Menopausal symptoms and the risk of young-onset breast cancer

The role of menopausal symptoms on future health and longevity: A systematic scoping review of longitudinal evidence

Women live longer than men but spend more years in poor health. Menopausal symptoms are not generally associated with adverse health outcomes. However, increasingly, evidence suggests they can significantly impact future health and longevity. Understanding the long-term effects of menopausal symptoms will enable clinicians to identify risk factors and intervene with modifications to support healthy aging. This review examined the scope of research investigating the association between menopausal symptoms and future health outcomes. We searched for longitudinal cohort studies. Date and geographical restrictions were not applied. Articles were screened and data extracted using standardised methods. Included studies examined the role of menopausal symptoms on future health developments using a sample who had experienced menopause and were deemed healthy at baseline, with clear reporting of their menopausal status at symptom assessment. We identified 53 eligible studies with data from over 450,000 women enrolled in 28 longitudinal cohorts. Cardiovascular disease, psychiatric disorders, diabetes, and reduced bone mineral density were positively associated with menopausal symptoms. Breast cancer was associated with an asymptomatic menopause. Psychological menopausal symptoms and cognitive decline improved after menopause, except among women from low socioeconomic backgrounds. These findings demonstrate that menopausal symptoms are important indicators for future health risks. Future work should investigate the impact of underexplored menopausal symptoms on future health, such as sleeping problems and urogenital issues, and evaluate whether treating menopausal symptoms could lead to improvements in future health outcomes. Should future research continue to support these findings, clinical guidelines should be updated to support clinical decision-making in menopause care.

Tamoxifen related side effects and their impact on breast cancer incidence: A retrospective analysis of the randomised IBIS-I trial

BACKGROUND

Studies in the adjuvant setting have shown that endocrine therapy related side effects predict breast cancer recurrence risk. Here, we assess the relationship between early reported side effects and incidence of breast cancer in women randomised to tamoxifen for cancer prevention in the International Breast Intervention Study (IBIS)-I trial.

METHODS

Women randomised to tamoxifen in the IBIS-I trial and for whom side effect status was known at the 6-month follow-up visit were included in this analysis. Side effects included in this analysis were hot flushes, vaginal discharge, and vaginal dryness. The primary endpoint was all breast cancer and secondary endpoint was oestrogen receptor (ER) positive breast cancer. Cox proportional hazard models were used to investigate breast cancer incidence in the tamoxifen group with and without side effects reported within 6 months of randomisation.

RESULTS

Women randomised to tamoxifen and reporting hot flushes at the 6-month follow-up visit had a non-statistically significant increase in breast cancer compared to those without hot flushes (HR = 1.26 (0.98-1.62), P = 0.08). A significant higher breast cancer risk was observed for postmenopausal women who reported hot flushes at the 6-month follow-up visit compared to those without hot flushes (HR = 1.59 (1.12-2.26), P = 0.01). A higher risk was observed for ER-positive breast cancer in postmenopausal women (HR = 1.81 (1.19-2.74), P = 0.01). No significant associations between gynaecological side effects and breast cancer occurrence was observed.

CONCLUSIONS

Overall, no association between side effects reported at 6 months and subsequent breast cancer occurrence was observed. Some side effects might be useful markers for breast cancer occurrence in postmenopausal women.

Persistent vasomotor symptoms and breast cancer in the Women's Health Initiative

OBJECTIVE

Vasomotor symptoms (VMS) including hot flashes and night sweats are common during the menopausal transition and may persist. Although VMS pathophysiology is complex, estrogen's efficiency as VMS therapy suggests hormonal environment change may influence this process. As studies of VMS and breast cancer are inconsistent, we examined associations between persistent VMS and breast cancer incidence and mortality.

METHODS

The analytic sample included 25,499 postmenopausal women aged 50 to 79 in the Women's Health Initiative (WHI) without current/former menopausal hormone therapy use with information on VMS status (never vs persistent). Breast cancers were verified by medical record review. Cause of death attribution was enhanced by serial National Death Index queries. Associations between VMS status and breast cancer incidence and mortality was determined using time dependent Cox regression analyses adjusted for breast cancer risk factors.

RESULTS

Through 17.9 years (median) follow-up, 1,399 incident breast cancers were seen. Women with persistent VMS (VMS median duration 10+ years) (n = 9,715), compared to women with never VMS (n = 15,784), had a higher breast cancer incidence (hazard ratio [HR] 1.13 95% confidence interval [CI] 1.02-1.27). While breast cancer-specific mortality was higher in women with persistent VMS (HR 1.33 95% CI 0.88-2.02), the difference was not statistically significant. Persistent VMS status had no influence on breast cancer overall survival (HR 1.02 95% CI 0.81-1.29).

CONCLUSION

Women with persistent VMS are more likely to be diagnosed with breast cancer than women who never experienced VMS, but not more likely to die from breast cancer.

Long-Term Cause-Specific Mortality After Surgery for Women With Breast Cancer: A 20-Year Follow-Up Study From Surveillance, Epidemiology, and End Results Cancer Registries

BACKGROUND

Research into long-term cause-specific mortality of women diagnosed with breast cancer is important because it allows for the splitting of the population into patients who eventually die from breast cancer and from other causes. The adoption of this approach helps to identify patients with an elevated risk of eventual death from breast cancer.

OBJECTIVE

The primary aim of this study was to examine the associations between both sociodemographic and clinicopathologic characteristics and the underlying risks of death from breast cancer and from other causes for women diagnosed with breast cancer. A second aim was to propose a predictive biomarker of cause-specific mortality in terms of treatment and several important characteristics of a patient.

METHODS

A cohort of 16 511 female patients diagnosed with breast cancer in 1990 was obtained from the Surveillance, Epidemiology, and End Results cancer registries and followed for 20 years. A mixture model for the regression analysis of competing risks was used to identify factors and confounders that affected either the eventual cause-specific mortality or conditional cause-specific hazard rates, or both. Missing data were handled with multiple imputation.

RESULTS

Curvilinear relationships of age at diagnosis along with race, marital status, breast cancer type, tumor size, estrogen receptor status, extension, lymph node status, type of surgery, and radiotherapy status were significant risk factors for the cause-specific mortality, with extension and lymph node status appearing to be confounded with the effects of both type of surgery and radiotherapy status. The score obtained from combining a set of predictors showed to be an accurate predictive biomarker.

CONCLUSIONS

In cause-specific mortality of women diagnosed breast cancer, prognosis appears to depend on both sociodemographic and clinicopathologic factors. The predictive biomarker proposed in this study may help identifying the level of seriousness of the disease earlier than traditional methods, potentially guiding future allocation of resources for better patient care and management strategies.

Menopausal vasomotor symptoms and incident breast cancer risk in the Study of Women's Health Across the Nation

PURPOSE

Two case-control studies reported a 50 % decreased breast cancer risk among women who experienced menopausal vasomotor symptoms (VMS), but one cohort study found no association. VMS may be triggered by declining estrogen levels during menopause, whereas elevated estrogen levels have been associated with increased breast cancer risk. VMS may thus be indicative of lower susceptibility to breast cancer.

METHODS

We evaluated this relationship in the longitudinal Study of Women's Health Across the Nation (SWAN), using discrete survival analysis of approximately annual data on VMS and self-reported breast cancer occurrences for up to 13 years of follow-up in 3,098 women who were pre- or early perimenopausal at enrollment.

RESULTS

Over an average 11.4 years of follow-up, 129 incident breast cancer cases were self-reported, and approximately 50 % of participants experienced VMS. Symptomatic women had a reduced risk of breast cancer compared to non-symptomatic women (adjusted HR 0.63, 95 % CI 0.39, 1.00). The association was stronger in the subgroup of women who fully transitioned to postmenopause during follow-up (n = 67 cases, adjusted HR 0.45, 95 % CI 0.26, 0.77).

CONCLUSION

VMS appeared to be a marker of reduced breast cancer risk. Future research is needed to understand the biology underlying this relationship.

Hormone therapy and young-onset breast cancer

Estrogen plus progestin hormone therapy (HT) is associated with an increased risk of postmenopausal breast cancer, but few studies have examined the impact of HT use on the risk of breast cancer in younger women. We assessed the association between estrogen plus progestin HT or unopposed estrogen HT and young-onset breast cancer using data from the Two Sister Study (2008-2010), a sister-matched study of 1,419 cases diagnosed with breast cancer before the age of 50 years and 1,665 controls. We assessed exposures up to a family-specific index age to ensure comparable opportunities for exposures and used propensity scores to control for birth cohort effects on HT use. Ever HT use was uncommon (7% and 11% in cases and controls, respectively). Use of estrogen plus progestin was not associated with an increased risk of young-onset breast cancer (odds ratio = 0.80, 95% confidence interval: 0.41, 1.59). Unopposed estrogen use was inversely associated with the risk of young-onset breast cancer (odds ratio = 0.58, 95% confidence interval: 0.34, 0.99). Duration of use, age at first use, and recency of use did not modify these associations.

Temporal trend, clinicopathologic and sociodemographic characterization of age at diagnosis of breast cancer among US women diagnosed from 1990 to 2009

This paper investigates the distribution of age at diagnosis of female breast cancer and its association with temporal trend, clinicopathologic and sociodemographic variables in the presence of two latent clusters that are directly unobservable. Such clusters help to identify two subpopulations of either young or old patients whose etiologies are thought to be different. A large sample drawn from registry data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results program from 1990 to 2009 was analyzed using a two-component Gaussian mixture model. Evidence of a steady delay of age at diagnosis and an increasing proportion of young patients being diagnosed during the 20-year period was found. Histopathologic effects indicate that duct and lobular carcinomas differ significantly in regard to subpopulation membership, which confirms that they represent different etiologies. While the presence of estrogen receptor status in the model overlaps the effects of other important variables it is highly correlated with, it is found that the grade, extension and size of the tumor along with lymph node involvement status, race and marital status are important predictors of age at diagnosis. The results highlight the significant impacts that such features can have on breast cancer control efforts, and point to the importance of ensuring that medical decision making should use them along with an indicator of the age subpopulation a patient may belong to.

Vasomotor menopausal symptoms are not associated with incidence of breast cancer in a population-based cohort of mid-aged women

BACKGROUND

Recently, two case-control studies showed that vasomotor menopausal symptoms (VMS), i.e. hot flushes (HF) and night sweats (NS), are associated with a decreased risk of breast cancer. Until now, however, no prior studies have prospectively examined the association between VMS and breast cancer incidence. We investigated this in a population-based cohort of mid-aged women in Australia.

METHODS

We included 11,297 women without a history of breast cancer aged 47-52 years from the Australian Longitudinal Study on Women's Health, surveyed every 3 years from 1998 to 2010. Information regarding first invasive breast cancer events and date of diagnosis was obtained from cancer registries. We determined the association between HF and NS and breast cancer occurrence before the subsequent survey, using time-dependent cox regression analysis, adjusting for time-varying lifestyle factors.

RESULTS

At baseline 33.1% of the women reported experiencing HF and 24.6% reported NS. During a mean follow-up of 13.7 years, 348 cases of breast cancer occurred. VMS were not associated with breast cancer; adjusted hazard ratios were 1.09; 95% confidence interval (CI) 0.87-1.35 for HF and 1.06; 95% CI 0.84-1.33 for NS. No significant interactions were found between each of body mass index, alcohol use, current hormone therapy use, menopausal status and VMS and breast cancer (p-values>0.05).

CONCLUSIONS

We did not find an association between VMS and breast cancer incidence. Research in this area is scarce and additional large prospective population-based studies are required to confirm or refute these findings.