Sex disparities in melanoma outcomes: The role of biology

Molecular Susceptibility and Treatment Challenges in Melanoma

Melanoma is the most aggressive subtype of cancer, with a higher propensity to spread compared to most solid tumors. The application of OMICS approaches has revolutionized the field of melanoma research by providing comprehensive insights into the molecular alterations and biological processes underlying melanoma development and progression. This review aims to offer an overview of melanoma biology, covering its transition from primary to malignant melanoma, as well as the key genes and pathways involved in the initiation and progression of this disease. Utilizing online databases, we extensively explored the general expression profile of genes, identified the most frequently altered genes and gene mutations, and examined genetic alterations responsible for drug resistance. Additionally, we studied the mechanisms responsible for immune checkpoint inhibitor resistance in melanoma.

Sex differences in cancer and immunotherapy outcomes: the role of androgen receptor

Across the wide range of clinical conditions, there exists a sex imbalance where biological females are more prone to autoimmune diseases and males to some cancers. These discrepancies are the combinatory consequence of lifestyle and environmental factors such as smoking, alcohol consumption, obesity, and oncogenic viruses, as well as other intrinsic biological traits including sex chromosomes and sex hormones. While the emergence of immuno-oncology (I/O) has revolutionised cancer care, the efficacy across multiple cancers may be limited because of a complex, dynamic interplay between the tumour and its microenvironment (TME). Indeed, sex and gender can also influence the varying effectiveness of I/O. Androgen receptor (AR) plays an important role in tumorigenesis and in shaping the TME. Here, we lay out the epidemiological context of sex disparity in cancer and then review the current literature on how AR signalling contributes to such observation via altered tumour development and immunology. We offer insights into AR-mediated immunosuppressive mechanisms, with the hope of translating preclinical and clinical evidence in gender oncology into improved outcomes in personalised, I/O-based cancer care.

Analysis and prediction of 5-year survival in patients with cutaneous melanoma: a model-based period analysis

Background

The survival and prognosis of patients are significantly threatened by cutaneous melanoma (CM), which is a highly aggressive disease. It is therefore crucial to determine the most recent survival rate of CM. This study used population-based cancer registry data to examine the 5-year relative survival rate of CM in the US.

Methods

Period analysis was used to assess the relative survival rate and trends of patients with CM in the Surveillance, Epidemiology, and End Results (SEER) database during 2004-2018. And based on the data stratified by age, gender, race and subtype in the SEER database, a generalized linear model was 12established to predict the 5-year relative survival rate of CM patients from 2019 to 2023.

Results

The 5-year relative survival increased to various degrees for both total CM and CM subtypes during the observation period. The improvement was greatest for amelanotic melanoma, increasing from 69.0% to 81.5%. The 5-year overall relative survival rates of CM were 92.9%, 93.5%, and 95.6% for 2004-2008, 2009-2013, and 2014-2018, respectively. Females had a marginally higher survival rate than males for almost all subtypes, older people had lower survival rates than younger people, white patients had higher survival rates than nonwhite ones, and urban locations had higher rates of survival from CM than rural locations did. The survival rate of CM was significantly lower for distant metastasis.

Conclusion

The survival rate of patients with CM gradually improved overall during 2004-2018. With the predicted survival rate of 96.7% for 2019-2023, this trend will still be present. Assessing the changes experienced by patients with CM over the previous 15 years can help in predicting the future course of CM. It also provides a scientific foundation that associated departments can use to develop efficient tumor prevention and control strategies.

Androgen receptor is a determinant of melanoma targeted drug resistance

Melanoma provides a primary benchmark for targeted drug therapy. Most melanomas with BRAFV600 mutations regress in response to BRAF/MEK inhibitors (BRAFi/MEKi). However, nearly all relapse within the first two years, and there is a connection between BRAFi/MEKi-resistance and poor response to immune checkpoint therapy. We reported that androgen receptor (AR) activity is required for melanoma cell proliferation and tumorigenesis. We show here that AR expression is markedly increased in BRAFi-resistant melanoma cells, and in sensitive cells soon after BRAFi exposure. Increased AR expression is sufficient to render melanoma cells BRAFi-resistant, eliciting transcriptional changes of BRAFi-resistant subpopulations, including elevated EGFR and SERPINE1 expression, of likely clinical significance. Inhibition of AR expression or activity blunts changes in gene expression and suppresses proliferation and tumorigenesis of BRAFi-resistant melanoma cells, promoting clusters of CD8+ T cells infiltration and cancer cells killing. Our findings point to targeting AR as possible co-therapeutical approach in melanoma treatment.

Exploratory profiles of phenols, parabens, and per- and poly-fluoroalkyl substances among NHANES study participants in association with previous cancer diagnoses

BACKGROUND

Some hormonally active cancers have low survival rates, but a large proportion of their incidence remains unexplained. Endocrine disrupting chemicals may affect hormone pathways in the pathology of these cancers.

OBJECTIVE

To evaluate cross-sectional associations between per- and polyfluoroalkyl substances (PFAS), phenols, and parabens and self-reported previous cancer diagnoses in the National Health and Nutrition Examination Survey (NHANES).

METHODS

We extracted concentrations of 7 PFAS and 12 phenols/parabens and self-reported diagnoses of melanoma and cancers of the thyroid, breast, ovary, uterus, and prostate in men and women (≥20 years). Associations between previous cancer diagnoses and an interquartile range increase in exposure biomarkers were evaluated using logistic regression models adjusted for key covariates. We conceptualized race as social construct proxy of structural social factors and examined associations in non-Hispanic Black, Mexican American, and other Hispanic participants separately compared to White participants.

RESULTS

Previous melanoma in women was associated with higher PFDE (OR:2.07, 95% CI: 1.25, 3.43), PFNA (OR:1.72, 95% CI: 1.09, 2.73), PFUA (OR:1.76, 95% CI: 1.07, 2.89), BP3 (OR: 1.81, 95% CI: 1.10, 2.96), DCP25 (OR: 2.41, 95% CI: 1.22, 4.76), and DCP24 (OR: 1.85, 95% CI: 1.05, 3.26). Previous ovarian cancer was associated with higher DCP25 (OR: 2.80, 95% CI: 1.08, 7.27), BPA (OR: 1.93, 95% CI: 1.11, 3.35) and BP3 (OR: 1.76, 95% CI: 1.00, 3.09). Previous uterine cancer was associated with increased PFNA (OR: 1.55, 95% CI: 1.03, 2.34), while higher ethyl paraben was inversely associated (OR: 0.31, 95% CI: 0.12, 0.85). Various PFAS were associated with previous ovarian and uterine cancers in White women, while MPAH or BPF was associated with previous breast cancer among non-White women.

IMPACT STATEMENT

Biomarkers across all exposure categories (phenols, parabens, and per- and poly- fluoroalkyl substances) were cross-sectionally associated with increased odds of previous melanoma diagnoses in women, and increased odds of previous ovarian cancer was associated with several phenols and parabens. Some associations differed by racial group, which is particularly impactful given the established racial disparities in distributions of exposure to these chemicals. This is the first epidemiological study to investigate exposure to phenols in relation to previous cancer diagnoses, and the first NHANES study to explore racial/ethnic disparities in associations between environmental phenol, paraben, and PFAS exposures and historical cancer diagnosis.

G protein-coupled receptor GPR68 inhibits lymphocyte infiltration and contributes to gender-dependent melanoma growth

Introduction

Melanoma is a common and aggressive type of skin cancer with rising incidence rate globally. Gender is one of the determining factors, and overall males have a higher risk of developing melanoma as well as worse prognosis. Emerging evidence show that GPR68, a G protein-coupled receptor that is sensitive to acid and mechanical stimulations for cellular microenvironment, plays an important role in tumor biology. However, whether GPR68 is involved in gender-dependent regulation of tumor growth is unclear.

Methods

We established a syngeneic melanoma model in Gpr68-deficient mice and investigated tumor growth in males and females. The GPR68 activation-induced cellular responses of melanocytes, including intracellular calcium dynamics, proliferation and migration were measured. The landscape of tumor-infiltrating immune cells were analyzed by flow cytometry and the expression various cytokines were checked by qRT-PCR.

Results

GPR68 is required for melanoma growth in males but dispensable in females. GPR68 is expressed and functional in B16-F10 melanocytes, but the activity of the receptor does not directly contribute to proliferation and migration of the cells. GPR68 inhibits infiltration of CD45⁺ lymphocytes, CD8⁺ T cells and NK cells in melanoma in male mice, but has no apparent effect in females. Furthermore, GPR68 functionally inhibits the expression of IFNγ in the tumor infiltrating CD8⁺ T cells and NK cells as well as the inflammatory cytokine expression in the spleen in male mice but not in females. Our results show the gender-dependent modulatory effect of GPR68 on tumor-infiltrating immune cells and their tumor-killing capacity.

Discussion

GPR68 is sensor for acid and mechanical stimulations, which are two important factors in the microenvironment associated with tumor growth and metastasis. Our results suggest a prominent role of the receptor molecules in tumor biology in a gender-dependent manner. Since GPCRs are more feasible to develop small molecule drugs compared to transcription factors, our study demonstrates the potential of GPR68 as a novel druggable therapeutic target for melanoma in male patients.

Skin cancer incidence in transgender individuals receiving gender-affirming hormone treatment: a nationwide cohort study in the Netherlands

BACKGROUND

Development of skin cancer, in particular melanoma, has been linked to sex hormones. We aimed to determine the incidence of skin cancer in transgender individuals receiving gender-affirming hormone treatment (GAHT).

METHODS

In this nationwide retrospective cohort study, clinical information of participants who visited our clinic between (the years) 1972 and 2018 and received GAHT was integrated with national pathology and cancer statistics data in order to assess skin cancer incidence. Standardized incidence ratios (SIRs) were calculated.

RESULTS

The cohort consisted of 2,436 trans women and 1,444 trans men. The median age at the start of GAHT was 31 years (IQR 24-42) in trans women and 24 years (IQR 20-32) in trans men. The median follow-up time for trans women was 8 years (IQR 3-18) with a total follow-up time of 29,152 years and 4 years (IQR 2-12) with a total follow-up time of 12,469 years for trans men. Eight trans women were diagnosed with melanoma (SIR 1.80 [95% CI 0.83-3.41] vs. all men; SIR 1.40 [0.65-2.65] vs. all women), and seven developed squamous cell carcinoma (SIR 0.78 [0.34-1.55] vs. all men; SIR 1.15 [0.50-2.27] vs. all women). Two trans men developed melanoma (SIR 1.05 [0.18-3.47] vs. all men; SIR 0.77 [0.14-2.70] vs. all women).

CONCLUSIONS

GAHT did not appear to affect skin cancer incidence in this large cohort of transgender individuals. As skin cancer incidence increases with age and the proportion of elderly subjects is currently limited in this cohort, it will be worthwhile to repeat this analysis in the future.

Melanoma survival by age group: Population-based disparities for adolescent and young adult patients by stage, tumor thickness, and insurance type

BACKGROUND

Melanoma survival literature predominantly represents patients >65 years of age. Study of younger patients may reveal potential age-group-specific differences in survival outcome.

OBJECTIVE

Identify factors associated with differences in melanoma survival in 2 age groups, adolescents and young adults (AYAs; ages 15-39) and older adults (ages 40-64).

METHODS

This population-based registry study included all cases (n = 81,597) of cutaneous melanoma diagnosed at ages 15 to 64 from 2004 to 2015 in California. Age-group-specific multivariable Cox hazard regressions were used.

RESULTS

In the adjusted, age-group-specific models, AYA patients with stage IV melanoma had worse survival (hazard ratio: 20.39, 95% CI: 13.30-31.20) than was observed among older adults (hazard ratio: 10.79, 95% CI: 9.33-12.48). Thicker tumors and public insurance were also associated with worse survival for AYAs than observed in models for older adults. AYAs experienced better survival when detected at earlier stages.

LIMITATIONS

Registry data do not routinely collect behavioral information or family history of melanoma.

CONCLUSIONS

Survival was much worse for AYAs with stage IV melanoma than observed among older adults. To improve AYA survival, early melanoma detection is critical. Greater awareness, suspicion, and screening for AYA melanoma may disrupt delays in diagnosis and reduce the excess burden of mortality from stage IV melanoma in young patients.

Cutaneous melanoma, prostate-specific antigen testing and the subsequent risk of prostate cancer diagnosis: a prospective analysis of the 45 and Up Study

BACKGROUND

The association between cutaneous melanoma and subsequent risk of prostate cancer (PC) was examined in a large population-based cohort study.

METHODS

Male participants in the Sax Institute's 45 and Up Study (Australia) were recruited between 2006 and 2009. Questionnaire data and linked administrative health data from the Centre for Health Record Linkage and Services Australia identified melanomas diagnosed between 1/1/1994 and 12 months before Study recruitment (i.e., between 2005 and 2008), incident PCs, primary healthcare utilisation and prostate-specific antigen (PSA) tests. Men were excluded from the current analyses if they had a recorded PC or other cancer diagnosis other than melanoma and non-melanoma skin cancer prior to recruitment. Multivariable Cox regression was used to estimate hazard ratios (HRs) adjusting for PSA-testing frequency before PC diagnosis.

RESULTS

Of 96,548 eligible men, 1899 were diagnosed with melanoma during the melanoma diagnosis period and 3677 incident PC diagnosed during follow-up (latest date 31/12/2013). Men with melanoma diagnosis had increased risk of a subsequent PC diagnoses (vs. no melanoma; fully adjusted HR = 1.32; 95% CI: 1.09-1.60). There was weak evidence of higher risks of a subsequent PC diagnosis for men diagnosed with more than one melanoma compared to men diagnosed with only one melanoma (p = 0.077), and if first melanoma diagnosis was 10 to 15 years before Study recruitment (fully adjusted HR = 2.05; 95% CI [1.35, 3.12]).

CONCLUSION

Melanoma diagnosis was associated with increased risk of subsequent PC diagnosis, after adjusting for PSA testing and primary healthcare utilisation. While our ability to adjust for PC screening reduced risk of detection bias, we acknowledge that residual confounding from increased medical surveillance after melanoma diagnoses cannot be entirely ruled out.

Gradient differences of immunotherapy efficacy in metastatic melanoma related to sunlight exposure pattern: A population-based study

Background

Immune checkpoint inhibitors (ICIs) have revolutionized metastatic melanoma (MM) treatment in just a few years. Ultraviolet (UV) in sunlight is the most significant environmental cause of melanoma, which is considered to be the main reason for tumor mutation burden (TMB) increase in melanoma. High TMB usually predicts that PD-1 inhibitors are effective. The sunlight exposure pattern of MM might be a clinical feature that matches TMB. The relationship between sunlight exposure patterns and immunotherapy response in MM is unclear. This study aims to investigate the correlation between sunlight exposure patterns and immunotherapy response in MM and establish nomograms that predict 3- and 5-year overall survival (OS) rate.

Methods

We searched the Surveillance, Epidemiology, and End Results (SEER) database and enrolled MM cases from 2005-2016. According to the advent of ICIs in 2011, the era was divided into the non-ICIs era (2005-2010) and the ICIs era (2011-2016). Patients were divided into three cohorts according to the primary site sunlight exposure patterns: head and neck in the first cohort, trunk arms and legs in the second cohort, and acral sites in the third cohort. We compared survival differences for each cohort between the two eras, performed stratified analysis, established nomograms for predicting 3- and 5-year OS rate, and performed internal validation.

Results

Comparing the survival difference between the ICIs and non-ICIs era, head and neck melanoma showed the greatest improvement in survival, with 3- and 5-year OS rate increasing by 10.2% and 9.1%, respectively (P=0.00011). In trunk arms and legs melanoma, the 3- and 5-year OS rate increased by 4.6% and 3.9%, respectively (P<0.0001). There is no improvement in survival in acral melanoma (AM) between the two eras (P=0.78). The receiver operating characteristic (ROC) curve, area under the ROC curve (AUC) and calibration graphs show good discrimination and accuracy of nomograms. Decision curve analysis (DCA) suggests good clinical utility of nomograms.

Conclusions

Based on the classification of sunlight exposure patterns, there is a gradient difference in immunotherapy efficacy for MM. The degree of sunlight exposure is positively correlated with immunotherapy response. The nomograms are sufficiently accurate to predict 3- and 5-year OS rate for MM, allowing for individualized clinical decisions for future clinical work.

Cilt Kanserlerinin Ayırıcı Tanısında İnflamatuar Belirteçlerin Yeri

Aim: The purpose of this study was to evaluate the role of WBC count, NLR, LMR, PLR, Systemic immune-inflammation index (SII) [(platelet count X neutrophil count) \ lymphocyte count] and platelet count (Plt)×NLR in the differential diagnosis of basal cell carcinoma, squamous cell carcinoma, and malignant melanoma and to determine the effect of tumor type, prediction of lymph node metastasis at initial diagnosis and location on these inflammatory markers. Material and Method: Patients who underwent surgery for basal cell carcinoma, squamous cell carcinoma, or malignant melanoma were retrospectively screened. NLR, LMR, PLR, SII and Plt×NLR were calculated. Relationships between tumor type, prediction of lymph node metastasis at initial diagnosis, tumor localization and the inflammatory and hematological parameters of interest were investigated. Tumor location was classified as head and neck and others. Results: A total of 257 patients were included in the study. No statistically significant differences in WBC, NLR, PLR, LMR, SII or Plt×NLR were detected according to tumor location. The patients with squamous cell carcinoma had higher NLR, PRL, SII and Plt×NLR values than those with basal cell carcinoma. The risk of lymph node metastasis at the time of initial diagnosis was 10.3 times higher in patients with PLR levels of 180.7 and higher. The risk of lymph node metastasis detected at initial diagnosis was 8.9 times higher in patients with Plt×NLR of 747 and higher. The risk of lymph node metastasis detected at initial diagnosis was 7.1 times higher in patients with SII of 414 and higher. Conclusion: Inflammatory markers seem to be useful in the differential diagnosis of skin cancers and determined the risk of lymph node metastasis. However, it does not differ according to tumor localization.

Circulating extracellular vesicles expressing PD1 and PD-L1 predict response and mediate resistance to checkpoint inhibitors immunotherapy in metastatic melanoma

BACKGROUND

The immunotherapy with immune checkpoints inhibitors (ICI) has changed the life expectancy in metastatic melanoma (MM) patients. Nevertheless, several patients do not respond hence, the identification and validation of novel biomarkers of response to ICI is of crucial importance. Circulating extracellular vesicles (EVs) such as PD-L1+ EV mediate resistance to anti-PD1, instead the role of PD1+ EV is not fully understood.

METHODS

We isolated the circulating EVs from the plasma of an observational cohort study of 71 metastatic melanoma patients and correlated the amount of PD-L1+ EVs and PD1+ EVs with the response to ICI. The analysis was performed according to the origin of EVs from the tumor and the immune cells. Subsequently, we analysed the data in a validation cohort of 22 MM patients to assess the reliability of identified EV-based biomarkers. Additionally we assessed the involvement of PD1+ EVs in the seizure of nivolumab and in the perturbation of immune cells-mediated killing of melanoma spheroids.

RESULTS

The level of PD-L1+ EVs released from melanoma and CD8+ T cells and that of PD1+ EVs irrespective of the cellular origin were higher in non-responders. The Kaplan-Meier curves indicated that higher levels of PD1+ EVs were significantly correlated with poorer progression-free survival (PFS) and overall survival (OS). Significant correlations were found for PD-L1+ EVs only when released from melanoma and T cells. The multivariate analysis showed that high level of PD1+ EVs, from T cells and B cells, and high level of PD-L1+ EVs from melanoma cells, are independent biomarkers of response. The reliability of PD-L1+ EVs from melanoma and PD1+ EVs from T cells in predicting PFS was confirmed in the validation cohort through the univariate Cox-hazard regression analysis. Moreover we discovered that the circulating EVs captured nivolumab and reduced the T cells trafficking and tumor spheroids killing.

CONCLUSION

Our study identified circulating PD1+ EVs as driver of resistance to anti-PD1, and highlighted that the analysis of single EV population by liquid biopsy is a promising tool to stratify MM patients for immunotherapy.

Sustained androgen receptor signaling is a determinant of melanoma cell growth potential and tumorigenesis

Melanoma susceptibility differs significantly in male versus female populations. Low levels of androgen receptor (AR) in melanocytes of the two sexes are accompanied by heterogeneous expression at various stages of the disease. Irrespective of expression levels, genetic and pharmacological suppression of AR activity in melanoma cells blunts proliferation and induces senescence, while increased AR expression or activation exert opposite effects. AR down-modulation elicits a shared gene expression signature associated with better patient survival, related to interferon and cytokine signaling and DNA damage/repair. AR loss leads to dsDNA breakage, cytoplasmic leakage, and STING activation, with AR anchoring the DNA repair proteins Ku70/Ku80 to RNA Pol II and preventing RNA Pol II-associated DNA damage. AR down-modulation or pharmacological inhibition suppresses melanomagenesis, with increased intratumoral infiltration of macrophages and, in an immune-competent mouse model, cytotoxic T cells. AR provides an attractive target for improved management of melanoma independent of patient sex.

Gender-Dependent Specificities in Cutaneous Melanoma Predisposition, Risk Factors, Somatic Mutations, Prognostic and Predictive Factors: A Systematic Review

BACKGROUND AND AIM

Over the last decades, the incidence of melanoma has been steadily growing, with 4.2% of the population worldwide affected by cutaneous melanoma (CM) in 2020 and with a higher incidence and mortality in men than in women. We investigated both the risk factors for CM development and the prognostic and predictive factors for survival, stratifying for both sex and gender.

METHODS

We conducted a systematic review of studies indexed in PUB-MED, EMBASE, and Scopus until 4 February 2021. We included reviews, meta-analyses, and pooled analyses investigating differences between women and men in CM risk factors and in prognostic and predictive factors for CM survival.

DATA SYNTHESIS

Twenty-four studies were included, and relevant data extracted. Of these, 13 studies concerned potential risk factors, six concerned predictive factors, and five addressed prognostic factors of melanoma.

DISCUSSION

The systematic review revealed no significant differences in genetic predisposition to CM between males and females, while there appear to be several gender disparities regarding CM risk factors, partly attributable to different lifestyles and behavioral habits between men and women. There is currently no clear evidence of whether the mutational landscapes of CM differ by sex/gender. Prognosis is justified by a complex combination of phenotypes and immune functions, while reported differences between genders in predicting the effectiveness of new treatments are inconsistent. Overall, the results emerging from the literature reveal the importance of considering the sex/gender variable in all studies and pave the way for including it towards precision medicine.

CONCLUSIONS

Men and women differ genetically, biologically, and by social construct. Our systematic review shows that, although fundamental, the variable sex/gender is not among the ones collected and analyzed.

Clinical characteristics and prognosis of acral lentiginous melanoma: a single-center series of 211 cases in China

BACKGROUND

Acral lentiginous melanoma (ALM) is common in China with poor prognosis. However, there are only a few studies of ALM in the Asian population. We aimed to summarize and analyze the clinical characteristics, treatment strategy, treatment effect, and prognostic factors of ALM in a Chinese population.

METHODS

We included a total of 249 ALM patients (211 with follow-up data) from a single institution. Demographic, laboratory data, treatment strategy, and prognosis were analyzed.

RESULTS

The ratio of male and female was 1.3 ∶ 1.0. The median age was 58 years old. The majority of patients (70.3%) had lesions on the sole. Trauma history and irritation were associated with lesion size increase in some patients. The prognosis of patients in stage II-III undergoing standard operation was significantly better compared with those without surgical treatment. Patients who did not receive postoperative adjuvant treatment had shorter time to distant metastasis. In multivariable analysis, distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with survival.

CONCLUSIONS

Prognosis for ALM patients was poor in our study. Distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with prognosis.

Sex disparity in skin carcinogenesis and potential influence of sex hormones

Background

Sex or gender disparity in skin cancer has been documented for a long time at the population level. UV radiation (UVR) is a common environmental risk for all three major types of skin cancer: cutaneous melanoma (CM), basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). The underlying mechanism for sex disparity has been largely attributed to sex‐differentiated behaviour patterns related to UVR. Non‐UVR factors such as intrinsic physiological differences have been suggested but remain understudied.

Aims, Materials and Methods

This review summarizes and compares the known sex differences in three skin cancer types with regard to body site distribution and age influence.

Results

We found a similar age‐dependent sex difference pattern in CM and BCC. Specifically, CM and BCC tend to show higher incidence in young women and old men, with a switching age around menopause. The switching age suggests involvement of sex hormones, which has shown controversial influence on skin cancers at epidemiological level. Literatures regarding sex hormone receptors for oestrogen, androgen and progesterone are summarized for potential explanations at molecular level.

Discussion

Overall, more and more evidence suggests non‐UVR factors such as sex hormones play critical roles in skin cancer (especially CM and BCC), yet solid population and molecular evidence are required. Incidences of skin cancer are increasing which suggests limited effect for the current UVR‐avoidance prevention methods.

Conclusion

Fully understanding the causes of sex disparities in incidence is necessary for developing a comprehensive prevention strategy.

uPAR+ extracellular vesicles: a robust biomarker of resistance to checkpoint inhibitor immunotherapy in metastatic melanoma patients

Background

Emerging evidence has highlighted the importance of extracellular vesicle (EV)-based biomarkers of resistance to immunotherapy with checkpoint inhibitors in metastatic melanoma. Considering the tumor-promoting implications of urokinase-type plasminogen activator receptor (uPAR) signaling, this study aimed to assess uPAR expression in the plasma-derived EVs of patients with metastatic melanoma to determine its potential correlation with clinical outcomes.

Methods

Blood samples from 71 patients with metastatic melanoma were collected before initiating immunotherapy. Tumor-derived and immune cell-derived EVs were isolated and analyzed to assess the relative percentage of uPAR⁺ EVs. The associations between uPAR and clinical outcomes, sex, BRAF status, baseline lactate dehydrogenase levels and number of metastatic sites were assessed.

Results

Responders had a significantly lower percentage of tumor-derived, dendritic cell (DC)-derived and CD8⁺ T cell-derived uPAR +EVs at baseline than non-responders. The Kaplan-Meier survival curves for the uPAR⁺EV quartiles indicated that higher levels of melanoma-derived uPAR⁺ EVs were strongly correlated with poorer progression-free survival (p<0.0001) and overall survival (p<0.0001). We also found a statistically significant correlation between lower levels of uPAR⁺ EVs from both CD8⁺ T cells and DCs and better survival.

Conclusions

Our results indicate that higher levels of tumor-derived, DC-derived and CD8⁺ T cell-derived uPAR⁺ EVs in non-responders may represent a new biomarker of innate resistance to immunotherapy with checkpoint inhibitors. Moreover, uPAR⁺ EVs represent a new potential target for future therapeutic approaches.

Oestrogen regulates SOX9 bioavailability by rapidly activating ERK1/2 and stabilising microtubules in a human testis-derived cell line

Nuclear SOX9 is essential for Sertoli cell differentiation and the development of a testis. Exposure of Sertoli cells to exogenous oestrogen causes cytoplasmic retention of SOX9, inhibiting testis development and promoting ovarian development. The cytoplasmic localisation of SOX9 requires a stabilised microtubule network and a key MAPK complex, ERK1/2, is responsive to oestrogen and known to affect the microtubule network. We hypothesised that oestrogen could stabilise microtubules through the activation of ERK1/2 to promote the cytoplasmic retention of SOX9. Treatment of human testis-derived NT2/D1 cells for 30 min with oestrogen rapidly activated ERK1/2, stabilised the microtubule network and increased cytoplasmic localisation of SOX9. The effects of oestrogen on SOX9 and tubulin were blocked by the ERK1/2 inhibitor U0126, demonstrating that ERK1/2 mediates the stabilisation of microtubules and cytoplasmic retention of SOX9 by oestrogen. Together, these data revealed a previously unknown mechanism for oestrogen in impacting MAPK signalling to block SOX9 bioavailability and the differentiation of Sertoli cells.

Vitamin D, melanoma risk, and tumor thickness in PLCO cancer screening trial patients

OBJECTIVE

The incidence of melanoma is increasing. Other than limiting UV exposure, few factors prevent or reduce the risk of melanoma. The aim of this study is to evaluate the relationship between vitamin D intake and melanoma risk in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial.

METHODS

A secondary data analysis was performed on PLCO data. More than 1,300 participants developed melanoma.

RESULTS

Melanoma risk may be increased among men within the highest quartile of vitamin D intake (HR 1.27, 95% CI 0.99, 1.61). Women in the highest quartile of vitamin D intake had a decreased risk of invasive melanoma (HR 0.63, 95% CI 0.41, 0.96). Higher education and being white corresponded with deeper tumors (P < .001).

CONCLUSION

High reported vitamin D intake resulted in an increased risk of melanoma among men. Vitamin D intake yielded a protective effect against invasive melanoma in women.

Characteristics of hospitalized dermatomyositis patients with underlying malignancy: a nationally representative retrospective cohort study

INTRODUCTION

Little is known regarding characteristics of hospitalized dermatomyositis (DM) patients. Understanding the unique characteristics of hospitalized DM patients with underlying malignancy is important in guiding development of specific work-up and treatment algorithms.

OBJECTIVES

We aim to characterize the inpatient burden of DM patients with malignancy (DM malignancy), determine unique characteristics of DM-malignancy inpatients, and assess trends and predictors of cost of care and length of stay for hospitalized DM-malignancy patients.

METHODS

Hospitalized DM patients with and without malignancy were characterized and compared using 2009-2015 National Inpatient Sample. Associated malignancies, risk factors for malignancy, and trends/predictors for cost of care and length of stay were evaluated using multivariable models.

RESULTS

Prevalence of malignancies among hospitalized DM inpatients was 10.9%. Age > 40 years and female sex were significantly associated with increased malignancy risk in DM inpatients. Numerous malignancies were significantly more common in men with DM compared to women, including bronchial, non-Hodgkin's lymphoma, head/neck, bladder, esophageal, kidney, and stomach. The most common malignancies in women with DM were breast and ovarian. Head/neck carcinomas were more common in hospitalized DM patients than previous cohorts evaluating outpatients. Socioeconomic characteristics differed between DM patients with/without malignancy. The presence of underlying malignancy did not affect hospitalization cost, length of stay, or mortality in the hospitalized DM population. The economic burden of hospitalized DM patients is increasing over time.

CONCLUSIONS

DM inpatients with malignancy display numerous differences compared to DM inpatients without malignancy. Further research characterizing hospitalized DM patients is warranted in order to optimize work-up and treatment guidelines for these patients.

Sex differences in cancer mechanisms

We now know that cancer is many different diseases, with great variation even within a single histological subtype. With the current emphasis on developing personalized approaches to cancer treatment, it is astonishing that we have not yet systematically incorporated the biology of sex differences into our paradigms for laboratory and clinical cancer research. While some sex differences in cancer arise through the actions of circulating sex hormones, other sex differences are independent of estrogen, testosterone, or progesterone levels. Instead, these differences are the result of sexual differentiation, a process that involves genetic and epigenetic mechanisms, in addition to acute sex hormone actions. Sexual differentiation begins with fertilization and continues beyond menopause. It affects virtually every body system, resulting in marked sex differences in such areas as growth, lifespan, metabolism, and immunity, all of which can impact on cancer progression, treatment response, and survival. These organismal level differences have correlates at the cellular level, and thus, males and females can fundamentally differ in their protections and vulnerabilities to cancer, from cellular transformation through all stages of progression, spread, and response to treatment. Our goal in this review is to cover some of the robust sex differences that exist in core cancer pathways and to make the case for inclusion of sex as a biological variable in all laboratory and clinical cancer research. We finish with a discussion of lab- and clinic-based experimental design that should be used when testing whether sex matters and the appropriate statistical models to apply in data analysis for rigorous evaluations of potential sex effects. It is our goal to facilitate the evaluation of sex differences in cancer in order to improve outcomes for all patients.

PPARγ inhibition boosts efficacy of PD-L1 Checkpoint Blockade Immunotherapy against Murine Melanoma in a sexually dimorphic manner

Immune checkpoint blockade-based immunotherapy has become standard of care for multiple cancer types. However, the overall response rates among various cancer types still remain unsatisfactory. There is a pressing clinical need to identify combination therapies to improve efficacy of anticancer immunotherapy. We previously showed that pharmacologic inhibition of PPARγ by GW9662 boosts αPD-L1 and αPD-1 antibody efficacy in treating murine mammary tumors. In addition, we defined sexually dimorphic αPD-L1 efficacy in B16 melanoma. Here, we show a sexually dimorphic response to the combination of GW9662 and αPD-L1 immunotherapy in B16 melanoma. Combination effects were observed in female, but not male hosts. Neither female oöphorectomy impairs, nor does male castration rescue the combination effects, suggesting a sex hormone-independent response to this combination therapy. In diet-induced obese females, melanoma growth remained responsive to the combination treatment, albeit less robustly than lean females. These findings are informative for future design and application of immunotherapy-related combination therapy for treating human melanoma patients by taking gender and obesity status into consideration.

National Burden of Hospitalization Due to Cutaneous Melanoma in Adolescents and Young Adults

OBJECTIVES

Although adolescents and young adults (AYA) suffer disproportionately from cutaneous melanoma (CM), little is known regarding the burden of CM leading to hospitalization in AYA. The objective of this study was to elucidate sociodemographic/hospitalization characteristics of AYA CM inpatients, determine which factors lead to the greater length of stay (LOS) and cost of care for AYA CM inpatients, and evaluate trends in the prevalence, LOS, and cost of care for AYA CM hospitalizations.

MATERIALS AND METHODS

A retrospective cohort study of nationally representative data from the 2009 to 2015 National Inpatient Sample. Multivariable survey-weighted logistic regression models were used to determine sociodemographic factors associated with AYA CM hospitalization. Multivariable survey-weighted linear regression models were used to determine characteristics associated with the greater cost of care and LOS in AYA CM inpatients.

RESULTS

A total of 8986 AYA CM inpatients were included in this study. The prevalence of AYA CM hospitalizations is decreasing over time while the cost of care is increasing. On average, AYA CM hospitalizations were 3.3 days long and cost $38,018.40. Controlling for all covariates, male sex, older age, non-Hispanic white race, higher income, private insurance, and elective admissions were associated with AYA hospitalization due to CM (P<0.0001). Male sex was associated with longer LOS (P=0.007) and cost of care (P=0.01) among AYA hospitalized for CM.

CONCLUSIONS

Despite a decreasing prevalence of CM hospitalizations in AYA inpatients, the economic burden of these hospitalizations is increasing. Substantial sex-based differences exist in the inpatient burden of AYA CM. Further research is required to elucidate the causes of these differences and prevent AYA hospitalization due to CM.

Contributions by MC1R Variants to Melanoma Risk in Males and Females

Importance

Recently, the red hair variants of MC1R were found to contribute differently to pigmentation phenotype in males and females.

Objective

To investigate the role of these variants in melanoma risk in males and females separately because carriers of the red hair variants of MC1R are at increased risk of melanoma.

Design, Setting, and Participants

In this hospital-based, case-control study, we evaluated the effect of MC1R and melanoma risk for males and females separately by performing multivariate logistic regression analyses.

Main Outcomes and Measures

Association of MC1R variants and melanoma risk in males and females.

Results

A total of 905 females (473 melanoma cases, 432 controls) and 886 males (518 melanoma cases, 368 controls) were included in the analyses. The mean (SD) age of the study population was 59.2 (15.6). In females, carrying any MC1R red hair variants remained an independent risk factor of melanoma in a multivariable analysis (adjusted odds ratio [OR], 2.19 [95% CI, 1.60-2.99]), whereas in males, only signs of actinic skin damage (lentigines on the back [OR, 2.56; 95% CI, 1.47-4.45; P = .001] and the hands [OR, 2.31; 95% CI, 1.24-4.29; P = .008] and wrinkling on the neck [OR, 2.17; 95% CI, 1.23-3.82; P = .007]) and sunburns (OR, 1.65; 95% CI, 1.12-2.42; P = .01) remained significant risk factors.

Conclusions and Relevance

MC1R variants contribute differently to melanoma risk in males and females. This could be helpful to better classify melanoma risk factors between the sexes.

Characteristics of Patients Hospitalized for Cutaneous Squamous Cell Carcinoma

BACKGROUND

Knowledge regarding the inpatient burden of cutaneous squamous cell carcinoma (cSCC) is limited.

OBJECTIVE

To provide nationally representative estimates for hospitalization characteristics due to cSCC and determine predictors for increased length of stay (LOS) and cost of care.

METHODS/MATERIALS

A retrospective cohort study of the 2009 to 2015 National Inpatient Sample. Weighted multivariate logistic/linear regression models were created to evaluate sociodemographic factors associated with cSCC hospitalization and to assess characteristics associated with cost of care and LOS.

RESULTS

This study included 15,784 cSCC and 255,244,626 non-SCC inpatients (prevalence = 6.2/100,000 inpatients). On average, cSCC hospitalizations lasted 5.8 days and cost $66,841.00. Cutaneous squamous cell carcinoma most often occurred on the scalp (30.57%), face (21.08%), and lower limb (11.93%). Controlling for all other factors, cSCC inpatients presented to larger/urban/teaching hospitals and were most often older non-Hispanic white women. More chronic conditions/diagnoses/procedures and nonwhite race were associated with greater cost of care and LOS. Cost of care and LOS significantly differed between cSCCs of different anatomical sites. The most common procedures performed were skin grafts (27.96%), excisions (25.83%), and lymph node biopsies (11.39%).

CONCLUSION

This study highlights the substantial burden of inpatient cSCC in the United States. Further research is necessary to prevent cSCC hospitalizations and improve inpatient dermatologic care for cSCC.

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.

Sex Differences in Melanoma

PURPOSE OF REVIEW

The goal of this review has been to elucidate the sex differences in cancer incidence and mortality in cutaneous melanoma. We have evaluated biological and behavioral research to determine where the critical questions exist.

RECENT FINDINGS

The most recent findings, through 2015, are exploratory in nature but seem to indicate that the differences are more likely due to biological variations rather than behavioral. While behavioral studies do show that women are more likely than men to seek health care and practice healthy behaviors, these differences are not sufficiently strong to explain the variation in incidence and mortality in cutaneous melanoma. Evolved differences in the immune systems of females and the role of sex steroid hormones in immunomodulation are two promising avenues for research. Studies in mice demonstrate that the newer immunotherapies are more effective in females and sex steroid hormones, such as estrogen receptor beta are inversely associated with tumor aggressiveness while testosterone increases it.

SUMMARY

Our analysis indicates that biological factors need to be investigated more thoroughly to understand the variation in incidence and mortality in cutaneous melanoma. Such understanding could lead to reducing incidence and mortality for both males and females (male incidence is 27.4 per 100,000; female 16.8 per 100,000; male mortality is 3.9 per 100,000; female mortality 1.6 per 100,000). It is most likely that behavioral differences between the sexes cannot account for the preponderance of male mortality. In addition to the important role of genetic factors, it is critical to evaluate further additional biological factors and their interactions with genetics and behavior.

The number and localization of CD68+ and CD163+ macrophages in different stages of cutaneous melanoma

The role of tumor-associated macrophages (TAMs) in cutaneous melanoma is controversial. TAMs include immunogenic and immunosuppressive subtypes, and have distinct functions according to their microanatomical localization. Our aim was to investigate TAMs in benign, premalignant, and malignant melanocytic lesions to determine possible associations with tumor progression and clinicopathological characteristics. In total, 184 tissue samples, including benign and dysplastic nevi, in-situ melanomas, superficial (Breslow's depth <1 mm), and deep (Breslow's depth >4 mm) invasive melanomas and lymph node metastases, were analyzed for macrophage content. Samples were stained immunohistochemically for CD68 and CD163, representing all TAMs and M2-macrophages, respectively. Macrophages were counted by hotspot analysis, and assessed semiquantitatively from the tumor cell nests and stromal component of malignant cases. CD68+ and CD163+ TAMs were more abundant in invasive melanomas compared with benign nevi. The proportion of TAMs in the tumor nests was higher in deep melanomas and lymph node metastases compared with superficially invasive melanomas. High amounts of CD68+ macrophages in tumor cell nests were associated with recurrence, whereas low CD163+ macrophage proportion in tumor stroma was associated with recurrence and in primary melanomas also with poor overall survival. TAMs seem to promote tumor progression in cutaneous melanoma. In particular, CD68+ TAMs and their abundance in tumor nests were associated with poor prognostic factors. However, the correlation of low stromal CD163+ TAM proportion with a poor prognosis indicates that the role of TAMs depends on their subtype and microanatomical localization.

Outcomes and Risk Factors in Patients with Multiple Primary Melanomas

The incidence and patient survival rates of melanoma have increased over the last several decades, with a growing population of patients who develop multiple primary melanomas (MPMs). To determine risk factors for developing MPMs and compare the survival of patients with MPMs to those with single primary melanomas, a prospective, multidisciplinary database of patients with melanoma at a single tertiary care institution was retrospectively reviewed. From 1985 to 2013, 6,963 patients with single primary melanomas and 305 patients with MPMs were identified. Mean follow-up was 8.3 ± 6.3 years for patients with single primary melanomas and 8.8 ± 5.9 years for patients with MPMs. Risk of developing multiple melanomas increased with age at diagnosis of first melanoma (hazard ratio [HR] = 1.20 for a 10-year increase in age, 95% confidence interval [CI] = 1.11-1.29, P < 0.001), male sex (HR = 1.44, 95% CI = 1.12-1.84, P = 0.005), and white race (HR = 3.07, 95% CI = 1.45-6.51). Patients with invasive MPMs had increased risk of melanoma-specific death both before (HR = 1.47, 95% CI = 1.0-2.2) and after adjusting for age, sex, site, race, family history of melanoma, personal history of other cancer, and Surveillance, Epidemiology, and End Results Program (SEER) stage (HR = 1.44, 95% CI = 0.95-2.2); however, this result did not reach statistical significance.

Stage IV melanoma of unknown primary: A population-based study in the United States from 1973 to 2014

BACKGROUND

Melanoma of unknown primary (MUP) is incompletely described on a population level.

OBJECTIVE

We sought to characterize stage IV MUP in a population-based cancer registry.

METHODS

We developed a novel search algorithm to identify cases of stage IV MUP in the Surveillance, Epidemiology, and End Results 18 registries from 1973 to 2014. Cases of stage IV melanoma of known primary (MKP) served as a comparison group. Age-standardized incidence rates, demographic characteristics, adjusted disease-specific survival, and Cox proportional hazard models were calculated for MUP and MKP.

RESULTS

A total of 322 stage IV MUP cases and 12,796 stage IV MKP cases were identified in Surveillance, Epidemiology, and End Results 18 registries from 1973 to 2014. The incidence of stage IV MUP is increasing, particularly for patients younger than 30 years of age. In multivariate analyses, age older than 50 and a lack of surgical treatment were negative prognostic factors for stage IV MUP. Relative survival, but not 5-year adjusted disease-specific survival, was higher for stage IV MUP than for MKP.

LIMITATIONS

Limitations include the retrospective study design and possible misclassification of MUP.

CONCLUSIONS

The incidence of stage IV MUP is increasing, and stage IV MUP shares similar prognostic factors with stage IV MKP, including age and surgical treatment.

Vitamin D deficiency is associated with a worse prognosis in metastatic melanoma

Vitamin D deficiency (≤20 ng/mL) is associated with an increased incidence and worse prognosis of various types of cancer including melanoma. A retrospective, single-center study of individuals diagnosed with melanoma from January 2007 through June 2013 who had a vitamin D (25(OH)D3) level measured within one year of diagnosis was performed to determine whether vitamin D deficiency and repletion are associated with melanoma outcome. A total of 409 individuals diagnosed with histopathology-confirmed melanoma who had an ever measured serum 25(OH)D3 level were identified. 252 individuals with a 25(OH)D3 level recorded within one year after diagnosis were included in the study and the individual and melanoma characteristics such as age, sex, Breslow thickness, ulceration, stage, mitotic rate, and LDH were obtained from the medical record. A worse melanoma prognosis was associated with vitamin D deficiency (P=0.012), higher stage (P<0.001), ulceration (P=0.001), and higher mitotic rate (P=0.001) (HR 1.93, 95% CI 1.15-3.22). In patients with stage IV metastatic melanoma, vitamin D deficiency was associated with significantly worse melanoma-specific mortality (adjusted HR 2.06, 95% CI 1.10-3.87). Patients with metastatic melanoma who were initially vitamin D deficient and subsequently had a decrease or ≤20 ng/mL increase in their 25(OH)D3 concentration had significantly worse outcomes (HR 4.68, 95% CI 1.05-20.88) compared to non-deficient patients who had a >20 ng/mL increase. Our results suggest that initial vitamin D deficiency and insufficient repletion is associated with a worse prognosis in patients with metastatic melanoma.

Cancer survival in adult patients in Spain. Results from nine population-based cancer registries

INTRODUCTION

With the aim of providing cancer control indicators, this work presents cancer survival in adult (≥15 years) patients in Spain diagnosed during the period 2000-2007 from Spanish cancer registries participating in the EUROCARE project.

METHODS

Cancer cases from nine Spanish population-based cancer registries were included and analysed as a whole. All primary malignant neoplasms diagnosed in adult patients were eligible for the analysis. Cancer patients were followed until 31 December 2008. For each type of cancer, 1-, 3- and 5-year observed and relative survival were estimated by sex, age and years from diagnosis. Furthermore, age-standardized 5-year relative survival for the period 2000-2007 has been compared with that of the period 1995-1999.

RESULTS

Skin melanoma (84.6 95% CI 83.0-86.2), prostate (84.6% 95% CI 83.6-85.6) and thyroid (84.2% CI 95% 82.0-86.6) cancers showed the highest 5-year relative survival, whereas the worst prognosis was observed in pancreatic (6% 95% CI 5.1-7.0) and oesophageal (9.4% 95% CI 7.9-11.1) cancers. Overall, survival is higher in women (58.0%) than in men (48.9%). The absolute difference in relative survival between 2000-2007 and 1995-1999 was positive for all cancers as a whole (+4.8% in men, +1.6% in women) and for most types of tumours. Survival increased significantly for chronic myeloid leukaemia, non-Hodgkin's lymphoma and rectum cancer in both sexes, and for acute lymphoid leukaemia, prostate, liver and colon cancers in men and Hodgkin's lymphoma and breast cancer in women. Survival patterns by age were similar in Europe and Spain. A decline in survival by age was observed in all tumours, being more pronounced for ovarian, corpus uteri, prostate and urinary bladder and less for head and neck and rectum cancers.

CONCLUSION

High variability and differences have been observed in survival among adults in Spain according to the type of cancer diagnosed, from above 84% to below 10%, reflecting high heterogeneity. The differences in prognosis by age, sex and period of diagnosis reveal opportunities for improving cancer care in Spain.

Authentication of M14 melanoma cell line proves misidentification of MDA-MB-435 breast cancer cell line

A variety of analytical approaches have indicated that melanoma cell line UCLA‐SO‐M14 (M14) and breast carcinoma cell line MDA‐MB‐435 originate from a common donor. This indicates that at some point in the past, one of these cell lines became misidentified, meaning that it ceased to correspond to the reported donor and instead became falsely identified (through cross‐contamination or other means) as a cell line from a different donor. Initial studies concluded that MDA‐MB‐435 was the misidentified cell line and M14 was the authentic cell line, although contradictory evidence has been published, resulting in further confusion. To address this question, we obtained early samples of the melanoma cell line (M14), a lymphoblastoid cell line from the same donor (ML14), and donor serum preserved at the originator's institution. M14 samples were cryopreserved in December 1975, before MDA‐MB‐435 cells were established in culture. Through a series of molecular characterizations, including short tandem repeat (STR) profiling and cytogenetic analysis, we demonstrated that later samples of M14 and MDA‐MB‐435 correspond to samples of M14 frozen in 1975, to the lymphoblastoid cell line ML14, and to the melanoma donor's STR profile, sex and blood type. This work demonstrates conclusively that M14 is the authentic cell line and MDA‐MB‐435 is misidentified. With clear provenance information and authentication testing of early samples, it is possible to resolve debates regarding the origins of problematic cell lines that are widely used in cancer research.

What's new?

A variety of analytical approaches have indicated that melanoma cell line M14 and breast carcinoma cell line MDA‐MB‐435 originate from a common donor, but there is ongoing debate regarding which is the misidentified cell line. Here, authentication testing of M14 from 1975 (prior to the establishment of MDA‐MB‐435), with comparison to donor serum and lymphoblastoid cell line ML14, shows that M14 is the authentic cell line and MDA‐MB‐435 is a misidentified derivative. With clear provenance information and authentication testing of early samples, debates regarding the origins of problematic cell lines that are widely used in cancer research can be resolved.

Evaluation of clinicopathological factors in PD-1 response: derivation and validation of a prediction scale for response to PD-1 monotherapy

Background:

Anti-PD-1 therapy has shown significant clinical activity in advanced melanoma. We developed and validated a clinical prediction scale for response to anti- PD-1 monotherapy.

Methods:

A total of 315 patients with advanced melanoma treated with pembrolizumab (2 or 10 mg kg⁻¹ Q2W or Q3W) or nivolumab (3 mg kg⁻¹ Q2W) at four cancer centres between 2011 to 2013 served as the setting for the present cohort study. Variables with significant association to response on a univariate analysis were entered into a forward stepwise logistic regression model and were given a score based on ORs to calculate a clinical prediction scale.

Results:

The developed clinical prediction scale included elevated LDH (1 point), age <65 years (1 point), female sex (1 point), history of ipilimumab treatment (2 points) and the presence of liver metastasis (2 points). The scale had an area under the receiver-operating curve (AUC) of 0.73 (95% CI 0.67, 0.80) in predicting response to therapy. The predictive performance of the score was maintained in the validation cohort (AUC 0.70 (95% CI 0.58, 0.81)) and the goodness-to-fit model demonstrated good calibration.

Conclusions:

Based on a large cohort of patients, we developed and validated a simple five-factor prediction scale for the clinical activity of PD-1 antibodies in advanced melanoma patients. This scale can be used to stratify patients participating in clinical trials.

Sex differences in the association of cutaneous melanoma incidence rates and geographic ultraviolet light exposure

BACKGROUND

Cutaneous melanoma (CM) incidence rates continue to increase, and the reasons are unknown. Previously, we reported a unique age-specific sex difference in melanoma that suggested additional causes other than solar ultraviolet (UV) radiation.

OBJECTIVE

This study attempted to understand whether and how UV radiation differentially impacts the CM incidence in men and women.

METHODS

CM data and daily UV index (UVI) from 31 cancer registries were collected for association analysis. A second dataset from 42 US states was used for validation.

RESULTS

There was no association between log-transformed female CM rates and levels of UVI, but there was a significant association between male rates and UVI and a significant association between overall rates and UVI. The 5-year age-specific rate-UVI association levels (represented by Pearson's coefficient ρ) increased with age in men, but age-specific ρ levels remained low and unchanged in women. The significant rate-UVI association in men and nonassociation in women was validated in a population of white residents of the United States.

LIMITATIONS

Confounders, including temperature and latitude, are difficult to separate from UVI.

CONCLUSIONS

Ambient UVI appears to be associated with melanoma incidence in males but not in females.

Polymorphisms in apoptosis-related genes in cutaneous melanoma prognosis: sex disparity

Cutaneous melanoma (CM) cells are resistant to apoptosis, and steroid hormones are involved in this process through regulation of TP53, MDM2, BAX, and BCL2 expression. We analyzed herein sex differences in outcomes of CM patients associated with TP53 c.215G>C, MDM2 c.309T>G, BAX c.-248G>A, and BCL2 c.-717C>A polymorphisms. DNA from 121 men and 116 women patients was analyzed by polymerase chain reaction and enzymatic digestion assays. At 60 months of follow-up, shorter progression-free survival (PFS) was seen in males with MDM2 GG + BCL2 AA (20.0 vs. 62.6%, P = 0.0008) genotype. Men carriers of the genotype had poor PFS (HR 3.78, 95% CI 1.30-11.0) than others. For women, shorter PFS was associated with TP53 GC or CC (61.4 vs. 80.8%, P = 0.01) and TP53 GC or CC + MDM2 TG or GG (59.1 vs. 85.4%, P = 0.01) genotypes at the same time. Women carriers of the genotypes had poor PFS (HR 2.46, 95% CI 1.19-5.09; HR 9.49, 95% CI 1.14-78.50) than others, respectively. Our data present, for the first time, preliminary evidence that inherited abnormalities on TP53, MDM2 and BCL2 genes, enrolled in apoptosis pathways, have a pivotal role in differences of outcomes in women and men with CM.

Trends in incidence and survival of cutaneous malignant melanoma in Estonia: a population-based study

BACKGROUND

Previous studies have shown an increase in the incidence of cutaneous melanoma (CM) in Estonia, but also poor survival in international comparisons, with a significant survival gap between the sexes. The aim of this study was to analyze the time trends in CM incidence and relative survival by age, TNM stage and anatomical subsite among men and women in Estonia.

MATERIALS AND METHODS

Data from the Estonian Cancer Registry were used to calculate age-standardized (World) and age-specific incidence of CM in 1995-2013, and five-year relative survival ratios (RSR) for cases diagnosed in 1995-2012 and followed through in 2014. Period hybrid analysis was used to calculate the most recent survival estimates for 2010-2014.

RESULTS

Between 1995 and 2013, the age-standardized incidence of CM increased significantly in Estonia among both sexes, at a rate of around 4% per year. Among women, the proportion of trunk melanomas increased from 26% in 1995-1999 to 39% in 2010-2012 and became the most common site. The proportion of stage I cases and T1 tumors increased considerably. Women had more favorable stage distribution and thinner tumors than men. The age-adjusted five-year RSR increased significantly, from 64% in 1995-1999 to 81% in 2010-2014. The latest age-adjusted RSRs were 76% among men and 84% among women. Survival gains were the largest in patients below 50 years, those with head and neck or trunk melanomas, and stage III cancer.

CONCLUSIONS

The proportion of stage I and T1 cases is lower in Estonia compared with the Scandinavian data and is likely a major contributor to the persisting overall survival deficit in Estonia. The apparent deficit in stage II survival also warrants further investigation. A public health program is necessary in Estonia to raise awareness of CM and to significantly increase early stage diagnosis.

Clinical Characteristics of Malignant Melanoma in Southwest China: A Single-Center Series of 82 Consecutive Cases and a Meta-Analysis of 958 Reported Cases

Purpose

The present study determined the clinical characteristics and prognostic factors in patients with malignant melanoma based on a series of 82 cases from January 2009 to December 2014 in Southwest Hospital and a meta-analysis (including 12 articles) involving 958 patients in China.

Materials and methods

The database elements included basic demographic data and prognosticators which were extracted from medical records. Statistical analyses of survival, and multivariate analyses of factors associated with survival were performed using the Kaplan—Meier method, and the Cox proportional hazard model, respectively. Literatures were identified through systematic searches in PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI) and Weipu database (VIP) database for the period from inception to December 2015. The meta-analysis was conducted using R 3.1.1 meta-analysis software

Results

In this series of 82 cases, the median age of the patients was 57.50 years. Melanoma was located in the foot in 79% of patients. Sixty-one patients (74.4%) were classified as stage II-III. Thirty-two patients (39.0%) had acral malignant melanoma, and 31 patients (37.8%) had nodular malignant melanoma. The clinical characteristics of melanoma were similar to those in areas outside southwest China (from results of the meta-analysis). The median survival time was 29.50 months. The 1-year, 3-year, and 5-year survival rates were 84.1%, 39.0% and 10.9%, respectively. COX regression following multi-factor analysis showed that ulcer, tumor boundary and lymph node metastasis were associated with prognosis.

Conclusions

The clinical characteristics of melanoma in Chinese were different from those in Caucasians. Ulcer, tumor margins, and lymph node metastasis were significantly associated with prognosis. Immune therapy may prolong the median survival time of patients with acral melanoma, nodular melanoma, or stage I-III disease, although these differences were not statistically significant.

A comprehensive genome-wide analysis of melanoma Breslow thickness identifies interaction between CDC42 and SCIN genetic variants

Breslow thickness (BT) is a major prognostic factor of cutaneous melanoma (CM), the most fatal skin cancer. The genetic component of BT has only been explored by candidate gene studies with inconsistent results. Our objective was to uncover the genetic factors underlying BT using an hypothesis-free genome-wide approach. Our analysis strategy integrated a genome-wide association study (GWAS) of single nucleotide polymorphisms (SNPs) for BT followed by pathway analysis of GWAS outcomes using the gene-set enrichment analysis (GSEA) method and epistasis analysis within BT-associated pathways. This strategy was applied to two large CM datasets with Hapmap3-imputed SNP data: the French MELARISK study for discovery (966 cases) and the MD Anderson Cancer Center study (1,546 cases) for replication. While no marginal effect of individual SNPs was revealed through GWAS, three pathways, defined by gene ontology (GO) categories were significantly enriched in genes associated with BT (false discovery rate ≤5% in both studies): hormone activity, cytokine activity and myeloid cell differentiation. Epistasis analysis, within each significant GO, identified a statistically significant interaction between CDC42 and SCIN SNPs (pmeta-int =2.2 × 10(-6) , which met the overall multiple-testing corrected threshold of 2.5 × 10(-6) ). These two SNPs (and proxies) are strongly associated with CDC42 and SCIN gene expression levels and map to regulatory elements in skin cells. This interaction has important biological relevance since CDC42 and SCIN proteins have opposite effects in actin cytoskeleton organization and dynamics, a key mechanism underlying melanoma cell migration and invasion.

Stress, catecholaminergic system and cancer

Stress as a modern civilization factor significantly affects our lives. While acute stress might have a positive effect on the organism, chronic stress is usually detrimental and might lead to serious health complications. It is known that stress induced by the physical environment (temperature-induced cold stress) can significantly impair the efficacy of cytotoxic chemotherapies and the anti-tumor immune response. On the other hand, epidemiological evidence has shown that patients taking drugs known as β-adrenergic antagonists ("β-blockers"), which are commonly prescribed to treat arrhythmia, hypertension, and anxiety, have significantly lower rates of several cancers. In this review, we summarize the current knowledge about catecholamines as important stress hormones in tumorigenesis and discuss the use of β-blockers as the potential therapeutic agents.