The Danish case-control study of cutaneous malignant melanoma. III. Hormonal and reproductive factors in women

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.

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.

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.

Estrogen Receptors and Melanoma: A Review

In the last three decades cutaneous melanoma has been widely investigated as a steroid hormone-sensitive cancer. Following this hypothesis, many epidemiological studies have investigated the relationship between estrogens and melanoma. No evidence to date has supported this association due to the great complexity of genetic, external and environmental factors underlying the development of this cancer. Molecular mechanisms through which estrogen and their receptor exert a role in melanoma genesis are still under investigation with new studies increasingly focusing on the discovery of new molecular targets for therapeutic treatments.

The Influence of Female Hormones on Malignant Melanoma

Several lines of biological evidence have suggested a relationship between the behaviour of melanocytes and cutaneous malignant melanoma (CMM) and the action of female hormones. The present overview, however, indicates that the effect of reproductive, menstrual and hormonal factors, including oral contraceptives, on onset and outcome of CMM must be very weak, if any. The only consistent findings which may suggest a role of female hormones on CMM seem to be: 1) a different distribution by anatomic site in men and women, and 2) a more favorable outcome of CMM in women as compared to men. Neither of them, however, necessarily implies a direct effect of female hormones on CMM.

Niacin intake and risk of skin cancer in US women and men

A recent clinical trial found a protective role of niacinamide, a derivative of niacin, against skin cancer recurrence. However, there is no epidemiologic study to assess the association between niacin intake and risk of skin cancer [basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma]. We prospectively evaluated whether total, dietary and supplemental niacin intake was associated with skin cancer risk based on 72,308 women in the Nurses' Health Study (1984-2010) and 41,808 men in the Health Professionals Follow-up Study (1986-2010). Niacin intake was assessed every 2 to 4 years during follow-up and cumulative averaged intake. Cox proportional hazard models were used to compute the hazard ratios (HR) and 95% confidence intervals (CI) and cohort-specific results were pooled using a random-effects model. During the follow-up, we documented 23,256 BCC, 2,530 SCC and 887 melanoma cases. Total niacin intake was inversely associated with SCC risk; the pooled HR for top vs. bottom quintiles was 0.84 (95% CI = 0.74-0.95; ptrend  = 0.08). However, there were a marginally positive association between total niacin intake and BCC risk; the pooled HR for top versus bottom quintiles was 1.05 (95% CI = 1.01-1.10; ptrend  < 0.01). Higher total niacin intake was also marginally positively associated with melanoma risk in men, but not in women. The results were similar in stratified analyses according to sun exposure related factors and by body location of melanoma and SCC. Our study supports a potential beneficial role of niacin intake in relation to SCC but not of BCC or melanoma.

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.

Correlation between fertility drugs use and malignant melanoma incidence: the state of the art

The relationship between fertility, reproductive hormones, and risk of malignant melanoma has acquired much interest in recent years. Melanocytes are hormonally responsive cells, and some in vitro studies demonstrated that estrogen hormones stimulate the growth of melanocytes. Moreover, estrogen receptors have been identified in melanoma cells, as well as in melanocytic nevi and in normal skin. Some evidences suggest a possible link between fertility treatments and the increased risk of malignant melanoma. This article addresses this association through a scrupulous search of the literature published thus far. The aim of this review is to determine the incidence of malignant melanoma in women treated with fertility drugs and to examine if the exposure to fertility treatments really increases the risk of malignant melanoma. In particular, our analysis focused on the different types of drugs and different treatment schedules used. Finally, this study provides additional insights regarding the long-term relationships between fertility drugs and the risk of malignant melanoma.

Immunomodulatory effects of sex hormones: requirements for pregnancy and relevance in melanoma

Similarities between the pathologic progression of cancer and the physiologic process of placentation (eg, proliferation, invasion, and local/systemic tolerance) have been recognized for many years. Sex hormones such as human chorionic gonadotropin, estrogens, progesterone, and others contribute to induction of immunologic tolerance at the beginning of gestation. Sex hormones have been shown to play contributory roles in the growth of cancers such as breast cancer, prostrate cancer, endometrial cancer, and ovarian cancer, but their involvement as putative mediators of the immunologic escape of cancer is still being elucidated. Herein, we compare the emerging mechanism by which sex hormones modulate systemic immunity in pregnancy and their potentially similar role in cancer. To do this, we conducted a PubMed search using combinations of the following keywords: "immune regulation," "sex hormones," "pregnancy," "melanoma," and "cancer." We did not limit our search to specific publication dates. Mimicking the maternal immune response to pregnancy, especially in late gestation, might aid in design of better therapies to reconstitute endogenous antitumor immunity and improve survival.

A unique gender difference in early onset melanoma implies that in addition to ultraviolet light exposure other causative factors are important

Using US SEER17 Registry data, age-specific melanoma incidence rates were calculated and comparisons were made between males and females. Relative Risk (RR) for males and females in each age group was computed and compared with that from Nordic Cancer Registry data set and to that for non-melanoma skin cancer (NMSC). For age groups 44 and younger, females showed higher incidence rates, with a peak difference at age 20-24 (RR = 2.01, 95% CI = 1.21-3.33). Males exhibited higher incidence rates after age 44. The same bimodal gender difference was confirmed by the Nordic Cancer Registry data set, but it was not observed for NMSC, which is known to be strongly associated with cumulative exposure to solar UV radiation. We conclude that exposure to solar ultraviolet (UV) radiation is the major causative factor for melanoma at older age (>44 yr), but that other factors may play a role in early onset melanomas, particularly in females.

The Effects of Twins, Parity and Age at First Birth on Cancer Risk in Swedish Women

The effect of reproductive history on the risk of cervical, colorectal and thyroid cancers and melanoma has been explored but the results to date are inconsistent. We aimed to examine in a record- linkage cohort study the risk of developing these cancers, as well as breast, ovarian and endometrial cancers, among mothers who had given birth to twins compared with those who had only singleton pregnancies. Women who delivered a baby in Sweden between 1961 and 1996 and who were 15 years or younger in 1961 were selected from the Swedish civil birth register and linked with the Swedish cancer registry. We used Poisson regression to assess associations between reproductive factors and cancer. Twinning was associated with reduced risks of breast, colorectal, ovarian and uterine cancers, although no relative risks were statistically significant. The delivery of twins did not increase the risk of any cancers studied. Increasing numbers of maternities were associated with significantly reduced risks of all tumors except thyroid cancer. We found positive associations between a later age at first birth and breast cancer and melanoma, while there were inverse associations with cervix, ovarian, uterine and colorectal cancers. These findings lend weight to the hypothesis that hormonal factors influence the etiology of colorectal cancer in women, but argue against any strong effect of hormones on the development of melanoma or tumors of the thyroid.

Melanoma in adolescents and young adults (ages 15-39 years): United States, 1999-2006

BACKGROUND

Invasive melanoma of the skin is the third most common cancer diagnosed among adolescents and young adults (aged 15-39 years) in the United States. Understanding the burden of melanoma in this age group is important to identifying areas for etiologic research and in developing effective prevention approaches aimed at reducing melanoma risk.

METHODS

Melanoma incidence data reported from 38 National Program of Cancer Registries and/or Surveillance Epidemiology and End Results statewide cancer registries covering nearly 67.2% of the US population were used to estimate age-adjusted incidence rates for persons 15-39 years of age. Incidence rate ratios were calculated to compare rates between demographic groups.

RESULTS

Melanoma incidence was higher among females (age-adjusted incidence rates = 9.74; 95% confidence interval 9.62-9.86) compared with males (age-adjusted incidence rates = 5.77; 95% confidence interval 5.68-5.86), increased with age, and was higher in non-Hispanic white compared with Hispanic white and black, American Indians/Alaskan Natives, and Asian and Pacific Islanders populations. Melanoma incidence rates increased with year of diagnosis in females but not males. The majority of melanomas were diagnosed on the trunk in all racial and ethnic groups among males but only in non-Hispanic whites among females. Most melanomas were diagnosed at localized stage, and among those melanomas with known histology, the majority were superficial spreading.

LIMITATIONS

Accuracy of melanoma cases reporting was limited because of some incompleteness (delayed reporting) or nonspecific reporting including large proportion of unspecified histology.

CONCLUSIONS

Differences in incidence rates by anatomic site, histology, and stage among adolescents and young adults by race, ethnicity, and sex suggest that both host characteristics and behaviors influence risk. These data suggest areas for etiologic research around gene-environment interactions and the need for targeted cancer control activities specific to adolescents and young adult populations.

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.

Biologic markers of sun exposure and melanoma risk in women: pooled case-control analysis

A model has been proposed whereby melanomas arise through two distinct pathways dependent on the relative influence of host susceptibility and sun exposure. Such pathways may explain site-specific patterns of melanoma occurrence. To explore this model, we investigated the relationship between melanoma risk and general markers of acute (recalled sunburns) and chronic (prevalent solar keratoses) sun exposure, stratified by anatomic site and host phenotype. Our working hypothesis was that head and neck melanomas have stronger associations with solar keratoses and weaker associations with sunburn than trunk melanomas. We conducted a collaborative analysis using original data from women subjects of 11 case-control studies of melanoma (2,575 cases, 3,241 controls). We adjusted for potential confounding effects of sunlamp use and sunbathing. The magnitude of sunburn associations did not differ significantly by melanoma site, nevus count or histologic subtype of melanoma. Across all sites, relative risk of melanoma increased with an increasing number of reported lifetime "painful" sunburns, lifetime "severe" sunburns and "severe" sunburns in youth (p(trend) < 0.001), with pooled odds ratios (pORs) for the highest category of sunburns versus no sunburns of 3.22 [95% confidence interval (CI) 2.04-5.09] for lifetime "painful" sunburns, 2.10 (95%CI 1.30-3.38) for lifetime "severe" sunburns and 2.43 (95%CI 1.61-3.65) for "severe" sunburns in youth. Solar keratoses strongly increased the risk of head and neck melanoma (pOR 4.91, 95%CI 2.10-11.46), but data were insufficient to assess risk for other sites. Reported sunburn is strongly associated with melanoma on all major body sites.

Association of MDM2 SNP309, age of onset, and gender in cutaneous melanoma

PURPOSE

In certain cancers, MDM2 SNP309 has been associated with early tumor onset in women. In melanoma, incidence rates are higher in women than in men among individuals less than 40 years of age, but among those older than 50 years of age, melanoma is more frequent in men than in women. To investigate this difference, we examined the association among MDM2 SNP309, age at diagnosis, and gender among melanoma patients.

EXPERIMENTAL DESIGN

Prospectively enrolled melanoma patients (N = 227) were evaluated for MDM2 SNP309 and the related polymorphism, p53 Arg72Pro. DNA was isolated from patient blood samples, and genotypes were analyzed by PCR-restriction fragment length polymorphism. Associations among MDM2 SNP309, p53 Arg72Pro, age at diagnosis, and clinicopathologic features of melanoma were analyzed.

RESULTS

The median age at diagnosis was 13 years earlier among women with a SNP309 GG genotype (46 years) compared with women with TG+TT genotypes (59 years; P = 0.19). Analyses using age dichotomized at each decade indicated that women with a GG genotype had significantly higher risks of being diagnosed with melanoma at ages <50 years compared with women >or=50 years, but not when the comparison was made between women <60 and >or=60 years. At ages <50 years, women with a GG genotype had a 3.89 times greater chance of being diagnosed compared with women with TG+TT genotypes (P = 0.01). Similar observations were not seen among men.

CONCLUSIONS

Our data suggest that MDM2 may play an important role in the development of melanoma in women. The MDM2 SNP309 genotype may help identify women at risk of developing melanoma at a young age.

Nevus density and melanoma risk in women: a pooled analysis to test the divergent pathway hypothesis

A "divergent pathway" model for the development of cutaneous melanoma has been proposed. The model hypothesizes that melanomas occurring in people with a low tendency to develop nevi will, on average, arise more commonly on habitually sun-exposed body sites such as the head and neck. In contrast, people with an inherent propensity to develop nevi will tend to develop melanomas most often on body sites with large melanocyte populations, such as on the back. We conducted a collaborative analysis to test this hypothesis using the original data from 10 case-control studies of melanoma in women (2,406 cases and 3,119 controls), with assessment of the potential confounding effects of socioeconomic, pigmentary and sun exposure-related factors. Higher nevus count on the arm was associated specifically with an increased risk of melanoma of the trunk (p for trend = 0.0004) and limbs (both upper and lower limb p for trends = 0.01), but not of the head and neck (p for trend = 0.25). The pooled odds ratios for the highest quartile of nonzero nevus count versus none were 4.6 (95% confidence interval (CI) 2.7-7.6) for melanoma of the trunk, 2.0 (95% CI 0.9-4.5) for the head and neck, 4.2 (95% CI 2.3-7.5) for the upper limbs and 3.4 (95% CI 1.5-7.9) for the lower limbs. Aggregate data from these studies suggest that high nevus counts are strongly associated with melanoma of the trunk but less so if at all of the head and neck. This finding supports different etiologic pathways of melanoma development by anatomic site.

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.

Relation of body mass index to cancer risk in 362,552 Swedish men

BACKGROUND

Obesity has been linked with increased risk for cancers of the colon, kidney, breast, endometrium and gallbladder. For other cancer sites, the relationship with obesity is less well quantified, and the effect of weight change on cancer risk is unclear.

METHODS

We examined the health records of 362,552 Swedish men who underwent at least one physical examination from 1971 to 1992, and were followed until death or the end of 1999. Incident cancer cases were identified by linkage to the Swedish cancer registry. Poisson regression models were used to estimate relative risks of cancer for both body-mass index (BMI) at baseline exam and, in a subgroup of 107,815 men, change in BMI after six years of follow-up, adjusting for age and smoking status.

RESULTS

Compared to men of normal weight, obese men had a significantly increased risk of all cancers combined (RR = 1.1; 95% CI = 1.0-1.2). The risks were most pronounced for esophageal adenocarcinoma (RR = 2.7; 95% CI = 1.3-5.6), renal cell carcinoma (RR = 1.8; 95% CI = 1.4-2.4), malignant melanoma (RR = 1.4; 95% CI = 1.1-1.7), and cancers of the colon (RR = 1.7; 95% CI = 1.5-2.0), rectum (RR = 1.4; 95% CI = 1.1-1.7), and liver (RR = 3.6; 95% CI = 2.6-5.0). Risk of esophageal squamous cell carcinoma was elevated for underweight men whose BMI was less than 18.5 (RR = 3.1; 95% CI = 1.1-8.3). An excess risk for cancers of the pancreas and connective tissue was observed only among nonsmokers. Compared to men whose weight remained stable, men with more than a 15% increase in BMI after six years of follow-up had an elevated risk of pancreas and renal cell cancers.

CONCLUSIONS

Obesity and weight gain increase the risk for several forms of cancer in men, and underscore the need for further study into carcinogenic mechanisms and preventive interventions.

Pregnancy History and Incidence of Melanoma in Women: A Pooled Analysis

There is evidence that pregnancy history including age at first birth and parity may play a role in risk of cutaneous melanoma in women, although, epidemiological findings are inconsistent. We conducted a collaborative analysis of these factors using the original data from ten completed case-control studies (2391 cases and 3199 controls), and assessed the potential confounding effects of socioeconomic, pigmentary, and sun exposure-related factors. We found no overall association with ever having a live birth (pooled odds ratio (pOR) 0.95, 95% confidence interval (CI) 0.67-1.35). However, we detected a reduced risk of melanoma among women with higher parity (> or = 5 versus no live births pOR 0.76, 95% CI 0.49-1.18, each live birth pOR 0.95, 95% CI 0.91-0.99, p trend = 0.05). Women with both earlier age at first birth (e.g., <20 years) and higher parity (e.g., > or = 5 live births) had a particularly lower risk than women with later age at first birth (e.g., > or = 25 years) and lower parity (e.g., <5 live births) (pOR 0.33, 95% CI 0.14-0.75). The results are compatible with an effect of reproductive history-related factors on melanoma risk, but also could reflect differences in other factors, such as sun exposure history.

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

PURPOSE

We examined the role of personal host characteristics in relation to cutaneous malignant melanoma (CMM) among women, with a particular focus on hormonal and reproductive factors.

METHODS

A case-control study conducted in Italy between 1992 and 1994, including 316 women with incident, histologically confirmed CMM and 308 controls, admitted to the same network of hospitals as cases for acute, non-dermatological, and non-neoplastic conditions.

RESULTS

CMM was significantly associated with body mass index (kg/m(2)) (odds ratio [OR]=1.96 for > or =27 compared with < 23) and body surface area (m(2)) (OR=1.68 for > or =1.71 compared with < 1.59), eye color (OR=1.74 for green/hazel compared with brown), solar lentigines (OR=1.47), and number of melanocytic nevi (OR=3.39 for total number of nevi > or =16 compared with < 5). Age at first (OR=2.69 for > or =27 compared with < 23 years) and last birth (OR=2.13 for > or =31 compared with < 27 years) were associated with the risk of CMM, whereas other reproductive, menstrual, and hormonal factors, including menopause, number of live-births and abortions, use of oral contraceptives, and hormone replacement therapy were not significantly associated.

CONCLUSIONS

Our results confirm findings from previous studies on the role of major recognized risk factors for CMM, and add further evidence of an absence of a consistent association between hormonal and reproductive factors and CMM risk.

Malignant Melanoma in Pregnancy

This article provides a concise overview of issues relating to melanoma and pregnancy, including pregnancy-associated risk and prognosis, and briefly summarizes results from relevant reports that have been published in recent years. The bulk of evidence amassed over the past half century suggests that pregnancy does not significantly affect the risk of developing malignant melanoma. Further, pregnancy does not seem adversely to influence overall survival from the disease. Most studies found no difference in overall survival between pregnant and nonpregnant women with melanoma. Recent reports from large-scale, population-based studies support these conclusions.

Childhood and Adult Cancer in Twins: Evidence from the Utah Genealogy

OBJECTIVE

Evidence suggests that the in utero environment may contribute to subsequent development of cancers in childhood and adulthood. Raised levels of estrogen during pregnancy may be the primary in utero etiologic factor. Mothers of twins have higher estrogen levels during pregnancy than mothers of singletons, therefore, assessment of cancer risk in twins may be informative.

METHOD

We conducted a retrospective cohort study of cancer among twin and singleton newborns selected from the Utah Population Database, matched on birth year and sex. Cancer diagnoses were determined by linkage with the Utah state cancer register. Relative rates of all cancers in childhood and in adulthood in twins compared with singletons, and for specific cancers including testicular, breast and melanoma, were calculated using Poisson regression.

RESULTS

Twin (35,271) and singleton (74,199) births were identified, among whom there were 336 and 691 cancer diagnoses, respectively. The relative risk (RR) of childhood cancer in twins compared with singletons was 0.82 [95% confidence interval (CI) 0.55-1.24] and of adult cancer was 1.06 (0.92-1.22). We found nonsignificant increases in risk among adult twins for cancers of the breast, prostate, testis, lymphatic system, thyroid, and large bowel. The largest departures from unity were for testicular cancer (RR 1.47; 95% CI, 0.73-2.95) and melanoma (RR 0.67; 95% CI, 0.42-1.06).

CONCLUSIONS

These results are consistent with the body of evidence suggesting that twins have a reduced risk of cancer in childhood. Although there is no overall differential in adult cancer risk, these data support the hypothesis that the in utero environment may play an important role in specific cancers.

Contraception for teenagers and young adults with cancer

Adolescence can be an extremely stressful time for all concerned. When this period is then compounded by the development of cancer, formidable and seemingly insurmountable problems may be perceived. Cancer in adolescence is relatively uncommon, with an annual incidence rate in western populations of approximately 150-200 per million. Five-year survival of patients diagnosed around 1990 exceeded 70% in the United Kingdom (UK) and United States of America (USA), and adolescents with cancer are likely to remain fertile. Further advances in therapeutic modalities are creating a generation of adolescents and young adults with cancer who can now aspire to the same sexual and reproductive activities as their healthy peers. This then raises the issue of avoidance of undesired pregnancy during and after treatment. This article aims to address the contraceptive needs of adolescents and young adults undergoing treatment for cancer.

Effect of pregnancy on survival in women with cutaneous malignant melanoma

PURPOSE

An adverse influence of pregnancy on the risk of death in women with cutaneous melanoma was suggested historically by anecdotal reports. Previous studies included small numbers of women observed for short periods.

METHODS

Using data from the Swedish National and Regional Registries, we performed a retrospective cohort study of all Swedish women who were diagnosed with cutaneous melanoma during their reproductive period, from January 1, 1958, to December 31, 1999. The relationship between pregnancy status at the diagnosis of melanoma and overall survival was examined in multivariable proportional-hazards models.

RESULTS

The cohort comprised 185 women (3.3%) diagnosed with melanoma during pregnancy and 5,348 (96.7%) women of the same childbearing age diagnosed with melanoma while not pregnant. There was no statistically significant difference in overall survival between pregnant and nonpregnant groups (log-rank chi(2)1[r] = 0.84, P = .361). Pregnancy status at the time of diagnosis of melanoma was not related to survival in a multivariable Cox model in the 2,101 women (hazard ratio for death in the pregnant group was 1.08; 95% CI, 0.60 to 1.93). In the multivariable analysis, pregnancy status after diagnosis of melanoma was not a significant predictor of survival (hazard ratio for death in women who had pregnancy subsequent to the diagnosis of melanoma was 0.58; 95% CI, 0.32 to 1.05).

CONCLUSION

The survival of pregnant women with melanoma is not worse than the survival of nonpregnant women with melanoma. Pregnancy subsequent to the diagnosis of primary melanoma was not associated with an increased risk of death.

Hormone replacement therapy after surgery for stage 1 or 2 cutaneous melanoma

A total of 206 women were followed for a minimum of 5 years after primary melanoma surgery to establish if hormone replacement therapy (HRT) adversely affected prognosis. In all, 123 had no HRT and 22 have died of melanoma; 83 had HRT for varying periods and one has died of melanoma. After controlling for known prognostic factors, we conclude that HRT after melanoma does not adversely affect prognosis.

Melanoma etiology: where are we?

Melanoma incidence rates are rising rapidly, particularly in older men. Older men are also more likely to have thick melanomas, which confer high mortality and morbidity. The reasons for the rate of increase are not known; increasing sun and UV exposure, however, is the major hypothesized explanation. In the past several years, two major susceptibility genes for melanoma, CDKN2A and CDK4, have been identified, but the two genes together account for a minority of familial melanoma. Other high-risk susceptibility genes are being sought actively. Genetic epidemiologic studies suggest that penetrance of each of the two identified genes is altered by other factors, either genetic or environmental. Epidemiologic studies have also identified other major host factors important in the development of melanoma. In European, North American, and Australian populations, the presence of clinically identified dysplastic nevi confers greatly increased risk of melanoma. A new measure of sun exposure, based on individual residential history, confers substantially increased risk of melanoma. Recent surveys of sun behavior in the US reveal extensive sunburning and use of tanning beds in adolescents and adults. Sun protective behaviors are not as prevalent as in Australia, where population rates of melanoma are stabilizing.

A pooled analysis of 10 case-control studies of melanoma and oral contraceptive use

Data regarding the effects of oral contraceptive use on women's risk of melanoma have been difficult to resolve. We undertook a pooled analysis of all case-control studies of melanoma in women completed as of July 1994 for which electronic data were available on oral contraceptive use along with other melanoma risk factors such as hair colour, sun sensitivity, family history of melanoma and sun exposure. Using the original data from each investigation (a total of 2391 cases and 3199 controls), we combined the study-specific odds ratios and standard errors to obtain a pooled estimate that incorporates inter-study heterogeneity. Overall, we observed no excess risk associated with oral contraceptive use for 1 year or longer compared to never use or use for less than 1 year (pooled odds ratio (pOR)=0.86; 95% CI=0.74-1.01), and there was no evidence of heterogeneity between studies. We found no relation between melanoma incidence and duration of oral contraceptive use, age began, year of use, years since first use or last use, or specifically current oral contraceptive use. In aggregate, our findings do not suggest a major role of oral contraceptive use on women's risk of melanoma.

Focus on primary care: from nevus to neoplasm: myths of melanoma in pregnancy

Malignant melanoma is one of the few malignancies that regularly affect women during their childbearing years. Additionally, the incidence of melanoma has been increasing over the last several decades. Early diagnosis of stage I disease may lead to curative therapy; thus it is important for physicians and midwives to do a full examination of the skin. However, the myth that nevi may naturally grow or change during pregnancy has been shown not to be true and should not delay a diagnostic evaluation of a suspicious nevus. Older studies had theorized a worse outcome for pregnant women with melanoma. However, multiple controlled series and investigations have found that stage for stage this cancer is not affected adversely by pregnancy. Prognosis, recurrence, and incidence of melanoma seemed to be unaffected. Estrogen-containing oral contraceptives, as well as hormone replacement therapy, have no adverse affect on the disease.

Estrogen and skin. An overview

As the population of postmenopausal women increases, interest in the effects of estrogen grows. The influence of estrogen on several body systems has been well-documented; however, one area that has not been explored is the effects of estrogen on skin. Estrogen appears to aid in the prevention of skin aging in several ways. This reproductive hormone prevents a decrease in skin collagen in postmenopausal women; topical and systemic estrogen therapy can increase the skin collagen content and therefore maintain skin thickness. In addition, estrogen maintains skin moisture by increasing acid mucopolysaccharides and hyaluronic acid in the skin and possibly maintaining stratum corneum barrier function. Sebum levels are higher in postmenopausal women receiving hormone replacement therapy. Skin wrinkling also may benefit from estrogen as a result of the effects of the hormone on the elastic fibers and collagen. Outside of its influence on skin aging, it has been suggested that estrogen increases cutaneous wound healing by regulating the levels of a cytokine. In fact, topical estrogen has been found to accelerate and improve wound healing in elderly men and women. The role of estrogen in scarring is unclear but recent studies indicate that the lack of estrogen or the addition of tamoxifen may improve the quality of scarring. Unlike skin aging, the role of endogenous and exogenous estrogen in melanoma has not been well established.

A study of infertility treatment and melanoma

This study examined the possible association between melanoma and exposure to fertility drugs, specifically clomiphene citrate, human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG). A cohort of 3186 women who attended a fertility clinic between 1 January 1980 and 31 December 1990 was studied; by January 1996, 14 women had been diagnosed with primary melanoma. Details of fertility treatment were extracted from the clinical records. The incidence of melanoma in the cohort resembled that of the female Queensland population (standardized incidence ratio = 0.89, 95% confidence interval [CI] = 0.54-1.48). Exposure to clomiphene citrate, HMG or HCG did not affect the incidence of melanoma. Women with infertile partners who were treated with fertility drugs were at increased risk of melanoma (odds ratio [OR] = 3.17, 95% CI = 1.01-9.98). Compared with women exposed only to clomiphene citrate and HMG, a lower incidence of melanoma was observed among those who received HCG as well (OR = 0.10, 95% CI = 0.02-0.42). Women exposed to two or more cycles of either clomiphene citrate (OR = 0.27, 95% CI = 0.08-0.94) or HMG (OR = 0.23, 95% CI = 0.07-0.84) had a significant reduction in melanoma risk compared with women exposed to no or one cycle. In summary, a woman's infertility per se was not found to be associated with melanoma, while exposure to fertility drugs was positively associated with melanoma in women with infertile partners and negatively associated in women with low doses of fertility drugs.

Two-stage methods for the analysis of pooled data

Epidemiologic studies of disease often produce inconclusive or contradictory results due to small sample sizes or regional variations in the disease incidence or the exposures. To clarify these issues, researchers occasionally pool and reanalyse original data from several large studies. In this paper we explore the use of a two-stage random-effects model for analysing pooled case-control studies and undertake a thorough examination of bias in the pooled estimator under various conditions. The two-stage model analyses each study using the model appropriate to the design with study-specific confounders, and combines the individual study-specific adjusted log-odds ratios using a linear mixed-effects model; it is computationally simple and can incorporate study-level covariates and random effects. Simulations indicate that when the individual studies are large, two-stage methods produce nearly unbiased exposure estimates and standard errors of the exposure estimates from a generalized linear mixed model. By contrast, joint fixed-effects logistic regression produces attenuated exposure estimates and underestimates the standard error when heterogeneity is present. While bias in the pooled regression coefficient increases with interstudy heterogeneity for both models, it is much smaller using the two-stage model. In pooled analyses, where covariates may not be uniformly defined and coded across studies, and occasionally not measured in all studies, a joint model is often not feasible. The two-stage method is shown to be a simple, valid and practical method for the analysis of pooled binary data. The results are applied to a study of reproductive history and cutaneous melanoma risk in women using data from ten large case-control studies.

Microanalysis of melanins in mammalian hair by alkaline hydrogen peroxide degradation: identification of a new structural marker of pheomelanins

A highly sensitive, easy-to-perform method for melanin analysis in pigmented tissues based on alkaline hydrogen peroxide degradation has been developed and accomplishes simultaneous determination of eumelanins and pheomelanins. Pyrrole-2,3,5- tricarboxylic acid, the typical eumelanin marker, was obtained in higher yields than in previous procedures. A benzothiazole acid, 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole, characterized in our previous studies as a specific marker of pheomelanins, and the newly identified 1,3-thiazole-2,4, 5-tricarboxylic acid were also used for pigment analysis. Optimal yields of the pigment markers were obtained at 24 h reaction time. Pyrrole-2,3,5-tricarboxylic acid, 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole, and 1, 3-thiazole-2,4,5- tricarboxylic acid were quantified in a single chromatographic analysis without fractionation or work up of the degradation mixture. The linearity (linearity coefficient from 0.997 to 0.999) was excellent and the inter-assay (percentage coefficient of variation values in the range 0.2-2, n = 6) and intra-assay (percentage coefficient of variation values </= 0.4) reproducibility of the method was very satisfactory. A variety of mammalian hairs including coat color mutant mice and human hairs were used to evaluate the method. All the phenotypically pheomelanic hairs gave 1, 3-thiazole-2,4,5-tricarboxylic acid in variable yields, whereas 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole was obtained only from some of the red hair samples examined. Notably, a marked tendency to actinic damage, as evidenced by determination of the minimal erythema dose, was exhibited by those subjects whose hair afforded the highest 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole yields. This suggests that 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole represents a new biogenetic marker for predicting individuals at high risk for skin cancer and melanoma.

Oral contraceptive use and risk of melanoma in premenopausal women

Melanoma has been increasing in white populations. Incidence rates rise steeply in women until about age 50, suggesting oestrogen as a possible risk factor. Oestrogens can increase melanocyte count and melanin content and cause hyperpigmentation of the skin. We examined prospectively the association between oral contraceptive (OC) use and diagnoses of superficial spreading and nodular melanoma among 183,693 premenopausal white women in the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHS II) cohorts. One hundred and forty six cases were confirmed in NHS during follow-up from 1976 to 1994, and 106 cases were confirmed in NHS II from 1989 to 1995. Skin reaction to sun exposure, sunburn history, mole counts, hair colour, family history of melanoma, parity, height and body mass index were also assessed and included in logistic regression models. A significant twofold increase in risk of melanoma (relative risk (RR) = 2.0, 95% confidence interval (CI) 1.2-3.4) was observed among current OC users compared to never users. Risk was further increased among current users with 10 or more years of use (RR = 3.4, 95% CI 1.7-7.0). Risk did not appear elevated among past OC users, even among those with longer durations of use, and risk did not decline linearly with time since last use. In conclusion, risk of premenopausal melanoma may be increased among women who are current OC users, particularly among those with longer durations of use. Further research is needed to determine whether low-dose oestrogen pills in particular are associated with an increase in risk and to describe possible interactions between OC use and sun exposure or other risk factors for melanoma.

Cutaneous malignant melanoma in women and the role of oral contraceptives

The role of oral contraceptives (OC) in the aetiology of cutaneous malignant melanoma (CMM) has been controversially discussed over the last two decades. In an extensive literature search we identified 18 case-control studies, published between 1977 and 1996, offering information on this relationship. Using a meta-analytical approach we combined the study-specific risk estimates and derived a summary odds ratio of 0.95 (95% confidence interval: 0.87-1.04). Based on the data of 3796 cases and 9442 controls, we thus found no evidence for an aetiological role of OC use in the development of CMM.

Cutaneous malignant melanoma: association with height, weight and body-surface area. a prospective study in Norway

To investigate whether anthropometric indices as body height, body-mass index (BMI) and body-surface area (BSA) have any influence on the risk of cutaneous malignant melanoma (CMM), we analyzed height and weight data from a Norwegian screening survey running between 1963 and 1975 and comprising 1.3 million individuals followed for 14 to 26 years. Among females, CMM was diagnosed in 2814 incident cases, while the number among males was 2144 during 22,988,345 person-years of follow-up. With adjustment for age, birth cohort, geographic region and BMI, the risk for CMM increased significantly with increasing quintiles of height in both sexes. The tallest persons were at greater relative risk than the shortest ones: 1.60 and 1.59 in males and females respectively. This positive association was also found for CMM localized on face and trunk in both sexes, and in the lower limbs only in females. Males in the highest quintile of BMI had a relative risk for CMM of 1.26 compared with the lowest quintile, while a non-significant negative association were found in obese females. This negative association increased and was significant for CMM located on the trunk and lower limbs in females. Among males we observed a consistent association between BSA and risk of CMM similar to that for height. These relationships between anthropometric indices and CMM are discussed according to factors which promote growth, among which nutrition, social class and hormones are the most important.

Malignant melanoma of the vulva and vagina. Trends in incidence, age distribution, and long-term survival among 245 consecutive cases in Sweden 1960-1984

BACKGROUND

Malignant melanomas of the vulva and vagina are rare tumors located in areas of the body not exposed to ultraviolet radiation. Investigations comprising large consecutive population-based series of patients with these diseases have not been published previously, to the knowledge of the authors.

METHODS

Trends in incidence, age distribution, and prognosis were investigated among 219 consecutive cases of malignant melanoma of the vulva and 26 cases in the vagina, reported to the Swedish National Cancer Registry and representing virtually all primary tumors of that kind in Sweden during a 25-year period, 1960-1984.

RESULTS

On average, 75% of the patients with vulvar melanoma and 73% with vaginal melanoma were older than 60 years of age. The mean age increased slightly but not significantly during the period. The age-standardized incidence of vulvar melanoma decreased from 0.27 to 0.14 per 100,000 Swedish women, or by 3% per year. The observed 5-year survival rate of patients with vulvar melanoma was 35%, and the relative survival rate was 47%. The observed and relative survival rates at 10 years were 23% and 44%, respectively. Observed and relative survival rates among patients with vaginal melanoma after 5 years were 13% and 18%, respectively.

CONCLUSIONS

Accordingly, there was a decreasing incidence of vulvar and vaginal melanoma over the observed 25 years. This is in contrast to the trends in incidence for cutaneous melanomas in Sweden, which, during the same time period, increased almost 6% per year.