Reproductive factors, hormone use and melanoma risk: an Australian prospective cohort study

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.

Female melanoma and estrogen receptors expression: an immunohistochemical pilot study

Epidemiologic data highlight sex differences in melanoma outcome. A putative role of sex hormones is still under investigation. Very few laboratory investigations have focused on the level of expression of estrogen receptors in melanoma. We evaluated the presence of estrogen receptors alpha (ERα) and beta (ERβ) in melanoma specimens from female patients with a previous history of breast carcinoma (BC). Moreover, another group of female patients undergoing ovarian stimulation (OS) were also compared to two control groups matched for age and melanoma staging. The study was performed at the IRCCS Policlinico di Sant'Orsola Hospital's Melanoma Unit from January 2017 to December 2019. The nuclear and cytoplasmatic immunohistochemical staining was evaluated and scored by the percentage of stained tumour cells: 0 (≤20%), 1 (21-50%) or 2 (≥50%). Twenty-eight specimens were analysed. ERβ nuclear presence was detected in all cases of women with a history of breast cancer. Cytoplasmatic ERβ was clearly expressed with a score of 2 in seven cases. In the respective control group, nuclear and cytoplasmatic ERβ expression was much lower. A cytoplasmatic ERα positivity was also detected in almost all cases. In the second group of women who experienced ovarian stimulation for Assisted Reproductive Technology (ART), a lower abundance of nuclear ERs was detected. Conversely, cytoplasmatic ERβ and α expression ranged widely. Melanoma of women treated with anti-estrogen therapy is generally more prone to express estrogen receptors compared with women of the same age and CM staging but also compared with women in fertile age with and without a history of OS.

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.

Reproductive factors, hormone use, and incidence of melanoma in a cohort of US Radiologic Technologists

STUDY QUESTION

Are reproductive factors and exogenous hormone use associated with incidence of cutaneous melanoma while accounting for ultraviolet radiation (UVR) exposure across different life periods and sun sensitivity factors?

SUMMARY ANSWER

Earlier age at menarche and late age at first birth, but not other estrogen-related factors were associated with an increased incidence rate of melanoma, with higher risks observed for earlier age at menarche and light hair color at age 15 years.

WHAT IS KNOWN ALREADY

Although estrogens have been recognized as photosensitizing, previous studies have reported inconsistent findings for the association of melanoma with estrogen-related factors. Most have not collected detailed skin cancer risk factors and have not thoroughly investigated effect modification by ambient UVR and sun sensitivity.

STUDY DESIGN, SIZE, DURATION

Participants in the US Radiologic Technologists study, an occupational cohort of 146 022 radiologic technologists (73% women), were included and followed during the four time periods (1983-1989, 1994-1998, 2003-2005 and 2012-2014).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Non-Hispanic white female participants who completed both the second (baseline) and third questionnaires, and did not report having cancer (except keratinocyte carcinoma) at baseline, were included and followed from their age at completion of the second (baseline) questionnaire until the earlier of first primary cancer diagnosis, including invasive melanoma of the skin, or completion of either the third or fourth questionnaire. Reproductive and exogenous hormonal factors were ascertained from the second (baseline) questionnaire, which also collected information on demographic, lifestyle factors and sun sensitivity factors. Ambient UVR was assigned by linking geocoded residential locations, based on self-reported residential history information collected from the third questionnaire to satellite-based ambient UVR data from the National Aeronautics and Space Administration's Total Ozone Mapping Spectrometer database. To examine the association of reproductive factors, exogenous hormone use, and first primary invasive melanoma of the skin, we used Poisson regression to calculate rate ratios (RRs) and 95% likelihood-based CIs, adjusting for attained age, birth cohort, lifetime average annual ambient UVR, contraceptives and menopausal hormone therapy use. To address the effect modification of ambient UVR exposure and sun sensitivities on melanoma risk, we conducted likelihood-ratio tests for multiplicative interaction.

MAIN RESULTS AND THE ROLE OF CHANCE

Over a median follow-up time of 17.1 years, 0.95% of eligible participants had an incident first primary melanoma (n = 444). Higher melanoma incidence rates were observed in participants with older attained age, blue/green/gray eye color, blonde/red/auburn natural hair color at age 15, fair skin complexion, and higher UVR. We found an increased incidence rate of melanoma in women who experienced menarche at an earlier age (13, 12 and <12 years vs ≥14 years: RR = 1.48, 95% CI = 1.11-1.98; 1.19, 0.89-1.61; 1.26, 0.93-1.73), and in women with older age at first birth (25-29 and ≥30 years vs <25 years; 1.09, 0.86-1.39; 1.48, 1.12-1.95; P-value for trend = 0.006). However, no significant association was observed for other reproductive factors, and for all exogenous hormone use. The associations of melanoma incidence for most reproductive factors and exogenous hormone use were not modified by ambient UVR, eye color, natural hair color at age 15 and skin complexion. The exception was that natural hair color at age 15 modified the associations of melanoma for age at menarche (P-value for interaction = 0.004) and age at first birth among parous women (0.005). In participants with blonde/red/auburn natural hair color at age 15, we found increased risk of melanoma among women who experienced menarche at age 13, 12 and <12 years (vs ≥14 years: RR = 3.54, 95% CI = 1.98-6.90; 2.51, 1.37-4.98; 2.66, 1.41-5.36, respectively; P-value for trend = 0.10). However, the association between age at menarche and melanoma was null in participants with brown/black natural hair color at age 15.

LIMITATIONS, REASONS FOR CAUTION

Information on reproductive history and exogenous hormone use was self-reported. We did not have information on specific doses or formulations of exogenous hormone medications or breastfeeding.

WIDER IMPLICATIONS OF THE FINDINGS

Women residing in areas of high ambient UVR and those with blonde/red/auburn natural hair color may constitute an additional high-risk group in need of more frequent skin cancer screening. Identifying susceptible periods of exposure or factors that modify UVR susceptibility may aid in guiding more targeted guidelines for melanoma prevention.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the Intramural Research Program, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services. Authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.