Is the incidence of breast cancer declining?

It has been suggested that the incidence of breast cancer has been declining since the year 2000. This apparent trend may be at least partially explained by a decline in the prevalence of undiagnosed precancerous and early cancerous lesions in the breast, resulting from screening.     

Does vitamin d deficiency account for ethnic differences in tuberculosis seasonality in the UK?

Objectives. Notifications of tuberculosis in England and Wales are reported to peak in the summer season. The purpose of this study was to confirm that finding and to determine to what extent patients of Indian Subcontinent (ISC) ethnic origin contributed to the seasonality. The clinical presentation of the disease is presumed to occur some months following reactivation of the endogenous latent focus of tuberculosis infection. There arises the possibility of vitamin D deficiency producing immunological inadequacy at the end of winter and beginning of spring.

Patients and methods. Monthly (or 4‐weekly) aggregated data over 7 years were collected from the three countries of mainland Britain, England, Wales, Scotland and from the city of Birmingham in England. The notifications from Birmingham were divided into those of ISC ethnic origin and ‘whites’. The presence or absence of seasonality was determined by fitting a sinusoidal curve by the technique called ‘cosinor analysis’. In this method amplitude gives a measure of the extent of the seasonal variation.

Results. The summer peak of clinical diagnosis was confirmed in the UK series from England, Wales and Scotland. In England and Wales without Scotland a larger seasonal variation was present. Scotland, with a lower proportion of population of ISC ethnic origin, was examined separately and the results in Scotland alone failed to confirm seasonality. In the data from Birmingham, seasonality was confirmed with a greater amplitude, particularly in those over 60 years of age. The finding was influenced by those of ISC ethnic origin, seasonality not being present in the ‘white’ population.

Conclusion. The results from Birmingham are very striking, but there were almost three times as many patients in the ISC ethnic group as in indigenous ‘white’ patients. A series with larger numbers of ‘white’ patients would be necessary to confirm the absence of seasonality in the ‘white’ population. The discussion reviews the evidence that vitamin D may have an important hormonal role in immunological defence in the prevention of tuberculosis.     

Can ethnic differences in men's preferences for women's body shapes contribute to ethnic differences in female adiposity?

In the United States, obesity is more common among black and Hispanic than white women. One putative cause of this difference is different cultural norms for attractiveness. Two studies assessed ethnic differences in men's perceptions of the attractiveness of females of varying sizes. In the first, 108 men recruited on the New York subway were shown sets of silhouettes depicting female bodies varying in fatness and were asked to pick the silhouette they found most attractive. They were also asked to indicate the thinnest and fattest figures they would consider dating. A measure of "latitude of acceptance" was computed as the difference between the thinnest and fattest figures considered. Results indicated no relationship between ethnicity and preference (F = 1.383, p = .257) or "latitude" (F = .102, p = .903). In Study 2, "personal advertisements" placed by 373 black, 1915 white, 110 Hispanic, and 30 Asian men from 35 newspapers and magazines were coded as: 1) thinness preferred; 2) no information on weight preference; 3) fatness preferred; or 4) states weight or looks unimportant. Results indicated a statistically significant but small association between ethnicity and preference (chi2 = 49.55, df = 9, p < .00001). Relative to white and Asian men, black and Hispanic men more frequently requested fat women, Hispanic men less frequently requested thin women, and black men more frequently stated that looks or weight did not matter. Ethnicity explained only 2.1% of the variance in preference. Thus, it seems unlikely that ethnic differences in men's preferences for women's body shapes contribute substantially to ethnic differences in female adiposity.     

Does breast cancer change patients' dietary habits?

PURPOSE: The results of epidemiological studies on diet and cancer are often difficult to interpret on an individual level and may influence patients' beliefs, attitudes and behaviour. This study investigated the behaviour of breast cancer patients and their attitudes to dietary changes and the need of dietary advice during their disease. PATIENTS AND METHODS: The study population consisted of breast cancer patients visiting the Department of Oncology in Turku University Hospital for treatment or follow-up in August and September 1999. A questionnaire was given to a total of 123 subjects. RESULTS: The majority, 65%, were attending the clinic for treatment, 35% for follow-up. Ninety-seven patients (86%) consumed a normal Finnish diet, six (5.3%) were vegetarians and 10 (8.1%) vegetarians consuming fish and chicken occasionally. Eleven patients (8.9%) considered diet a factor contributing to their breast cancer and 38 (31.9%) had changed their dietary habits after the diagnosis of breast cancer. The numbers were higher in younger patients with higher educational background. The main reason for change in diet was the desire to be cured of cancer (52.9% of those patients who had changed their dietary habits), in 11.8% to alleviate the symptoms of nausea and 11.8% were advised by health care professionals. The main changes reported included a reduction in the consumption of animal fat, sugar and red meat and increased consumption of fruit, berries and vegetables. Forty-nine patients (39.8%) used vitamin and mineral supplements and 27 (21.9%) consumed dietary supplements including natural products and probiotics. The source of information on how to change the diet was for 33.3% the mass media, 19.4% were advised by doctors and nurses and 11.1% by dietitians. One-third of the patients expressed a need for more information on dietary factors. CONCLUSION: Breast cancer patients' need of control over their own life prompts an interest in alternative dietary habits after diagnosis, the focus being on a healthier diet. Expert dietary information is considered important. Many patients mentioned a lack of precise dietary recommendations for their individual disease situation and depended on information from outside their treatment centre.     

Does occupation explain gender and other differences in work-related eye injury hospitalization rates?

OBJECTIVE: We sought to determine whether demographic differences in eye injury rates persist after adjusting for occupational exposure. METHODS: On-duty eye injury hospitalizations were linked to occupation among active-duty US Army personnel. RESULTS: Eye injury rates were higher for white soldiers, men, and for younger soldiers, even after adjusting for occupational group and specific job titles using multivariate models. CONCLUSIONS: This finding contrasts with studies of other injuries, suggesting that occupation does not fully account for variations in eye injury risk. Because protective eye-wear can prevent most serious eye injuries, we hypothesize that differences in protective eye-wear use between men and women may contribute to differences in eye injury rates, although follow-up studies are needed to confirm this. Prevention efforts should consider targeting high-risk demographic groups in addition to high-risk occupations.     

Differences in breast cancer screening rates: an issue of ethnicity or socioeconomics?

Previous reports suggest that use of preventive measures, such as screening mammography (SM), differs by ethnicity. It is unclear, however, if this is determined directly by ethnicity or indirectly by related socioeconomic factors. We studied self-reported data from 18,245 women aged 40-49 who participated in the Behavioral Risk Factor Surveillance System telephone survey in 1992 and 1993. Of these, 11,509 (63%) reported having obtained mammography within the preceding 2 years for screening purposes only. Using reports of other preventive healthcare behaviors, education level, socioeconomic status, and healthcare access problems as independent variables, bivariate associations were assessed, and a logistic regression model was developed. Models for each ethnic group were developed, with consistent results. Women who engaged in other preventive health measures, such as Pap smear (odds ratio [OR] 8.99, 95% confidence interval [CI] = 7.6-10.7), cholesterol measurement (OR 2.64, 95% CI = 2.3-3.0), and seatbelt use, were more likely to obtain SM. Women with healthcare access or insurance problems (OR 0. 59, 95% CI = 0.5-0.7) and current smokers (OR 0.71, CI = 0.6-0.8) had a lower likelihood of obtaining SM. Ethnicity, alcohol use, marital status, and education level were not significantly associated with women's reports of SM. Although ethnicity apparently does not influence a woman's likelihood of obtaining SM, access to healthcare and insurance and engaging in other healthy behaviors do. Health policy planners should consider the importance of these related factors when developing preventive health programs for women.     

Is ethnic density associated with risk of child pedestrian injury? A comparison of inter-census changes in ethnic populations and injury rates

Objectives. Research on inequalities in child pedestrian injury risk has identified some puzzling trends: although, in general, living in more affluent areas protects children from injury, this is not true for those in some minority ethnic groups. This study aimed to identify whether ‘group density’ effects are associated with injury risk, and whether taking these into account alters the relationship between area deprivation and injury risk. ‘Group density’ effects exist when ethnic minorities living in an area with a higher proportion of people from a similar ethnic group enjoy better health than those who live in areas with a lower proportion, even though areas with dense minority ethnic populations can be relatively more materially disadvantaged.

Design. This study utilised variation in minority ethnic densities in London between two census periods to identify any associations between group density and injury risk. Using police data on road traffic injury and population census data from 2001 to 2011, the numbers of ‘White,’ ‘Asian’ and ‘Black’ child pedestrian injuries in an area were modelled as a function of the percentage of the population in that area that are ‘White,’ ‘Asian’ and ‘Black,’ controlling for socio-economic disadvantage and characteristics of the road environment.

Results. There was strong evidence (p < 0.001) of a negative association between ‘Black’ population density and ‘Black’ child pedestrian injury risk [incidence (of injury) rate ratios (IRR) 0.575, 95% CI 0.515–0.642]. There was weak evidence (p = 0.083) of a negative association between ‘Asian’ density and ‘Asian’ child pedestrian injury risk (IRR 0.901, 95% CI 0.801–1.014) and no evidence (p = 0.412) of an association between ‘White’ density and ‘White’ child pedestrian injury risk (IRR 1.075, 95% CI 0.904–1.279). When group density effects are taken into account, area deprivation is associated with injury risk of all ethnic groups.

Conclusions. Group density appears to protect ‘Black’ children living in London against pedestrian injury risk. These findings suggest that future research should focus on structural properties of societies to explain the relationships between minority ethnicity and risk.     

Mammographic breast density and risk of breast cancer: Masking bias or causality?

Masking bias is hypothesized to explain associations between breast density and breast cancer risk. Tumours in dense breasts may be concealed at the initial examination, but manifest themselves in later years, suggesting an increase in breast cancer incidence. We studied the association between breast density and breast cancer risk in 0, 1–2, 3–4 and 5–6 year periods between initial examination and diagnosis. We studied 359 cases and 922 referents, identified in a breast cancer screening programme in Nijmegen, the Netherlands. Breast density was assessed at the initial examination and classified as 'dense' (if > 25% of the breast was composed of density) or 'lucent' ( 25% density). In women examined with mid-1970s film screen mammography, we found that at time 0 the odds ratio (OR) for women with dense breasts compared to those with lucent breasts was 1.4 (95% confidence interval (CI): 0.7–6.2). After a 3–4 year period the risk was increased to 3.3 (95% CI: 1.5–7.1). Then, the risk decreased again (OR: 1.2, 95% CI: 0.6–2.7). This rise and decline in risk are in accordance with the masking hypothesis. The observation, however, that the risk at time 0 does not appear to be lower for women with dense breasts than for those with lucent breasts, seems to be inconsistent with the masking hypothesis and may be indicative of causality. The same analysis were performed in women whose initial screening examination was done with current high-quality mammography. Due to the small size of this study group no firm conclusions could be drawn, but it seems as if masking bias could still play a role with high-quality mammography.     

Estimating breast cancer incidence in Hispanic women in Connecticut, 1989–1991

Objectives. The objective of this study was to estimate incidence rates for breast cancer, the most commonly occurring cancer in women, in the growing Hispanic population of Connecticut.

Methods. The population‐based Connecticut Tumor Registry (CTR) routinely obtains only limited information on Hispanic origin and maiden name. In this study, surnames of CTR breast cancer patients diagnosed in 1989–1991 were matched with a list of Spanish surnames. To assess misclassification, both surnames and maiden names (from death certificates) of female Connecticut residents who had died in 1989–1991 from any cause of death at 20 years of age and older were matched with the Spanish‐surname list.

Results. Age‐specific incidence rates (1989–1991) for ‘Hispanic’ women (with Spanish surname) were lower than those for ‘non‐Hispanic’ white women (with non‐Spanish surname) for age 35–39 years and older. Errors in these estimated rates were probably small because among decedents the number with a Spanish surname differed by only 9% from the number with a Spanish maiden name; false positives were almost balanced by false negatives.

Conclusion. Matching of surnames in the cancer registry with a Spanish surname list provided reasonably accurate estimates of cancer incidence rates in Hispanic women, although individual women were misclassified as ‘Hispanic’ or ‘non‐Hispanic’.     

Does geography explain ethnic inequalities in health in New Zealand?

OBJECTIVE: To quantify the potential contribution of inter-district relative to intradistrict variation to the Maori disparity in life expectancy in 2000-02, by counterfactual modelling. SETTING, DATA SOURCES AND METHODS: The setting was New Zealand's 21 health districts (District Health Boards, DHBs). All data (population estimates and life expectancy estimates) were sourced from Statistics New Zealand and relate to the 2000-02 period. Maori life expectancy (nationally) was recalculated under the counterfactual that Maori life expectancy in each DHB did not differ from total population life expectancy in the corresponding DHB (so eliminating intra-district variation). The difference between the observed total population and counterfactual Maori life expectancies therefore represents the contribution of inter-district variation to the Maori life expectancy disparity. RESULTS: Observed total population and Maori life expectancies at birth in 2000-02, pooling sexes, were 78.7 and 71.1 years respectively, giving a total disparity of 7.6 years. Under the counterfactual, Maori life expectancy increased to 78.4 years (and total population life expectancy to 79.0 years). Inter-district variation was therefore estimated to potentially contribute only 0.6 years or 8% to the total Maori disparity. Allowing for imprecision, inter-district variation almost certainly accounts for less than 10.5% of the total disparity. CONCLUSION: Inter-district or geographic variation makes only a small contribution to the total Maori disparity in life expectancy. Adjustment or standardisation for district is not necessary when comparing Maori and non-Maori health outcomes. If the policy goal is to reduce ethnic inequalities in health, then the focus of policy (e.g. funding formulae) needs to be on factors directly linked to ethnicity, rather than on geographic variations in health and health care that have an impact on all ethnic groups more-or-less alike.     

Ethnic differences in breast cancer risk: a possible role for pregnancy levels of alpha-fetoprotein?

BACKGROUND: Breast cancer incidence rates are up to five times higher in white women in the United States compared with Asian women in China and Japan. A search for factors that modify estrogen's biological effect differentially between ethnic groups may add to the understanding of international variations in breast cancer risk. Recent evidence indicates that alpha-fetoprotein, a glycoprotein produced by the fetal liver, has important antiestrogenic properties. During pregnancy, alpha-fetoprotein reaches peak concentrations in maternal serum during the third trimester. METHODS: We compared pregnancy levels of alpha-fetoprotein in a population with high risk of breast cancer (Boston, MA) and low risk (Shanghai, China). Blood samples were collected around the 16th week and around the 27th week of gestation among women enrolled from March 1994 to October 1995. The number of specimens available for alpha-fetoprotein analysis was 1,033. RESULTS: Alpha-fetoprotein levels, adjusted for gestational length, were substantially higher in Shanghai compared with Boston women at both time points. When adjustments were made for prepregnancy weight, parity, offspring's sex and maternal age, alpha-fetoprotein levels remained 13% higher in Shanghai at 16 weeks of pregnancy but not at 27 weeks. CONCLUSIONS: These findings may explain, at least in part, the difference in breast cancer risk between Chinese and American women. On the population level, alpha-fetoprotein may influence risk by modifying the effect of biologically active estrogens both in the mother and in female offspring.     

Do rat strain differences in ethanol consumption reflect differences in ethanol sensitivity or the preparedness to learn?

Three strains of rats (Wistar, Sprague-Dawley, Long-Evans; n = 10/strain) were trained to drink various concentrations of ethanol (ETOH) in the rats' home cage in daily 30-min drinking sessions using a modified “Samson” sucrose-fading procedure. Wistar and Sprague-Dawley rats were similar in their voluntary intake of a wide range of ETOH concentrations and both of these strains drank considerably more ETOH than the Long-Evans strain. For comparison purposes only, pharmacological pretreatment tests were later conducted with the Sprague-Dawley strain of rats using a maintenance concentration of 20% w/v ETOH. Low-dose ETOH pretreatments increased (125% of control), and high-dose ETOH pretreatments decreased the subsequent voluntary consumption of ETOH. Low-dose nicotine pretreatments increased ETOH consumption to 148% of control intake, and high doses of nicotine decreased ETOH consumption. Both opiate antagonists, naloxone and naltrexone, produced dose-dependent decreases in ETOH consumption. The dopamine antagonist, haloperidol, produced dose- and time-dependent increases in voluntary ETOH consumption. The strain differences in voluntary ETOH consumption described in the present study differ from those previously described by other labs. We suggest that this strain-dependent disparity between laboratories, with respect to ETOH consumption/preference tasks, may reflect genetic differences in the preparedness to condition (learn) voluntary ETOH consumption rather than genetic differences in ETOH's reward/reinforcement attributes.     

Does hospital discharge policy influence sick-leave patterns in the case of female breast cancer?

The objective was to investigate how differences among hospitals in the shift from in-patient care to day surgery and a reduced hospital length of stay affect the sick-leave period for female patients surgically treated for breast cancer. All women aged 18-64 who were diagnosed with breast cancer in 2000 were selected from the National Cancer Register and combined with data from the sick-leave database of the National Social Insurance Board and the National Hospital Discharge Register (N = 1834). A multi-factorial model was fitted to the data to investigate how differences in hospital care practice affected the length of sick-leave. The main output measure was the number of sick-leave days after discharge during the year following surgery. The confounders used included age, type of primary surgical treatment, whether or not lymph node dissection was performed, labour-market status, county, and readmission. Women treated with breast-conserving surgery had a 54.7-day (-71.9 < or = CI(95%) < or = -37.5) shorter sick-leave period than those with more invasive surgery. The day-surgery cases had 24.3 (-47.5 < or = CI(95%) < or = -1.1) days shorter sick-leave than those who received overnight care. The effect of the hospital median length of stay (LOS) was U-shaped, suggesting that hospitals with a median LOS that is either short or long are associated with longer sick-leave. In the intermediate range, women treated in hospitals with a median LOS of 2 days had 22 days longer sick-leave than those treated in hospitals with a mean LOS of 3 days. This is possibly a sign of sub-optimising.     

Do sex and ethnic differences in smoking initiation mask similarities in cessation behavior?

OBJECTIVES: This study compared success in smoking cessation by sex, ethnic status, and birth cohort. METHODS: African and European American respondents to the 1996 Current Population Survey (tobacco supplement) and the 1987 National Health Interview Survey (cancer control and cancer epidemiology supplements) constituted the study population. Elapsed time from smoking initiation to cessation was compared via nonparametric tests and survival analysis techniques. RESULTS: Findings showed that success in quitting was independent of ethnic status and sex and that population differences in smoking initiation age (assuming no differences in quitting behavior) could produce statistical associations between sex/ethnicity and smoking cessation. CONCLUSIONS: Population differences in smoking initiation patterns can mask similarities in cessation rates.