Progestin-only and combined oral contraceptives and receptor-defined premenopausal breast cancer risk: The Norwegian Women and Cancer Study

Impact of khat (Catha edulis) and oral contraceptive use on telomerase levels and tumor suppressor genes p53 and p21 in normal subjects and breast cancer patients

This study aimed to evaluate the effects of oral contraceptive (OC) use, khat chewing, and their combined effect on telomerase level and tumor suppressor genes, p53 and p21 in breast cancer (BC) patients and normal volunteers. 140 Yemeni women aged 25-40 years old enrolled, 60 newly diagnosed pretreated BC patients, and 80 control subjects. Venous blood (5 ml) was collected and the results showed BC patients to have significantly raised levels of telomerase, p53, and p21 compared to the control group. The use of OCs significantly raised telomerase in control group with no effect in BC patients; whereas p53 and p21 were significantly increased in BC patients. On the other hand, khat chewing significantly increased p53 in controls and BC patients, whereas p21 was significantly raised in BC patients. The combined use of OCs and khat chewing significantly increased telomerase and p53 in control group, and significantly increased p53 and p21 in BC patients. Telomerase was shown to be a risk factor (OR 4.4) for BC, and the use of OCs was a high-risk factor for increasing telomerase (OR 27.8) in normal subjects. In contrast, khat chewing was shown to be protective (OR 0.142), and the combined use of OCs and khat chewing decreased the risk factor of telomerase from OR 27.8 to 2.1.

Menopausal hormone therapy and breast cancer risk: a population-based cohort study of 1.3 million women in Norway

BACKGROUND

It is important to monitor the association between menopausal hormone therapy (HT) use and breast cancer (BC) risk with contemporary estimates, and specifically focus on HT types and new drugs.

METHODS

We estimated hazard ratios (HR) of BC risk according to HT type, administration route and individual drugs, overall and stratified by body mass index (BMI), molecular subtype and detection mode, with non-HT use as reference.

RESULTS

We included 1,275,783 women, 45+ years, followed from 2004, for a median of 12.7 years. Oral oestrogen combined with daily progestin was associated with the highest risk of BC (HR 2.42, 95% confidence interval (CI) 2.31-2.54), with drug-specific HRs ranging from Cliovelle®: 1.63 (95% CI 1.35-1.96) to Kliogest®: 2.67 (2.37-3.00). Vaginal oestradiol was not associated with BC risk. HT use was more strongly associated with luminal A cancer (HR 1.97, 95% CI 1.86-2.09) than other molecular subtypes, and more strongly with interval (HR 2.00, 95% CI: 1.83-2.30) than screen-detected (HR 1.33, 95% CI 1.26-1.41) BC in women 50-71 years. HRs for HT use decreased with increasing BMI.

CONCLUSIONS

The use of oral and transdermal HT was associated with an increased risk of BC. The associations varied according to HT type, individual drugs, molecular subtype, detection mode and BMI.

Antimicrobial peptide moricin induces ROS mediated caspase-dependent apoptosis in human triple-negative breast cancer via suppression of notch pathway

BACKGROUND

Breast cancer is the world's most prevalent cancer among women. Microorganisms have been the richest source of antibiotics as well as anticancer drugs. Moricin peptides have shown antibacterial properties; however, the anticancer potential and mechanistic insights into moricin peptide-induced cancer cell death have not yet been explored.

METHODS

An investigation through in silico analysis, analytical methods (Reverse Phase-High Performance Liquid Chromatography (RP-HPLC), mass spectroscopy (MS), circular dichroism (CD), and in vitro studies, has been carried out to delineate the mechanism(s) of moricin-induced cancer cell death. An in-silico analysis was performed to predict the anticancer potential of moricin in cancer cells using Anti CP and ACP servers based on a support vector machine (SVM). Molecular docking was performed to predict the binding interaction between moricin and peptide-related cancer signaling pathway(s) through the HawkDOCK web server. Further, in vitro anticancer activity of moricin was performed against MDA-MB-231 cells.

RESULTS

In silico observation revealed that moricin is a potential anticancer peptide, and protein-protein docking showed a strong binding interaction between moricin and signaling proteins. CD showed a predominant helical structure of moricin, and the MS result determined the observed molecular weight of moricin is 4544 Da. An in vitro study showed that moricin exposure to MDA-MB-231 cells caused dose dependent inhibition of cell viability with a high generation of reactive oxygen species (ROS). Molecular study revealed that moricin exposure caused downregulation in the expression of Notch-1, NF-ƙB and Bcl2 proteins while upregulating p53, Bax, caspase 3, and caspase 9, which results in caspase-dependent cell death in MDA-MB-231 cells.

CONCLUSIONS

In conclusion, this study reveals the anticancer potential and underlying mechanism of moricin peptide-induced cell death in triple negative cancer cells, which could be used in the development of an anticancer drug.

Combined and progestagen-only hormonal contraceptives and breast cancer risk: A UK nested case-control study and meta-analysis

BACKGROUND

Current or recent use of combined oral contraceptives (containing oestrogen+progestagen) has been associated with a small increase in breast cancer risk. Progestagen-only contraceptive use is increasing, but information on associated risks is limited. We aimed to assess breast cancer risk associated with current or recent use of different types of hormonal contraceptives in premenopausal women, with particular emphasis on progestagen-only preparations.

METHODS AND FINDINGS

Hormonal contraceptive prescriptions recorded prospectively in a UK primary care database (Clinical Practice Research Datalink [CPRD]) were compared in a nested case-control study for 9,498 women aged <50 years with incident invasive breast cancer diagnosed in 1996 to 2017, and for 18,171 closely matched controls. On average, 7.3 (standard deviation [SD] 4.6) years of clinical records were available for each case and their matched controls prior to the date of diagnosis. Conditional logistic regression yielded odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer by the hormonal contraceptive type last prescribed, controlled for age, GP practice, body mass index, number of recorded births, time since last birth, and alcohol intake. MEDLINE and Embase were searched for observational studies published between 01 January 1995 and 01 November 2022 that reported on the association between current or recent progestagen-only contraceptive use and breast cancer risk in premenopausal women. Fixed effects meta-analyses combined the CPRD results with previously published results from 12 observational studies for progestagen-only preparations. Overall, 44% (4,195/9,498) of women with breast cancer and 39% (7,092/18,171) of matched controls had a hormonal contraceptive prescription an average of 3.1 (SD 3.7) years before breast cancer diagnosis (or equivalent date for controls). About half the prescriptions were for progestagen-only preparations. Breast cancer ORs were similarly and significantly raised if the last hormonal contraceptive prescription was for oral combined, oral progestagen-only, injected progestagen, or progestagen-releasing intrauterine devices (IUDs): ORs = 1.23 (95% CI [1.14 to 1.32]; p < 0.001), 1.26 (95% CI [1.16 to 1.37]; p < 0.001), 1.25 (95% CI [1.07 to 1.45]; p = 0.004), and 1.32 (95% CI [1.17 to 1.49]; p < 0.001), respectively. Our meta-analyses yielded significantly raised relative risks (RRs) for current or recent use of progestagen-only contraceptives: oral = 1.29 (95% CI [1.21 to 1.37]; heterogeneity χ25 = 6.7; p = 0.2), injected = 1.18 (95% CI [1.07 to 1.30]; heterogeneity χ28 = 22.5; p = 0.004), implanted = 1.28 (95% CI [1.08 to 1.51]; heterogeneity χ23 = 7.3; p = 0.06), and IUDs = 1.21 (95% CI [1.14 to 1.28]; heterogeneity χ24 = 7.9; p = 0.1). When the CPRD results were combined with those from previous published findings (which included women from a wider age range), the resulting 15-year absolute excess risk associated with 5 years use of oral combined or progestagen-only contraceptives in high-income countries was estimated at: 8 per 100,000 users from age 16 to 20 years and 265 per 100,000 users from age 35 to 39 years. The main limitation of the study design was that, due to the nature of the CPRD data and most other prescription databases, information on contraceptive use was recorded during a defined period only, with information before entry into the database generally being unavailable. This means that although our findings provide evidence about the short-term associations between hormonal contraceptives and breast cancer risk, they do not provide information regarding longer-term associations, or the impact of total duration of contraceptive use on breast cancer risk.

CONCLUSIONS

This study provides important new evidence that current or recent use of progestagen-only contraceptives is associated with a slight increase in breast cancer risk, which does not appear to vary by mode of delivery, and is similar in magnitude to that associated with combined hormonal contraceptives. Given that the underlying risk of breast cancer increases with advancing age, the absolute excess risk associated with use of either type of oral contraceptive is estimated to be smaller in women who use it at younger rather than at older ages. Such risks need be balanced against the benefits of using contraceptives during the childbearing years.

Hormonal contraception and risk of breast cancer and breast cancer in situ among Swedish women 15–34 years of age: A nationwide register-based study

Background

Evidence on a possible association between newer hormonal contraceptives (HC) and risk of breast cancer remains inconclusive, especially as concerns progestogen-only methods.

Methods

In this nationwide prospective cohort study, all Swedish women aged 15–34 at study start on January 1^st 2005, or who turned 15 years during the study period, were followed until December 31^st 2017. Using information from seven National Registers, we assessed the risk ratio of developing breast cancer and breast cancer in situ in relation to different HC using Poisson regression. We adjusted the analyses for several known confounders of breast cancer.

Findings

This cohort included 1.5 million women providing more than 14 million person-years. During the study period, 3842 women were diagnosed with breast cancer. Compared with never users of any HC, we found no increased risk of developing breast cancer among current users of any combined HC, IRR 1.03 (0.91–1.16), whereas current users of progestogen-only methods had an increased risk of developing breast cancer, IRR 1.32 (1.20–1.45). Across all types of HC, the risk of developing breast cancer appeared to be highest the first five years of use (combined HC IRR 1.39 (1.14–1.69); progestogen-only methods IRR 1.74 (1.44–2.10). The risk disappeared ten years after the women stopped using HC. The absolute risk of breast cancer per 100,000 women-years was 22.4 for never users, 10.9 for current users of combined HC, and 29.8 for current users of progestogen-only methods.

Interpretation

Current use of progestogen-only methods is associated with a small increased risk of developing breast cancer, whereas we could only detect an increased risk among users of combined HC during the first five years of use. This may partly be explained by a selective prescription of progestogen-only methods to women with risk factors for breast cancer, like smoking or obesity. As the absolute risk of breast cancer was small, the many health benefits associated with HC must also be taken into account in contraceptive counselling.

Funding

This study was funded by the Swedish Cancer Society and by the Uppsala County Council, the Faculty of Medicine at Uppsala University.

Exogenous Hormones and Breast Cancer Risk: Contraception, Menopausal Hormone Therapy, and Breast Cancer Survivors

The use of exogenous estrogen and progesterone/progestin medications spans the reproductive and postreproductive lives of millions of women providing control over pregnancy timing, management of premenopausal and postmenopausal symptoms, and prevention of disease, including endometrial and ovarian cancer. These same hormones can also increase the risk of breast cancer in some settings and their use in breast cancer survivors may increase the risk of breast cancer recurrence. Given both the benefits and risks of these exogenous hormones, a detailed understanding of the available scientific evidence is imperative to help counsel individuals in their use across various settings.

Oral contraceptive use by formulation and breast cancer risk by subtype in the Nurses' Health Study II: a prospective cohort study

BACKGROUND

Oral contraceptive use has been associated with a higher breast cancer risk; however, evidence for the associations between different oral contraceptive formulations and breast cancer risk, especially by disease subtype, is limited.

OBJECTIVE

This study aimed to evaluate the associations between oral contraceptive use by formulation and breast cancer risk by disease subtype.

STUDY DESIGN

This prospective cohort study included 113,187 women from the Nurses' Health Study II with recalled information on oral contraceptive usage from 13 years of age to baseline (1989) and updated data on usage until 2009 collected via biennial questionnaires. A total of 5799 breast cancer cases were identified until the end of 2017. Multivariable Cox proportional hazards models estimated hazard ratios and 95% confidence intervals for the associations between oral contraceptive use and breast cancer risk overall and by estrogen and progesterone receptor and human epidermal growth factor receptor 2 status. Oral contraceptive use was evaluated by status of use (current, former, and never), duration of and time since last use independently and cross-classified, and formulation (ie, estrogen and progestin type).

RESULTS

Current oral contraceptive use was associated with a higher risk for invasive breast cancer (hazard ratio, 1.31; 95% confidence interval, 1.09-1.58) when compared with never use, with stronger associations observed for longer durations of current use (>5 years: hazard ratio, 1.56; 95% confidence interval, 1.23-1.99; ≤5 years: hazard ratio, 1.19; 95% confidence interval, 0.95-1.49). Among former users with >5 years since cessation, the risk was similar to that of never users (eg, >5 to 10 years since cessation: hazard ratio, 0.99; 95% confidence interval, 0.88-1.11). Associations did not differ significantly by tumor subtype. In analyses by formulation, current use of formulations containing levonorgestrel in triphasic (hazard ratio, 2.83; 95% confidence interval, 1.98-4.03) and extended cycle regimens (hazard ratio, 3.49; 95% confidence interval, 1.28-9.53) and norgestrel in monophasic regimens (hazard ratio, 1.91; 95% confidence interval, 1.19-3.06), all combined with ethinyl estradiol, was associated with a higher breast cancer risk when compared with never oral contraceptive use. No association was observed for current use of the other progestin types evaluated (norethindrone, norethindrone acetate, ethynodiol diacetate, desogestrel, norgestimate, and drospirenone), however, sample sizes were relatively small for some of the subgroups, limiting these analyses.

CONCLUSION

Current oral contraceptive use was associated with a higher risk for invasive breast cancer regardless of disease subtype, however, the risk in former users was comparable with never users 5 years after cessation. In analyses by progestin type, associations were observed for select formulations containing levonorgestrel and norgestrel. Assessment of the associations for newer progestin types (desogestrel, norgestimate, drospirenone) was limited by sample size, and further research on more recently introduced progestins is warranted.

Combined Oral Contraceptive Use and Breast Cancer Risk: Select Considerations for Clinicians

Combined oral contraceptives (COCs) are commonly used by individuals for contraceptive and noncontraceptive purposes, such as the management of dysmenorrhea or to reduce risk for ovarian and endometrial cancer. However, a common consideration that continues to arise is whether COC use increases breast cancer risk. Many researchers have investigated this, but study results are varied and may be affected by variables such as hormone type, an individual's age, and the duration of COC use. In this article, we summarize select breast cancer risk considerations regarding COC use to assist clinicians when counseling individuals considering using oral contraceptives.

Night shift work, chemical coexposures and risk of female breast cancer in the Norwegian Offshore Petroleum Workers (NOPW) cohort: a prospectively recruited case-cohort study

OBJECTIVES

This study examined the association between night shift work and risk of breast cancer, overall and by hormone receptor subtype, among females in the Norwegian Offshore Petroleum Workers (NOPW) cohort. We also examined the association of coexposure (chlorinated degreasers and benzene) and breast cancer risk, and possible interaction with work schedule.

DESIGN

Prospectively recruited case-cohort study within the NOPW cohort.

SETTING

Female offshore petroleum workers active on the Norwegian continental shelf.

PARTICIPANTS

600 female workers (86 cases and 514 non-cases) were included in the study. We excluded workers that died or emigrated before start of follow-up, had missing work history, were diagnosed with breast cancer or other prior malignancy (except non-melanoma skin cancer) before start of follow-up.

RESULTS

No overall association was found between breast cancer risk and work schedule (HR 0.87, 95% CI 0.52 to 1.46 for work schedule involving night shift vs day shift only). There was no significant association between work schedule and risk of any breast cancer subtype. No significant interactions were found between work schedule and chemical coexposures (breast cancer overall P_{interaction chlorinated degreasers}=0.725 and P_{interaction benzene}=0.175).

CONCLUSIONS

Our results did not provide supporting evidence that work schedule involving night shift affects breast cancer risk in female offshore petroleum workers, but should be considered cautiously due to few cases. Further studies with larger sample sizes are warranted.

Geospatiotemporal and causal inference study of cannabis and other drugs as risk factors for female breast cancer USA 2003-2017

Breast cancer (BC) is the commonest human cancer and its incidence (BC incidence, BCI) is rising worldwide. Whilst both tobacco and alcohol have been linked to BCI genotoxic cannabinoids have not been investigated. Age-adjusted state-based BCI 2003-2017 was taken from the Surveillance Epidemiology and End Results database of the Centers for Disease Control. Drug use from the National Survey of Drug Use and Health, response rate 74.1%. Median age, median household income and ethnicity were from US census. Inverse probability weighted (ipw) multivariable regression conducted in R. In bivariate analysis BCI was shown to be significantly linked with rising cannabis exposure {β-est. = 3.93 [95% confidence interval 2.99, 4.87], P = 1.10 × 10^-15}. At 8 years lag cigarettes:cannabis [β-est. = 2660 (2150.4, 3169.3), P = 4.60 × 10^-22] and cannabis:alcoholism [β-est. = 7010 (5461.6, 8558.4), P = 1.80 × 10^-17] were significant in ipw-panel regression. Terms including cannabidiol [CBD; β-est. = 16.16 (0.39, 31.93), P = 0.446] and cannabigerol [CBG; β-est. = 6.23 (2.06, 10.39), P = 0.0034] were significant in spatiotemporal models lagged 1:2 years, respectively. Cannabis-liberal paradigms had higher BCI [67.50 ± 0.26 v. 65.19 ± 0.21/100 000 (mean ± SEM), P = 1.87 × 10^-11; β-est. = 2.31 (1.65, 2.96), P = 9.09 × 10^-12]. 55/58 expected values >1.25 and 13/58 >100. Abortion was independently and causally significant in space-time models. Data show that exposure to cannabis and the cannabinoids Δ9-tetrahydrocannabinol, CBD, CBG and alcoholism fulfil quantitative causal criteria for BCI across space and time. Findings are robust to adjustment for age and several known sociodemographic, socio-economic and hormonal risk factors and establish cannabinoids as an additional risk factor class for breast carcinogenesis. BCI is higher under cannabis-liberal legal paradigms.

Oral Contraceptive Use and Breast Cancer Risk Assessment: A Systematic Review and Meta-Analysis of Case-Control Studies, 2009-2020

To perform a meta-analysis of case-control studies that addressed the association between oral contraceptive pills (OC) use and breast cancer (BrCa), PubMED (MEDLINE), Embase, and the Cochrane Library were searched to identify case-control studies of OC and BrCa published between 2009 and 2020. We used the DerSimonian-Laird method to compute pooled odds ratios (ORs) and confidence intervals (CIs), and the Mantel-Haenszel test to assess the association between OC use and cancer. Forty-two studies were identified that met the inclusion criteria and we included a total of 110,580 women (30,778 into the BrCa group and 79,802 into the control group, of which 15,722 and 38,334 were using OC, respectively). The conducted meta-analysis showed that the use of OC was associated with a significantly increased risk of BrCa in general, OR = 1.15, 95% CI: 1.01 to 1.31, p = 0.0358. Regarding other risk factors for BrCa, we found that increased risk was associated significantly with early menarche, nulliparous, non-breastfeeding, older age at first parity, postmenopause, obesity, smoking, and family history of BrCa. Despite our conclusion that birth control pills increase the cancer risk being supported by extensive previous studies and meta-analyzes, further confirmation is required.

Crosstalk between progesterone receptor membrane component 1 and estrogen receptor α promotes breast cancer cell proliferation

Progesterone (P4) and estradiol (E2) have been shown to stimulate and regulate breast cancer proliferation via classical nuclear receptor signaling through progesterone receptor (PR) and estrogen receptor α (ERα), respectively. However, the basis of communication between PR/ERα and membrane receptors remains largely unknown. Here, we aim to identify classical and nonclassical endocrine signaling mechanisms that can alter cell proliferation through a possible crosstalk between PR, ERα, and progesterone receptor membrane component 1 (PGRMC1), a membrane receptor frequently observed in breast cancer cells. While P4 and E2 treatment increased cell proliferation of ER+/PR+/PGRMC1 overexpressing breast cancer cells, silencing ERα and PR or treatment with selective estrogen receptor modulator (SERM) tamoxifen, or (PR-antagonist) RU-486 decreased cell proliferation. All four treatments rapidly altered PGRMC1 mRNA levels and protein expression. Furthermore, P4 and E2 treatments rapidly activated EGFR a known interacting partner of PGRMC1 and its downstream signaling. Interestingly, downregulation of ERα by tamoxifen and ERα silencing decreased the expression levels of PGRMC1 with no repercussions to PR expression. Strikingly PGRMC1 silencing decreased ERα expression irrespective of PR. METABRIC and TCGA datasets further demonstrated that PGRMC1 expression was comparable to that of ERα in Luminal A and B breast cancers. Targeting of PR, ERα, and PGRMC1 confirmed that a crosstalk between classical and nonclassical signaling mechanisms exists in ER+ breast cancer cells that could enhance the growth of ER+/PR+/PGRMC1 overexpressing tumors.

Progesterone receptors in normal breast development and breast cancer

Progesterone receptors (PR) play a pivotal role in many female reproductive tissues such as the uterus, the ovary, and the mammary gland (MG). Moreover, PR play a key role in breast cancer growth and progression. This has led to the development and study of different progestins and antiprogestins, many of which are currently being tested in clinical trials for cancer treatment. Recent reviews have addressed the role of PR in MG development, carcinogenesis, and breast cancer growth. Thus, in this review, in addition to making an overview on PR action in normal and tumor breast, the focus has been put on highlighting the still unresolved topics on hormone treatment involving PR isoforms and breast cancer prognosis.

National and Subnational Incidence, Mortality, and Years of Life Lost Due to Breast Cancer in Iran: Trends and Age-Period-Cohort Analysis Since 1990

Breast cancer is the most common cancer among women, causing considerable burden and mortality. Demographic and lifestyle transitions in low and low-middle income countries have given rise to its increased incidence. The successful management of cancer relies on evidence-based policies taking into account national epidemiologic settings. We aimed to report the national and subnational trends of breast cancer incidence, mortality, years of life lost (YLL) and mortality to incidence ratio (MIR) since 1990. As part of the National and Subnational Burden of Diseases project, we estimated incidence, mortality and YLL of breast cancer by sex, age, province, and year using a two-stage spatio-temporal model, based on the primary dataset of national cancer and death registry. MIR was calculated as a quality of care indicator. Age-period-cohort analysis was used to distinguish the effects of these three collinear factors. A significant threefold increase in age-specific incidence at national and subnational levels along with a twofold extension of provincial disparity was observed. Although mortality has slightly decreased since 2000, a positive mortality annual percent change was detected in patients aged 25-34 years, leading to raised YLLs. A significant declining pattern of MIR and lower provincial MIR disparity was observed. We observed a secular increase of breast cancer incidence. Further evaluation of risk factors and developing national screening policies is recommended. A descending pattern of mortality, YLL and MIR at national and subnational levels reflects improved quality of care, even though mortality among younger age groups should be specifically addressed.

National and Subnational Incidence, Mortality, and Years of Life Lost Due to Breast Cancer in Iran: Trends and Age-Period-Cohort Analysis Since 1990

Breast cancer is the most common cancer among women, causing considerable burden and mortality. Demographic and lifestyle transitions in low and low-middle income countries have given rise to its increased incidence. The successful management of cancer relies on evidence-based policies taking into account national epidemiologic settings. We aimed to report the national and subnational trends of breast cancer incidence, mortality, years of life lost (YLL) and mortality to incidence ratio (MIR) since 1990. As part of the National and Subnational Burden of Diseases project, we estimated incidence, mortality and YLL of breast cancer by sex, age, province, and year using a two-stage spatio-temporal model, based on the primary dataset of national cancer and death registry. MIR was calculated as a quality of care indicator. Age-period-cohort analysis was used to distinguish the effects of these three collinear factors. A significant threefold increase in age-specific incidence at national and subnational levels along with a twofold extension of provincial disparity was observed. Although mortality has slightly decreased since 2000, a positive mortality annual percent change was detected in patients aged 25-34 years, leading to raised YLLs. A significant declining pattern of MIR and lower provincial MIR disparity was observed. We observed a secular increase of breast cancer incidence. Further evaluation of risk factors and developing national screening policies is recommended. A descending pattern of mortality, YLL and MIR at national and subnational levels reflects improved quality of care, even though mortality among younger age groups should be specifically addressed.

W. WA, Yunda DK, Pranata R. The Association Between Triglyceride-Glucose Index as a Marker of Insulin Resistance and the Risk of Breast Cancer

BACKGROUND

This study aims to evaluate the association and dose-response between triglyceride-glucose (TyG) index and breast cancer.

METHOD

This is a multicenter case-control study conducted in six public referral hospitals in Indonesia. Cases are individuals aged 19 years or above who were diagnosed with breast cancer within 1 year of diagnosis, based on histopathology and immunohistochemistry. Controls were recruited from corresponding hospitals. TyG index was determined by the formula: ln (fasting TG [mg/dl] × fasting glucose [mg/dl]).

RESULTS

There were 212 participants in the breast cancer group and 212 participants in the control group. TyG index was higher in patients with breast cancer (median 8.65 [7.38, 10.9] vs. 8.30 [7.09, 10.84], p < 0.001). When compared with TyG quartile of Q1, Q4 was associated with an OR of 2.42 (1.77, 3.31), p < 0.001, Q3 was associated with an OR of 1.53 (1.21, 1.93), p < 0.001, Q2 was associated with an OR of 1.39 (1.12, 1.73), p = 0.002 for the risk of breast cancer. The dose-response relationship was nonlinear (p < 0.001). On univariate analysis, smoking (OR 2.15 [1.44, 3.22], p < 0.001), use of contraception (1.73 [1.15, 2.60], p = 0.008), alcohol consumption (OR 2.04 [0.96, 4.35], p = 0.064), and TyG Index >8.87 (OR 3.08 [1.93, 4.93], p < 0.001) were associated with risk of breast cancer. Independently associated with increased risk of breast cancer included smoking (OR 1.93 [1.23, 3.01], p = 0.004), use of contraception (OR 1.59 [1.02, 2.48], p = 0.039), and TyG Index >8.87 (OR 2.93 [1.72, 4.98], p < 0.001).

CONCLUSION

TyG index was associated with breast cancer in a nonlinear dose-response fashion.

Premenopausal Use of Progestogens and Cutaneous Melanoma Risk: A French Prospective Cohort Study

We investigated the influence of premenopausal use of progestogens on melanoma using data from E3N (Etude Epidémiologique Auprès de Femmes de l'Education Nationale), a prospective cohort of 98,995 French women, aged 40-65 years at inclusion. We used Cox models to adjust for age and melanoma risk factors. Over 1992-2008, 540 melanoma cases were ascertained among 79,558 women. We found a modest association between self-reported progestogen use and melanoma risk (hazard ratio (HR) = 1.23, 95% confidence interval (CI) = 1.02, 1.47), which was reduced after adjustment for melanoma risk factors (HR = 1.15, 95% CI: 0.95, 1.39). There was no heterogeneity across types of progestogens (P = 0.22), and use of multiple progestogens was positively associated with melanoma risk (HR = 1.33, 95% CI: 1.04, 1.70). Among users, we found no relationship with duration of progestogen use, age at start and last use, and time since first and last use. Although our results did not show evidence of a confounding effect of sun exposure, progestogen users had lower levels of residential sun exposure and were more likely to report sunscreen use, suggesting specific sun exposure profiles in users. Our findings do not support a strong influence of progestogens on melanoma risk. Further research is needed to confirm these results.

Breast cancer

Breast cancer is the most frequent malignancy in women worldwide and is curable in ~70-80% of patients with early-stage, non-metastatic disease. Advanced breast cancer with distant organ metastases is considered incurable with currently available therapies. On the molecular level, breast cancer is a heterogeneous disease; molecular features include activation of human epidermal growth factor receptor 2 (HER2, encoded by ERBB2), activation of hormone receptors (oestrogen receptor and progesterone receptor) and/or BRCA mutations. Treatment strategies differ according to molecular subtype. Management of breast cancer is multidisciplinary; it includes locoregional (surgery and radiation therapy) and systemic therapy approaches. Systemic therapies include endocrine therapy for hormone receptor-positive disease, chemotherapy, anti-HER2 therapy for HER2-positive disease, bone stabilizing agents, poly(ADP-ribose) polymerase inhibitors for BRCA mutation carriers and, quite recently, immunotherapy. Future therapeutic concepts in breast cancer aim at individualization of therapy as well as at treatment de-escalation and escalation based on tumour biology and early therapy response. Next to further treatment innovations, equal worldwide access to therapeutic advances remains the global challenge in breast cancer care for the future.

Health outcomes associated with use of hormonal contraception: breast cancer

PURPOSE OF REVIEW

To review recent literature on health outcomes associated with use of hormonal contraception with a focus on breast cancer.

RECENT FINDINGS

A large cohort study documented an increased risk of breast cancer among hormonal contraceptive users compared to those who had never used hormonal contraception. The overall relative risk of breast cancer among current or recent users was 1.2 [95% confidence interval (CI), 1.14-1.26]. Overall, this translates into one additional case of breast cancer for every 7690 users of hormonal contraception. Recent publications have also documented a decrease in risk for endometrial, ovarian, and colorectal cancers among hormonal contraceptive users. Based on these data, it is estimated that a third of endometrial and ovarian cancers and a fifth of colorectal cancers were prevented with combined oral contraceptive use.

SUMMARY

Several factors must be taken into consideration regarding the risk of breast cancer associated with hormonal contraceptive use. Contraceptive benefits related to preventing unintended pregnancy are protective against associated maternal morbidity and mortality. Noncontraceptive benefits of protecting against other types of cancers must also be considered. Overall, breast cancer risk is low among hormonal contraceptive users and women should be counseled accordingly.

Recent Use of Oral Contraceptives and Risk of Luminal B, Triple-Negative, and HER2-Overexpressing Breast Cancer

Oral contraceptive use is a well-established risk factor for breast cancer and is common among reproductive-aged women in the USA. Its relationship with less common, more aggressive, molecular subtypes is less clear. A population-based case-case analysis was conducted comparing three less common molecular subtypes to luminal A breast cancer among 1701 premenopausal cases aged 21-49 diagnosed with a first primary invasive breast cancer between 2004 and 2015. Medical record reviews and structured interviewer-administered questionnaires were used to collect data on oral contraceptive use. Multinomial logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (95% CI) for recency of oral contraceptive use for each subtype of breast cancer. Current use of oral contraceptives and use within 5 years before diagnosis was associated with lower odds of H2E tumors compared with luminal A tumors [OR = 0.5, 95% CI: 0.3, 0.9 and OR = 0.5, 95% CI: 0.4, 0.8, respectively] with increasing duration associated with decreasing odds (p for trend < 0.05). Oral contraceptive use was not associated with risks of TN or luminal B breast cancer. Oral contraceptive use may be more strongly positively associated with risks of luminal A, luminal B, and TN breast cancer than with risk of H2E tumors. These findings contribute to the etiological understanding of different molecular subtypes of breast cancer.

A cohort study of 49 933 women with surgically verified endometriosis: Increased incidence of breast cancer below the age of 40

INTRODUCTION

The association between endometriosis and breast cancer is unclear. We assessed the risk of breast cancer in women with surgically verified endometriosis, with special focus on the age at cancer diagnosis, time from endometriosis diagnosis and breast cancer histology.

MATERIAL AND METHODS

All women with first endometriosis-associated diagnoses occurring concomitantly with relevant surgical codes during 1987-2012 were retrieved from the Finnish Hospital Discharge Register in Finland. Breast cancers diagnosed after the endometriosis diagnosis were identified from the Finnish Cancer Registry. The Finnish female population served as the reference. The endometriosis cohort consisted of 49 933 women (23 210 cases of ovarian, 20 187 peritoneal and 2372 deep infiltrating endometriosis). The outcome measure was the standardized incidence ratio (SIR) with 95% confidence interval (95% CI) of breast cancer calculated for the whole cohort and for the subtypes of endometriosis, stratified by the age at breast cancer diagnosis, histology and time from endometriosis diagnosis.

RESULTS

The overall risk of breast cancer (1555 cases) was similar to the reference population (SIR 0.99; 95% CI 0.94-1.03), did not differ in types of endometriosis, and was similar for ductal and lobular breast cancer. However, the SIR of breast cancer was increased in the age group of 20-29 years (SIR 4.44; 95% CI 2.22-7.94) and in the age group of 30-39 years (SIR 1.28; 95% CI 1.03-1.57). The risk of in situ breast cancer (170 cases) was increased in the entire endometriosis cohort (SIR 1.25; 95% CI 1.07-1.44).

CONCLUSIONS

The overall risk of breast cancer in women with surgically verified endometriosis was similar to that of general population. However, the risk of breast cancer at young age was increased. Young women with surgically verified endometriosis represent highly symptomatic patients with more frequent surgeries and additional therapies that might also contribute to the risk of breast cancer.

Oral Contraceptive and Breast Cancer Risks: a Case Control Study in Six Referral Hospitals in Indonesia

Objective: This study aimed to understand the effects of the use of oral contraceptive to breast cancer risk in six referral hospitals in Indonesia. Methods: The research design was hospital based case-control, conducted in 2013. Population was women patients aged 15 years and above in six cancer-referral hospitals in five provinces. Total of 762 people were included in this study consisting of 381 who are diagnosed with breast cancer as confirmed by histopathologic examination in inpatient surgery ward, and 381 people who are not diagnosed with breast cancer based on interview in outpatient surgery ward as control group. A set of data were collected including the use of oral contraceptives, age, early menarche, childbirth status, breastfeeding status, obesity, unhealthy diet, history of benign breast tumors, family history of breast cancer, and age of menopause. Result: Results showed that Odds Ratio (OR) of patients using oral contraceptive <6 years was 1.93 (95% CI 1.23 – 3.03) and OR of those using oral contraceptive ≥ 6 years was 2.90 (95% CI 1.65– 5.09) as compared to people who did not use oral contraceptive. Conclusion: Use of oral contraceptive in patients was indicated to increase the risk of breast cancer. Longer the duration of using oral contraceptive tend to have higher the risk of breast cancer.

Rethinking the carcinogenesis of breast cancer: The theory of breast cancer as a child deficiency disease or a pseudo semi-allograft

The theory of breast cancer as a child deficiency disease is an inversion of the current paradigm, which considers full-term pregnancies to be a protective factor and uses nulliparous women as the reference group. Instead, the theory of breast cancer as a child deficiency disease says that women with the highest parity (about 20, which is the limit of human fertility) are those with the lowest risk and should be used as the reference group in risk estimations. This theory is explained biologically by converting parity from the simple value of number of children into an understanding of the long-lasting biological and immunological effects of pregnancy. These effects can be reflected, as measured by functional genomics, in gene expression of the immune cells in the blood. Each pregnancy represents a unique fetus or semi-allograft, which provokes the creation and deposit of memory cell clones in the mother. Gene expression levels have been found to change linearly with number of full-term pregnancies in healthy women, but not in breast cancer patients. High hormone levels are necessary for a successful pregnancy, as they modulate the immune response from adaptive to innate in order to protect the fetus (considered as a semi-allograft) from rejection. At the end of the pregnancy, hormone levels drop, and the immune system recognizes the semi-allograft, but not in time for rejection to occur before birth. High hormones levels are also classified as carcinogens illustrating that carcinogenesis in the breast could be viewed as a war or balance between later exposures to hormonal carcinogens and the protection of the immune system. We propose that breast tumors are pseudo semi-allografts made up of transformed breast tissue cells. Assuming that the sensitivity to the exposure to increased levels of endogenous or exogenous hormones in women with breast cancer mimic those that occur in pregnancy, these breast tumor cells are protected against the body's immune reaction, just as the fetus is during pregnancy. However, with more pregnancies, the potential to eradicate the pseudo semi-allograft might increase due to enhanced immune surveillance. The theory of breast cancer as a child deficiency disease proposes that the protective effect of pregnancy on breast cancer incidence via the immune system is independent of other risk factors.

Hormonal contraceptives and breast cancer: Clinical data

The endocrine background of breast cancer has raised questions about the increase in risk that might bear the use of hormonal contraceptives. This has been a particular issue in the case of young women, who constitute the population of contraceptive consumers. Observational studies have been the main source of evidence, which has mainly limited to the combined estrogen-progestogen preparations, the popular pill. Studies in the 80's and 90's of the past century found a small, around a 20%, increase in risk. The translation in absolute number of excess cases has been exiguous because the prevalence of the disease is relatively small in premenopausal women. Moreover, the risk slowly seemed to disappear after 5-10 years of use. The more sophisticated analyses provided by new technologies, together with the powerful central registries in some countries, has confirmed increased risk of similar size. Recent preparations, with lower doses of estrogens and new progestogenic molecules, have not substantially modified the risk size. The impact of progestogen only alternatives, either pills or progestogen-loaded intrauterine devices, seems to be similar, but the evidence is still insufficient. Whether there is a preferential effect on histological or molecular subtypes of breast tumours is being debated yet. The data on women at higher risk, either with mutations of the BRCA1/2 genes or with familial weight, have not found specific response patterns, but the experience is still meagre. It is of interest that long-term follow up data on women who enrolled in the initial cohorts, like that of the Royal College of General Practitioners', have shown a considerable protection against cancer of the ovary (relative risk, RR 0.67), endometrium (RR 0.66), or colorectum (RR 0.81).