Migraine in postmenopausal women and the risk of invasive breast cancer

Considerations for hormonal therapy in migraine patients: a critical review of current practice

INTRODUCTION

Migraine, a neurovascular headache disorder, is a leading cause of disability worldwide. Within the multifaceted pathophysiology of migraine, hormonal fluctuations play an evident triggering and exacerbating role, pointing toward the need for identification and proper usage of both existing and new hormonal targets in migraine treatment.

AREAS COVERED

With a threefold higher incidence of migraine in women than in men, the authors delve into sex hormone-related events in migraine patients. A comprehensive overview is given of existing hormonal therapies, including oral contraceptives, intrauterine devices, transdermal and subcutaneous estradiol patches, gnRH-agonists, oral testosterone, and 5α reductase inhibitors. The authors discuss their effectiveness and risks, noting their suitability for different patient profiles. Next, novel evolving hormonal treatments, such as oxytocin and prolactin, are explored. Lastly, the authors cover hormonal conditions associated with migraine, such as polycystic ovary syndrome, endometriosis, and transgender persons receiving gender affirming hormone therapy, aiming to provide more personalized and effective solutions for migraine management.

EXPERT OPINION

Rigorous research into both existing and new hormonal targets, as well as the underlying pathophysiology, is needed to support a tailored approach in migraine treatment, in an ongoing effort to alleviate the impact of migraine on individuals and society.

Effect of genetic liability to migraine and its subtypes on breast cancer: a mendelian randomization study

BACKGROUND

The relationship between migraine and breast cancer risk has generated conflicting findings. We attempted to assess the association between migraine and breast cancer risk using Mendelian randomization (MR) analysis.

METHODS

We selected genetic instruments associated with migraine from a recently published genome-wide association studies (GWAS). Inverse variant weighted (IVW) analysis was adopted as the main method, and we also performed the weighted-median method and the MR‒Egger, MR pleiotropy residual sum and outlier (MR-PRESSO), and MR Robust Adjusted Profile Score (MR-RAPS) methods as supplements.

RESULTS

Our MR suggested that any migraine (AM) was a risk factor for overall breast cancer (IVW: odds ratio (OR) = 1.072, 95% confidence intervals (CI) = 1.035-1.110, P = 8.78 × 10- 5, false discovery rate (FDR) = 7.36 × 10- 4) and estrogen receptor-positive (ER+) breast cancer (IVW: OR = 1.066, 95% CI = 1.023-1.111, P = 0.0024; FDR = 0.0108) but not estrogen receptor-negative (ER-) breast cancer. In its subtype analysis, women with a history of migraine without aura (MO) had an increased risk of ER- breast cancer (IVW: OR = 1.089, 95% CI = 1.019-1.163, P = 0.0118, FDR = 0.0354), and MO was suggestively associated with the risk of overall breast cancer (FDR > 0.05 and IVW P < 0.05). No significant heterogeneity or horizontal pleiotropy was found in the sensitivity analysis.

CONCLUSION

This study suggested that women with AM have an increased risk of overall breast cancer and ER + breast cancer. MO was suggestively associated with the risk of overall breast cancer and ER- breast cancer.

Imaging Correlates between Headache and Breast Cancer: An [18F]FDG PET Study

This study aimed to examine brain metabolic patterns on [18F]Fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) in breast cancer (BC), comparing patients with tension-type headache (TTH), migraine (MiG), and those without headache. Further association with BC response to neoadjuvant chemotherapy (NAC) was explored. In this prospective study, BC patients eligible for NAC performed total-body [18F]FDG PET/CT with a dedicated brain scan. A voxel-wise analysis (two-sample t-test) and a multiple regression model were used to compare brain metabolic patterns among TTH, MiG, and no-headache patients and to correlate them with clinical covariates. A single-subject analysis compared each patient's brain uptake before and after NAC with a healthy control group. Primary headache was diagnosed in 39/46 of BC patients (39% TTH and 46% MiG). TTH patients exhibited hypometabolism in specific brain regions before NAC. TTH patients with a pathological complete response (pCR) to NAC showed hypermetabolic brain regions in the anterior medial frontal cortex. The correlation between tumor uptake and brain metabolism varied before and after NAC, suggesting an inverse relationship. Additionally, the single-subject analysis revealed that hypometabolic brain regions were not present after NAC. Primary headache, especially MiG, was associated with a better response to NAC. These findings suggest complex interactions between BC, headache, and hormonal status, warranting further investigation in larger prospective cohorts.

The Role of Female Reproductive Hormones in the Association between Migraine and Breast Cancer: An Unanswered Question

Accumulating epidemiological studies have investigated a possible interconnection between migraine (Mi) and breast cancer (BC) because of the strong link between these diseases and female reproductive hormones. This review aims to consolidate findings from epidemiological studies and explore biologically plausible hypothetical mechanisms related to hormonal pathways. Current evidence suggests a protective role of Mi in BC development, particularly in case-control studies but not in cohort ones. The inconsistency among studies may be due to several reasons, including diagnostic criteria for Mi and the age gap between the development of these two diseases. Furthermore, recent research has challenged the concept of a net beneficial effect of Mi on BC, suggesting a more complex relationship between the two conditions. Many polymorphisms/mutations in hormone-related pathways are involved in at least one of the two conditions. The most promising evidence has emerged for a specific alteration in the estrogen receptor 1 gene (rs2228480). However, the possible specific mutation or polymorphism involved in this association has not yet been identified. Further studies with robust methodologies are needed to validate the protective role of Mi in BC and fully elucidate the precise nature of this causal relationship.

Migraine and Risk of Breast Cancer: A Systematic Review and Meta-analysis

Migraine and breast cancer are 2 prevalent diseases with high morbidity and mortality rates world-wide. There have been inconsistent reports regarding the association between migraine and risk of breast cancer. This systematic review and meta-analysis aimed to assess the risk of breast cancer in patients with migraine. By December, 1, 2022, we searched PubMed, Web of Science, Scopus, and Cochrane Library databases. Odds ratio (OR), hazard ratio (HR), and 95% confidence intervals (CIs) were extracted or assessed to determine the pooled risk estimate using a random-effects model. We use the Newcastle-Ottawa Scale (NOS) to evaluate the quality of studies. We included 9 studies involving 393,282 participants. The pooled analysis showed that patients with migraine had a slightly low risk of breast cancer (OR 0.82, 95% CI, 0.72-0.94; P = .003), especially in case-control studies (OR 0.69, CI: 0.60-0.81, I² = 74.1%, p < .001), and hormone receptor-positive breast cancer (OR 0.76, CI: 0.63-0.91; I² = 88.6%; p = .003). Our findings demonstrate a slightly low risk of breast cancer, especially hormone receptor-positive breast cancer, in patients with migraine.

Profiling the Spectrum of Headache Disorders on 440 Breast Cancer Patients: Highlights on Clinical and Pathological Mechanisms

Although widely studied, the association between migraines (M) and breast cancer (BC) risk remains evasive. In this prospective single-center study, 440 early or locally advanced BC patients were enrolled at IRCCS Humanitas Research Hospital. Clinical and demographical data were collected. Those who suffered from headaches were evaluated with the International Classification of Headache Disorders. M was found to be significantly more prevalent in BC patients: 56.1% versus an expected prevalence of 17% in the global population. M patients showed a higher risk of having stage II or III BC than stage I, which was more frequently found in the non-headache population. Interestingly, the frequency of headache attacks was positively correlated with estrogen (r = 0.11, p = 0.05) and progesterone (r = 0.15, p = 0.007) expression, especially in patients with migraine without aura. The higher the expression of hormone receptors in BC, the higher the headache frequency. Moreover, patients suffering from headaches showed an overall earlier onset of BC. Our findings challenge the idea of a net preventive role of M on BC, suggesting a rather complex interaction in which M mostly influences some BC subtypes and vice versa. Further multi-center studies with extended follow-up are needed.

The association between migraine and breast cancer risk: A systematic review and meta-analysis

Background

Migraines is likely to play a protective role in the risk of breast cancer. Some studies have shown that there is an inverse relationship between migraine and breast cancer, and some studies have not found an association; therefore, results from previous studies have been inconclusive and we conducted a meta-analysis to evaluate association between migraine and breast cancer.

Methods

PubMed, EMBASE, Scopus and Web of Science were searched to identify studies on the association between migraine and breast cancer from January 1, 2000 through March 12, 2021. The pooled relative risk (RR) and the 95% confidence intervals (CI) was used to measure this relationship by assuming a random effects meta-analytic model.

Results

A total of 10 studies were included. Our study revealed that there was statistically significant inverse relationship between migraine and breast cancer in case-control studies 0.68 [95% CI: 0.56, 0.82], but no significant relationship was found in cohort studies 0.98 [95% CI: 0.91, 1.06]. Also, migraine reduced the risk of ductal carcinoma 0.84 [95% CI: 0.73, 0.96], and lobular carcinoma 0.83 [95% CI: 0.73, 0.96]. With respect to ER_PR status no association between migraine and breast cancer was found. We found no evidence of publication bias.

Conclusion

Our analysis demonstrated a statistically significantly inverse relationship between migraine and total risk of breast cancer only in case-control studies. In summary, cohort studies do not support an inverse association between migraine and incident breast cancer. While in case-control studies, migraine has an inverse association with ductal carcinoma and lobular carcinoma of breast.

A pilot analysis of headache disorders in breast cancer patients

INTRODUCTION

The interaction between breast cancer and migraine is complex and not fully elucidated. Large epidemiological studies point towards a beneficial effect of migraines on breast cancer (BC). We aimed to investigate the BC-migraine relationship, with strict data checks and clinical evaluations of both BC and common headache forms.

METHODS

Consecutive BC patients were evaluated with the International Classification of Headache Disorders. Clinical data on the BC subtypes and treatments were collected. Parametric and nonparametric statistics were used according to data distributions.

RESULTS

Fifty patients were recruited. The mean age was 53.5 ± 12.5 years; 42% were postmenopausal, 52% were premenopausal, and 6% were peri-menopausal. Eleven patients were diagnosed as luminal A, nine as luminal B, 24 as HER2-positive (HER2 +), six as triple-negative BC. Thirty-eight (76%) patients had hormone receptor-positive disease. Ninety-two percent received chemotherapy, 66% received endocrine therapy, and 52% received radiotherapy. Nine out of 50 reported a worsening of headache after systemic treatment. Migraine was diagnosed in 29 patients (18 with menstrual migraine), tension-type headache (TTH) in nine, and no headache in 12. Patients with migraine were younger (48.4 ± 10.7 vs. 60.5 ± 12; p < 0.01). Patients with migraine and TTH had a higher chance of having a HER2 + BC (p < 0.05). Active migraine was associated with a higher expression of estrogen receptors (p = 0.04).

CONCLUSIONS

Patients with active migraine had higher estrogen receptor expression, while migraine and TTH patients mainly had HER2 + BC. This association was not known earlier and could be helpful to understand deeper the relationship between BC and headache.

Migraine, headache, and mortality in women: a cohort study

BACKGROUND

Migraine carries a high global burden, disproportionately affects women, and has been implicated as a risk factor for cardiovascular disease. Migraine with aura has been consistently associated with increased risk of cardiovascular mortality. However, published evidence on relationships between migraine or non-migraine headache and all-cause mortality is inconclusive. Therefore, we aimed to estimate the effect of non-migraine headache and migraine as well as migraine subtypes on all-cause and cause-specific mortality in women.

METHODS

In total, 27,844 Women's Health Study participants, aged 45 years or older at baseline, were followed up for a median of 22.7 years. We included participants who provided information on migraine (past history, migraine without aura, or migraine with aura) or headache status and a blood sample at study start. An endpoints committee of physicians evaluated reports of incident deaths and used medical records to confirm deaths due to cardiovascular, cancer, or female-specific cancer causes. We used multivariable Cox proportional hazards models to estimate the effect of migraine or headache status on both all-cause and cause-specific mortality.

RESULTS

Compared to individuals without any headache, no differences in all-cause mortality for individuals suffering from non-migraine headache or any migraine were observed after adjustment for confounding (HR = 1.01, 95%CI, 0.93-1.10 and HR = 0.96, 95% CI: 0.89-1.04). No differences were observed for the migraine subtypes and all-cause death. Women having the migraine with aura subtype had  a higher mortality due to cardiovascular disease (adjusted HR = 1.64, 95%CI: 1.06-2.54). As an explanation for the lack of overall association with all-cause mortality, we observed slightly protective signals for any cancer and female-specific cancers in this group.

CONCLUSIONS

In this large prospective study of women, we found no association between non-migraine headache or migraine and all-cause mortality. Women suffering from migraine with aura had an increased risk of cardiovascular death. Future studies should investigate the reasons for the increased risk of cardiovascular mortality and evaluate whether changes in migraine patterns across the life course have differential effects on mortality.

Association Between Migraine and Breast Cancer Risk: A Population-Based Cohort Study and Literature Review

Objective: Previous case-control studies have suggested that women with migraine have lower risk of developing breast cancer, but conflicting results were noted in cohort studies. We investigated the association between migraine and breast cancer incidence in a nationwide population-based cohort study. Methods: We identified 25,606 women with migraine between 2000 and 2013 from the National Health Insurance Research Database in Taiwan. Each migraineur was randomly frequency matched with four women without migraine by age and index year of migraine diagnosis. Cox's proportional hazard regression analysis was performed to estimate the association between migraine on the risk of developing breast cancer. Results: With a mean follow-up of 7.3 years, 234 and 978 breast malignancies occurred in the migraine cohort and matched cohort, respectively. Migraine was not associated with the risk of breast cancer (adjusted hazard ratio = 1.03, 95% confidence interval = 0.89-1.21). Among women with migraine, independent risk factors for breast cancer included older age, alcohol-related illness, and receipt of a greater number of breast cancer screening examinations, and independent protective factors included the use of antihypertensive agents, statins, and nonsteroidal anti-inflammatory drugs. Further analyses indicated that women with ≥4 medical visits for migraine per year had a significantly greater risk of breast cancer than the matched cohort. Conclusions: Migraine was not associated with a decreased risk of developing breast cancer among Taiwanese women. Further prospective studies on other geographic populations or on the association between migraine frequency and the risk of developing breast cancer are warranted to validate our findings.

Migraine and invasive epithelial ovarian cancer risk in the Nurses' Health Study II and the Women's Health Study

Migraine is a common primary headache disorder, which predominantly impacts women. Recently, migraine has been hypothesized to be associated with hormonally related cancers; however, the potential association between migraine and ovarian cancer has not been studied. Therefore, we evaluated the association between migraine and invasive epithelial ovarian cancer risk in two prospective cohorts, the Nurses' Health Study II (NHSII) and the Women's Health Study (WHS). Our prospective analysis included 113,124 NHSII participants aged 25-42 at study baseline as well as 33,490 participants in the WHS who were 45 years or older at study entry. We used Cox proportional hazards models to estimate the hazard ratios (HR) and 95% confidence intervals (CIs) for the association between migraine and ovarian cancer risk in each cohort. In secondary analyses, we stratified by age and menopausal status. After adjusting for potential covariates, there was no statistically significant association between migraine and ovarian cancer risk in either the NHSII (HR = 1.29, 95%CI: 0.96, 1.74) or the WHS (HR = 0.60, 95%CI: 0.34, 1.06). In stratified analysis in the NHSII, there was a statistically significant positive association between migraine and ovarian cancer risk among women <45 years of age (HR = 1.76, 95%CI: 1.01, 3.07). We did not observe a clear association between migraine and ovarian cancer risk in two large prospective cohort studies.

Postmenopausal breast cancer: European challenge and innovative concepts

Breast cancer (BC) epidemic is recognised now worldwide as the reality of the early twenty-first century. Increasing trends in the postmenopausal BC prevalence, even for the European countries earlier demonstrating relatively stable incidence rates of the disease, are highly alarming for the healthcare givers. This new actuality requires a substantial revision of the paradigm currently applied to the BC management and creation of highly innovative concepts. Current multi-centred study highlights new complex mechanisms of the development and progression of the postmenopausal BC. Innovative concepts are presented which argue for more effective predictive and preventive approaches well justified in view of the clusters of the symptoms analysed here and demonstrated as highly prevalent in the postmenopausal breast cancer versus BC-free individuals. Another conceptual novelty presented here is a new interpretation of the "Seed and Soil" theory of metastasis in BC. According to the new concept, the "pre-metastatic niches" ("Soil") are created by a systemic hypoxia a long time before the breast malignancy is clinically manifested.

Feeling cold and other underestimated symptoms in breast cancer: anecdotes or individual profiles for advanced patient stratification?

Breast cancer (BC) epidemic is recognised as being characteristic for the early twenty-first century. BC is a multifactorial disease, and a spectrum of modifiable (preventable) factors significantly increasing risks has been described. This article highlights a series of underestimated symptoms for consequent BC risk assessment and patient stratification. Phenomena of the deficient thermoregulation, altered sensitivity to different stimuli (pain, thirst, smell, light, stress provocation), dehydration, altered circadian and sleep patterns, tendency towards headache, migraine attacks and dizziness, as well as local and systemic hypoxic effects are discussed for BC patients providing functional links and proposing new approaches in the overall BC management.

Migraine and breast cancer risk: a meta-analysis of observational studies based on MOOSE compliant

It has long been speculated that migraine may contribute to an increased risk of breast cancer; however, results from previous studies have been inconclusive. To definitively interrogate this issue, we performed a meta-analysis to assess the correlation between these 2 diseases.Medline and PubMed were searched to identify relevant studies that had been published until October 2015. Based on a random effects model, relative risk (RR) and the corresponding 95% confidence interval (CI) were used to evaluate the pooled risk.A total of 7 studies involving 17,776 cases and 162,954 participants were included. Our study revealed that there was an inverse relationship between migraine and total breast cancer risk, with RR (95%CI) was 0.78 (0.66, 0.92). In subgroup-analysis, such an inverse relationship was also identified in the ductal and lobular carcinoma, case-control studies, and the ER/PR breast cancer. Little evidence indicative of a publication bias was uncovered.In conclusion, our study implicates a statistically significant inverse association between migraine and the risk of breast cancer. However, larger prospective cohort studies concerning other geographic populations to assess the association between migraine and the breast cancer risk are warranted.

Migraine and possible etiologic heterogeneity for hormone-receptor-negative breast cancer

Migraine headache is often timed with the menstrual cycle. Some studies have reported reduced risk of breast cancer in migraineurs but most of those did not distinguish menstrually-related from non-menstrually-related migraine. To examine the possible associations between breast cancer and migraine overall and between cancer subcategories and the two migraine subtypes, we used a cohort study of 50,884 women whose sister had breast cancer and a sister-matched case-control study including 1,418 young-onset (<50 years) breast cancer cases. We analyzed the two studies individually and also in tandem via a hybrid Cox model, examining subcategories of breast cancer in relation to menstrually-related and non-menstrually-related migraine. History of migraine was not associated with breast cancer overall. Migraine showed an inverse association with ductal carcinoma in situ (HR = 0.77; 95% CI (0.62,0.96)). Also, women with non-menstrually-related migraine had increased risk (HR = 1.30, 95% CI (0.93,1.81)) while women with menstrually-related migraine had decreased risk (HR = 0.63, 95% CI (0.42,0.96)) of hormone-receptor-negative (ER-/PR-) cancer, with a significant contrast in estimated effects (P = 0.005). While replication of these subset-based findings will be needed, effect specificity could suggest that while migraine has little overall association with breast cancer, menstrual migraine may be associated with reduced risk of ER-/PR- breast cancer.

Evaluation of relationship between breast cancer and migraine

BACKGROUND

Frequency of migraine changes at different times of a woman's reproductive cycle because of fluctuation of estrogen levels. Breast cancer has also a link with hormonal changes. Given this fact that both migraine and breast cancer are affected by estrogen, the prevalence of migraine may be different in breast cancer patients compared to the normal population.

MATERIALS AND METHODS

In this case-control study, two groups of women with and without breast cancer were compared regarding the prevalence of migraine. Each group consisted of 400 women. The diagnosis of different types of headache was made based on The International Headache Society (IHS) guidelines. Type of headache, type and receptor status of breast cancer, as well as history of taking hormonal medications was recorded. Independent t-test and Chi-square tests were used for data analysis.

RESULTS

Relative frequency of migraine headache in the normal woman was 38% compared to 19% in the breast cancer group (P < 0.0001). Tension headache was also significantly more prevalent in the normal group (P < 0.001). The frequency of migraine was significantly lower in estrogen receptor (ER)+/progesterone receptor (PR)- women compared to ER-/PR+ (26 and 43 women, respectively; P = 0.04); however, this difference was not significant for tension headache (P = 0.68).

CONCLUSION

This study confirmed the lower frequency of migraine, as well as tension headache, in breast cancer sufferers. This could be contributed to several non-hormonal factors, such as a history of long term use of nonsteroidal anti-inflammatory drugs (NSAIDs), and hormonal factors, although only migraine showed a strong link with hormone status.

Migraine and breast cancer risk: a prospective cohort study and meta-analysis

BACKGROUND

The evidence for an association between migraine and breast cancer risk is inconclusive. While female sex hormones have been proposed as one underlying mechanism, data on sex hormone levels in migraineurs are sparse.

METHODS

We prospectively evaluated the association between migraine and breast cancer risk among 115378 Nurses' Health Study II participants using Cox proportional hazards models. Differences in endogenous sex hormone levels according to migraine status were assessed among 2034 premenopausal women using linear regression. We performed a meta-analysis of studies investigating the association between migraine and invasive breast cancer risk published through October 2013. All statistical tests were two-sided.

RESULTS

Seventeen thousand six hundred ninety-six women (15.3%) reported a physician's diagnosis of migraine at baseline. Over 20 years of follow-up, 833 in situ and 3091 invasive breast malignancies occurred. Migraine was not associated with total (hazard ratio [HR] = 0.96, 95% confidence interval [CI] = 0.88 to 1.04), in situ (HR = 0.97, 95% CI = 0.82 to 1.15), or invasive breast cancer risk (HR = 0.95, 95% CI = 0.87 to 1.04). Endogenous sex hormone levels did not differ according to migraine status. In the meta-analysis, migraine was associated with a lower risk of breast cancer overall (pooled risk ratio [RR] = 0.84, 95% CI = 0.73 to 0.98). However, this inverse association was apparent only among case-control studies (pooled RR = 0.72, 95% CI = 0.66 to 0.79), and not among cohort studies (pooled RR = 0.98, 95% CI = 0.87 to 1.10).

CONCLUSION

In this large cohort study, migraine was not associated with breast cancer risk or differences in endogenous sex hormone levels. While case-control studies suggest an inverse association between migraine and breast cancer risk, prospective cohort studies do not support an association in pooled analyses.

The risk of breast cancer associated with specific patterns of migraine history

PURPOSE

Studies have suggested that a history of migraines may be associated with a lower risk of some types of breast cancer, though biological mechanisms are unclear. Identifying specific characteristics of migraines which are most strongly associated with breast cancer risk could improve our understanding of this relationship.

METHODS

We ascertained specific characteristics of women's migraine histories (severity, timing features, and presence of migraine aura). We used polytomous logistic regression to estimate the risk of ER+ ductal, ER- ductal, ER+ lobular, and ER+ ductal-lobular breast cancer associated with self-reported characteristics of migraine history. A total of 715 breast cancer cases (276 ER+ ductal, 46 ER- ductal, 191 ER+ lobular, and 202 ER+ ductal-lobular) and 376 controls ages 55-74 years were included in this population-based case-control study.

RESULTS

Compared to women without a migraine history, women with a >30-year history of migraines had a 60 % (95 % CI 0.2-0.6) lower risk of ER+ ductal breast cancer; those who had their first migraine before age 20 had 50 % lower risks of ER+ ductal and ER+ lobular breast cancer (both 95 % CIs 0.3-0.9), and women who experienced migraine with aura had 30 % (95 % CI 0.5-0.98) and 40 % (95 % CI 0.4-0.9) lower risks of ER+ ductal and ER+ lobular breast cancer, respectively.

CONCLUSION

The lower risk of ER+ breast cancer associated with migraine appears to be limited to those women with early onset or long duration of migraine history, or those who experienced migraine with aura. This expands our understanding of the relationship between migraine and breast cancer and provides additional insight into potential underlying biological mechanisms.

Migraine and subsequent risk of breast cancer: a prospective cohort study

PURPOSE

Previous studies have suggested that migraineurs are at decreased risk for developing breast cancer. Further prospective studies are warranted to confirm these results. In addition, studies evaluating migraine characteristics (e.g., migraine subtypes and frequency) are lacking.

METHODS

We conducted a prospective cohort study among 39,696 participants in the Women's Health Study who were 45 years and older at study entry. Information on migraine was self-reported with good validation rates. Incident breast cancer cases were confirmed by medical record review. We distinguished the following major endpoints: any breast cancer, a combined endpoint of invasive and in situ cases, in situ breast cancer only, and invasive breast cancer only. Cox proportional hazards models were used to calculate age- and multivariable-adjusted hazard ratios (HRs) and 95 % confidence intervals (95 % CI).

RESULTS

A total of 7,318 (18.4 %) women reported any migraine. During a mean follow-up time of 13.6 years, 432 in situ and 1,846 invasive breast cancer cases occurred. Migraine was not associated with breast cancer risk. The multivariable-adjusted HRs (95 % CI) were 1.10 (0.99-1.22) for any breast cancer, 1.06 (0.83-1.35) for in situ breast cancer, and 1.11 (0.99-1.25) for invasive breast cancer. The risk for developing breast cancer differed according to hormone receptor status with a suggestion of increased risks for hormone receptor negative tumors (HR ER-/PR- : 1.28, 95 % CI: 0.96-1.71). We did not observe meaningful differences with regard to histologic subtype or according to migraine aura status or migraine attack frequency.

CONCLUSIONS

Results of our study do not support the hypothesis that migraineurs have a decreased risk for breast cancer.

Migraine history, nonsteroidal anti-inflammatory drug use, and risk of postmenopausal endometrial cancer

Endometrial cancer is primarily a hormonally mediated disease. As such, factors that mediate or reflect exposure to estrogens, or that mediate response to such exposure, may plausibly be associated with endometrial cancer risk. History of migraines, another hormonally mediated condition, has recently been associated with a reduced risk of hormone receptor-positive breast cancer; however, the relationship between migraines and endometrial cancer has not previously been explored. We evaluated the relationship between migraine history and endometrial cancer risk in postmenopausal women, considering also the potential impact of nonsteroidal anti-inflammatory drug (NSAID) use, given the relationship of NSAIDs to hormones and to migraine history. We identified 93,384 women participating in the Women's Health Initiative prospective cohort who had an intact uterus at the time of study entry. Using Cox proportional hazards regression, we assessed risk of endometrial cancer during study follow-up according to history of migraines and according to current NSAID use at the time of study entry, adjusting for age, study arm, race, and hormone therapy use. We also evaluated interaction in these associations by body mass index. Having a history of migraines was not associated with endometrial cancer risk [hazard ratio (HR) = 0.91, 95% confidence interval (CI) = 0.75-1.11], regardless of body mass index (BMI) or NSAID use status. Similarly, current NSAID use was not associated with endometrial cancer risk (HR = 1.01, 95% CI = 0.88-1.16), regardless of BMI. Migraine history and NSAID use do not appear to be associated with risk of endometrial cancer.

Analgesic use and sex steroid hormone concentrations in postmenopausal women

Prior epidemiologic studies suggest that regular use of analgesics may decrease risk of breast and ovarian cancer. We explored possible hormone-mediated mechanisms for these associations by examining the relationship between use of aspirin, nonaspirin nonsteroidal anti-inflammatory drugs (NSAID), and acetaminophen and sex steroid hormone concentrations among 740 postmenopausal women in the Nurses' Health Study. All women reported their analgesic use in 1988 or 1990 and provided a blood sample in 1989 to 1990. We calculated adjusted geometric mean estrogen and androgen levels for each category of analgesic use and calculated the P value for trend with increasing frequency of use. There was no association between days of use per month of aspirin, nonaspirin NSAIDs, or acetaminophen in 1990 and hormone levels (all P(trend) > or = 0.09). However, we observed significant inverse trends between the estimated number of aspirin tablets per month in 1988 and concentrations of estrone (P(trend) = 0.04) and estrone sulfate (P(trend) = 0.03). In analyses of total (aspirin and nonaspirin) NSAID use in 1990, women who used NSAIDs at least 15 days per month had significantly lower levels of estradiol compared with women with no NSAID use (P(trend) = 0.03). Frequency of use of all analgesics (aspirin, nonaspirin NSAIDs, and acetaminophen) in 1990 was inversely associated with concentrations of estradiol (P(trend) = 0.001), free estradiol (P(trend) = 0.01), estrone sulfate (P(trend) = 0.03), and the ratio of estradiol to testosterone (P(trend) = 0.04). Among postmenopausal women, regular users of aspirin and other analgesics may have lower estrogen levels than nonusers, which could contribute to a decreased risk of breast or ovarian cancer among analgesic users.

Migraine history and breast cancer risk among postmenopausal women

PURPOSE Both migraine and breast cancer are hormonally mediated. Two recent reports indicate that women with a migraine history may have a lower risk of postmenopausal breast cancer than those who never suffered migraines. This finding requires confirmation; in particular, an assessment of the influence of use of nonsteroidal anti-inflammatory drugs (NSAID) is needed, because many studies indicate that NSAID use also may confer a reduction in breast cancer risk. METHODS We assessed the relationship between self-reported history of migraine and incidence of postmenopausal breast cancer in 91,116 women enrolled on the Women's Health Initiative Observational Study prospective cohort from 1993 to 1998 at ages 50 to 79 years. Through September 15, 2005, there were 4,006 eligible patients with breast cancer diagnosed. Results Women with a history of migraine had a lower risk of breast cancer (hazard ratio [HR], 0.89; 95% CI, 0.80 to 98) than women without a migraine history. This risk did not vary by recent NSAID use. The lower risk was somewhat more pronounced for invasive estrogen-receptor-positive and progesterone-receptor-positive tumors (HR, 0.83; 95% CI, 0.71 to 0.97), as no reduction in risk was observed for invasive ER-negative/PR-negative tumors (HR, 1.16; 95% CI, 0.86 to 1.57), and this difference in risk estimates was borderline statistically significant (P = .06). CONCLUSION This study supports the hypothesis that a history of migraine is associated with a lower risk of breast cancer and that this relationship is independent of recent NSAID use.

Resolution of menstrually related migraine following aggressive treatment for breast cancer

Hormonal influences associated with the female menstrual cycle play strong roles in both migraine and particular types of breast cancer, but there is limited literature on the effects of breast cancer treatment regimens in women with migraine. The present case describes resolution of menstrually related migraine following aggressive treatment for infiltrating ductal carcinoma (neoadjuvant chemotherapy, single radical mastectomy, and locoregional radiation therapy) that was maintained with supplemental treatment using tamoxifen, an anti-estrogenic agent. This novel case is presented to stimulate further research into the hormonal mechanisms underlying migraine.

Relationship between migraine history and breast cancer risk among premenopausal and postmenopausal women

Both migraine and breast cancer are hormonally mediated diseases, and it is biologically plausible that women with a history of migraine may have a reduced breast cancer risk. However, this relationship has only been assessed in a single relatively small study that was unable to assess the effect of migraine triggers, which are also well-established breast cancer risk factors (e.g., use of alcohol and exogenous hormones), on the inverse association observed. Utilizing data on 4,568 breast cancer cases and 4,678 controls who participated in a multicenter population-based case-control study in the United States, we evaluated the association between migraine history and breast cancer risk using unconditional logistic regression. Migraine history data were obtained from structured in-person interviews. Women with a history of migraine had a reduced risk of breast cancer [odds ratio, 0.74; 95% confidence interval (CI), 0.66-0.82]. This risk did not differ by menopausal status, age at migraine diagnosis, use of prescription migraine medications, or when analyses were restricted to women who avoided various migraine triggers (including alcohol, exogenous hormones, and smoking). These data support a previous finding that a history of migraine may be associated with a reduced risk of breast cancer. It extends the prior report in observing that this relationship holds for both premenopausal and postmenopausal women and is independent of exposure to common migraine triggers.