Discordance of histopathologic parameters in cutaneous melanoma: Clinical implications

A clinical impact study of dermatologists' use of diagnostic gene expression profile testing to guide patient management

Aim: Cutaneous melanocytic neoplasms with diagnostic and/or clinical ambiguity pose patient management challenges. Methods: Six randomized case scenarios with diagnostic/clinical uncertainty were described with/without a benign or malignant diagnostic gene expression profile (GEP) result. Results: Clinical impact was assessed by reporting the mean increase/decrease of management changes normalized to baseline (n = 32 dermatologists). Benign GEP results prompted clinicians to decrease surgical margins (84.2%). Malignant GEP results escalated surgical excision recommendations (100%). A majority (72.2%) reduced and nearly all (98.9%) increased follow-up frequency for benign or malignant GEP results, respectively. There was an overall increase in management plan confidence with GEP results. Conclusion: Diagnostic GEP tests help guide clinical decision-making in a variety of diagnostically ambiguous or clinicopathologically discordant scenarios.

Diagnostic error, uncertainty, and overdiagnosis in melanoma

Diagnostic error can be defined as deviation from a gold standard diagnosis, typically defined in terms of expert opinion, although sometimes in terms of unexpected events that might occur in follow-up (such as progression and death from disease). Although diagnostic error does exist for melanoma, deviations from gold standard diagnosis, certainly among appropriately trained and experienced practitioners, are likely to be the result of uncertainty and lack of specific criteria, and differences of opinion, rather than lack of diagnostic skills. In this review, the concept of diagnostic error will be considered in relation to diagnostic uncertainty, and the concept of overdiagnosis in melanoma will be presented and discussed.

Impact of second histopathological review of melanocytic skin lesions at a melanoma reference center in Brazil

BACKGROUND

After the biopsy of a suspicious melanocytic lesion, patients depend on the pathologist's precision of specimen evaluation.

METHODS

We assessed the agreement between histopathological reports made by general pathologists and reviewed by a dermatopathologist to evaluate the impact on the patient's management.

RESULTS

In 79 cases analyzed, underdiagnosis was observed in 21.6% and overdiagnosis in 17.7%, resulting in changes in the patients' conduct. The assessment of the Clark level, ulceration and histological type showed mild agreement (P<0.001); the Breslow thickness, surgical margin, and staging showed moderate agreement (P<0.001).

CONCLUSIONS

A dermatopathologist's review should be incorporated into the routine of reference services for pigmented lesions.

Detection of cutaneous malignant melanoma using RNA sampled by tape strips: A study protocol

Background

Cutaneous malignant melanoma (CMM) is curable if detected in its early stages. However, the clinical recognition of CMM is challenging. An American research group has shown promising results in detecting CMM based on RNA profiles sampled from suspicious lesions with tape strips. We aim to further develop this technique and validate if RNA profiles sampled with tape strips can detect CMM.

Methods

This prospective cohort study will include approximately 200 lesions clinically suspected of CMM requiring surgical removal. Tape stripping of the lesions will be performed just before surgical excision. Subsequently, RNA on the tape strips is analyzed using quantitative real-time polymerase chain reaction with TaqMan technology. The results are combined into a binary outcome where positive indicates CMM and negative indicates no CMM. The histopathological diagnosis of the lesions will be used as the gold standard. The main outcome is the results of the RNA test and the histopathological diagnosis, which, combined, provide the sensitivity and specificity of the test.

Discussion

The accuracy of the clinical examination in CMM diagnostics is limited. This clinical trial will explore the ability to use RNA analysis to improve the management of suspicious lesions by enhancing early diagnostic accuracy. Hopefully, it can reduce the number of benign lesions being surgically removed to rule out CMM and decrease patient morbidity.

Trial registration

The project was approved by The Committee on Health Research Ethics of the Capital Region of Denmark (H-15010559) and registered at the Danish Data Protection Agency (BFH-2015-065).

Expanded evidence that the 31-gene expression profile test provides clinical utility for melanoma management in a multicenter study

OBJECTIVE

National Comprehensive Cancer Network (NCCN) guidelines for cutaneous melanoma (CM) recommend physicians consider increased surveillance for patients who typically have lower melanoma survival rates (stages IIB-IV as determined by the American Joint Committee on Cancer (AJCC), 8th edition). However, up to 15% of patients identified as having a low recurrence risk (stages I-IIA) experience disease recurrence, and some patients identified as having a high recurrence risk will not experience any recurrence. The 31-gene expression profile test (31-GEP) stratifies patient recurrence risk into low (Class 1) and high (Class 2) and has demonstrated risk-appropriate impact on disease management and clinical decisions.

METHODS

Five-year plans for lab work, frequency of clinical visits, and imaging pre- and post-31-GEP test results were assessed for a cohort of 509 stage I-III patients following an interim subset analysis of 247 patients.

RESULTS

After receiving 31-GEP results, 50.6% of patients had a change in management plans in at least one of the following categories-clinical visits, lab work, or surveillance imaging. The changes aligned with the risk predicted by the 31-GEP for 76.1% of patients with a Class 1 result and 78.7% of patients with a Class 2 result. A Class 1 31-GEP result was associated with changes toward low-intensity management recommendations, while a Class 2 result was associated with changes toward high-intensity management recommendations.

CONCLUSION

The 31-GEP can stratify patient recurrence risk in patients with CM, and clinicians understand and apply the prognostic ability of the 31-GEP test to alter patient management in risk-appropriate directions.

Artificial neural network in the discrimination of lung cancer based on infrared spectroscopy

Given the increasing prevalence of lung cancer worldwide, an auxiliary diagnostic method is needed alongside the microscopic examination of biopsy samples, which is dependent on the skills and experience of pathologists. Thus, this study aimed to advance lung cancer diagnosis by developing five (5) artificial neural network (NN) models that can discriminate malignant from benign samples based on infrared spectral data of lung tumors (n = 122; 56 malignant, 66 benign). NNs were benchmarked with classical machine learning (CML) models. Stratified 10-fold cross-validation was performed to evaluate the NN models, and the performance metrics—area under the curve (AUC), accuracy (ACC) positive predictive value (PPV), negative predictive value (NPV), specificity rate (SR), and recall rate (RR)—were averaged for comparison. All NNs were able to outperform the CML models, however, support vector machine is relatively comparable to NNs. Among the NNs, CNN performed best with an AUC of 92.28% ± 7.36%, ACC of 98.45% ± 1.72%, PPV of 96.62% ± 2.30%, NPV of 90.50% ± 11.92%, SR of 96.01% ± 3.09%, and RR of 89.21% ± 12.93%. In conclusion, NNs can be potentially used as a computational tool in lung cancer diagnosis based on infrared spectroscopy of lung tissues.

Breslow thickness 2.0: Why gene expression profiling is a step toward better patient selection for sentinel lymph node biopsies

Risk-stratification of cutaneous melanoma is important. Patients want to know what to expect after diagnosis, and physicians need to decide on a treatment plan. Historically, melanoma that had spread beyond the skin and regional lymph nodes was largely incurable, and the only approach to preventing a bad outcome was surgery. Through the seminal work of Alexander Breslow and Donald Morton, a system was devised to carefully escalate surgery based on primary tumor thickness and sentinel lymph node status. Today, we know that prophylactic lymph node dissections do not improve survival, but we continue to appreciate the prognostic implications of a positive sentinel node and the benefits of removing nodal metastases, which facilitates locoregional disease control. However, the question arises whether we can better select patients for sentinel lymph node biopsies (SLNB) as, currently, 85% of these procedures are negative and non-therapeutic. Here, we argue that gene expression profiling (GEP) of the diagnostic biopsy is a valuable step toward better patient selection when combined with reliable clinicopathologic (CP) information such as patient age and Breslow thickness. Recently, a CP-GEP-based classifier of nodal metastasis risk, the Merlin Assay, has become commercially available. While CP-GEP is still being validated in prospective studies, preliminary data suggest that it is an independent predictor of nodal metastasis, outperforming clinicopathological variables. The hunt is on for Breslow thickness 2.0.

Association of Histologic Regression With a Favorable Outcome in Patients With Stage 1 and Stage 2 Cutaneous Melanoma

Importance

Although regression is commonly observed in cutaneous melanoma, it is uncertain whether it is associated with patient prognosis.

Objective

To determine whether histologically confirmed regression was associated with better or worse survival in patients with primary cutaneous melanoma.

Design, Setting, and Participants

This cohort study analyzed data from 2 large cohorts of adults (one in the Netherlands and the other in Australia) with histologically proven, stage 1 and 2 primary, invasive cutaneous melanoma with known regression status treated between 2000 and 2014, with median follow-up times of 4.5 and 11.1 years for the Dutch and Australian cohorts, respectively. For the Dutch patients, population-based data from PALGA, the Dutch Pathology Registry, were used, and follow-up data were retrieved from the Netherlands Cancer Registry. For the Australian patients, data from the database of a large, specialized melanoma treatment center were used.

Main Outcomes and Measures

Multivariable Cox proportional hazards analyses were performed per cohort to assess recurrence-free survival (RFS) and overall survival (OS), and subgroup analyses according to Breslow thickness category and melanoma subtype were performed.

Results

A total of 17 271 Dutch patients and 4980 Australian patients were included. In both cohorts, survival outcomes were better for patients with disease regression. For Dutch patients, the hazard ratio (HR) for those with disease regression was 0.55 (95% CI, 0.48-0.63; P < .001) for RFS and 0.87 (95% CI, 0.79-0.96; P = .004) for OS; for the Australian patients, the HR was 0.61 (95% CI, 0.52-0.72; P < .001) for RFS and 0.73 (95% CI, 0.64-0.84; P < .001) for OS. Subgroup analyses showed that the presence of regression improved RFS within thin and intermediate Breslow thickness melanomas in both cohorts. For patients with superficial spreading melanoma (SSM) subtype, regression improved RFS and OS in both cohorts. For Dutch patients with SSM, the HR for those with disease regression was 0.54 (95% CI, 0.46-0.63; P < .001) for RFS and 0.86 (95% CI, 0.76-0.96; P = .009) for OS; for the Australian patients with SSM, the HR was 0.67 (95% CI, 0.52-0.85; P = .001) for RFS and 0.72 (95% CI, 0.59-0.88; P = .001) for OS.

Conclusions and Relevance

In 2 large patient cohorts from 2 different continents, regression was a favorable prognostic factor for patients with stage 1 and 2 melanomas, especially in those with thin and intermediate thickness tumors and those with SSM subtype.

Translation of a circulating miRNA signature of melanoma into a solid tissue assay to improve diagnostic accuracy and precision

Aim: Successful treatment of cutaneous melanoma depends on early and accurate diagnosis of clinically suspicious melanocytic skin lesions. Multiple international studies have described the challenge of providing accurate and reproducible histopathological assessments of melanocytic lesions, highlighting the need for new diagnostic tools including disease-specific biomarkers. Previously, a 38-miRNA signature (MEL38) was identified in melanoma patient plasma and validated as a novel biomarker. In this study, MEL38 expression in solid tissue biopsies representing the benign nevi to metastatic melanoma spectrum is examined. Patients & methods: Nanostring digital gene expression assessment of the MEL38 signature was performed on 308 formalin-fixed paraffin-embedded biopsies of nevi, melanoma in situ and invasive melanoma. Genomic data were interrogated using hierarchical clustering, univariate and multivariate statistical approaches. Classification scores computed from the MEL38 signature were analyzed for their association with demographic data and histopathology results, including MPATH-DX class, AJCC disease stage and tissue subtype. Results: The MEL38 score can stratify higher-risk melanomas (MPATH-Dx class V or more advanced) from lower-risk skin lesions (class I-IV) with an area under the curve of 0.97 (p < 0.001). The genomic score ranges from 0 to 10 and is positively correlated with melanoma progression, with an intraclass correlation coefficient of 0.85 with stage 0-IV disease. Using an optimized classification threshold of ≥2.7 accurately identifies higher-risk melanomas with 89% sensitivity and 94% specificity. Multivariate analysis showed the score to be a significant predictor of malignancy, independent of technical and clinical covariates. Application of the MEL38 signature to Spitz nevi reveals an intrasubtype profile, with elements in common to both nevi and melanoma. Conclusion: Melanoma-specific circulating miRNAs maintain their association with malignancy when measured in the hypothesized tissue of origin. The MEL38 signature is an accurate and reproducible metric of melanoma status, based on changes in miRNA expression that occur as the disease develops and spreads. Inclusion of the MEL38 score into routine practice would provide physicians with previously unavailable, personalized genomic information about their patient's skin lesions. Combining molecular biomarker data with conventional histopathology data may improve diagnostic accuracy, healthcare resource utilization and patient outcomes.

Evidence concerning the accusation that melanoma is overdiagnosed

BACKGROUND

Melanoma is one of the most commonly diagnosed malignancies in the United States and is responsible for the majority of deaths from skin cancer.

OBJECTIVE

Since the 1970s, the incidence of melanoma has risen appreciably while melanoma-specific mortality has remained stable. This has raised a debate about potential overdiagnosis of melanoma. Herein, we review temporal trends in melanoma incidence and mortality and explore factors that may contribute to observed trends, including an aging population in the United States, ultraviolet exposure, increased numbers of biopsies by dermatologists and physician extenders, skin cancer screenings, histopathology criteria, and historic underdiagnosis. Additionally, we discuss melanoma overdiagnosis and the extent to which it may contribute to current trends.

METHODS

The literature was reviewed.

RESULTS

Several factors may contribute to an increased incidence of melanoma, including an aging population, ultraviolet exposure, increased skin biopsies, skin cancer screenings, histopathologic criteria, historic underdiagnosis, and current overdiagnosis.

LIMITATIONS

Further studies are required to determine exactly which tumors are being overdiagnosed, and how to improve patient outcomes with adjustment to physician's practice.

CONCLUSION

The rise in the incidence of melanoma observed since the 1970s is likely multifactorial.

Five-year survival in patients with nodular and superficial spreading melanomas in the US population

BACKGROUND

Although superficial spreading melanomas (SSM) are diagnosed as thinner lesions, nodular melanomas (NM) have a more rapid growth rate and are biologically more aggressive compared with other histologic subtypes.

OBJECTIVE

To determine the difference in 5-year relative survival in patients with NM and SSM at the same Breslow depth and TNM stage.

METHODS

A population-based cross-sectional analysis compared the 5-year relative survival of patients with NM and SSM using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)∗Stat software (version 8.2.1-8.3.5). Chi-square tests compared the proportions, and Kaplan-Meier method with Z-score compared 5-year relative survival.

RESULTS

For patients receiving a diagnosis between 2004 and 2009, 5-year relative survival was lower in NM compared with SSM (53.7% vs 87.3%; Z score, -41.35; P < .001). Similarly, for patients receiving a diagnosis between 2010 and 2015, 5-year relative survival was lower in NM compared with SSM (61.5% vs 89.7%; Z score, -2.7078; P < .01). Subgroup analyses showed inferior survival in NM in T1b, and survival differences remained significant after excluding patients with nodal or distant metastases.

CONCLUSIONS

Five-year relative survival is worse in NM compared with SSM especially in T1b, T2a, and T2b melanomas. Melanoma subtype should be taken into consideration when making treatment recommendations.

Global and mitosis-specific interobserver variation in mitotic count scoring and implications for malignant melanoma staging

AIMS

Staging is the gold standard for predicting malignant melanoma outcome but changes in its criteria over time indicate ongoing evolution. One notable recent change from the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual was removal of mitotic count. We explore the extent to which this feature is limited by interobserver error in order to find ways to improve its fitness for use should it be revisited in future staging versions.

METHODS AND RESULTS

In a cohort of 476 patients with melanoma ≤1.0 mm, a mitotic count of 0 versus 1 was significant for metastasis-free survival, but not melanoma-specific or overall survival. In 10 melanomas that were 0.9-1.0 mm thick, the mitotic count intraclass correlation coefficient for histopathologists was 0.58 (moderate agreement). Uniquely, we also assessed agreement for specific putative mitotic figures, identifying precise reasons why specific mitotic figures qualified for scoring or elimination. A kappa score was 0.54 (moderate agreement). We also gathered data on other staging features. Breslow thickness had an intraclass correlation coefficient of 0.41 (moderate agreement) and there was a systematic difference between histopathologists among cases (P = 0.04). Every case had a range that crossed the AJCC8 0.8-mm pT1a/pT1b staging boundary. Ulceration was only identified in two of the 10 cases. For ulceration, kappa agreement score was 0.31 (fair).

CONCLUSION

This study supports the removal of mitotic count from staging, but shows that its scoring is substantially affected by interobserver variation, suggesting that more prescriptive guidelines might have a beneficial impact on its prognostic value.

Technological advances for the detection of melanoma: Advances in molecular techniques

The growth of molecular technologies analyzing skin cells and inherited genetic variations has the potential to address current gaps in both diagnostic accuracy and prognostication in patients with melanoma or in individuals who are at risk for developing melanoma. In the second article in this continuing medical education series, novel molecular technologies are reviewed. These have been developed as adjunct tools for melanoma management and include the Pigmented Lesion Assay, myPath Melanoma, and DecisionDx-Melanoma tests, and genetic testing in patients with a strong familial melanoma history. These tests are commercially available and marketed as ancillary tools for clinical decision-making, diagnosis, and prognosis. We review fundamental principles behind each test, discuss peer-reviewed literature assessing their performance, and highlight the utility and limitations of each assay. The goal of this article is to provide a comprehensive, evidence-based foundation for clinicians regarding the management of patients with difficult pigmented lesions.

Incorporation of dermoscopy improves inter-observer agreement among dermatopathologists in histologic assessment of melanocytic neoplasms

Histopathologic assessment of melanocytic neoplasms is the current gold standard of diagnosis. However, there are well recognized limitations including inter-observer diagnostic discordance. This study aimed to determine if integrating dermoscopy with histopathology of melanocytic neoplasms impacts diagnosis and improves inter-observer agreement. We conducted a prospective cohort study in a pigmented lesion clinic. Consecutive melanocytic lesions were identified for biopsy based on atypical gross or dermoscopic features. Standardized immunohistochemistry and levels were ordered on each specimen. The cases were randomized. Three dermatopathologists blinded to the clinical impression assessed each lesion. The cases were then re-randomized and re-assessed with addition of gross clinical and dermoscopic images. Inter-rater reliability (IRR) using Fleiss' kappa statistic revealed an increase from 0.447 without to 0.496 with dermoscopy amongst all dermatopathologists. The kappa increased from 0.495 before to 0.511 with dermoscopy in separating high-grade atypia or melanoma from moderate atypia or less. In 16 of 136 cases, at least 2 of 3 dermatopathologists favored a diagnosis of melanoma only after dermoscopy. In total, the consensus grade of atypia changed in 24.3% (33/ 136) of cases thereby representing changes to excisional margins and patient follow up. This study is limited by the cohort size. Dermoscopy significantly impacts diagnosis and improves identification of early melanomas in high risk populations and improves inter-observer agreement.

Molecular risk prediction in cutaneous melanoma: A meta-analysis of the 31-gene expression profile prognostic test in 1,479 patients

BACKGROUND

Multiple studies have reported on the accuracy of the prognostic 31-gene expression profile test for cutaneous melanoma. Consistency of the test results across studies has not been systematically evaluated.

OBJECTIVE

To assess the robustness of the prognostic value of the 31-gene expression profile.

METHODS

Raw data were obtained from studies identified from systematic review. A meta-analysis was performed to determine overall effect of the 31-gene expression profile. Clinical outcome metrics for the 31-gene expression profile were compared with American Joint Committee on Cancer staging.

RESULTS

Three studies met inclusion criteria; data from a novel cohort of 211 patients were included (n = 1,479). Five-year recurrence-free and distant metastasis-free survival rates were 91.4% and 94.1% for Class 1A patients and 43.6% and 55.5% for Class 2B patients (P < .0001). Meta-analysis results showed that Class 2 was significantly associated with recurrence (hazard ratio 2.90; P < .0001) and distant metastasis (hazard ratio 2.75; P < .0001). The 31-gene expression profile identified American Joint Committee on Cancer stage I to III patient subsets with high likelihood for recurrence and distant metastasis. Sensitivity was 76% (95% confidence interval 71%-80%) and 76% (95% confidence interval 70%-82%) for each end point, respectively. When 31-gene expression profile and sentinel lymph node biopsy results were considered together, sensitivity and negative predictive value for distant metastasis-free survival were both improved.

CONCLUSION

The 31-gene expression profile test consistently and accurately identifies melanoma patients at increased risk of metastasis, is independent of other clinicopathologic covariates, and augments current risk stratification by reclassifying patients for heightened surveillance who were previously designated as being at low risk.

Internal Pathology Review of Invasive Melanoma: An Academic Institution Experience

BACKGROUND

Prior studies of internal pathology review (IPR) for melanoma have shown that changes in the pathology analysis are common. How these changes impact clinical management of melanoma or how the margin status reports may modify has not been evaluated. Our goal was to determine what changes to staging and surgical management occurred after IPR of newly diagnosed melanomas and to determine how the final surgical pathology report may correlate with the IPR.

METHODS

A retrospective study was conducted from 2014 to 2016 of newly diagnosed invasive melanomas referred to a single National Comprehensive Cancer Network tertiary care center.

RESULTS

A total of 370 cases met inclusion criteria. The most common feature changed after internal review was mitotic rate, in 155 (41.7%) patients, followed by Breslow depth in 99 (26.9%) patients. Tumor staging was changed in 45 (12.2%) patients. The most common change was a T1a lesion being upgraded to a T1b lesion. These tumor staging changes lead to 38 (10.3%) overall staging differences. A biopsy's deep margin status was changed in 27 (7.3%) patients. Outside hospital reports lacked information about deep margin status in 71 (19.2%) of specimens. Based on the National Comprehensive Cancer Network guidelines, 22 (5.9%) patients had changes in their sentinel lymph node biopsy recommendations and one of these patients had a positive node found on pathology. Of those patients who had changes in the T-stage, 16 (4.3%) of them also had changes in the recommended wide local excision radial margin.

CONCLUSIONS

IPR of invasive melanoma leads to both changes in staging and the surgical management of melanoma and should remain an important component of care of melanoma patients at a tertiary referral center.

Pathological review of primary cutaneous malignant melanoma by a specialist skin cancer multidisciplinary team improves patient care in the UK

AIMS

The National Institute for Health and Care Excellence advocated the development of specialist skin cancer multidisciplinary teams (SSMDTs) for the management of higher risk invasive skin cancers in the UK. The interobserver variability in the histopathological assessment of primary cutaneous malignant melanoma (PCMM) is well recognised.

METHODS

We evaluated the discordance rates in the assessment of the histopathological criteria of PCMM based on the eighth American Joint Committee on Cancer (AJCC) melanoma staging system and subsequent change in prognosis and management following pathology review by an SSMDT.

RESULTS

353 cases of PCMM were referred to our SSMDT between April 2015 and May 2016. Cases in which there was a discrepancy in one or more histological parameters following expert review were collected retrospectively. Of 341 eligible cases, there were 94 (27.6%) in which there was an alteration in any parameter. There was interobserver agreement in final diagnosis in 96.8%, Breslow thickness in 86.8%, ulceration in 98.2%, microsatellites in 98.5%, tumour mitotic rate in 88.9%, histological subtype in 92.4%, growth phase in 98.5%, angiolymphatic invasion in 97.7%, perineural invasion in 98.8%, regression in 95.3% and tumour-infiltrating lymphocytes in 95.0%. A corresponding change in AJCC stage occurred in 23 cases (6.7%), with a resulting change in clinical management in 10 cases (2.9%).

CONCLUSIONS

Disagreements in the pathological assessment of PCMM can have significant clinical implications for a small number of patients. Our findings highlight the value of the SSMDT for high-quality care of patients with melanoma in the UK.

Enhanced classifier training to improve precision of a convolutional neural network to identify images of skin lesions

BACKGROUND

In recent months, multiple publications have demonstrated the use of convolutional neural networks (CNN) to classify images of skin cancer as precisely as dermatologists. However, these CNNs failed to outperform the International Symposium on Biomedical Imaging (ISBI) 2016 challenge which ranked the average precision for classification of dermoscopic melanoma images. Accordingly, the technical progress represented by these studies is limited. In addition, the available reports are impossible to reproduce, due to incomplete descriptions of training procedures and the use of proprietary image databases or non-disclosure of used images. These factors prevent the comparison of various CNN classifiers in equal terms.

OBJECTIVE

To demonstrate the training of an image-classifier CNN that outperforms the winner of the ISBI 2016 CNNs challenge by using open source images exclusively.

METHODS

A detailed description of the training procedure is reported while the used images and test sets are disclosed fully, to insure the reproducibility of our work.

RESULTS

Our CNN classifier outperforms all recent attempts to classify the original ISBI 2016 challenge test data (full set of 379 test images), with an average precision of 0.709 (vs. 0.637 of the ISBI winner) and with an area under the receiver operating curve of 0.85.

CONCLUSION

This work illustrates the potential for improving skin cancer classification with enhanced training procedures for CNNs, while avoiding the use of costly equipment or proprietary image data.

Melanoma of the eyelid and periocular skin: Histopathologic classification and molecular pathology

Cutaneous melanoma, a potentially lethal malignancy of the periocular skin, represents only a small proportion of the roughly 87,000 new cases of cutaneous melanoma diagnosed annually in the United States. Most of our understanding of melanoma of the eyelid skin is extrapolated from studies of cutaneous melanoma located elsewhere. Recent years have witnessed major breakthroughs in molecular biology and genomics of cutaneous melanoma, some of which have led to the development of targeted therapies. The molecular insights have also kindled interest in rethinking how cutaneous melanomas are classified and assessed for risk. We provide a synopsis of the epidemiology, histopathologic classification, and clinical experience of eyelid melanoma since 1990 and then review major advances in the molecular biology of cutaneous melanoma, exploring how this impacts our understanding of classification and predicting risk.

Teledermatology: Comparison of Store-and-Forward Versus Live Interactive Video Conferencing

A decreasing number of dermatologists and an increasing number of patients in Western countries have led to a relative lack of clinicians providing expert dermatologic care. This, in turn, has prolonged wait times for patients to be examined, putting them at risk. Store-and-forward teledermatology improves patient access to dermatologists through asynchronous consultations, reducing wait times to obtain a consultation. However, live video conferencing as a synchronous service is also frequently used by practitioners because it allows immediate interaction between patient and physician. This raises the question of which of the two approaches is superior in terms of quality of care and convenience. There are pros and cons for each in terms of technical requirements and features. This viewpoint compares the two techniques based on a literature review and a clinical perspective to help dermatologists assess the value of teledermatology and determine which techniques would be valuable in their practice.

Cognitive and visual diagnostic errors in dermatology: part 1

Sir William Osler famously, and ironically, stated that 'Medicine is a science of uncertainty and an art of probability'. The processes by which each physician metes out diagnostic uncertainty and navigates probabilities in dermatology is far from uniform. While certain ubiquitous cognitive and visual heuristics can enhance diagnostic speed, they also create pitfalls and thinking traps that introduce significant variation in the diagnostic process. Discussed in this part of a two-part article are various cognitive and visual heuristics as they pertain to skin disease, with an introduction and special attention paid to the heuristic methods classically applied by dermatologists. How to best address error and improve our thought processes will be addressed in part 2.

Identification of patients at risk of metastasis using a prognostic 31-gene expression profile in subpopulations of melanoma patients with favorable outcomes by standard criteria

BACKGROUND

A substantial number of patients who relapse and die from cutaneous melanoma (CM) are categorized as being at low risk by traditional staging factors. The 31-gene expression profile (31-GEP) test independently stratifies metastatic risk of patients with CM as low (Class 1, with 1A indicating lowest risk) or high (Class 2,with 2B indicating highest risk).

OBJECTIVE

To assess risk prediction by the 31-GEP test within 3 low-risk (according to the American Joint Committee on Cancer) populations of patients with CM: those who are sentinel lymph node (SLN) negative, those with stage I to IIA tumors, and those with thin (≤1 mm [T1]) tumors.

METHODS

A total of 3 previous validation studies provided a nonoverlapping cohort of 690 patients with 31-GEP results, staging information, and survival outcomes. Kaplan-Meier and Cox regression analysis were performed.

RESULTS

The results included the identification of 70% of SLN-negative patients who experienced metastasis as Class 2, the discovery of reduced recurrence-free survival for patients with thin tumors and Class 2B biology compared with that of those with Class 1A biology (P < .0001); and determination of the 31-GEP test as an independent predictor of risk compared with traditional staging factors in patients with stage I to IIA tumors.

LIMITATIONS

Diagnoses spanned multiple versions of pathologic staging criteria.

CONCLUSIONS

The 31-GEP test identifies high-risk patients who are likely to experience recurrence or die of melanoma within low-risk groups of subpopulations of patients with CM who have SLN-negative disease, stage I to IIA tumors, and thin tumors.

MART-1-labeled melanocyte density and distribution in actinic keratosis and squamous cell cancer in situ: Pagetoid melanocytes are a potential source of misdiagnosis as melanoma in situ

BACKGROUND

Actinic keratosis (AK) and squamous cell carcinoma in-situ (SCCIS) within or near melanoma in situ (MIS) can complicate diagnosis due to overlapping clinical and microscopic features. This study aimed to describe basilar melanocyte density and pagetoid spread in AK and SCCIS for improved diagnostic accuracy.

METHODS

A total of 22 AK and 22 SCCIS biopsies containing a margin of uninvolved epidermis were immunostained with MART-1 (melanoma antigen recognized by T-cells 1). The basilar melanocyte:keratinocyte ratio and the number and distribution of pagetoid melanocytes were compared in AK, SCCIS, and uninvolved epidermis. An in-vitro human skin model was created to assess the impact of keratinocyte atypia on melanocyte distribution.

RESULTS

The median basilar melanocyte:keratinocyte ratio in SCCIS (1:11.49) was lower than in uninvolved epidermis (1:5.59, P = 0.0011), and the ratio in AK (1:6.94) was similar to uninvolved epidermis (P = 0.987). Pagetoid melanocytes were absent in perilesional skin but common in AK (21/22, P < 0.0001) and SCCIS (22/22, P < 0.0001). Pagetoid melanocytes at or above the mid-spinous layer were more common in SCCIS (21/22) vs AK (7/22, P < 0.0001). Pagetoid melanocytes were present in the in-vitro skin model made with neoplastic but not normal keratinocytes.

CONCLUSIONS

Pagetoid melanocytes in AK and SCCIS should be interpreted with caution to avoid overdiagnosis of MIS.

Cutaneous Melanoma-A Long Road from Experimental Models to Clinical Outcome: A Review

Cutaneous melanoma is a complex disorder characterized by an elevated degree of heterogeneity, features that place it among the most aggressive types of cancer. Although significant progress was recorded in both the understanding of melanoma biology and genetics, and in therapeutic approaches, this malignancy still represents a major problem worldwide due to its high incidence and the lack of a curative treatment for advanced stages. This review offers a survey of the most recent information available regarding the melanoma epidemiology, etiology, and genetic profile. Also discussed was the topic of cutaneous melanoma murine models outlining the role of these models in understanding the molecular pathways involved in melanoma initiation, progression, and metastasis.

Concordance and Reproducibility of Melanoma Staging According to the 7th vs 8th Edition of the AJCC Cancer Staging Manual

IMPORTANCE

The recently updated American Joint Committee on Cancer (AJCC) classification of cancer staging, the AJCC Cancer Staging Manual, 8th edition (AJCC 8), includes revisions to definitions of T1a vs T1b or greater. The Melanoma Pathology Study database affords a comparison,of pathologists' concordance and reproducibility in the microstaging of melanoma according to both the existing 7th edition (AJCC 7) and the new AJCC 8.

OBJECTIVE

To compare AJCC 7 and AJCC 8 to examine whether changes to the definitions of T1a and T1b or greater are associated with changes in concordance and reproducibility.

DESIGN SETTING AND PARTICIPANTS

In this diagnostic study conducted as part of the national Melanoma Pathology Study across US states, 187 pathologists interpreting melanocytic skin lesions in practice completed 4342 independent case interpretations of 116 invasive melanoma cases. A consensus reference diagnosis and participating pathologists' interpretations were classified into the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis class IV (T1a) or class V ( T1b) using both the AJCC 7 and AJCC 8 criteria.

MAIN OUTCOMES AND MEASURES

Concordance with consensus reference diagnosis, interobserver reproducibility, and intraobserver reproducibility.

RESULTS

For T1a diagnoses, participating pathologists' concordance with the consensus reference diagnosis increased from 44% (95% CI, 41%-48%) to 54% (95% CI, 51%-57%) using AJCC 7 and AJCC 8 criteria, respectively. The concordance for cases of T1b or greater increased from 72% (95% CI, 69%-75%) to 78% (95% CI, 75%-80%). Intraobserver reproducibility of diagnoses also improved, increasing from 59% (95% CI, 56%-63%) to 64% (95% CI, 62%-67%) for T1a invasive melanoma, and from 74% (95% CI, 71%-76%) to 77% (95% CI, 74%-79%) for T1b or greater invasive melanoma cases.

CONCLUSIONS AND RELEVANCE

Melanoma staging in AJCC 8 shows greater reproducibility and higher concordance with a reference standard. Improved classification of invasive melanoma can be expected after implementation of AJCC 8, suggesting a positive impact on patients. However, despite improvement, concordance and reproducibility remain low.

ECCO essential requirements for quality cancer care: Melanoma

BACKGROUND

ECCO essential requirements for quality cancer care (ERQCC) are explanations and descriptions of challenges, organisation and actions that are necessary to give high-quality care to patients who have a specific type of cancer. They are written by European experts representing all disciplines involved in cancer care. ERQCC papers give oncology teams, patients, policymakers and managers an overview of the elements needed in any healthcare system to provide high quality of care throughout the patient journey. References are made to clinical guidelines and other resources where appropriate, and the focus is on care in Europe.

MELANOMA

ESSENTIAL REQUIREMENTS FOR QUALITY CARE: CONCLUSION: Taken together, the information presented in this paper provides a comprehensive description of the essential requirements for establishing a high-quality service for melanoma. The ERQCC expert group is aware that it is not possible to propose a 'one size fits all' system for all countries, but urges that access to multidisciplinary teams and specialised treatments is guaranteed to all patients with melanoma.

Epidemiological and histopathological aspects of primary cutaneous melanoma in residents of Joinville, 2003-2014

BACKGROUND

The worldwide incidence of cutaneous melanoma (CM) has been continuously increasing over the last decades. Primary and secondary prevention, with attention to risk factors and early diagnosis, remain the cornerstone for reducing the burden of cutaneous melanoma. Detailed information with respect to clinical and pathological data on cutaneous melanoma is scarce in Brazil.

OBJECTIVE

The purpose of our study was to analyze epidemiological and pathological characteristics of primary cutaneous melanoma in Joinville, southern Brazil.

METHODS

Observational, cross-sectional, retrospective study in which 893 reports of primary cutaneous melanoma from the local population were analyzed in the period 2003-2014. The study was approved by the local Ethics and Research Committee.

RESULTS

We observed a female predominance of cutaneous melanoma (56.3%). The age standardized incidence rate of primary cutaneous melanoma for the world population in the period 2003-06 was 11.8 per 100,000 population (CI 95%, 10.3-13.4), and 17.5 (CI 95%, 15.7-19.3) in 2011-14, revealing a significant increase of 48.3% (p < 0,05). Six and a half percent of patients had multiple cutaneous melanomas (mean 2.2 years and a maximum of 10.0 years between diagnoses). We observed significant differences between the location head/neck and cutaneous melanoma in situ, lower limb with Breslow depth S III and upper limb with Breslow depth S I. The comparison of the characteristics of cutaneous melanoma in the elderly and non-elderly (< 60 years old) showed significant differences with respect to all the variables studied.

STUDY LIMITATIONS

Using secondary data source.

CONCLUSION

Joinville has high incidence coefficients for Brazilian standards, showing an increase in the incidence of cutaneous melanoma.

Innovations and Developments in Dermatologic Non-invasive Optical Imaging and Potential Clinical Applications

Most dermatologists are aware of the benefits of dermoscopy, and a few are familiar with laser-scanning confocal microscopy. Beyond confocal, there are fully 11 different categories of optical techniques that have been applied to clinical dermatology. This article first provides a comprehensive tabular overview of all these optical diagnostic technologies and then details 4 of the lesser known innovations that are already available or still in development (laser Doppler and speckle imaging, Raman spectroscopy, multiphoton microscopy, photoacoustic tomography), with some potential applications in clinical dermatology (blood flow monitoring, skin cancer diagnosis, composition measurements in atopic dermatitis, skin rejuvenation measurement, and noninvasive sentinel lymph node assessment in melanoma). These methods present many advantages, being non-invasive, portable, and rapid. The development of optics in biological and biomedical sciences (i.e. biophotonics) requires not only deep insight into the applications but also synergistic collaboration between engineers and clinicians.

Pathologists' diagnosis of invasive melanoma and melanocytic proliferations: observer accuracy and reproducibility study

Objective To quantify the accuracy and reproducibility of pathologists' diagnoses of melanocytic skin lesions.Design Observer accuracy and reproducibility study.Setting 10 US states.Participants Skin biopsy cases (n=240), grouped into sets of 36 or 48. Pathologists from 10 US states were randomized to independently interpret the same set on two occasions (phases 1 and 2), at least eight months apart.Main outcome measures Pathologists' interpretations were condensed into five classes: I (eg, nevus or mild atypia); II (eg, moderate atypia); III (eg, severe atypia or melanoma in situ); IV (eg, pathologic stage T1a (pT1a) early invasive melanoma); and V (eg, ≥pT1b invasive melanoma). Reproducibility was assessed by intraobserver and interobserver concordance rates, and accuracy by concordance with three reference diagnoses.Results In phase 1, 187 pathologists completed 8976 independent case interpretations resulting in an average of 10 (SD 4) different diagnostic terms applied to each case. Among pathologists interpreting the same cases in both phases, when pathologists diagnosed a case as class I or class V during phase 1, they gave the same diagnosis in phase 2 for the majority of cases (class I 76.7%; class V 82.6%). However, the intraobserver reproducibility was lower for cases interpreted as class II (35.2%), class III (59.5%), and class IV (63.2%). Average interobserver concordance rates were lower, but with similar trends. Accuracy using a consensus diagnosis of experienced pathologists as reference varied by class: I, 92% (95% confidence interval 90% to 94%); II, 25% (22% to 28%); III, 40% (37% to 44%); IV, 43% (39% to 46%); and V, 72% (69% to 75%). It is estimated that at a population level, 82.8% (81.0% to 84.5%) of melanocytic skin biopsy diagnoses would have their diagnosis verified if reviewed by a consensus reference panel of experienced pathologists, with 8.0% (6.2% to 9.9%) of cases overinterpreted by the initial pathologist and 9.2% (8.8% to 9.6%) underinterpreted.Conclusion Diagnoses spanning moderately dysplastic nevi to early stage invasive melanoma were neither reproducible nor accurate in this large study of pathologists in the USA. Efforts to improve clinical practice should include using a standardized classification system, acknowledging uncertainty in pathology reports, and developing tools such as molecular markers to support pathologists' visual assessments.

Geographic region: Does it matter in cutaneous melanoma of the head and neck?

OBJECTIVES/HYPOTHESIS

The head and neck are two of the most common locations for cutaneous melanoma. We present the first population-based analysis of geographic differences in anatomic subsite, clinicopathologic and demographical traits, histopathologic subtype, treatment modality, and disease-specific survival (DSS) of cutaneous head and neck melanoma (CHNM).

STUDY DESIGN

Retrospective database analysis.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for cases of CHNM reported between 2000 and 2013. Patients were grouped into East, Midwest, South, and West regions of the United States. Overall incidence, demographic traits, primary tumor site, clinicopathologic traits, histopathologic subtype, treatment modality, and DSS were compared among regions.

RESULTS

There were 49,365 patients with CHNM identified. The West (4.60) and the South (4.42) had significantly higher incidence (per 100,000) than the East (3.84) and Midwest (3.65) (P < .05). DSS was significantly different among regions (P < .0066). The East (5 years: 89.4%, 10 years: 84.1%) had the highest DSS rate, and the South (5 years: 87.0%, 10 years: 81.8%) had the lowest DSS rate. The Midwest (5 years: 88.4%, 10 years: 84.3%) and West (5 years: 88.3%, 10 years: 83.5%) had intermediate DSS. On multivariate analysis, the South had an elevated hazard ratio (1.17, 95% confidence interval: 1.05-1.30) when compared to the West.

CONCLUSIONS

Geographic region may play a significant role in CHNM. Incidence is higher in the South and the West. Incidence, histologic subtype, treatment modality, and DSS vary among regions. DSS is lower in the South than the West, even after accounting for other major prognostic factors.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2763-2769, 2017.

The use of Mohs micrographic surgery (MMS) for melanoma in situ (MIS) of the trunk and proximal extremities

BACKGROUND

Evaluation of the entire surgical margin results in high rates of complete excision, low local recurrence rates, and maximal tissue conservation. Although well recognized for melanoma of the head and neck, few studies have focused exclusively on the trunk and proximal extremities.

OBJECTIVE

We sought to evaluate the efficacy of Mohs micrographic surgery for melanoma in situ (MIS) of the trunk and proximal extremities, and determine adequate excision margins for MIS when total margin evaluation is not used.

METHODS

Long-term outcomes in 882 cases of MIS treated with Mohs micrographic surgery were analyzed and compared with historical controls. Rates of complete excision were determined for increasing surgical margin intervals.

RESULTS

One local recurrence occurred in our cohort (0.1%). Only 83% of MIS were excised with a 6-mm margin. Margins of 9 mm were needed to excise 97% of MIS, statistically equivalent to thin melanomas.

LIMITATIONS

We used a nonrandomized, single-institution, retrospective design.

CONCLUSION

Mohs micrographic surgery may cure the 17% of MIS that exceed traditional excision margins of 5 mm and is a valuable option for these patients. Surgical margins of at least 0.9 cm should be considered for MIS of the trunk and extremities when total margin evaluation is not used.

Variation among pathologists' treatment suggestions for melanocytic lesions: A survey of pathologists

BACKGROUND

The extent of variability in treatment suggestions for melanocytic lesions made by pathologists is unknown.

OBJECTIVE

We investigated how often pathologists rendered suggestions, reasons for providing suggestions, and concordance with national guidelines.

METHODS

We conducted a cross-sectional survey of pathologists. Data included physician characteristics, experience, and treatment recommendation practices.

RESULTS

Of 301 pathologists, 207 (69%) from 10 states (California, Connecticut, Hawaii, Iowa, Kentucky, Louisiana, New Jersey, New Mexico, Utah, and Washington) enrolled. In all, 15% and 7% reported never and always including suggestions, respectively. Reasons for offering suggestions included improved care (79%), clarification (68%), and legal liability (39%). Reasons for not offering suggestions included referring physician preference (48%), lack of clinical information (44%), and expertise (29%). Training and caseload were associated with offering suggestions (P < .05). Physician suggestions were most consistent for mild/moderate dysplastic nevi and melanoma. For melanoma in situ, 18 (9%) and 32 (15%) pathologists made suggestions that undertreated or overtreated lesions based on National Comprehensive Cancer Network (NCCN) guidelines, respectively. For invasive melanoma, 14 (7%) pathologists made treatment suggestions that undertreated lesions based on NCCN guidelines.

LIMITATIONS

Treatment suggestions were self-reported.

CONCLUSIONS

Pathologists made recommendations ranging in consistency. These findings may inform efforts to reduce treatment variability and optimize patterns of care delivery for patients.

Clinical impact of a 31-gene expression profile test for cutaneous melanoma in 156 prospectively and consecutively tested patients

OBJECTIVE

DecisionDx-Melanoma * is a 31-gene expression profile test that predicts the risk of metastasis in patients with primary cutaneous melanoma (CM). This study was designed to ascertain clinical management changes determined by the test outcome, which classifies CM patients being at low (Class 1) or high (Class 2) risk for recurrence.

RESEARCH DESIGN AND METHODS

Medical charts were reviewed from 156 CM patients from six institutions (three dermatology and three surgical oncology practices) who were consecutively tested between May 2013 and December 2015. Clinical management data that were compiled and compared before and after receipt of the 31-gene expression test result included frequency of physical exams, frequency and modality of imaging, and referrals to surgical and medical oncologists.

RESULTS

Forty-two percent of patients were Stage I, 47% were Stage II and 8% were Stage III. Overall, 95 patients (61%) were Class 1 and 61 (39%) were Class 2. Documented changes in management were observed in 82 (53%) patients, with the majority of Class 2 patients (77%) undergoing management changes compared to 37% of Class 1 patients (p < 0.0001 by Fisher's exact test). The majority (77/82, 94%) of these changes were concordant with the risk indicated by the test result (p < 0.0001 by Fisher's exact test), with increased management intensity for Class 2 patients and reduced management intensity for Class 1 patients.

CONCLUSIONS

Molecular risk classification by gene expression profiling has clinical impact and influences physicians to direct clinical management of CM patients. The vast majority of the changes implemented after the receipt of test results were reflective of the low or high recurrence risk associated with the patient's molecular classification. Because follow-up data was not collected for this patient cohort, the study is limited for the assessment of the impact of gene expression profile based management changes on healthcare resource utilization and patient outcome.