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.

Depression, anxiety, psychotropic drugs, and acute myocardial infarction: large prospective study of United Kingdom women

BACKGROUND

Reported associations between depression and myocardial infarction in some studies might be explained by use of psychotropic drugs, residual confounding, and/or reverse causation (whereby heart disease precedes depression). We investigated these hypotheses in a large prospective study of UK women with no previous vascular disease.

METHODS

At baseline in median year 2001 (IQR 2001-2003), Million Women Study participants reported whether or not they were currently being treated for depression or anxiety, their self-rated health, and medication use during the previous 4 weeks. Follow-up was through linkage to national hospital admission and mortality databases. Cox regression yielded adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the first myocardial infarction event in those reporting treatment for depression or anxiety (subdivided by whether or not the treatment was with psychotropic drugs) v. not, and stratified by self-reported health and length of follow-up.

RESULTS

During mean follow-up of 13.9 years of 690 335 women (mean age 59.8 years) with no prior heart disease, stroke, transient ischaemic attack, or cancer, 12 819 had a first hospital admission or death from myocardial infarction. The aHRs for those reporting treatment for depression or anxiety with, and without, regular use of psychotropic drugs were 0.96 (95% CI 0.89-1.03) and 0.99 (0.89-1.11), respectively. No associations were found separately in women who reported being in good/excellent or poor/fair health or by length of follow-up.

CONCLUSION

The null findings in this large prospective study are consistent with depression not being an independent risk factor for myocardial infarction.

Cellular Telephone Use and the Risk of Brain Tumors: Update of the UK Million Women Study

BACKGROUND

The ongoing debate of whether use of cellular telephones increases the risk of developing a brain tumor was recently fueled by the launch of the fifth generation of wireless technologies. Here, we update follow-up of a large-scale prospective study on the association between cellular telephone use and brain tumors.

METHODS

During 1996-2001, 1.3 million women born in 1935-1950 were recruited into the study. Questions on cellular telephone use were first asked in median year 2001 and again in median year 2011. All study participants were followed via record linkage to National Health Services databases on deaths and cancer registrations (including nonmalignant brain tumors).

RESULTS

During 14 years follow-up of 776 156 women who completed the 2001 questionnaire, a total of 3268 incident brain tumors were registered. Adjusted relative risks for ever vs never cellular telephone use were 0.97 (95% confidence interval = 0.90 to 1.04) for all brain tumors, 0.89 (95% confidence interval = 0.80 to 0.99) for glioma, and not statistically significantly different to 1.0 for meningioma, pituitary tumors, and acoustic neuroma. Compared with never-users, no statistically significant associations were found, overall or by tumor subtype, for daily cellular telephone use or for having used cellular telephones for at least 10 years. Taking use in 2011 as baseline, there were no statistically significant associations with talking for at least 20 minutes per week or with at least 10 years use. For gliomas occurring in the temporal and parietal lobes, the parts of the brain most likely to be exposed to radiofrequency electromagnetic fields from cellular telephones, relative risks were slightly below 1.0.

CONCLUSION

Our findings support the accumulating evidence that cellular telephone use under usual conditions does not increase brain tumor incidence.

Body size in early life and the risk of postmenopausal breast cancer

BACKGROUND

Greater early life adiposity has been reported to reduce postmenopausal breast cancer risk but it is unclear whether this association varies by tumour characteristics. We aimed to assess associations of early life body size with postmenopausal breast cancer and its subtypes, allowing for body size at other ages.

METHODS

A total of 342,079 postmenopausal UK women who reported their body size at age 10, clothes size at age 20, and body mass index (BMI) at baseline (around age 60) were followed by record linkage to national databases for cancers and deaths. Cox regression yielded adjusted relative risks (RRs) of breast cancer, overall and by tumour subtype, in relation to body size at different ages.

RESULTS

During an average follow-up of 14 years, 15,506 breast cancers were diagnosed. After adjustment for 15 potential confounders, greater BMI at age 60 was associated with an increased risk of postmenopausal breast cancer (RR per 5 kg/m2=1.20, 95%CI 1.18-1.22) whereas greater adiposity in childhood and, to a lesser extent, early adulthood, was associated with a reduced risk (0.70, 0.66-0.74, and 0.92, 0.89-0.96, respectively). Additional adjustment for midlife BMI strengthened associations with BMI at both age 10 (0.63, 0.60-0.68) and at age 20 (0.78, 0.75-0.81). The association with midlife adiposity was confined to hormone sensitive subtypes but early life adiposity had a similar impact on the risk of all subtypes.

CONCLUSION

Early life and midlife adiposity have opposite effects on postmenopausal breast cancer risk and the biological mechanisms underlying these associations are likely to differ.

Ovarian cancer survival by stage, histotype, and pre-diagnostic lifestyle factors, in the prospective UK Million Women Study

BACKGROUND

Ovarian cancer is the fifth leading cause of cancer mortality in UK women. Ovarian cancer survival varies by disease stage at diagnosis, but evidence is mixed on the effect of tumour histological type (histotype) and other factors.

METHODS

1.3 million UK women completed a detailed health questionnaire in 1996-2001 and were followed for incident cancers and deaths via linkage to national databases. Using Cox regression models, we estimated adjusted relative risks (RRs) of death from ovarian cancer, by stage at diagnosis, tumour histotype, and 16 other personal characteristics of the women.

RESULTS

During 17.7 years' average follow-up, 13,222 women were diagnosed with ovarian cancer, and 8697 of them died from the disease. Stage at diagnosis was a major determinant of survival (stage IV vs I, RR=10.54, 95% CI: 9.16-12.13). Histotype remained a significant predictor after adjustment for stage and other factors, but associations varied over the follow-up period. Histotype-specific survival was worse for high-grade than low-grade tumours. Survival appeared worse with older age at diagnosis (per 5 years: RR=1.19, 95% CI: 1.15-1.22), higher BMI (per 5-unit increase: RR=1.06, 95% CI: 1.02-1.11), and smoking (current vs never: RR=1.17, 95% CI: 1.07-1.27), but there was little association with 13 other pre-diagnostic reproductive, anthropometric, and lifestyle factors.

CONCLUSION

Stage at diagnosis is a strong predictor of ovarian cancer survival, but tumour histotype and grade remain predictors of survival even after adjustment for stage and other factors, contributing further evidence of biological dissimilarity between the ovarian cancer histotypes. Obesity and smoking represent potentially-modifiable determinants of survival, but the stronger association with stage suggests that improving earlier diagnosis would have a greater impact on increasing ovarian cancer survival.

Detailed breast cancer pathology data for large-scale studies - access and completeness in NSW, Australia

OBJECTIVES

We sought to determine the ease with which breast cancer pathology data could be ascertained for a large cohort of Australian women, to support epidemiological research.

METHOD

We assessed a range of options for accessing breast cancer pathology data. Manual review of the pathology report provided to the New South Wales Cancer Registry (NSWCR) was considered most feasible, complete and reliable. Incident breast cancers (ICD-10 C50) in female 45 and Up Study participants, resident in NSW, were identified from linked NSWCR data for the period 2006-2012. Data not routinely available in the NSWCR, including hormone receptor status, were extracted from the pathology report provided to the registry.

RESULTS

Among 143 079 eligible women, 2051 had a first registration of breast cancer following cohort recruitment. The mean age at cancer diagnosis was 64.5 years. Based on cancer registry data, the cancers were predominantly ductal (74.1%), 54.4% were localised to the breast at diagnosis and 24.2% were >50 mm in size. Based on manually extracted data from pathology records, 23.9% of cancers were histological grade 1, 79.6% were oestrogen receptor positive and 71.2% were progestogen receptor positive. These data were mostly complete (<10% missing). HER2 receptor status was less well reported, with 31.9% of cancers having indeterminate or missing data, while 11.3% were reported as positive. Data on lymph node status was missing in 16.1% of breast cancer reports, 33.7% were node positive. 8.0% of breast cancers had involved surgical margins, and this data was missing for 14.1% of cases.

CONCLUSION

Pathology information, in addition to that available from routine registry data, is required both for breast cancer research and for monitoring trends in the types of breast cancer occurring over time in Australia. All the important additional data items required are recorded on the pathology report, which is provided to the NSWCR as part of cancer notification but is not routinely coded, and are generally fairly complete. However, access to these data for large-scale studies requires substantial effort. Coding the pathology data and making it routinely available would substantially improve cancer research and enable proper monitoring of breast cancer trends in Australia.

282Social isolation and incident coronary heart disease in two large UK prospective studies

Background

Social isolation is associated with CHD mortality but evidence of association with incident CHD is mixed. We prospectively examined this association in the Million Women Study (MWS) and UK Biobank (UKB).

Methods

481,946 MWS and 456,612 UKB participants reported on social isolation (living alone, little contact with family/friends/groups). Excluding those reporting previous CHD or stroke, participants were followed for incident CHD using linkage to hospital admission and death records. Cox regression yielded relative risks (RR) by 3 levels of social isolation, adjusted for relevant confounders.

Results

During 7 years follow-up in the MWS and UKB, there were 42,402 first coronary heart disease events in total (of which 1,834 were fatal without an associated hospital admission). After adjustment, social isolation was not associated with hospital admission for first CHD events (combined RR for both studies: RR = 1.01, 95% CI: 0.98–1.04). However, the risk of fatal first CHD events without an associated hospital admission was substantially higher in the most isolated group than the least isolated group (1.86 [1.63–2.12]) This association with fatal first CHD events was driven by the association with living alone.

Conclusions

Social isolation was not associated with increased risk of first CHD hospital admissions but was associated with increased risk of death from CHD.

Key messages

Social isolation is likely not a risk factor for developing CHD, but people living alone may be at greater risk of dying from a coronary event than those not living alone.

863Alcohol and cancer in an Australian cohort of 226,162 participants aged 45 years and over

Background

Australia has a relatively high level of alcohol consumption. Although alcohol consumption is known to increase the risk of several cancer types internationally, local evidence for Australia is limited.

Methods

Cox proportional hazards regressions were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for cancer risk in relation to weekly alcohol consumption among 226,162 participants aged ≥45 years (2006-2009) in the 45 and Up Study, an Australian prospective cohort study. Incident cancer cases were ascertained by linkage to the New South Wales Cancer Registry to December 2013 by the Centre for Health Record Linkage.

Results

Over a median 5.4 years, 17,332 cancers were diagnosed. Increasing levels of alcohol intake were associated with increased risk of any cancer (HR per seven drink increase in weekly consumption: 1.02; 95% CI: 1.00-1.04), and cancers of the upper aerodigestive tract (1.19;1.10-1.29), mouth/pharynx (1.18;1.08-1.29), oesophagus (1.22;1.04-1.43), colorectum (1.09;1.04-1.15), colon (1.13;1.06-1.20), liver (1.22;1.04-1.44), breast (1.09;1.00-1.18), and melanoma (1.05;1.00-1.10); whereas an inverse association was observed for thyroid cancer (0.80;0.64-1.00). We estimated that by age 85 years, Australian men and women who consume &gt;14 drinks/week increase their absolute risk of alcohol-attributable cancer by 4.4% and 5.4%, respectively, compared to non-drinkers.

Conclusions

We report relative risks of cancer incidence in relation to alcohol consumption that match the international evidence. In Australia, a nation with relatively high alcohol consumption, these risks may translate into a significant public health burden.

Key messages

We have generated estimates for the relationship between alcohol consumption and cancer risk in Australia.

SARS-CoV-2 Variants and Vaccines

Viral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based.

Social isolation and risk of heart disease and stroke: analysis of two large UK prospective studies

BACKGROUND

Social isolation has been associated with increased risk of coronary heart disease and stroke. However, it is unclear whether the associations differ between fatal and non-fatal events or by the type of isolation (living alone or having few social contacts). We aimed to examine these associations in two large UK prospective cohorts.

METHODS

Million Women Study and UK Biobank participants without previous coronary heart disease or stroke who provided data in median year 2010 (IQR 2009-2011) on social contacts were included in this prospective analysis. Participants were followed up to median year 2017 (2017-2017) by electronic linkage to national hospital and death records. Risk ratios (RRs) were calculated using Cox regression for first coronary heart disease and stroke event (overall, and separately for hospital admission as the first event and for death without an associated hospital admission as the first event) by three levels of social isolation (based on living alone, contact with family or friends, and group participation) adjusted for age, sex, study, region, deprivation, smoking, alcohol intake, body-mass index, physical activity, and self-rated health.

FINDINGS

938 558 participants were included in our analyses (mean age 63 years [SD 9]): 481 946 participants from the Million Women Study (mean age 68 years [5]) and 456 612 participants (mean age 57 years [8]) from UK Biobank. During a mean follow-up period of 7 years (2), 42 402 first coronary heart disease events (of which 1834 were fatal without an associated hospital admission) and 19 999 first stroke events (of which 529 were fatal without an associated hospital admission) occurred. Little, if any, association was found between social isolation and hospital admission for a first coronary heart disease or stroke event (combined RR for both studies 1·01 [95% CI 0·98-1·04] for coronary heart disease and 1·13 [1·08-1·18] for stroke, when comparing the most isolated group with the least isolated group). However, the risk of death without an associated hospital admission was substantially higher in the most isolated group than the least isolated group for coronary heart disease (1·86 [1·63-2·12]) and stroke (1·91 [1·48-2·46]). For coronary heart disease or stroke death as the first event, RRs were substantially higher (test for heterogeneity, p=0·002) for participants living alone versus those not living alone (1·60 [1·46-1·75]) than for those with fewer versus more contact with family, friends, or groups (1·27 [1·16-1·38]). These findings did not differ greatly between studies, or by self-rated health.

INTERPRETATION

Social isolation seems to have little direct effect on the risk of developing a first coronary heart disease or stroke. By contrast, social isolation substantially increases the risk that the first such event is fatal before reaching hospital, particularly among people who live alone, perhaps because of the absence of immediate help in responding to an acute heart attack or stroke.

FUNDING

UK Medical Research Council, Cancer Research UK.

Sleep duration and breast cancer incidence: results from the Million Women Study and meta-analysis of published prospective studies

STUDY OBJECTIVES

To investigate the association between sleep duration and breast cancer incidence, we examined the association in a large UK prospective study and conducted a meta-analysis of prospective studies.

METHODS

In the Million Women Study, usual sleep duration over a 24-h period was collected in 2001 for 713,150 participants without prior cancer, heart problems, stroke, or diabetes (mean age = 60 years). Follow-up for breast cancer was by record linkage to national cancer registry data for 14.3 years on average from the 3-year resurvey. Cox regression models yielded multivariable-adjusted breast cancer relative risks (RR) and 95% confidence intervals (CIs) for sleep duration categories. Published prospective studies of sleep duration and breast cancer risk were included in a meta-analysis, which estimated the inverse-variance weighted average of study-specific log RRs for short and for long versus average duration sleep.

RESULTS

After excluding the first 5 years to minimize reverse causation bias in the Million Women Study, 24,476 women developed breast cancer. Compared with 7-8 h of sleep, the RRs for <6, 6, 9, and >9 h of sleep were 1.01 (95% CI, 0.95-1.07), 0.99 (0.96-1.03), 1.01 (0.96-1.06), and 1.03 (0.95-1.12), respectively. In a meta-analysis of 14 prospective studies plus the Million Women Study, including 65,410 breast cancer cases, neither short (RR < 7 h = 0.99 [0.98-1.01]) nor long (RR > 8 h = 1.01 [0.98-1.04]) versus average duration sleep was associated with breast cancer risk.

CONCLUSIONS

The totality of the prospective evidence does not support an association between sleep duration and breast cancer risk.

Cognitive and social activities and long-term dementia risk: the prospective UK Million Women Study

BACKGROUND

Although dementia is associated with non-participation in cognitive and social activities, this association might merely reflect the consequences of dementia, rather than any direct effect of non-participation on the subsequent incidence of dementia. Because of the slowness with which dementia can develop, unbiased assessment of any such direct effects must relate non-participation in such activities to dementia detection rates many years later. Prospective studies with long-term follow-up can help achieve this by analysing separately the first and second decade of follow-up. We report such analyses of a large, 20-year study.

METHODS

The UK Million Women Study is a population-based prospective study of 1·3 million women invited for National Health Service (NHS) breast cancer screening in median year 1998 (IQR 1997-1999). In median year 2001 (IQR 2001-2003), women were asked about participation in adult education, groups for art, craft, or music, and voluntary work, and in median year 2006 (IQR 2006-2006), they were asked about reading. All participants were followed up through electronic linkage to NHS records of hospital admission with mention of dementia, the first mention of which was the main outcome. Comparing non-participation with participation in a particular activity, we used Cox regression to assess fully adjusted dementia risk ratios (RRs) during 0-4, 5-9, and 10 or more years, after information on that activity was obtained.

FINDINGS

In 2001, 851 307 women with a mean age of 60 years (SD 5) provided information on participation in adult education, groups for art, craft, or music, and voluntary work. After 10 years, only 9591 (1%) had been lost to follow-up and 789 339 (93%) remained alive with no recorded dementia. Follow-up was for a mean of 16 years (SD 3), during which 31 187 (4%) had at least one hospital admission with mention of dementia, including 25 636 (3%) with a hospital admission with dementia mentioned for the first time 10 years or more after follow-up began. Non-participation in cognitive or social activities was associated with higher relative risks of dementia detection only during the first decade after participation was recorded. During the second decade, there was little association. This was true for non-participation in adult education (RR 1·04, 99% CI 0·98-1·09), in groups for art, craft, or music (RR 1·04, 0·99-1·09), in voluntary work (RR 0·96, 0·92-1·00), or in any of these three (RR 0·99, 0·95-1·03). In 2006, 655 118 women provided information on reading. For non-reading versus any reading, there were similar associations with dementia, again with strong attenuation over time since reading was recorded, but longer follow-up is needed to assess this reliably.

INTERPRETATION

Life has to be lived forwards, but can be understood only backwards. Long before dementia is diagnosed, there is a progressive reduction in various mental and physical activities, but this is chiefly because its gradual onset causes inactivity and not because inactivity causes dementia.

FUNDING

UK Medical Research Council, Cancer Research UK.

Health impacts and environmental footprints of diets that meet the Eatwell Guide recommendations: analyses of multiple UK studies

OBJECTIVES

To assess the health impacts and environmental consequences of adherence to national dietary recommendations (the Eatwell Guide (EWG)) in the UK.

DESIGN AND SETTING

A secondary analysis of multiple observational studies in the UK.

PARTICIPANTS

Adults from the European Prospective Investigation into Cancer - Oxford(EPIC-Oxford), UK Biobank and Million Women Study, and adults and children aged 5 and over from the National Diet and Nutrition Survey (NDNS).Primary and secondary outcome measures risk of total mortality from Cox proportional hazards regression models, total greenhouse gas emissions (GHGe) and blue water footprint (WF) associated with 'very low' (0-2 recommendations), 'low' (3-4 recommendations) or 'intermediate-to-high' (5-9 recommendations) adherence to EWG recommendations.

RESULTS

Less than 0.1% of the NDNS sample adhere to all nine EWG recommendations and 30.6% adhere to at least five recommendations. Compared with 'very low' adherence to EWG recommendations, 'intermediate-to-high adherence' was associated with a reduced risk of mortality (risk ratio (RR): 0.93; 99% CI: 0.90 to 0.97) and -1.6 kg CO2eq/day (95% CI: -1.5 to -1.8), or 30% lower dietary GHGe. Dietary WFs were similar across EWG adherence groups. Of the individual Eatwell guidelines, adherence to the recommendation on fruit and vegetable consumption was associated with the largest reduction in total mortality risk: an RR of 0.90 (99% CI: 0.88 to 0.93). Increased adherence to the recommendation on red and processed meat consumption was associated with the largest decrease in environmental footprints (-1.48 kg CO2eq/day, 95% CI: -1.79 to 1.18 for GHGe and -22.5 L/day, 95% CI: -22.7 to 22.3 for blue WF).

CONCLUSIONS

The health and environmental benefits of greater adherence to EWG recommendations support increased government efforts to encourage improved diets in the UK that are essential for the health of people and the planet in the Anthropocene.

Alcohol intake and Parkinson's disease risk in the million women study

BACKGROUND

Alcohol intake may be associated with a lower risk of Parkinson's disease (PD), but findings from previous studies have been inconclusive.

OBJECTIVE

To determine the association between alcohol intake and PD risk in the Million Women Study, a large, prospective study of women in the UK.

METHODS

Between 1996 and 2001, approximately 1.3 million women in the UK, mean age 56 (standard deviation, 5) years, were recruited into the Million Women Study. Information on alcohol intake, lifestyle factors, and medical history was collected at recruitment by questionnaire. Information on incident cases of PD was ascertained by record linkage to national hospital admission records and death registrations. We estimated multivariable-adjusted relative risks and corresponding 95% confidence intervals using Cox proportional hazards models according to categories of alcohol intake.

RESULTS

During an average of 17.9 years of follow-up, 11,009 women had a new record of PD among 1,309,267 women. In drinkers, the multivariable-adjusted relative risk comparing women who drank more than 14 drinks of alcohol per week with women who drank 1 to 2 drinks of alcohol per week was 0.99 (95% confidence interval: 0.90, 1.10). Results did not materially change after excluding the first 10 years of follow-up (relative riskadjusted = 1.01; 95% confidence interval: 0.90, 1.13). There were no significant trends in alcohol-related PD risk among never smokers. Additionally, examining this association by type of alcohol intake also yielded null findings.

CONCLUSION

These results do not support an association between alcohol intake and PD risk in women. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

The Associations Between Seven Different Types of Physical Activity and the Incidence of Fracture at Seven Sites in Healthy Postmenopausal UK Women

There is a paucity of information on associations between specific types of physical activity and fracture risk at different sites in otherwise healthy postmenopausal women. Therefore, we examined risk of fracture at seven different sites associated with seven different types of physical activity in the population-based prospective UK Million Women Study. A total of 371,279 postmenopausal women (mean age 59.8 years), rating their health as good or excellent and reporting participation in walking, cycling, gardening, doing housework, yoga, dance, and sports club activities, were followed for site-specific incident fracture through record linkage to national databases on day-case and overnight hospital admissions. Cox regression yielded adjusted relative risks (RRs) and, because of the large number of statistical tests done, 99% confidence intervals (CIs) for fracture at seven different sites in relation to seven different physical activities. During an average follow-up of 12 years, numbers with a first site-specific fracture were as follows: humerus (2341), forearm (1238), wrist (7358), hip (4354), femur (not neck) (617), lower leg (1184), and ankle (3629). For upper limb fractures there was significant heterogeneity across the seven activity types (test for heterogeneity p = 0.004), with gardening more than 1 hour/week associated with a lower risk (RR = 0.91; 99% CI, 0.86 to 0.96; p < 0.0001), whereas cycling more than 1 hour/week was associated with an increased risk (RR = 1.11; 99% CI, 1.00 to 1.23; p = 0.008). For fractures of the lower limb (including hip) there was no significant heterogeneity by type of activity, with significant approximately 5% to 15% reductions in risk associated with most activities, except cycling. For hip fractures, there was no significant heterogeneity by type of activity, but with significant 15% to 20% reductions in risk associated with walking for 1 hour/day and participating in yoga and sporting activities. Physical activity is a modifiable risk factor for fracture, but the effects differ between different types of activities and different fracture sites. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Body mass index, diet, physical inactivity, and the incidence of dementia in 1 million UK women

OBJECTIVE

To help determine whether midlife obesity is a cause of dementia and whether low body mass index (BMI), low caloric intake, and physical inactivity are causes or merely consequences of the gradual onset of dementia by recording these factors early in a large 20-year prospective study and relating them to dementia detection rates separately during follow-up periods of <5, 5 to 9, 10 to 14, and 15+ years.

METHODS

A total of 1,136,846 UK women, mean age 56 (SD 5) years, were recruited in 1996 to 2001 and asked about height, weight, caloric intake, and inactivity. They were followed up until 2017 by electronic linkage to National Health Service records, detecting hospital admissions with mention of dementia. Cox regression yielded adjusted rate ratios (RRs) for first dementia detection during particular follow-up periods.

RESULTS

Fifteen years after the baseline survey, only 1% were lost to follow-up, and 89% remained alive with no detected dementia, of whom 18,695 had dementia detected later, at a mean age of 77 (SD 4) years. Dementia detection during years 15+ was associated with baseline obesity (BMI 30+ vs 20-24 kg/m2: RR 1.21, 95% confidence interval 1.16-1.26, p < 0.0001) but not clearly with low BMI, low caloric intake, or inactivity at baseline. The latter 3 factors were associated with increased dementia rates during the first decade, but these associations weakened substantially over time, approaching null after 15 years.

CONCLUSIONS

Midlife obesity may well be a cause of dementia. In contrast, behavioral changes due to preclinical disease could largely or wholly account for associations of low BMI, low caloric intake, and inactivity with dementia detection during the first decade of follow-up.

Social influences on smoking cessation in mid-life: Prospective cohort of UK women

INTRODUCTION

Decisions to quit smoking are thought to be influenced by social factors such as friends, family and social groups, but there have been few attempts to examine comprehensively the influence of a range of social factors on smoking cessation. In the largest study to date, we examined whether smoking cessation was associated with marital status and the smoking habits of a partner, socio-economic status and social participation.

METHODS

In the prospective Million Women Study, 53,650 current smokers in 2001 (mean age 58.3, SD 4.4) reported their smoking status 4 years later; and reported on social factors on both occasions. Logistic regression yielded odds ratios (ORs) and 99% confidence intervals (CIs) for stopping smoking in the next 4 years by marital status, whether their partner smoked, deprivation, education, and participation in social activities.

RESULTS

31% (16,692) of the current smokers at baseline had stopped after 4 years. Smokers who were partnered at baseline were more likely to quit than those who were not partnered (OR 1.13, 99% CI 1.06-1.19). Compared to having a partner who smoked throughout, those who had a non-smoking partner throughout were more likely to quit (OR 2.01, 99% CI 1.86-2.17), and those who had a partner who smoked at baseline but stopped smoking in the next 4 years were even more likely to quit (OR 6.00, 5.41-6.67). There was no association with cessation for education or deprivation. The association with social participation varied by type of activity but was null overall.

CONCLUSION

Women who were partnered were most likely to stop smoking if their partner also stopped smoking. There was little evidence of a strong influence of either socio-economic status or social participation on smoking cessation. These results emphasise the importance of a spouse's smoking habits on the likelihood of a smoker successfully quitting smoking.

Body mass index in midlife and risk of attempted suicide and suicide: prospective study of 1 million UK women

BACKGROUND

High body mass index (BMI) has been associated with lower risks of suicidal behaviour and being underweight with increased risks. However, evidence is inconsistent and sparse, particularly for women. We aim to study this relationship in a large cohort of UK women.

METHODS

In total 1.2 million women, mean age 56 (s.d. 5) years, without prior suicide attempts or other major illness, recruited in 1996-2001 were followed by record linkage to national hospital admission and death databases. Cox regression yielded relative risks (RRs) and 95% confidence intervals (CIs) for attempted suicide and suicide by BMI, adjusted for baseline lifestyle factors and self-reported treatment for depression or anxiety.

RESULTS

After 16 (s.d. 3) years of follow-up, 4930 women attempted suicide and 642 died by suicide. The small proportion (4%) with BMI <20 kg/m2 were at clearly greater risk of attempted suicide (RR = 1.38, 95% CI 1.23-1.56) and suicide (RR = 2.10, 1.59-2.78) than women of BMI 20-24.9 kg/m2; p < 0.0001 for both comparisons. Small body size at 10 and 20 years old was also associated with increased risks. Half the cohort had BMIs >25 kg/m2 and, while risks were somewhat lower than for BMI 20-24.9 kg/m2 (attempted suicide RR = 0.91, 0.86-0.96; p = 0.001; suicide RR = 0.79, 0.67-0.93; p = 0.006), the reductions in risk were not strongly related to level of BMI.

CONCLUSIONS

Being underweight is associated with a definite increase in the risk of suicidal behaviour, particularly death by suicide. Residual confounding cannot be excluded for the small and inconsistent decreased risk of suicidal behaviour associated with being overweight or obese.

Coffee and pancreatic cancer risk among never-smokers in the UK prospective Million Women Study

Reported associations between coffee consumption and an increased risk of pancreatic cancer could be due to residual confounding by smoking and/or biased recall of coffee consumption in retrospective studies. Studying associations prospectively in never smokers should minimize these problems, but thus far such studies have included relatively small numbers of cases. In our study, 309,797 never-smoking women self-reported typical daily coffee consumption at a mean age of 59.5 years (SD 5.0 years) and were followed up for a median of 13.7 years (IQR: 12.2-14.9) through record linkage to national health cancer and death registries. During this period, 962 incident cases of pancreatic cancers were registered. Cox regression was used to calculate adjusted relative risks [RRs] of incident pancreatic cancer with 95% confidence intervals [CIs] in relation to coffee consumption at baseline. After adjustment for potential confounding factors, including body mass index and alcohol consumption, RRs of pancreatic cancer in never-smokers who reported usually consuming 1-2, 3-4, and ≥ 5 cups of coffee daily, compared to nondrinkers of coffee, were 1.02 (CI 0.83-1.26), 0.96 (0.76-1.22), and 0.87 (0.64-1.18), respectively (trend p = 0.2). A meta-analysis of results from this cohort and 3 smaller prospective studies found little or no statistically significant association between coffee consumption and pancreatic cancer risk in never smokers (summary RR = 1.00, CI 0.86-1.17 for ≥2 vs. zero cups of coffee per day).

Adult cancer risk in women who were breastfed as infants: large UK prospective study

There are known short-term benefits in breastfed infants versus bottle-fed infants in terms of lower risks of infection and obesity in infancy and childhood, but the long-term effect on the risk of adult cancers is unclear. In a cohort of 1 in 4 UK women born in 1935-1950 we report the incidence of adult cancers in relation to having been breastfed in infancy. In median year 2001 (interquartile range 2000-2003) 548,741 women without prior cancer reported whether they had been breastfed. There was 81% agreement between women's report of having been breastfed and information on breastfeeding recorded when they were 2 years old. Participants were followed by record-linkage to national cancer registration, hospital admission and death databases. Cox regression yielded adjusted relative risks (RRs) and 95% confidence intervals (CI) by having been breastfed or not for eight cancer sites with > 2000 incident cases and for related conditions, where appropriate. Of the eight cancers examined here one association was highly statistically significant: an increase in colorectal cancer incidence among women who had been breastfed versus not (RR 1.18, 95% CI 1.12-1.24, n = 8651). To investigate further the findings for colorectal cancer, we studied eight other gastro-intestinal conditions, and found increased risks in women who had been breastfed versus not for benign colorectal polyps (RR 1.09, 95% CI 1.05-1.13, n = 17,677) and for appendicitis (RR 1.19, 95% CI 1.07-1.31, n = 2108). The greater risks of adult colorectal cancer, colorectal polyps and appendicitis associated with having been breastfed in infancy suggest possible long-term effects of infant feeding practices on the gastrointestinal tract. Further studies are required to clarify this novel association.

Body mass index and use and costs of primary care services among women aged 55-79 years in England: a cohort and linked data study

BACKGROUND

Excess weight is associated with poor health and increased healthcare costs. There are no reliable data describing the association between BMI and the use and costs of primary care services in the United Kingdom.

METHODS

Among 69,440 participants in the Million Women Study with primary care records in the Clinical Practice Research Datalink between April 2006 (mean age 64 years) and March 2014, the annual rates and costs of their primary care consultations, prescription medications, and diagnostic and monitoring tests were estimated in relation to their self-reported body mass index (BMI) at recruitment in 1996-2001 (mean age 56 years). Associations of BMI with annual costs were projected to all women in England aged 55-79 years in 2013.

RESULTS

Over an average follow-up of 6.0 years, annual rates and mean costs were lowest for women with a BMI of 20 to <22.5 kg/m2 for consultations (7.0 consultations, 99% CI 6.8-7.1; £288, £280-£295) and prescription medications (27.0 prescribed items, 26.0-27.9; £227, £216-£237). Above 20 kg/m2, a 2 kg/m2 higher BMI (a 5 kg change in weight for a woman of average height) was associated with 5.2% (4.8-5.6) and 9.9% (9.2-10.6) higher mean annual consultation and prescription medication costs, respectively. Annual rates and mean costs of diagnostic and monitoring tests were similar for women with different BMIs. Among all women aged 55-79 years in England, excess weight accounted for an estimated 11% (£229 million/£2.2 billion) of all consultation costs and 20% (£384 million/£1.9 billion) of all prescription medication costs, of which 27% were for diabetes drugs, 19% for circulatory system drugs, and 13% for analgesics.

CONCLUSIONS

Excess body weight is associated with higher use and costs of primary care services among women in England. Reducing the prevalence of excess weight could improve the health of women and reduce pressures on primary care.

Screen-detected and interval colorectal cancers in England: Associations with lifestyle and other factors in women in a large UK prospective cohort

Faecal occult blood (FOB) - based screening programmes for colorectal cancer detect about half of all cancers. Little is known about individual health behavioural characteristics which may be associated with screen-detected and interval cancers. Electronic linkage between the UK National Health Service Bowel Cancer Screening Programme (BCSP) in England, cancer registration and other national health records, and a large on-going UK cohort, the Million Women Study, provided data on 628,976 women screened using a guaiac-FOB test (gFOBt) between 2006 and 2012. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated by logistic and Cox regression for associations between individual lifestyle factors and risk of colorectal tumours. Among screened women, 766 were diagnosed with screen-detected colorectal cancer registered within 2 years after a positive gFOBt result, and 749 with interval colorectal cancers registered within 2 years after a negative gFOBt result. Current smoking was significantly associated with risk of interval cancer (RR 1.64, 95%CI 1.35-1.99) but not with risk of screen-detected cancer (RR 1.03, 0.84-1.28), and was the only factor of eight examined to show a significant difference in risk between interval and screen-detected cancers (p for difference, 0.003). Compared to screen-detected cancers, interval cancers tended to be sited in the proximal colon or rectum, to be of non-adenocarcinoma morphology, and to be of higher stage.

Diet and risk of glioma: combined analysis of 3 large prospective studies in the UK and USA

BACKGROUND

Available evidence on diet and glioma risk comes mainly from studies with retrospective collection of dietary data. To minimize possible differential dietary recall between those with and without glioma, we present findings from 3 large prospective studies.

METHODS

Participants included 692 176 from the UK Million Women Study, 470 780 from the US National Institutes of Health-AARP study, and 99 148 from the US Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Cox regression yielded study-specific adjusted relative risks for glioma in relation to 15 food groups, 14 nutrients, and 3 dietary patterns, which were combined, weighted by inverse variances of the relative risks. Separate analyses by <5 and ≥5 years follow-up assessed potential biases related to changes of diet before glioma diagnosis.

RESULTS

The 1 262 104 participants (mean age, 60.6 y [SD 5.5] at baseline) were followed for 15.4 million person-years (mean 12.2 y/participant), during which 2313 incident gliomas occurred, at mean age 68.2 (SD 6.4). Overall, there was weak evidence for increased glioma risks associated with increasing intakes of total fruit, citrus fruit, and fiber and healthy dietary patterns, but these associations were generally null after excluding the first 5 years of follow-up. There was little evidence for heterogeneity of results by study or by sex.

CONCLUSIONS

The largest prospective evidence to date suggests little, if any, association between major food groups, nutrients, or common healthy dietary patterns and glioma incidence. With the statistical power of this study and the comprehensive nature of the investigation here, it seems unlikely we have overlooked major effects of diet on risk of glioma that would be of public health concern.

Use of oral bisphosphonates and risk of hospital admission with osteonecrosis of the jaw: Large prospective cohort study in UK women

About 1 in 10 postmenopausal UK women are currently prescribed oral bisphosphonates, but there are concerns about their adverse effects. Osteonecrosis of the jaw is a recognised uncommon but important side effect of intravenous bisphosphonates, but epidemiological evidence on risk of osteonecrosis of the jaw associated with oral bisphosphonate use is less conclusive. The incidence of hospital admission with osteonecrosis of the jaw was examined among 521,695 Million Women Study participants, aged 64.7 years at baseline. Cox proportional hazards regression was used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs) associated with use of oral bisphosphonates in postmenopausal women followed-up by record-linkage to National Health Service hospital admission databases. During mean follow-up of 8.2 years per woman, 100 women were admitted to hospital with first recorded osteonecrosis of the jaw, at mean age 72.4 years. Almost a third (29/100) of the cases had ever-used oral bisphosphonates. Ever-users had a six-fold increased risk of hospital admission for osteonecrosis of the jaw, when compared with never-users (adjusted RR = 6.09, 95% CI 3.83-9.66; p < 0.0001). The relative risk for osteonecrosis of the jaw in never-users of oral bisphosphonates was increased in women with prior cancer (RR = 3.40, 2.22-5.22, p < 0.0001). The estimated absolute risk of hospital admission for osteonecrosis of the jaw over a 5-year period from age 70 to 74 in women without prior cancer was 0.09 per 1000 in never-users and 0.69 per 1000 in ever-users of oral bisphosphonates. In this UK population of postmenopausal women, use of oral bisphosphonates was associated with a 6-fold increased risk of hospital admission with osteonecrosis of the jaw, accounting for around one-third of cases, with an excess risk of about 0.6/1000 users over 5 years.

Foods, macronutrients and breast cancer risk in postmenopausal women: a large UK cohort

BACKGROUND

The role of diet in breast cancer aetiology is unclear; recent studies have suggested associations may differ by estrogen receptor status.

METHODS

Baseline diet was assessed in 2000-04 using a validated questionnaire in 691 571 postmenopausal UK women without previous cancer, who had not changed their diet recently. They were followed by record linkage to national cancer and death databases. Cox regression yielded adjusted relative risks for breast cancer for 10 food items and eight macronutrients, subdivided mostly into five categories of baseline intake. Trends in risk across the baseline categories were calculated, assigning re-measured intakes to allow for measurement error and changes in intake over time; P-values allowed for multiple testing.

RESULTS

Women aged 59.9 (standard deviation (SD 4.9)) years at baseline were followed for 12 (SD 3) years; 29 005 were diagnosed with invasive breast cancer. Alcohol intake had the strongest association with breast cancer incidence: relative risk (RR) 1.08 [99% confidence interval (CI) 1.05-1.11] per 10 g/day higher intake, P = 5.8 × 10-14. There were inverse associations with fruit: RR 0.94 (99% CI 0.92-0.97) per 100 g/day higher intake, P = 1.1 × 10-6, and dietary fibre: RR 0.91 (99% CI 0.87-0.96) per 5 g/day increase, P = 1.1 × 10-4. Fruit and fibre intakes were correlated (ρ = 0.62) and were greater among women who were not overweight, so residual confounding cannot be excluded. There was no heterogeneity for any association by estrogen receptor status.

CONCLUSIONS

By far the strongest association was between alcohol intake and an increased risk of breast cancer. Of the other 17 intakes examined, higher intakes of fruit and fibre were associated with lower risks of breast cancer, but it is unclear whether or not these associations are causal.

Association of ten gastrointestinal and other medical conditions with positivity to faecal occult blood testing in routine screening: a large prospective study of women in England

BACKGROUND

In 2006, the Bowel Cancer Screening Programme (BCSP) in England began offering biennial faecal occult blood testing (FOBt) at ages 60-69 years. Although FOBt is aimed at detecting colorectal neoplasms, other conditions can affect the result. In a large UK prospective study, we examined associations, both before and after screening, between FOBt positivity and 10 conditions that are often associated with gastrointestinal bleeding.

METHODS

By electronically linking BCSP and Million Women Study records, we identified 604 495 women without previous colorectal cancer who participated in their first routine FOBt screening between 2006 and 2012. Regression models, using linked national hospital admission records, yielded adjusted relative risks (RRs) in FOBt-positive versus FOBt-negative women for colorectal cancer, adenoma, diverticular disease, inflammatory bowel disease, haemorrhoids, upper gastrointestinal cancer, oesophagitis, peptic ulcer, anaemia and other haematological disorders.

RESULTS

RRs in FOBt-positive versus FOBt-negative women were 201.3 (95% CI 173.8-233.2) for colorectal cancer and 197.9 (95% CI 180.6-216.8) for adenoma within 12 months after screening and 3.49 (95% CI 2.31-5.26) and 4.88 (95% CI 3.80-6.26), respectively, 12-24 months after screening; P < 0.001 for all RRs. In the 12 months after screening, the RR for inflammatory bowel disease was 26.3 (95% CI 19.9-34.7), and ranged between 2 and 5 for the upper gastrointestinal or haematological disorders. The RRs of being diagnosed with any of the eight conditions other than colorectal neoplasms before screening, and in the 12-24 months after screening, were 1.81 (95% CI 1.81-2.01) and 1.92 (95% CI 1.66-2.13), respectively.

CONCLUSIONS

Whereas FOBt positivity is associated with a substantially increased risk of colorectal neoplasms after screening, eight other gastrointestinal and haematological conditions are also associated with FOBt positivity, both before and after screening.

Alcohol drinking patterns and liver cirrhosis risk: analysis of the prospective UK Million Women Study

BACKGROUND

Alcohol is a known cause of cirrhosis, but it is unclear if the associated risk varies by whether alcohol is drunk with meals, or by the frequency or type of alcohol consumed. Here we aim to investigate the associations between alcohol consumption with meals, daily frequency of consumption, and liver cirrhosis.

METHODS

The Million Women Study is a prospective study that includes one in every four UK women born between 1935 and 1950, recruited between 1996 and 2001. In 2001 (IQR 2000-03), the participants reported their alcohol intake, whether consumption was usually with meals, and number of days per week it was consumed. Cox regression analysis yielded adjusted relative risks (RRs) for incident cirrhosis, identified by follow-up through electronic linkage to routinely collected national hospital admission, and death databases.

FINDINGS

During a mean of 15 years (SD 3) of follow-up of 401 806 women with a mean age of 60 years (SD 5), without previous cirrhosis or hepatitis, and who reported drinking at least one alcoholic drink per week, 1560 had a hospital admission with cirrhosis (n=1518) or died from the disease (n=42). Cirrhosis incidence increased with amount of alcohol consumed (≥15 drinks [mean 220 g of alcohol] vs one to two drinks [mean 30 g of alcohol] per week; RR 3·43, 95% CI 2·87-4·10; p<0·0001). About half of the participants (203 564 of 401 806) reported usually drinking with meals and, after adjusting for amount consumed, cirrhosis incidence was lower for usually drinking with meals than not (RR 0·69, 0·62-0·77; p<0·0001; wine-only drinkers RR 0·69, 0·56-0·85; all other drinkers RR 0·72, 0·63-0·82). Among 175 618 women who consumed seven or more drinks per week, cirrhosis incidence was greater for daily consumption than non-daily consumption (adjusted RR 1·61, 1·40-1·85; p<0·0001). Daily consumption, together with not drinking with meals, was associated with more than a doubling of cirrhosis incidence (adjusted RR 2·47, 1·96-3·11; p<0·0001).

INTERPRETATION

In middle-aged women, cirrhosis incidence increases with total alcohol intake, even at moderate levels of consumption. For a given weekly intake of alcohol, this excess incidence of cirrhosis is higher if consumption is usually without meals, or with daily drinking.

FUNDING

UK Medical Research Council and Cancer Research UK.

Heterogeneous relationships of squamous and basal cell carcinomas of the skin with smoking: the UK Million Women Study and meta-analysis of prospective studies

INTRODUCTION

Published findings on the associations between smoking and the incidence of cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are inconsistent. We aimed to generate prospective evidence on these relationships overall and by anatomical site.

METHODS

We followed 1,223,626 women without prior cancer by electronic linkage to national cancer registration data. Questionnaire information about smoking and other factors was recorded at recruitment (1996-2001) and every 3-5 years subsequently. Cox regression yielded adjusted relative risks (RRs) comparing smokers versus never-smokers.

RESULTS

After 14 (SD4) years follow-up per woman, 6699 had a first registered cutaneous SCC and 48,666 a first BCC. In current versus never-smokers, SCC incidence was increased (RR = 1.22, 95% CI 1.15-1.31) but BCC incidence was decreased (RR = 0.80, 0.78-0.82). RRs varied substantially by anatomical site; for the limbs, current smoking was associated with an increased incidence of SCC (1.55, 1.41-1.71) and a decreased incidence of BCC (0.72, 0.66-0.79), but for facial lesions there was little association of current smoking with either SCC (0.93, 0.82-1.06) or BCC (0.92, 0.88-0.96). Findings in meta-analyses of results from this and seven other prospective studies were largely dominated by the findings in this study.

CONCLUSIONS

Smoking-associated risks for cutaneous SCC and BCC are in the opposite direction to each other and appear to vary by anatomical site.

Differences in risk factors for 3 types of stroke: UK prospective study and meta-analyses

OBJECTIVE

To compare associations of behavioral and related factors for incident subarachnoid hemorrhage and intracerebral hemorrhage and ischemic stroke.

METHODS

A total of 712,433 Million Women Study participants without prior stroke, heart disease, or cancer reported behavioral and related factors at baseline (1999-2007) and were followed up by record linkage to national hospital admission and death databases. Cox regression yielded adjusted relative risks (RRs) by type of stroke. Heterogeneity was assessed with χ2 tests. When appropriate, meta-analyses were done of published prospective studies.

RESULTS

After 12.9 (SD 2.6) years of follow-up, 8,128 women had an incident ischemic stroke, 2,032 had intracerebral hemorrhage, and 1,536 had subarachnoid hemorrhage. In women with diabetes mellitus, the risk of ischemic stroke was substantially increased (RR 2.01, 95% confidence interval [CI] 1.84-2.20), risk of intracerebral hemorrhage was increased slightly (RR 1.31, 95% CI 1.04-1.65), but risk of subarachnoid hemorrhage was reduced (RR 0.43, 95% CI 0.26-0.69) (heterogeneity by stroke type, p < 0.0001). Stroke incidence was greater in women who rated their health as poor/fair compared to those who rated their health as excellent/good (RR 1.36, 95% CI 1.30-1.42). Among 565,850 women who rated their heath as excellent/good, current smokers were at an increased risk of all 3 stroke types, (although greater for subarachnoid hemorrhage [≥15 cigarettes/d vs never smoker, RR 4.75, 95% CI 4.12-5.47] than for intracerebral hemorrhage [RR 2.30, 95% CI 1.94-2.72] or ischemic stroke [RR 2.50, 95% CI 2.29-2.72]; heterogeneity p < 0.0001). Obesity was associated with an increased risk of ischemic stroke and a decreased risk of hemorrhagic stroke (heterogeneity p < 0.0001). Meta-analyses confirmed the associations and the heterogeneity across the 3 types of stroke.

CONCLUSION

Classic risk factors for stroke have considerably different effects on the 3 main pathologic types of stroke.

Histological subtypes of ovarian cancer associated with parity and breastfeeding in the prospective Million Women Study

Ovarian cancer risk is known to be reduced amongst women who have had children, but reported associations with breastfeeding are varied. Few studies have had sufficient power to explore reliably these associations by tumour histotype. In a prospective study of 1.1 million UK women, 8719 developed ovarian cancer during follow-up. Cox regression yielded adjusted relative risks (RRs) overall and by tumour histotype amongst women with different childbearing patterns. Nulliparous women had a 24% greater ovarian cancer risk than women with one child, with significant heterogeneity by histotype (p = 0.01). There was no significant increase in serous tumours, a modest increase in mucinous tumours, but a substantial increase in endometrioid (RR = 1.49, 95% CI: 1.18-1.89) and clear-cell tumours (RR = 1.68, 1.29-2.20). Among parous women, each additional birth was associated with an overall 6% reduction in ovarian cancer risk; this association also varied by histotype (p = 0.0006), with the largest reduction in risk for clear-cell tumours (RR per birth = 0.75, 0.65-0.85, p < 0.001) and weak, if any, effect for endometrioid, high-grade serous, or mucinous tumours. We found little association with age at first or last birth. There was about a 10% risk reduction per 12-months breastfeeding (RR = 0.89, 0.84-0.94, p < 0.001), with no significant heterogeneity by histotype, but statistical power was limited. In this large prospective study, ovarian cancer risk associated with parity varied substantially by tumour histotype. Nulliparity was associated with a substantially greater overall risk than expected from the effect of a single birth, especially for clear cell and endometrioid tumours, perhaps suggesting that infertility is associated with these histotypes.

Factors associated with participation in colorectal cancer screening in Australia: Results from the 45 and Up Study cohort

The Australian Government's National Bowel Cancer Screening Program (NBCSP) was introduced in 2006 to provide free home-based immunochemical faecal occult blood test (iFOBT) to eligible Australians turning 55 and 65years in that year. With the gradual inclusion of additional age cohorts, the rollout of the NBCSP is being implemented in the context of a degree of opportunistic or de facto screening. This study investigated factors associated with self-reported ever-uptake of the NBCSP and of any CRC screening using follow-up questionnaire data from 105,897 Australians aged ≥45years enrolled in the 45 and Up Study in New South Wales, Australia. Of the 91,968 study participants with information on CRC screening behaviour, 70,444 (76.6%) reported ever-uptake of any CRC screening. 63,777 study participants were eligible for a NBCSP invitation, of these 33,148 (52.0%) reported ever-uptake of screening through the NBCSP. Current smoking (RR=0.86, 0.83-0.90), non-participation in breast cancer screening (female) or PSA testing (male) (RR=0.84, 0.81-0.86), poor self-reported health (RR=0.89, 0.86-0.91), lower levels of education (RR=0.91, 0.90-0.93), and not speaking English at home (RR=0.88, 0.85-0.91) were associated with reduced ever-uptake of screening within the NBCSP and of any CRC screening. Individuals with a family history of CRC were less likely to screen through the NBCSP (RR=0.71, 0.69-0.73), but more likely to participate in any CRC screening (RR=1.18, 1.17-1.19). Smokers, disadvantaged groups and those with non-English speaking backgrounds are less likely to have ever-participated in organised screening through the NBCSP or in any form of CRC screening, supporting efforts to improve participation in these groups.

Disability and participation in breast and bowel cancer screening in England: a large prospective study

BACKGROUND

There is limited information about participation in organised population-wide screening programmes by people with disabilities.

METHODS

Data from the National Health Service routine screening programmes in England were linked to information on disability reported by the Million Women Study cohort participants.

RESULTS

Of the 473 185 women offered routine breast or bowel cancer screening, 23% reported some disability. Women with disabilities were less likely than other women to participate in breast cancer screening (RR=0.64, 95% CI: 0.62-0.65) and in bowel cancer screening (RR=0.75, 0.73-0.76). Difficulties with self-care or vision were associated with the greatest reduction in screening participation.

CONCLUSION

Participation in routine cancer screening programmes in England is reduced in people with disabilities and participation varies by type of disability.

Antidepressants, Depression, and Venous Thromboembolism Risk: Large Prospective Study of UK Women

BACKGROUND

Some investigators have reported an excess risk of venous thromboembolism (VTE) associated with depression and with use of antidepressant drugs. We explored these associations in a large prospective study of UK women.

METHODS AND RESULTS

The Million Women Study recruited 1.3 million women through the National Health Service Breast Screening Programme in England and Scotland. Three years after recruitment, women were sent a second questionnaire that enquired about depression and regular use of medications in the previous 4 weeks. The present analysis included those who responded and did not have prior VTE, cancer, or recent surgery. Follow-up for VTE was through linkage to routinely collected National Health Service statistics. Cox regression analyses yielded adjusted hazard ratios and 95% CIs. A total of 734 092 women (mean age 59.9 years) were included in the analysis; 6.9% reported use of antidepressants, 2.7% reported use of other psychotropic drugs, and 1.8% reported being treated for depression or anxiety but not use of psychotropic drugs. During follow-up for an average of 7.3 years, 3922 women were hospitalized for and/or died from VTE. Women who reported antidepressant use had a significantly higher risk of VTE than women who reported neither depression nor use of psychotropic drugs (hazard ratio, 1.39; 95% CI, 1.23-1.56). VTE risk was not significantly increased in women who reported being treated for depression or anxiety but no use of antidepressants or other psychotropic drugs (hazard ratio, 1.19; 95% CI, 0.95-1.49).

CONCLUSIONS

Use of antidepressants is common in UK women and is associated with an increased risk of VTE.

Hospital costs in relation to body-mass index in 1·1 million women in England: a prospective cohort study

BACKGROUND

Excess weight is associated with poor health and increased health-care costs. However, a detailed understanding of the effects of excess weight on total hospital costs and costs for different health conditions is needed.

METHODS

Women in England aged 50-64 years were recruited into the prospective Million Women Study cohort in 1996-2001 through 60 NHS breast cancer screening centres. Participants were followed up and annual hospital costs and admission rates were estimated for April 1, 2006, to March 31, 2011, in relation to body-mass index (BMI) at recruitment, overall and for categories of health conditions defined by the International Classification of Diseases 10th revision chapter of the primary diagnosis at admission. Associations of BMI with hospital costs were projected to the 2013 population of women aged 55-79 years in England.

FINDINGS

1 093 866 women who provided information on height and weight, had a BMI of at least 18·5 kg/m2, and had no previous cancer at recruitment, were followed up for an average of 4·9 years from April 1, 2006 (12·3 years from recruitment), during which time 1·84 million hospital admissions were recorded. Annual hospital costs were lowest for women with a BMI of 20·0 kg/m2 to less than 22·5 kg/m2 (£567 per woman per year, 99% CI 556-577). Every 2 kg/m2 increase in BMI above 20 kg/m2 was associated with a 7·4% (7·1-7·6) increase in annual hospital costs. Excess weight was associated with increased costs for all diagnostic categories, except respiratory conditions and fractures. £662 million (14·6%) of the estimated £4·5 billion of total annual hospital costs among all women aged 55-79 years in England was attributed to excess weight (BMI ≥25 kg/m2), of which £517 million (78%) arose from hospital admissions with procedures. £258 million (39%) of the costs attributed to excess weight were due to musculoskeletal admissions, mainly for knee replacement surgeries.

INTERPRETATION

Excess body weight is associated with increased hospital costs for middle-aged and older women in England across a broad range of conditions, especially knee replacement surgery and diabetes. These results provide reliable up-to-date estimates of the health-care costs of excess weight and emphasise the need for investment to tackle this public health issue.

FUNDING

Cancer Research UK; Medical Research Council; National Institute for Health Research.

Heterogeneity of colorectal cancer risk by tumour characteristics: Large prospective study of UK women

Associations between behavioural and other personal factors and colorectal cancer risk have been reported to vary by tumour characteristics, but evidence is inconsistent. In a large UK-based prospective study we examined associations of 14 postulated risk factors with colorectal cancer risk overall, and across three anatomical sites and four morphological subtypes. Among 1.3 million women, 18,518 incident colorectal cancers were identified during 13.8 (SD 3.4) years follow-up via record linkage to national cancer registry data. Cox regression yielded adjusted relative risks. Statistical significance was assessed using correction for multiple testing. Overall, colorectal cancer risk was significantly associated with height, body mass index (BMI), smoking, alcohol intake, physical activity, parity and menopausal hormone therapy use. For smoking there was substantial heterogeneity across morphological types; relative risks around two or greater were seen in current smokers both for signet ring cell and for neuroendocrine tumours. Obese women were also at higher risk for signet ring cell tumours. For adenocarcinomas, the large majority of colorectal cancers in the cohort, all risk factor associations were weak. There was little or no heterogeneity in risk between tumours of the right colon, left colon and rectum for any of the 14 factors examined. These epidemiological findings complement an emerging picture from molecular studies of possible different developmental pathways for different tumour types.

Cancer risk among 21st century blood transfusion recipients

Background

Some carcinogenic viruses are known to be transmissible by blood transfusion. Intensive viral screening of transfused blood now exists in most countries. In the UK, high-sensitivity nucleic acid amplification tests for hepatitis C virus were introduced in 1999 and it was thought that this would reduce, and possibly eliminate, transfusion-related liver cancer. We aimed to investigate cancer risk in recipients of blood transfusion in 2000 or after.

Methods

A total of 1.3 million UK women recruited in 1998 on average were followed for hospital records of blood transfusion and for cancer registrations. After excluding women with cancer or precancerous conditions before or at the time of transfusion, Cox regression yielded adjusted relative risks of 11 site-specific cancers for women with compared to without prior blood transfusion.

Results

During follow up, 11 274 (0.9%) women had a first recorded transfusion in 2000 or after, and 1648 (14.6%) of them were subsequently diagnosed with cancer, a mean 6.8 years after the transfusion. In the first 5 years after transfusion there were significant excesses for most site-specific cancers examined, presumably because some had preclinical cancer. However, 5 or more years (mean 8 years) after blood transfusion, there were significant excess risks only for liver cancer (adjusted relative risk = 2.63, 95%CI 1.45-4.78) and for non-Hodgkin lymphoma (adjusted relative risk = 1.74, 1.21-2.51). When analyses were restricted to those undergoing hip or knee replacement surgery, the commonest procedure associated with transfusion, these relative risks were not materially altered.

Conclusions

In a large cohort of UK women, transfusions in the 21st century were associated with long-term increased risks of liver cancer and non-Hodgkin lymphoma. Some of these malignancies may have been caused by carcinogenic agents that are not currently screened for in transfused blood.