Obesity and breast disease. The role of the female sex hormones

Correlations between salivary- and blood-derived gonadal hormone assessments and implications for inclusion of female participants in research studies

Even in the 21st century, female participants continue to be underrepresented in human physiology research. This underrepresentation is attributable in part to the perception that the inclusion of females is more time consuming, less convenient, and more expensive relative to males because of the need to account for the menstrual cycle in cardiovascular study designs. Accounting for menstrual cycle-induced fluctuations in gonadal hormones is important, given established roles in governing vascular function and evidence that failure to consider gonadal hormone fluctuations can result in misinterpretations of biomarkers of cardiovascular disease. Thus, for cardiovascular researchers, the inclusion of females in research studies implies a necessity to predict, quantify, and/or track indexes of menstrual cycle-induced changes in hormones. It is here that methodologies are lacking. Gold standard measurement requires venous blood samples, but this technique is invasive and can become both expensive and technically preclusive when serial measurements are required. To this end, saliva-derived measures of gonadal hormones provide a means of simple, noninvasive hormone tracking. To investigate the feasibility of this technique as a means of facilitating research designs that take the menstrual cycle into account, the purpose of this review was to examine literature comparing salivary and blood concentrations of the primary gonadal hormones that fluctuate across the menstrual cycle: estradiol and progesterone. The data indicate that there appear to be valid and promising applications of salivary gonadal hormone monitoring, which may aid in the inclusion of female participants in cardiovascular research studies.

Association between Body Mass Index and Prevalence of Asthma in Korean Adults

We evaluated the association between body mass index (BMI) and the prevalence of asthma. Using data from the 2015 Korean Community Health Survey, 214,971 participants aged between 19 and 106 years were included in this study. Asthma was defined based on the self-report of physician diagnosis. BMI was classified as underweight (<18.5 kg/m²), normal weight (18.5 kg/m²≤BMI<23.0 kg/m²), overweight (23.0 kg/m²≤ BMI<27.4 kg/m²), and obese (≥27.5 kg/m²) based on the BMI categories for Asians by the World Health Organization. Multiple logistic regression analysis was performed with sampling weights to evaluate the association between BMI and asthma after adjusting for age, educational level, income, type of residential area, smoking status, alcohol consumption, physical activity, hypertension, and diabetes. In men, BMI had an inverted J-shaped association with the prevalence of asthma, with an odds ratio of 1.88 (95% confidence interval [CI]: 1.89-2.24) for underweight and 1.12 (95% CIs: 0.97-1.29) for obesity. In women, BMI had a J-shaped association with the prevalence of asthma, with an odds ratio of 1.05 (95% CIs: 0.91-1.22) for underweight and 2.29 (95% CIs: 2.06-2.56) for obesity. In conclusion, in a nationally representative sample of Korean adults, the association between BMI and the prevalence of asthma varied between the sexes. This suggests that malnutrition and obesity are involved in the pathophysiology of asthma.

Prevalence and associated factors for self-reported asthma in a Canadian population: The Canadian Community Health Survey, 2014

BACKGROUND

Asthma prevalence is increasing among adults, yet limited information regarding the association between adult asthma and environmental and personal exposures is available using large nationally representative population-based survey.

OBJECTIVE

To determine the prevalence of asthma and associated factors for self-reported asthma in a Canadian population aged 12 years and older by using the Canadian Community Health Survey (CCHS) 2014 cross-sectional cohort.

METHODS

We used data from the 2014 CCHS. Asthma was determined through self-reported health professional diagnosis. Information regarding covariates of importance, such as socio-economic status, life style variables, was obtained. A weighted logistic regression analysis was performed with appropriate technique for clustering effects.

RESULTS

Estimated self-reported asthma prevalence of 8.1% in the greater than 12 years old Canadian population was observed. We found that a substantial proportion of Canadians (aged 12 and older) reported having asthma and geographical differences and differences between specific provinces in asthma prevalence. Women had higher prevalence of asthma than men, but the relationship depended on age and body mass index (BMI). Interactions between household income and smoking status were observed to predict the probability of asthma.

CONCLUSIONS

Additional studies are needed to determine which factors influence the asthma prevalence between sex, BMI as well as smoking status and household income and its interactions with each other.

Sex difference in the association between obesity and asthma in U.S. adults: Findings from a national study

BACKGROUND

Obesity and asthma are both prevalent in the U.S. The a few studies that have examined the differences in association between obesity and asthma by sex provided mixed results. Reason for the sex differences is not well understood.

OBJECTIVE

Using U.S. nationally representative data we aimed to examine the association between obesity and asthma and potential sex differences.

METHODS

Data were obtained from the 2012 National Health Interview Survey (n = 33,153 adults, 4197 had asthma). Asthma was determined by a positive response to the question "Has a doctor or health care professional ever told you had asthma?" Obesity was determined as a Body Mass Index (BMI)≥30. Obese status was categorized as BMI = 30-34.9 (Class I obesity), BMI = 35-39.9 (Class II obesity), and BMI≥40 (Class III obesity).

RESULTS

The prevalence of asthma was 12.6% (11.0% in men, 14.2% in women), and was higher in the obese than non-obese individuals (16.6% vs. 11.1%, p < 0.0001). After controlling for potential confounders, Class I obesity (OR = 1.27, 95% CI = 1.11-1.44), Class II obesity (OR = 1.55, 95% CI = 1.31-1.84), Class III obesity (OR = 1.85, 95% CI = 1.54-2.21) were positively associated with asthma. The association between Class III obesity and asthma was stronger in women than men (2.11 (1.70-2.63) vs. 1.40 (1.01-1.96), p < 0.05), although the sex difference in the association between BMI and asthma was not significant. Positive associations between class II and class III obesity and asthma were observed among young and middle-aged women compared to young and middle-aged men. Stratified by allergic status, obesity remained being positively associated with asthma.

CONCLUSION

The prevalence of asthma was higher in women than men. Obesity (and BMI) was positively associated with asthma, overall or stratified by allergic status. The association between Class III obesity and asthma was stronger in women. Obesity and sex may be taken into consideration for the management of asthmatic patients.

Obesity, body fat distribution and breast cancer

Abstract Strong epidemiological data exists implicating anthropometric risk factors in breast cancer aetiology. In premenopausal women the risk of breast cancer increases with increased height, yet decreases with increasing weight and BMI. Although the evidence is not strong, a counter-intuitive positive relationship between central adiposity and premenopausal breast cancer risk is emerging. In post-menopausal women an increased risk in breast cancer has been found for all anthropometric measures: height, weight, BMI, measures of central adiposity (waist:hip ratio and waist circumference) and weight gain, with breast size being a possible additional risk factor. Weight loss as a strategy for reducing breast cancer risk seems to offer a viable prophylaxis in obese post-menopausal women, although data are limited. The evidence for anthropometric measures in relation to breast cancer risk is consistently stronger for post-menopausal women compared with premenopausal women and seems to be dependent on age. A number of possible biological mechanisms have been offered to explain the link between breast cancer risk and anthropometric measures. It has been hypothesised that obesity, especially central fat deposits, linked to insulin resistance, increases circulating hormones such as oestrogens, androgens, insulin, insulin-like growth factor-1 (IGF-1), and decreased levels of hormone-binding proteins such as steroid hormone-binding globulin and IGF-1 binding protein-1. Thus there are resulting increased concentrations of bioavailable sex hormones, which have been linked to increased breast cancer risk. As obesity is an important modifiable risk factor, which has been linked to increased post-menopausal breast cancer, public health recommendations to maintain ideal weight throughout life are warranted.

Obesity as a risk factor for development and poor prognosis of breast cancer

The evidence that obesity adversely affects women's health is overwhelming and indisputable. The risk of postmenopausal breast cancer increases with obesity; measured as weight gain, body mass index, waist-hip ratio or percent body fat. It is also established that obesity is associated with poor prognosis of breast cancer. This review examines in detail the possible mechanisms by which obesity causes poor prognosis of breast cancer such as estrogenic activity, advanced or more aggressive disease at diagnosis and high likelihood of both local and systemic treatment failure. After careful consideration of the available evidence, the author concludes that obesity contributes towards development and poor prognosis of breast cancer; therefore, weight management should be an integral part of any strategy to prevent and improve the outcome of breast cancer.

Established breast cancer risk factors by clinically important tumour characteristics

Breast cancer is a morphologically and clinically heterogeneous disease; however, it is less clear how risk factors relate to tumour features. We evaluated risk factors by tumour characteristics (histopathologic type, grade, size, and nodal status) in a population-based case-control of 2386 breast cancers and 2502 controls in Poland. Use of a novel extension of the polytomous logistic regression permitted simultaneous modelling of multiple tumour characteristics. Late age at first full-term birth was associated with increased risk of large (> 2 cm) tumours (odds ratios (95% confidence intervals) 1.19 (1.07-1.33) for a 5-year increase in age), but not smaller tumours (P for heterogeneity adjusting for other tumour features (Phet) = 0.007). On the other hand, multiparity was associated with reduced risk for small tumours (0.76 (0.68-0.86) per additional birth; Phet = 0.004). Consideration of all tumour characteristics simultaneously revealed that current or recent use of combined hormone replacement therapy was associated with risk of small (2.29 (1.66-3.15)) and grade 1 (3.36 (2.22-5.08)) tumours (Phet = 0.05 for size and 0.0008 for grade 1 vs 3), rather than specific histopathologic types (Phet = 0.63 for ductal vs lobular). Finally, elevated body mass index was associated with larger tumour size among both pre- and postmenopausal women (Phet = 0.05 and 0.0001, respectively). None of these relationships were explained by hormone receptor status of the tumours. In conclusion, these data support distinctive risk factor relationships by tumour characteristics of prognostic relevance. These findings might be useful in developing targeted prevention efforts.

Early life factors and incidence of proliferative benign breast disease

Proliferative benign breast disease is a marker of increased breast cancer risk, yet little is known about its etiology. Most studies of benign breast disease have focused only on risk factors in adulthood, despite growing evidence that factors in early life influence breast cancer risk. We explored the relations of several early life factors with incidence of proliferative benign breast disease among 71,896 premenopausal women in the Nurses' Health Study II who recalled their body fatness at young ages, physical activity in adolescence, birthweight, and history of being breastfed. Between 1991 and 1997, 901 of these women were identified as having proliferative benign breast disease from a centralized pathology review. Relative risks (RR) and 95% confidence intervals (95% CI) were estimated from Cox proportional hazards models. Greater childhood body fatness (ages 5-10) was associated with decreased risk of proliferative benign breast disease; the multivariate RR (95% CI) for the most overweight compared with the most lean was 0.61 (0.44-0.86; P(trend) < 0.0001) and remained significant after adjustment for current body mass index. Body mass index at age 18 was also inversely associated with incidence of proliferative benign breast disease, with a multivariate RR (95% CI) of 0.67 (0.52-0.88) for those who were > or =25 kg/m(2) compared with those who were <19 kg/m(2) (P(trend) = 0.001). There were no clear associations for physical activity in adolescence, birthweight, or being breastfed. These results indicate that premenopausal women who were heavier at young ages have lower incidence of proliferative benign breast disease, consistent with previous findings for breast cancer.

Relationship between asthma severity and obesity

The prevalence of both obesity and asthma has risen in recent years. We sought to investigate whether obesity may be related to asthma. We undertook a retrospective medical record review of patient records at an inner-city academic asthma center. Obesity was defined as a body mass index (BMI) greater than 30. Asthma severity was defined by using the National Heart Lung and Blood Institute 1997 guidelines. Adults with a history of cigarette smoking or other lung disease were excluded. A total of 143 individuals aged 18-88 with a mean age of 43.9 met the entry criteria. There were 113 females and 30 males. Seventy-two percent of the sample was obese. The Spearman correlation coefficient showed a linear relationship between asthma severity and BMI (r = 0.40, p < 0.0001). Females with asthma were significantly more overweight than males, mean BMI 35.9 vs. 32.14, respectively (p = 0.01). The prevalence of obesity in the 13 patients on long-term oral corticosteroids was 100%. Prevalence of obesity increases with increasing asthma severity in adults. The association of asthma severity with obesity suggests that obesity may be a potentially modifiable risk factor for asthma or asthma-like symptoms.

Dietary intake, physical activity, body mass index, and childhood asthma in the Third National Health And Nutrition Survey (NHANES III)

Childhood asthma may be affected by dietary changes and increased body mass related to a sedentary lifestyle, although the mechanisms are poorly understood. To test this hypothesis, we used data from the National Health and Nutrition Survey (NHANES III) from 1988-1994, including 7,904 children. We analyzed cross-sectional information on body mass index (BMI = weight/height2), physical activity (hr/day viewing television), dietary intake (24-hr recall), and vitamin C intake (60 mg/day). The probability of self-reported asthma or wheezing relating to risk factors was calculated by logistic regression. After controlling for dietary intake, physical activity, and sociodemographic variables, asthma risk was three times higher for children aged 6-16 years in the highest percentiles of BMI (>95th percentile) when compared to children in percentiles 25-49 (OR = 3.44; 95% CI, 1.49-7.96). No increase was observed in children aged 2-5 years. Low vitamin C intake was marginally related to self-reported current wheezing in children aged 6-16 years. Our results show that increased BMI may influence asthma prevalence in children, but further investigation is needed.

Respiratory complications of obesity

Obesity is known to be a major risk factor of a whole range of cardiovascular, metabolic and respiratory disorders. It has been recognised that the pattern of regional fat distribution plays an important role in the pre-disposition of obese subjects to certain obesity-related complications. Derangement of parameters of lung function is determined to a large extent by the quantity and distribution of excess body fat with its potential to interfere with the mechanics of pulmonary physiology. Clinical, laboratory and epidemiological observations have established links between obesity and several breathing problems including obstructive sleep apnoea, obesity hypoventilation syndrome and asthma. However, in many respects, the pathophysiology of these links is not fully explored. In this article, the impact of obesity on pulmonary physiology and its association with the above-mentioned clinical conditions is discussed.

Sex-race differences in the relationship between obesity and asthma: the behavioral risk factor surveillance system, 2000

PURPOSE

Although prospective data are limited, recent cross-sectional studies support obesity as a cause of asthma. They also suggest that the association is present only among women. Our analysis examines possible sex-race differences in the relationship between obesity and asthma.

METHODS

We examined data from the 2000 Behavioral Risk Factor Surveillance System. To minimize diagnostic bias, the sample was limited to adults aged 18 to 34 years. All cases had doctor-diagnosis of asthma and ongoing symptoms. Multiple logistic regression was used to examine risk factors for current asthma vs. never having asthma.

RESULTS

Obesity and asthma were more strongly related among women than men (test for interaction, p<0.01). Across increasing categories of body mass index (BMI), we observed a dose-response relationship among women (odds ratios: 0.9, 1.0 [reference], 1.0, 1.3, 1.5, 1.8, and 3.2) but only a non-significant increased risk in severely obese men (odd ratio: 2.0). In subgroup analyses, however, the obesity-asthma association was present in four of six sex-race/ethnicity subgroups, including black and Hispanic men.

CONCLUSIONS

Although the obesity-asthma association is stronger among women than men, our analysis demonstrates a strong positive association among men from minority groups. These race-specific results may help explain some of the "inconsistencies" in prior studies.

Effects of obesity on breast cancer stage at diagnosis in Korean women

This study was carried out to test the hypothesis that palpation for lumps may be more difficult in large breasts than in small breasts, resulting in a delay in the detection and diagnosis of breast cancer, and to determine whether this hypothesis is confirmed in Asian women. Of 833 new breast cancer patients registered in the Daegu Cancer Registry in 1997-1999, 579 were used in the final data analysis, after excluding patient records containing many missing data on study variables related with cancer staging. There was no difference in means of body mass index (BMI) according to tumour, either in all cases or in those under 49 years of age. In the 50+ age group, the means+/-standard deviations of BMI of T1, T2 and T3 were 23.7+/-2.8, 24.2+/-3.0, and 26.2+/-4.3, respectively (P=0.01). In univariate logistic regression of tumour characteristics with BMI, no statistically significant odds ratios were found either by continuous or quartiles of BMI. In conclusion, these results suggest that the hypothesis is partially confirmed in Korean breast cancer patients and further studies are needed to clarify the relationship between BMI and tumour stage at diagnosis.

Breast cancer and obesity: an update

Obesity has a complicated relationship to both breast cancer risk and the clinical behavior of the established disease. In postmenopausal women, particularly the elderly, various measures of obesity have been positively associated with risk. However, before menopause increased body weight is inversely related to breast cancer risk. In both premenopausal and postmenopausal breast cancer, the mechanisms by which body weight and obesity affect risk have been related to estrogenic activity. Obesity has also been related to advanced disease at diagnosis and with a poor prognosis in both premenopausal and postmenopausal breast cancer. Breast cancer in African-American women, considering its relationship to obesity, exhibits some important differences from those described in white women, although the high prevalence of obesity in African-American women may contribute to the relatively poor prognosis compared with white American women. Despite the emphasis on estrogens to explain the effects of obesity on breast cancer, other factors may prove to be equally or more important, particularly as they relate to expression of an aggressive tumor phenotype. Among these, this review serves to stress insulin, insulin-like growth factor-I, and leptin, and their relationship to angiogenesis, and transcriptional factors.

Obesity influences outcome of sentinel lymph node biopsy in early-stage breast cancer

BACKGROUND

Sentinel lymph node biopsy is a rapidly emerging standard of care for staging the axilla in invasive breast cancer. Factors influencing success must be identified to understand the procedure's limitations and challenges. Increasing body mass with age has an inverse relationship to success. A proportion of SLN biopsy patients are both senior and overweight, so measurement of the body mass to age relationship is essential.

STUDY DESIGN

We reviewed mapping successes and failures in 2,495 SLN biopsy procedures performed between September 1996 and June 2001. Clinical stage T1 N0 to T3 N0 breast cancer cases were included. We used a combined technique (radioisotope and blue dye) to detect SLNs. Failure was defined as the inability to identify any nodes with either blue dye or by in vivo counts. Body- mass index (BMI) for each patient was measured by height and weight data (kg/m(2)), and cases were stratified by BMI and age.

RESULTS

Among 2,495 cases, there were 62 failed and 2,433 successful mappings (failure rate = 2.48%). Mean age, weight, and BMI were significantly higher in the failure group. The success of SLN biopsy was inversely related to BMI (r = -0.98, p = 0.002). When stratified by patient age (< 50 versus > or =50 years), this relationship was more pronounced in the > or = 50 group. Multivariate analysis of age, weight, and BMI found age (p = 0.011) and BMI (p = 0.00001) to be predictive of SLN mapping success, with weight alone not significant.

CONCLUSIONS

Increasing age and BMI do not appear to be contraindications for SLN biopsy. Rather, surgeons should be aware that increasing body mass and age are potential risk factors for a failed procedure, in which case a completion axillary node dissection for staging is required.

Exposures in childhood, adolescence and early adulthood and breast cancer risk: a systematic review of the literature

A growing body of work indicates that exposures over the life course have important roles to play in the aetiology of breast cancer. This review synthesises the literature that has been published in the area of early life events and female breast cancer risk. The review finds some evidence, primarily from cohort studies on the relationship between birthweight and breast cancer, to suggest that in utero events are related to breast cancer risk in adulthood. Strong evidence to support a positive association between height and breast cancer exists. Postulated mechanisms for this relationship include the role of early diet in subsequent disease risk, and the influence of endogenous growth factors mediating the relationship. There is some evidence to suggest that leg length is the component of height which is generating the observed associations between height and breast cancer. There is no consistent pattern of association between relative weight in childhood or adolescence and risk of breast cancer. The evidence to suggest an association between physical activity in early life and breast cancer risk is convincing from case-control studies, but is not fully substantiated by the results of three cohort studies. There are inconsistent results regarding the association between smoking at a young age and breast cancer risk. There is little evidence for an association between passive smoking in early life and breast cancer risk. No clear association between early drinking and breast cancer risk exists. These results are discussed in relation to possible underlying mechanisms and health promotion strategies which could reduce breast cancer risk.

Can obesity explain the racial difference in stage of breast cancer at diagnosis between black and white women?

OBJECTIVE

Black women are more likely to be diagnosed at a more advanced stage of breast cancer than are white women. Traditionally, this has been attributed in part to social or cultural factors. Given that black women are more likely to be obese than white women and that being obese is associated with a more advanced stage at diagnosis, this study aims to assess to what extent the racial difference in stage at diagnosis can be explained by racial differences in obesity.

METHODS

Incident cases of breast cancer between 1991 and 1997 (white, n = 585; black, n = 381) were identified from hospitals in the Baltimore metropolitan area. Information, including age, race, weight, height, and pathology reports, was obtained from hospital medical records.

RESULTS

Black women were more likely than white women to be diagnosed with breast cancer at tumor-node-metastasis (TNM) stage II or greater (age-adjusted odds ratio [OR] = 1.51, 95% confidence interval [CI] 1.15-1.99). Further, black women were more likely than white women to be overweight or obese. A high body mass index (BMI) was significantly associated with an advanced stage of breast cancer at diagnosis. Adjustment for the higher prevalence of obesity in black women attenuated the risk estimate of more advanced stage of breast cancer at diagnosis in black women compared with white women by approximately 30%.

CONCLUSIONS

Our results suggest that the higher prevalence of obesity among black women plays an important role in explaining their relative disadvantage in stage at diagnosis of breast cancer. Nonetheless, a racial difference in stage of breast cancer at diagnosis persists after adjustment for obesity.

Weight gain in women with breast cancer treated with adjuvant cyclophosphomide, methotrexate and 5-fluorouracil. Analysis of resting energy expenditure and body composition

BACKGROUND

Weight gain is a common side effect observed in women undergoing adjuvant chemotherapy for breast cancer. Among possible causes a direct effect of chemotherapy on metabolism has been proposed. Body composition variations after adjuvant chemotherapy suggest the occurrence of sarcopenic obesity, possibly due to ovarian failure. We investigated acute and chronic effects of adjuvant chemotherapy on body weight, resting energy expenditure (REE) and plasma catecholamines in a group of menopausal women.

PATIENTS AND METHODS

Thirty menopausal women with stage I-II breast cancer were recruited for the study. We measured REE and respiratory quotient (RQ) and body composition at the beginning and after 3 and 6 months of adjuvant cyclophosphomide, methotrexate, and 5-fluorouracil (CMF). REE, RQ, and plasma catecholamines were assessed before and after each chemotherapy session. At each session food intake was also assessed in all patients, by a food diary. Seven patients out of the group of 30 were also evaluated after a placebo infusion (saline).

RESULTS

A significant weight gain was observed in all women (70.5 +/- 3 v.s. 67.7 +/- 3 kg, p < 0.001), with increase in both fat-free mass (FFM) (45.2 +/- 1.5 v.s. 43.6 +/- 1.3 kg, p < 0.001) and fat-mass (FM) (25.3 +/- 1.7 v.s. 24.1 +/- 1.8 kg, p < 0.005). A decrease in REE and RQ was observed both during CMF and placebo infusion (p < 0.05). During acute CMF and placebo infusion a reduction of plasma levels of noradrenaline was observed at the first and last session. REE increased progressively during the study period.

CONCLUSIONS

CMF therapy apparently has no effect on REE either acutely or during a 6-month-period; the increased REE observed in the long-term is likely due to the concomitant increase in FFM. The lack of evidence of sarcopenic obesity, at variance with previous literature, is likely due to different patient selection.

Patient delay and stage of diagnosis among breast cancer patients in Germany -- a population based study

Early diagnosis is a tenet in oncology and should enable early treatment with the expectation of improved outcome. Extent and determinants of patient delay of diagnosis in breast cancer patients and its impact on stage of disease were examined in a population based study among female breast cancer patients in Germany. Two hundred and eighty-seven women, aged 18 to 80 years with newly diagnosed invasive symptomatic breast cancer, were interviewed with respect to the diagnostic process. Patient delay was defined as time from onset of first symptoms to first consultation of a doctor. Median patient delay was 16 days among symptomatic patients. Eighteen per cent of all breast cancer patients waited longer than 3 months before consulting a physician. Long patient delay was associated with old age, history of a benign mastopathy, obesity, and indices of health behaviour such as not knowing a gynaecologist for out-patient care and non-participation in general health screening examinations. A strong association between patient delay and stage at diagnosis was observed for poorly differentiated tumours. These results suggest that at risk groups for delaying consultation can be identified and that a substantial proportion of late stage diagnoses of poorly differentiated breast cancer cases could be avoided if all patients with breast cancer symptoms would present to a doctor within 1 month.

Body mass and stage of breast cancer at diagnosis

Obesity is a well-known risk factor for postmenopausal breast cancer. In contrast, the relationship between obesity and stage of breast cancer at diagnosis is less clear. We hypothesized that increased breast size in obese women may delay discovery of breast tumors. Thus, the purpose of our study was to examine whether there is an association between body mass and stage of breast cancer at diagnosis using hospital medical records. Newly diagnosed breast cancer cases (n = 966) in the Baltimore metropolitan area from 1991 to 1997 were included in our study. Patient information including age, ethnicity, weight, height and pathology data were obtained from hospital medical records. High body mass was significantly associated with late stage of breast cancer at diagnosis. Women who were obese (body mass index [BMI] > or = 27.3) were more likely to be at an advanced stage at diagnosis compared with women with a BMI of < 27.3 (multivariate-adjusted odds ratio [OR] 1.57, 95% confidence interval [CI] 1.15-2.14). The association between body mass and stage at diagnosis was stronger among women younger than 50 years (OR 2.34, 95% CI 1.34-4.08) compared with women 50 years or older (OR 1.30, 95% CI 0.89-1.91). Our study suggests that higher body mass is associated with advanced stage of breast cancer at diagnosis. This finding may be of considerable concern, given the increasing prevalence of obesity in women in the United States and the poor prognosis associated with late-stage tumors.

Socio-demographic factors, health behavior and late-stage diagnosis of breast cancer in Germany: a population-based study

Late-stage diagnosis of breast cancer is associated with poor survival. Identification of individuals at high risk of late-stage diagnosis could be an effective step to reduce breast cancer mortality. We examined the association of socio-demographic factors and health behavior with breast cancer stage in a population-based sample of 380 female breast cancer patients in Saarland, Germany. Overall, 182 women (47.9%) were diagnosed with late-stage (regional or distant) breast cancer. After control for potential confounding by multivariate logistic regression, an increased risk of late-stage diagnosis was observed for older age (OR = 1.8; 95% CI 1.0-3.2), foreign nationality (OR = 3.9; 95% CI 0.7-20.8), living in large households (OR = 1.7; 95% CI 1.0-2.9), non-participation in general health check-up (OR = 1.5; 95% CI 0.9-2.4) and low interest in health care (OR = 1.6; 95% CI 1.0-2.7). The proportion of late-stage cancer was clearly decreased when tumors were detected by screening (OR = 0.4; 95% CI 0.2-0.8). Certain socio-demographic factors and characteristics of health behavior seem to represent independent risk indicators of late-stage diagnosis.

Low body mass index is an independent predictive factor of local recurrence after conservative treatment for breast cancer

BACKGROUND

Obesity or increased body mass index (BMI) has been shown to have two important adverse effects related to breast cancer. First, several studies have identified an association between increased BMI and advanced stage breast cancer. Second, increased BMI has been shown to be associated with poorer prognosis. In a previous report, we had identified low BMI as a risk factor for local reccurence at five years. The objectives of this study were to evaluate the relationship between BMI and local control and to confirm this prognostic factor in a larger population with an important follow-up.

MATERIALS AND METHODS

Between 1976 and 1988, 605 women with invasive breast carcinoma less than 4 cm in diameter underwent conservative surgery with axillary dissection and radiation therapy. The median follow-up time was 82 months. The risk of local recurrence and distant metastasis was evaluated by univariate retrospective analysis using Kaplan-Meier method for the main clinical and histologic factors. Those found to be significant were entered in a Cox model for multivariate analysis.

RESULTS

Since the beginning of the study, 80 patients had developed local recurrence. The 5 years and 10 years local control rates were 91% and 83%, respectively. Four parameters were independent predictive factors of local recurrence: Age lower than 40 years (HR = 2.42 95% CI = [1.35-4.34]), BMI: elevation of one unit reducing the local recurrence of 0.92 95%CI = [0.85-0.99], multifocality of the tumor on pathological examination (HR = 2.12 95% CI = [1.16-3.88]) and positive axillary nodes HR = 0.54 95% CI = [0.31-0.95]. Size of the breast was not a predictive factor for local cancer recurrence. Low BMI did not increase risk of distant.

CONCLUSION

Our study offers new data concerning the possibility that thinness may be related to local recurrence of breast cancer.

Review of anthropometric factors and breast cancer risk

Epidemiological evidence implicating anthropometric risk factors in breast cancer aetiology is accumulating. For premenopausal women, breast cancer risk increases with increasing height, but decreases with higher weight or body mass index, and no association with increased central adiposity exists. For postmenopausal women, an increased risk of breast cancer is found with increasing levels of all the anthropometric variables including height, weight, body mass index, waist-hip ratio, waist circumference and weight gain. Weight loss appears to decrease risk, particularly if it occurs later in life. Breast size may be a risk factor for breast cancer, however, the current evidence is inconclusive. Several hypothesized biologic mechanisms exist to explain how anthropometric factors influence breast cancer risk. Obesity may increase levels of circulating endogenous sex hormones, insulin and insulin-like growth factors that all, in turn, increase breast cancer risk. Genetic predisposition to obesity and to specific body fat distributions are also implicated. With obesity, there are increased levels of fat tissue that can store toxins and can serve as a continuous source of carcinogens. Recommendations for future research on anthropometric factors and breast cancer are provided. Sufficient evidence exists to support strategies to avoid weight gain throughout life as a means of reducing postmenopausal breast cancer risk.

Risk factors for benign proliferative breast disease

BACKGROUND

As part of a nested case-control study of benign proliferative breast disease (BPBD) conducted within the cohort of women participating in the Alberta breast screening programme, an analysis of all women who had a benign breast biopsy between 1990 and 1995 was undertaken to identify the epidemiological risk factors for BPBD.

METHODS

The breast biopsies of all eligible women were re-reviewed by a panel of four pathologists using Page's classification for benign breast disease. Cases were 165 women whose biopsies, upon review, showed benign breast tissue changes ranging from sclerosing adenosis to atypical ductal hyperplasia. Controls were 217 women whose biopsies showed no evidence of any proliferative or neoplastic changes. In-person interviews were conducted with all study subjects.

RESULTS

Women with >/=25% fibroglandular breast tissue density, as compared to women with <25% density, experienced nearly a doubling in risk of BPBD (OR = 1.91, 95% CI : 1.24-2.94). All other possible risk factors examined were not associated with BPBD.

CONCLUSION

This study suggests that fibroglandular tissue density may be a risk factor, or marker, for increased risk of BPBD.

Effect of obesity on screening mammography: outcomes analysis of 88,346 consecutive examinations

OBJECTIVE

We determined differences in the rates of recall, biopsy, and cancer detection for screening mammography as a function of adiposity.

MATERIALS AND METHODS

Eighty-eight thousand three hundred forty-six consecutive screening mammography examinations were performed from April 1985 to August 1997. Patient weights were normalized to ideal weight correcting for height and were subdivided into adiposity cohorts including underweight by greater than 10%; ideal weight +/- 10%; overweight by 11-24%; overweight by 25-39%; and overweight by greater than 40%. The rates of recall, biopsy, cancer detection, and cancer stage were calculated and were analyzed using the chi-square test for trend. Cancer size was analyzed using linear regression analysis.

RESULTS

Reliable (p < 0.05) and meaningful differences were seen between cohorts of increasing adiposity for rates of recall, biopsy, and cancer detection. An increase in recall rate occurred with progressively increasing adiposity (3.88%, 4.89%, 5.11%, 5.47%, 5.55% [p < 0.0001]). The rate of biopsy also increased with increasing adiposity (0.98%, 1.31%, 1.35%, 1.59%, 1.65% [p < 0.0002]), as did the rate of screening-detected cancer (number of cases of cancer per 1000 women screened) (3.74, 4.29, 5.34, 4.70, 6.04 [p < 0.015]). Finally, increased adiposity also correlated with increased median cancer size (p < 0.02) and with more advanced stage at diagnosis (p = 0.046).

CONCLUSION

Increasing adiposity correlates with progressive increases in the rates of recall, biopsy, and cancer detection for women undergoing screening mammography. Increasing adiposity also correlates with increased cancer size and stage, providing further support for obesity as a risk factor for breast cancer.

Migration patterns and breast carcinoma

BACKGROUND

Many American Indian and Alaska Native women have lower incidence rates of breast carcinoma than other racial/ethnic groups in the United States. The rates in most areas, however, have increased in recent years. The author reviews the migration patterns and effects that might contribute to this change.

METHODS

A review of the literature on migration and breast carcinoma incidence was conducted.

RESULTS

Migration significantly impacts on breast carcinoma incidence in all groups of women studied.

CONCLUSIONS

Research must be designed that will explore the components of host, life-styles, and environment on breast carcinoma rates in American Indian and Alaska Native women to elucidate mechanisms of breast carcinoma etiology.

Stage of breast cancer in relation to body mass index and bra cup size

Most studies on women with breast cancer indicate that obesity is positively associated with late-stage disease. Some results have shown a similar relationship between breast size and stage. A recent study found that the association between body mass index (BMI) and stage was limited to cancers that were self-detected, suggesting that the BMI-stage relation may be due to delayed symptom recognition. We examined the relationships between stage and both BMI and breast (bra cup) size, stratified by method of detection, using data from a population-based case-control study of 1,361 women (ages 20-44 years) diagnosed with breast cancer during 1990-1992. Height and weight measurements and information on bra cup size, method of cancer detection and other factors predictive of stage at diagnosis were collected during in-person interviews. A case-case comparison was conducted using logistic regression to estimate odds of regional or distant stage rather than local stage in relation to BMI and bra size. Odds of late-stage disease were increased with higher BMI [adjusted odds ratio (OR) for highest to lowest tertile = 1.46, 95% confidence interval (CI) 1.10-1.93] and larger bra cup size (OR for cup D vs. cup A = 1.61, 95% CI 1.04-2.48). These relationships were not modified by the method of detection. Differences in etiologic effects, rather than differences in detection methods, may explain the relations observed between stage and both BMI and breast size.

The influence of maternal diet on breast cancer risk among female offspring

The induction of breast cancer is a long process, containing a series of biological events that drive a normal mammary cell towards malignant growth. However, it is not known when the initiation of breast cancer occurs. One hypothesis is that a high estrogenic environment during the perinatal period increases subsequent breast cancer risk. There are many sources of extragonadal estrogens, particularly in the diet. The purpose of this paper is to review the evidence that a high maternal intake of dietary fats increases serum estrogens during pregnancy and increases breast cancer risk in daughters. Our animal studies show that a high maternal consumption of corn oil consisting mainly of linoleic acid (omega-6 polyunsaturated fatty acid, PUFA), increases both circulating estradiol (E2) levels during pregnancy and the risk of developing carcinogen-induced mammary tumors among the female rat offspring. A similar increase in breast cancer risk occurs in female offspring exposed to injections of E2 through their pregnant mother. Our data suggest that the mechanisms by which an early exposure to dietary fat and/or estrogens increases breast cancer risk is related to reduced differentiation of the mammary epithelial tree and increased number of mammary epithelial cell structures that are known to the sites of neoplastic transformation. These findings may reflect our data of the reduced estrogen receptor protein levels and protein kinase C activity in the developing mammary glands of female rats exposed to a high-fat diet in utero. In summary, a high dietary linoleic acid intake can elevate pregnancy estrogen levels and this, possibly by altering mammary gland morphology and expression of fat- and/or estrogen-regulated genes, can increase breast cancer risk in the offspring. If true for women, breast cancer prevention in daughters may include modulating the mother's pregnancy intake of some dietary fats.

Birth weight, body mass index and asthma in young adults

BACKGROUND

Impaired fetal growth may be a risk factor for asthma although evidence in children is conflicting and there are few data in adults. Little is known about risk factors which may influence asthma in late childhood or early adult life. Whilst there are clues that fatness may be important, this has been little studied in young adults. The relations between birth weight and childhood and adult anthropometry and asthma, wheeze, hayfever, and eczema were investigated in a nationally representative sample of young British adults.

METHODS

A total of 8960 individuals from the 1970 British Cohort Study (BCS70) were studied. They had recently responded to a questionnaire at 26 years of age in which they were asked whether they had suffered from asthma, wheeze, hayfever, and eczema in the previous 12 months. Adult body mass index (BMI) was calculated from reported height and weight.

RESULTS

The prevalence of asthma at 26 years fell with increasing birth weight. After controlling for potential confounding factors, the odds ratio comparing the lowest birth weight group (<2 kg) with the modal group (3-3.5 kg) was 1.99 (95% CI 0.96 to 4.12). The prevalence of asthma increased with increasing adult BMI. After controlling for birth weight and other confounders, the odds ratio comparing highest with lowest quintile was 1.72 (95% CI 1.29 to 2.29). The association between fatness and asthma was stronger in women; odds ratios comparing overweight women (BMI 25-29.99) and obese women (BMI >/=30) with those of normal weight (BMI <25) were 1.51 (95% CI 1.11 to 2.06) and 1.84 (95% CI 1. 19 to 2.84), respectively. The BMI at 10 years was not related to adult asthma. Similar associations with birth weight and adult BMI were present for wheeze but not for hayfever or eczema.

CONCLUSIONS

Impaired fetal growth and adult fatness are risk factors for adult asthma.

Improved screening for breast cancer associated with a telephone-based risk assessment

BACKGROUND

Our objective was to develop and field-test a telephone-based breast cancer risk assessment and to assess its efficacy in improving screening behavior. The study was performed at a financial institution and a manufacturing corporation with main offices in Boston, Massachusetts, and branch offices in various regions of the United States.

METHODS

A longitudinal study consisting of an initial health risk assessment administered by telephone, with a subsequent follow-up study initiated 8 months later, was performed. Study design was influenced by some of the suggestions made by the benefits departments of the corporate sponsors. A voice-response, telephone system collected risk information from callers and gave real-time risk assessment. These callers could receive a risk assessment over the phone and remain completely anonymous or furnish name and address to receive a more detailed written report. Main outcome measures included the response rate and demographics of the respondents, risk profiles of the callers, and breast cancer screening statuses.

RESULTS

There were 343 participants of whom 189 relinquished anonymity to receive more detailed information by mail and were available for a follow-up study. Sixty-three women (18%) reported a family history of breast cancer, with 34 women (10%) responding that one first-degree blood relative had been diagnosed before the age of 50. A strong positive correlation between the level of familial risk and the decision to remain anonymous existed (P < 0.0001). There was an increase in compliance with breast self-examination from 34% (40/119) at time of use of the system to 62% (74/119) at follow-up, P < 0.0001. Clinical breast exams showed similar improvements, from 82 (98/119) to 92% (110/119), P < 0.0137. Paired and unpaired data of women 40 years of age and older indicate an improvement in mammography compliance from time of system use to follow-up, 76 (22/29) to 93% (27/29), P < 0.0572, and 79 (33/42) to 93% (27/29), P < 0.0129, respectively.

CONCLUSIONS

A population of women with a risk profile higher than that of the U.S. population called the survey. System use is associated with an improvement in breast cancer screening habits. Self-reported, increased genetic risk for breast cancer was strongly correlated with a decision to remain anonymous.

Estrogen-regulated non-reproductive behaviors and breast cancer risk: animal models and human studies

The possible role of personality patterns and psychosocial factors in breast cancer has been studied extensively, through both human and animal experiments. The data are conflicting, and the conclusions controversial. This review will serve two purposes. First, we present evidence that behavioral patterns most commonly linked to breast cancer risk are at least partly regulated by estrogens. This section will suggest that some estrogen-regulated behaviors may be markers of increased breast cancer risk. Second, we will briefly review recent findings in animals connecting psychosocial factors to cancer. We also will address the plausible biological mechanisms. The literature suggests that estrogens, particularly when exposure occurs during the critical developmental periods, such as in utero, puberty, pregnancy, and menopause, influence affective behaviors and increase breast cancer risk. The affective behaviors include depression, aggression, and alcohol intake. Thus, psychosocial and personality factors do not necessarily have a direct impact on breast cancer risk; instead, estrogens have a dual effect on behavior and on the breast.

Weight gain in women diagnosed with breast cancer

This review of the literature indicates that weight gain is a common observation among women after the diagnosis of breast cancer. Gains in weight range from 0 to 50 lb and are influenced by menopausal status; nodal status; and the type, duration, and intensity of treatment. Weight gain appears to be greater among premenopausal women; among those who are node positive; and among those receiving higher dose, longer duration, and multiagent regimens. Psychosocial research suggests that weight gain has a profoundly negative impact on quality of life in patients with breast cancer. Recent findings also suggest that weight gain during therapy may increase the risk of recurrence and decrease survival. Although weight gain in patients with breast cancer is clinically well appreciated, little research has been conducted to investigate the underlying mechanisms of energy imbalance. Changes in rates of metabolism, physical activity, and dietary intake are all plausible mechanisms and call for more research. Further study will provide valuable insight into the problem of weight gain and encourage effective interventions to improve the quality and quantity of life for the woman with breast cancer. Until more is known, however, dietetics practitioners will have to monitor and work individually with patients with breast cancer and use empirical approaches to achieve the important goal of weight management.

Exercise and cancer: linkages with obesity?

This review examines possible protection against various types of tumors from both occupational and leisure-time physical activity. A growing number of well-controlled studies suggest that both hard physical work and an active leisure reduce the overall incidence of cancer. Benefit is demonstrated most clearly for colonic tumors; here, benefit persists after control of the data for body mass index, and a likely mechanism is the speeding of colonic transit, with a resulting decrease in exposure to carcinogens. There are occasional reports of protection against tumors of the breast, reproductive tract, and other body organs. In some of these latter sites, potential mechanisms of protection include a suppression of sex hormone secretion and reduction of body fat depots, where androgens are converted to toxic estrogen derivatives. While vigorous athletic participation may well modulate hormone output, a reduction of body fat is a more likely explanation of any benefit from more moderate physical activity. Protection against cancer is unlikely to become a major argument for an active lifestyle, but it is nevertheless a useful byproduct of physical activity undertaken with other health objectives.

Body mass and breast cancer. Relationship between method of detection and stage of disease

BACKGROUND

Obesity is associated with advanced stage breast cancer at diagnosis and a poorer prognosis. Stage of breast cancer at diagnosis is also strongly influenced by the method of cancer detection. The objective of this study was to determine the relationship between body mass index (BMI) and breast cancer disease stage, taking into account the method of cancer detection (i.e., self-detection, screening mammography, and clinical breast examination [CBE]).

METHODS

From 1988 to 1990, 2863 patients with invasive breast cancer were identified through a statewide, population-based, cancer reporting system and were interviewed as part of a larger study of breast cancer etiology. Stage of disease was classified as either localized or nonlocalized (regional and distant disease combined). The relation between BMI and disease stage was examined by using multiple logistic regression adjusting for age, education, race, year of diagnosis, and prior mammography use.

RESULTS

Thirty-eight percent (1092 of 2863) of the women had nonlocalized breast cancer. A strong dose-response relationship was observed between increased BMI and the likelihood of nonlocalized disease (P < 0.001). However, this association was present only among the 55% of women (1585 of 2863) who self-detected their tumors. The odds ratios for nonlocalized cancer increased from 1.0 for the lowest quintile of BMI to 1.3, 1.6, 1.7, and 1.8 for the second through fifth quintiles, respectively, for this group.

CONCLUSIONS

Greater body mass was associated with nonlocalized breast cancer; however, this association was restricted to women who detected their own cancer. No association was found between BMI and stage of disease among cases detected by either mammography or CBE.

Serum vitamin E level in patients with breast cancer

In this study, the serum vitamin E (total tocopherol) levels in patients with breast cancer (n = 100) and healthy controls (n = 70) were measured. The mean values for vitamin E were found to be 0.44 mg/100 ml in breast cancer patients and 1.108 mg/100 ml in controls. In the statistical evaluation, the vitamin E levels in breast cancer patients are significantly lower than in the controls (P < 0.05). The influence of factors such as suckling period, age of first gestation, smoking status and dietary habits were also studied.

Obesity and subcutaneous fat patterning in relation to survival of postmenopausal breast cancer patients participating in the DOM-project

The effect of obesity and fat distribution on survival of breast cancer patients was studied prospectively in 241 women with a natural menopause who participated in a breast cancer screening project, the DOM-project in Utrecht, The Netherlands. Mean follow-up time was 9.1 years and endpoint of interest was death from breast cancer. Fat distribution was assessed by contrasting groups of subscapular and triceps skinfold thickness. No significant differences in survival time between more obese (Quetelet's index > or = 26 kg/m2) and leaner (Quetelet's index < 26 kg/m2) patients or between patients with central fat distribution and patients with peripheral fat distribution were observed. Analyses were stratified by axillary node status, estrogen receptor status, and way of detection (by first screening or afterwards). Results of the stratified analyses were suggestive of a modifying effect of these factors. The absence of an association between obesity and survival time might be explained by two counteracting mechanisms. On the one hand obesity might be related to impaired survival, due to a tumor growth promoting effect of extra-ovarian estrogens. On the other hand obesity might be related to improved survival in a screened population, because obese patients profit more from screening by earlier detection of tumors than leaner counterparts.

Timing of weight gain in relation to breast cancer risk

Excessive weight gain in women at the time of intense hormonal change can result in metabolic dysfunction. The metabolic/endocrine effect of puberty, pregnancy or menopause on breast tissue 'aging' is likely to be more relevant to a woman's breast cancer risk than is her degree of obesity at the time when the cancer presents. Experimental evidence suggests that the susceptibility of mammary tissue to carcinogenesis is greatest in early adult life, and multiple studies show that a history of weight gain in early adult life is associated with increased breast cancer risk in Western women. Excessive weight gain in that age group is associated with the development of hyperinsulinaemia in individuals with genetic susceptibility to insulin resistance. The insulin resistance syndrome may be a metabolic link between weight gain and breast cancer risk in Western women. Some studies suggest that in postmenopausal women, hyperinsulinaemia is related more to overall obesity, whereas in premenopausal women it is related more to abdominal localisation of fat. This may explain why an increased body mass index is a risk marker for breast cancer in postmenopausal but not premenopausal women. (A premenopausal woman with an average body mass index may have a large intra-abdominal fat mass associated with the presence of hyperinsulinaemia.) It is hypothesised that over-nutrition and inadequate physical exercise favour the development of hyperinsulinaemia and also increase breast cancer risk in women with a genetic susceptibility to both conditions. The hypothesis can be tested by specific intervention studies.

The relation of body size to plasma levels of estrogens and androgens in premenopausal women (Maryland, United States)

We analyzed data from a cross-sectional study of 107 premenopausal women to evaluate the relations of height, weight, and body mass index (BMI) with plasma hormone levels. Participants were 20- to 40-year old women residing in Maryland (United States), whose reported menstrual cycle lengths were not more than 35 days and whose measured weights for height were 85 to 130 percent of 'desirable' based on 1983 Metropolitan Life Insurance tables. Fasting blood specimens were collected on each of days 5-7, 12-15, and 21-23 of every participant's menstrual cycle and pooled to create follicular, midcycle, and luteal phase samples, respectively, for analysis. Adjusted for age, taller women had significantly higher follicular-phase plasma-estradiol levels (percent difference/cm = 1.5, 95 percent confidence interval [CI] = 0.3-2.7, and heavier women had significantly lower plasma sex-hormone binding globulin (SHBG) levels averaged across the menstrual cycle phases (percent difference/kg = -1.2; CI = -1.9-(-0.6). Body weight within the range studied, however, was not related significantly to the concentration of SHBG-bound estradiol during any phase of the menstrual cycle. The results of this cross-sectional study suggest a possible mechanism by which height may influence breast cancer risk.

An examination of obesity and breast cancer survival in post-menopausal women

A historical prospective study was conducted at the Mercy Hospital of Pittsburgh, Pennsylvania (USA), to study the role of post-menopausal obesity in the recurrence and survival of breast cancer. Records from 301 post-menopausal women diagnosed with breast cancer from 1977 to 1985 were followed for at least 5 years from data supplied by the Tumor Registry and medical records. Data collected included age, height, weight, race, hormone receptor status, stage and size of tumour, number of positive nodes, site of distant metastasis, first course of treatment, and 5 year recurrence and survival. Forty-five per cent of patients were obese (n = 136), while 55% were non-obese (n = 165). Obesity was defined by the Quetelet index (patients with values > 27 were considered obese). The recurrence rates for the obese and non-obese groups were 40% and 39% respectively, and were not significantly different. Univariate and multivariate analyses showed that there was no significant association between obesity in post-menopausal women and likelihood of recurrence of or death from breast cancer.

Anthropometry and breast cancer. Body size--a moving target

Body size is one of the few breast cancer risk factors that can be modified throughout life and therefore should be considered in research on breast cancer prevention. The contrasting effects of body size on premenopausal breast cancer compared with postmenopausal breast cancer and the lack of a strong association between body mass and postmenopausal breast cancer in some cohort studies has led to a view that obesity has little influence on breast cancer risk. These conclusions are based on analyses that consider relative weight at one point in time as an adequate measure of lifelong weight patterns and their metabolic consequences. Recent research suggests that, compared to body mass indices, adult weight gain and increased central body fat may be more specific markers of the metabolic consequences of obesity and therefore may predict health outcomes more consistently. Adult weight gain and increases in central body fat, which commonly occur during menopause, have been associated consistently with an increased risk of postmenopausal breast cancer. The timing of weight gain also appears to influence breast cancer risk; increased relative weight and weight gain after menopause have been associated with the largest increases in relative risks. Overall levels of adiposity, increased central fat deposition, and weight gain are associated with alterations in ovarian hormone and glucose metabolism and in growth factors that may promote breast cancer cell growth. Data on lifelong weight changes and the location of fat depots may more precisely identify women with high risk patterns of sex steroid and glucose metabolism. Similarly, research is needed to determine if weight gain during periods of hormonal change, such as menarche, pregnancy, and menopause, have different biologic effects, perhaps because of differences in the location of fat deposition during these periods. Research also is needed on whether there are critical times relative to breast cancer promotion when excessive weight gain should be avoided. Data are lacking on the influence of weight loss or avoidance of weight gain on breast cancer risk or prognosis.

DMBA-induced mammary tumor growth in rats exhibiting increased or decreased ability to cope with stress due to early postnatal handling or antidepressant treatment

Depression and an ability to cope with stress are suggested to play a role in the vulnerability to breast cancer. In rats, neonatal clomipramine administration induces subsequent behavioral abnormalities that closely resemble those seen in human endogenous depression. Early postnatal handling, on the other hand, improves subsequent ability to cope with stress in rodents. The present study examined whether early clomipramine treatment or handling influences the growth of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in female Sprague-Dawley rats. Between postnatal days 5 and 20, rat pups were injected daily with 25 mg/kg clomipramine, handled either by holding them in a hand (H-handling) or by giving them a saline injection (I-handling), or left nonhandled. During these manipulations, but not later, body weight gain was lower in the I-handled and clomipramine-treated pups than in the H-handled rats. As adults, the time spent immobile in the swim test, a model of depressive behavior and an ability to cope with stress, was significantly lengthened in the clomipramine-treated female rats, and shortened in the handled females. Measurement of plasma 17-beta-estradiol (E2) did not reveal any significant differences between the groups. The percentage of animals developing mammary tumors was significantly higher, and the length of survival shorter among the clomipramine-treated rats than among the I-handled rats. However, both groups exhibited less tumors and longer survival than the nonhandled controls. There were no differences in mammary tumor incidence or survival between the nonhandled and H-handled rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Variation in body fat distribution and breast cancer risk in the families of patients with breast cancer and control families

BACKGROUND

The pattern of body fat distribution in women has been correlated with the risk of developing breast and endometrial cancer. The authors determined whether body fat distribution varied between first-degree relatives of patients with breast cancer and in cancer-free families by comparing the body fat distribution of first-degree relatives of patients with breast cancer with age and Quetelet Index-matched controls.

METHODS

Fifty-six first-degree relatives of newly diagnosed patients with breast cancer were compared with 56 controls (non-cancer family members) matched for age and Quetelet Index and were studied for variation in body fat distribution. Anthropometric measurements were taken for the abdomen, thigh, suprailiac, subscapular, biceps, and triceps skinfold thickness; waist and hip circumference; weight; and height. The distribution of body measurements and derived ratios in both case and control family members were compared using the Student t test.

RESULTS

A significant variation in body fat distribution occurred among first-degree relatives in breast cancer and control families. In families with a history of breast cancer, first-degree family members were found to have significantly greater waist:hip ratio (P < 0.001) compared with controls without family history matched for age and Quetelet Index. Other variables indicating upper body fat localization, such as abdomen and suprailiac skinfold were significantly greater in family members of patients with breast cancer compared with controls.

CONCLUSIONS

A marked variation occurred in body fat localization among first-degree relatives of patients with breast cancer and in cancer-free families. This finding implies a variation in breast cancer risk in these families. Identifying family members with upper body fat distribution in breast cancer families would allow targeting of these individuals for energetic screening and risk factor reduction interventions.

Selection criteria for breast cancer chemoprevention subjects

Early phase chemoprevention trials differ from standard therapeutic clinical trials because asymptomatic, healthy people are treated with a potentially toxic intervention for a prolonged period of time. Current subject selection protocols have relied upon epidemiological methods to identify high-risk individuals. Most available data provide risk estimates for various individual risk factors, but few have reported risk estimates for combinations of risk factors. Selection criteria for the large tamoxifen intervention trial (NSABP P1) were developed from the work of Gail et al. [1]. The Gail model takes into account non-genetic factors (e.g., nulliparity, age at menarche, preexisting pathological conditions) and genetic factors (family history). Using a lifetime risk of 10% of developing breast cancer as a standard to intervene, NSABP P1 uses the Gail algorithm to select pre- and postmenopausal women for a primary intervention trial. This approach has been criticized for being insufficiently selective (i.e., all women > or = 60 yrs), but appears to be the best available method to select subjects for a chemoprevention trial. Other approaches have been based on identification of very high-risk women with acknowledged pathologic conditions [lobular carcinoma in situ, ductal carcinoma in situ (DCIS)]. Attempting to use these proliferative lesions as pathologic endpoints for drug effect has not been attempted. DCIS as a risk factor for tamoxifen intervention was excluded because of controversies over its management and because of frequent difficulties in distinguishing microinvasive from non-invasive lesions. Women treated for early stage breast cancer (Stage I) may be subjects for early stage chemopreventive interventions.(ABSTRACT TRUNCATED AT 250 WORDS)

Height and weight at various ages and risk of breast cancer

A study of 1529 breast cancer patients and 1901 control subjects enabled evaluation of risk in relation to lifetime changes in body size. Tallness, regardless of when achieved, was associated with an increased risk of breast cancer diagnosed at both young (< 50 years) and older ages, with adult height of 68 in or more increasing risk by nearly 50 to 80% compared with statures of less than 62 in. The association of risk with weight was less clear. Subjects who described themselves as heavier than average at ages 8 to 9 or 16 years were at reduced risk, particularly for older-onset breast cancer. Higher body mass indices based on reported weights during early adulthood were also associated with reduced risk. Measures of body mass beyond the age of 20, however, were less strongly related to risk. These inconsistent patterns appeared to be explained by an effect on risk of weight gain later in life, which was related to reduced risks for young-onset breast cancer and increased risks for later disease. The effect of weight change for early-onset breast cancer was not restricted to in situ cancers and could therefore not be attributed to detection bias. The direct relationship of body mass change with older onset disease was restricted to invasive cancers, consistent with observations of poor breast cancer prognosis among obese women. Further attention on the relationship of anthropometric variables to risk of breast cancer should focus on the timing of weight gain as well as the distribution of body fat.