The melanoma 'epidemic': lessons from prostate cancer

Overdiagnosis in malignant melanoma: a scoping review

OBJECTIVES

We aimed to systematically identify and scrutinise published empirical evidence about overdiagnosis in malignant melanoma and examine how frequent overdiagnosis of melanoma is and whether this is related to different types of interventions or diagnostic technologies.

DESIGN AND SETTING

Empirical studies that discussed overdiagnosis in malignant melanoma were eligible, including qualitative and quantitative studies in any type of population, age group and geographical location. We excluded studies that did not include empirical data, studies that only mentioned 'overdiagnosis' without addressing it further and studies that used the term overdiagnosis for cases of misdiagnosis or false positives.We developed the search strategy in cooperation with an information specialist. We searched five databases on 21 April 2022: MEDLINE, Embase, CINAHL, PsycINFO and Cochrane Library.This scoping review adheres to The JBI methodology and Prefered Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping reviews (PRISMA-ScR). Two reviewers independently screened titles, abstracts and full texts for inclusion and extracted data from the included studies. The data extracted include study characteristics, population details, research question, the context and the study's main results.

RESULTS

Our search resulted in 1134 potentially relevant studies. 35 studies were included: 29 register studies, 3 cohort studies, 1 case-control study, 1 survey study and 1 randomised controlled trial. Most register studies examined trends in melanoma incidence and/or mortality and found a significant increase in incidence between 0.39% and 6.6% annually and a little or no increase in mortality. Three cohort studies and one case-control study showed that skin screening was associated with increased detection of melanoma; especially in situ or thin invasive melanoma. Three studies estimated the degree of overdiagnosis which ranged from 29% to 60%.

CONCLUSIONS

Epidemiological data suggest a high degree of overdiagnosis in malignant melanoma. Studies that examined the association between skin screening and malignant melanoma all found increased detection of melanomas, mostly thin and in situ melanomas, which raises concern about overdiagnosis.

The influence of the "cancer" label on perceptions and management decisions for low-grade prostate cancer

BACKGROUND

Grade Group 1 (GG1) prostate cancer should be managed with active surveillance (AS). Global uptake of AS remains disappointingly slow and heterogeneous. Removal of cancer labels has been proposed to reduce GG1 overtreatment. We sought to determine the impact of GG1 disease terminology on individual's perceptions and decision making.

METHODS

Discrete choice experiments were conducted on 3 cohorts: healthy men, canonical partners (partners), and patients with GG1 (patients). Participants reported preferences in a series of vignettes with 2 scenarios each, permuting key opinion leader-endorsed descriptors: biopsy (adenocarcinoma, acinar neoplasm, prostatic acinar neoplasm of low malignant potential [PAN-LMP], prostatic acinar neoplasm of uncertain malignant potential), disease (cancer, neoplasm, tumor, growth), management decision (treatment, AS), and recurrence risk (6%, 3%, 1%, <1%). Influence on scenario selection were estimated by conditional logit models and marginal rates of substitution. Two additional validation vignettes with scenarios portraying identical descriptors except the management options were embedded into the discrete choice experiments.

RESULTS

Across cohorts (194 healthy men, 159 partners, and 159 patients), noncancer labels PAN-LMP or prostatic acinar neoplasm of uncertain malignant potential and neoplasm, tumor, or growth were favored over adenocarcinoma and cancer (P < .01), respectively. Switching adenocarcinoma and cancer labels to PAN-LMP and growth, respectively, increased AS choice by up to 17%: healthy men (15%, 95% confidence interval [CI] = 10% to 20%, from 76% to 91%, P < .001), partners (17%, 95% CI = 12% to 24%, from 65% to 82%, P < .001), and patients (7%, 95% CI = 4% to 12%, from 75% to 82%, P = .063). The main limitation is the theoretical nature of questions perhaps leading to less realistic choices.

CONCLUSIONS

"Cancer" labels negatively affect perceptions and decision making regarding GG1. Relabeling (ie, avoiding word "cancer") increases proclivity for AS and would likely improve public health.

Revision of the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis Classification Schema for Melanocytic Lesions: A Consensus Statement

IMPORTANCE

A standardized pathology classification system for melanocytic lesions is needed to aid both pathologists and clinicians in cataloging currently existing diverse terminologies and in the diagnosis and treatment of patients. The Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) has been developed for this purpose.

OBJECTIVE

To revise the MPATH-Dx version 1.0 classification tool, using feedback from dermatopathologists participating in the National Institutes of Health-funded Reducing Errors in Melanocytic Interpretations (REMI) Study and from members of the International Melanoma Pathology Study Group (IMPSG).

EVIDENCE REVIEW

Practicing dermatopathologists recruited from 40 US states participated in the 2-year REMI study and provided feedback on the MPATH-Dx version 1.0 tool. Independently, member dermatopathologists participating in an IMPSG workshop dedicated to the MPATH-Dx schema provided additional input for refining the MPATH-Dx tool. A reference panel of 3 dermatopathologists, the original authors of the MPATH-Dx version 1.0 tool, integrated all feedback into an updated and refined MPATH-Dx version 2.0.

FINDINGS

The new MPATH-Dx version 2.0 schema simplifies the original 5-class hierarchy into 4 classes to improve diagnostic concordance and to provide more explicit guidance in the treatment of patients. This new version also has clearly defined histopathological criteria for classification of classes I and II lesions; has specific provisions for the most frequently encountered low-cumulative sun damage pathway of melanoma progression, as well as other, less common World Health Organization pathways to melanoma; provides guidance for classifying intermediate class II tumors vs melanoma; and recognizes a subset of pT1a melanomas with very low risk and possible eventual reclassification as neoplasms lacking criteria for melanoma.

CONCLUSIONS AND RELEVANCE

The implementation of the newly revised MPATH-Dx version 2.0 schema into clinical practice is anticipated to provide a robust tool and adjunct for standardized diagnostic reporting of melanocytic lesions and management of patients to the benefit of both health care practitioners and patients.

Cancer overdiagnosis: a challenge in the era of screening

"Screening" is a search for preclinical, asymptomatic disease, including cancer. Widespread cancer screening has led to large increases in early-stage cancers and pre-cancers. Ubiquitous public messages emphasize the potential benefits to screening for these lesions based on the underlying assumption that treating cancer at early stages before spread to other organs should make it easier to treat and cure, using more tolerable interventions. The intuition is so strong that public campaigns are sometimes launched without conducting definitive trials directly comparing screening to usual care. An effective cancer screening test should not only increase the incidence of early-stage preclinical disease but should also decrease the incidence of advanced and metastatic cancer, as well as a subsequent decrease in cancer-related mortality. Otherwise, screening efforts may be uncovering a reservoir of non-progressive and very slowly progressive lesions that were not destined to cause symptoms or suffering during the person's remaining natural lifespan: a phenomenon known as "overdiagnosis." We provide here a qualitative review of cancer overdiagnosis and discuss specific examples due to extensive population-based screening, including neuroblastoma, prostate cancer, thyroid cancer, lung cancer, melanoma, and breast cancer. The harms of unnecessary diagnosis and cancer therapy call for a balanced presentation to people considering undergoing screening, even with a test of accepted benefit, with a goal of informed decision-making. We also discuss proposed strategies to mitigate the adverse sequelae of overdiagnosis.

Not Your Mother's Melanoma: Causes and Effects of Early Melanoma Diagnosis

The year 2022 will herald approximately 100,000 new cases of cutaneous melanoma (CM), and over 7000 deaths from CM. Over the past 40 years, CM incidence has increased nearly six-fold; however, annual mortality has remained relatively constant. These trends encapsulate the phenomenon of overdiagnosis. Increased recognition of indolent lesions that appear histologically malignant may be leading to a melanoma epidemic. Enhanced melanoma awareness, screening efforts, physician uncertainty, medical-legal pressures, and diagnostic scrutiny using tools like immunohistochemical staining, mole mapping, dermoscopy, confocal microscopy, and molecular diagnostics contribute to increased CM diagnosis. As a result, current melanoma staging and treatment guidelines are being challenged. Existing standards fail to accurately identify histologically benign lesions that are lethal or, conversely, histologically malignant lesions that are innocuous. Healthcare systems and, more importantly, patients suffer from this diagnostic ambiguity that leads to the over-treatment of innocuous melanomas and under-treatment of aggressive melanomas. As dermatology continues to experience a shift towards earlier diagnosis of melanoma, management strategies must adapt. Herein, we review factors that may contribute to the increased incidence of melanoma, emphasize deficiencies in current staging systems, and provide insights into the future of melanoma management via precision medicine.

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.

What has changed in the epidemiology of skin melanoma in central Italy during the past 20 years?

The aim was to evaluate changes in skin melanoma incidence and mortality at a population level in central Italy over the past two decades. Skin melanoma incidence rate from 1994 to 2014, were retrieved from the Umbrian Cancer Registry (about 900 000 inhabitants). Changes from 1994-1999 to 2010-2014 in tumour and patient characteristics - sex, age (0-44, 45-64, ≥ 65 years), site (head and neck, trunk, limbs), morphology (superficial spreading, nodular, other), thickness (≤ 1, 1-2, 2-4, > 4) and stage I-II, III-IV - were evaluated. Trends in age-standardized incidence and mortality rates were evaluated as annual percent change. During the past two decades, melanoma incidence significantly increased in both sexes (+6%/year among men and +4%/year among women) and in all ages (0-44 years: + 4.7 and + 4.3; 45-64 years: + 6.1 and + 4.4; ≥65 years: + 6.6 and + 1.7), morphologies, except nodular, and stages. Mortality was stable among men and women. In the area, incidence increased for thin and thick melanoma, showing a true increase, whereas mortality did not increase. Therefore, although improvements in treatment and downstaging effect of early diagnosis have to be considered, a certain degree of overdiagnosis cannot be ruled out.

Clinical validity of a gene expression signature in diagnostically uncertain neoplasms

Aim: Evaluate the accuracy of a 23-gene expression signature in differentiating benign nevi from melanoma by comparing test results with clinical outcomes. Materials & methods: Seven dermatopathologists blinded to gene expression test results and clinical outcomes examined 181 lesions to identify diagnostically uncertain cases. Participants independently recorded diagnoses and responses to questions quantifying diagnostic certainty. Test accuracy was determined through comparison with clinical outcomes (sensitivity and percent negative agreement). Results: Overall, 125 cases fulfilled criteria for diagnostic uncertainty (69.1%; 95% CI: 61.8-75.7%). Test sensitivity and percent negative agreement in these cases were 90.4% (95% CI: 79.0-96.8%) and 95.5% (95% CI: 87.3-99.1%), respectively. Conclusion: The 23-gene expression signature has high diagnostic accuracy in diagnostically uncertain cases when evaluated against clinical outcomes.

Stage-specific incidence trends of melanoma in an English region, 1996-2015: longitudinal analyses of population-based data

The aim of this study was to examine temporal trends in overall and stage-specific incidence of melanoma. Using population-based data on patients diagnosed with melanoma in East Anglia, England, 1996-2015, we estimated age-standardized time trends in annual incidence rates for each stage at diagnosis. Negative binomial regression was used to model trends over time adjusted for sex, age group and deprivation, and to subsequently examine variation in stage-specific trends by sex and age group. The age-standardized incidence increased from 14 to 29 cases/100 000 persons (i.e. 4% annually). Increasing incidence was apparent across all stages but was steepest for stage I [adjusted annual increase: 5%, 95% confidence interval (CI): 5-6%, and more gradual for stage II-IV disease (stage II: 3%, 95% CI: 2-4%; stage III/IV: 2%, 95% CI: 1-3%)]. Stage II-IV increase was apparent in men across age groups and in women aged 50 years or older. Increases in incidence were steeper in those aged 70 years or older, and in men. The findings suggest that both a genuine increase in the incidence of consequential illness and a degree of overdiagnosis may be responsible for the observed increasing incidence trends in melanoma in our population during the study period. They also suggest the potentially lower effectiveness of public health awareness campaigns in men and older people.

The Role of Disease Label in Patient Perceptions and Treatment Decisions in the Setting of Low-Risk Malignant Neoplasms

Importance

The cancer disease label may lead to overtreatment of low-risk malignant neoplasms owing to a patient's emotional response or misunderstanding of prognosis. Decision making should be driven by risks and benefits of treatment and prognosis rather than disease label.

Objective

To determine whether disease label plays a role in patient decision making in the setting of low-risk malignant neoplasms and to determine how the magnitude of the disease-label effect compares with preferences for treatment and prognosis.

Design, Setting, and Participants

A discrete choice experiment conducted using an online survey of 1314 US residents in which participants indicated their preferences between a series of 2 hypothetical vignettes describing the incidental discovery of a small thyroid lesion. Vignettes varied on 3 attributes: disease label (cancer, tumor, or nodule); treatment (active surveillance or hemithyroidectomy); and risk of progression or recurrence (0%, 1%, 2%, or 5%). The independent associations of each attribute with likelihood of vignette selection was estimated with a Bayesian mixed logit model.

Main Outcomes and Measures

The preference weight of the cancer disease label was compared with preference weights for other attributes.

Results

In 1068 predominantly healthy respondents (605 women and 463 men) with a median age of 35 years (range, 18-78 years), the cancer disease label played a considerable role in respondent decision making independent of treatment offered and risk of progression or recurrence. Participants accepted a 4-percentage-point increase in risk of progression or recurrence (from 1% to 5%) to avoid labeling their disease as cancer in favor of nodule (marginal rate of substitution [MRS], 1.0; 95% credible interval [CrI], 0.9-1.1). Preference for the nodule label instead of cancer was similar in magnitude to the preference for active surveillance over surgery (MRS, 1.0; 95% CrI, 0.9-1.1).

Conclusions and Relevance

Disease label plays a role in patient preference independent of treatment risks or prognosis. Raising the threshold for biopsy or removing the word cancer from the disease label may mitigate patient preference for aggressive treatment of low-risk lesions. Health care professionals should emphasize treatment risks and benefits and natural disease history when supporting treatment decisions for potentially innocuous epithelial malignant neoplasms.

Trends in mortality from cutaneous malignant melanoma in Spain (1982-2016): sex-specific age-cohort-period effects

BACKGROUND

Mortality from malignant cutaneous melanoma increased alarmingly during the second half of the 20th century in Spain and other European countries.

OBJECTIVE

The aim was to analyse sex- and age-specific trends in melanoma mortality in Spain in the period 1982-2016.

METHODS

European age-standardized melanoma mortality rates during the period 1982-2016 were calculated from mortality figures provided by the National Statistics Institute. Joinpoint regressions were used to identify significant points of change in trends and to compute average annual per cent change (AAPC). Age-cohort-period models were fitted to explore the effect of these variables on mortality.

RESULTS

During the period 1982-2016, age-standardized melanoma mortality rates increased in Spain from 0.90 to 1.80 deaths per 100 000 people in men and from 0.64 to 1.11 per 100 000 in women, rising noticeably from 1982 to 1995 in both sexes and in all age groups. From the mid-90s different trends were observed depending on sex and age: there was a decrease in mortality in the population younger than 45 years (AAPC -2 in both sexes) and aged 45-64 years (AAPC -1 among men and -0.2 among women), but in the group over 64 years rates continued to increase (AAPC 1.7 and 0.2, respectively, for men and women). The mortality sex ratio decreased in the younger population but increased in older individuals. A cohort effect was observed with lower mortality in the cohorts born after 1943 in men and 1956 in women. There was also a period effect with decreased mortality rates at the beginning of the 1990s.

CONCLUSIONS

Melanoma mortality rates in Spain increased during the last decades of the 20th century; however, later they stabilized in women and began to decrease in younger cohorts and middle-aged men. Promotion of primary and secondary prevention measures should continue, with particular emphasis on males over 65 years.

Current controversies in early-stage melanoma: Questions on incidence, screening, and histologic regression

In the first article in this continuing medical education series we review controversies and uncertainties relating to the epidemiology and initial diagnosis of localized cutaneous melanoma (ie, stage 0, I, or II). Many of these issues are unsettled because of conflicting evidence. Melanoma incidence appears to be increasing, yet its basis has not been fully explained. Despite the advantages of early detection, the US Preventive Services Task Force does not recommend skin screening for the general population. Occasionally, biopsy specimens of melanoma will show histologic regression, but the prognostic importance of this phenomenon is uncertain. Some practitioners recommend obtaining a sentinel lymph node biopsy specimen for thin melanomas showing regression, although this histologic finding is not part of the staging system for thin melanomas. Our goal is to provide the clinician who cares for patients with (or at risk for) melanoma with up-to-date contextual knowledge to appreciate the multiple sides of each controversy so that they will be better informed to discuss these issues with their patients and their families.

Metastatic melanoma with balloon/histiocytoid cytomorphology after treatment with immunotherapy: A histologic mimic and diagnostic pitfall

Epithelioid cells with foamy cytoplasm (histiocytoid features) are typical histopathologic findings among benign and malignant histiocytic neoplasms such as xanthoma and atypical fibroxanthoma. However, these changes are unusual in melanoma, which is typically composed of nested and variably pigmented atypical epithelioid cells. Here, we report a patient with metastatic melanoma in lymph nodes presenting with prominent balloon cell/histiocytoid features expressing melanocytic markers, after treatment with nivolumab. This report suggests that the spectrum of neoplasms with histiocytoid features should be expanded to include melanoma, a pattern that, to the best of our knowledge, is uncommon, especially in the setting of post-neoadjuvant therapy.

Long-Term Survival of Patients with Thin (T1) Cutaneous Melanomas: A Breslow Thickness Cut Point of 0.8 mm Separates Higher-Risk and Lower-Risk Tumors

BACKGROUND

Counterintuitively, more deaths from melanoma occur among patients with thin (T1) primary melanomas (≤ 1 mm) than among those with thick primary melanoma because the great majority present with T1 tumors. Therefore, it is important to stratify their risk as accurately as possible to guide their management and follow-up. This study sought to explore the relationship between tumor thickness and prognosis for patients with thin primary melanomas.

METHODS

A retrospective, single-institution study investigated 6263 patients with cutaneous melanoma (including 2117 T1 cases) who had a minimum follow-up period of 10 years.

RESULTS

For the entire patient cohort, the 10-year melanoma-specific survival (MSS) rate ranged between 92% for the patients with primary melanomas up to 0.3 mm thick and 32% for those with melanomas thicker than 8 mm. When divided into 25-quantile-thickness groups there was a significant difference in 10-year MSS between the two consecutive groups 0.8 and 0.9 mm; the differences in survival were not significantly different for any other consecutive cut points within the less than or equal to 1 mm thickness range, indicating a biologically-relevant difference in outcome above and below 0.8 mm. For the patients treated initially at the authors' institution, the 10- and 20-year MSS rates for those with tumors up to 0.8 mm thick were respectively 93.4 and 85.7%, and for tumors 0.9 to 1.0 mm, the rates were respectively 81.1 and 71.4%. Only 29.3% of the T1 patients who died of melanoma were deceased within 5 years.

CONCLUSIONS

A naturally occurring thickness cut point of 0.8 mm predicts higher or lower risk for patients with thin primary cutaneous melanomas. Long-term follow-up assessment of patients with T1 melanoma is important because late mortality due to melanoma is more common than early mortality.

MDA5 autoantibody-another indicator of clinical diversity in dermatomyositis

Allenbach and colleagues have recently reported for the first time the results of an intriguing study of the histopathologic, immunopathologic and gene expression differences in muscle biopsy tissue from adult dermatomyositis (DM) patients who do and do not have circulating MDA5 autoantibodies (anti-MDA5). Anti-MDA5 were originally identified in a clinically-defined subset of DM patients whose disease was expressed predominately in the skin for unusually long periods of time without accompanying muscle weakness [i.e., "clinically-amyopathic DM" (CADM)] and were at risk for acute, rapidly-progressive form of interstitial lung disease (ILD). As an academic dermatologist in the United States of America (USA) having a career-long interest in the CADM subset, I would like to share my perspective on the results of the work by Allenbach and colleagues and offer some suggestions for additional study in this area. But to do so most effectively, I first would like to review the clinical concept of CADM and its association with anti-MDA5 antibody production and a potentially-fatal form of (ILD).

State of the science on prevention and screening to reduce melanoma incidence and mortality: The time is now

Answer questions and earn CME/CNE Although overall cancer incidence rates are decreasing, melanoma incidence rates continue to increase about 3% annually. Melanoma is a significant public health problem that exacts a substantial financial burden. Years of potential life lost from melanoma deaths contribute to the social, economic, and human toll of this disease. However, most cases are potentially preventable. Research has clearly established that exposure to ultraviolet radiation increases melanoma risk. Unprecedented antitumor activity and evolving survival benefit from novel targeted therapies and immunotherapies are now available for patients with unresectable and/or metastatic melanoma. Still, prevention (minimizing sun exposure that may result in tanned or sunburned skin and avoiding indoor tanning) and early detection (identifying lesions before they become invasive or at an earlier stage) have significant potential to reduce melanoma incidence and melanoma-associated deaths. This article reviews the state of the science on prevention and early detection of melanoma and current areas of scientific uncertainty and ongoing debate. The US Surgeon General's Call to Action to Prevent Skin Cancer and US Preventive Services Task Force reviews on skin cancer have propelled a national discussion on melanoma prevention and screening that makes this an extraordinary and exciting time for diverse disciplines in multiple sectors-health care, government, education, business, advocacy, and community-to coordinate efforts and leverage existing knowledge to make major strides in reducing the public health burden of melanoma in the United States. CA Cancer J Clin 2016;66:460-480. © 2016 American Cancer Society.

Photothermal cancer therapy by gold-ferrite nanocomposite and near-infrared laser in animal model

Surface plasmon resonance effect of gold nanostructures makes them good candidates for photothermal therapy (PTT) application. Herein, gold-ferrite nanocomposite (GFNC) was synthesized and characterized as a photothermal agent in PTT. The aim of this study was to investigate the effect of GFNC upon laser irradiation on treatment of cancer in mice bearing melanoma cancer. Thirty mice received 1.5 × 10(6) B16/F10 cells subcutaneously. After 1 week, the mice bearing solid tumor were divided into four groups: control group (without any treatment), laser group (received laser irradiation without GFNC injection), GFNC group (only received intratumorally GFNC), and GFNC + laser group (received intratumorally GFNC upon laser irradiation). In GFNC + laser group, 200 μL of fluid, 1.3 × 10(-7) mol L(-1) gold nanoparticles, was injected intratumorally and immediately the site of tumor was exposed to continuous wave diode laser beam (808 nm, 1.6 W cm(-2)) for 15 min. All mice but four were euthanized 24 h after treatment to compare the necrotic surface area histologically by using measuring graticule. Statistical analyses revealed significant differences in necrosis extent for GFNC + laser group, compared to other groups. Four subjects (control group and GFNC + laser group, two mice each) were kept for longitudinal study. Histological analyses and tumor volume measurements of the four subjects indicated that tumor in GFNC + laser group was controlled appropriately. It was concluded that combining an 808-nm laser at a power density of 1.6 W cm(-2) with GFNC has a destruction effect in melanoma cancer cells in an animal model.

Survival of patients with skin melanoma in Europe increases further: Results of the EUROCARE-5 study

BACKGROUND

In Europe skin melanoma (SM) survival has increased over time. The aims were to evaluate recent trends and differences between countries and regions of Europe.

METHODS

Relative survival (RS) estimates and geographical comparisons were based on 241,485 patients aged 15years and over with a diagnosis of invasive SM in Europe (2000-2007). Survival time trends during 1999-2007 were estimated using the period approach, for 213,101 patients. Age, gender, sub-sites and morphology subgroups were considered.

RESULTS

In European patients, estimated 5-year RS was 83% (95% confidence interval, CI 83-84%). The highest values were found for patients resident in Northern (88%; 87-88%) and Central (88%; 87-88%) Europe, followed by Ireland and United Kingdom (UK) (86%; 85-86%) and Southern Europe (83%; 82-83%). The lowest survival was in Eastern Europe (74%; 74-75%). Within regions the intercountry absolute difference in percentage points of RS varied from 4% (North) to 34% (East). RS decreased markedly with patients' age and was higher in women than men. Differences according to SM morphology and skin sub-sites also emerged. Survival has slightly increased from 1999 to 2007, with a small improvement in Northern and the most pronounced improvement in Eastern Europe.

DISCUSSION

SM survival is high and still increasing in European patients. The gap between Northern and Southern and especially Eastern European countries, although still present, diminished over time. Differences in stage distribution at diagnosis may explain most of the geographical differences. However, part of the improvement in survival may be attributed to overdiagnosis from early diagnosis practices.

Tumor Cell Adhesion As a Risk Factor for Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma

PURPOSE

Less than 20% of patients with melanoma who undergo sentinel lymph node (SLN) biopsy based on American Society of Clinical Oncology/Society of Surgical Oncology recommendations are SLN positive. We present a multi-institutional study to discover new molecular risk factors associated with SLN positivity in thin and intermediate-thickness melanoma.

PATIENTS AND METHODS

Gene clusters with functional roles in melanoma metastasis were discovered by next-generation sequencing and validated by quantitative polymerase chain reaction using a discovery set of 73 benign nevi, 76 primary cutaneous melanoma, and 11 in-transit melanoma metastases. We then used polymerase chain reaction to quantify gene expression in a model development cohort of 360 consecutive thin and intermediate-thickness melanomas and a validation cohort of 146 melanomas. Outcome of interest was SLN biopsy metastasis within 90 days of melanoma diagnosis. Logic and logistic regression analyses were used to develop a model for the likelihood of SLN metastasis from molecular, clinical, and histologic variables.

RESULTS

ITGB3, LAMB1, PLAT, and TP53 expression were associated with SLN metastasis. The predictive ability of a model that included these molecular variables in combination with clinicopathologic variables (patient age, Breslow depth, and tumor ulceration) was significantly greater than a model that only considered clinicopathologic variables and also performed well in the validation cohort (area under the curve, 0.93; 95% CI, 0.87 to 0.97; false-positive and false-negative rates of 22% and 0%, respectively, using a 10% cutoff for predicted SLN metastasis risk).

CONCLUSION

The addition of cell adhesion-linked gene expression variables to clinicopathologic variables improves the identification of patients with SLN metastases within 90 days of melanoma diagnosis.