (ASPSM) is a consortium of cancer centers performing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). This is a position paper from the ASPSM on the standardization of the delivery of HIPEC. METHODS: A survey was conducted of all cancer centers performing HIPEC in the United States. We attempted to obtain consensus by the modified method of Delphi on seven key HIPEC parameters: (1) method, (2) inflow temperature, (3) perfusate volume, (4) drug, (5) dosage, (6) timing of drug delivery, and (7) total perfusion time. Statistical analysis was performed using nonparametric tests. RESULTS: Response rates for ASPSM members (n = 45) and non-ASPSM members (n = 24) were 89 and 33 %, respectively. Of the responders from ASPSM members, 95 % agreed with implementing the proposal. Majority of the surgical oncologists favored the closed method of delivery with a standardized dual dose of mitomycin for a 90-min chemoperfusion for patients undergoing cytoreductive surgery for peritoneal carcinomatosis of colorectal origin. CONCLUSIONS: This recommendation on a standardized delivery of HIPEC in patients with colorectal cancer represents an important first step in enhancing research in this field. Studies directed at maximizing the efficacy of each of the seven key elements will need to follow.

Correction: Different cadences and resistances in sub-maximal synchronous handcycling in able-bodied men: Effects on efficiency and force application.

[This corrects the article DOI: 10.1371/journal.pone.0183502.].

Long-Term survival across breslow thickness categories: Findings from a Population-Based study of 210,042 Australian melanoma patients.

The prognosis of a patient with a primary cutaneous melanoma is known to be related to the Breslow thickness of their tumor. This study sought to determine long-term (30-year) survival rates for the four AJCC 8th Edition T-categories by analyzing Australian registry data for 210,042 melanoma patients diagnosed from 1982-2014. The 30-year incidence rates of death due to melanoma and non-melanoma causes (with 95% confidence intervals) were 7.1% (CI 6.9-7.3%) and 32.8% (CI 32.3-33.3%), respectively. For T2 melanomas, the corresponding rates were 21.6% (CI 21.0-22.3%) and 35.6% (CI 34.7-36.6%), for T3 melanomas 34.2% (CI 33.4-35.1%) and 39.6% (CI 38.5-40.8%), and for T4 melanomas 44.3% (CI 43.2-45.3%) and 39.6% (CI 38.3-41.0%). A plateau in melanoma-related deaths occurred in T4 patients after 20 years but there were ongoing melanoma-related deaths for the other T-categories beyond 30 years. A progressive rise in the risk of death from other causes occurred across all T-categories.

Population-Based Validation of the MIA and MSKCC Tools for Predicting Sentinel Lymph Node Status.

Importance: Patients with melanoma are selected for sentinel lymph node biopsy (SLNB) based on their risk of a positive SLN. To improve selection, the Memorial Sloan Kettering Cancer Center (MSKCC) and Melanoma Institute Australia (MIA) developed predictive models, but the utility of these models remains to be tested. Objective: To determine the clinical utility of the MIA and MSKCC models. Design, Setting, and Participants: This was a population-based comparative effectiveness research study including 10 089 consecutive patients with cutaneous melanoma undergoing SLNB from the Swedish Melanoma Registry from January 2007 to December 2021. Data were analyzed from May to August 2023. Main Outcomes and Measures,: The predicted probability of SLN positivity was calculated using the MSKCC model and a limited MIA model (using mitotic rate as absent/present instead of count/mm2 and excluding the optional variable lymphovascular invasion) for each patient. The operating characteristics of the models were assessed and compared. The clinical utility of each model was assessed using decision curve analysis and compared with a strategy of performing SLNB on all patients. Results: Among 10 089 included patients, the median (IQR) age was 64.0 (52.0-73.0) years, and 5340 (52.9%) were male. The median Breslow thickness was 1.8 mm, and 1802 patients (17.9%) had a positive SLN. Both models were well calibrated across the full range of predicted probabilities and had similar external area under the receiver operating characteristic curves (AUC; MSKCC: 70.8%; 95% CI, 69.5-72.1 and limited MIA: 69.7%; 95% CI, 68.4-71.1). At a risk threshold of 5%, decision curve analysis indicated no added net benefit for either model compared to performing SLNB for all patients. At risk thresholds of 10% or higher, both models added net benefit compared to SLNB for all patients. The greatest benefit was observed in patients with T2 melanomas using a threshold of 10%; in that setting, the use of the nomograms led to a net reduction of 8 avoidable SLNBs per 100 patients for the MSKCC nomogram and 7 per 100 patients for the limited MIA nomogram compared to a strategy of SLNB for all. Conclusions and Relevance: This study confirmed the statistical performance of both the MSKCC and limited MIA models in a large, nationally representative data set. However, decision curve analysis demonstrated that using the models only improved selection for SLNB compared to biopsy in all patients when a risk threshold of at least 7% was used, with the greatest benefit seen for T2 melanomas at a threshold of 10%. Care should be taken when using these nomograms to guide selection for SLNB at the lowest thresholds.

Predicting Recurrence-Free and Overall Survival for Patients With Stage II Melanoma: The MIA Calculator.

PURPOSE: Improvements in recurrence-free survival (RFS) were demonstrated in two recent randomized trials for patients with sentinel node (SN)-negative stage IIB or IIC melanoma receiving adjuvant systemic therapy (pembrolizumab/nivolumab). However, adverse events also occurred. Accurate individualized prognostic estimates of RFS and overall survival (OS) would allow patients to more accurately weigh the risks and benefits of adjuvant therapy. Since the current American Joint Committee on Cancer eighth edition (AJCC-8) melanoma staging system focuses on melanoma-specific survival, we developed a multivariable risk prediction calculator that provides estimates of 5- and 10-year RFS and OS for these patients. METHODS: Data were extracted from the Melanoma Institute Australia (MIA) database for patients diagnosed with stage II (clinical or pathological) melanoma (n = 3,220). Survival prediction models were developed using multivariable Cox regression analyses (MIA models) and externally validated twice using data sets from the United States and the Netherlands. Each model's performance was assessed using C-statistics and calibration plots and compared with Cox models on the basis of AJCC-8 staging (stage models). RESULTS: The 5-year and 10-year RFS C-statistics were 0.70 and 0.73 (MIA-model) versus 0.61 and 0.60 (stage-model), respectively. For OS, the 5-year and 10-year C-statistics were 0.71 and 0.75 (MIA-model) compared with 0.62 and 0.61 (stage-model), respectively. The MIA models were well calibrated and externally validated. CONCLUSION: The MIA models offer accurate and personalized estimates of both RFS and OS in patients with stage II melanoma even in the absence of pathological staging with SN biopsy. These models were robust on external validations and may be used in everyday practice both with (ideally) and without performing SN biopsy to identify high-risk patients for further management strategies. An online tool will be available at the MIA website (Risk Prediction Tools).