Cutaneous malignant melanoma in women. Phenotypic characteristics, sun exposure, and hormonal factors: a case-control study from Italy

A Narrative Review of the Role of Estrogen (Receptors) in Melanoma

In this narrative review, we attempt to provide an overview of the evidence regarding the role of estrogen (receptors) in cutaneous melanoma (CM). We reviewed 68 studies and 4 systematic reviews and meta-analyses published from 2002 up to and including 2022. The prevailing presence of estrogen receptor β (ERβ) instead of estrogen receptor α (ERα) in CM is notable, with ERβ potentially playing a protective role and being less frequently detected in progressive cases. While men with CM generally experience a less favorable prognosis, this distinction may become negligible with advancing age. The role of oral contraceptives (OC) and hormone replacement therapy (HRT) in CM remains controversial. However, recent studies tend to associate the use of these exogenous hormones with a heightened risk of CM, mostly only when using estrogen therapy and not in combination with progesterone. On the contrary, the majority of studies find no substantial influence of in vitro fertilization (IVF) treatment on CM risk. Reproductive factors, including younger age at first childbirth, higher parity, and shorter reproductive life, show conflicting evidence, with some studies suggesting a lower CM risk. We suggest an important role for estrogens in CM. More research is needed, but the integration of estrogens and targeting the estrogen receptors in melanoma therapy holds promise for future developments in the field.

The effect of menopausal hormone therapy on the risk of melanoma and keratinocyte skin cancer: A systematic review and meta-analysis of observational studies

BACKGROUND

Whether menopausal hormone therapy (MHT) increases the risk of skin cancer is controversial.

AIM

To systematically review and meta-analyze evidence regarding the association of MHT with the risk of melanoma and keratinocyte cancer (KC).

MATERIAL AND METHODS

A comprehensive literature search was conducted of the PubMed, Scopus and Cochrane databases, through to 30 October 2021. Skin neoplasms were divided into melanoma and KC. In the latter category, both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) were considered. The results are presented as hazard ratios (HR) with 95 % confidence intervals (CI). The I² index was used to assess heterogeneity. Subgroup analysis and sensitivity analysis were also conducted in order to explore potential differences among studies.

RESULTS

Twenty-seven studies were included in the qualitative and 23 in the quantitative analysis, with a total of 2,612,712 menopausal women (25,126 with skin cancer; 20,150 with melanoma). MHT was associated with an increased risk of melanoma (HR 1.11; 95 % CI 1.05-1.19; I² 45%). With regard to MHT type, both estrogen monotherapy (HR 1.22, 95 % CI 1.16-1.29; I² 0%) and estrogen in combination with progestogen (HR 1.11, 95 % CI 1.05-1.18, I² 26%) significantly increased that risk. Regarding melanoma subtype, superficial spreading melanoma (SSM) and lentigo maligna melanoma (LMM) were the only histologic subtypes associated with MHT use. MHT was also associated with an increased risk of KC (HR 1.17, 95 % CI 1.04-1.31, I² 83%), specifically BCC (HR 1.22, 95 % CI 1.12-1.32; I² 29%). Longer duration (>5 years) of MHT, current use and estrogen monotherapy were associated with an increased KC risk compared with no use.

CONCLUSION

The use of MHT by postmenopausal women was associated with an increased risk of melanoma and KC. This risk was higher for current MHT users and those treated for over 5 years.

Exogenous Hormone Factors in Relation to the Risk of Malignant Melanoma in Women: A Systematic Review and Meta-Analysis

The influence of exogenous female hormones on the risk of developing malignant melanoma in women remains controversial. The aim of our review and meta-analysis is to summarize the evidence and derive a more accurate estimation of the association between oral contraceptives (OCs) or menopausal hormone therapy (MHT) and the risk of developing malignant melanoma in women. PubMed, Web of Science, and Scopus database were searched for studies published up until October 2021. The PRISMA statement and MOOSE guidelines were followed. Studies were pooled using a random effects model. Heterogeneity was explored with the chi-square-based Cochran’s Q statistic and the I2 statistic. Publication bias was assessed with Begg’s test and Egger’s test. Forty-six studies met the eligibility criteria. The pooled analysis (26 studies) on OC use and the risk of developing cutaneous malignant melanoma (CMM) showed no significant association, but demonstrated significant association for cohort studies (OR 1.08, 95% CI 1.01–1.16; I2 = 0.00%, p = 0.544). The pooled analysis (16 studies) showed a significantly increased risk of CMM in association with MHT (OR 1.15, 95% CI 1.08–1.23; I2 = 25.32%, p = 0.169). Stratifying the results by study design showed that a significant increased risk of CMM was associated with MHT in the cohort studies (OR 1.12; 95% CI 1.04–1.19; I2 = 0%, p = 0.467). No significant publication bias could be detected. Further studies are needed to investigate the potential association with formulation, duration of use, and dosage of use, and to better understand the role of possible confounders.

ABO blood group and skin cancers

Beside the role of ABO group in immunohaematology, there is accumulating evidence that the ABO blood group also plays a key role in various human disorders. The interest in blood groups and their association with disease stems from the awareness that blood group antigens are incredibly important components in the process of cell maturation and control. Studies have indicated a link between cancer and the ABO blood group. The appearance or disappearance of blood type antigens is now considered a hallmark of malignancy in many common cancers. Several tumour markers are in fact known blood group antigens. The aim of this review is to describe the history and possible functions of the ABO group and then summarize the association between blood groups and skin cancers.

Effects of Exogenous Hormones and Reproductive Factors on Female Melanoma: A Meta-Analysis

Epidemiological findings on the effects of hormones on melanoma risk have been inconsistent. We therefore conducted a meta-analysis to examine the relationship between exogenous hormonal and reproductive factors and the risk of melanoma in women. We performed a search of PubMed, Web of Science, and the China National Knowledge Infrastructure (CNKI) database through April 2020 for relevant studies. Based on heterogeneity, we performed the meta-analysis of the risk estimates using either fixed effect or random effect models. We identified 38 studies that met the analytical criteria, involving 3,571,910 participants. The results showed that long-term use of oral contraceptives (OC) may increase the risk of melanoma in women (≥5 years [pooled RR=1.18; 95% CI: 1.07-1.31; I²=0%] and ≥10 years [pooled RR=1.25; 95% CI: 1.06-1.48; I²=0%]). Women who first used OC 15-19 years previously were more likely to develop melanoma (pooled RR=1.52; 95% CI: 1.03-2.24; I²=0%), while the years since the last use and the age at first use were not associated with the development of melanoma in women. Hormone replacement therapy (HRT) increased the incidence of melanoma in women (pooled RR=1.12, 95% CI: 1.02-1.24; I²=50%) and was especially associated with an increased risk of superficial spreading melanoma (SSM) (pooled RR=1.26; 95% CI: 1.17-1.37; I²=0%), and estrogen and estradiol may be the main active agents that contribute to the increased risk of melanoma, but these results may be due to a combination of sun exposure factors. With regard to reproductive factors, decreased parity and being aged ≥20 years at first birth may be associated with an increased risk of melanoma in females, while menopausal status and age at menarche are not associated with the incidence of melanoma in females. Further large-scale prospective studies are necessary to reveal new pathophysiological mechanisms and new therapeutic targets for cutaneous melanoma.

Postmenopausal exogenous hormone therapy and Melanoma risk in women: A systematic review and time-response meta-analysis

A favourable option to management symptoms during menopausal transition is menopausal hormone therapy (MHT) but relation among MHT and risk of melanoma is controversial. This study aims to identify, analyse and present the evidence surrounding post-menopausal exogenous hormone therapy and the risk for melanoma in women. A systematic searches of database was conducted in PubMed/MEDLINE, Scopus, and Cochrane without time, region, and language restrictions from inception to April 2020. The DerSimonian and Laird random-effects model was used to estimate combined risk ratio (RR) and 95% confidence intervals (CI). Subgroup analysis and time-response analysis was conducted based on the formulation of used hormone and length of hormone therapy. Combined results from fourteen studies that containing 19 arms with 1,164,077 participants which 4273 of them had melanoma cancer showed increase risk of melanoma in the hormone-treated versus control group 1.14 (95% CI 1.05-1.24, I2: 21%). The stronger and significant relationship between MHT and risk of melanoma was in participants who used oestrogen formulation (RR 1.32, 95% CI 1.17-1.49, I2 = 0%). Moreover, a significant non-linear time-response relation between MHT and melanoma was also in initial three years of MHT (Coef1 = 0.2423, p1 < 0.01). This study reveals a significant direct relationship between the MHT and risk of melanoma in postmenopausal women.

Nicotinamide N-methyltransferase: potential involvement in cutaneous malignant melanoma

Nicotinamide N-methyltransferase (NNMT) is an enzyme that catalyzes the N-methylation of nicotinamide and pyridine compounds, participating in xenobiotic and drug metabolism. Data on literature have evidenced a possible role of NNMT in many solid cancers, but no data are currently available in cutaneous melanoma. Recent important advances have been achieved in the treatment of advanced melanoma with targeted therapy and immunotherapy. However, the identification of biomarkers that can be used for the detection of early stage disease as well as for monitoring the therapeutic response during treatment is of utmost importance. The aim of this study was to study the possible role of NNMT in melanoma. In the present study, we carried out immunohistochemical analyses to evaluate the expression of the enzyme NNMT in 34 melanomas and 34 nevi. Moreover, we explored the relationship between NNMT levels and the prognostic parameters of patients with melanoma. The results obtained showed significantly (P<0.0001) higher NNMT expression in melanoma compared with that detected in nevi. In addition, a significant (P<0.05) inverse relationship was found between enzyme levels and Breslow thickness, Clark level, the presence/number of mitoses, and ulceration. Taken together, these data seem to suggest that NNMT could represent a molecular biomarker for melanoma, thus highlighting its potential for both diagnosis and prognosis of this neoplasm.

Childhood Body Size and the Risk of Malignant Melanoma in Adulthood

Malignant melanoma (MM) is the most aggressive form of skin cancer. Adult anthropometry influences MM development; however, associations between childhood body size and future melanomagenesis are largely unknown. We investigated whether height, body mass index (BMI; weight (kg)/height (m)²), and body surface area (BSA) at ages 7–13 years and birth weight are associated with adult MM. Data from the Copenhagen School Health Records Register, containing annual height and weight measurements of 372,636 Danish children born in 1930–1989, were linked with the Danish Cancer Registry. Cox regression analyses were performed. During follow-up, 2,329 MM cases occurred. Height at ages 7–13 years was significantly associated with MM, even after BMI and BSA adjustments. No significant BMI-MM or BSA-MM associations were detected when adjusting for height. Children who were persistently tall at both age 7 years and age 13 years had a significantly increased MM risk compared with children who grew taller between those ages. Birth weight was positively associated with MM. We conclude that associations between body size and MM originate early in life and are driven largely by height and birth weight, without any comparable influence of BMI or BSA. Melanoma transformation is unlikely to be due to height per se; however, height-regulating processes in childhood present new areas for mechanistic explorations of this disease.

Genetics and epigenetics of melanoma

Cancer affects multiple organs in the body Malignant melanoma involves the invasion of skin and occasionally mucosal membrane or eye choroidal tissues. The incidence of cutaneous malignant melanoma is on the increase worldwide and is a major concern in current research. The increase is associated with UV irradiation-induced genetic aberrations that stimulate skin melanocytes to develop unlimited growth. This eventually leads to cell immortality, which in turn causes metastases. The present review examines the genetics and epigenetics of this pathological state together with recent perspectives of the therapeutic management of disease.

Menopausal hormone therapy in cancer survivors: A narrative review of the literature

Decision making regarding the use of menopausal hormone therapy (MHT) for the treatment of bothersome menopausal symptoms in a cancer survivor can be complex, and includes assessment of its impact on disease-free or overall survival. Estrogen receptors are present in several cancer types, but this does not always result in estrogen-mediated tumor proliferation and adverse cancer-related outcomes. Estrogen may even be protective against certain cancers. Menopausal hormone therapy is associated with an increased risk of recurrence and mortality after diagnosis of some cancer types, but not others. We provide a narrative review of the medical literature regarding the risk of cancer recurrence and associated mortality with initiation of MHT after the diagnosis of breast, gynecologic, lung, colorectal, hematologic cancers, and melanoma. Menopausal hormone therapy may be considered for management of bothersome menopausal symptoms in women with some cancer types (e.g., colorectal and hematologic cancer, localized melanoma, and most cervical, vulvar and vaginal cancers), while nonhormonal treatment options may be preferred for others (e.g., breast cancer). In women with other cancer types, recommendations are less straightforward, and the use of MHT must be individualized.

Current Data on Risk Factor Estimates Does Not Explain the Difference in Rates of Melanoma between Hispanics and Non-Hispanic Whites

United States Hispanics have seven times lower melanoma incidence rates than non-Hispanic whites (NHW). It is unclear whether this difference can be explained solely by phenotypic risk factors, like darker skin, or whether modifiable risk factors, like sun exposure, also play a role. The purpose of this paper is to summarize what is currently known about melanoma risk factors among Hispanics and NHWs, and whether or not those differences could explain the difference in melanoma incidence. Through literature review, relative risks and prevalence of melanoma risk factors in Hispanics and NHWs were identified and used to calculate the expected rate in Hispanics and rate ratio compared to NHWs. We found that melanoma risk factors either have similar frequency in Hispanics and NHWs (e.g., many large nevi) or are less frequent in Hispanics but do not explain a high proportion of disease variation (e.g., red hair). Considering current knowledge of risk factor prevalence, we found that melanoma incidence rates in the two groups should actually be similar. Sun exposure behavior among Hispanics may contribute to the explanation for the 7-fold difference in melanoma rates. Currently, limited data exist on sun exposure behavior among Hispanics, but possibilities for improving primary prevention by further studying these practices are substantial.

Genome-wide meta-analysis identifies five new susceptibility loci for cutaneous malignant melanoma

Thirteen common susceptibility loci have been reproducibly associated with cutaneous malignant melanoma (CMM). We report the results of an international 2-stage meta-analysis of CMM genome-wide association studies (GWAS). This meta-analysis combines 11 GWAS (5 previously unpublished) and a further three stage 2 data sets, totaling 15,990 CMM cases and 26,409 controls. Five loci not previously associated with CMM risk reached genome-wide significance (P < 5 × 10(-8)), as did 2 previously reported but unreplicated loci and all 13 established loci. Newly associated SNPs fall within putative melanocyte regulatory elements, and bioinformatic and expression quantitative trait locus (eQTL) data highlight candidate genes in the associated regions, including one involved in telomere biology.

Effects of fertility drugs on cancers other than breast and gynecologic malignancies

OBJECTIVE

To examine the relationship of ovulation-stimulating drugs to risk of cancers other than breast and gynecologic malignancies.

DESIGN

Retrospective cohort study, with additional follow-up since initial report.

SETTING

Reproductive endocrinology practices.

PATIENT(S)

Among a cohort of 12,193 women evaluated for infertility between 1965 and 1988, a total of 9,892 women (81.1% of the eligible population) were followed through 2010, via passive and active (questionnaire) approaches.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Hazard ratios (HRs) and 95% confidence intervals (CIs) for various fertility treatment parameters for select cancers.

RESULT(S)

During 30.0 median years of follow-up (285,332 person-years), 91 colorectal cancers, 84 lung cancers, 55 thyroid cancers, and 70 melanomas were diagnosed among study subjects. Clomiphene citrate (CC), used by 38.1% of patients, was not associated with colorectal or lung cancer risks, but was related significantly to melanoma (HR = 1.95; 95% CI: 1.18-3.22), and non-significantly to thyroid cancer risks (HR = 1.57; 95% CI: 0.89-2.75). The highest melanoma risks were seen among those with the lowest drug exposure levels, but thyroid cancer risk was greatest among the heavily exposed patients (HR = 1.96; 95% CI: 0.92-4.17 for those receiving >2,250 mg). Clomiphene citrate-associated risks for thyroid cancer were somewhat higher among nulligravid, compared with gravid, women, but did not differ according to distinct causes of infertility. Gonadotropins, used by only 9.7% of subjects, were not related to risk of any of the assessed cancers.

CONCLUSION(S)

Our results provide support for continued monitoring of both melanoma and thyroid cancer risk among patients receiving fertility drugs.

Emerging trends in the epidemiology of melanoma

Cutaneous melanoma (CM) is one of the most rapidly growing cancers worldwide, with a consistent increase in incidence among white populations over the past four decades. Despite the early detection of primarily thin melanomas and the improved survival rates observed in several countries, the rate of thick melanomas has remained constant or continues to increase, especially in the older age group. Current considerations in the epidemiology of melanoma focus on the observed survival benefit of females vs. males, the contributing role of indoor tanning in melanoma risk and the diverse effect of sun exposure in the development of different types of melanoma with respect to their clinical and mutational profile. Certain well-known risk factors, such as skin, hair and eye pigmentation and melanocytic naevi have been validated in large-scale association studies, while additional lifestyle factors and iatrogenic exposures, such as immunosuppressive agents and nonsteroidal anti-inflammatory drugs are being investigated. In addition, genome-wide association studies have revealed genetic loci that underlie the genetic susceptibility of melanoma, some of which are related to known risk factors. Recently, an interesting association of melanoma with Parkinson disease has been noted, with a higher than expected frequency of melanoma in patients with Parkinson disease and vice versa. This review article provides an update in the epidemiology of cutaneous melanoma and discusses recent developments in the field.

A variant in FTO shows association with melanoma risk not due to BMI

We report the results of an association study of melanoma that is based on the genome-wide imputation of the genotypes of 1,353 cases and 3,566 controls of European origin conducted by the GenoMEL consortium. This revealed an association between several SNPs in intron 8 of the FTO gene, including rs16953002, which replicated using 12,313 cases and 55,667 controls of European ancestry from Europe, the USA and Australia (combined P = 3.6 × 10(-12), per-allele odds ratio for allele A = 1.16). In addition to identifying a new melanoma-susceptibility locus, this is to our knowledge the first study to identify and replicate an association with SNPs in FTO not related to body mass index (BMI). These SNPs are not in intron 1 (the BMI-related region) and exhibit no association with BMI. This suggests FTO's function may be broader than the existing paradigm that FTO variants influence multiple traits only through their associations with BMI and obesity.

Risk factors for malignant melanoma in white and non-white/non-African American populations: the multiethnic cohort

It is unknown whether the established risk factors for malignant melanoma in whites influence malignant melanoma risk in non-whites. We examined the risk factors for melanoma among 39,325 whites and 101,229 non-whites/multiracials [Japanese American (47.5%), Latino American (34.8%), Native Hawaiian (2.1%), and multiracial (15.6%), excluding African Americans] in the Multiethnic Cohort study. With an average follow-up of 12.7 years, 581 invasive malignant melanoma (IMM) and 412 melanoma in situ (MIS) cases were identified, of which 107 IMM and 74 MIS were among non-whites/multiracials. The relative risks (RR) and 95% confidence intervals (CI) were estimated by Cox proportional hazards models using days from cohort entry as the underlying time variable. Among non-white/multiracial males, location of IMM tumors differed from those of white males (P < 0.001); and non-white/multiracial females were more likely to be diagnosed with later stage of disease (P < 0.001). After adjusting for potential confounders, age at cohort entry, male sex, higher education, and sunburn susceptibility phenotypes were associated with an increased risk of IMM in non-whites/multiracials (P < 0.05). The risk estimates for age at cohort entry and lighter hair and eye color were greater in non-whites/multiracials than in whites (P(heterogeneity) = 0.062, 0.016, and 0.005, respectively). For MIS risk, RRs between whites and non-whites/multiracials also differed for study location and education (P(heterogeneity) ≤ 0.015). In conclusion, similar to whites, age at cohort entry, male sex, and susceptibility to sunburn phenotypes may be predictive of malignant melanoma risk in non-white populations excluding African Americans.

A novel recurrent mutation in MITF predisposes to familial and sporadic melanoma

Whole-genome sequencing identifies a novel germline variant in the oncogene MITF, which is associated with the development of melanoma.

Two papers in this issue of Nature demonstrate that missense substitutions in the gene encoding for microphthalmia-associated transcription factor (MITF) are associated with susceptibility to melanoma and renal cell carcinoma. Functional analysis shows that the variant has impaired sumoylation that leads to differential regulation of several MITF targets, and promotes tumour cell clonogenicity, migration and invasion.

So far, two genes associated with familial melanoma have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases¹, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds². Here we report the whole-genome sequencing of probands from several melanoma families, which we performed in order to identify other genes associated with familial melanoma. We identify one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log of odds (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case–control sample. Likewise, it was similarly associated in an independent case–control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.

Genome-wide association study identifies three new melanoma susceptibility loci

We report a genome-wide association study for melanoma that was conducted by the GenoMEL Consortium. Our discovery phase included 2,981 individuals with melanoma and 1,982 study-specific control individuals of European ancestry, as well as an additional 6,426 control subjects from French or British populations, all of whom were genotyped for 317,000 or 610,000 single-nucleotide polymorphisms (SNPs). Our analysis replicated previously known melanoma susceptibility loci. Seven new regions with at least one SNP with P < 10(-5) and further local imputed or genotyped support were selected for replication using two other genome-wide studies (from Australia and Texas, USA). Additional replication came from case-control series from the UK and The Netherlands. Variants at three of the seven loci replicated at P < 10(-3): an SNP in ATM (rs1801516, overall P = 3.4 × 10(-9)), an SNP in MX2 (rs45430, P = 2.9 × 10(-9)) and an SNP adjacent to CASP8 (rs13016963, P = 8.6 × 10(-10)). A fourth locus near CCND1 remains of potential interest, showing suggestive but inconclusive evidence of replication (rs1485993, overall P = 4.6 × 10(-7) under a fixed-effects model and P = 1.2 × 10(-3) under a random-effects model). These newly associated variants showed no association with nevus or pigmentation phenotypes in a large British case-control series.

Estrogens, estrogen receptors and melanoma

The skin is the largest nonreproductive target tissue on which estrogen plays many beneficial and protective roles. Although neither exogenous hormones nor pregnancy represent significant risk factors for melanoma, epidemiological data suggest a higher survival rate in women with metastatic disease versus men and in premenopausal versus postmenopausal patients. Despite the fact that hyperestrogenic signaling has long been implicated in the initiation and progression of several tumors, the role of estrogens in malignant melanoma is still unclear. The cellular effects of estrogens are mediated by two subtypes of estrogen receptors (ERs). Estrogen receptor β (ERβ), the predominant ER in the skin, antagonizes the proliferative action mediated by estrogen receptor α. According to recent immunohistochemical studies, ERβ protein expression decreases progressively with increased Breslow thickness and results in more invasive melanomas; thus, ERβ immunophenotype may distinguish melanomas linked to poor prognosis from those with a favorable course and lead to melanoma unresponsiveness to both estrogen and anti-estrogen treatment. Therefore, if future large-scale immunohistochemical and molecular studies point towards ERβ as an important factor in malignant melanoma progression, they will open up novel and targeted prognostic and therapeutic perspectives.

Menopausal hormone therapy and risks of melanoma and nonmelanoma skin cancers: women's health initiative randomized trials

BACKGROUND

Case-control studies have reported that exogenous estrogen use is associated with increased risk of skin cancer. The effects of menopausal hormone therapy on incidence of nonmelanoma skin cancer and melanoma were evaluated in post hoc analyses of the Women's Health Initiative randomized placebo-controlled hormone therapy trials of combined estrogen plus progestin (E + P) and estrogen only (E-alone).

METHODS

Postmenopausal women aged 50-79 years were randomly assigned to conjugated equine estrogen (0.625 mg/d) plus medroxyprogesterone acetate (2.5 mg/d) or placebo in the E + P trial if they had an intact uterus (N = 16,608) or to conjugated equine estrogen alone or placebo in the E-alone trial if they had a hysterectomy (N = 10,739); the mean follow-up was 5.6 and 7.1 years, respectively. Incident nonmelanoma skin cancers (n = 980 [E + P trial]; n = 820 [E-alone trial]) and melanomas (n = 57 [E + P trial]; n =38 [E-alone trial]) were ascertained by self-report. Incident cases of cutaneous malignant melanoma were confirmed by physician review of medical records. Incidences of nonmelanoma skin cancer and melanoma were compared between the two randomization groups within each trial using hazard ratios (HRs), with corresponding 95% confidence intervals (CIs) and Wald statistic P values from Cox proportional hazards models. All statistical tests were two-sided.

RESULTS

Rates of incident nonmelanoma skin cancer and melanoma were similar between the active hormone (combined analysis of E + P and E-alone) and placebo groups (nonmelanoma skin cancer: HR = 0.98, 95% CI = 0.89 to 1.07; melanoma: HR = 0.92, 95% CI = 0.61 to 1.37). Results were similar for the E + P and E-alone trials when analyzed individually.

CONCLUSIONS

Menopausal hormone therapy did not affect overall incidence of nonmelanoma skin cancer or melanoma. These findings do not support a role of menopausal estrogen, with or without progestin, in the development of skin cancer in postmenopausal women.

Hormonal and reproductive factors in relation to melanoma in women: current review and meta-analysis

A number of studies have focused on possible relationships between characteristics of female endocrine status and melanoma (CM) risk; however, the link between melanoma, oral contraceptive (OC) and hormonal replacement therapy (HRT) use, and reproductive factors remains controversial. A comprehensive, systematic bibliographic search of the medical literature was conducted to identify relevant studies. Random effects models were used to summarise results. Subgroup, meta-regression and sensitivity analyses have been carried out to explore sources of between-study variation and bias. We included thirty-six observational studies published in the last 30 years. Summarising a total of 5626 melanoma cases, we did not find any significant melanoma risk associated with OC and HRT use. Several reproductive factors were also investigated, summarising data on 16787 melanoma cases. We found a significantly increased melanoma risk for late age at first birth, and women with more than one child may be at a lower risk for melanoma; however, socio-economic confounders were found to play a significant role in explaining this association. This study confirmed no increased risk of CM with the use of oral contraceptives and hormone replacement therapy: exogenous female hormones do not contribute to an increased risk of CM. In contrast, significant associations of CM with parity and age at first pregnancy were observed in this meta-analysis finds and warrant further research.

Cutaneous melanoma and endogenous hormonal factors: a large French prospective study

To assess the role of endogenous hormonal factors on melanoma, the authors conducted a prospective analysis of 91,972 French women, aged 40-65 years at inclusion into the Etude Epidémiologique auprès de femmes de l'Education Nationale (E3N) cohort. Between 1990 and 2005, 460 melanoma cases were ascertained. Relative risks and 95% confidence intervals were computed by using Cox proportional hazards regression models. Risks of melanoma were reduced in women with ≥ 15 years at menarche (relative risk (RR) = 0.67, 95% confidence interval (CI): 0.46, 0.97, compared with 13-14 years), irregular menstrual cycles (RR = 0.52, 95% CI: 0.31, 0.89, compared with regular cycles of 25-31 days), <48 years at natural menopause (RR = 0.70, 95% CI: 0.48, 1.02, compared with 48-51 years), and shorter ovulatory life (RR = 0.51, 95% CI: 0.28, 0.91, for <33 years compared with ≥ 39 years). Modest inverse associations were observed with parity, as well as number of pregnancies and miscarriages. There was no evidence of an association between melanoma risk and age at first birth or pregnancy, age at last birth, time since last birth, breastfeeding duration, age at menstruation regularity, or menopausal status. Results did not significantly differ according to ambient ultraviolet radiation dose and melanoma site or subtype. These findings from a large prospective cohort may suggest a reduced melanoma risk associated with decreased exposure to ovarian hormones.

[Melanocytic nevi, melanoma, and pregnancy]

Malignant melanoma is among the malignant tumors whose incidence has risen markedly in recent decades. For many years the medical community debated the potential adverse effects of female hormones (whether of exogenous or pregnancy-related endogenous origin), on melanocytic nevi and malignant melanoma. Given that women have been delaying pregnancy until their thirties or forties and that the incidence of malignant melanoma increases in those decades, the likelihood of this tumor developing during pregnancy has increased. Recent clinical and experimental evidence has suggested that pregnancy does not affect prognosis in malignant melanoma and that it does not seem to lead to significant changes in nevi. This review examines the relationship between malignant melanoma and hormonal and reproductive factors. Evidence was located by MEDLINE search (in PubMed and Ovid) for articles in English and Spanish for the period from 1966 to March 2010; additional sources were found through the reference lists of the identified articles.

ABO blood group and incidence of skin cancer

Background

Previous studies have examined the association between ABO blood group and the risk of some malignancies. However, no prospective cohort study to date has examined the association between ABO blood group and the risk of skin cancer.

Methodology/Principal Findings

Using two large cohorts in the US, we examined ABO blood type and incidence of skin cancer, including melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC). We followed up study participants (70,650 female nurses and 24,820 male health professionals) on their diagnosis of incident skin cancer from cohort baseline (1976 in women and 1986 in men) until 2006. Study participants reported their blood type in 1996 in both cohorts. During the follow-up, 685 participants developed melanoma, 1,533 developed SCC and 19,860 developed BCC. We used Cox proportional hazards models to calculate the hazard ratios (HR) and 95% confidence intervals (CI) of each type of skin cancer. We observed that non-O blood group (A, AB, and B combined) was significantly associated with a decreased risk of non-melanoma skin cancer overall. Compared to participants with blood group O, participants with non-O blood group had a 14% decreased risk of developing SCC (multivariable HR: 0.86; 95% CI: 0.78, 0.95) and a 4% decreased risk of developing BCC (multivariable HR: 0.96; 95% CI: 0.93, 0.99). The decreased risk of melanoma for non-O blood group was not statistically significant (multivariable HR: 0.91; 95% CI: 0.78, 1.05).

Conclusion/Significance

In two large independent populations, non-O blood group was associated with a decreased risk of skin cancer. The association was statistically significant for non-melanoma skin cancer. Additional studies are needed to confirm these associations and to define the mechanisms by which ABO blood type or closely linked genetic variants may influence skin cancer risk.

Occupational physical activity and risk of malignant melanoma: the Western Canada Melanoma Study

The relationship between physical activity and cutaneous malignant melanoma has not been fully investigated; in particular, many previous studies have not controlled for sunlight exposure, which is an important environmental risk factor for melanoma. The aim of this study was to examine the relationship between occupational physical activity and melanoma risk. The data were collected for a population-based case-control study that consisted of 595 melanoma patients diagnosed between 1979 and 1981. Five hundred and ninety-five controls matched on sex, age and area of residence were selected from provincial government health insurance rolls. Lifetime job histories, sun exposure and other host factors were obtained from personal interviews with each individual. Logistic regression analysis was used to examine the relationship between melanoma risk and occupational activity levels, measured as total metabolic equivalent hours, with adjustment for occupational sun exposure, recreational sun exposure and host factors. Risk estimates were elevated above one for each occupational activity quintile compared with those with sedentary jobs. However, the pattern of risk ratios was irregular and statistical significance was reached only by the highest quintile (odds ratio: 1.59, 95% confidence interval: 1.02-2.47) and the second lowest quintile (odds ratio: 1.62, 95% confidence interval: 1.10-2.39). Our data showed an elevated risk for cutaneous malignant melanoma among those with higher levels of physical activity, although no clear dose-response relationship was observed. Further studies examining lifetime physical activity histories and sunlight exposure are required to explicate these findings.

Genome-wide association study identifies three loci associated with melanoma risk

We report a genome-wide association study of melanoma conducted by the GenoMEL consortium based on 317K tagging SNPs for 1,650 selected cases and 4,336 controls, with replication in an additional two cohorts (1,149 selected cases and 964 controls from GenoMEL, and a population-based case-control study in Leeds of 1,163 cases and 903 controls). The genome-wide screen identified five loci with genotyped or imputed SNPs reaching P < 5 x 10(-7). Three of these loci were replicated: 16q24 encompassing MC1R (combined P = 2.54 x 10(-27) for rs258322), 11q14-q21 encompassing TYR (P = 2.41 x 10(-14) for rs1393350) and 9p21 adjacent to MTAP and flanking CDKN2A (P = 4.03 x 10(-7) for rs7023329). MC1R and TYR are associated with pigmentation, freckling and cutaneous sun sensitivity, well-recognized melanoma risk factors. Common variants within the 9p21 locus have not previously been associated with melanoma. Despite wide variation in allele frequency, these genetic variants show notable homogeneity of effect across populations of European ancestry living at different latitudes and show independent association to disease risk.

Sex disparities in cancer incidence by period and age

BACKGROUND

Cancer epidemiology articles often point out that cancer rates tend to be higher among males than females yet rarely is this theme the subject of investigation.

METHODS

We used the Surveillance, Epidemiology and End Results program data to compute age-adjusted (2000 U.S. standard population) sex-specific incidence rates and male-to-female incidence rate ratios (IRR) for specific cancer sites and histologies for the period 1975 to 2004.

RESULTS

The 10 cancers with the largest male-to-female IRR were Kaposi sarcoma (28.73), lip (7.16), larynx (5.17), mesothelioma (4.88), hypopharynx (4.13), urinary bladder (3.92), esophagus (3.49), tonsil (3.07), oropharynx (3.06), and other urinary organs (2.92). Only 5 cancers had a higher incidence in females compared with males: breast (0.01), peritoneum, omentum, and mesentery (0.18), thyroid (0.39), gallbladder (0.57), and anus, anal canal, and anorectum (0.81). Between 1975 and 2004, the largest consistent increases in male-to-female IRR were for cancers of the tonsil, oropharynx, skin excluding basal and squamous, and esophagus, whereas the largest consistent decreases in IRR were for cancers of the lip and lung and bronchus. Male-to-female IRRs varied considerably by age, the largest increases of which were for ages 40 to 59 years for tonsil cancer and hepatocellular carcinoma. The largest decreases in male-to-female IRR by age, meanwhile, were for ages 30 to 49 years for thyroid cancer, ages >70 years for esophageal squamous cell carcinoma, and ages >30 years for lung and bronchus cancer.

CONCLUSION

These observations emphasize the importance of sex in cancer etiopathogenesis and may suggest novel avenues of investigation.

Cancer risk after exposure to treatments for ovulation induction

Uncertainty continues as to whether treatments for ovulation induction are associated with increased risk of cancer. The authors conducted a long-term population-based historical cohort study of parous women. A total of 15,030 women in the Jerusalem Perinatal Study who gave birth in 1974-1976 participated in a postpartum survey. Cancer incidence through 2004 was analyzed using Cox's proportional hazards models, controlling for age and other covariates. Women who used drugs to induce ovulation (n = 567) had increased risks of cancer at any site (multivariate hazard ratio (HR) = 1.36, 95% confidence interval (CI): 1.06, 1.74). An increased risk of uterine cancer was found among women treated with ovulation-inducing agents (HR = 3.39, 95% CI: 1.28, 8.97), specifically clomiphene (HR = 4.56, 95% CI: 1.56, 13.34). No association was noted between use of ovulation-inducing agents and ovarian cancer (age-adjusted HR = 0.61, 95% CI: 0.08, 4.42). Ovulation induction was associated with a borderline-significant increased risk of breast cancer (multivariate HR = 1.42, 95% CI: 0.99, 2.05). Increased risks were also observed for malignant melanoma and non-Hodgkin lymphoma. These associations appeared stronger among women who waited more than 1 year to conceive. Additional follow-up studies assessing these associations by drug type, dosage, and duration are needed.

Cutaneous melanoma and obesity in the Agricultural Health Study

PURPOSE

To describe the risk of cutaneous melanoma in the Agricultural Health Study (AHS), a cohort of pesticide applicators and their spouses, according to baseline characteristics related to obesity along with sun exposure and sun sensitivity.

METHODS

The AHS cohort was enrolled in Iowa and North Carolina during 1993-1997 and followed up through 2003 for cancer incidence. We identified 315 cases of cutaneous melanoma, which reduced to 168 incident cases among subjects reporting height, weight, sun sensitivity, and sun exposure information (on the spouse questionnaire or take-home applicator questionnaire; N = 44,086). Unconditional multiple logistic regression models were used to obtain adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

The results were consistent with those of prior studies of melanoma that indicate an association with measures of sun sensitivity. The highest category of body surface area (BSA; OR = 2.6; 95% CI, 1.5-4.4) and body mass index (BMI; OR = 2.5; 95% CI, 1.5-4.3) at age 20 were significantly associated with melanoma. There was some evidence for an association with BSA, but not BMI, at enrollment.

CONCLUSIONS

Obesity was associated with an increased risk of melanoma, indicating strategies to control obesity may result in risk reduction for melanoma.

Anthropometric factors and risk of melanoma in women: a pooled analysis

Anthropometric factors such as height, weight and body mass index are related to the occurrence of certain malignancies in women including cancers of the breast, ovary and endometrium. Several studies have investigated the relation between height and weight or body mass and the risk of cutaneous melanoma in women, but results have been inconsistent. We conducted a collaborative analysis of these factors using the original data from 8 case-control studies of melanoma in women (2,083 cases and 2,782 controls), with assessment of the potential confounding effects of socioeconomic, pigmentary and sun exposure-related factors. Women in the highest quartile of height had an increased risk of melanoma [pooled odds ratio (pOR) 1.3, 95% confidence interval (CI) 1.1-1.6]. We also found an elevated risk associated with weight gain in adult life of 2 kg or more (pOR 1.5, 95% CI 1.1-2.0). Stratifying by age at melanoma diagnosis (<50, >or=50 yr), we found this risk greater among women <50 yr of age. Associations were unaffected by adjustment for other known risk factors for melanoma. There was no evidence that the effects varied for different histologic subtypes of cutaneous melanoma. There was no association with body weight per se, body mass index, or body surface area, either recent or in young adulthood. In aggregate, data from these studies suggest that greater height and weight gain may be risk factors for cutaneous melanoma in women.

Superior survival of females among 10,538 Dutch melanoma patients is independent of Breslow thickness, histologic type and tumor site

BACKGROUND

Worldwide, female melanoma patients have superior survival compared with males, which is usually ascribed to earlier detection among women and/or a more favorable site distribution. We studied gender difference in melanoma survival in a large population-based setting after adjusting for tumor-related variables and offer clues for further research.

PATIENTS AND METHODS

A total of 10,538 patients diagnosed with melanoma from 1993 to 2004 in The Netherlands were included. Multivariate analyses were carried out to estimate adjusted relative excess risk (RER) of dying for men compared with women, adjusted for the patient and tumor characteristics.

RESULTS

Univariate relative survival analyses showed a RER of dying of 2.70 [95% confidence interval (CI) 2.38-3.06] for men compared with women. After adjusting for time period of diagnosis, region, age, Breslow thickness, histologic subtype, body site, nodal and metastatic status, a significant excess mortality risk was still present for males (RER 1.87, 95% CI 1.65-2.10). Among patients with advanced disease and in those < 45 or > or = 60, the adjusted risk estimates were similar.

CONCLUSIONS

The superior survival of women compared with men persisted after adjusting for multiple confounding variables indicating that factors other than stage at diagnosis and body site reduce mortality risk in female melanoma patients.

Menopause hormone replacement therapy and cancer risk: an Italian record linkage investigation

BACKGROUND

The effects of persistence with hormone replacement therapy (HRT) on the risk of hospitalization for cancer and of the route of HRT administration on the risk of breast and colorectal cancer were explored in a large cohort study.

PATIENTS AND METHODS

The 73 505 women residing in Lombardia (Italy), aged 45-75 years, who received at least one HRT prescription during 1998-2000 were followed until 2005. Among these, 3687 experienced cancer hospitalization. Proportional hazards model was fitted to estimate the association between cumulative HRT persistence and cancer risk.

RESULTS

Compared with women who took HRT for <6 months, those exposed for >2 years showed hazard ratios (HR) of 0.78 (95% confidence interval 0.68-0.92) for colorectal cancer and 1.34 (1.13-1.58) for breast cancer. HR for breast cancer associated with long-term use of transdermal and oral HRT were, respectively, 1.27 (1.07-1.51) and 2.14 (1.43-3.21).

CONCLUSIONS

Evidence that long-term use of HRT is associated with increased risk of breast cancer and decreased risk of colorectal cancer is supplied from this study from a southern European population. Our findings indicate that transdermal therapy might have lower effect than oral therapy in increasing breast cancer risk.

Malignant melanoma in the 21st century, part 1: epidemiology, risk factors, screening, prevention, and diagnosis

Malignant melanoma is an aggressive, therapy-resistant malignancy of melanocytes. The incidence of melanoma has been steadily increasing worldwide, resulting in an increasing public health problem. Exposure to solar UV radiation, fair skin, dysplastic nevi syndrome, and a family history of melanoma are major risk factors for melanoma development. The interactions between genetic and environmental risk factors that promote melanomagenesis are currently the subject of ongoing research. Avoidance of UV radiation and surveillance of high-risk patients have the potential to reduce the population burden of melanoma. Biopsies of the primary tumor and sampling of draining lymph nodes are required for optimal diagnosis and staging. Several clinically relevant pathologic subtypes have been identified and need to be recognized. Therapy for early disease is predominantly surgical, with a minor benefit noted with the use of adjuvant therapy. Management of systemic melanoma is a challenge because of a paucity of active treatment modalities. In the first part of this 2-part review, we discuss epidemiology, risk factors, screening, prevention, and diagnosis of malignant melanoma. Part 2 (which will appear in the April 2007 issue) will review melanoma staging, prognosis, and treatment.

Risk factors for skin cancers: a nested case–control study within the Nurses’ Health Study

BACKGROUND

Constitutional factors and sun exposure are associated with skin cancer risk. However, these relations are complex and differ according to skin cancer type.

METHODS

We examined the associations of constitutional risk factors and sun exposure with the risks of three types of skin cancer simultaneously and evaluated the interaction between constitutional susceptibility and sun exposure in a nested case-control study within the Nurses' Health Study [200 melanoma, 275 squamous cell carcinoma (SCC), and 283 basal cell carcinoma (BCC) cases, and 804 controls]. Information regarding skin cancer risk factors was obtained from the retrospective supplementary questionnaire.

RESULTS

Constitutional susceptibility was an independent risk factor for all three types of skin cancer. Sunlamp usage or tanning salon attendance was a risk factor for melanoma after adjusting for potential confounding variables (OR for ever vs never usage, 2.06, 95% CI 1.30-3.26). Higher sun exposure while wearing a bathing suit was an independent risk factor for all three types of skin cancer. We observed a significant interaction between constitutional susceptibility and sun exposure while wearing a bathing suit on melanoma risk (P, interaction, 0.03); women with the highest susceptibility and highest exposure had an OR of 8.37 (95% CI 3.07-22.84). This interaction was weaker and non-significant for SCC and BCC.

CONCLUSIONS

These data largely confirm past studies on risk factors for skin cancer but provide evidence of difference on the strength of these risk factors for melanoma compared with SCC and BCC.