Gendered experiences of unemployment, suicide and self-harm: a population-level record linkage study.

BACKGROUND: Unemployment and being not in the labour force (NILF) are risk factors for suicide, but their association with self-harm is unclear, and there is continuing debate about the role of confounding by prior mental health conditions. We examine associations between employment status and self-harm and suicide in a prospective cohort, taking into account prior mental-health-related factors. METHODS: We used linked data from the New Zealand Integrated Data Infrastructure. The outcomes were chosen to be hospital presentation for self-harm and death by suicide. The exposure was employment status, defined as employed, unemployed, or NILF, measured at the 2013 Census. Confounders included demographic factors and mental health history (use of antidepressant medication, use of mental health services, and prior self-harm). Logistic regression was used to model effects. Analyses were stratified by gender. RESULTS: For males, unemployment was associated with an increased risk of suicide [odds ratio (OR): 1.48, 95% confidence interval (CI): 1.20-1.84] and self-harm (OR: 1.55, 95% CI: 1.45-1.68) after full adjustment for confounders. NILF was associated with an increased risk of self-harm (OR: 1.43, 95% CI: 1.32-1.55), but less of an association was seen with suicide (OR: 1.19, 95% CI: 0.94-1.49). For females, unemployment was associated with an increased risk of suicide (OR: 1.30, 95% CI: 0.93-1.80) and of self-harm (OR: 1.52, 95% CI: 1.43-1.62), and NILF was associated with a similar increase in risk for suicide (OR: 1.31, 95% CI: 0.98-1.75) and self-harm (OR: 1.32, 95% CI: 1.26-1.40). DISCUSSION: Exclusion from employment is associated with a considerably heightened risk of suicide and self-harm for both men and women, even among those without prior mental health problems.

Exposure to discrimination and subsequent changes in self-rated health: prospective evidence from the UK's Life Opportunities Survey.

OBJECTIVES: We sought to estimate risk of poor self-rated health (SRH) following exposure to disability-related and other forms of overt discrimination in a cohort of working age adults. STUDY DESIGN: The study design is a population-based cohort survey. METHODS: Secondary analysis of data collected in Waves 1 and 2 of the UK's Life Opportunities Survey which at Wave 2 involved the participation of 12,789 working age adults. Adjusted prevalence rate ratios were used to estimate the impact of exposure to disability and non-disability discrimination on two measures of SRH at Wave 2, controlling for SRH status at Wave 1. RESULTS: Exposure to disability discrimination in the previous year was reported by 3.9% of working age British adults. Other forms of discrimination were reported less frequently (age: 3.7%, ethnicity: 2.5%, gender: 1.6%, religion: 0.8%, sexual orientation: 0.4%). In all analyses, there were stronger associations between exposure to disability discrimination and poor SRH at Wave 2 when compared with exposure to other forms of discrimination. CONCLUSIONS: Disability discrimination represents a violation of human rights. It is also likely to be a major contributor to the health inequities experienced by working age adults with disability.

Disabling working environments and mental health: A commentary.

Employment is a fundamental Social Determinant of Health known to have large impacts on mental health and other health outcomes. Across many countries of the world, people with disabilities are much more likely to be unemployed and looking for work than those without disabilities. The deprivation of employment opportunities is likely to have notable impacts on the health of people with disabilities. In this commentary, we outline the concept of "disabling working environments," which are defined as the range of experiences that affect the likelihood of people with disabilities in obtaining and maintaining quality employment which may then affect a disabled person's health. Disabling working environments are comprised of the following three mutually reinforcing components: 1) Differential selection into work; 2) Selection into certain types of jobs and exposure to poor psychosocial working environments when in employment, and; 3) Differential selection out of work (e.g., leaving employment at an earlier age than those who do not have a disability). We argue that policy and intervention design should consider the life course effects of employment on the mental health of people with disabilities.

Employment status and mental health among persons with and without a disability: evidence from an Australian cohort study.

BACKGROUND: Unemployment and economic inactivity are associated with worse mental health in the general population, but there is limited understanding of whether these relationships are different for those persons with mental or physical disabilities. The aim of this study was to assess whether there were differences in mental health by labour force status among persons with and without disabilities. METHOD: Over eight annual waves of the Household, Income and Labour Dynamics in Australia (HILDA) survey, a total of 2379 people with disabilities and 11 417 people without disabilities were identified. Mental health using the Mental Component Summary (MCS) from the Short Form 36 was modelled as a function of labour force status using fixed-effects regression models to control for time invariant confounding. Differences between those with and without disabilities were assessed by including an interaction term in regression models. RESULTS: After finding evidence of effect modification, regression models were stratified by disability status. After adjustment, unemployment and economic inactivity were associated with a -1.85 (95% CI -2.96 to -0.73, p=0.001) and -2.66 (95% CI -3.46 to -1.86, p<0.001) reduction in scores of the MCS among those with a disability. For those without a disability, there were smaller declines associated with unemployment (-0.57, 95% CI -1.02 to -0.12, p=0.013) and economic inactivity (-0.34, 95% CI -0.64 to 0.05, p=0.022). CONCLUSIONS: These results suggest a greater reduction in mental health for those persons with disabilities who were unemployed or economically inactive than those who were employed. This highlights the value of employment for people with disabilities.

Psychosocial working conditions in a representative sample of working Australians 2001-2008: an analysis of changes in inequalities over time.

BACKGROUND: A number of widely prevalent job stressors have been identified as modifiable risk factors for common mental and physical illnesses such as depression and cardiovascular disease, yet there has been relatively little study of population trends in exposure to job stressors over time. The aims of this paper were to assess: (1) overall time trends in job control and security and (2) whether disparities by sex, age, skill level and employment arrangement were changing over time in the Australian working population. METHODS: Job control and security were measured in eight annual waves (2000-2008) from the Australian nationally-representative Household Income and Labour Dynamics of Australia panel survey (n=13 188 unique individuals for control and n=13 182 for security). Observed and model-predicted time trends were generated. Models were generated using population-averaged longitudinal linear regression, with year fitted categorically. Changes in disparities over time by sex, age group, skill level and employment arrangement were tested as interactions between each of these stratifying variables and time. RESULTS: While significant disparities persisted for disadvantaged compared with advantaged groups, results suggested that inequalities in job control narrowed among young workers compared with older groups and for casual, fixed-term and self-employed compared with permanent workers. A slight narrowing of disparities over time in job security was noted for gender, age, employment arrangement and occupational skill level. CONCLUSIONS: Despite the favourable findings of small reductions in disparities in job control and security, significant cross-sectional disparities persist. Policy and practice intervention to improve psychosocial working conditions for disadvantaged groups could reduce these persisting disparities and associated illness burdens.

Association between fast food purchasing and the local food environment.

OBJECTIVE: In this study, an instrument was created to measure the healthy and unhealthy characteristics of food environments and investigate associations between the whole of the food environment and fast food consumption. DESIGN AND SUBJECTS: In consultation with other academic researchers in this field, food stores were categorised to either healthy or unhealthy and weighted (between +10 and -10) by their likely contribution to healthy/unhealthy eating practices. A healthy and unhealthy food environment score (FES) was created using these weightings. Using a cross-sectional study design, multilevel multinomial regression was used to estimate the effects of the whole food environment on the fast food purchasing habits of 2547 individuals. RESULTS: Respondents in areas with the highest tertile of the healthy FES had a lower likelihood of purchasing fast food both infrequently and frequently compared with respondents who never purchased, however only infrequent purchasing remained significant when simultaneously modelled with the unhealthy FES (odds ratio (OR) 0.52; 95% confidence interval (CI) 0.32-0.83). Although a lower likelihood of frequent fast food purchasing was also associated with living in the highest tertile of the unhealthy FES, no association remained once the healthy FES was included in the models. In our binary models, respondents living in areas with a higher unhealthy FES than healthy FES were more likely to purchase fast food infrequently (OR 1.35; 95% CI 1.00-1.82) however no association was found for frequent purchasing. CONCLUSION: Our study provides some evidence to suggest that healthier food environments may discourage fast food purchasing.

Invasive breast cancers detected by screening mammography: a detailed comparison of computer-aided detection-assisted single reading and double reading.

To compare double reading plus arbitration for discordance, (currently best practice, (BP)) with computer-aided-detection (CAD)-assisted single reading (CAD-R) for detection of invasive cancers detected within BreastScreen Australia. Secondarily, to examine characteristics of cancers detected/rejected using each method. Mammograms of 157 randomly selected double-read invasive cancers were mixed 1:9 with normal cancers (total 1569), all detected in a BreastScreen service. Cancers were detected by two readers or one reader (C2 and C1 cancers, ratio 70:30%) in the program. The 1569 film-screen mammograms were read by two radiologists (reader A (RA) and reader B(RB)), with findings recorded before and after CAD. Discordant findings with BP were resolved by arbitration. We compared CAD-assisted reading (CAD-RA, CAD-RB) with BP, and CAD and arbitration contribution to findings. We correlated cancer size, sensitivity and mammographic density with detection methods. BP sensitivity 90.4% compared with CAD-RA sensitivity 86.6% (P = 0.12) and CAD-RB 94.3% (P = 0.14). CAD-RB specificity was less than BP (P = 0.01). CAD sensitivity was 93%, but readers rejected most positive CAD prompts. After CAD, reader's sensitivity increased 1.9% and specificity dropped 0.2% and 0.8%. Arbitration decreased specificity 4.7%. Receiving operator curves analysis demonstrated BP accuracy better than CAD-RA, borderline significance (P = 0.07), but not CAD-RB. Secondarily, cancer size was similar for BP and CAD-R. Cancers recalled after arbitration (P = 0.01) and CAD-R (P = 0.10) were smaller. No difference in cancer size or sensitivity between reading methods was found with increasing breast density. CAD-R and BP sensitivity and cancer detection size were not significantly different. CAD-R specificity was significantly lower for one reader.

Area variation in recreational cycling in Melbourne: a compositional or contextual effect?

OBJECTIVE: To examine whether compositional and/or contextual area characteristics are associated with area socioeconomic inequalities and between-area differences in recreational cycling. SETTING: The city of Melbourne, Australia. PARTICIPANTS: 2349 men and women residing in 50 areas (58.7% response rate). MAIN OUTCOME MEASURE: Cycling for recreational purposes (at least once a month vs never). DESIGN: In a cross-sectional survey participants reported their frequency of recreational cycling. Objective area characteristics were collected for their residential area by environmental audits or calculated with Geographic Information Systems software. Multilevel logistic regression models were performed to examine associations between recreational cycling, area socioeconomic level, compositional characteristics (age, sex, education, occupation) and area characteristics (design, safety, destinations or aesthetics). RESULTS: After adjustment for compositional characteristics, residents of deprived areas were less likely to cycle for recreation (OR 0.66; 95% CI 0.43 to 1.00), and significant between-area differences in recreational cycling were found (median odds ratio 1.48 (95% credibility interval 1.24 to 1.78). Aesthetic characteristics tended to be worse in deprived areas and were the only group of area characteristics that explained some of the area deprivation differences. Safety characteristics explained the largest proportion of between-area variation in recreational cycling. CONCLUSION: Creating supportive environments with respect to safety and aesthetic area characteristics may decrease between-area differences and area deprivation inequalities in recreational cycling, respectively.

Weight and place: a multilevel cross-sectional survey of area-level social disadvantage and overweight/obesity in Australia.

OBJECTIVE: To estimate variation between small areas in adult body mass index (BMI), and assess the importance of area level socioeconomic disadvantage in predicting BMI. METHODS: We identified all census collector districts (CCDs) in the 20 innermost Local Government Areas in metropolitan Melbourne, Australia, and ranked them by the percentage of low income households (< dollar 400/week). In all, 50 CCDs were randomly selected from the least, middle and most disadvantaged septiles of the ranked list and 4913 residents (61.4% participation rate) completed one of two surveys. Multilevel linear regression was used to estimate area level variance in BMI and the importance of area level socioeconomic disadvantage in predicting BMI. RESULTS: There were significant variations in BMI between CCDs for women, even after adjustment for individual and area SES (P = 0.012); significant area variation was not found for men. Living in the most versus least disadvantaged areas was associated with an average difference in BMI of 1.08 kg/m2 (95% CI: 0.48-1.68 kg/m2) for women, and of 0.93 kg/m2 (95% CI: 0.32-1.55 kg/m2) for men. Living in the mid versus least disadvantaged areas were associated with an average difference in BMI of 0.67 kg/m2 (95% CI: 0.09-1.26 kg/m2) for women, and 0.43 kg/m2 for men (95% CI: -0.16-1.01). CONCLUSION: These findings suggest that area disadvantage is an important predictor of adult BMI, and support the need to focus on improving local environments to reduce socioeconomic inequalities in overweight and obesity.

Determinants of false positive recall in an Australian mammographic screening program.

We conducted a case-control study (n=30128) to assess the importance of clinical (e.g., family history, age, hormone replacement therapy (HRT) use and duration) and service-related characteristics (e.g., time since introduction of Kodak MINR2000 film, year of screen) for false positive (FP) recall at BreastScreen Victoria, Australia. There was an age-adjusted upward trend in FP recall rates with year of screen at first (odds ratio (OR) 1.11, 95% confidence interval (95% CI) 1.08-1.13) and subsequent rounds (OR 1.04, 95% CI 1.01-1.06). In the multivariate analysis, the upward trend only remained for first round and age and family history also remained statistically significant at first round. At subsequent rounds the time since introduction of MINR2000, age, strong family history of breast cancer, use of HRT, recall at previous screen and previous screen at more than 27 months were all important predictors of FP recall. The rise in FP rates with year of screen at first round screening is of concern and may require further training of radiologists to improve confidence when viewing films when there a no films for comparison.

Use of hormone replacement therapy (HRT) and survival following breast cancer diagnosis.

Although hormone replacement therapy (HRT) use has been associated with breast cancers that have better prognostic features, it is not clear whether this leads to improved survival. We studied a cohort of 4022 postmenopausal women diagnosed with breast cancer between 1993 and 2000, who attended a mammographic screening program, among whom 312 deaths subsequently occurred. Proportional hazards models were used to examine survival from breast cancer and all-causes among HRT users and non-users. The multivariate hazard ratio for HRT use was 0.64 (95% CI: 0.41-1.00) for breast cancer deaths and 0.69 (95% CI: 0.49-0.96) for all-cause mortality. This was attenuated by grade (HR 0.71; 95% CI: 0.45-1.10). HRT use at diagnosis was associated with modestly improved survival from breast cancer that appeared in part to be explained by the influence of HRT on tumour grade, although we cannot exclude the possibility of confounding by factors associated with the choice to use HRT.

Invasive lobular carcinoma: sonographic features of cancers detected in a BreastScreen Program.

Sixty-two screen-detected invasive lobular carcinomas (ILC) were studied for sonographic, mammographic, clinical and histological findings. Ultrasound (US) features were compared with 60 invasive duct cancers (IDC). Size and axillary lymph node status in ILC were compared with all other cancers detected. In 41 ILC examined with US, 36 were found as masses (87.8% sensitivity; 95% CI 77.8-97.8%). Some US features of ILC and IDC differed: ILC were 9.94 times more likely to be hyperechoic (odds ratio, OR, 9.94; 95% CI 3.28-31.74) and 77% less likely to be taller than wide (OR 0.23; 95% CI 0.18-0.62). Thirty-three ILC showed typical malignant features of spiculate margins and acoustic shadowing. invasive lobular carcinomas had a greater mean diameter (20.4 mm; n = 60) than other invasive cancers (14.4 mm; n = 322) (P < 0.001). Ultrasound-guided needle biopsy was the method of diagnosis in 26 of 41 impalpable ILC (63%). Ultrasound has high sensitivity in characterizing screen-detected ILC, which may have atypical sonographic features including hyperechogenicity and a wider than tall shape. Ultrasound was an important contributor to diagnosis.

Management of women with minor abnormalities of the cervix detected on screening: a qualitative study.

OBJECTIVE: To examine the consistency of decisions by pathology staff and general practitioners in managing women in whom minor cervical abnormalities are detected by screening, with current National Health and Medical Research (NHMRC) Council guidelines, and to look at reasons for inconsistencies. DESIGN: Qualitative interview study. PARTICIPANTS: 14 pathology staff (12 pathologists and two cytoscientists) from 10 of the 17 laboratories providing cervical cytology services in Victoria, and a sample of 22 GPs from metropolitan and rural locations in Victoria. MAIN OUTCOME MEASURES: Comparison of management practice with NHMRC guidelines; reasons for current decision-making practice. RESULTS: Most pathologists provided more cautious recommendations for minor abnormalities of the cervix than the NHMRC recommendations in all reporting categories except human papillomavirus. Pathologists had concerns about the appropriateness of the NHMRC recommendations, particularly for glandular atypia, lack of an endocervical component and inflammatory smears, where they believed that the NHMRC recommendations were not well supported by evidence. GPs generally followed the recommendations of their laboratories. Medicolegal concerns were a major influence on clinical decisions for both pathologists and GPs, and have contributed to the development of cautious management practice. Reporting and management practice of pathologists and GPs reflects the ambiguity of minor cervical abnormalities that the NHMRC guidelines fail to highlight. CONCLUSION: Many pathologists and GPs are reluctant to follow NHMRC guidelines because they believe they are inadequate for some minor cervical abnormalities. The cervical screening guidelines should be reviewed according to the NHMRC guidelines for developing clinical practice guidelines, to promote consistent practice based on an up-to-date, accurate evidence base.

The sensitivity, specificity, and positive predictive value of screening mammography and symptomatic status.

OBJECTIVE: To examine whether the accuracy of screening mammography varies according to symptomatic status reported at the time of screening. SETTING: Victoria, Australia, where free biennial screening is provided to women aged 40 and older. METHODS: We examined the sensitivity, specificity, and the positive predictive value of screening mammography by symptom status in 106,826 women from Victoria, who attended for first round mammography in 1994 and who did not have a personal history of breast cancer. Symptomatic status was divided into the following categories: asymptomatic; significant symptoms, if the woman reported a breast lump and/or blood stained or watery nipple discharge; and other symptoms, if reported. Unconditional logistic regression modelling was used to adjust for age, use of hormone replacement therapy (HRT), and family history. RESULTS: Sensitivity was lower for women with other symptoms (60.0%) than asymptomatic women (75.6%), or women with significant symptoms (80.8%). Specificity was lower for women with significant symptoms (73.7%) than asymptomatic women (94.9%), or women with other symptoms (95.4%). Among women who had invasive cancer detected during screening interval, women with other symptoms were more likely to get a false negative result (odds ratio 1.79, 95% confidence interval 1.03 to 3.04) than asymptomatic women, after adjusting for age, use of HRT, and family history. CONCLUSION: The lower sensitivity in women with other symptoms requires further investigation. Possible explanations include increased breast density and poor image quality. The high sensitivity in women with significant symptoms is probably due to more cautious radiological practice, which has also resulted in low specificity in this group.

Hormone replacement therapy and accuracy of mammographic screening.

BACKGROUND: Hormone replacement therapy (HRT) is commonly used and may affect the accuracy of mammographic screening. METHODS: We examined the sensitivity, specificity, and small-cancer detection rate according to HRT use in 103,770 women in Victoria, Australia, who attended first-round screening in 1994 and who did not have a personal history of breast cancer or a breast lump or a bloodstained or watery nipple discharge at the time of screening. BreastScreen Victoria provides mammography to women aged 40 years and older every 2 years. Unconditional logistic modelling was used to adjust for age, family history, and symptom status. FINDINGS: The sensitivity of screening mammography for a 2-year screening interval was lower in HRT users (64.8% [95% CI 58-72]) than non-users (77.3% [74-81]). In the target group (50-69 years), the sensitivity was 64.3% (57-72) in HRT users and 79.8% (76-84) in non-users. Among women who were diagnosed with cancer during the 2-year screening interval, HRT users were more likely to have a false negative result than non-users (odds ratio 1.60 [1.04-2.21]) after adjusting for potential confounding factors. Specificity was 0.6% lower in HRT users compared with non-users. Among women who did not have cancer diagnosed in the interval, HRT users were more likely to have a false positive result (adjusted odds ratio 1.12 [1.05-1.19]). INTERPRETATION: We show that HRT use reduces the sensitivity of mammographic screening. In countries where HRT use is widespread, the reduction in sensitivity with HRT use may undermine the capacity of population-based mammographic-screening programmes to realise their potential mortality benefit.

Predictors of non-attendance for second round mammography in an Australian mammographic screening programme.

OBJECTIVE: To determine the socioeconomic, cultural, and clinical predictors of non-attendance for second round mammography. DESIGN/PARTICIPANTS: Retrospective cohort study of 121 889 women aged 50-69 years who attended for first mammography screening in the BreastScreen Victoria programme in 1995/1996 and who were recommended to be invited for routine biennial mammography. Women were considered to be non-attenders if they had not attended for rescreening within 27 months of their initial screening. Relative risk (RR) was used to compare categories for non-attendance for second screening, and a multivariate model was fitted to adjust for possible confounding. SETTING: BreastScreen Victoria, a population based mammographic screening programme, which offers free biennial mammography to all women 40 years and older. The programme specifically targets women aged 50-69 years. RESULTS: In the multivariate analysis, women from non-English speaking backgrounds were more likely not to attend for second round screening (RR ranged from 1.18 to 1.77). Indigenous women (RR 2.02, 95% confidence interval (CI) 1.61 to 2.54) and women who reported either significant symptoms (RR 1.90, 95% CI 1.76 to 2.05) or other breast symptoms (RR 2.25, 95% CI 2.15 to 2.36) at the time of first round screening were also more likely not to attend for second round screening. CONCLUSIONS: Women from non-English speaking backgrounds, indigenous women, and women who report symptoms at the time of first screening are more likely to not attend for second round screening. It is important to investigate why these women do not attend for second round screening so that services can be more appropriately tailored to their needs.

Radiological review of interval cancers in an Australian mammographic screening programme. Radiology Quality Assurance Group of BreastScreen Victoria.

OBJECTIVES: To determine the proportion and features of invasive interval cancers that could be considered detectable at the time of the previous screen and the proportion of cases that could be classified as true intervals, false negatives, minimal signs, or radiographically occult lesions. SETTING: BreastScreen Victoria, the Victorian component of the BreastScreen Australia mammography screening programme. METHODS: Two separate review methodologies were adopted. Firstly a blinded review of interval, screen detected, and normal cases was undertaken, followed by a confirmation exercise to determine the proportion of invasive interval cancers that could be considered detectable at the time of the previous screen. Secondly, an unblinded review was performed to classify interval cases as true interval, false negative, minimal signs, or radiographically occult. RESULTS: From the blinded review, it was estimated that 38% of interval cases may be considered "potentially detectable" at the time of screening. Comparison of the characteristics of interval and screen detected cases indicates that interval cases are more likely to be smaller, equivocal, ill defined masses. In the unblinded exercise, 41% of interval cases were classified as false negatives and a further 16% as minimal signs, 33% true intervals, and 10% radiographically occult. Of the interval cancers considered potentially detectable at screening, 97% were classified as false negatives in the unblinded review. CONCLUSIONS: This study highlights the importance of adopting staged review methods with both blinded and unblinded components. The blinded review and confirmation exercise allows the determination of the proportion of interval cases that could be considered potentially detectable at screening. The unblinded review provides an active important opportunity for professional development and review and a mechanism to link into the blinded review through further classification of interval cases.

Monitoring interval cancers in an Australian mammographic screening programme.

OBJECTIVE: To report the interval cancer rate for BreastScreen Victoria. DESIGN: Electronic linkage of Breast Screen Victoria records with those of the Victorian Cancer Registry. Interval cancers were expressed as a proportion of the underlying incidence (proportional incidence), and the sensitivity as the number of screen detected invasive breast cancers divided by the total number of invasive breast cancers diagnosed in the screening interval. SETTING: Victoria, Australia where biennial screening is provided to women aged 40 and older. SUBJECTS: Victorian women aged 40-79 who attended first round screening in 1994 (103,023 women) and 1995 (107,057 women). RESULTS: The sensitivity of screening mammography for the two year interval increased with age (p for trend < 0.001) and was 49.4% in women aged 40-49, 68.6% in 50-59 year old women, 80.7% in 60-69 year old women, and 85.2% in women aged 70-79. The proportional incidence in the first year after screening was 59% in 40-49 year old women and 27% in women aged 50-69. In the second year the proportional incidence was 93% in 40-49 year old women and 54% in women aged 50-69. CONCLUSIONS: Interval cancers comprise such a large proportion of the expected number of cancers in 40-49 year old women that the benefit of screening is likely to be low. For women aged 50-69, the proportional incidence found in this study was similar to those found in the UK programmes.

Evaluation of breast cancer incidence: is the increase due entirely to mammographic screening?

OBJECTIVES: To examine the trends in the incidence rates of breast cancer in a population with mammographic screening and in the unscreened women within that population. METHODS: Data consisted of incident cases of breast cancer notified to the Victorian Cancer Registry in Victoria, Australia, between 1988 and 1996 and cases detected in the population-based BreastScreen Program. These data were grouped by age (25-39, 40-49, 50-59, 60-69 and > or = 70 years of age) and size of tumor (< or =10 mm, > 10-< or =15 mm, and > 15 mm). Poisson regression modeling was used to examine trends by age, tumor size, calendar year and availability of screening. RESULTS: The incidence rate of breast cancer in the total population increased between 1988 and 1996. The greatest increase was seen after 1993 when population-based screening became available. In unscreened women, modeling demonstrated a statistically significant (p < 0.01) 1.5% annual increase in the incidence rate. The annual increase in this rate differed by size of tumor and was approximately 8% (p < 0.01) for small tumors (< or = 10 mm) but not significant for tumors > 10 mm. The greatest increase was in small tumors for women > or = 50 years of age. CONCLUSION: The incidence of breast cancer has increased since population-based mammographic screening was introduced in 1994. The rate in unscreened women also showed a significant increase. This was greatest in small tumors for women > or = 50 years of age. Whether this will translate into an increase in mortality is uncertain and long-term monitoring is required to determine if cohort and period effects impact on the underlying incidence of breast cancer in Victoria.

Screening endoscopy and risk of colorectal cancer in United States men.

OBJECTIVES: The purpose of this study was to describe the effect of screening endoscopy (sigmoidoscopy or colonoscopy) on colorectal cancer incidence and mortality. METHODS: We used data from a prospective cohort study of 24,744 men aged 40 to 75 years in 1986, free from cancer and colon polyps, followed until 1994. The outcomes are diagnosis of colorectal cancer and death from colorectal cancer. RESULTS: Screening endoscopy in 1986-87 was associated with a lower risk of all colorectal cancer (multivariate relative risk [RR] = 0.58, 95 percent confidence interval [CI] = 0.36-0.96); cancer in the distal colon or rectum (multivariate RR = 0.40, CI = 0.19-0.84); Dukes stage A&B (multivariate RR = 0.66, CI = 0.35-1.25); and Dukes stage C&D (multivariate RR = 0.50, CI = 0.20-1.26) colorectal cancer; and death from colorectal cancer (multivariate RR = 0.56, CI = 0.20-1.60), after adjusting for age and a wide range of colon cancer risk factors. Screening endoscopy in 1988-87 appeared to provide strong protection against distal stage C&D cancers (age-adjusted RR = 0.16, CI = 0.02-1.23) but no protection against proximal stage C&D cancers (age-adjusted RR = 0.96, CI = 0.32-2.91). CONCLUSIONS: This study provides strong evidence for a protective effect of screening sigmoidoscopy on colorectal cancer incidence and mortality and supports recommendations for screening sigmoidoscopy as an approach to colon cancer prevention.