Energy-Related Indicators and Breast Cancer Risk among White and Black Women

Energy-related indicators, including physical activity, energy intake, body mass index (BMI) and adult weight change, have been linked to breast cancer risk. Very few studies of these associations have been conducted among black women, therefore we used the Nashville Breast Health Study (NBHS) to determine whether similar effects were seen in black and white women. The NBHS is a population-based case-control study of breast cancer among women age 25 to 75 years conducted between 2001 and 2010 in and around the Nashville Metropolitan area. Telephone interviews and self-administered food frequency questionnaires were completed with 2,614 incident breast cancer cases ascertained through hospitals and the statewide cancer registry, and 2,306 controls selected using random digit dialing. Among premenopausal white and black women, there was little effect of adult exercise or other energy-related indicators on breast cancer risk, regardless of tumor estrogen receptor (ER) status. The beneficial effect of adult exercise on postmenopausal breast cancer appeared to be comparable between white and black women (highest tertile relative to none - white odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-1.0, p for trend=0.05; black OR 0.7, 95% CI 0.4-1.1, p for trend=0.07); however, among black women the reduction was limited to those with ER-positive disease. White and black women should be encouraged to engage in more physical activity to reduce their risk of postmenopausal breast cancer.     

Depot medroxyprogesterone (Depo-Provera) and risk of breast cancer.

OBJECTIVE--To determine whether use of the injectable contraceptive depot medroxyprogesterone acetate (Depo-Provera) affects the risk of breast cancer in women. DESIGN--A population based case-control study. SETTING--Nationwide community study. SUBJECTS--891 Women aged 25-54 with newly diagnosed breast cancer were compared with 1864 women selected at random from the electoral rolls. INTERVENTION--Women were interviewed by telephone about past use of contraceptives and about possible risk factors for breast cancer. MAIN OUTCOME MEASURE--Relative risk of breast cancer in women who had used medroxyprogesterone. RESULTS--Medroxyprogesterone had been used by 110 patients and 252 controls. Overall, the relative risk of breast cancer associated with any duration of use was 1.0 (95% confidence interval 0.80 to 1.3). In women aged 25-34 the relative risk was 2.0 (1.0 to 3.8). The relative risk was highest in women aged 25-34 who had used the drug for six years or longer, although there were few women in this category. Women who had used it for two years or longer before age 25 had an increased risk of breast cancer (relative risk 4.6; 1.4 to 15.1). CONCLUSION--Despite the lack of an overall association these findings suggest that medroxyprogesterone may increase the risk of breast cancer in young women.     

Selected polymorphisms in sex hormone-related genes, circulating sex hormones and risk of endometrial cancer

Background: The role of estrogen and progesterone in the development of endometrial cancer is well documented. Few studies have examined the association of genetic variants in sex hormone-related genes with endometrial cancer risk. Methods: We conducted a case-control study nested within three cohorts to examine the association of endometrial cancer risk with polymorphisms in hormone-related genes among 391 cases (92% postmenopausal at diagnosis) and 712 individually-matched controls. We also examined the association of these polymorphisms with circulating levels of sex hormones and SHBG in a cross-sectional analysis including 596 healthy postmenopausal women at blood donation (controls from this nested case-control study and from a nested case-control study of breast cancer in one of the three cohorts). Results: Adjusting for endometrial cancer risk factors, the A allele of rs4775936 in CYP19 was significantly associated (OR(per allele)=1.22, 95% CI=1.01-1.47, p(trend)=0.04), while the T allele of rs10046 was marginally associated with increased risk of endometrial cancer (OR(per allele)=1.20, 95% CI=0.99-1.45, p(trend)=0.06). PGR rs1042838 was also marginally associated with risk (OR(per allele)=1.25, 95% CI=0.96-1.61, p(trend)=0.09). No significant association was found for the other polymorphisms, i.e. CYP1B1 rs1800440 and rs1056836, UGT1A1 rs8175347, SHBG rs6259 and ESR1 rs2234693. Rs8175347 was significantly associated with postmenopausal levels of estradiol, free estradiol and estrone and rs6259 with SHBG and estradiol. Conclusion: Our findings support an association between genetic variants in CYP19, and possibly PGR, and risk of endometrial cancer.     

Trends in breast cancer mortality in Trinidad and Tobago—A 35-year study

Background: Breast cancer is the most frequently diagnosed cancer among women worldwide. This study examines the breast cancer mortality patterns and trends in the Caribbean island state, Trinidad and Tobago for the 35-year period, 1970–2004. Methods: A retrospective analysis of the trends in breast cancer mortality from 1970 to 2004 was conducted. Crude mortality per 100,000 women, age-standardized mortality using World Standard population and age-stratified mortality were calculated and comparison was made between age groups above and below 50 years. Results: A general pattern of increase was observed in both crude and age-standardized mortality. The overall average crude mortality was 15.6 per 100,000 women (95% confidence interval (CI) 13.9–17.1) and the average age-standardized mortality was 18.0 per 100,000 women (95% CI 16.7–19.2). There was a pattern of increase in mortality with increasing age. The mortality rate was considerably higher for the age groups above 50 years than those less than 50 years of age both showing an upward trend over the 35-year period. Conclusions: Breast cancer mortality continued to increase over the 35-year period in Trinidad and Tobago. This study did not identify the exact reasons for this increasing trend. However, it is known that Trinidad and Tobago is becoming much more industrialized. It may be speculated that decrease in fertility rates, increase in the incidence of obesity and hormone utilization could have influenced this trend.     

Fracture Risk and Adjuvant Therapies in Young Breast Cancer Patients: A Population-Based Study

Background

Breast cancer survivors have an increased risk of bone fracture. But the risk among young patients with adjuvant therapies remains unknown. This population-based study is aimed to assess the incidence and risk of fracture among young (age of 20 to 39 years) breast cancer patients who received adjuvant therapies.

Methods

From January 2001 to December 2007, 5,146 newly diagnosed breast cancer patients were enrolled from the National Health Insurance Research Database (NHIRD) in Taiwan. Patients were observed for a maximum of 6 years to determine the incidence of newly onset fracture. Kaplan Meier and Cox regression analyses were used to evaluate the risk of fracture in young breast cancer patients who received adjuvant treatments.

Results

Of the total 5,146 young (age of 20 to 39 years) breast cancer patients, the Cox multivariate proportional hazards analysis showed that AIs, radiotherapy, and monoclonal antibodies were significantly associated with a high risk of fracture. Moreover, patients who received AIs for more than 180 days had a high hazard ratio (HR) of 1.77 (95% CI = 0.68–4.57), and patients who received more than four radiotherapy visits had a high HR of 2.54 (95% CI = 1.07–6.06). Under the site-specific analysis, young breast cancer patients who received AIs had the highest risk of hip fracture (HR = 8.520, 95% CI = 1.711–42.432, p < 0.04), whereas patients who received radiotherapy had the highest risk of vertebral fracture (HR = 5.512, 95% CI = 1.847–16.451, p < 0.01).

Conclusion

Young breast cancer patients who are receiving AIs, radiotherapy or monoclonal antibody need to be more careful for preventing fracture events. Breast cancer treatment plans are suggested to incorporate fracture prevention interventions.     

The Effect of Breast‐Feeding with and without Formula Use on the Risk of Obesity at 4 Years of Age

Objective: To determine the minimal duration of breast‐feeding required to protect against later obesity, whether the concurrent use of formula lessened any protective effect of breast‐feeding, and what maternal or child characteristics might modify the association between breast‐feeding and child obesity. Research Methods and Procedures: This was a retrospective cohort study. Participants were 73, 458 white and black low‐income children followed from birth through 4 years of age. Obesity at age 4 years was defined as measured BMI ≥ 95th percentile. Feeding exposure was based on breast‐feeding duration and the age of formula initiation. Covariates were obtained from the children's birth certificates. Results: At age 4 years, the prevalence of obesity was 11.5%. Only 16% of children were breast‐fed 8 weeks or longer. Breast‐feeding was associated with a reduced risk of obesity only in white children whose mothers had not smoked in pregnancy. In this subgroup, the reduction in obesity risk (adjusted odds ratio, 95% confidence interval), compared with those never breast‐fed, occurred only for children who were breast‐fed at least 16 weeks without formula (0.71, 0.56 to 0.92) or at least 26 weeks with concurrent formula (0.70, 0.61 to 0.81). Among whites whose mothers smoked in pregnancy and among blacks, breast‐feeding was not associated with a reduced risk of obesity at age 4 years. Discussion: In a population of low‐income children, breast‐feeding was associated with a reduced risk of obesity at age 4 years only among whites whose mothers did not smoke in pregnancy and only when breast‐feeding continued for at least 16 weeks without formula or at least 26 weeks with formula.     

Anthropometry and body composition of 18 year old men according to duration of breast feeding: birth cohort study from Brazil

Objective To assess the association between duration of breast feeding and measures of adiposity in adolescence.Design Population based birth cohort study.Setting Pelotas, a city of 320 000 inhabitants in a relatively developed area in southern Brazil.Participants All newborn infants in the city''s hospitals were enrolled in 1982; 78.8% (2250) of all male participants were located at age 18 years when enrolling in the national army.Main outcome measures Weight, height, sitting height, subscapular and triceps skinfolds, and body composition (body fat, lean mass).Results Neither the duration of total breast feeding nor that of predominant breast feeding (breast milk plus non-nutritive fluids) showed consistent associations with anthropometric or body composition indices. After adjustment for confounding factors, the only significant associations were a greater than 50% reduction in obesity among participants breast fed for three to five months compared with all other breastfeeding categories (P = 0.007) and a linear decreasing trend in obesity with increasing duration of predominant breast feeding (P = 0.03). Similar significant effects were not observed for other measures of adiposity. Borderline direct associations also occurred between total duration of breast feeding and adult height (P = 0.06).Conclusions The significant reduction in obesity among children breast fed for three to five months is difficult to interpret, as no a priori hypothesis existed regarding a protective effect of intermediate duration of breast feeding. The findings indicate that, in this population, breast feeding has no marked protective effect against adolescent adiposity.     

Exposure to Bovine Leukemia Virus Is Associated with Breast Cancer: A Case-Control Study

Background

Age, reproductive history, hormones, genetics, and lifestyle are known risk factors for breast cancer, but the agents that initiate cellular changes from normal to malignant are not understood. We previously detected bovine leukemia virus (BLV), a common oncogenic virus of cattle, in the breast epithelium of humans. The objective of this study was to determine whether the presence of BLV DNA in human mammary epithelium is associated with breast cancer.

Methods

This was a case-control study of archival formalin fixed paraffin embedded breast tissues from 239 donors, received 2002–2008 from the Cooperative Human Tissue Network. Case definition as breast cancer versus normal (women with no history of breast cancer) was established through medical records and examination of tissues by an anatomical pathologist. Breast exposure to BLV was determined by in situ-PCR detection of a biomarker, BLV DNA, localized within mammary epithelium.

Results

The frequency of BLV DNA in mammary epithelium from women with breast cancer (59%) was significantly higher than in normal controls (29%) (multiply- adjusted odds ratio = 3.07, confidence interval = 1.66–5.69, p = .0004, attributable risk = 37%). In women with premalignant breast changes the frequency of BLV DNA was intermediate (38%) between that of women with breast cancer and normal controls (p for trend < .001).

Conclusions

Among the specimens in this study, the presence of amplified BLV DNA was significantly associated with breast cancer. The odds ratio magnitude was comparable to those of well-established breast cancer risk factors related to reproductive history, hormones, and lifestyle and was exceeded only by risk factors related to genetics (familial breast cancer), high dose ionizing radiation, and age. These findings have the potential for primary and secondary prevention of breast cancer.     

Incidence and duration of lactation and lactational performance among mothers of low-birth-weight and term infants.

The lactation experience of 55 mothers of 62 infants of low birth weight (2500 g or less) was prospectively compared with that of 55 mothers of 55 control infants (38 weeks'' gestation or more, birth weight more than 2500 g) born at the same institution. The incidence rates of lactation at delivery were 73% for the control group and 58% for the low-birth-weight group; 11% of the infants of low birth weight fed breast milk were never put to the breast. The mean age at first suckling was 277.3 hours in the low-birth-weight group, compared with 3.3 hours in the control group (p less than 0.0005). At first suckling 81% of the low-birth-weight infants and 25% of the control infants sucked poorly or refused the breast (p less than 0.001). At discharge 65% of the breast-milk-fed control infants were exclusively breast-fed, compared with 3% of the low-birth-weight infants fed breast milk (p less than 0.001). The incidence rates of lactation over time were similar in the control and low-birth-weight groups (51% v. 44% at 1 month, 29% v. 13% at 3 months, 13% v. 4% at 6 months and 4% v. 2% at 12 months). The mean duration of lactation was 3.2 months for the control group and 2.5 months for the low-birth-weight group. In the long term 37% of the low-birth-weight infants fed breast milk failed to breast-feed, compared with 2% of the control infants, and only 31% were exclusively breast-fed, compared with 85% of the control infants (p less than 0.001). However, the degree of satisfaction with the lactation experience was similar in the two groups. We conclude that mothers of low-birth-weight infants have good potential for lactation.     

Additive Interactions of Maternal Prepregnancy BMI and Breast‐feeding on Childhood Overweight

Objective: To examine the interactions of maternal prepregnancy BMI and breast‐feeding on the risk of overweight among children 2 to 14 years of age. Research Methods and Procedures: The 1996 National Longitudinal Survey of Youth, Child and Young Adult data in the United States were analyzed (n = 2636). The weighted sample represented 51.3% boys, 78.0% whites, 15.0% blacks, and 7.0% Hispanics. Childhood overweight was defined as BMI ≥95th percentile for age and sex. Maternal prepregnancy obesity was determined as BMI ≥30 kg/m². The duration of breast‐feeding was measured as the weeks of age from birth when breast‐feeding ended. Results: After adjusting for potential confounders, children whose mothers were obese before pregnancy were at a greater risk of becoming overweight [adjusted odds ratio (OR), 4.1; 95% confidence interval (CI), 2.6, 6.4] than children whose mothers had normal BMI (<25 kg/m²; p < 0.001 for linear trend). Breast‐feeding for ≥4 months was associated with a lower risk of childhood overweight (OR, 0.6; 95% CI, 0.4, 1.0; p = 0.06 for linear trend). The additive interaction between maternal prepregnancy obesity and lack of breast‐feeding was detected (p < 0.05), such that children whose mothers were obese and who were never breast‐fed had the greatest risk of becoming overweight (OR, 6.1; 95% CI, 2.9, 13.1). Discussion: The combination of maternal prepregnancy obesity and lack of breast‐feeding may be associated with a greater risk of childhood overweight. Special attention may be needed for children with obese mothers and lack of breast‐feeding in developing childhood obesity intervention programs.     

Expression of p27Kip1 and bcl-2, cigarette smoking,and colorectal cancer risk

Although a positive association between cigarette smoking and colorectal adenoma development is consistently found, the association with colorectal cancer remains controversial. We evaluated the potential roles of p27^Kip1 and bcl-2 protein expressions in conjunction with cigarette smoking exposure and colorectal cancer risk in a hospital-based case-control study. A total of 163 colorectal cancer patients from Roswell Park Cancer Institute and Buffalo General Hospital and 326 healthy controls responded to a standardized questionnaire on colorectal cancer risk factors including detailed information on their history of cigarette smoking; 110 of the patients' tumours were available for immunohistochemical analysis of p27^Kip1 and bcl-2 protein overexpression. An avidin-biotin immunoperoxidase procedure was used to determine expression after incubation with mouse monoclonal p27^Kip1 and mouse monoclonal bcl-2 antibodies, respectively. A statistically significant trend for total pack-years of smoking was found when p27^Kip1 positive cases were compared with p27^Kip1 negative cases (trend test, p = 0.007). Although a weak inverse association was observed with smoking exposure among p27^Kip1 negative tumour cases in comparison to controls, a significant dose-response association was seen with p27^Kip1 positive tumours. The relative risk of developing a p27^Kip1 positive tumour was estimated to be 1.17 (95% CI 0.54-2.54) for those with less than 20 pack-years, 1.95 (95 % CI 0.95-3.97) for those with 20-39 pack-years, and 2.25 (95% CI 1.14-4.45) for those with greater than 39 pack-years of smoking exposure (trend test, p = 0.009) when compared with controls. When cases with bcl-2 expression were compared with cases without bcl-2 expression, suggestion of a trend was also observed with pack-years smoked (trend test, p = 0.09). In our study of 110 patients with sporadic colorectal cancer and 326 controls, we observed differences in associations between cigarette smoking and expressions in p27^Kip1 and bcl-2. Our data suggest that bcl-2 overexpression (or a bcl-2 dependent pathway) is associated with cigarette smoking in the development of colorectal cancer, whereas a loss of p27^Kip1 expression is not. These associations indicate that there is aetiological heterogeneity in colorectal cancer development, and that they can indirectly allude to where these changes in protein expression occur in the adenoma-carcinoma sequence (i.e. early versus late events).     

Behavioral Energetics of Lactation in a Herbivorous Carnivore,the Red Panda (Ailurus fulgens)

In most mammals, the energetic costs of lactation significantly increase a female's daily energy requirements. Previous research indicates that such energetic costs may be met through changes in increased food consumption ranging from around 35 % to 150 %. In this paper, changes in food intake during lactation are measured in the red panda (Ailurus fulgens), a species of the order Carnivora which possesses a digestive system suited for a carnivorous diet but yet exclusively feeds on bamboo. Four feeding characteristics were studied: duration of feeding bouts, number of bamboo leaves consumed per mouthful, number of bamboo leaves consumed per minute, and interval between mouthfuls of bamboo. In three lactating females, three of four feeding behaviors significantly increased up to 200 % above the rate observed during non-lactation. Males showed no change in feeding behavior during the same reproductive months with identical available foods. Red pandas appear to suffer a more severe energetic cost during lactation (at least with respect to food consumption) than other mammals previously studied. This may relate to their inefficient digestive capacity to process a herbivorous diet of bamboo. The data presented here suggest that general discussions of the relative costs of reproduction and in turn parental investment should include a female's relative digestive efficiency during stressful reproductive periods.     

Expression of p27Kip1 and bcl-2, cigarette smoking, and colorectal cancer risk

Although a positive association between cigarette smoking and colorectal adenoma development is consistently found, the association with colorectal cancer remains controversial. We evaluated the potential roles of p27^Kip1 and bcl-2 protein expressions in conjunction with cigarette smoking exposure and colorectal cancer risk in a hospital-based case-control study. A total of 163 colorectal cancer patients from Roswell Park Cancer Institute and Buffalo General Hospital and 326 healthy controls responded to a standardized questionnaire on colorectal cancer risk factors including detailed information on their history of cigarette smoking; 110 of the patientsfitumours were available for immunohistochemical analysis of p27^Kip1 and bcl-2 protein overexpression. An avidin?biotin immunoperoxidase procedure was used to determine expression after incubation with mouse monoclonal p27^Kip1 and mouse monoclonal bcl-2 antibodies, respectively. A statistically significant trend for total pack-years of smoking was found when p27^Kip1 positive cases were compared with p27^Kip1 negative cases (trend test, p = 0.007). Although a weak inverse association was observed with smoking exposure among p27^Kip1 negative tumour cases in comparison to controls, a significant dose?response association was seen with p27^Kip1 positive tumours. The relative risk of developing a p27^Kip1 positive tumour was estimated to be 1.17 (95% CI 0.54?2.54) for those with less than 20 pack-years, 1.95 (95 % CI 0.95?3.97) for those with 20?39 pack-years, and 2.25 (95% CI 1.14?4.45) for those with greater than 39 pack-years of smoking exposure (trend test, p = 0.009) when compared with controls. When cases with bcl-2 expression were compared with cases without bcl-2 expression, suggestion of a trend was also observed with pack-years smoked (trend test, p = 0.09). In our study of 110 patients with sporadic colorectal cancer and 326 controls, we observed differences in associations between cigarette smoking and expressions in p27^Kip1 and bcl-2. Our data suggest that bcl-2 overexpression (or a bcl-2 dependent pathway) is associated with cigarette smoking in the development of colorectal cancer, whereas a loss of p27^Kip1 expression is not. These associations indicate that there is aetiological heterogeneity in colorectal cancer development, and that they can indirectly allude to where these changes in protein expression occur in the adenoma?carcinoma sequence (i.e. early versus late events).     

Reproductive factors and breast cancer risk in Palestine: A case control study

BackgroundEarly age at menarche, late age at menopause, and late age at first full-term pregnancy are linked to a modest increase in the risk of developing breast cancer (breast ca). This study aims to investigate the reproductive determinants of breast cancer among women in the West Bank of Palestine.A structured questionnaire was used to collect data in a case-control study (237 registered cases and 237 controls). A multivariate analysis model was used to adjust for the association between women’s reproductive factors and breast ca risk. This study was approved by Al Quds University Ethical Research Committee and the Ministry of Health research unit.ResultsIn the multivariate analysis, menarche after 13 years of age, use of oral contraceptives for more than two months, and hormonal contraceptives use significantly doubled the risk for breast ca (Adjusted Odds Ratio (AOR) = 2.03, 95 % CI: 1.21–4.37, p < 0.011 and AOR = 2.2, 95 % CI: 1.24–4.01, p = 0.008, respectively). Women who used hormone replacement therapy (HRT) were significantly associated with higher odds (5 folds) of having breast ca versus those who did not use them (AOR 5.02, 95 % CI: 1.93–13.06, p = 0.001). Similarly, nulliparous women showed 6 times the odds of breast ca compared with women with one or more children (p = 0.005). Also, parental consanguinity marriage (AOR 2.59, 95 % CI: 1.53–4.36, p = 0.001) and positive family history (AOR 3.88, 95 % CI: 2.19–6.87, p = 0.001) of the condition can be strong determinants for breast ca in this study.ConclusionThis study provides clear evidence that the use of reproductive hormones, whether as a birth control tool or for therapeutic purposes, must be rationalized worldwide and in Palestine in particular.     

Short term increase in risk of breast cancer after full term pregnancy.

To determine whether there is a short term increase in the risk of breast cancer after a full term birth data from two hospital based, case-control studies in Italy were pooled. Analysis was restricted to women aged under 50 with two or more children (573 women with cancer and 570 controls). A relative risk for breast cancer of 2.66 was seen in women who had given birth during the three years preceding the interview compared with women whose last birth had occurred 10 or more years before, after adjustment for age, age at first birth, and parity. The relative risk slowly decreased for women who had last given birth three to 10 years before. Multivariate analyses confirmed the protective effect of an early age at first birth and the age dependent effect of parity on the risk of breast cancer--that is, a direct relation below age 40 and an inverse one in older women. These data provide epidemiological evidence that a full term birth is followed by a transient increase in the risk of breast cancer, which for some time contrasts with and overcomes the long term protection of pregnancy at an early age. They therefore confirm predictions from animal studies and theoretical models that pregnancy prevents the early stages of breast carcinogenesis but promotes the late stages of the process.     

Aetiology of testicular cancer: association with congenital abnormalities,age at puberty,infertility, and exercise. United Kingdom Testicular Cancer Study Group.

OBJECTIVE--To determine the risk of testicular cancer associated with undescended testis, inguinal hernia, age at puberty, marital status, infertility, vasectomy, and amount of exercise. DESIGN--A population based case-control study with a questionnaire administered by an interviewer and with relevant supplementary data extracted from general practitioners'' notes. SETTING--Nine health regions within England and Wales. SUBJECTS--794 men, aged 15-49 years, with a testicular germ cell tumour diagnosed between 1 January 1984 and 1 January 1987; each had an age matched (within one year) control selected from the list of their general practitioner. RESULTS--There was a significant association of testicular cancer with undescended testis (odds ratio 3.82; 95% confidence interval 2.24 to 6.52) and inguinal hernia (1.91; 1.12 to 3.23). The excess risk associated with undescended testis was eliminated in men who had had an orchidopexy before the age of 10 years. There were positive associations with early age at voice breaking, early age at starting to shave, and infertility. There was a significant association with a sedentary lifestyle and a moderate protective effect of exercise. There was no association with vasectomy. CONCLUSION--This study confirms previous reports that developmental urogenital abnormalities result in an increased risk of testicular cancer. The trend to perform orchidopexy at younger ages may reduce the risk associated with undescended testis. The increased risks associated with early age at puberty and low amounts of exercise may be related to effects of exposure to endogenous hormones. Changes in both of these factors may partly contribute to the increasing rates of testicular cancer observed in the past few decades.     

Impact of breast feeding on admission for pneumonia during postneonatal period in Brazil: nested case-control study

ObjectiveTo determine whether breast feeding protects infants against pneumonia and whether the protection varies with age.DesignNested case-control study.SettingPelotas, southern Brazil.SubjectsCases were 152 infants aged 28-364 days who had been admitted to hospital for pneumonia. Controls were 2391 cases in a population based case-control study.ResultsInfants who were not being breast fed were 17 times more likely than those being breast fed without formula milk to be admitted to hospital for pneumonia (95% confidence interval 7.7 to 36.0). This relative risk was 61 (19.0 to 195.5) for children under 3 months old, decreasing to 10 (2.8 to 36.2) thereafter. Supplementation with solids was associated with a relative risk of 13.4 (7.6 to 23.5) for all infants and 175 (21.8 to 1405.1) for those under 3 months old.ConclusionBreast feeding protects young children against pneumonia, especially in the first months of life. These results may be used for targeting intervention campaigns at the most vulnerable age groups.

Key messages

• Pneumonia is the leading cause of death in children under 5 years old across the world
• In Brazil infants who were not breast fed were 17 times more likely than those receiving breast milk alone to be admitted for pneumonia
• The relative risk of admission was 61 for children under 3 months of age, decreasing to 10 thereafter
• Supplementation with solids was associated with a relative risk of 13.4 for all infants
• Mothers must be encouraged to breast feed very young infants and be advised of the right time to introduce supplementary foods

     

Age as a factor in breast cancer knowledge,attitudes and screening behaviour.

OBJECTIVE: To determine whether there are age-related differences in knowledge, attitudes and behaviour with respect to breast cancer and whether the differences reflect the age-specific Canadian recommendations on breast cancer screening. DESIGN: Telephone survey. SETTING: Two cities and five towns and their surrounding areas in Alberta. PARTICIPANTS: The age-specific, randomly selected sample comprised 1284 women aged 40 to 75 years who did not have breast cancer. Of the 1741 eligible women who were contacted, 1350 (78%) agreed to participate; 66 were excluded because of age ineligibility or a history of breast cancer. MAIN OUTCOME MEASURE: Frequency of knowledge, attitudes and behaviour with respect to breast cancer, by age group. RESULTS: Knowledge of breast cancer risk factors was generally low and decreased with age. Few women were aware of the Canadian recommendations on breast self-examination, physical examination of the breasts by a health care practitioner and mammographic screening. Older women believed they were less susceptible to breast cancer than younger women and were less likely to have positive attitudes toward screening. Self-examination was performed 9 to 15 times per year by 424 women (33%), and 810 (63%) had been examined by a health care professional in the past year. Although 664 (52%) had undergone mammography, the proportion decreased with age after age 59. The main barriers to mammography were lack of physician referral and the woman''s belief that the procedure is unnecessary if she is healthy. CONCLUSIONS: Education is needed to increase breast cancer knowledge, promote the Canadian recommendations for early detection of breast cancer and decrease negative beliefs about the disease. Changes in the behaviour of women and physicians are needed to increase the use of breast self-examination, clinical breast examination by a health care professional and mammographic screening. Reaching women in the upper range (60 to 69 years) of the target group for mammographic screening should be a focus in promoting early detection of breast cancer.     

Immunohistochemical expression of p53 in breast carcinoma is associated with the intron 1 BglII polymorphism of the p53 gene

Breast carcinoma is a public health problem worldwide. It is known that both genetic and environmental factors are important for breast carcinogenesis and that structural and/or functional alterations at p53 gene are commonly observed in breast tumors. In addition, polymorphisms of several genes in either their coding or non-coding sequences have been found related to cancer risk and/or clinicopathological characteristics of tumors. In this study we have evaluated the intron 1 BglII polymorphism of the p53 gene with a PCR-based approach in 117 cases of breast cancer and 102 healthy women and its association with the immunohistochemical expression of p53 in the tumors. The results showed that the presence of the polymorphism (allele 2) is highly associated with the tumor expression of p53 (p<0.0001) and that there is a trend for increased frequency of allele 2 in cases than in controls (p=0.2376). These data suggest that the germ-line variation in the intron 1 of the p53 gene could produce functional or structural changes of the protein that is reflected by its abnormal expression.     

Genetic variation in tumor necrosis factor and lymphotoxin-alpha (TNF–LTA) and breast cancer risk

Tumor necrosis factor (TNF) is critical to regulation of inflammation. Genetic variation in the promoter region of TNF has been associated with expression differences, and a range of auto-immune, infectious, and oncologic diseases. We analyzed eight common single nucleotide polymorphisms (SNPs) (rs746868, rs909253, rs1799964, rs1800630, rs1800750, rs1800629, rs361525, and rs1800610) to capture most of the genetic variation in TNF in addition to SNPs in lymphotoxin-alpha (LTA), a pro-inflammatory cytokine in linkage disequilibrium with the TNF promoter region. SNPs were genotyped in a USA population-based case-control study (3,318 cases, 2,841 controls). Promising results were followed-up in an independent population-based case-control study in Poland (2,228 cases, 2,378 controls). In both studies, women carrying the variant allele of rs361525 were at elevated breast cancer risk compared to the GG genotype (per allele OR = 1.18, 95% CI 1.04–1.35; P for trend = 0.008). Other SNPs were not significantly associated with breast cancer risk. Haplotype analyses did not reveal any additional associations between TNF and breast cancer risk. Data from 5,269 cases and 4,982 controls suggested that the rs361525 A allele, located in the TNF promoter region, was associated with a modest increase in breast cancer risk. Additional studies are required to replicate these findings and to determine whether rs361525 is a causative SNP or is a marker of a causative SNP.