Cigarette smoking and urinary estrogens

Tobacco industry influence on breast cancer research, policy and public opinion: scoping the Truth Tobacco Industry Documents

OBJECTIVE

Over the last 35 years, there has been growing evidence suggesting a relationship between tobacco use and breast cancer. The tobacco industry's role in shaping research, policy and public opinion about the relationship is unknown. This study's objective is to determine if the tobacco industry-funded Council for Tobacco Research (CTR) Records and the Tobacco Institute (TI) Records, housed in the Truth Tobacco Industry Document Archive, contain documents related to internal research about breast cancer and strategies to influence the science and public opinion about breast cancer causes.

METHODS

We applied the situational scoping method, in which community advocates and university researchers collaborate, to (1) identify external events considered by CTR or TI as a threat or opportunity to business interests; (2) select events for further analysis and (3) conduct social worlds/arenas mapping of industry responses to selected events.

RESULTS

The CTR and TI Records contained 19 719 documents with the search term 'breast cancer' ranging from the 1950s to 1998. We analysed nine events relevant to the aim of this research. CTR and TI responded to external threats, pointing out methodological problems in studies they perceived as threatening, or characterising lung cancer as misdiagnosed or metastasised breast cancer. They responded to external opportunities with promoting and funding research focusing on smoking's 'protective effects' over breast cancer, and breast cancer's genetic, hormonal and dietary causes.

CONCLUSION

The CTR and TI Records are a rich source of documents related to tobacco industry efforts to influence breast cancer research, policy and public opinion away from any aetiologic relationship between tobacco use and breast cancer.

Sex-related association between smoke exposure and gallstones in a US population: a cross-sectional study

BACKGROUND

Cholelithiasis are a condition that creates an economic and medical burden on society, and women are more susceptible to gallbladder stones. However, the effect of smoking on the development of gallstones remains controversial. No studies, to our knowledge, have discussed the association between smoke exposure and gallstones separately in men and women. We evaluated the association between smoking and gallstones in both sexes.

METHODS

We conducted a cross-sectional analysis using data obtained from the National Health and Nutrition Examination Survey from 2017 to March 2020. The analysis was limited to individuals aged ≥ 20 years with complete information available. Self-reported smoking status, serum cotinine concentration, and self-reported gallstones conditions were combined to analyze the association of gallstones with smoking and cotinine concentration.

RESULTS

Of the 6,982 participants, a total of 6.2% (212) men and 14.5% (512) women reported having gallstones. Logistic regression analysis showed smoking and high serum cotinine level were risk factors associated with gallstones among women, both in the model 1 (current smoker: odds ratio [OR] = 1.563, 95% confidence interval [CI] = 1.044-2.339, p = 0.032; former smoker: OR = 1.434, 95% CI = 1.116-1.842, p = 0.007; cotinine ≥ 3 ng/mL: OR = 1.800, 95% CI = 1.247-2.596, p = 0.005; and cotinine 0.05-2.99 ng/mL: OR = 1.640, 95% CI = 1.188-2.263, p = 0.005) and model 2 (current smoker: OR = 1.588, 95% CI = 1.015-2.483, p = 0.044; cotinine ≥ 3 ng/mL: OR = 1.825; 95% CI = 1.181-2.821, p = 0.011; and cotinine 0.05-2.99 ng/mL: OR = 1.509, 95% CI = 1.075-2.126, p = 0.022). However, the association was statistically insignificant in men. The subgroup analysis showed the robustness of the association.

CONCLUSIONS

This study indicates smoking and elevated serum cotinine levels may be risk factors associated with the development of gallstones. Notably, the associations were specifically observed among women. The findings suggest the significance of smoking in the incidence of gallstones, which may potentially provide insights for future research on strategies to prevent gallstones, particularly among women. The validation of these findings necessitates the conduction of large-scale, high-quality prospective studies.

Substance use and menopausal symptoms among people with and without HIV in the US, 2008-2020

OBJECTIVE

The aim of the study is to assess associations between substance use and menopausal symptoms among US people living with and without HIV in a longitudinal cohort.

METHODS

We analyzed self-reported menopausal symptoms and substance use from biannual Women's Interagency HIV Study (WIHS) visits from 2008-2020. Substance use since the last visit or lifetime cumulative use included tobacco, alcohol, marijuana, crack/cocaine, and opioids. Logistic regression quantified associations between each substance use and menopausal symptom frequency (vasomotor, mood, and musculoskeletal), adjusting for other substance use, HIV status, demographics, comorbidities, and trauma.

RESULTS

A total of 1,949 participants contributed early perimenopausal, late perimenopausal, or postmenopausal study visits. Across reproductive-aging stages, based on menstrual history, and among participants with and without HIV, participants reported frequent vasomotor (range 22-43%), mood (18-28%), and musculoskeletal (25-34%) symptoms. Many reported ever using tobacco (72%), heavy alcohol (75%), marijuana (73%), crack (50%), and opioids (31%). Current heavy alcohol use (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.10-1.37), cumulative marijuana use (OR: 1.15, 95% CI: 1.01-1.32), and cumulative tobacco use (OR: 1.06, 95% CI: 1.01-1.12) were associated with a higher frequency of vasomotor symptoms; current heavy alcohol use (OR: 1.20, 95% CI: 1.04-1.39) and current opioid use (OR: 1.13; 95% CI: 1.01-1.25) were associated with mood symptoms; and current opioid use (OR: 1.11, 95% CI: 1.00-1.23) was associated with musculoskeletal symptoms. All other associations were found to be null.

CONCLUSIONS

Current and prior substance use may independently affect symptoms experienced during the menopausal transition and may indicate potential to benefit from additional intervention and referral to menopause specialty care.

Factors affecting age at menopause and their relationship with ovarian reserve: a comprehensive review

OBJECTIVE

The aim of this article was to discuss all the factors affecting the age at menopause and their correlation with ovarian reserve.

MATERIALS AND METHODS

A narrative review of original articles was performed using PubMed until December 2023. The following keywords were used to generate the list of citations: 'menopause', 'ovarian reserve' 'oocytes quality and quantity', 'ovarian ageing'.

RESULTS

Menopause is the final step in the process of ovarian ageing and is influenced by the oocyte pool at birth. Conditions that accelerate follicle depletion during the reproductive lifespan lead to premature ovarian insufficiency (POI) and premature ovarian failure (POF), while a higher ovarian reserve is associated with a delayed time to menopause. Reproductive history, sociodemographic, lifestyle and iatrogenic factors may impact ovarian reserve and the age at menopause.

CONCLUSIONS

Some factors affecting the age at menopause are modifiable and the risks of early menopause may be preventable. We hypothesise that by addressing these modifiable factors we may also preserve ovarian reserve. However, further interventional studies are needed to evaluate the effects of the described strategies on ovarian reserve.

Tobacco or marijuana use and infertility: a committee opinion

In the United States, approximately 21% of adults report some form of tobacco use, although 18% report marijuana use. Although the negative impact of tobacco use in pregnancy is well documented, the impact of tobacco and marijuana on fertility and reproduction is less clear. This committee opinion reviews the potential deleterious effects of tobacco, nicotine, and marijuana use on conception, ovarian follicular dynamics, sperm parameters, gamete mutations, early pregnancy, and assisted reproductive technology outcomes. It also reviews the current status of tobacco smoking cessation strategies. This document replaces the 2018 American Society for Reproductive Medicine Practice Committee document entitled Smoking and Infertility: a committee opinion (Fertil Steril 2018).

European guidelines for the diagnosis, treatment and follow-up of breast lesions with uncertain malignant potential (B3 lesions) developed jointly by EUSOMA, EUSOBI, ESP (BWG) and ESSO

INTRODUCTION

Breast lesions of uncertain malignant potential (B3) include atypical ductal and lobular hyperplasias, lobular carcinoma in situ, flat epithelial atypia, papillary lesions, radial scars and fibroepithelial lesions as well as other rare miscellaneous lesions. They are challenging to categorise histologically, requiring specialist training and multidisciplinary input. They may coexist with in situ or invasive breast cancer (BC) and increase the risk of subsequent BC development. Management should focus on adequate classification and management whilst avoiding overtreatment. The aim of these guidelines is to provide updated information regarding the diagnosis and management of B3 lesions, according to updated literature review evidence.

METHODS

These guidelines provide practical recommendations which can be applied in clinical practice which include recommendation grade and level of evidence. All sections were written according to an updated literature review and discussed at a consensus meeting. Critical appraisal by the expert writing committee adhered to the 23 items in the international Appraisal of Guidelines, Research and Evaluation (AGREE) tool.

RESULTS

Recommendations for further management after core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB) diagnosis of a B3 lesion reported in this guideline, vary depending on the presence of atypia, size of lesion, sampling size, and patient preferences. After CNB or VAB, the option of vacuum-assisted excision or surgical excision should be evaluated by a multidisciplinary team and shared decision-making with the patient is crucial for personalizing further treatment. De-escalation of surgical intervention for B3 breast lesions is ongoing, and the inclusion of vacuum-assisted excision (VAE) will decrease the need for surgical intervention in further approaches. Communication with patients may be different according to histological diagnosis, presence or absence of atypia, or risk of upgrade due to discordant imaging. Written information resources to help patients understand these issues alongside with verbal communication is recommended. Lifestyle interventions have a significant impact on BC incidence so lifestyle interventions need to be suggested to women at increased BC risk as a result of a diagnosis of a B3 lesion.

CONCLUSIONS

These guidelines provide a state-of-the-art overview of the diagnosis, management and prognosis of B3 lesions in modern multidisciplinary breast practice.

What Is Known about Breast Cancer in Young Women?

Breast cancer (BC) is the second leading cause of cancer-related death in women under the age of 40 years worldwide. In addition, the incidence of breast cancer in young women (BCYW) has been rising. Young women are not the focus of screening programs and BC in younger women tends to be diagnosed in more advanced stages. Such patients have worse clinical outcomes and treatment complications compared to older patients. BCYW has been associated with distinct tumour biology that confers a worse prognosis, including poor tumour differentiation, increased Ki-67 expression, and more hormone-receptor negative tumours compared to women >50 years of age. Pathogenic variants in cancer predisposition genes such as BRCA1/2 are more common in early-onset BC compared to late-onset BC. Despite all these differences, BCYW remains poorly understood with a gap in research regarding the risk factors, diagnosis, prognosis, and treatment. Age-specific clinical characteristics or outcomes data for young women are lacking, and most of the standard treatments used in this subpopulation currently are derived from older patients. More age-specific clinical data and treatment options are required. In this review, we discuss the epidemiology, clinicopathologic characteristics, outcomes, treatments, and special considerations of breast cancer in young women. We also underline future directions and highlight areas that require more attention in future studies.

Acute nicotine exposure blocks aromatase in the limbic brain of healthy women: A [11C]cetrozole PET study

BACKGROUND

Of interest to women's mental health, a wealth of studies suggests sex differences in nicotine addiction and treatment response, but their psychoneuroendocrine underpinnings remain largely unknown. A pathway involving sex steroids could indeed be involved in the behavioural effects of nicotine, as it was found to inhibit aromatase in vitro and in vivo in rodents and non-human primates, respectively. Aromatase regulates the synthesis of oestrogens and, of relevance to addiction, is highly expressed in the limbic brain.

METHODS

The present study sought to investigate in vivo aromatase availability in relation to exposure to nicotine in healthy women. Structural magnetic resonance imaging and two [¹¹C]cetrozole positron emission tomography (PET) scans were performed to assess the availability of aromatase before and after administration of nicotine. Gonadal hormones and cotinine levels were measured. Given the region-specific expression of aromatase, a ROI-based approach was employed to assess changes in [¹¹C]cetrozole non-displaceable binding potential.

RESULTS

The highest availability of aromatase was found in the right and left thalamus. Upon nicotine exposure, [¹¹C]cetrozole binding in the thalamus was acutely decreased bilaterally (Cohen's d = -0.99). In line, cotinine levels were negatively associated with aromatase availability in the thalamus, although as non-significant trend.

CONCLUSIONS

These findings indicate acute blocking of aromatase availability by nicotine in the thalamic area. This suggests a new putative mechanism mediating the effects of nicotine on human behaviour, particularly relevant to sex differences in nicotine addiction.

A Systematic Review and Meta-Analysis of Smoking and Circulating Sex Hormone Levels Among Premenopausal Women

It is established that higher pre-diagnostic circulating androgen and estrogen levels are associated with increased breast cancer risk in premenopausal and postmenopausal women. Pooled analyses in postmenopausal women report higher androgen and estrogen levels in current heavy cigarette smokers compared to nonsmokers. However, evidence among premenopausal women has been inconsistent. We conducted a systematic review and meta-analysis to estimate differences in standardized mean hormone levels among current premenopausal smokers compared to nonsmokers. We reviewed and collated publications with sex hormone levels by smoking status among healthy, premenopausal women who were nonusers of exogenous hormones, including oral contraceptives, using PubMed through December 2019. A random effects meta-analysis was conducted to combine the standardized mean differences (SMD) and 95% confidence intervals (CIs) for estradiol, progesterone, testosterone, dehydroepiandrosterone, dehydroepiandrosterone-sulfate, and sex hormone-binding globulin by smoking status. Findings were summarized by menstrual cycle phase and overall. Nineteen published peer-reviewed articles were included. Significantly increased testosterone levels among smokers compared to nonsmokers were identified from cross-sectional studies with varied menstrual phase timing (SMD 0.14; 95% CI 0.0005, 0.29) and significantly increased dehydroepiandrosterone-sulfate levels were found over all phases (SMD 0.12; 95% CI 0.01, 0.22). However, substantial heterogeneity existed in these studies. This meta-analysis suggests that smoking may increase blood androgen levels in healthy premenopausal women which may increase breast cancer risk; however, the differences were modest. Larger and covariate-adjusted studies with standardized collection over the menstrual cycle are needed to better understand this relationship and to reduce heterogeneity. Implications: Existing research has described associations between high pre-diagnostic estradiol and androgen levels with breast cancer risk among premenopausal women and has established active smoking as a breast cancer risk factor. However, the smoking and circulating sex hormone associations among premenopausal women remain inadequately studied. In this meta-analysis, we identified an association between smoking and higher mean testosterone and dehydroepiandrosterone-sulfate levels with consideration of menstrual phase, providing additional information on smoking's potential pathway to premenopausal breast cancer.

Associations Between Smoking and Primary Sjögren Syndrome Classification Using the Sjögren's International Collaborative Clinical Alliance Cohort

OBJECTIVE

The objective of this study was to examine the association of smoking with Primary Sjögren syndrome (pSS) classification and pSS diagnostic test results. We hypothesized that past and current smokers would have lower odds of being classified as having Sjögren syndrome (SS) and lower odds of having abnormal individual SS diagnostic test results compared with nonsmokers.

METHODS

Participants with suspected or established pSS were enrolled into the Sjögren's International Collaborative Clinical Alliance (SICCA) registry and had oral, ocular, and rheumatologic examinations performed; blood and saliva samples collected; and labial salivary gland biopsy examinations performed; they also completed questionnaires at baseline. Logistic regression was used to determine whether smoking status was associated with pSS classification and individual pSS diagnostic test results.

RESULTS

A total of 3514 participants were enrolled in SICCA. A total of 1541 (52.9%) met classification criteria for pSS. Compared with never smokers, current smokers had reduced odds of being classified as having pSS, reduced odds of having a focus score ≥ 1 and serologic positivity for anti-SSA/anti-SSB antibodies, and lower odds of having abnormal signs or test results of dry eye disease. Compared with never smokers, past smokers did not have a statistically significant reduction in odds of being classified as having pSS and of having abnormal individual pSS diagnostic test results.

CONCLUSION

Compared with never smokers, current smokers in the SICCA cohort had lower odds of being classified as having pSS, lower odds of exhibiting abnormal signs and test results for dry eye disease, and lower odds of having a labial salivary gland biopsy supportive of pSS classification. Such negative associations, however, do not suggest that current smoking is of any benefit with respect to pSS.

Ginseng alleviates folliculogenesis disorders via induction of cell proliferation and downregulation of apoptotic markers in nicotine-treated mice

Background

Ginseng is a powerful phytoestrogen with high antioxidant properties.

Objective

This study aimed to evaluate the effect of Panax Ginseng (PG) on folliculogenesis, proliferation, and apoptosis in the ovary impaired by nicotine.

Methods

Forty adult mice were divided into five groups. Control, sham, and nicotine groups, and co-treated groups of nicotine and ginseng in doses of 0.5 and 1 g/kg. Folliculogenesis was assessed via histopathology and serum evaluation of estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) by ELISA. Lipid peroxidation and antioxidant enzyme activities both in homogenate tissue and serum were assayed by colorimetric analysis. Apoptotic markers of cytochrome c (Cyt c), Bax, and Bcl-2 were evaluated by RT-PCR. Proliferative index was studied by the Ki-67 immunostaining procedure.

Results

In comparison to the control or sham groups, nicotine significantly reduced the levels of FSH, LH, and estradiol hormones. An insignificant reduction was observed in the progesterone hormone. Nicotine reduced all healthy follicle numbers, except primordial (P = 0.001). Malondialdehyde (MDA) was increased in tissue and serum in the nicotine group (P = 0.01). Serum catalase (CAT) and enzymatic activity of superoxide dismutase (SOD) both were reduced in tissue and the serum, in the nicotine group. Nicotine induced a reduction in the proliferative indexes of granulosa and theca cells in pre-antral and antral follicles (P = 0.001). However, its effect on the proliferative index of stroma cells was not significant. Apoptotic markers were elevated in the nicotine group (P = 0.001). Co-treatment with ginseng elevated all sex hormones, increased healthy follicles, and reduced tissue or serum lipid peroxidation, compared with the nicotine group (p < 0.05). Co-Treatment with ginseng also reduced the expression of apoptotic markers and increased the proliferative indexes in granulosa and theca cells in pre-antral and antral follicles and also in stroma cells, in comparison to the nicotine group (P = 0.001). All above-mentioned alterations following treatment with ginseng were remarkable, especially in the dose of 1 g/kg.

Conclusion

This study showed ginseng protects folliculogenesis via alteration of hypothalamic- pituitary–gonadal (HPG) axis, induction of proliferation in ovarian somatic cells, reduction of lipid peroxidation, and downregulation of apoptotic markers in the mouse ovary, treated with nicotine.

Psychological aspects of infertility. A systematic review

Objective

Fertility may be defined as a capacity to conceive and produce offspring. Infertility is characterized by failure to establish a clinical pregnancy after 12 months of regular and unprotected sexual intercourse. Infertility concerns an estimated 8–12% of the global population, and is associated with factors including time of unwanted non-conception, age of female partner and number of diseases impacting fertility. Unexplained infertility is described as idiopathic. This study aimed to analyse and evaluate the influence of mental disorders, often considered as reasons for idiopathic infertility, on female and male fertility, including stress, depression, sleep and eating disorders, and addictions.

Methods

This systematic review comprised a search of MEDLINE, Cochrane and PubMed databases for relevant articles that were analysed by two independent reviewers.

Results

A total of 106 articles published between 1955–2019 were included. Mental disorders modify endocrine gland and immune system functioning at both the tissue and cellular level, and are negatively associated with female and male fertility.

Conclusion

Mental disorders may negatively impact female and male fertility. Further studies are required to explain the exact role and contribution of mental disorders to fertility.

A Review of Modifiable Risk Factors in Young Women for the Prevention of Breast Cancer

Breast cancer is the most common cancer diagnosis in women aged less than 40 years and the second most common cause of cancer death in this age group. Global rates of young onset breast cancer have risen steadily over the last twenty years. Although young women with breast cancer have a higher frequency of underlying pathogenic mutations in high penetrance breast cancer susceptibility genes (CSG) than older women, the vast majority of young breast cancer patients are not found to have a germline CSG mutation. There is therefore a need to inform young women regarding non-genetic breast cancer risk factors which have the potential to be influenced by changes in individual behaviour. A Pubmed search was performed using the search terms “young” or “early onset”, and “breast cancer” and “modifiable risk”. Titles and abstracts from peer-reviewed publications were screened for relevance. This review presents evidence for potentially modifiable risk factors of breast cancer risk in young women, including lifestyle factors (physical activity, body habitus, alcohol use, smoking, shift work and socioeconomic factors), reproductive and hormonal factors and iatrogenic risks. The extent to which these factors are truly modifiable is discussed and interactions between genetic and non-genetic risk factors are also addressed. Health care professionals have an opportunity to inform young women about breast health and risk when presenting at a “teachable moment”, including the benefits of physical activity and alcohol habits as risk factor. More focussed discussions regarding individual personal risk and benefit should accompany conversations regarding reproductive health and take into consideration both non-modifiable and iatrogenic BC risk factors.

Environmental exposures to endocrine disrupting chemicals (EDCs) and their role in endometriosis: a systematic literature review

PURPOSE

Endocrine-related diseases and disorders are on the rise globally. Synthetically produced environmental chemicals (endocrine-disrupting chemicals (EDCs)) mimic hormones like oestrogen and alter signalling pathways. Endometriosis is an oestrogen-dependent condition, affecting 10-15% of women of the reproductive age, and has substantial impacts on the quality of life. The aetiology of endometriosis is believed to be multifactorial, ranging from genetic causes to immunologic dysfunction due to environmental exposure to EDCs. Hence, we undertook a systematic review and investigated the epidemiological evidence for an association between EDCs and the development of endometriosis. We also aimed to assess studies on the relationship between body concentration of EDCs and the severity of endometriosis.

METHOD

Following PRISMA guidelines, a structured search of PubMed, Embase and Scopus was conducted (to July 2018). The included studies analysed the association between one or more EDCs and the prevalence of endometriosis. The types of EDCs, association and outcome, participant characteristics and confounding variables were extracted and analysed. Quality assessment was performed using standard criteria.

RESULTS

In total, 29 studies were included. Phthalate esters were positively associated with the prevalence of endometriosis. The majority (71%) of studies revealed a significant association between bisphenol A, organochlorinated environmental pollutants (dioxins, dioxin-like compounds, organochlorinated pesticides, polychlorinated biphenyls) and the prevalence of endometriosis. A positive association between copper, chromium and prevalence of endometriosis was demonstrated in one study only. Cadmium, lead and mercury were not associated with the prevalence of endometriosis. There were conflicting results for the association between nickel and endometriosis. The relationship of EDCs and severity of endometriosis was not established in the studies.

CONCLUSION

We found some evidence to suggest an association between phthalate esters, bisphenol A, organochlorinated environmental pollutants and the prevalence of endometriosis. Disentangling these exposures from various other factors that affect endometriosis is complex, but an important topic for further research.

Smoking and risk of surgical bleeding: nationwide analysis of 5,452,411 surgical cases

BACKGROUND

Although smoking is associated with several postoperative complications, a possible association with surgical bleeding remains unclear. We examined if smoking is associated with a higher risk of surgical bleeding.

STUDY DESIGN AND METHODS

We included patients from the American College of Surgeons National Surgical Quality Improvement Program 2007-2016 from 680 hospitals across the United States. Patients with information on age, sex, surgical specialty, and smoking status were included. Surgical bleeding was defined as 1 or more red blood cell (RBC) units transfused intraoperatively to 72 hours postoperatively. The association between smoking and surgical bleeding was examined using logistic regressions adjusted for age, sex, body mass index, ethnicity, comorbidities, laboratory values, American Society of Anesthesiologists score, type of anesthesia, duration of surgery, work relative value unit (surrogate for operative complexity), surgical specialty, and procedure year.

RESULTS

A total of 5,452,411 cases were recorded, of whom 19% smoked and 6% received transfusion. Odds ratios for transfusion were 1.06 (95% confidence interval [CI], 1.05-1.07) for smokers versus nonsmokers and 1.06 (95% CI, 1.04-1.09) for current smokers versus never-smokers. Odds ratios for cumulative smoking were 0.97 (95% CI, 0.95-1.00) for greater than 0 to 20 versus 0 pack-years, 1.04 (95% CI, 1.01-1.07) for greater than 20 to 40, and 1.12 (95% CI, 1.09-1.15) for greater than 40 (p for trend < 0.001). Hazard ratios for reoperations due to any cause and to bleeding were 1.28 (95% CI, 1.27-1.31) and 0.99 (95% CI, 0.93-1.04).

CONCLUSION

Smoking was associated with a higher risk of RBC transfusion as a proxy for surgical bleeding across all surgical specialties combined.

Factors associated with menstrual cycle irregularity and menopause

Background

A regular menstrual cycle is an important indicator of a healthy reproductive system. Previous studies reported obesity, stress, and smoking as the factors that are associated with irregular menstruation and early menopause. However, the integrative effects of these modifiable risk factors have not been fully understood. This study aimed to investigate the modifiable risk factors of menstrual cycle irregularity and premature menopause, as well as their individual and combined effects among adult women in Korea.

Method

This study selected adult women aged 19 years and above who had been included in the 2007–2014 Korean National Health and Nutrition Examination Survey. We used a separate dataset to analyze the risk factors of menstrual cycle irregularity and menopause (pre- and postmenopausal women: n = 4788 and n = 10,697, respectively). Univariate and multiple logistic regression analyses were conducted to evaluate the effects of smoking, drinking, obesity, and perceived level of stress on the menstrual cycle and menopause. Both logit and linear models were used in the analyses of the association between smoking and menopausal age. Equivalized household income, marital status, and educational level were considered as covariates. The modifiable risk factor scores were also calculated to integrate the effect of smoking, drinking, and obesity in the analysis.

Result

Results showed that smoking status, pack-year, obesity, and perceived level of stress were significantly associated with irregular menstruation among premenopausal women. Especially, women demonstrating > 3 modifiable risk factor scores had 1.7 times higher risk of having irregular menstruation than those who had a 0 score. Meanwhile, early initiation of smoking (≤19 years) and high pack-year (≥5) were also significantly associated with premature menopause among postmenopausal women.

Conclusion

This study demonstrated that modifiable risk factors, such as smoking, obesity, and stress, were significantly associated with menstrual cycle irregularity. Lifetime smoking was also correlated with early menopause. Our results suggested that healthier lifestyle practices, including, cessation of smoking, weight control, and stress management, were important factors in improving the reproductive health of women throughout life.

Epidemiology of uterine fibroids: a systematic review

Background

Uterine fibroids (UFs) are the most common neoplasm affecting women that can cause significant morbidity and may adversely impact fertility.

Objectives

To examine UF epidemiology and to evaluate the relative strengths of putative risk factors.

Search strategy

MEDLINE and Embase were searched for studies published in English between January 1995 and April 2015.

Selection criteria

Publications reporting relevant data from registries and other observational studies with over 1000 patients and single‐centre studies with over 100 patients were selected.

Data collection and analysis

Data on UF incidence, prevalence and associated risk factors were extracted from 60 publications.

Main results

Wide ranges were reported in both UF incidence (217–3745 cases per 100 000 women‐years) and prevalence (4.5–68.6%), depending on study populations and diagnostic methods. Black race was the only factor that was recurrently reported to increase UF risk, by two–threefold compared with white race. Eleven other factors affected UF risk to a magnitude similar to or greater than race. Age, premenopausal state, hypertension, family history, time since last birth, and food additive and soybean milk consumption increased UF risk; use of oral contraceptives or the injectable contraceptive depot medroxyprogesterone acetate, smoking in women with low body mass index and parity reduced UF risk.

Conclusions

We identified 12 risk factors that play an important role in UF epidemiology. The UF risk factor with the strongest evidence is black race. High‐quality prospective observational data are needed to improve our understanding of UF epidemiology, and thus its aetiology and optimal management.

Tweetable abstract

Uterine fibroids occur in about 70% of women. Black race and 11 other factors affect uterine fibroid risk.

Ovotoxicity of cigarette smoke: A systematic review of the literature

This study reviews the scientific literature on the noxious effects of cigarette smoke on the ovarian follicle, and the cumulative data on the impact of smoking on in vitro fertilization (IVF) cycle outcome. There is a close association between tobacco smoke and accelerated follicle loss, abnormal follicle growth and impairment of oocyte morphology and maturation. There is an increasing amount of evidence indicating that smoke can directly derange folliculogenesis. Increased cellular apoptosis or autophagy, DNA damage and abnormal crosstalk between oocyte and granulosa cells have been implicated in the demise of ovarian follicles. It becomes increasingly clear that maternal smoking can exert multigenerational effects on the ovarian function of the progeny. Growing evidence suggests that cigarette smoke is associated with decreased results after IVF. Further research is needed to better define the molecular mechanisms behind smoking-induced ovarian disruption.

UPLC-MS/MS method for the determination of tobacco-specific biomarker NNAL, tamoxifen and its main metabolites in rat plasma

Cigarette smoke is known to interact with tamoxifen-metabolizing enzymes and transporters and potentially affect its treatment outcome. 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanol (NNAL) is an important metabolite of 4-(methylnitro-samino)-1-(3-pyridyl)-1-butanone (NNK) because it is frequently used as a biomarker to assess human smoke exposure. In order to study the potential pharmacokinetic interaction between cigarette smoke and tamoxifen in rats a UPLC-MS/MS method for the simultaneous determination of NNAL and tamoxifen along with its metabolites in rat plasma has been developed and validated. Analytes were extracted with methanol and separated on a HSS T3 column by a gradient elution with the mobile phase consisting of acetonitrile and water. The lower limits of quantitation ranged from 0.05 to 0.62 ng/mL. Precisions showed RSD <15.8% and accuracy in the range 80.6-116.0%. Mean analyte recoveries ranged from 76.9 to 108.4%. The method was successfully applied to study the effects of cigarette smoke condensate (CSC), NNK and benzo(a)pyrene pre-treatment on the pharmacokinetics of tamoxifen and its metabolites in rats. Significant effects of CSC, NNK, benzo(a)pyrene were observed on pharmacokinetics of tamoxifen and its metabolites. We also found that plasma NNAL levels are statistically significant correlated with plasma 4-hydroxy-tamoxifen and endoxifen.

Risk factors for hot flashes among women undergoing the menopausal transition: baseline results from the Midlife Women's Health Study

OBJECTIVE

The aim of this study was to examine the associations of demographic characteristics, health behaviors, and hormone concentrations with the experience of any, current, more severe, and more frequent midlife hot flashes.

METHODS

Baseline data from 732 women aged 45 to 54 years who were enrolled in the Midlife Women's Health Study were analyzed. A clinic visit was conducted to collect blood samples for hormone assays and to measure ovarian volume using transvaginal ultrasound. A self-administered questionnaire ascertained information on demographic factors, health habits, and hot flash history. Multivariable logistic regression was conducted to examine associations between potential risk factors and hot flash outcomes.

RESULTS

Approximately 45% of participants reported experiencing midlife hot flashes. In covariate-adjusted models, older age, perimenopause status, current and past cigarette smoking, and depressive symptoms were significantly associated with increased odds of all of the hot flash outcomes. In addition, history of oral contraceptive use was associated with increased odds of any hot flashes. In contrast, higher current alcohol intake was significantly associated with decreased odds of any, current, and more severe hot flashes. Higher estradiol and progesterone concentrations were significantly associated with decreased odds of all hot flash outcomes.

CONCLUSIONS

Although the temporality of such associations is not known because of the cross-sectional nature of the data, these observed relationships can help to identify women at risk for hot flashes.

Life course exposure to smoke and early menopause and menopausal transition

OBJECTIVE

Early age at menopause is associated with increased risk of cardiovascular disease, stroke, osteoporosis, and all-cause mortality. Cigarette smoke exposure in adulthood is an established risk factor for earlier age at natural menopause and may be related to age at the menopausal transition. Using data from two US birth cohorts, we examined the association between smoke exposure at various stages of the life course (prenatal exposure, childhood exposure to parental smoking, and adult smoke exposure) and menopause status in 1,001 women aged 39 to 49 years at follow-up.

METHODS

We used logistic regression analysis (adjusting for age at follow-up) to estimate odds ratios (ORs) and 95% confidence intervals (CI) relating smoke exposure to natural menopause and the menopausal transition.

RESULTS

The magnitudes of the associations for natural menopause were similar but not statistically significant after adjustment for confounders among (i) women with prenatal smoke exposure who did not smoke on adult follow-up (OR, 2.7; 95% CI, 0.8-9.4) and (ii) current adult smokers who were not exposed prenatally (OR, 2.8; 95% CI, 0.9-9.0). Women who had been exposed to prenatal smoke and were current smokers had three times the risk of experiencing earlier natural menopause (adjusted OR, 3.4; 95% CI, 1.1-10.3) compared with women without smoke exposure in either period. Only current smoking of long duration (>26 y) was associated with the timing of the menopausal transition.

CONCLUSIONS

Our data suggest that exposure to smoke both prenatally and around the time of menopause accelerates ovarian aging.

Effect of lifestyle and reproductive factors on the onset of breast cancer in female BRCA 1 and 2 mutation carriers

BACKGROUND

The birth year-dependent onset of breast cancer (BC) in BRCA1/2 mutation carriers suggests a risk-modifying role for reproductive and life style factors. We therefore examined possible associations between these factors and age at diagnosis.

METHODS

Cox regression analysis and log-Rank testing were used to estimate the effect of potential life style factors on the onset of BC in 197 BRCA mutation carriers.

RESULTS

Nulliparous BRCA mutation carriers developed BC earlier than those who had delivered (36.4 vs. 40.9; P = 0.001). Similarly, smokers and women who had used oral contraceptives experienced an earlier cancer onset (39.0 vs. 41.4; P = 0.05 and 39.3 vs. 44.9; P = 0.0001, respectively). In multivariate analysis, oral contraceptive use (HR: 1.7; P = 0.006) and birth cohort (< vs. ≥1965 HR: 4.5; P = 0.001) were associated with an earlier BC onset, while previous pregnancies led to a delay (HR: 0.2; P = 0.04). Mutation carriers born ≥1965 were less likely to have experienced pregnancies and more likely to have used oral contraceptives, and consequently developed BC at an earlier age (median age: 42 vs. 58; P < 0.0001 log-Rank test).

CONCLUSION

We here demonstrate that in BRCA1/2 mutation carriers the birth cohort-associated differences in the onset of BC are profound and influenced by reproductive factors.

Passive Smoking and Breast Cancer Risk among Non-Smoking Women: A Case-Control Study in China

BACKGROUND

The role of passive smoking on breast cancer risk was unclear. This study aimed to evaluate the association between passive smoking and breast cancer risk among Chinese women.

METHODS/PRINCIPAL FINDINGS

A hospital-based case-control study, including 877 breast cancer cases and 890 controls, frequency-matched by age and residence, was conducted. A structured questionnaire was used to collect information on passive smoking history through face-to-face interview by trained interviewers. Unconditional logistic regression models were used to estimate the association between passive smoking and breast cancer risk. A positive association between any passive smoking exposure and breast cancer risk was observed. Compared with women who were never exposed to passive smoking, women who were ever exposed had a higher breast cancer risk, with the adjusted odds ratio (OR) and 95% confidence interval (CI) of 1.35 (1.11-1.65). Similar result was found on home passive smoking exposure and breast cancer risk, but not on workplace passive smoking exposure. Women who were ever exposed to tobacco smoke at home had a higher risk of breast cancer compared with never exposed women, with the adjusted OR (95% CI) of 1.30 (1.05-1.61). Home passive smoking exposure showed significant dose-response relationships with breast cancer risk in smoker-years, cigarettes/day and total pack-years (Ptrend=0.003, 0.006 and 0.009, respectively). An increased total smoker-years of any passive exposure significantly elevated the risk of breast cancer (Ptrend<0.001). Positive associations and dose-response relationships were found among postmenopausal women and all subtypes of estrogen receptor (ER) and progesterone receptor (PR) status of breast cancer.

CONCLUSIONS

Passive smoking was associated with an increased risk of breast cancer among non-smoking Chinese women. A stronger positive association with breast cancer risk was seen mainly among postmenopausal women.

Air pollution and risk of uterine leiomyomata

BACKGROUND

Air pollution, particularly from vehicle exhaust, has been shown to influence hormonal activity. However, it is unknown whether air pollution exposure is associated with the occurrence of uterine leiomyomata, a hormonally sensitive tumor of the uterus.

METHODS

For 85,251 women 25-42 years of age at enrollment in the Nurses' Health Study II, we examined proximity to major roadways and outdoor levels of particulate matter less than 10 microns (PM10) or 2.5 microns (PM2.5) or between 10 and 2.5 microns (PM10-2.5) in diameter for all residential addresses from September 1989 to May 2007. To be eligible for this analysis, a woman had to be alive and respond to questionnaires, premenopausal with an intact uterus, and without diagnoses of cancer or prevalent uterine leiomyomata. Incidence of ultrasound- or hysterectomy-confirmed uterine leiomyomata and covariates were reported on biennial questionnaires sent through May 2007. Multivariable time-varying Cox proportional hazard models were used to estimate the relationship between distance to road or PM exposures and uterine leiomyomata risk.

RESULTS

During 837,573 person-years of follow-up, there were 7760 incident cases of uterine leiomyomata. Living close to a major road and exposures to PM10 or PM10-2.5 were not associated with an increased risk of uterine leiomyomata. However, each 10 μg/m increase in 2-year average, 4-year average, or cumulative average PM2.5 was associated with an adjusted hazard ratio of 1.08 (95% confidence interval = 1.00-1.17), 1.09 (0.99-1.19), and 1.11 (1.03-1.19), respectively.

CONCLUSIONS

Chronic exposure to PM2.5 may be associated with a modest increased risk of uterine leiomyomata.

Long-term exposure to air pollution and mammographic density in the Danish Diet, Cancer and Health cohort

BACKGROUND

Growing evidence suggests that air pollution may be a risk factor for breast cancer, but the biological mechanism remains unknown. High mammographic density (MD) is one of the strongest predictors and biomarkers of breast cancer risk, but it has yet to be linked to air pollution. We investigated the association between long-term exposure to traffic-related air pollution and MD in a prospective cohort of women 50 years and older.

METHODS

For the 4,769 women (3,930 postmenopausal) participants in the Danish Diet, Cancer and Health cohort (1993-1997) who attended mammographic screening in Copenhagen (1993-2001), we used MD assessed at the first screening after cohort entry. MD was defined as mixed/dense or fatty. Traffic-related air pollution at residence was assessed by modeled levels of nitrogen oxides (NOx) and nitrogen dioxide (NO2). The association between mean NOx and NO2 levels since 1971 until cohort baseline (1993-97) and MD was analyzed using logistic regression, adjusting for confounders, and separately by menopause, smoking status, and obesity.

RESULTS

We found inverse, statistically borderline significant associations between long-term exposure to air pollution and having mixed/dense MD in our fully adjusted model (OR; 95% CI: 0.96; 0.93-1.01 per 20 μg/m(3) of NOx and 0.89; 0.80- 0.98 per 10 μg/m(3) of NO2). There was no interaction with menopause, smoking, or obesity.

CONCLUSION

Traffic-related air pollution exposure does not increase MD, indicating that if air pollution increases breast cancer risk, it is not via MD.

Tobacco and alcohol in relation to male breast cancer: an analysis of the male breast cancer pooling project consortium

BACKGROUND

The etiology of male breast cancer is poorly understood, partly due to its relative rarity. Although tobacco and alcohol exposures are known carcinogens, their association with male breast cancer risk remains ill-defined.

METHODS

The Male Breast Cancer Pooling Project consortium provided 2,378 cases and 51,959 controls for analysis from 10 case-control and 10 cohort studies. Individual participant data were harmonized and pooled. Unconditional logistic regression was used to estimate study design-specific (case-control/cohort) ORs and 95% confidence intervals (CI), which were then combined using fixed-effects meta-analysis.

RESULTS

Cigarette smoking status, smoking pack-years, duration, intensity, and age at initiation were not associated with male breast cancer risk. Relations with cigar and pipe smoking, tobacco chewing, and snuff use were also null. Recent alcohol consumption and average grams of alcohol consumed per day were also not associated with risk; only one subanalysis of very high recent alcohol consumption (>60 g/day) was tentatively associated with male breast cancer (ORunexposed referent = 1.29; 95% CI, 0.97-1.71; OR>0-<7 g/day referent = 1.36; 95% CI, 1.04-1.77). Specific alcoholic beverage types were not associated with male breast cancer. Relations were not altered when stratified by age or body mass index.

CONCLUSIONS

In this analysis of the Male Breast Cancer Pooling Project, we found little evidence that tobacco and alcohol exposures were associated with risk of male breast cancer.

IMPACT

Tobacco and alcohol do not appear to be carcinogenic for male breast cancer. Future studies should aim to assess these exposures in relation to subtypes of male breast cancer.

New exposure biomarkers as tools for breast cancer epidemiology, biomonitoring, and prevention: a systematic approach based on animal evidence

BACKGROUND

Exposure to chemicals that cause rodent mammary gland tumors is common, but few studies have evaluated potential breast cancer risks of these chemicals in humans.

OBJECTIVE

The goal of this review was to identify and bring together the needed tools to facilitate the measurement of biomarkers of exposure to potential breast carcinogens in breast cancer studies and biomonitoring.

METHODS

We conducted a structured literature search to identify measurement methods for exposure biomarkers for 102 chemicals that cause rodent mammary tumors. To evaluate concordance, we compared human and animal evidence for agents identified as plausibly linked to breast cancer in major reviews. To facilitate future application of exposure biomarkers, we compiled information about relevant cohort studies.

RESULTS

Exposure biomarkers have been developed for nearly three-quarters of these rodent mammary carcinogens. Analytical methods have been published for 73 of the chemicals. Some of the remaining chemicals could be measured using modified versions of existing methods for related chemicals. In humans, biomarkers of exposure have been measured for 62 chemicals, and for 45 in a nonoccupationally exposed population. The Centers for Disease Control and Prevention has measured 23 in the U.S. population. Seventy-five of the rodent mammary carcinogens fall into 17 groups, based on exposure potential, carcinogenicity, and structural similarity. Carcinogenicity in humans and rodents is generally consistent, although comparisons are limited because few agents have been studied in humans. We identified 44 cohort studies, with a total of > 3.5 million women enrolled, that have recorded breast cancer incidence and stored biological samples.

CONCLUSIONS

Exposure measurement methods and cohort study resources are available to expand biomonitoring and epidemiology related to breast cancer etiology and prevention.

Prenatal smoke exposure and mammographic density in mid-life

Tobacco smoke has both carcinogenic effects and anti-estrogenic properties and its inconsistent association with breast cancer risk in observational studies may be because of these competing effects across the lifecourse. We conducted a prospective study of prenatal smoke exposure, childhood household smoke exposure, and adult active smoke exposure and mammographic density, a strong intermediate marker of breast cancer risk, in an adult follow-up of existing US birth cohorts. Specifically, we followed up women who were born between 1959 and 1967 and whose mothers participated in either the Collaborative Perinatal Project (Boston and Providence sites) or the Childhood Health and Development Study in California. Of the 1134 women interviewed in adulthood (ranging in age from 39 to 49 years at interview), 79% had a screening mammogram. Cigarette smoking was reported by mothers at the time of their pregnancy; 40% of mothers smoked while pregnant. Women whose mothers smoked during pregnancy had a 3.1% (95% confidence interval (CI) = -6.0%, -0.2%) lower mammographic density than women whose mothers did not smoke during pregnancy. When we further accounted for adult body mass index and adult smoking status, the association remained (β = -2.7, 95% CI = -5.0, -0.3). When we examined patterns of smoking, prenatal smoke exposure without adult smoke exposure was associated with a 5.6% decrease in mammographic density (β = -5.6, 95% CI = -9.6, -1.6). Given the strength of mammographic density as an intermediate marker for breast cancer, the inverse associations between mammographic density and smoking patterns across the lifecourse may help explain the complex association between cigarette smoking and breast cancer risk.

Pre- and postoperative alcohol consumption in breast cancer patients: impact on early events

Purpose

To investigate the association between pre- and postoperative alcohol consumption and risk for early breast cancer events, since the association between alcohol consumption and prognosis in breast cancer patients is unclear.

Methods

Alcohol consumption was recorded for 934 primary breast cancer patients who underwent breast cancer surgery in Lund, Sweden, between 2002 and 2011 and were followed until December 31^st 2012. Clinical data were obtained from medical records and population registries. Pre- and postoperative alcohol consumption was analyzed in relation to risk for early events.

Results

Median follow-up time was 3.03 years and 100 breast cancer events, 65 distant metastases, and 76 deaths occurred. Compared to no consumption, any preoperative alcohol consumption was weakly associated with lower risk for early events, adjusted HR 0.69 (0.45-1.04), distant metastases, 0.60 (0.36-1.00) and death, 0.62 (0.38-1.01). In the 572 patients without axillary lymph node involvement, any alcohol consumption was not associated with risk for early events. However, in the 360 patients with axillary lymph node involvement, preoperative alcohol consumption was associated with lower risk for early events (adjusted HR 0.43 0.24-0.77; P_interaction = 0.01).

Conclusion

Pre- and postoperative alcohol consumption was weakly associated with lower risk for early breast cancer events. The data does not support recommending that all breast cancer patients abstain from low to moderate alcohol consumption.

Hot flashes and blood pressure in middle-aged Japanese women

BACKGROUND

Some Western studies have reported that hot flashes are risk factors of cardiovascular diseases. We aimed to investigate the association between hot flashes and blood pressure in middle-aged Japanese women.

METHODS

Annual medical checkup data from 1,058 healthy middle-aged Japanese women were analyzed. Nonstandardized coefficients (B), which were calculated by multiple linear regression analysis, were used to evaluate differences in blood pressure resulting from hot flashes.

RESULTS

The prevalence of current hot flashes was 20.2%, and the experience of hot flashes was significantly more frequent according to age (P < 0.01). Systolic blood pressure was significantly higher in women currently experiencing hot flashes and in those experiencing them within the previous month than in those without such experience (B = 6.0, P < 0.01; B = 3.7, P < 0.05, respectively). Diastolic blood pressure was significantly higher in women currently experiencing hot flashes than in those without such experience (B = 3.9; P < 0.01). Among current smokers, systolic blood pressure was 16.4mm Hg higher in those currently experiencing hot flashes (P < 0.01), but this difference was less among nonsmokers (P < 0.05). In addition, pulse pressure was 10.5mm Hg higher in current smokers currently experiencing hot flashes than in other current smokers (P < 0.01), but not among nonsmokers.

CONCLUSIONS

In middle-aged Japanese women, hot flashes were associated with higher pulse pressure among smokers but not among nonsmokers.

Risk factors for night sweats and hot flushes in midlife: results from a prospective cohort study

OBJECTIVE

This study aims to identify social, lifestyle, and reproductive history risk factors for night sweats (NS) only, hot flushes (HF) only, and both NS and HF.

METHODS

Risk factors and symptoms among 10,454 participants of the Australian Longitudinal Study on Women's Health who were aged 45 to 50 years in 1996 were measured at baseline and 3-year intervals (surveys 2-6) for 15 years. Multinomial logistic regression analyses were performed.

RESULTS

Compared with neither symptom, both symptoms together were reported less often by highly educated women (odds ratio, 0.61; 99.9% CI, 0.50-0.74), but more often by women who were heavier (odds ratio, 1.23; 99.9% CI, 1.08-1.40), were current smokers (odds ratio, 1.31; 99.9% CI, 1.09-1.56), were high-risk drinkers (odds ratio, 1.44; 99.9% CI, 1.10-1.89), were perimenopausal (odds ratio, 6.57; 99.9% CI, 5.52-7.82) or postmenopausal (odds ratio, 4.74; 99.9% CI, 4.00-5.63), had gained weight (odds ratio, 1.15; 99.9% CI, 1.01-1.31), or had premenstrual tension (odds ratio, 1.86; 99.9% CI, 1.48-2.34), than by women without these characteristics. HF only was reported less often by highly educated women (odds ratio, 0.73; 99.9% CI, 0.59-0.90), but more often by perimenopausal (odds ratio, 3.58; 99.9% CI, 2.95-4.35) or postmenopausal (odds ratio, 2.97; 99.9% CI, 2.47-3.57) women and by those with premenstrual tension (odds ratio, 1.60; 99.9% CI, 1.25-2.04). Finally, NS only was reported more often among current smokers (odds ratio, 1.55; 99.9% CI, 1.11-2.19), high-risk drinkers (odds ratio, 1.76; 99.9% CI, 1.04-2.97), perimenopausal women (odds ratio, 1.53; 99.9% CI, 1.14-2.06), those with diabetes (odds ratio, 1.91; 99.9% CI, 1.08-3.35), those with premenstrual tension (odds ratio, 1.67; 99.9% CI, 1.09-2.56), or those of early age at first pregnancy (odds ratio, 1.45; 99.9% CI, 1.05-1.99).

CONCLUSIONS

The presence of both symptoms is associated with social, behavioral, and menstrual factors. Some differences in risk factors among women who report only one symptom or both symptoms are observed, suggesting a slightly different etiology for each.

Cigarette smoking and breast cancer risk in relation to joint estrogen and progesterone receptor status: a case-control study in Japan

An association of cigarette smoking with breast cancer risk has been hypothesized. However, results from previous studies have been inconsistent. This case-control study investigated the association of cigarette smoking with breast cancer risk in terms of estrogen-receptor/progesterone-receptor (ER/PgR) status. From among female patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2011, 1,263 breast cancer cases (672 ER+/PgR+, 158 ER+/PgR-, 22 ER-/PgR+, 308 ER-/PgR- and 103 missing) and 3,160 controls were selected. History of smoking (ever, never), some smoking-related measures, and passive smoking from husbands (ever, never) were assessed using a self-administered questionnaire. Polytomous logistic regression and tests for heterogeneity across ER+/PgR + and ER-/PgR- were conducted. For any hormone receptor subtype, no significant association was observed between history of smoking (ever, never) and breast cancer risk. Analysis of smoking-related measures revealed that starting to smoke at an early age of ≤19 years was significantly associated with an increased risk of postmenopausal ER-/PgR- cancer (odds ratio = 7.01, 95% confidence interval: 2.07-23.73). Other measures of smoking such as the number of cigarettes per day, the duration of smoking, and start of smoking before the first birth were not associated with breast cancer risk for any receptor subtype. There was no association between passive smoking (ever, never) and breast cancer risk for any of the four subtypes. These results indicate that history of smoking and passive smoking from husbands may have no overall effect on breast cancer risk for any hormone receptor subtype. However, it is possible that women who start to smoke as teenagers may have a higher risk of developing postmenopausal ER-/PgR- cancer. Further studies are needed to clarify the association of smoking with breast cancer risk, especially the role of starting to smoke at an early age.

Cigarette smoking and endometrial carcinoma risk: the role of effect modification and tumor heterogeneity

PURPOSE

The inverse relationship between cigarette smoking and endometrial carcinoma risk is well established. We examined effect modification of this relationship and associations with tumor characteristics in the National Institutes of Health-AARP Diet and Health Study.

METHODS

We examined the association between cigarette smoking and endometrial carcinoma risk among 110,304 women. During 1,029,041 person years of follow-up, we identified 1,476 incident endometrial carcinoma cases. Multivariable Cox proportional hazards regression models were used to estimate relative risks (RRs) and 95 % confidence intervals (CIs) for the association between smoking status, years since smoking cessation, and endometrial carcinoma risk overall and within strata of endometrial carcinoma risk factors. Effect modification was assessed using likelihood ratio test statistics. Smoking associations by histologic subtype/grade and stage at diagnosis were also evaluated.

RESULTS

Reduced endometrial carcinoma risk was evident among former (RR 0.89, 95 % CI 0.80, 1.00) and current (RR 0.65, 95 % CI 0.55, 0.78) smokers compared with never smokers. Smoking cessation 1-4 years prior to baseline was significantly associated with endometrial carcinoma risk (RR 0.65, 95 % CI 0.48, 0.89), while cessation ≥ 10 years before baseline was not. The association between smoking and endometrial carcinoma risk was not significantly modified by any endometrial carcinoma risk factor, nor did we observe major differences in risk associations by tumor characteristics.

CONCLUSION

The cigarette smoking-endometrial carcinoma risk relationship was consistent within strata of important endometrial carcinoma risk factors and by clinically relevant tumor characteristics.

TNBC vs. Non-TNBC: A Five-Year Retrospective Review of Differences in Mean Age, Family History, Smoking History and Stage at Diagnosis at an Inner City University Program

BACKGROUND

In recent years, breast cancer has been classified on the basis of estrogen or progesterone receptor (ER/PR) status and whether the human epidermal growth factor 2 receptor (HER2/neu) protein is overexpressed. Based on this system, breast cancer is broadly divided into the triple negative breast cancer (TNBC) and the non-TNBC subtypes. TNBC is a subtype of breast cancer, notable for its propensity to metastasize early and display a comparatively more aggressive course than its non-TNBC counterpart. Certain clinico-pathologic and demographic risk factors have been associated with breast cancer. In this study, we aim to compare mean age, ethnicity, family history, tobacco use and stage at presentation between TNBC and non-TNBC subtypes at our inner city university program.

METHODS

We reviewed data in our tumor registry between January 2000 and December 2005 with particular attention to mean age, race, family history, tobacco use and stage at presentation. We found a total of 445 patients with various subtypes of breast cancers. We included only those patients in whom the status of both ER/PR and the status of Her2/neu protein overexpression were recorded. Our strict selection criteria lead to an exclusion of about 103 patients. Out of the remaining 342 patients, 39 were TNBC and 303 were non-TNBC.

RESULTS

Mean age of onset for TNBC vs. non-TNBC patients was 59.87 ± 15.67 years vs. 60.09 ± 13.98 years respectively (P = 0.9272). In terms of ethnicity, TNBC vs. non-TNBC patients had the following racial backgrounds: black, 58.97% vs. 39.27%; white, 35.90% vs. 57.76%; Chinese, 2.56% vs. 0.99%; others, 2.57% vs. 1.98% respectively (P = 0.004, OR = 2.755). Comparisons with respect to a history of tobacco abuse for TNBC vs. non-TNBC patients revealed a positive smoking history in 20.51% vs. 27.72% whereas there was no former or current smoking history in 71.79% vs. 61.72% respectively (P = 0.4385). Comparison of family history of a breast cancer in TNBC vs. non-TNBC patients showed that positive family history of breast cancer was seen in 30.77% vs. 33.33%, no family history of cancer was seen in 51.28% vs. 51.82% and unknown 17.95% vs. 14.85% (P = 0.8384). Pathologic stage at the time of diagnosis for TNBC vs. non-TNBC patients was as follows: stage 0, 15.79% vs. 11.37% (P = 0.4332); stage 1, 34.21% vs. 30.98% (P = 0.6890); stage 2, 28.98% vs. 37.25% (P = 0.3205); stage 3, 18.42% vs. 17.25% (P = 0.0.8591); and stage 4, 3.63% vs. 3.14% (P = 0.8651). Analysis using Chi-square test revealed χ2 value of 0.855.

CONCLUSION

Our results add to the growing body of evidence pertaining to the association of certain demographic and clinico-pathologic characteristics in women with breast cancer. We found that in our patient population, there is a significant ethnic predisposition for the two types of breast cancers that we studied. African Americans were more likely to have TNBC compared to the higher frequency of non-TNBC in white females. We did not find a significant difference in mean age, cigarette smoking, family history and stage at diagnosis between the TNBC and non-TNBC breast cancer patients. These findings are all consistent with the previously published research studies.

Reproductive factors, exogenous hormones, and pancreatic cancer risk in the CTS

Female steroid hormones are hypothesized to play a protective role in pancreatic cancer risk. However, results from epidemiologic studies that examined hormone-related exposures have been inconsistent. The California Teachers Study is a cohort study of female public school professionals that was established in 1995-1996. Of the 118,164 eligible study participants, 323 women were diagnosed with incident invasive pancreatic cancer through December 31, 2009. Multivariable Cox proportional hazards regression methods were used to estimate hazard ratios and 95% confidence intervals for the association of pancreatic cancer risk with reproductive factors and exogenous hormone use. Current users of estrogen-only therapy at baseline (1995-1996) had a lower risk of pancreatic cancer than did participants who had never used hormone therapy (hazard ratio = 0.59, 95% confidence interval: 0.42, 0.84). Use of estrogen-plus-progestin therapy was not associated with the risk of pancreatic cancer. A longer duration of oral contraceptive use (≥10 years of use compared with never use) was associated with an increased risk of cancer (hazard ratio = 1.72, 95% confidence interval: 1.19, 2.49). Reproductive factors, including age at menarche, parity, breastfeeding, and age at menopause, were not associated with pancreatic cancer risk. Our results suggest that increased estrogen exposure through estrogen-only therapy may reduce pancreatic cancer risk in women.

Lack of an association between passive smoking and incidence of female breast cancer in non-smokers: evidence from 10 prospective cohort studies

BACKGROUND

Several case-control studies have suggested that passive smoking may increase the incidence of female breast cancer. However, the results of cohort studies have been inconsistent in establishing an association. The present study evaluated the association between passive smoking and incidence of female breast cancer through a meta-analysis of prospective cohort studies.

METHODS

Relevant articles published before August 2012 were identified by searching the electronic databases PubMed, Embase, and Web of Science. Pooled relative risks (RRs) were determined with either a fixed or random effects model and were used to assess the strength of the association. Sensitivity and subgroup analyses according to ethnicity, menopausal status, and the period and place of exposure to passive smoking were also performed.

RESULTS

Ten prospective cohort studies involving 782 534 female non-smokers were included in the meta-analysis and 14 831 breast cancer cases were detected. Compared with the women without exposure to passive smoking, the overall combined RR of breast cancer was 1.01 (95% confidence interval: 0.96 to 1.06, P = 0.73) among women with exposure to passive smoking. Similar results were achieved through the subgroup analyses. No evidence of publication bias was observed.

CONCLUSION

The results suggest that passive smoking may not be associated with increased incidence of breast cancer. However, the present conclusion should be considered carefully and confirmed with further studies.

Increased long-term recreational physical activity is associated with older age at natural menopause among heavy smokers: the California Teachers Study

OBJECTIVE

Although physical activity modulates the hypothalamic-pituitary-ovarian axis, the few studies that have investigated whether physical activity is associated with age at natural menopause have yielded mixed results. We set out to determine whether physical activity is associated with the timing of natural menopause in a large cohort of California women overall and by smoking history.

METHODS

We investigated the association between long-term physical activity (h/wk/y) and age at natural menopause among 97,945 women in the California Teachers Study. Multivariable Cox proportional hazards regression methods were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). The impact of cigarette smoking (never smoker, former light smoker, former heavy smoker, current light smoker, and current heavy smoker) as an effect modifier was evaluated.

RESULTS

In a multivariable model adjusted for body mass index at age 18 years, age at menarche, race/ethnicity, and age at first full-term pregnancy, increased physical activity was statistically significantly associated with older age at natural menopause (P(trend) = 0.005). Higher body mass index at age 18 years (P(trend) = 0.0003) and older age at menarche (P(trend) = 0.0003) were also associated with older age at natural menopause. Hispanic ethnicity (vs non-Hispanic whites; HR, 1.17; 95% CI, 1.09-1.26), current smokers (vs never smokers; HR, 1.68; 95% CI, 1.60-1.75 for current light smokers; HR, 1.38; 95% CI, 1.33-1.44 for current heavy smokers), and older age at first full-term pregnancy (HR(≥29, 2+ full-term pregnancies) vs HR(<29, 2+ full-term pregnancies), 1.10; 95% CI, 1.06-1.14) were associated with earlier age at natural menopause. Upon stratification by smoking history, increased physical activity was statistically significantly associated with older age at natural menopause among heavy smokers only (HR(highest quartile) vs HR(lowest quartile), 0.88; 95% CI, 0.81-0.97; P(trend) = 0.02 for former heavy smokers; HR(highest quartile) vs HR(lowest quartile), 0.89; 95% CI, 0.80-0.99; P(trend) = 0.04 for current heavy smokers).

CONCLUSIONS

Age at natural menopause is a complex trait; the determinants of age at natural menopause, including physical activity, may differ by smoking status.

Trace elements and endometriosis: the ENDO study

There has been limited study of trace elements and endometriosis. Using a matched cohort design, 473 women aged 18-44 years were recruited into an operative cohort, along with 131 similarly aged women recruited into a population cohort. Endometriosis was defined as surgically visualized disease in the operative cohort, and magnetic resonance imaging diagnosed disease in the population cohort. Twenty trace elements in urine and three in blood were quantified using inductively coupled plasma mass spectrometry. Logistic regression estimated the adjusted odds (aOR) of endometriosis diagnosis for each element by cohort. No association was observed between any element and endometriosis in the population cohort. In the operative cohort, blood cadmium was associated with a reduced odds of diagnosis (aOR=0.55; 95% CI: 0.31, 0.98), while urinary chromium and copper reflected an increased odds (aOR=1.97; 95% CI: 1.21, 3.19; aOR=2.66; 95% CI: 1.26, 5.64, respectively). The varied associations underscore the need for continued research.

Cigarette smoking and risk of breast cancer in a New Zealand multi-ethnic case-control study

BACKGROUND

The association between breast cancer and tobacco smoke is currently unclear. The aim of this study was to assess the effect of smoking behaviours on the risk of breast cancer among three ethnic groups of New Zealand women.

METHODS

A population-based case-control study was conducted including breast cancer cases registered on the New Zealand Cancer Registry between 2005 and 2007. Controls were matched by ethnicity and 5-year age-group. Logistic regression was used to estimate the association between breast cancer and smoking at different time points across the lifecourse, for each ethnic group. Estimated odds ratios (OR) were adjusted for established risk factors.

RESULTS

The study comprised 1,799 cases (302 Māori, 70 Pacific, 1,427 non-Māori/non-Pacific) and 2,540 controls (746 Māori, 191 Pacific, 1,603 non-Māori/non-Pacific). There was no clear association between smoking and breast cancer for non-Māori/non-Pacific women, although non-Māori/non-Pacific ex-smokers had statistically significant increased risk of breast cancer when smoking duration was 20 years or more, and this remained significant in the fully adjusted model (OR 1.31, 95% CI 1.03 to 1.66). Māori showed more consistent increased risk of breast cancer with increasing duration among current smokers (<20 years OR 1.61, 95% CI 0.55 to 4.74; 20+ years OR 2.03, 95% CI 1.29 to 3.22). There was a clear pattern of shorter duration since smoking cessation being associated with increased likelihood of breast cancer, and this was apparent for all ethnic groups.

CONCLUSION

There was no clear pattern for cigarette smoking and breast cancer incidence in non-Māori/non-Pacific women, but increased risks were observed for Māori and Pacific women. These findings suggest that lowering the prevalence of smoking, especially among Māori and Pacific women, could be important for reducing breast cancer incidence.

Smoking and breast cancer

The potential role of smoking in breast cancer risk has been the subject of over 100 publications, numerous scientific reviews, and animated debate. Tobacco exposure is a well-established cause of lung cancer, and is thought to account for nearly one third of all cancer deaths. Tobacco smoke contains thousands of chemicals, many of which are known to be mammary carcinogens. Although not initially thought to be a tobacco-related cancer, over the last several decades evidence has been accumulating on the role of both active smoking and secondhand smoking in the etiology of breast cancer. The human health evidence has been systematically evaluated not only by several independent researchers but also by several expert agency panels including those of the U.S. Surgeon General, the International Agency for Research on Cancer, the California Environmental Protection Agency, and a coalition of Canadian health agencies. Although the assessments have varied with time and across reviewers, the most recent weight of the evidence has suggested a potentially casual role for active smoking and breast cancer, particularly for long-term heavy smoking and smoking initiation at an early age. The role of secondhand smoking and breast cancer is less clear, although there has been some suggestion for an increased risk for premenopausal breast cancer. Recent studies evaluating the possible modifying role of polymorphisms in genes involved in the metabolism of tobacco products, particularly NAT2, have contributed another dimension to these assessments, although to date that evidence remains equivocal.

Urinary concentrations of estrogens and estrogen metabolites and smoking in caucasian women

BACKGROUND

Smoking has been hypothesized to decrease biosynthesis of parent estrogens (estradiol and estrone) and increase their metabolism by 2-hydroxylation. However, comprehensive studies of smoking and estrogen metabolism by 2-, 4-, or 16-hydroxylation are sparse.

METHODS

Fifteen urinary estrogens and estrogen metabolites (jointly called EM) were measured by liquid chromatography/tandem mass spectrometry (LC/MS-MS) in luteal phase urine samples collected during 1996 to 1999 from 603 premenopausal women in the Nurses' Health Study II (NHSII; 35 current, 140 former, and 428 never smokers). We calculated geometric means and percentage differences of individual EM (pmol/mg creatinine), metabolic pathway groups, and pathway ratios, by smoking status and cigarettes per day (CPD).

RESULTS

Total EM and parent estrogens were nonsignificantly lower in current compared with never smokers, with estradiol significant (P(multivariate) = 0.02). We observed nonsignificantly lower 16-pathway EM (P = 0.08) and higher 4-pathway EM (P = 0.25) and similar 2-pathway EM in current versus never smokers. EM measures among former smokers were similar to never smokers. Increasing CPD was significantly associated with lower 16-pathway EM (P-trend = 0.04) and higher 4-pathway EM (P-trend = 0.05). Increasing CPD was significantly positively associated with the ratios of 2- and 4-pathway to parent estrogens (P-trend = 0.01 and 0.002), 2- and 4-pathway to 16-pathway (P-trend = 0.02 and 0.003), and catechols to methylated catechols (P-trend = 0.02).

CONCLUSIONS

As hypothesized, we observed lower urinary levels of total EM and parent estrogens in active smokers. Our results also suggest smoking is associated with altered estrogen metabolism, specifically increased 2- and 4-hydroxylation, decreased 16-hydroxylation, and decreased catechol methylation.

IMPACT

Our study suggests how smoking might influence estrogen-related cancers and conditions.

Potential contribution of aromatase inhibition to the effects of nicotine and related compounds on the brain

Cigarette smoking continues to be a major public health problem, and while smoking rates in men have shown some decrease over the last few decades, smoking rates among girls and young women are increasing. Practically all of the important aspects of cigarette smoking and many effects of nicotine are sexually dimorphic (reviewed by Pogun and Yararbas, 2009). Women become addicted more easily than men, while finding it harder to quit. Nicotine replacement appears to be less effective in women. This may be linked to the observation that women are more sensitive than men to non-nicotine cues or ingredients in cigarettes. The reasons for these sex differences are mostly unknown. Several lines of evidence suggest that many of the reported sex differences related to cigarette smoking may stem from the inhibitory effects of nicotine and other tobacco alkaloids on estrogen synthesis via the enzyme aromatase (cyp19a gene product). Aromatase is the last enzyme in estrogen biosynthesis, catalyzing the conversion of androgens to estrogens. This review provides a summary of experimental evidence supporting brain aromatase as a potential mediator and/or modulator of nicotine actions in the brain, contributing to sex differences in smoking behavior. Additional research on the interaction between tobacco smoke, nicotine, and aromatase may help devise new, sex specific methods for prevention and treatment of smoking addiction.

Current smoking status may be associated with overt albuminuria in female patients with type 1 diabetes mellitus: a cross-sectional study

BACKGROUND

There are very few clinical reports that have compared the association between cigarette smoking and microangiopathy in Asian patients with type 1 diabetes mellitus (T1DM). The objective of this study was to assess the relationships between urinary protein concentrations and smoking and gender-based risk factors among patients with T1DM.

METHODS

A cross-sectional study of 259 patients with T1DM (men/women = 90/169; mean age, 50.7 years) who visited our hospital for more than 1 year between October 2010 and April 2011 was conducted. Participants completed a questionnaire about their smoking habits. Patient characteristics included gender, age, body mass index, blood pressure, hemoglobin A1c, lipid parameters, and microangiopathy. Diabetic nephropathy (DN) was categorized as normoalbuminuria (NA), microalbuminuria (MA), or overt albuminuria (OA) on the basis of the following urinary albumin/creatinine ratio (ACR) levels: NA, ACR levels less than 30 mg/g creatinine (Cr); MA, ACR levels between 30 and 299 mg/g Cr; and OA, ACR levels over 300 mg/g Cr.

RESULTS

The percentages of current nonsmokers and current smokers with T1DM were 73.0% (n = 189) and 27.0% (n = 70), respectively. In addition, the percentage of males was higher than that of females (52.2% versus 13.6%) in the current smoking population. The percentage of DN was 61.8% (n = 160) in patients with NA, 21.6% (n = 56) in patients with MA, and 16.6% (n = 43) in patients with OA. The percentage of males among OA patients was also higher than that of females (24.4% versus 12.4%). However, current smoking status was associated with OA in females with T1DM only [unadjusted odds ratio (OR), 4.13; 95% confidence interval (CI), 1.45-11.73, P < 0.01; multivariate-adjusted OR, 5.41; 95% CI, 1.69-17.30, P < 0.01].

CONCLUSIONS

Based on our results in this cross-sectional study of Asian patients with T1DM, smoking might be a risk factor for OA among female patients. Further research is needed of these gender-specific results.

Serum cotinine and prognosis in breast cancer

Various studies have suggested that women who smoke have a worse prognosis if they develop breast cancer. Cotinine levels have been measured in sera from 511 patients with stage I and II breast cancer diagnosed between 1975 and 1980, all of whom had complete follow-up. Although the known prognostic factors, axillary nodal status, tumour size and grade were found to be significant, there was no relationship between serum cotinine and metastasis-free survival. A point estimate of serum cotinine was not found to be a determinant of survival in women with early breast cancer.