Risk of Fracture After Bilateral Oophorectomy

Fragility fractures, resulting from low-energy trauma, occur in approximately 1 in 10 Danish women aged 50 years or older. Bilateral oophorectomy (surgical removal of both ovaries) may increase the risk of fragility fractures due to loss of ovarian sex steroids, particularly estrogen. We investigated the association between bilateral oophorectomy and risk of fragility fracture and whether this was conditional on age at time of bilateral oophorectomy, hormone therapy (HT) use, hysterectomy, physical activity level, body mass index (BMI), or smoking. We performed a cohort study of 25,853 female nurses (≥45 years) participating in the Danish Nurse Cohort. Nurses were followed from age 50 years or entry into the cohort, whichever came last, until date of first fragility fracture, death, emigration, or end of follow-up on December 31, 2018, whichever came first. Cox regression models with age as the underlying time scale were used to estimate the association between time-varying bilateral oophorectomy (all ages, <51/≥51 years) and incident fragility fracture (any and site-specific [forearm, hip, spine, and other]). Exposure and outcome were ascertained from nationwide patient registries. During 491,626 person-years of follow-up, 6600 nurses (25.5%) with incident fragility fractures were identified, and 1938 (7.5%) nurses had a bilateral oophorectomy. The frequency of fragility fractures was 24.1% in nurses who were <51 years at time of bilateral oophorectomy and 18.1% in nurses who were ≥51 years. No statistically significant associations were observed between bilateral oophorectomy at any age and fragility fractures at any site. Neither HT use, hysterectomy, physical activity level, BMI, nor smoking altered the results. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Symptom patterns and health service use of women in early adulthood: a latent class analysis from the Australian Longitudinal Study on Women's Health

BACKGROUND

Symptoms can be strong drivers for initiating interaction with the health system, especially when they are frequent, severe or impact on daily activities. Research on symptoms often use counts of symptoms as a proxy for symptom burden, however simple counts don't provide information on whether groups of symptoms are likely to occur together or whether such groups are associated with different types and levels of healthcare use. Women have a higher symptom burden than men; however studies of symptom patterns in young women are lacking. We aimed to characterise subgroups of women in early adulthood who experienced different symptom patterns and to compare women's use of different types of health care across the different symptom subgroups.

METHODS

Survey and linked administrative data from 7 797 women aged 22-27 years in 2017 from the 1989-95 cohort of the Australian Longitudinal Study on Women's Health were analysed. A latent class analysis was conducted to identify subgroups of women based on the frequency of 16 symptom variables. To estimate the associations between the latent classes and health service use, we used the "Bolck, Croon and Hagenaars" (BCH) approach that takes account of classification error in the assignment of women to latent classes.

RESULTS

Four latent classes were identified, characterised by 1) low prevalence of most symptoms (36.6%), 2) high prevalence of menstrual symptoms but low prevalence of mood symptoms (21.9%), 3) high prevalence of mood symptoms but low prevalence of menstrual symptoms, (26.2%), and high prevalence of many symptoms (15.3%). Compared to the other three classes, women in the high prevalence of many symptoms class were more likely to visit general practitioners and specialists, use more medications, and more likely to have had a hospital admission.

CONCLUSIONS

Women in young adulthood experience substantially different symptom burdens. A sizeable proportion of women experience many co-occurring symptoms across both physical and psychological domains and this high symptom burden is associated with a high level of health service use. Further follow-up of the women in our study as they enter their late 20 s and early 30 s will allow us to examine the stability of the classes of symptoms and their associations with general health and health service use. Similar studies in other populations are needed to assess the generalisability of the findings.

Menopause, hysterectomy, menopausal hormone therapy and cause-specific mortality: cohort study of UK Biobank participants

STUDY QUESTION

What is the association between menopausal hormone therapy (MHT) and cause-specific mortality?

SUMMARY ANSWER

Self-reported MHT use following early natural menopause, surgical menopause or premenopausal hysterectomy is associated with a lower risk of breast cancer mortality and is not consistently associated with the risk of mortality from cardiovascular disease or other causes.

WHAT IS KNOWN ALREADY

Evidence from the Women's Health Initiative randomized controlled trials showed that the use of estrogen alone is not associated with the risk of cardiovascular mortality and is associated with a lower risk of breast cancer mortality, but evidence from the Million Women Study showed that use of estrogen alone is associated with a higher risk of breast cancer mortality.

STUDY DESIGN, SIZE, DURATION

Cohort study (the UK Biobank), 178 379 women, recruited in 2006-2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Postmenopausal women who had reported age at menopause (natural or surgical) or hysterectomy, and information on MHT and cause-specific mortality. Age at natural menopause, age at surgical menopause, age at hysterectomy and MHT were exposures of interest. Natural menopause was defined as spontaneous cessation of menstruation for 12 months with no previous hysterectomy or oophorectomy. Surgical menopause was defined as the removal of both ovaries prior to natural menopause. Hysterectomy was defined as removal of the uterus before natural menopause without bilateral oophorectomy. The study outcome was cause-specific mortality.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 178 379 women included, 136 790 had natural menopause, 17 569 had surgical menopause and 24 020 had hysterectomy alone. Compared with women with natural menopause at the age of 50-52 years, women with natural menopause before 40 years (hazard ratio (HR): 2.38, 95% CI: 1.64, 3.45) or hysterectomy before 40 years (HR: 1.60, 95% CI: 1.23, 2.07) had a higher risk of cardiovascular mortality but not cancer mortality. MHT use was associated with a lower risk of breast cancer mortality following surgical menopause before 45 years (HR: 0.17, 95% CI: 0.08, 0.36), at 45-49 years (HR: 0.15, 95% CI: 0.07, 0.35) or at ≥50 years (HR: 0.28, 95% CI: 0.13, 0.63), and the association between MHT use and the risk of breast cancer mortality did not differ by MHT use duration (<6 or 6-20 years). MHT use was also associated with a lower risk of breast cancer mortality following natural menopause before 45 years (HR: 0.59, 95% CI: 0.36, 0.95) or hysterectomy before 45 years (HR: 0.49, 95% CI: 0.32, 0.74).

LIMITATIONS, REASONS FOR CAUTION

Self-reported data on age at natural menopause, age at surgical menopause, age at hysterectomy and MHT.

WIDER IMPLICATIONS OF THE FINDINGS

The current international guidelines recommend women with early menopause to use MHT until the average age at menopause. Our findings support this recommendation.

STUDY FUNDING/COMPETING INTEREST(S)

This project is funded by the Australian National Health and Medical Research Council (NHMRC) (grant numbers APP1027196 and APP1153420). G.D.M. is supported by NHMRC Principal Research Fellowship (APP1121844), and M.H. is supported by an NHMRC Investigator Grant (APP1193838). There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Oophorectomy and rate of dementia: a prospective cohort study

OBJECTIVE

Globally, dementia disproportionally affects women, which is not fully explained by higher female longevity. Oophorectomy at any age leads to the permanent loss of ovarian sex steroids, potentially increasing the risk of dementia. We aimed to investigate the association between oophorectomy and dementia and whether this was conditional on age at oophorectomy, hysterectomy or use of hormone therapy (HT).

METHODS

A prospective study of 24,851 female nurses from the Danish Nurse Cohort. Nurses were followed from age 60 years or entry into the cohort, whichever came last, until date of dementia, death, emigration or end of follow-up (December 31, 2018), whichever came first. Poisson regression models with log-transformed person-years as offset were used to estimate the associations.

RESULTS

During 334,420 person-years of follow-up, 1,238 (5.0%) nurses developed dementia and 1,969 (7.9%)/ 1,016 (4.1%) contributed person-time after bilateral-/unilateral oophorectomy. In adjusted analyses, an 18% higher rate of dementia was observed following bilateral oophorectomy (aRR 1.18: 95% CI, 0.89-1.56) and 13% lower rate (aRR 0.87: 95% CI, 0.59-1.23) following unilateral oophorectomy compared to nurses who retained their ovaries. Similar effects were detected after stratification according to age at oophorectomy. No statistically significant modifying effects of hysterectomy or HT were detected (Pinteraction≥0.60).

CONCLUSIONS

Bilateral, but not unilateral, oophorectomy was associated with an increased rate of incident dementia. We were unable to establish whether this association was conditional on hysterectomy or HT use. Although an increase in dementia after bilateral oophorectomy is biologically plausible, limited statistical power hampers the precision of the estimates.

Priorities for Safer In-Person School for Children With Medical Complexity During COVID-19

OBJECTIVES

To establish statewide consensus priorities for safer in-person school for children with medical complexity (CMC) during the coronavirus disease 2019 (COVID-19) pandemic using a rapid, replicable, and transparent priority-setting method.

METHODS

We adapted the Child Health and Nutrition Research Initiative Method, which allows for crowdsourcing ideas from diverse stakeholders and engages technical experts in prioritizing these ideas using predefined scoring criteria. Crowdsourcing surveys solicited ideas from CMC families, school staff, clinicians and administrators through statewide distribution groups/listservs using the prompt: "It is safe for children with complex health issues and those around them (families, teachers, classmates, etc.) to go to school in-person during the COVID-19 pandemic if/when…" Ideas were aggregated and synthesized into a unique list of candidate priorities. Thirty-four experts then scored each candidate priority against 5 criteria (equity, impact on COVID-19, practicality, sustainability, and cost) using a 5-point Likert scale. Scores were weighted and predefined thresholds applied to identify consensus priorities.

RESULTS

From May to June 2021, 460 stakeholders contributed 1166 ideas resulting in 87 candidate priorities. After applying weighted expert scores, 10 consensus CMC-specific priorities exceeded predetermined thresholds. These priorities centered on integrating COVID-19 safety and respiratory action planning into individualized education plans, educating school communities about CMC's unique COVID-19 risks, using medical equipment safely, maintaining curricular flexibility, ensuring masking and vaccination, assigning seats during transportation, and availability of testing and medical staff at school.

CONCLUSIONS

Priorities for CMC, identified by statewide stakeholders, complement and extend existing recommendations. These priorities can guide implementation efforts to support safer in-person education for CMC.

The long-term association between bilateral oophorectomy and depression: a prospective cohort study

OBJECTIVE

Depression is a leading cause of disability globally and affects more women than men. Ovarian sex steroids are thought to modify depression risk in women and interventions such as bilateral oophorectomy that permanently change the sex steroid milieu may increase the risk of depression. This study aimed to investigate the associations between unilateral and bilateral oophorectomy and depression over a 25-year period (1993-2018) and whether this varied by age at oophorectomy or use of menopausal hormone therapy.

METHODS

Twenty-five thousand one hundred eighty-eight nurses aged ≥45 years from the Danish Nurse Cohort were included. Nurses with depression prior to baseline were excluded. Poisson regression models, with log-transformed person-years as offset, were used to assess the associations between oophorectomy and incident depression. Nurses who retained their ovaries were the reference group.

RESULTS

Compared with nurses with retained ovaries, bilateral oophorectomy was associated with a slightly higher rate of depression (rate ratio [RR], 1.08; 95% confidence interval [CI], 0.95-1.23), but without statistical significance. However, when stratified by age at oophorectomy, compared with nurses with retained ovaries, bilateral oophorectomy at age ≥51 years was associated with higher rates of depression (RR 1.16; 95% CI, 1.00-1.34), but not bilateral oophorectomy at age <51 years (RR 0.86; 95% CI, 0.69-1.07); P value for difference in estimates = 0.02. No association between unilateral oophorectomy and depression was observed.

CONCLUSIONS

In this cohort of Danish female nurses, bilateral oophorectomy at age ≥51 years, but not at younger ages, was associated with a slightly higher rate of depression compared with those who retained their ovaries.

Cardiovascular mortality after bilateral oophorectomy: a prospective cohort study

OBJECTIVES

Bilateral oophorectomy permanently reduces endogenous estrogen exposure and may increase cardiovascular mortality in women. This study aimed to investigate the association between bilateral oophorectomy and cardiovascular mortality and whether this association was conditional on hysterectomy or on the use of hormone therapy at the time of study entry.

METHODS

A prospective cohort study of 25,338 female nurses aged ≥ 45 years within the Danish Nurse Cohort. Nurses were enrolled in 1993 or 1999 and followed until death, emigration, or end of follow-up on December 31, 2018, whichever came first. Exposure was bilateral oophorectomy. Outcome was cardiovascular mortality. Associations were estimated using Poisson regression models with log person-years as the offset.

RESULTS

A total of 2,040 (8.1%) participants underwent bilateral oophorectomy. During a mean follow-up of 21.2 (SD: 5.6) years, 772 (3.0%) nurses died from cardiovascular disease. In adjusted analyses, a 31% higher rate of cardiovascular mortality was observed after bilateral oophorectomy (aMRR 1.31; 95% CI, 0.88-1.96) compared with women who retained their ovaries. No evidence of effect modification by use of hormone therapy at baseline or by hysterectomy on the association between bilateral oophorectomy and cardiovascular mortality was observed.

CONCLUSION

Bilateral oophorectomy may be associated with cardiovascular mortality in women, but the estimate was not statistically significant. Additionally, we were unable to make firm conclusions regarding the possible modifying role of hormone therapy and hysterectomy on this potential association. Additional studies are needed to replicate this work.

Asthma severity and impact on perinatal outcomes: an updated systematic review and meta-analysis

BACKGROUND

Large-scale studies exploring the associations of asthma severity, exacerbations and medication use with adverse perinatal outcomes have been published in recent years.

OBJECTIVES

To update evidence on the associations of asthma severity, exacerbations and medication use with the adverse perinatal outcomes of preterm delivery (PD), low birthweight (LBW) and small-for-gestational-age (SGA).

SEARCH STRATEGY

PubMed, Embase, Wanfang, and China National Knowledge Infrastructure (CNKI) from inception to 1 January 2021.

SELECTION CRITERIA

Cohort studies comparing the likelihood of adverse perinatal outcomes in groups of asthmatic women stratified by asthma severity, asthma exacerbations or medication use, or comparing the likelihood of adverse perinatal outcomes between non-asthmatic women and asthmatics of various levels of severity and exacerbation.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Random-effects models were used to meta-analyse the results.

MAIN RESULTS

Twenty studies met the inclusion criteria. The odds of delivering SGA babies increased with maternal asthma severity. Pregnant women with an asthma exacerbation had higher odds of delivering LBW babies and SGA babies, compared with pregnant women with asthma but without an exacerbation (pooled adjusted odds ratio [OR] 1.15, 95% CI 1.02-1.29 for LBW; number of studies with adjusted OR 3; I²  = 0%) (pooled adjusted OR 1.13, 95% CI 1.04-1.23 for SGA; number of studies with adjusted OR 4; I²  = 0%) and compared to pregnant women without asthma. Oral corticosteroids use during pregnancy was associated with increased odds of LBW, but not PD.

CONCLUSIONS

The available data suggest that maternal asthma severity and exacerbations are associated with increased odds of LBW and SGA babies.

TWEETABLE ABSTRACT

A systematic review and meta-analysis found that maternal asthma severity and exacerbations are associated with increased odds of delivering low birthweight and small-for-gestational-age babies.

Hysterectomy and Risk of Breast, Colorectal, Thyroid, and Kidney Cancer - an Australian Data Linkage Study

BACKGROUND

This study aimed to investigate the associations between hysterectomy for benign indications and risk of breast, colorectal, kidney, and thyroid cancer, and to explore whether these associations are modified by removal of ovaries at the time of surgery or by age at surgery.

METHODS

We conducted a retrospective cohort study of the female population of Western Australia (n = 839,332) linking data from electoral, hospital, births, deaths, and cancer records. We used Cox regression to estimate HRs and 95% confidence intervals (CI) for the associations between hysterectomy and diagnosis of breast, colorectal, kidney, and thyroid cancers.

RESULTS

Compared with no surgery, hysterectomy without oophorectomy (hysterectomy) and hysterectomy with bilateral salpingo-oophorectomy (hysterectomy-BSO) were associated with higher risk of kidney cancer (HR, 1.32; 95% CI, 1.11-1.56 and HR, 1.29; 95% CI, 0.96-1.73, respectively). Hysterectomy, but not hysterectomy-BSO, was related to higher risk of thyroid cancer (HR, 1.38; 95% CI, 1.19-1.60). In contrast, hysterectomy (HR, 0.94; 95% CI, 0.90-0.98) and hysterectomy-BSO (HR, 0.92; 95% CI, 0.85-1.00) were associated with lower risk of breast cancer. We found no association between hysterectomy status and colorectal cancer.

CONCLUSIONS

The associations between hysterectomy and cancer varied by cancer type with increased risks for thyroid and kidney cancer, decreased risk for breast cancer, and no association for colorectal cancer.

IMPACT

As breast, colorectal, and gynecologic cancers comprise a sizeable proportion of all cancers in women, our results suggest that hysterectomy is unlikely to increase overall cancer risk; however, further research to understand the higher risk of thyroid and kidney cancer is warranted.

Hysterectomy with and without oophorectomy and all-cause and cause-specific mortality

BACKGROUND

Hysterectomy is one of the most commonly performed gynecologic surgeries, with an estimated 30% of women in Australia undergoing the procedure by age of 70 years. In the United States, about 45% of women undergo hysterectomy in their lifetime. Some studies have suggested that this procedure increases the risk of premature mortality. With many women making the decision to undergo hysterectomy for a benign indication each year, additional research is needed to clarify whether there are long-term health consequences of hysterectomy.

OBJECTIVE

This study aimed to examine the association between hysterectomy for benign indications, with or without removal of the ovaries, and cause-specific and all-cause mortality.

STUDY DESIGN

Our cohort of 666,588 women comprised the female population of Western Australia with linked hospital and health records from 1970 to 2015. Cox regression models were used to assess the association between hysterectomy and all-cause, cardiovascular disease, cancer, and other mortality by oophorectomy type (categorized as none, unilateral, and bilateral), with no hysterectomy or oophorectomy as the reference group. We repeated these analyses using hysterectomy without oophorectomy as the reference group. We also investigated whether associations varied by age at the time of surgery, although small sample size precluded this analysis in women who underwent hysterectomy with unilateral salpingo-oophorectomy. In our main analysis, women who underwent hysterectomy or oophorectomy as part of cancer treatment were retained in the analysis and considered unexposed to that surgery. For a sensitivity analysis, we censored procedures performed for cancer.

RESULTS

Compared with no surgery, hysterectomy without oophorectomy before 35 years was associated with an increase in all-cause mortality (hazard ratio, 1.29; 95% confidence interval, 1.19-1.40); for surgery after 35 years of age, there was an inverse association (35-44 years: hazard ratio, 0.93; 95% confidence interval, 0.89-0.97). Similarly, hysterectomy with bilateral salpingo-oophorectomy before 45 years of age was associated with increased all-cause mortality (35-44 years: hazard ratio, 1.15; 95% confidence interval, 1.04-1.27), but decreased mortality rates after 45 years of age. In our sensitivity analysis, censoring gynecologic surgeries for cancer resulted in many cancer-related deaths being excluded for women who did not have surgery for benign indications and thus increased the hazard ratios for the associations between both hysterectomy without oophorectomy and hysterectomy with bilateral salpingo-oophorectomy and risk of all-cause and cancer-specific mortality. The sensitivity analysis therefore potentially biased the results in favor of no surgery.

CONCLUSION

Among women having surgery for benign indications, hysterectomy without oophorectomy performed before 35 years of age and hysterectomy with bilateral salpingo-oophorectomy performed before 45 years of age were associated with an increase in all-cause mortality. These procedures are not associated with poorer long-term survival when performed at older ages.

The proportion of cancers attributable to social deprivation: A population-based analysis of Australian health data

BACKGROUND

Cancer is a major disease burden globally and people who are socioeconomically disadvantaged have a higher incidence of many types of cancer. We investigated the potential to reduce socioeconomic disparities in cancer incidence in Australia by lowering the prevalence of exposure to four modifiable causes: smoking, alcohol, overweight/obesity and physical inactivity.

METHODS

We used cancer incidence data from the Australian Cancer Database and risk factor prevalence data from the Australian National Health Survey to estimate the proportions of cancers attributable to the four factors, by area-level socioeconomic disadvantage. For the three risk factors where prevalence was lowest among the least disadvantaged (smoking, overweight/obesity, physical inactivity), we also estimated the potential impact of reducing prevalence in the most disadvantaged areas to that in the least disadvantaged areas.

RESULTS

The proportion of cancer attributable to the four factors in combination ranged from 22 % in the most disadvantaged areas to 14 % in the least disadvantaged areas. If the prevalence of tobacco smoking, overweight/obesity and physical inactivity in the more disadvantaged areas were the same as that in the least disadvantaged, an estimated 19,500 cancers (4 % of all cancers diagnosed) could have been prevented in Australia between 2009 and 2013.

CONCLUSIONS

Reducing the prevalence of key causal factors in areas of greater social disadvantage would prevent many cases of cancer. Strategies to achieve this in highly disadvantaged areas are needed.

The impact of reducing alcohol consumption in Australia: An estimate of the proportion of potentially avoidable cancers 2013-2037

The International Agency for Research on Cancer first concluded that alcohol causes cancer in humans in 1988. The World Cancer Research Fund has declared that alcohol causes cancer of the oral cavity, pharynx, larynx, oesophagus (squamous cell carcinoma), female breast, colon, rectum, stomach and liver. It recommended that alcohol be avoided altogether to prevent cancer. We aimed to quantify the impact of reducing alcohol consumption on future cancer incidence in Australia. We used PREVENT 3.01 simulation modelling software to estimate the proportion of cancers that could potentially be prevented over a 25-year period under two hypothetical intervention scenarios and two latency periods (20 and 30 years). Under a scenario where alcohol consumption abruptly ceases, we estimated up to 4% of alcohol-related cancers could be avoided over a 25-year period (~49,500 cancers, depending on assumed latency). If the maximum consumption of all Australian adults was ≤20 g/day (~two Australian standard drinks), up to 2% of alcohol-related cancers could be avoided (~29,600 cancers). The maximum proportions were higher for men (6% for no alcohol consumption; 5% for ≤20 g/day) than women (3%; 1%). The proportion avoidable was highest for oesophageal squamous cell carcinoma (17% no alcohol consumption; 9% ≤20 g/day), followed by cancers of the oral cavity (12%; 5%) and pharynx (11%; 5%). The cancer sites with the highest numbers of potentially avoidable cases were colon in men (11,500; 9,900) and breast in women (14,400; 4,100). Successful interventions to reduce alcohol intake could lead to significant reductions in cancer incidence.

The Association Between Hysterectomy and Ovarian Cancer Risk: A Population-Based Record-Linkage Study

BACKGROUND

Recent studies have called into question the long-held belief that hysterectomy without oophorectomy protects against ovarian cancer. This population-based longitudinal record-linkage study aimed to explore this relationship, overall and by age at hysterectomy, time period, surgery type, and indication for hysterectomy.

METHODS

We followed the female adult Western Australian population (837 942 women) across a 27-year period using linked electoral, hospital, births, deaths, and cancer records. Surgery dates were determined from hospital records, and ovarian cancer diagnoses (n = 1640) were ascertained from cancer registry records. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between hysterectomy and ovarian cancer incidence.

RESULTS

Hysterectomy without oophorectomy (n = 78 594) was not associated with risk of invasive ovarian cancer overall (HR = 0.98, 95% CI = 0.85 to 1.11) or with the most common serous subtype (HR = 1.05, 95% CI = 0.89 to 1.23). Estimates did not vary statistically significantly by age at procedure, time period, or surgical approach. However, among women with endometriosis (5.8%) or with fibroids (5.7%), hysterectomy was associated with substantially decreased ovarian cancer risk overall (HR = 0.17, 95% CI = 0.12 to 0.24, and HR = 0.27, 95% CI = 0.20 to 0.36, respectively) and across all subtypes.

CONCLUSIONS

Our results suggest that for most women, having a hysterectomy with ovarian conservation is not likely to substantially alter their risk of developing ovarian cancer. However, our results, if confirmed, suggest that ovarian cancer risk reduction could be considered as a possible benefit of hysterectomy when making decisions about surgical management of endometriosis or fibroids.

Hysterectomy status and all-cause mortality in a 21-year Australian population-based cohort study

BACKGROUND

Hysterectomy is a common surgical procedure, predominantly performed when women are between 30 and 50 years old. One in 3 women in Australia has had a hysterectomy by the time they are 60 years old, and 30% have both ovaries removed at the time of surgery. Given this high prevalence, it is important to understand the long-term effects of hysterectomy. In particular, women who have a hysterectomy/oophorectomy at younger ages are likely to be premenopausal or perimenopausal and may experience greater changes in hormone levels and a shortened reproductive lifespan than women who have a hysterectomy when they are older and postmenopausal. Use of menopausal hormone therapy after surgery may compensate for these hormonal changes. To inform clinical decisions about postsurgery management of women who have a hysterectomy prior to menopause (ie, average age at menopause 50 years), it is useful to compare women with a hysterectomy to women with no hysterectomy and to stratify the hysterectomy status by whether or not women have had a bilateral oophorectomy, or used menopausal hormone therapy.

OBJECTIVE

We sought to investigate whether women who had a hysterectomy with ovarian conservation or a hysterectomy and bilateral oophorectomy before the age of 50 years were at a higher risk of premature all-cause mortality compared to women who did not have this surgery before the age of 50 years. We also sought to explore whether use of menopausal hormone therapy modified these associations.

STUDY DESIGN

Women from the midcohort (born 1946 through 1951) of the Australian Longitudinal Study on Women's Health were included in our study sample (n = 13,541). Women who reported a hysterectomy (with and without both ovaries removed) before the age of 50 years were considered exposure at risk and compared with women who did not report these surgeries before age 50 years. To explore effect modification by use of menopausal hormone therapy we further stratified hysterectomy status by menopausal hormone therapy use. Risk of all-cause mortality was assessed using inverse-probability weighted Cox regression models.

RESULTS

During a median follow-up of 21.5 years, there were 901 (6.7%) deaths in our study sample. Overall, there was no difference in all-cause mortality between women who reported a hysterectomy with ovarian conservation (hazard ratio, 0.86; 95% confidence interval, 0.72-1.02) or women who reported a hysterectomy and bilateral oophorectomy (hazard ratio, 1.02; 95% confidence interval, 0.78-1.34) and women with no hysterectomy. When stratified by menopausal hormone therapy use, women with hysterectomy and ovarian conservation before the age of 50 years were not at higher risk of all-cause mortality compared to no hysterectomy, regardless of menopausal hormone therapy use status. In contrast, among nonusers of menopausal hormone therapy only, women who reported a hysterectomy-bilateral oophorectomy before the age of 50 years were at a higher risk of death compared to women with no hysterectomy (hazard ratio, 1.81; 95% confidence interval, 1.01-3.25).

CONCLUSION

Hysterectomy with ovarian conservation before the age of 50 years did not increase risk of all-cause mortality. Among nonmenopausal hormone therapy users only, hysterectomy and bilateral oophorectomy before the age of 50 years was associated with a higher risk of death.

Protective effect of hormone therapy among women with hysterectomy/oophorectomy

Study question

Does exposure to menopausal hormone therapy (MHT) in mid-aged women alter their risk of cardiovascular disease (CVD) mortality and all-cause mortality?

Summary answer

MHT soon after menopause is unlikely to increase the risk of CVD mortality or all-cause mortality and may have a protective effect for women with hysterectomy/oophorectomy.

What is known already

The balance of benefits and risks of MHT are currently unclear and may differ according to when treatment starts and whether women have an intact uterus.

Study design size, duration

A total of 13 715 participants from the mid-aged population-based cohort (born 1946-1951) of the Australian Longitudinal Study on Women's Health (ALSWH) were followed from 1998 to 2013.

Participants/materials setting methods

The measures included cardiovascular and all-cause mortality, exposure to MHT and menopausal status (based on 3-yearly self-reports). Electronic prescriptions data on MHT were also available from mid-2002 onwards. At each follow-up survey wave, participants were classified as: an existing user of MHT, an initiator of MHT or a non-initiator of MHT.

Main results and the role of chance

After adjusting for confounding variables, existing users of MHT had a reduced risk (hazard ratio 0.63; 95% CI, 0.43-0.92) of CVD mortality compared with non-initiators. Insufficient evidence of an association was identified for initiators of MHT (0.66; 0.35-1.24). For all-cause mortality, risks were reduced for both initiators (0.69; 0.55-0.87) and existing users (0.80; 0.70-0.91). In a subgroup analysis, women with hysterectomy/oophorectomy had lower risks of CVD mortality for both initiators (0.14; 0.02-0.98) and existing users (0.55; 0.34-0.90), but no evidence of an association was found for women whose MHT commenced during or after menopause. Similarly for all-cause mortality, only the women with hysterectomy/oophorectomy had lower risks for both initiators (0.47; 0.31-0.70) and existing users (0.69; 0.58-0.82).

Limitations, reasons for caution

Limitations include the observational nature of the study, the small number of deaths, MHT use being self-reported and the classification of menopausal status also being based on self-reported information.

Wider implications of the findings

Women considering MHT soon after menopause can be reassured that the treatment is unlikely to increase their risk of CVD mortality or all-cause mortality.

Study funding/competing interest(s)

The Australian Longitudinal Study on Women's Health is funded by the Australian Department of Health. G.D.M. is funded by the Australian Research Council Future Fellowship. L.C. was funded by a China scholarship council (CSC) graduate scholarship. All authors report no conflict of interest.

Trial registration number

N/A.

The fractions of cancer attributable to modifiable factors: A global review

Worldwide, the burden of cancer is rising, stimulating efforts to develop strategies to control these diseases. Primary prevention, a key control strategy, aims to reduce cancer incidence through programs directed towards reducing population exposure to known causal factors. Before enacting such strategies, it is necessary to estimate the likely effect on cancer incidence if exposures to known causal factors were reduced or eliminated. The population attributable fraction (PAF) is the epidemiological measure which quantifies this potential reduction in incidence. We surveyed the literature to document and summarise the proportions of cancers across the globe attributable to modifiable causes, specifically tobacco smoke, alcohol, overweight/obesity, insufficient physical activity, solar ultraviolet (UV) radiation and dietary factors (insufficient fruit, non-starchy vegetables and fibre; red/processed meat; salt). In total, we identified 55 articles that presented PAF estimates for one or more causes. Information coverage was not uniform, with many articles reporting cancer PAFs due to overweight/obesity, alcohol and tobacco, but fewer reporting PAFs for dietary factors or solar UV radiation. At all cancer sites attributable to tobacco and alcohol, median PAFs were markedly lower for women than men. Smoking contributed to very high median PAFs (>50%) for cancers of the lung and larynx. Median PAFs for men, attributable to alcohol, were high (25-50%) for cancers of the oesophagus, oral cavity/pharynx, larynx and liver. For cancers causally associated with overweight/obesity, high median PAFs were reported for oesophageal adenocarcinoma (men 29%, women 37%), gallbladder (men 11%, women 42%) and endometrium (36%). The cancer PAF literature is growing rapidly. Repeating this survey in the future should lead to more precise estimates of the potentially preventable fractions of cancer.

Cancers in Australia in 2010 attributable to insufficient physical activity

Objectives

To estimate the proportion and numbers of cancers occurring in Australia in 2010 attributable to insufficient levels of physical activity.

Methods

We estimated the population attributable fraction (PAF) of cancers causally associated with insufficient physical activity (colon, post-menopausal breast and endometrium) using standard formulae incorporating prevalence of insufficient physical activity (<60 minutes at least 5 days/week), relative risks associated with physical activity and cancer incidence. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that may have occurred assuming that everyone with insufficient activity levels increased their exercise by 30 minutes/week.

Results

An estimated 1,814 cases of colon, post-menopausal breast and endometrial cancer were attributable to insufficient levels of physical activity: 707 (6.5%) colon; 971 (7.8%) post-menopausal breast; and 136 (6.0%) endometrial cancers. If those exercising below the recommended level had increased their activity level by 30 minutes/week, we estimate 314 fewer cancers (17% of those attributable to insufficient physical activity) would have occurred in 2010.

Conclusions

More than 1,500 cancers were attributable to insufficient levels of physical activity in the Australian population.

Implications

Increasing the proportion of Australians who exercise could reduce the incidence of several common cancers.

Cancers in Australia in 2010 attributable to total breastfeeding durations of 12 months or less by parous women

Objectives

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to parous women having breastfed for total durations of ≤12 months.

Methods

We estimated the population attributable fraction (PAF) of breast cancers (the only cancer site with convincing evidence of causal association) associated with women breastfeeding for ≤12 months in total, using standard formulae incorporating breastfeeding prevalence data, relative risks associated with breastfeeding and cancer incidence. We also estimated the proportion change in disease incidence (potential impact fraction [PIF]) that might have occurred under two hypothetical scenarios of women breastfeeding for longer durations.

Results

An estimated 235 (1.7%) breast cancer cases that occurred in Australian in 2010 could be attributed to women breastfeeding for total durations of ≤12 months. Assuming a hypothetical increase in breastfeeding, we estimated that the number of breast cancers prevented would range from 36 to 51 (prevented fraction = 0.3% to 0.4%).

Conclusions

More than 200 breast cancers were attributable to women breastfeeding for total durations of ≤12 months.

Implications

Policies to increase breastfeeding duration may help prevent breast cancers in the future.

Cancers in Australia in 2010 attributable to modifiable factors: introduction and overview

OBJECTIVE

To describe the approach underpinning a national project to estimate the numbers and proportions of cancers occurring in Australia in 2010 that are attributable to modifiable causal factors.

METHODS

We estimated the population attributable fraction (PAF) (or prevented fraction) of cancers associated with exposure to causal (or preventive) factors using standard formulae. Where possible, we also estimated the potential impact on cancer incidence resulting from changes in prevalence of exposure. Analyses were restricted to factors declared causal by international agencies: tobacco smoke; alcohol; solar radiation; infectious agents; obesity; insufficient physical activity; insufficient intakes of fruits, vegetables and fibre; red and processed meat; menopausal hormone therapy (MHT); oral contraceptive pill (OCP); and insufficient breast feeding. Separately, we estimated numbers of cancers prevented by: aspirin; sunscreen; MHT; and OCP use. We discuss assumptions pertaining to latent periods between exposure and cancer onset, choices of prevalence data and risk estimates, and approaches to sensitivity analyses.

RESULTS

Numbers and population attributable fractions of cancer are presented in accompanying papers.

CONCLUSIONS

This is the first systematic assessment of population attributable fractions of cancer in Australia.

Cancers in Australia in 2010 attributable to infectious agents

OBJECTIVES

To estimate the proportion and numbers of cancers in Australia in 2010 attributable to infectious agents.

METHODS

The population attributable fraction (PAF) and number of cancers caused by hepatitis B and C viruses (HBV, HCV), Helicobacter pylori and human immunodeficiency virus (HIV) were calculated using standard formulae incorporating prevalence of infection in the Australian population, the relative risks associated with that infection and cancer incidence. For cancers with very strong associations to the infectious agent (Epstein-Barr virus [EBV], human papillomavirus [HPV] and HIV/Kaposi's sarcoma herpes virus [KSHV]), calculations were based on viral prevalence in the tumour.

RESULTS

An estimated 3,421 cancers (2.9% of all cancers) in Australia in 2010 were attributable to infections. Infectious agents causing the largest numbers of cancers were HPV (n=1,706), H. pylori (n=793) and HBV/HCV (n=518). Cancer sites with the greatest number of cancers caused by infections were cervix (n=818), stomach (n=694) and liver (n=483). Cancers with highest proportions attributable to infectious agents were Kaposi's sarcoma (100%), cervix (100%), nasopharynx (87%), anus (84%) and vagina (70%).

CONCLUSIONS

Infectious agents cause more than 3,000 cancers annually in Australia.

IMPLICATIONS

Opportunities for cancer prevention through infection control are considerable, even in a 'first world' nation like Australia.

Cancers in Australia attributable to exposure to solar ultraviolet radiation and prevented by regular sunscreen use

Objectives

To estimate the proportion and numbers of cancers occurring in Australia attributable to solar ultraviolet radiation (UVR) and the proportion and numbers prevented by regular sun protection factor (SPF) 15+ sunscreen use.

Methods

We estimated the population attributable fraction (PAF) and numbers of melanomas and keratinocyte cancers (i.e. basal cell carcinomas and squamous cell carcinomas) due to exposure to ambient UVR resulting from residing in Australia versus residing in the UK (for melanoma) or Scandinavia (for keratinocyte cancers). We also estimated the prevented fraction (PF): the proportion of cancers that would have occurred but were likely prevented by regular sunscreen use.

Results

An estimated 7,220 melanomas (PAF 63%) and essentially all keratinocyte cancers occurring in Australia were attributable to high ambient UVR levels in Australia. We estimated that regular sunscreen use prevented around 14,190 (PF 9.3%) and 1,730 (PF 14%) people from developing SCC and melanoma, respectively.

Conclusions

Although our approach was conservative, a high proportion of skin cancers in Australia are attributable to high ambient levels of UVR. Prevailing levels of sunscreen use probably reduced skin cancer incidence by 10–15%.

Implications

Most skin cancers are preventable. Sunscreen should be a component of a comprehensive sun protection strategy.

Cancers in Australia in 2010 attributable to and prevented by the use of menopausal hormone therapy

Objectives

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to menopausal hormone therapy (MHT) use.

Methods

We estimated the population attributable fraction for cancers causally associated with MHT (breast, endometrium, ovary), and the proportion of colorectal cancers prevented by MHT. We used standard formulae incorporating Australian prevalence data, relative risks of cancer associated with MHT and cancer incidence. We also estimated potential change in cancer incidence under two hypothetical scenarios whereby 25% fewer Australian women used MHT, or women exclusively used oestrogen-only MHT.

Results

An estimated 539 cancers in Australia in 2010 were attributable to MHT: 453 breast, 67 endometrial and 19 ovarian cancers equating to 3.4%, 3.1% and 1.6% of each cancer type, respectively. In contrast, MHT may have prevented 52 colorectal cancers. If 25% fewer women used MHT, then 141 cancers may have been avoided. If women exclusively used oestrogen-only MHT then 240 cancers may have been avoided.

Conclusions

MHT use caused more than 500 cancers in Australian women in 2010 and prevented ∼50 colorectal cancers.

Implications

MHT use continues to cause an excess of cancers. The risks, benefits, regimen and treatment duration should be carefully considered for each woman before MHT is commenced.

Cancers prevented in Australia in 2010 through the consumption of aspirin

Objectives

To estimate the proportion and number of cancers in Australia in 2010 that may have been prevented from occurring due to daily use of aspirin in the population.

Methods

We calculated the Prevented Fraction (PF) of colorectal and oesophageal cancers using standard formulae. The PF is the proportion of the hypothetical total load of cancer in the population that was prevented by exposure to aspirin. The formula incorporates estimates of the prevalence of aspirin use in Australian adult populations, the relative risks associated with aspirin use and cancer incidence.

Results

An estimated 335 colorectal cancers, 22 oesophageal adenocarcinomas and 29 oesophageal squamous cell carcinomas (SCC) were potentially prevented due to daily aspirin use. These figures equate to 2.2%, 3.1% and 5.4% of all colorectal cancers, oesophageal adenocarcinomas and oesophageal SCCs, respectively, that would otherwise have occurred but were potentially avoided due to the daily use of aspirin pertaining in the Australian population.

Conclusions

At current levels of consumption, a small but measurable reduction in cancer incidence can be attributed to daily aspirin use.

Implications

Assuming the benefits outweigh the harms of known gastrointestinal toxicity and other hazards, aspirin use may be considered for some people to prevent the development of particular gastrointestinal cancers.

Cancers in Australia in 2010 attributable to and prevented by the use of combined oral contraceptives

OBJECTIVES

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to combined oral contraceptive pill (OCP) use.

METHODS

We estimated the population attributable fraction (PAF) for cancers causally associated with combined OCP use (breast, cervix), and the proportion of endometrial and ovarian cancers prevented (prevented fraction [PF]). We used standard formulae incorporating prevalence of combined OCP use in the Australian population, relative risks of cancer associated with this exposure and cancer incidence.

RESULTS

An estimated 105 breast and 52 cervical cancers (0.7% and 6.4% of each cancer, respectively) in Australia in 2010 were attributable to current use of combined OCP. Past combined OCP use was estimated to have prevented 1,032 endometrial and 308 ovarian cancers in 2010, reducing the number of cancers that would otherwise have occurred by 31% and 19%, respectively.

CONCLUSIONS

A small proportion of breast and cervical cancers is attributable to combined OCP use; OCP use is likely to have prevented larger numbers of endometrial and ovarian cancers.

IMPLICATIONS

Women seeking contraceptive advice should be told of potential adverse effects, but should also be told that - along with reproductive health benefits - combined OCP use can reduce long-term risks of ovarian and endometrial cancers.

Cancers in Australia in 2010 attributable to modifiable factors: summary and conclusions

OBJECTIVE

To estimate the numbers and proportions of cancers occurring in Australia in 2010 attributable to modifiable causal factors.

METHODS

We estimated the population attributable fraction (PAF) of cancers associated with exposure to 13 causal factors using standard formulae incorporating exposure prevalence and relative risk data. We also calculated the potential impact of changing exposure to some factors.

RESULTS

A total of 32% of all cancers diagnosed in Australia in 2010 (excluding keratinocyte cancers) were attributable to the 13 factors assessed (men 33%; women 31%). Leading factors were tobacco smoke (PAF all cancers: 13.4%), solar radiation (6.2%), inadequate diet (6.1%) and overweight/obesity (3.4%). Factors conferring highest PAFs differed by sex: highest PAFs for men were tobacco smoke (15.8%), solar radiation (7.1%) and alcohol (3.0%); while highest PAFs for women were tobacco smoke (10.1%), solar radiation (5.0%) and overweight/obesity (4.5%). Sites with the highest counts of potentially preventable cancers were lung (8,569), colorectal (7,404), melanoma of the skin (7,220) and breast (3,233).

CONCLUSIONS

At least one in three cancers in Australia is attributable to exposure to known modifiable factors.

IMPLICATIONS

Up to 37,000 cancers could be prevented in Australia each year if the population avoided exposure to 13 common factors known or strongly suspected to cause cancer.

Cancers in Australia in 2010 attributable to the consumption of alcohol

OBJECTIVE

To estimate the proportion and numbers of cancers occurring in Australia in 2010 that are attributable to alcohol consumption.

METHODS

We estimated the population attributable fraction (PAF) of cancers causally associated with alcohol consumption using standard formulae incorporating prevalence of alcohol consumption and relative risks associated with consumption and cancer. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that might have occurred under the hypothetical scenario that an intervention reduced alcohol consumption, so that no-one drank >2 drinks/day.

RESULTS

An estimated 3,208 cancers (2.8% of all cancers) occurring in Australian adults in 2010 could be attributed to alcohol consumption. The greatest numbers were for cancers of the colon (868) and female breast cancer (830). The highest PAFs were for squamous cell carcinomas of the oral cavity/pharynx (31%) and oesophagus (25%). The incidence of alcohol-associated cancer types could have been reduced by 1,442 cases (4.3%)--from 33,537 to 32,083--if no Australian adult consumed >2 drinks/day.

CONCLUSIONS

More than 3,000 cancers were attributable to alcohol consumption and thus were potentially preventable.

IMPLICATIONS

Strategies that limit alcohol consumption to guideline levels could prevent a large number of cancers in Australian adults.

Cancers in Australia in 2010 attributable to inadequate consumption of fruit, non-starchy vegetables and dietary fibre

Objectives

To estimate the number and proportion of cancers occurring in Australia in 2010 attributable to consumption deficits in fruit, non-starchy vegetables and dietary fibre.

Methods

We estimated the population attributable fraction (PAF) for cancers causally associated with inadequate intake of fruit and non-starchy vegetables (oral cavity, pharynx, oesophageal squamous cell carcinoma, stomach, larynx); inadequate intake of fruit (lung); and insufficient intake of fibre (colorectum). We used standard formulae incorporating prevalence of exposure (1995 National Nutrition Survey) and relative risks from independent studies.

Results

Overall, 1,555 (1.4% of all) and 311 (0.3% of all) cancers were attributable to inadequate intakes of fruit and non-starchy vegetables, respectively. A further 2,609 colorectal cancers (18% of colorectal) were attributable to insufficient fibre intake. If Australians increased their fibre intake by eating the recommended daily intakes of fruit and vegetables, an estimated 1,293 (8.8%) colorectal cancers could be prevented.

Conclusions

One in six colorectal cancer cases was attributable to inadequate intake of dietary fibre and about 1,800 cancers at other sites were attributable to insufficient fruit and non-starchy vegetable consumption.

Implications

Increasing the proportion of Australians who consume the recommended intake of fruit, vegetables and fibre could prevent up to 4% of all cancers.

Cancers in Australia in 2010 attributable to the consumption of red and processed meat

Objectives

To estimate the proportion and numbers of cancers in Australia in 2010 attributable to consuming red/processed meat.

Methods

We estimated the population attributable fraction (PAF) for cancers causally associated with red/processed meat consumption (colon, rectum) using standard formulae incorporating prevalence of consumption (1995 National Nutrition Survey), relative risks associated with consumption and cancer incidence. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that might have occurred under two hypothetical interventions whereby Australian adults reduced their consumption of red/processed meat from prevailing levels to ≤100 g or ≤65 g per day, respectively.

Results

An estimated 2,614 cases (18%) of colorectal cancer occurring in Australians in 2010 were attributable to red/processed meat consumption (16% of colon cancers; 23% of rectal cancers). We estimated that if all Australian adults had consumed ≤65 g/day or ≤100 g/day of red/processed meat, then the incidence of colorectal cancer would have been 5.4% (798 cancers) or 1.4% (204 cancers) lower, respectively.

Conclusions

About one in six colorectal cancers in Australians in 2010 were attributable to red/processed meat consumption.

Implications

Reducing red/processed meat intake may reduce colorectal cancer incidence, but must be balanced against nutritional benefits of modest lean meat consumption.

Adolescents’ Attitudes About Obesity and What They Want in Obesity Prevention Programs

Obesity is a major pediatric public health problem. Adolescents are a priority population for intervention strategies. School nurses are in key positions to design intervention strategies to promote healthy lifestyles and prevent adolescent obesity in the students they serve. To design effective programs, school nurses need to know what components their students perceive as important. This study involved the development and administration of a questionnaire to middle school students to determine their attitudes about overweight/obesity and what they felt would work for them. Adolescents are willing to exercise more, to change eating habits to include more fruits and vegetables, drink more water, and eat less junk food. They are not willing to give up soda, video/computer games, and watching television to improve their health. School nurses can use this questionnaire to collect data that will assist in the development of effective programs for their students.

Age at Menarche, Level of Education, Parity and the Risk of Hysterectomy: A Systematic Review and Meta-Analyses of Population-Based Observational Studies

Background

Although rates have declined, hysterectomy is still a frequent gynaecological procedure. To date, there has been no systematic quantification of the relationships between early/mid-life exposures and hysterectomy. We performed a systematic review and meta-analyses to quantify the associations between age at menarche, education level, parity and hysterectomy.

Methods

Eligible studies were identified by searches in PubMed and Embase through March 2015. Study-specific estimates were summarised using random effects meta-analysis. Heterogeneity was explored using sub-group analysis and meta-regression.

Results

Thirty-two study populations were identified for inclusion in at least one meta-analysis. Each year older at menarche was associated with lower risk of hysterectomy—summary hazard ratio 0.86 (95% confidence interval: 0.78, 0.95; I² = 0%); summary odds ratio 0.88 (95% confidence interval: 0.82, 0.94; I² = 61%). Low education levels conferred a higher risk of hysterectomy in the lowest versus highest level meta-analysis (summary hazard ratio 1.87 (95% confidence interval: 1.25, 2.80; I² = 86%), summary odds ratio 1.51 (95% confidence interval: 1.35, 1.69; I² = 90%)) and dose-response meta-analysis (summary odds ratio 1.17 (95% confidence interval: 1.12, 1.23; I² = 85%) per each level lower of education). Sub-group analysis showed that the birth cohort category of study participants, the reference category used for level of education, the year the included article was published, quality of the study (as assessed by the authors) and control for the key variables accounted for the high heterogeneity between studies in the education level meta-analyses. In the meta-analyses of studies of parity and hysterectomy the results were not statistically significant.

Conclusions

The present meta-analyses suggest that the early life factors of age at menarche and lower education level are associated with hysterectomy, although this evidence should be interpreted with some caution due to variance across the included studies.

Cancers in Australia in 2010 attributable to tobacco smoke

OBJECTIVES

To estimate the population attributable fraction (PAF) and numbers of cancers occurring in Australia in 2010 attributable to tobacco smoking, both personal and by a partner.

METHODS

We used a modified Peto-Lopez approach to calculate the difference between the number of lung cancer cases observed and the number expected assuming the entire population developed lung cancer at the same rate as never smokers. For cancers other than lung, we applied the standard PAF formula using relative risks from a large cohort and derived notional smoking prevalence. To estimate the PAF for partners' smoking, we used the standard formula incorporating the proportion of non-smoking Australians living with an ever-smoking partner and relative risks associated with partner smoking.

RESULTS

An estimated 15,525 (13%) cancers in Australia in 2010 were attributable to tobacco smoke, including 8,324 (81%) lung, 1,973 (59%) oral cavity and pharynx, 855 (60%) oesophagus and 951 (6%) colorectal cancers. Of these, 136 lung cancers in non-smokers were attributable to partner tobacco smoke.

CONCLUSIONS

More than one in eight cancers in Australia is attributable to tobacco smoking and would be avoided if nobody smoked.

IMPLICATIONS

Strategies to reduce the prevalence of smoking remain a high priority for cancer control.

Cancers in Australia in 2010 attributable to overweight and obesity

OBJECTIVES

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to overweight/obesity.

METHODS

We estimated the population attributable fraction (PAF) and number of cancers causally associated with overweight/obesity. We used standard formulae incorporating Australian prevalence data for body mass index (BMI), relative risks associated with BMI and cancer. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that may have occurred assuming that the prevalence of overweight/obesity had remained at 1990 levels.

RESULTS

An estimated 3,917 cancer cases (3.4% of all cancers) diagnosed in 2010 were attributable to overweight/obesity, including 1,101 colon cancers, 971 female post-menopausal breast cancers and 595 endometrial cancers (PAFs of 10%, 8% and 26%, respectively). Highest PAFs were observed for oesophageal adenocarcinoma (31%), endometrial cancer (26%) and kidney cancer (19%). If the prevalence of overweight/obesity in Australia had remained at levels prevailing in 1990, we estimate there would have been 820 fewer cancers diagnosed in 2010 (PIF 2%).

CONCLUSIONS

Overweight/obesity causes a substantial number of cancers in Australia.

IMPLICATIONS

Public health strategies to reduce the prevalence of overweight and obesity will reduce the incidence of cancer, particularly of the colon, breast and endometrium.

A simulation design for research evaluating safety innovations in anaesthesia*

SUMMARY

It is notoriously difficult to obtain evidence from clinical randomised controlled trials for safety innovations in healthcare. We have developed a research design using simulation for the evaluation of safety initiatives in anaesthesia. We used a standard and a modified scenario in a human-patient simulator, involving a potentially life-threatening problem requiring prompt attention--either a cardiac arrest or a failure in oxygen supply. The modified scenarios involved distractions such as loud music, a demanding and uncooperative surgeon, telephone calls and frequent questions from a medical student. Twenty anaesthetics were administered by 10 anaesthetists. A mean (SD) of 11.3 (2.8) errors per anaesthetic were identified in the oxygen failure scenarios, compared with 8.0 (3.4) in the cardiac arrest scenarios (ANOVA: p = 0.04). The difference between the combined standard scenarios and the combined modified scenarios was not significant. The mean rate of errors overall was 9.7 per simulation, with a pooled SD of 4.46, so in future studies 21 subjects would provide 80% statistical power to show a reduction in error rate of 30% from baseline with p<or=0.05. Our research design will facilitate the evaluation of safety initiatives in anaesthesia.

The radiological appearances of thalassaemia

The skeletal changes of untreated thalassaemia result from ineffective erythropoiesis and expansion of the bone marrow and affect every part of the skeleton. These changes include osteoporosis, growth retardation, platyspondyly and kyphosis. Erythropoiesis occurs at extra-medullary sites, most commonly resulting in a paraspinal mass but occasionally affecting organs containing pluripotential stem cells. Repeated transfusion unaccompanied by iron chelation causes haemosiderosis; iron is deposited at various sites causing functional impairment. Iron-chelation therapy with desferrioxamine (DFX) prevents haemosiderosis but causes a skeletal dysplasia predominantly affecting the rapidly growing long bones, in particular the distal ulna, and causing irregularity and sclerosis of the physeal-metaphyseal junction and splaying of the metaphysis. DFX also exacerbates the observed growth retardation. DFX-induced skeletal dysplasia may herald toxicity, which is associated with visual and auditory impairment. Therefore, careful balancing of the transfusion regimen and iron-chelation therapy is required. Magnetic resonance imaging (MRI) is the most sensitive technique for the detection of DFX-induced dysplasia.

L5 Radiculopathy Secondary to Intrapelvic Placement of Acetabular Cup Fixation Screw

We report a case of L5 radiculopathy secondary to intrapelvic placement of an acetabular screw impinging on the lumbosacral trunk. A 43-year-old man underwent revision of an uncemented total hip replacement to a custom-made femoral component and uncemented cup. He subsequently developed hip pain, dysesthesia, and L5 radiculopathy. Spiral computed tomography (CT) and plain radiographs raised the possibility of an acetabular screw abutting the neurovascular bundle within the pelvis. Operative removal of the intrapelvic portion of the screw resulted in the immediate relief of the patient's radicular symptoms. This case report highlights the importance of the positioning of intrapelvic screws and the need for an anatomic awareness of the structures at risk during acetabular screw placement.

"Pig Tail" technique in intradiscal electrothermal therapy

To describe a new method of catheter insertion in intradiscal electrothermal therapy, which eliminates the need for reinsertion of the cannula and catheter from the contralateral side in those patients in whom optimal positioning is not achieved with the standard technique. This new technique has not been described before. In those patients in whom adequate catheter position cannot be achieved with the standard technique, instead of withdrawing the cannula after the initial treatment, we recommend rotating the cannula 180 degrees through its long axis. This will allow the catheter to hit the anterior anulus and deflect backwards toward the cannula. It can then be negotiated across the midline to adequately thermally treat the whole posterior anulus. We have performed our technique in 42 consecutive patients in whom initial navigation was difficult. This new method proved to be simple and did not cause patients additional discomfort. The "pig tail" technique is safe and effective in intradiscal electrothermal therapy of those patients with difficult navigation. It avoids the need for second needle insertion, therefore avoiding the use of more local anesthesia, further discomfort for the patient, and additional radiographic exposure.

High-intensity zone, intradiscal electrothermal therapy, and magnetic resonance imaging

Magnetic resonance imaging changes to the symptomatic intervertebral disc following intradiscal electrothermal therapy were determined in this prospective study. Magnetic resonance images before the intradiscal electrothermal therapy procedure were compared with those taken at 6 months postprocedure in 10 patients. The presence and absence of high-intensity zone, the disc height and hydration, and Modic changes were determined from the images. In six of the 10 patients, a high-intensity zone was present on the magnetic resonance images of the disc before the intradiscal electrothermal therapy procedure. In all six patients, a high-intensity zone was still present after the procedure. In all 10 patients, there were no changes to other disc parameters assessed. Our findings question the clinical relevance of the high-intensity zone. They also suggest that the main mechanism of action of intradiscal electrothermal therapy may be other than that of sealing the anular tear.

Adolescent disc protrusions. A long-term follow-up of surgery compared to chymopapain

STUDY DESIGN

This study compared chymopapain with primary surgery in the treatment of 60 radiologically proven adolescent lumbar disc protrusions and symptoms of low back pain and sciatica; the failures of intradiscal therapy were treated by surgical discectomy.

OBJECTIVES

To establish whether chymopapain is as good as primary surgery in treating adolescents with proven lumbar disc protrusions.

SUMMARY OF BACKGROUND DATA

Symptomatic lumbar disc protrusions are rare in white adolescents; the reported incidence varies from 0.8% to 3.2% of all lumbar disc protrusions. This is the largest study with long-term follow-up in the world literature.

METHODS

Forty-two patients between the ages of 13 and 19 years with proven lumbar disc protrusions were initially treated with chymopapain; the failures of intradiscal therapy were treated by surgical discectomy. Eighteen patients were treated with surgical discectomy. After initial review at 1, 3, 6, and 12 months, the patients were assessed using a postal questionnaire and telephone interview at a minimum of 5 years' follow-up (means: 8.5 years for chymopapain group, 7.2 years for surgery group).

RESULTS

Full replies were received from 16 of 18 (89%) in the surgery group and 42 of 42 (100%) in the chymopapain group. The long-term outcome is classed as good or excellent in 81% of the surgical group and 64% in the chymopapain group. If chymopapain is used as a first-line treatment, with surgery reserved for the failures, the long-term outcome is good or excellent in 82%. The chymopapain group had a shorter hospital stay. The surgical group were more likely to be unemployed and were less able to perform manual work and less able to engage in sporting activity.

CONCLUSIONS

Back pain, radicular pain, and tension signs are common, but neurologic signs are less frequent in this age group. Long-term results of surgery are no better than the results of first-line chymopapain treatment with surgery being reserved for the failures. In 60% to 70% of patients, the morbidity, cost, and hospital stay were lessened. The patient is more likely to be in satisfactory employment after chemonucleolysis than after primary surgery.

Holoprosencephaly and midline facial anomalies: redefining classification and management

Holoprosencephaly encompasses a series of midline defects of the brain and face. Most cases are associated with severe malformations of the brain which are incompatible with life. At the other end of the spectrum, however, are patients with midline facial defects and normal or near-normal brain development. Although some are mentally retarded, others have the potential for achieving near-normal mentality and a full life expectancy. The latter patients do not fit clearly into the previously defined classification system. Proposed is a new classification focusing on those patients with normal or lobar brain morphology but with a wide range of facial anomalies. The classification aids in planning treatment. Coupled with CT scan findings of the brain and a period of observation, patients unlikely to thrive can be distinguished from those who will benefit from surgical intervention. Repair of the false median cleft lip and palate may suffice in patients with moderate mental retardation. Patients exhibiting normal or near-normal mentality with hypotelorbitism and nasomaxillary hypoplasia can be treated with a simultaneous midface advancement, facial bipartition expansion, and nasal reconstruction.