Body weight and prognostic indicators in breast cancer. Modifying effect of estrogen receptors

The Effect of Body Mass Index on Initial Breast Cancer Stage Among Korean Women

BACKGROUND

The relationship between obesity and breast cancer stage is not well-known in the Korean population. This study aimed to identify the effect of body mass index (BMI) on initial breast cancer stage.

PATIENTS AND METHODS

Among patients who underwent surgery for breast cancer (stages 0-III) from June 2003 to December 2018, we analyzed 4510 patients for whom there were BMI data.

RESULTS

The average BMI of our patients was 23.5 (14.2-44.9). In total, 4.6% and 24.2% of the patients had a BMI of ≥30 and 25-29.9, respectively. In the patients with obesity, the proportion of T2 to T4 was 41.4%, which was higher than that in patients with a BMI of 25 to 29 (28.4%; P = .001) or a BMI of <25 (23.3%; P < .001). There was no difference in positive rates of estrogen receptor and progesterone receptor with BMI, but obese patients were less likely to be human epidermal growth factor receptor 2 positive. Patients with higher stages were more likely to have a higher BMI. The effect of BMI on stage was stronger in patients <50 years (odds ratio, 2.439; 95% CI, 1.783-3.335). Although there was no statistical significance, tumors >2 cm were less likely to be palpable in obese patients than in patients of normal weight (nonpalpable in 33.8% and 27.0%, respectively).

CONCLUSION

Our study suggests that obesity is associated with a more advanced breast cancer stage, which represents a poor prognosis, and large tumors tend to be less palpable in women with obesity.

Overweight: Is It a Prognostic Factor in Women with Triple-Negative Breast Cancer?

Background:

Obesity is associated with poor outcomes in patients with breast cancer expressing hormone receptors, but this association is not well established for triple-negative breast cancer. In this study, we investigated the influence of body mass index (BMI) in triple-negative breast cancer outcomes.

Methods:

This is a descriptive and analytical retrospective cohort study at the Regional Oncology Center Hassan II-Oujda. We identified 115 patients with triple-negative breast cancer, met the criteria for inclusion, treated between January 2009 and December 2011. The clinicopathological characteristics were collected to assess the association between BMI and overall survival and disease-free survival at 5 years, using the Kaplan-Meier and Cox model.

Results:

Data analysis focused on 115 patients, 34 patients (28.7%) were normal weight (BMI < 25) and 82 patients (71.3%) were overweight (BMI ≥ 25). The rates of overall mortality and progression at 5 years were 37.4% and 69.6% respectively. After adjusting for clinicopathological variables and menopausal status, overweight was associated with OS (HR: 2.903, 95% CI: 1.551- 5.432, p = 0.001) and DFS (HR: 1.899, 95% IC: 1.05 – 3.433, p=0.034) in all patients with triple-negative breast cancer. When stratified by menopausal status, overweight was associated with DFS and OS (HR: 3.242, 95% CI: 1.249 to 8.412, p = 0.016) and (HR: 2.752, 95% CI: 1.267 to 5.978, p = 0.011) respectively in pre-menopausal women. By cons, BMI was not associated with DFS or OS in postmenopausal women.

Conclusions:

Overweight is an independent prognostic factor for OS and DFS at 5 years in all patients with triple-negative breast cancer, and menopausal status may be a mitigating factor. Premenopausal women with overweight are at greater risk of death and progression than women with normal weight. Once validated, these results should be considered in the development of prevention programs.

Obesity and breast cancer: status of leptin and adiponectin in pathological processes

It is well recognized that obesity increases the risk of various cancers, including breast malignancies in postmenopausal women. Furthermore, obesity may adversely affect tumor progression, metastasis, and overall prognosis in both pre- and postmenopausal women with breast cancer. However, the precise mechanism(s) through which obesity acts is/are still elusive and this relationship has been the subject of much investigation and speculation. Recently, adipose tissue and its associated cytokine-like proteins, adipokines, particularly leptin and adiponectin, have been investigated as mediators for the association of obesity with breast cancer. Higher circulating levels of leptin found in obese subjects could be a growth-enhancing factor as supported by in vitro and preclinical studies, whereas low adiponectin levels in obese women may be permissive for leptin's growth-promoting effects. These speculations are supported by in vitro studies which indicate that leptin promotes human breast cancer cell proliferation while adiponectin exhibits anti-proliferative actions. Further, estrogen and its receptors have a definite impact on the response of human breast cancer cell lines to leptin and adiponectin. More in-depth studies are needed to provide additional and precise links between the in vivo development of breast cancer and the balance of adiponectin and leptin.

Effects of dietary fat on spontaneous metastasis of Lewis lung carcinoma in mice

The present study assessed the effects of dietary fat on spontaneous metastasis of Lewis lung carcinoma in mice. Three-week old male C57BL/6 mice were fed the AIN-93G diet or a 45% fat diet (% kcal.) for 7 weeks before they were subcutaneously injected with 2.5 × 10⁵ viable carcinoma cells. The primary tumor was resected 2 weeks later, and mice were maintained on their respective diets for an additional 2 weeks. The high-fat diet significantly increased body weight and abdominal adipose weight compared to the AIN-93G diet. Feeding mice the 45% fat diet resulted in a two-fold increase in the number of lung metastases (P < 0.05), a 35% increase in tumor cross-sectional area, and a 50% increase in tumor volume compared to mice fed the AIN-93G diet. There were no differences in plasma concentrations of TIMP-1, IL-1β, VEGF and MCP-1 in non-tumor-bearing mice fed the AIN-93G diet or the high-fat diet, but significant increases in these cytokines in tumor-bearing mice fed the AIN-93G diet compared to the non-tumor-bearing mice fed the same diet (P < 0.05 for each comparison). Further significant increases in these cytokines in tumor-bearing mice fed the 45% fat diet compared to the same tumor-bearing mice fed the AIN-93G diet (P < 0.05 for each comparison). The high-fat diet significantly increased plasma leptin and significantly decreased plasma adiponectin compared to the AIN-93G diet in both non-tumor-bearing and tumor-bearing mice. Results of the present study demonstrated that the high-fat diet enhanced spontaneous metastasis of Lewis lung carcinoma in mice and that this aggressiveness was accompanied with significant increases in plasma concentrations of angiogenic cytokines, suggesting that dietary fat affects metastasis by promoting angiogenic processes.

The contribution of dynamic stromal remodeling during mammary development to breast carcinogenesis

Breast cancer is a heterogeneous disease whose prognosis varies depending upon the developmental stage of the breast tissue at diagnosis. Notably, breast cancers associated with pregnancy exhibit increased rates of metastasis and poorer long-term survival compared to those diagnosed after menopause. However, postmenopausal breast cancers associated with obesity exhibit a more aggressive behavior and confer decreased overall patient survival compared to those diagnosed in non-obese individuals. Since the mammary gland is a dynamic tissue that undergoes significant changes throughout a woman's lifetime, especially during pregnancy and following menopause, we present evidence to support the notion that changes occurring throughout development within the mammary stromal compartment may account for some of the biological differences in breast cancer subtypes and behaviors.

Effect of body mass index on recurrences in tamoxifen and anastrozole treated women: an exploratory analysis from the ATAC trial

PURPOSE

Third-generation aromatase inhibitors have been widely used in postmenopausal women for the adjuvant treatment of hormone receptor-positive breast cancer. As aromatase inhibitors work by inhibiting the conversion of androgens to estrogens in adipose tissue, we hypothesized that anastrozole may be more effective in women with a high body mass index (BMI).

PATIENTS AND METHODS

The Arimidex, Tamoxifen Alone or in Combination (ATAC) study was a double-blind randomized clinical trial in which postmenopausal women with early-stage breast cancer were randomly assigned to receive oral daily anastrozole (1 mg) alone, tamoxifen (20 mg) alone, or the combination in a double-blind fashion. Analyses were based on the 100-month median follow-up for women with hormone receptor-positive breast cancers (estrogen [ER] and/or progesterone [PgR] positive). Here, we investigate the impact of BMI on recurrence and the relative benefit of anastrozole versus tamoxifen according to baseline BMI. Results Overall, women with a high BMI (BMI > 35 kg/m(2)) at baseline had more recurrences than those women with a low BMI (BMI < 23 kg/m(2); adjusted hazard ratio [HR], 1.39; 95% CI, 1.06 to 1.82; P(heterogeneity) = .03) and significantly more distant recurrences (adjusted HR, 1.46; 95% CI, 1.07 to 1.61; P(heterogeneity) = .01). Overall, the relative benefit of anastrozole versus tamoxifen was nonsignificantly better in thin women compared to overweight women.

CONCLUSION

These results confirm the poorer prognosis of obese women with early-stage breast cancer. Recurrence rates were lower for anastrozole than tamoxifen for all BMI quintiles. Our results suggest that the relative efficacy of anastrozole compared to tamoxifen is greater in thin postmenopausal women and higher doses or more complete inhibitors might be more effective in overweight women, but this requires independent confirmation.

Impact of obesity on diagnosis and treatment of breast cancer

In this population-based study, we evaluated the impact of obesity on presentation, diagnosis and treatment of breast cancer. Among all women diagnosed with invasive breast cancer in the canton Geneva (Switzerland) between 2003 and 2005, we identified those with information on body mass index (BMI) and categorized them into normal/underweight (BMI <25 kg/m(2)), overweight (BMI > or =-<30 kg/m(2)) and obese (BMI > or =30 kg/m(2)) women. Using multivariate logistic regression, we compared tumour, diagnosis and treatment characteristics between groups. Obese women presented significantly more often with stage III-IV disease (adjusted odds ratio [OR(adj)]: 1.8, 95% CI: 1.0-3.3). Tumours > or =1 cm and pN2-N3 lymph nodes were significantly more often impalpable in obese than in normal/underweight patients (OR(adj) 2.4, [1.1-5.3] and OR(adj) 5.1, [1.0-25.4], respectively). Obese women were less likely to have undergone ultrasound (OR(adj) 0.5, [0.3-0.9]) and MRI (OR(adj) 0.3, [0.1-0.6]) and were at increased risk of prolonged hospital stay (OR(adj) 4.7, [2.0-10.9]). This study finds important diagnostic and therapeutic differences between obese and lean women, which may impair survival of obese women with breast cancer. Specific strategies are needed to optimize the care of obese women with or at risk of breast cancer.

Leptin utilizes Jun N-terminal kinases to stimulate the invasion of MCF-7 breast cancer cells

In breast tumors, high levels of leptin have been associated with increased incidence of breast cancer metastasis. Breast cancer metastasis is directly associated with breast cancer cell invasion. However, whether leptin could augment breast cancer cell invasion is not known. Here we showed that leptin increased the invasiveness and the matrix metallo-proteinase-2 (MMP-2) activity of the MCF-7 breast cancer cell line. Leptin stimulated the phosphorylation of extracellular signals regulated kinases, signal transducers and activators of transcription 3 and Jun N-terminal kinases (JNK); however, only inhibition of JNK decreased leptin-mediated activation of MMP-2. Furthermore, inhibition of JNK suppressed leptin-mediated breast cancer cell invasion. Here we report the novel findings that leptin increased invasion of breast cancer cells by activating JNK, resulting in increased MMP-2 activity.

Availability and utility of body mass index for population-based cancer surveillance

OBJECTIVE

To evaluate the availability of body height and weight data in the hospital medical record of cancer patients and discuss the utility of the findings to population-based cancer research and the surveillance of overweight and obesity in the United States.

METHODS

Medical records were reviewed for up to three measures of height and weight for a random sample of 1,739 patients diagnosed (2001-2003) with one of the 12 types of cancer and reported to the population-based Greater Bay Area Cancer Registry of Northern California.

RESULTS

About 84% of cancer patients had at least one value of height, 91% had at least one value of weight, and 83% had both values recorded in the medical record such that body mass index (BMI) could be computed. About 60% of height and weight values were recorded within 2 months of cancer diagnosis, with most values (71%) recorded after cancer diagnosis. The availability of BMI varied somewhat by race/ethnicity, cancer site, initial treatment, and hospital characteristics.

CONCLUSIONS

BMI may be sufficiently available to be included routinely in the population-based cancer registries, and, if so, would be useful for studies of cancer diagnoses and outcomes and permit nationwide surveillance of BMI in a large population-representative cohort of cancer patients.

Is obesity an independent prognosis factor in woman breast cancer?

BACKGROUND

Breast cancer and obesity represent important public health issues in most western countries. A number of studies found a negative prognosis effect of obesity or excess of weight in woman breast cancer. However, to date, this issue remains controversial. The objectives of this study were to confirm the prognosis role of obesity on a large cohort of patients and to investigate a potential independent effect.

MATERIALS AND METHODS

We constituted a cohort of 14,709 patients who were recruited and treated at the Curie Institute (Paris) from 1981 to 1999. These patients were followed prospectively for a first unilateral invasive breast cancer without distant metastasis. Obesity was defined by a Body Mass Index (BMI) above 30 kg/m(2) according to the World Health Organization recommendations.

RESULTS

Obese patients (8%) presented more extended tumors at diagnosis time suggesting a delayed breast cancer diagnosis. However, obesity appeared as a negative prognosis factor for several events in respectively univariate and multivariate survival analysis: metastasis recurrence (HR = 1.32[1.19-1.48]; HR = 1.12[1.00-1.26]), disease free interval (1.20[1.08-1.32]; 1.10[0.99-1.22]), overall survival (1.43[1.28-1.60]; 1.12[0.99-1.25]) and second primary cancer outcome (1.57[1.19-2.07]; 1.43[1.09-1.89]). Even if obese patients presented more advanced tumors at diagnosis time, multivariate analysis showed that there was a relevant independent effect. Other BMI codings, distinguishing overweight patients or using BMI as a continuous variable, showed a consistent correlation between BMI's value and prognosis effect. Interaction analysis revealed a more important obesity effect in the presence of tumor estrogen receptors and among limited extent tumors.

CONCLUSIONS

This survey confirms the prognosis role of obesity on one of the largest cohort by investigating several prognosis events. While independent obesity effect linked to hormonal disorders appeared consistent as obesity's mechanism, we stress that obesity prognosis effect was also related to breast cancer presentation at diagnosis time.

Combination of physical activity, nutrition, or other metabolic factors and vaccine response

A number of lifestyle factors that reduce cancer risk in the primary prevention setting may be potential new targets for use in combination with cancer vaccines. This review discusses the modulation of energy balance (physical activity, calorie restriction, and obesity prevention), and the supplementation with natural and synthetic analogs of vitamins A and E, as potential interventions for use in combination with cancer vaccines. Additionally, the pharmacologic manipulation of nutrient metabolism in the tumor microenvironment (e.g., arachidonic acid, arginine, tryptophan, and glucose metabolism) is discussed. This review includes a brief overview of the role of each agent in primary cancer prevention; outlines the effects of these agents on immune function, specifically adaptive and/or anti-tumor immune mechanisms, when known; and discusses the potential use of these interventions in combination with therapeutic cancer vaccines. Modulation of energy balance through exercise and strategies targeting nutrient metabolism in the tumor microenvironment represent the most promising interventions to partner with therapeutic cancer vaccines. Additionally, the use of vitamin E succinate and the retinoid X receptor-directed rexinoids in combination with cancer vaccines offer promise. In summary, a number of energy balance- and nutrition-related interventions are viable candidates for further study in combination with cancer vaccines.

Body mass index and mortality among older breast cancer survivors in the Study of Osteoporotic Fractures

BACKGROUND

Breast cancer survival is inversely related to body mass index (BMI), but previous studies have not included large numbers of older women. This study investigated the association between BMI and mortality after breast cancer diagnosis in a cohort of older Caucasian women enrolled in the Study of Osteoporotic Fractures.

METHODS

All women were age >or=65 at study entry (N = 533). Cox proportional hazards regression analysis was used to determine the effect of BMI as a continuous variable on risk of all-cause, cardiovascular, any cancer, and breast cancer mortality. Interaction terms were included to evaluate effect modification by age at diagnosis.

RESULTS

Mean age at diagnosis was 78.0 years (SD 5.7) with an average of 8.1 years (SD 4.4) of follow-up after diagnosis. There were 206 deaths during follow-up. The effect of BMI on mortality depended on age (P(interaction) = 0.02). At age 65, the risk of mortality was 1.4 times higher for a BMI of 27.3 kg/m(2) [95% confidence interval (95% CI), 1.03-2.01] and 2.4 times higher for a BMI of 34.0 kg/m2 (95% CI, 1.07-5.45) compared with women with a BMI of 22.6 kg/m2. At age 85, risk of death was lower for a BMI of 27.3 kg/m2 (hazard ratio, 0.81; 95% CI, 0.65-1.01) or a BMI of 34.0 kg/m2 (hazard ratio, 0.61; 95% CI, 0.36-1.02) compared with a BMI of 22.6 kg/m2. Similar results were observed for any cancer and breast cancer mortality. BMI was not associated with cardiovascular mortality.

CONCLUSIONS

In this population of older women, the effect of increased BMI on risk of mortality after breast cancer varied by age. These results differ from those observed among populations of younger postmenopausal breast cancer survivors.

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.

Health behaviors and breast cancer: experiences of urban African American women

Breast-cancer survival rates are lower among African American women compared to White women. Obesity may contribute to this disparity. More than 77% of African American women are overweight or obese. Adopting health behaviors that promote a healthy weight status may be beneficial because obesity increases risk for recurrence. Studies among White breast-cancer survivors indicate that many make health behavior changes after diagnosis. This cross-sectional pilot study collected quantitative and qualitative data on the attitudes, beliefs, barriers, and facilitators related to health behavior changes in 27 overweight/obese African American breast-cancer survivors. Results indicated that most participants reported making dietary changes since their diagnosis, and some had increased their physical activity. Focus groups provided rich details on the barriers and facilitators for behavior change. These results begin to address the significant gap in our knowledge of African American breast-cancer survivors' health behaviors and underscore the need for culturally competent health behavior interventions.

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.

Effects of obesity and race on prognosis in lymph node-negative, estrogen receptor-negative breast cancer

BACKGROUND

Several factors may contribute to poorer prognosis for obese breast cancer patients, including unfavorable disease features, the influence of fat on estrogen availability, co-morbidity, and socio-demographic factors. Both obesity and estrogen receptor negative (ER-) tumors are more prevalent in black women than in whites in North America. We evaluated obesity and race in relation to outcomes in women with ER-breast cancer.

METHODS

Among 4,077 women from National Surgical Adjuvant Breast and Bowel Project clinical trials for node-negative, ER-breast cancer, we evaluated disease-free survival (DFS) and its constituents (tumor recurrence, contralateral breast cancer (CBC), second primary cancers, deaths prior to these events) and mortality in relation to body mass index (BMI) and race, using statistical modeling to account for other prognostic factors.

RESULTS

Compared to those of normal weight (BMI< or =24.9), DFS hazard was greater for obese (BMI > or = 30) women [hazard ratio (HR)=1.16, 95% confidence interval (CI)=1.01-1.33]. Obesity did not increase recurrence hazard, but did influence CBC (HR=2.08, 95% CI=1.22-3.55 in postmenopausal women) and second cancers (HR=1.49, 95% CI=1.06-2.10). Mortality increased with obesity; when partitioned by likely cause, those with BMI > or = 35.0 had greater risk of non-breast cancer mortality (HR=1.86, 95% CI=1.21-2.84). Relative to whites and adjusted for BMI, black women had greater hazard for DFS (HR=1.17, 95% CI=1.00-1.38), CBC (HR=1.37, 95% CI=0.94-1.99), and non-breast cancer deaths (HR=2.10, 95% CI=1.45-3.03); risk for deaths likely due to breast cancer was closer to that in whites (HR=1.18; 95% CI=0.93-1.50).

CONCLUSIONS

For women with node-negative, ER-breast cancer from clinical trials, obesity did not increase recurrence risk, but was associated with greater risk for second cancers, CBC, and mortality, particularly non-breast cancer deaths. Less favorable prognosis for black women persists in clinical trials, and is in part attributable to non-breast cancer outcomes.

Body mass and mortality after breast cancer diagnosis

Obesity is an established risk factor for some breast cancers, but less is known about its effect on breast cancer prognosis. Understanding this relationship is important, given the increasing number of women diagnosed with breast cancer and the growing prevalence of obesity. We conducted a cohort analysis of 3,924 women ages 20 to 54 with incident breast cancer enrolled between 1980 and 1982 in the Cancer and Steroid Hormone study, a case-control study. Interview data were linked to survival information from the Surveillance, Epidemiology, and End Results Program. We used proportional hazards models to examine the relationship between breast cancer mortality and adult body mass index (BMI; calculated using usual adult weight), BMI at age 18, and weight change from age 18 to adulthood. Hazard ratios (HR) were adjusted for cancer stage and other factors. During a median follow-up of 14.6 years, 1,347 women died of breast cancer. Obese women (adult BMI>or=30.00) were significantly more likely than lean women (BMI<or=22.99) to die of breast cancer [HR, 1.34; 95% confidence interval (CI), 1.09-1.65]. Women with BMIs of 25.00-29.99 (HR, 1.25; 95% CI, 1.08-1.44) or 23.00-24.99 (HR, 1.20; 95% CI, 1.04-1.39) also had higher breast cancer mortality (P for trend <0.0001). BMI at age 18 and weight change were not associated with breast cancer mortality independently of other factors. Obesity could be a preventable risk factor for death among breast cancer patients. Further study is needed to determine how these findings might affect recommendations to reduce breast cancer mortality.

The associations of obesity, lymph node status and prognosis in breast cancer patients: dependence on estrogen and progesterone receptor status

Breast cancer patients who are obese have a higher risk of lymph node metastases and a poorer prognosis than those who are slim. It has been claimed that estrogens derived from fat are important for these associations. If estrogens are important, these relationships must be stronger in the hormone receptor-positive than in the hormone receptor-negative groups. Body mass index (BMI) was used as a measure of obesity. The second, third, and fourth quintiles of BMI were treated as one group and termed 'medium'. Patients in the fifth quintile were termed 'obese' and those in the first quintile 'slim'. The number of women with unilateral disease treated with modified radical mastectomy and included in the study was 1211. Of all patients included, obese patients had a 1.53 higher risk of lymph node metastases compared to slim patients (p=0.02). In the PgR-negative group, obesity gave a 3.08 times higher risk of lymph node metastases (p=0.03). The risk of dying of breast cancer tended to be higher in obese than in slim patients when all patients in the study were compared (relative risk=1.38, p=0.06). BMI did not show a statistically significant relationship with prognosis if only hormone receptor status was considered. However, if lymph node status and hormone receptor status were taken together, the association was strong and reversed in the lymph node-positive group with ER-negative tumours. The adjusted relative risk was 0.33, showing that slim patients had a 3.03 (1.0/0.33) times higher risk of dying of breast cancer compared to obese patients (p=0.002). These results indicate that non-hormonal mechanisms could be important.

Diet-Induced Obesity and Mammary Tumor Development in MMTV-neu Female Mice

Obesity is a risk factor for postmenopausal breast cancer and is associated with shortened latency and/or increased mammary tumor (MT) incidence in animals. Elevated body weight is usually associated with hormone-responsive tumors. In agreement with these data we previously showed that latency of hormone-responsive MTs in MMTV-TGF-alpha mice with diet-induced obesity was significantly shortened. Here, we used the same protocol to determine the impact of diet-induced obesity on estrogen receptor-negative MT development in MMTV-neu (strain 202) mice. Mice were fed a low-fat diet (n=20) or a high-fat diet (n=54) from 10 wk of age. Body weight at 19 wk of age was used to assign high-fat mice to obesity-prone, overweight, and obesity-resistant groups. Mice were euthanized due to MT size or at 85 wk of age. Final body weights of obesity-prone mice were heaviest, and those of obesity-resistant and low-fat groups were similar. Fat pad weights were heaviest in obesity-prone mice followed by overweight and obesity-resistant groups, and lightest in low-fat mice. Serum IGF-I levels were similar for low-fat and high-fat mice, whereas leptin was higher in high-fat mice (P <0.0001). MT latency, incidence, metastasis, and burden were similar for all groups. These findings support that obesity is not a risk factor for development of estrogen-negative breast cancer.

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, tamoxifen use, and outcomes in women with estrogen receptor-positive early-stage breast cancer

BACKGROUND

Obesity is associated with both increased breast cancer risk and poorer prognosis after disease onset. However, little is known about the effect of obesity on treatment efficacy. We evaluated the association of obesity with outcomes and with tamoxifen efficacy in women with early-stage, hormone-responsive breast cancer participating in a multicenter cancer cooperative group clinical trial.

METHODS

The cohort consisted of 3385 women enrolled in National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-14, a randomized, placebo-controlled trial evaluating tamoxifen for lymph node-negative, estrogen receptor (ER)-positive breast cancer. Hazards of breast cancer recurrence, contralateral breast tumors, other new primary cancers, and several mortality endpoints were evaluated in relation to body mass index (BMI), using statistical modeling to adjust for other prognostic factors. Median follow-up time was 166 months. All statistical tests were two-sided.

RESULTS

The hazard of breast cancer recurrence was the same among obese (BMI > or =30.0 kg/m2) women as compared with underweight and normal-weight women (BMI <25.0; hazard ratio [HR] = 0.98, 95% confidence interval [CI] = 0.80 to 1.18). Contralateral breast cancer hazard was higher in obese women than in underweight/normal-weight women (HR = 1.58, 95% CI = 1.10 to 2.25), as was the risk of other primary cancers (HR = 1.62, 95% CI = 1.16 to 2.24). Compared with normal-weight women, obese women had greater all-cause mortality (HR = 1.31, 95% CI = 1.12 to 1.54) and greater risk of deaths due to causes unrelated to breast cancer (HR = 1.49, 95% CI = 1.15 to 1.92). Breast cancer mortality was not statistically significantly increased for obese women (HR = 1.20, 95% CI = 0.97 to 1.49). Tamoxifen reduced breast cancer recurrence and mortality, regardless of BMI.

CONCLUSIONS

For women with lymph node-negative, ER-positive breast cancer, obesity was not associated with a material increase in recurrence risk or a change in tamoxifen efficacy. However, because obesity was associated with increased risks of contralateral breast cancer, of other primary cancers, and of overall mortality, it may influence long-term outcomes for breast cancer survivors.

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.

Premorbid body weight and its relations to primary tumour diameter in breast cancer patients; its dependence on estrogen and progesteron receptor status

Hormonal mechanisms have been offered as an explanation for the higher frequency of large tumours, lymph node metastases and poorer prognosis in obese breast cancer patients than in lean ones. If hormonal mechanisms are important for these relations, they should probably act more strongly in patients with hormonal receptor positive tumours than in those with negative ones. We have examined if the relations between premorbid body weight or Quetelet's index (weight/height2) and tumour diameter are modified by estrogen receptor alpha (ER) and progesteron receptor (PgR) status. The analyses were based on 1,241 women with unilateral disease treated with modified radical mastectomy living in the geografic area of Haukeland Hospital. Their body weight and height have been measured as a mean 12.5 years before presentation of the disease. Body weight and Quetelet's index have been adjusted for age. The relations were studied using linear regression analyses adjusting the effect of body weight with height and mean nuclear area of the tumour cells and adjusting the effect of Quetelet's index for mean nuclear area. The main findings showed that patients with high body weight or Quetelet's index presented more often with PgR positive tumours than lean ones. Quetelet's index was also positively related to ER. These relations were present in patients older than 50 years of age (older). Patients with large tumours (>2.0 cm) had significantly higher body weight and Quetelet's index than those with small ones. These differences were significantly present in older patients and in patients with PgR negative and ER negative-PgR negative tumours. Linear regression analyses confirmed that tumour diameter increases with body weight and Quetelet's index. These relations were present in both lymph node groups and in older patients. Stratification according to hormonal receptor status showed these relations to be significant in patients with ER negative, with PgR negative and those with ER negative-PgR negative tumours only. Taking age and hormonal receptor status into consideration simultaneously, both body weight and Quetelet's index were significantly related to tumour diameter in older patients with hormone receptor negative tumours. In conclusion body size was positively related to hormone receptor status and to diameter of the primary tumour. The relation to tumour diameter was present in older patients with hormone receptor negative tumours. Although hormonal mechanisms able to act on the tumour can not be excluded, mechanisms acting independent of hormonal receptors must be considered. Different mechanisms related to body fat cytokines are discussed.

Stressful life events and survival after breast cancer

OBJECTIVE

This study assessed the relation of stressful life events with survival after breast cancer.

METHODS

This study was based on women with histologically confirmed, newly diagnosed, localized or regional stage breast cancer first treated in 1 of 11 Quebec City (Canada) hospitals from 1982 through 1984. Among 765 eligible patients, 673 (88%) were interviewed 3 to 6 months after diagnosis about the number and perceived impact of stressful events in the 5 years before diagnosis. Three scores were calculated: number of events; number weighted by reported impact; and for almost 80% of events, number weighted by community-derived values reflecting adjustment required by the event. Scores were divided into quartiles to assess possible dose-response relationships. Survival was assessed in 1993. Hazard ratios and 95% confidence intervals (CIs) comparing all-cause and breast cancer-specific mortality were calculated with adjustment for age, presence of invaded axillary nodes, adjuvant radiotherapy, and systemic therapy (ie, chemotherapy and hormone therapy).

RESULTS

When quartiles 2, 3, and 4 were compared with the appropriate lowest quartile, adjusted hazard ratios for all-cause mortality were 0.99 (CI = 0.70-1.38), 0.97 (CI = 0.73-1.31), and 1.04 (CI = 0.78-1.40) for number, number weighted by impact, and number weighted by community-derived values, respectively. Results were essentially similar for the relation between stressful life events limited to those occurring within the 12 months before diagnosis and overall mortality and between stressful life events in the 5 years before diagnosis and breast cancer-specific mortality.

CONCLUSIONS

Stress was conceptualized as life events presumed to be negative, undesirable, or to require adjustment by the person confronting them. We found no evidence indicating that this kind of stress during the 5 years before diagnosis negatively affected survival among women with nonmetastatic breast cancer. Evidence from this study and others on the lack of effect of this type of stress on survival may be reassuring for women living with breast cancer.

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.

Android obesity at diagnosis and breast carcinoma survival: Evaluation of the effects of anthropometric variables at diagnosis, including body composition and body fat distribution and weight gain during life span,and survival from breast carcinoma

BACKGROUND

Although a large body of research exists concerning pathologic prognostic indicators of the rate of incidence and survival from breast carcinoma, to the authors' knowledge very few studies have examined the effects of anthropometric variables such as height, obesity, weight gain in adulthood, timing of weight gain, and body composition to survival, although these variables are related to the incidence rate.

METHODS

The survival status of 166 patients diagnosed with primary breast carcinoma and followed for at least 10 years was obtained from the Cancer Center's registry, and significant anthropometric and other known prognostic indicators regarding survival after diagnosis were determined by Cox proportional hazards analysis.

RESULTS

Eighty-three of 166 breast carcinoma patients (50%) with up to 10 years of follow-up died of disease. Android body fat distribution, as indicated by a higher suprailiac:thigh ratio, was a statistically significant (P < 0.0001) prognostic indicator for survival after controlling for stage of disease, with a hazards ratio of 2.6 (95% confidence interval [95% CI], 1.63-4.17). Adult weight gain, as indicated specifically by weight at age 30 years, was a statistically significant (P < 0.05) prognostic indicator for survival with a hazards ratio of 1.15 (95% CI, 1.0-1.28). In addition, the authors observed the Quatelet Index, a negatively significant (P < 0.01) prognostic indicator for survival with a hazards ratio of 0.92 (95% CI, 0.87-0.98). Other markers of general obesity such as weight at diagnosis, percent body fat, and body surface area were not significant markers influencing survival. Similarly, height; triceps, biceps; subscapular, suprailiac, abdominal, and thigh skinfolds; waist and hip circumferences; family history; and reproductive and hormonal variables at the time of diagnosis showed no apparent significant relation to survival.

CONCLUSIONS

The results of the current study provide some evidence that android body fat distribution at diagnosis and increased weight at age 30 years increases a woman's risk of dying of breast carcinoma.

Screening for cervical and breast cancer: is obesity an unrecognized barrier to preventive care?

BACKGROUND

Compared with thinner women, obese women have higher mortality rates for breast and cervical cancer. In addition, obesity leads to adverse social and psychological consequences. Whether obesity limits access to screening for breast and cervical cancer is unclear.

OBJECTIVE

To examine the relation between obesity and screening with Papanicolaou (Pap) smears and mammography.

DESIGN

Population-based survey.

SETTING

United States.

PARTICIPANTS

11 435 women who responded to the "Year 2000 Supplement" of the 1994 National Health Interview Survey.

MEASUREMENTS

Screening with Pap smears and mammography was assessed by questionnaire.

RESULTS

In women 18 to 75 years of age who had not previously undergone hysterectomy (n = 8394), fewer overweight women (78%) and obese women (78%) than normal-weight women (84%) had had Pap smears in the previous 3 years (P < 0.001). After adjustment for sociodemographic information, insurance and access to care, illness burden, and provider specialty, rate differences for screening with Pap smears were still seen among overweight (-3.5% [95% CI, -5.9% to -1.1%]) and obese women (-5.3% [CI, -8.0% to -2.6%]). In women 50 to 75 years of age (n = 3502), fewer overweight women (64%) and obese women (62%) than normal-weight women (68%) had had mammography in the previous 2 years (P < 0.002). After adjustment, rate differences were -2.8% (CI, -6.7% to 0.9%) for overweight women and -5.4% (CI, -10.8% to -0.1%) for obese women.

CONCLUSIONS

Overweight and obese women were less likely to be screened for cervical and breast cancer with Pap smears and mammography, even after adjustment for other known barriers to care. Because overweight and obese women have higher mortality rates for cervical and breast cancer, they should be targeted for increased screening.

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.

Nutritional determinants of survival among patients with breast cancer

Recent data leave little doubt that nutritional factors modulate the growth of breast cancer cells. Nonetheless, the question of what type of diet is best for patients with a history of early-stage breast cancer or for patients with metastatic breast cancer continues to loom despite a growing number of studies on nutrition and cancer. Recommendations for the general population from the American Cancer Society and the Dietary Guidelines for Americans outline 25% of calories from fat, multiple servings of fruits and vegetables, and an emphasis on eating a variety of different foods. Although these recommendations likely constitute prudent advice for patients with breast cancer who have completed treatment for early-stage disease, they remain unproved. Specific, beneficial recommendations for patients currently receiving adjuvant chemotherapy or for patients with metastatic disease may well differ from those for the general population. Future clinical trials will play an important role in clarifying such issues.

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.

Obesity affects expression of progesterone receptors and node metastasis of mammary carcinomas in postmenopausal women without a family history

Possible relationships between risk factors, such as obesity and a family history of breast cancer, and prognostic factors of mammary carcinomas were investigated by examining the body mass index of patients and the expression of estrogen (ER) and progesterone receptors (PgR), c-erbB-2 and p53, grade of histology, size of tumors and nodal status of mammary carcinomas. There was no significant difference in the body mass index of premenopausal patients either with or without a family history. For postmenopausal patients, the body mass index was significantly low in patients with a family history compared with patients without a family history. In premenopausal patients with or without a family history and in postmenopausal patients with a family history, there was no significant difference in the body mass index regardless of the mammary carcinoma prognostic factor, such as expression of ER, PgR, c-erbB-2 and p53, grade of histology, size of tumors and nodal status. However, in postmenopausal patients without a family history, body mass index was significantly high for patients with mammary carcinomas that had PgR expression and node metastasis. These results suggest that obesity may affect the PgR status and nodal status of mammary carcinomas in postmenopausal patients without a family history.

Risk factors, lifetime risk, and age at onset of breast cancer

PURPOSE

We evaluated the relationship between exposure variables and both lifetime risk and mean age at diagnosis of breast cancer in subjects from the Adventist Health Study who developed breast cancer before the age of 91 years.

METHODS

Multiple decrement life-table analysis was used. This study provided data from 20,341 women followed for 6 years.

RESULTS

In the total population, 30-year-old women with a parental history of any cancer or a maternal history of breast cancer had, respectively, 72% (P < 0.002) and 98% (P < 0.03) higher lifetime risks of breast cancer. Thirty-year-old women who had their first delivery after age 24 years or body mass indices above the 50th percentile had, respectively, 53% (P < 0.007) or 57% (P = 0.01) greater lifetime risk of breast cancer. Women who exercised infrequently had a 27% higher life-time risk (P = 0.09) and an age at diagnosis of breast cancer 6.6 years younger (P < 0.005) than other women.

CONCLUSIONS

Standard risk factors account for substantial increases in lifetime risk of breast cancer and may be associated with differences in age at diagnosis.

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.

Body weight and vascular invasion in post-menopausal women with breast cancer

To examine the relationship between body weight and vascular invasion (VI) around tumours in post-menopausal women with operable breast cancer, a retrospective study was conducted of 393 patients treated in a breast unit between 1987 and 1991. Weight was measured at the time of diagnosis. Vascular invasion was recorded as being present or absent. Vascular invasion was seen in slightly more of the 50 perimenopausal patients than in the 343 post-menopausal women (44% vs 36%). In the tumour specimens from post-menopausal patients weighing <50 kg, VI was observed in 11% compared with 45% of those weighing more than 80 kg (P= 0.02). Furthermore, the 5-year survival of those with VI was 74% compared with 91% for those without (P < 0.0001). Menopausal status and body weight may influence survival in patients with breast cancer, possibly as a result of the presence of unopposed circulating oestrogens at the time of surgery. Oestrogens may alter cohesiveness of breast cancer cells and modulate secretion of proteases, thereby influencing invasive potential. Excision of tumours in such an environment may have a deleterious impact on survival.

Tumor characteristics and survival of breast cancer patients in relation to premorbid diet and body size

Nutritional factors have been suggested to play an important role in the prognosis of breast cancer through their effect on tumor characteristics. This study evaluated four tumor characteristics and prognosis in relation to premorbid diet and body size. From a cohort of 89,835 women in the National Breast Screening Study (NBSS) in Canada, data on 676 incident cases of invasive carcinoma of breast, on whom we had dietary information, were used. A high energy intake lowered the likelihood of being ER positive and PR positive but after adjusting for ER status, was still associated with a higher risk of dying of breast cancer. Total fat and various types of fats were associated with a greater likelihood that a woman would be ER and PR positive, however the likelihood of dying from breast cancer was higher with higher fat consumption. There was no significant effect of higher intakes of beta carotene or vitamin C on ER status, nodal status or tumor size, but a significantly lower risk of dying from breast cancer was observed. Higher intake of carbohydrates and calcium was associated with a lowered frequency of ER and PR positive status but also with a lower risk of dying. Of the five indicators of body size studied, higher triceps skinfold thickness was associated with a slightly lower chance of being ER positive, PR positive, and node negative, and a significantly higher likelihood of dying. It appears that while there are significant associations between some of the diet and body size variables and tumor characteristics, the effect of most nutritional factors on prognosis in breast cancer may not be mediated via their effect on tumor characteristics.

Pre-morbid body-mass-index in breast cancer: reversed effect on survival in hormone receptor negative patients

The present study consists of 1,238 women with unilateral breast cancer treated with modified radical mastectomy living in the geographic area of Haukeland Hospital. Their weight and height had been measured years before presentation of the disease. Age-adjusted Quetelet's index (weight/height2) showed that obese women had a 49% higher risk of dying from breast cancer than lean ones. The relative risk decreased slightly when adjusted for tumour diameter, lymph node status, and mean nuclear area of the tumour cells. The prognostic effect of Quetelet's index was examined according to the estrogen and/or progesterone receptor status of the tumour. In patients with a hormone receptor positive tumour, obese women had a risk that was more than three times higher than lean ones. In patients with hormone receptor negative tumour, the effect of obesity was reversed, lean patients having a risk that was more than six times higher than obese ones, even after adjustment for lymph node status, tumour diameter, and mean nuclear area. Quetelet's index, while being a prognostic variable in its own right, thus acts differently in patients with hormone receptor positive and negative tumours.

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.

The influence of excess body weight on the surgical treatment of patients with gastric cancer

Sixty-two overweight gastric cancer patients were compared with 201 normal-weight patients to clarify the influences of excessive weight on the surgical treatment of gastric cancer. The frequencies of hypertension and diabetes mellitus were significantly higher in the overweight group (P < 0.01), but no pathologic differences in the resected tumor were found between the two groups. The operative times were longer (P < 0.01) and the number of lymph nodes extirpated and examined was smaller (P < 0.01) in the overweight group. The incidence of postoperative complications was not higher in the overweight group. The postoperative survival rate of patients with nodal metastasis was statistically lower in the overweight group (P < 0.05). Regarding the causes of death in patients with nodal metastasis, 61.1% of overweight patients and 43.8% of normal-weight patients died of recurrence of gastric cancer. In conclusion, surgical treatment of overweight patients with gastric cancer was found to be technically more difficult and the prognosis of such patients with nodal metastasis may thus be worse than that of their normal-weight counterparts.

Social support and survival among women with breast cancer

BACKGROUND

Two recently reported randomized trials, one among patients with advanced breast cancer and the other among patients with early stage melanoma, suggested that social support may affect survival favorably. This study assesses relationships of social support indicators with 7-year survival among women diagnosed with localized or regional stage breast cancer.

METHODS

All newly diagnosed patients with surgically treated localized or regional disease in seven Quebec City hospitals in 1984 were considered for this analysis. Among 235 eligible patients, 224 (95%) participated in a home interview 3 months after surgery. This interview provided information on the use of confidants in the 3 months after surgery. Data on disease and treatment characteristics were abstracted from patients' medical records.

RESULTS

Compared with women who used no confidant in the 3 months after surgery, the hazard ratio for the 7-year period was 0.61 (95% confidence interval [CI], 0.33-1.12) among those who had used at least one confidant, 0.54 (95% CI, 0.28-1.06) in women who used two or more types of confidant, and 0.51 (95% CI, 0.22-1.18) among those whose confidants included either physician or nurse. These results were adjusted for age, presence of invaded axillary lymph nodes, adjuvant radiotherapy, and adjuvant systemic therapy (hormone or chemotherapy).

CONCLUSION

These results support the view that social support may be associated with longer survival among women with localized or regional stage breast cancer.

Better breast cancer survival for postmenopausal women who are less overweight and eat less fat. The Iowa Women's Health Study

BACKGROUND

The authors sought to determine whether prediagnosis obesity, body-fat distribution, and dietary intake of fats, antioxidants, and fiber may be related to survival after the diagnosis of breast cancer.

METHODS

The mortality rates of 698 postmenopausal patients with unilateral breast cancer in a large cohort study were analyzed. Body-mass index, waist-to-hip ratio, and food-frequency data were collected by questionnaire within 6 years before breast cancer was diagnosed.

RESULTS

Adjusted for age, women in the highest tertile of body mass index had a 1.9-fold higher risk (95% confidence interval = 1.0-3.7) of dying after breast cancer than those in the lowest tertile; adjusted for other prognostic variables (age, smoking, education level, extent of breast cancer, and tumor size), this relative risk was 1.5 (95% CI = 0.7 to 2.9). Waist-to-hip ratio was not related to risk of dying nor was intake of fiber or several dietary antioxidants. Independent of other prognostic variables, risk of death after breast cancer was statistically significantly elevated, with a relative risk greater than 2.0 for the highest tertiles of total fat, saturated fat, and monounsaturated fat intake, expressed as grams per day. An adjustment for energy intake, which also was associated positively with fatality, weakened these associations somewhat.

CONCLUSIONS

Although clinical trials are required, these findings support the hypothesis that a high fat intake is associated with reduced survival of postmenopausal women with breast cancer and suggest that women with breast cancer should consider limiting their intake of fat.

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.

Pre-morbid body size and the prognosis of women with breast cancer

Obesity has been associated with poor prognosis of breast cancer, but studies investigating indicators of adiposity, independent of height, such as skinfold thickness and weight/height ratio, have been limited. From a cohort of 89,835 women in the National Breast Screening Study, data on histologically confirmed, incident cases of invasive carcinoma of breast, diagnosed between January 1981 to June 1992, were analyzed. Body measurements were taken at enrollment and other risk-factor information from a self-administered questionnaire completed prior to diagnosis of the breast cancer. Mortality data were obtained by linkage to Statistics Canada, provincial cancer registries, and annual follow-up of cases through physicians. Of the 5 measures of body size studied among cases, poor prognosis was associated with higher triceps skinfold thickness only. With every 5 mm increase in skinfold, the risk of dying increased approximately 12% (relative risk, 1.12; 95% confidence intervals, 1.01 to 1.24) in the 1033 cases examined and adjusted for age at diagnosis, number of positive axillary nodes involved, and body weight. Compared with women in the lowest quartile of skinfold thickness, women in the fourth quartile had a relative risk (RR) of 1.64 (95% CI, 0.99 to 2.73). None of the other measures--weight, height, body mass index or weight/height ratio--reached any statistical significance. Since the reliability and validity of skinfold measures used in our study were never established, and no data were available for changes in body size after diagnosis, the results of this study on skinfold thickness should be used only as indicative of a need for further studies.

Alterations in estradiol metabolism in MCF-7 cells induced by treatment with indole-3-carbinol and related compounds

In mammals, estradiol (E2) metabolism primarily involves mutually exclusive hydroxylation at either C-2 or C-16 alpha. We have previously reported a consistent increase in the C-16 alpha hydroxylation activity in human breast cancer and in mouse strains with high levels of mammary tumors. Here we show that the dietary compound indole-3-carbinol (I3C) increases C-2 hydroxylation five-fold in MCF-7 cells in culture but has minimal effect on the reaction at C-16 alpha. Because I3C-induced changes in E2 metabolism result in a metabolite ratio inverse to that observed in women with breast cancer we have separately examined whether this shift conferred an anti-tumorigenic advantage to estrogen target cells. The preferential changes induced by I3C on estradiol metabolism in MCF-7 cells parallel its anti-tumorigenicity in mice. These results suggest that changes in the metabolism of estradiol via the C-2 pathway might play a significant role in decreasing risk for breast cancer in women. Indole-2-carbinol is readily available as a chemical and as a dietary component of cruciferous vegetables. Feasible dietary changes show promise of having clinical utility in the prevention of breast cancer and other hormone-dependent cancers.