Polycystic ovary syndrome and risk of breast cancer in premenopausal and postmenopausal women: a nationwide population-based cohort study.

Purpose: Although some reproductive and metabolic characteristics of polycystic ovary syndrome (PCOS) are known risk factors for breast cancer, the evidence regarding a potential association between PCOS and breast cancer is scarce. In this population-based cohort study including all 1,719,452 women born in Denmark between 1940 and 1993, we investigated the association between PCOS and breast cancer.

Methods: PCOS diagnoses, cancer diagnoses, covariates, migrations, and vital status were all obtained from national population and health registers.

Long-Term Health Consequences After Ovarian Removal at Benign Hysterectomy : A Nationwide Cohort Study.

Background: More evidence is needed to substantiate current recommendations about removing ovaries during hysterectomy for benign conditions.

Objective: To compare long-term outcomes in women with and without bilateral salpingo-oophorectomy (BSO) during hysterectomy for benign conditions.

Design: Emulated target trial using data from a population-based cohort.

Hysterectomy and risk of epithelial ovarian cancer by histologic type, endometriosis, and menopausal hormone therapy.

Background: This nationwide, register-based case-control study investigated the association between hysterectomy and risk of epithelial ovarian cancer according to histology and by history of endometriosis and menopausal hormone therapy (MHT) use.

Methods: From the Danish Cancer Registry, all women registered with epithelial ovarian cancer at age 40-79 years during 1998-2016 were identified (n = 6738). Each case was sex- and age-matched to 15 population controls using risk-set sampling.

Ovarian removal and subsequent breast cancer prognosis: a nationwide cohort study.

Purpose: To evaluate whether previous ovarian removal concomitant with benign hysterectomy improves prognosis in a cohort of women with breast cancer.

Methods: In this nationwide register-based cohort study, risk of recurrence and mortality were examined in 4563 women with invasive breast cancer and previous bilateral salpingo-oophorectomy (BSO) concomitant with benign hysterectomy, during 1977-2018. Comparing with benign hysterectomy alone, hazard ratios (HRs) and 95% confidence intervals (CIs) were evaluated by Cox-proportional hazards regression models.

Use of beta-blockers and risk of contralateral breast cancer.

Beta-blockers have shown antineoplastic effects in laboratory studies but epidemiologic evidence in relation to contralateral breast cancer (CBC) is sparse. We investigated postdiagnosis beta-blocker use and risk of CBC in a cohort of 52 723 women with breast cancer by using nationwide Danish health registers and the Danish Breast Cancer Group database. We defined postdiagnosis beta-blocker use as a time-varying covariate starting 1 year after a second prescription was redeemed.

Ovarian removal at or after benign hysterectomy and breast cancer: a nationwide cohort study.

Purpose: Large-scale population-based registry studies investigating the risk of breast cancer after removal of both ovaries at hysterectomy for benign conditions in women with no known genetic predisposition to cancer are needed. We aimed to perform such a study taking into account the age at surgery status and use of hormone replacement therapy (HRT).

Methods: Within the female population of Denmark born 1937-1996, we evaluated breast cancer incidence after unilateral or bilateral oophorectomy concomitant with or after benign hysterectomy in comparison with no surgery and with hysterectomy alone using health registry data during 1978-2016.

Risk of breast cancer among women with benign ovarian tumors: a Danish nationwide cohort study.

Purpose: To assess the association between benign ovarian tumors and subsequent risk of breast cancer, and to examine this association according to type of benign ovarian tumors.

Methods: This nationwide cohort study comprised all Danish women diagnosed with a benign ovarian tumor during 1978-2016 (n = 158,221) identified through the Danish National Patient Register. The cohort was linked to the Danish Cancer Registry to identify all cases of breast cancer, and standardized incidence ratios (SIR) and 95% confidence intervals (CI) were calculated.

Ovarian and tubal cancer in Denmark: an update on incidence and survival.

Introduction: The Nordic countries are areas with a high-incidence of ovarian cancer; however, differences between the countries exist.

Material And Methods: We used the Danish Cancer Registry to identify 11 264 cases of ovarian cancer and 363 cases of tubal cancer during 1993-2013. We calculated age-standardized (world standard population) incidence rates for overall and subtype-specific ovarian cancer, and for tubal cancer.

Risk of cancer among women with polycystic ovary syndrome: a Danish cohort study.

Objective: To assess the association between polycystic ovary syndrome (PCOS) and cancer, especially of the endometrium, breast and ovary.

Methods: The Danish National Patient Register was used to identify 12,070 in- and outpatients in whom PCOS was diagnosed when they were aged 9-49 years during 1977-2012. Using the Danish Cancer Registry, we followed the cohort through 2012 and compared the women's cancer incidence with that of the general Danish female population by means of standardized incidence ratios (SIRs).

Association of maternal self-medication and over-the-counter analgesics for children.

Objective: Self-medication with over-the-counter (OTC) analgesics, such as paracetamol (PCM), among children and adolescents is increasing and constitutes an important public health issue internationally. Reasons for this development are unclear; parental influence is suggested. Our objective was to examine whether self-medication with OTC analgesics among school-aged children is influenced by maternal self-reported health and medicine use, taking the child's frequency of pain into account.