Obesity at diagnosis of breast carcinoma influences duration of disease-free survival

Targeting the Tumor Microenvironment in Breast Cancer: Prognostic and Predictive Significance and Therapeutic Opportunities

Breast cancer is one of the most prevalent tumors among women. Its prognosis and treatment outcomes depend on factors related to tumor cell biology. However, recent studies have revealed the critical role of the tumor microenvironment (TME) in the development, progression, and treatment response of breast cancer. In this review, we explore the different components of the TME and their relevance as prognostic and predictive biomarkers in breast cancer. In addition, techniques for assessing the tumor microenvironment, such as immunohistochemistry or gene expression profiling, and their clinical utility in therapeutic decision-making are examined. Finally, therapeutic strategies targeting the TME are reviewed, highlighting their potential clinical benefits. Overall, this review emphasizes the importance of the TME in breast cancer and its potential as a clinical tool for better patient stratification and the design of personalized therapies.

The impact of poor metabolic health on aggressive breast cancer: adipose tissue and tumor metabolism

Obesity and type 2 diabetes are chronic metabolic diseases that impact tens to hundreds of millions of adults, especially in developed countries. Each condition is associated with an elevated risk of breast cancer and with a poor prognosis after treatment. The mechanisms connecting poor metabolic health to breast cancer are numerous and include hyperinsulinemia, inflammation, excess nutrient availability, and adipose tissue dysfunction. Here, we focus on adipose tissue, highlighting important roles for both adipocytes and fibroblasts in breast cancer progression. One potentially important mediator of adipose tissue effects on breast cancer is the fibroblast growth factor receptor (FGFR) signaling network. Among the many roles of FGFR signaling, we postulate that key mechanisms driving aggressive breast cancer include epithelial-to-mesenchymal transition and cellular metabolic reprogramming. We also pose existing questions that may help better understand breast cancer biology in people with obesity, type 2 diabetes, and poor metabolic health.

Exercise interventions on body composition and quality of life of overweight/obese breast cancer survivors: a meta-analysis

BACKGROUND

This meta-analysis aimed to assess the effects of exercise interventions on body composition and quality of life in overweight/obese breast cancer survivors.

METHODS

Eligible randomized controlled trials (RCTs) were searched from the Cochrane Library, PubMed, and Embase databases and assessed using the Cochrane Collaboration's assessing risk tool. The effect size was pooled as weighted mean difference (WMD) for body composition variables (i.e., body mass index [BMI], body fat, body weight, fat mass, lean mass, bone mineral density) and quality of life (i.e., physical health and mental health), and the confidence interval (CI) was set as 95%. Since heterogeneity existed, subgroup analysis was conducted to detect the source of heterogeneity.

RESULTS

Eight articles from six RCTs containing 548 overweight/obese breast cancer survivors (BMI ≥ 25 kg/m2) were included and analyzed. Compared to routine care, exercise intervention significantly decreased the body mass index [WMD (95% CI) = -1.37 (-2.50, -0.23) kg/m2] and body fat [WMD (95% CI) = -3.80 (-6.59, -1.01) %] of overweight/obese breast cancer survivors. Exercise intervention showed a tendency to increase physical health [WMD (95% CI) = 2.65 (-10.19, 15.48)] and mental health [WMD (95%CI) = 1.38 (-4.18, 6.95)], but no statistical significance was observed. A subgroup analysis showed the duration of intervention was a source of heterogeneity on body composition. In the 16-week subgroup, exercise intervention decreased fat mass and BMI while increased lean mass and bone mineral density. The 52-week exercise intervention was effective in increasing lean mass. A significant exercise intervention effect on reducing body fat was only detected in the 12-week subgroup.

CONCLUSION

Exercise intervention significantly decreased the body mass index and body fat of overweight/obese breast cancer survivors. The benefits of exercise interventions for overweight/obese breast cancer survivors need more evidence from high-quality RCTs with large sample sizes.

Postdiagnosis body fatness, weight change and breast cancer prognosis: Global Cancer Update Program (CUP global) systematic literature review and meta-analysis

Previous evidence on postdiagnosis body fatness and mortality after breast cancer was graded as limited-suggestive. To evaluate the evidence on body mass index (BMI), waist circumference, waist-hip-ratio and weight change in relation to breast cancer prognosis, an updated systematic review was conducted. PubMed and Embase were searched for relevant studies published up to 31 October, 2021. Random-effects meta-analyses were conducted to estimate summary relative risks (RRs). The evidence was judged by an independent Expert Panel using pre-defined grading criteria. One randomized controlled trial and 225 observational studies were reviewed (220 publications). There was strong evidence (likelihood of causality: probable) that higher postdiagnosis BMI was associated with increased all-cause mortality (64 studies, 32 507 deaths), breast cancer-specific mortality (39 studies, 14 106 deaths) and second primary breast cancer (11 studies, 5248 events). The respective summary RRs and 95% confidence intervals per 5 kg/m2 BMI were 1.07 (1.05-1.10), 1.10 (1.06-1.14) and 1.14 (1.04-1.26), with high between-study heterogeneity (I2  = 56%, 60%, 66%), but generally consistent positive associations. Positive associations were also observed for waist circumference, waist-hip-ratio and all-cause and breast cancer-specific mortality. There was limited-suggestive evidence that postdiagnosis BMI was associated with higher risk of recurrence, nonbreast cancer deaths and cardiovascular deaths. The evidence for postdiagnosis (unexplained) weight or BMI change and all outcomes was graded as limited-no conclusion. The RCT showed potential beneficial effect of intentional weight loss on disease-free-survival, but more intervention trials and well-designed observational studies in diverse populations are needed to elucidate the impact of body composition and their changes on breast cancer outcomes.

Association of Obesity With Survival Outcomes in Patients With Cancer: A Systematic Review and Meta-analysis

Importance

Obesity, defined as a body mass index (BMI) greater than 30, is associated with a significant increase in the risk of many cancers and in overall mortality. However, various studies have suggested that patients with cancer and no obesity (ie, BMI 20-25) have worse outcomes than patients with obesity.

Objective

To assess the association between obesity and outcomes after a diagnosis of cancer.

Data Sources

PubMed, the Cochrane Library, and EMBASE were searched from inception to January 2020.

Study Selection

Studies reporting prognosis of patients with obesity using standard BMI categories and cancer were included. Studies that used nonstandard BMI categories, that were limited to children, or that were limited to patients with hematological malignant neoplasms were excluded. Screening was performed independently by multiple reviewers. Among 1892 retrieved studies, 203 (17%) met inclusion criteria for initial evaluation.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were reporting guideline was followed. Data were extracted by multiple independent reviewers. Risk of death, cancer-specific mortality, and recurrence were pooled to provide an adjusted hazard ratio (HR) with a 95% CI . A random-effects model was used for the retrospective nature of studies.

Main Outcomes and Measures

The primary outcome of the study was overall survival (OS) in patients with cancer, with and without obesity. Secondary end points were cancer-specific survival (CSS) and progression-free survival (PFS) or disease-free survival (DFS). The risk of events was reported as HRs with 95% CIs, with an HR greater than 1 associated with a worse outcome among patients with obesity vs those without.

Results

A total of 203 studies with 6 320 365 participants evaluated the association of OS, CSS, and/or PFS or DFS with obesity in patients with cancer. Overall, obesity was associated with a reduced OS (HR, 1.14; 95% CI, 1.09-1.19; P < .001) and CSS (HR, 1.17; 95% CI, 1.12-1.23; P < .001). Patients were also at increased risk of recurrence (HR, 1.13; 95% CI, 1.07-1.19; P < .001). Conversely, patients with obesity and lung cancer, renal cell carcinoma, or melanoma had better survival outcomes compared with patients without obesity and the same cancer (lung: HR, 0.86; 95% CI, 0.76-0.98; P = .02; renal cell: HR, 0.74; 95% CI, 0.53-0.89; P = .02; melanoma: HR, 0.74; 95% CI, 0.57-0.96; P < .001).

Conclusions and Relevance

In this study, obesity was associated with greater mortality overall in patients with cancer. However, patients with obesity and lung cancer, renal cell carcinoma, and melanoma had a lower risk of death than patients with the same cancers without obesity. Weight-reducing strategies may represent effective measures for reducing mortality in these patients.

Pre-diagnostic aspirin use and mortality after breast cancer

BACKGROUND

Whether aspirin or other nonsteroidal anti-inflammation drug (NSAID) use is associated with mortality following breast cancer remains unclear. Consideration of use patterns and interaction with obesity may help to clarify the inconsistent results.

METHODS

Pre-diagnosis NSAID use, weight, and height were assessed ~ 3 months after diagnosis through in-person interviews with a population-based cohort of 1,442 women with first primary breast cancer. Vital status was determined through the national death index after ~ 18 years of follow-up (N = 237/597 breast cancer-specific/all-cause deaths). We used Cox proportional hazards regression to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Multiplicative interaction by body mass index (BMI) was evaluated using the likelihood ratio test.

RESULTS

Ever aspirin use was inversely associated with breast cancer-specific mortality (HR 0.87, 95% CI 0.59-1.29), but positively associated with all-cause mortality (HR 1.21, 95% CI 0.99-1.48); the CIs included the null values. The HRs, however, were more pronounced for the highest level of duration, frequency, regularity, and timing for all-cause, but not breast cancer-specific mortality. Interactions with BMI revealed no significant heterogeneity (p_interaction = 0.37 and p_interaction = 0.36, respectively).

CONCLUSION

Pre-diagnosis aspirin use was not strongly associated with mortality following breast cancer. The all-cause mortality associations, however, were slightly stronger when we considered patterns of use.

Obesity and Breast Cancer: A Complex Relationship

As prevalence of obesity continues to rise in the United States, we are beginning to elucidate the complex role of obesity-associated chronic inflammation, endocrine dysfunction, and hormone production as a driver for increased breast cancer risk. Epidemiological data suggest that obesity (BMI > 30) is associated with increased breast cancer incidence, worse prognosis, and higher mortality rates. Mechanistically, obesity and excess fat mass represent a state of chronic inflammation, insulin resistance, adipokine imbalance, and increased estrogen signaling. This pro-tumorigenic environment stimulates cancer development through abnormal growth, proliferation, and survival of mammary tissue. Importantly, obesity is a modifiable risk factor; alterations in cell proliferation, apoptosis, circulating estrogen, and insulin sensitivity are observed in response to weight loss attainable through behavior modification including dietary and exercise changes.

Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway

Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

Racial and Ethnic Differences in Breast Cancer Survival: Mediating Effect of Tumor Characteristics and Sociodemographic and Treatment Factors

PURPOSE

To evaluate the relationship between race/ethnicity and breast cancer-specific survival according to subtype and explore mediating factors.

PATIENTS AND METHODS

Participants were women presenting with stage I to III breast cancer between January 2000 and December 2007 at National Comprehensive Cancer Network centers with survival follow-up through December 2009. Cox proportional hazards regression was used to compare breast cancer-specific survival among Asians (n = 533), Hispanics (n = 1,122), and blacks (n = 1,345) with that among whites (n = 14,268), overall and stratified by subtype (luminal A like, luminal B like, human epidermal growth factor receptor 2 type, and triple negative). Model estimates were used to derive mediation proportion and 95% CI for selected risk factors.

RESULTS

In multivariable adjusted models, overall, blacks had 21% higher risk of breast cancer-specific death (hazard ratio [HR], 1.21; 95% CI, 1.00 to 1.45). For estrogen receptor-positive tumors, black and white survival differences were greatest within 2 years of diagnosis (years 0 to 2: HR, 2.65; 95% CI, 1.34 to 5.24; year 2 to end of follow-up: HR, 1.50; 95% CI, 1.12 to 2.00). Blacks were 76% and 56% more likely to die as a result of luminal A-like and luminal B-like tumors, respectively. No disparities were observed for triple-negative or human epidermal growth factor receptor 2-type tumors. Asians and Hispanics were less likely to die as a result of breast cancer compared with whites (Asians: HR, 0.56; 95% CI, 0.37 to 0.85; Hispanics: HR, 0.74; 95% CI, 0.58 to 0.95). For blacks, tumor characteristics and stage at diagnosis were significant disparity mediators. Body mass index was an important mediator for blacks and Asians.

CONCLUSION

Racial disparities in breast cancer survival vary by tumor subtype. Interventions are needed to reduce disparities, particularly in the first 2 years after diagnosis among black women with estrogen receptor-positive tumors.

Targeting the COX-2 Pathway to Improve Therapeutic Response in the Obese Breast Cancer Patient Population

Multiple studies have demonstrated that obesity is associated with a worse outcome for all breast cancer subtypes and that obese breast cancer patients do not respond as well as normal weight patients to aromatase inhibitor treatment and chemotherapy. While a number of mechanisms have been proposed to explain this link, recent studies have provided evidence that elevated local cyclooxygenase-2 (COX-2) expression and the resulting increase in prostaglandin E2 (PGE2) production may play an important role. COX-2 upregulation in breast tumors is associated with a poor prognosis, a connection generally attributed to PGE2's direct effects on apoptosis and invasion as well as its stimulation of pre-adipocyte aromatase expression and subsequent estrogen production. Research in this area has provided a strong foundation for the hypothesis that COX-2 signaling is involved in the obesity-breast cancer link, and further study regarding the role of COX-2 in this link is warranted.

Impact of weight change during neoadjuvant chemotherapy on pathologic response in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an uncommon but aggressive subtype of breast cancer. Obesity has been associated with an increased risk of breast cancer and worse prognosis. Some studies suggest that obese patients are less likely to achieve pathologic complete response (pCR) to neoadjuvant chemotherapy (NCT) and experience worse overall survival. Ki-67 is a proliferation marker that correlates with tumor aggressiveness. The goal of this study was to examine the impact of weight change during NCT for TNBC on pathologic response and Ki-67 reduction. Retrospective review identified 173 TNBC patients treated between 2004 and 2011. Data were collected on patient demographics, pre- and post-NCT body mass index (BMI), Ki-67, and pCR. Data analysis was performed using the two-tailed Student's t-test, analysis of variance (ANOVA), and Fisher's exact test. Sixty-six patients met final study criteria. Forty-three patients lost weight during chemotherapy and 23 gained weight. Patients in the weight gain group were significantly younger (P = 0.0013). There was no significant difference between the two groups in terms of Ki-67 reduction (P = 0.98) or pCR (P = 0.58). When patients were separated into normal weight (BMI<25 kg/m(2) ), overweight (BMI ≥ 25 and <30 kg/m(2) ), and obese (BMI ≥ 30 kg/m(2) ), there was no significant difference in Ki-67 among those groups either before or after NCT. The degree of obesity did not have a significant impact on Ki-67 reduction. Weight change during NCT does not appear to correlate with Ki-67 change or achieving pCR in TNBC. This may reflect the nature of this subtype of breast cancer that is less responsive to the hormonal effects that adipose tissue exerts on cancer cell proliferation.

Association of Body Mass Index Changes during Neoadjuvant Chemotherapy with Pathologic Complete Response and Clinical Outcomes in Patients with Locally Advanced Breast Cancer

The purpose of this study was to determine the association between body mass index (BMI) measurements (baseline BMI and changes in BMI during neoadjuvant systemic treatment [NST]) and clinical efficacy (pathologic complete response [pCR] rate and survival outcomes) in locally advanced breast cancer (LABC). We hypothesized that high baseline BMI and increases in BMI during NST are associated with lower pCR rates and poorer clinical outcomes in LABC.

We retrospectively reviewed the medical records of 1002 patients, 204 with primary inflammatory breast cancer (IBC) and 798 with stage III non-IBC, who underwent standard NST and definitive surgery between November 1, 2006, and December 31, 2012.

The median follow-up time for the survivors was 19.6 months (0.4 - 67.8 months). The pCR rates of patients whose BMI increased or decreased were 23.2% and 18.1%, respectively, (p=0.048). The unadjusted overall survival (OS) was significantly better in the group with increased BMI (p=0.006). However, increased BMI was not an independent predictor of pCR and clinical outcomes (recurrence-free survival and OS) after adjusting for other clinical variables. In subset analyses, increased BMI as a continuous variable was an independent predictor of higher pCR rates in the normal BMI/underweight group (odds ratio [OR]=1.35, 95% confidence interval [CI]: 1.06-0.71, p=0.015). Increased BMI (BMI change ≥0 vs. <0) was also an independent predictor of pCR (OR=1.65, 95% CI: 1.00-2.72, p=0.049) in the postmenopausal group.

Our results show that increasing BMI shows improved clinical outcome in terms of better pCR rates in normal BMI/underweight group and in the postmenopausal group. These results contradict previously reported findings on the association between high BMI and poor clinical efficacy regarding pCR rate and survival outcomes in early-stage breast cancer. Thus, the role of BMI in breast cancer may depend on patients' clinical characteristics such as advanced stage.

NSAID use reduces breast cancer recurrence in overweight and obese women: role of prostaglandin-aromatase interactions

Obesity is associated with a worse breast cancer prognosis and elevated levels of inflammation, including greater cyclooxygenase-2 (COX-2) expression and activity in adipose-infiltrating macrophages. The product of this enzyme, the proinflammatory eicosanoid prostaglandin E2 (PGE2), stimulates adipose tissue aromatase expression and subsequent estrogen production, which could promote breast cancer progression. This study demonstrates that daily use of a nonsteroidal anti-inflammatory drug (NSAID), which inhibits COX-2 activity, is associated with reduced estrogen receptor α (ERα)-positive breast cancer recurrence in obese and overweight women. Retrospective review of data from ERα-positive patients with an average body mass index of >30 revealed that NSAID users had a 52% lower recurrence rate and a 28-month delay in time to recurrence. To examine the mechanisms that may be mediating this effect, we conducted in vitro studies that utilized sera from obese and normal-weight patients with breast cancer. Exposure to sera from obese patients stimulated greater macrophage COX-2 expression and PGE2 production. This was correlated with enhanced preadipocyte aromatase expression following incubation in conditioned media (CM) collected from the obese-patient, sera-exposed macrophages, an effect neutralized by COX-2 inhibition with celecoxib. In addition, CM from macrophage/preadipocyte cocultures exposed to sera from obese patients stimulated greater breast cancer cell ERα activity, proliferation, and migration compared with sera from normal-weight patients, and these differences were eliminated or reduced by the addition of an aromatase inhibitor during CM generation. Prospective studies designed to examine the clinical benefit of NSAID use in obese patients with breast cancer are warranted.

Obesity enhances nongenomic estrogen receptor crosstalk with the PI3K/Akt and MAPK pathways to promote in vitro measures of breast cancer progression

Introduction

Epidemiological and clinical studies indicate that obesity is associated with a worse postmenopausal breast cancer prognosis and an increased risk of endocrine therapy resistance. However, the mechanisms mediating these effects remain poorly understood. Here we investigate the molecular pathways by which obesity-associated circulating factors in the blood enhance estrogen receptor alpha (ERα) positive breast cancer cell viability and growth.

Methods

Blood serum was collected from postmenopausal breast cancer patients and pooled by body mass index (BMI) category (Control: 18.5 to 24.9 kg/m²; Obese: ≥30.0 kg/m²). The effects of patient sera on MCF-7 and T47D breast cancer cell viability and growth were examined by MTT and colony formation assays, respectively. Insulin-like growth factor receptor 1(IGF-1R), Akt, and ERK1/2 activation and genomic ERα activity were assessed to determine their possible contribution to obese patient sera-induced cell viability and growth. To further define the relative contribution of these signaling pathways, cells grown in patient sera were treated with various combinations of ERα, PI3K/Akt and MAPK targeted therapies. Comparisons between cells exposed to different experimental conditions were made using one-way analysis of variance (ANOVA) and Student's t test.

Results

Cells grown in media supplemented with obese patient sera displayed greater cell viability and growth as well as IGF-1R, Akt and ERK1/2 activation relative to control sera. Despite the lack of a significant difference in genomic ERα activity following growth in obese versus control patient sera, we observed a dramatic reduction in cell viability and growth after concurrent inhibition of the ERα and PI3K/Akt signaling pathways. Further, we demonstrated that ERα inhibition was sufficient to attenuate obese serum-induced Akt and ERK1/2 activation. Together, these data suggest that obesity promotes greater ERα positive breast cancer cell viability and growth through enhanced crosstalk between nongenomic ERα signaling and the PI3K/Akt and MAPK pathways.

Conclusions

Circulating factors in the serum of obese postmenopausal women stimulate ERα positive breast cancer cell viability and growth by facilitating non-genomic ERα crosstalk with the PI3K/Akt and MAPK signaling pathways. These findings provide valuable insight into one mechanism by which obesity may promote ERα positive postmenopausal breast cancer progression and endocrine therapy resistance.

Obesity-associated systemic interleukin-6 promotes pre-adipocyte aromatase expression via increased breast cancer cell prostaglandin E2 production

Obesity is associated with a worse breast cancer prognosis, particularly in estrogen receptor alpha (ERα) positive, postmenopausal patients. We hypothesized that this is mediated in part by an elevation in breast cancer cell cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production that results in greater local pre-adipocyte aromatase expression. We utilized an in vitro model of the obese patient's tumor microenvironment in which cultured MCF-7 breast cancer cells and pre-adipocytes were exposed to pooled serum from obese (OB; BMI ≥ 30.0 kg/m(2)) or normal weight (N; BMI 18.5-24.9 kg/m(2)) postmenopausal women. Exposure to OB versus N sera significantly increased MCF-7 cell COX-2 expression and PGE2 production. Pre-adipocyte aromatase expression was 89 % greater following culture in conditioned media (CM) from MCF-7 cells exposed to OB versus N sera (OB-CM and N-CM, respectively), a difference nullified by MCF-7 cell treatment with the COX-2 inhibitor celecoxib. Previous analysis of the sera revealed significantly higher interleukin-6 (IL-6) concentrations in the OB versus N samples. Depletion of IL-6 from the sera neutralized the difference in pre-adipocyte aromatase expression stimulated by OB-CM versus N-CM. Finally, CM from pre-adipocyte/MCF-7 cell co-cultures exposed to OB sera stimulated greater MCF-7 and T47D breast cancer cell ERα activity and proliferation in comparison to N sera. This study indicates that obesity-associated systemic IL-6 indirectly enhances pre-adipocyte aromatase expression via increased breast cancer cell PGE2 production. Investigation regarding the efficacy of a COX-2 inhibitor/aromatase inhibitor combination therapy in the obese postmenopausal patient population is warranted.

Body mass index, tumor characteristics, and prognosis following diagnosis of early-stage breast cancer in a mammographically screened population

PURPOSE

Many studies suggest increased body mass index (BMI) is associated with worse breast cancer outcomes, but few account for variability in screening, access to treatment, and tumor differences. We examined the association between BMI and risk of breast cancer recurrence, breast cancer-specific mortality, and all-cause mortality, and evaluated whether tumor characteristics differ by BMI among a mammographically screened population with access to treatment.

METHODS

Using a retrospective cohort study design, we followed 485 women aged ≥40 years diagnosed with stage I/II breast cancer within 24 months of a screening mammogram occurring between 1988 and 1993 for 10-year outcomes. BMI before diagnosis was categorized as normal (<25 kg/m(2)), overweight (25-29.9 kg/m(2)), and obese (≥30 kg/m(2)). Tumor marker expression was assessed via immunohistochemistry using tissue collected before adjuvant treatment. Medical records were abstracted to identify treatment, recurrence, and mortality. We used Cox proportional hazards to separately model the hazard ratios (HR) of our three outcomes by BMI while adjusting for age, stage, and tamoxifen use.

RESULTS

Relative to normal-weight women, obese women experienced increased risk of recurrence (HR 2.43; 95 % CI 1.34-4.41) and breast cancer death (HR 2.41; 95 % CI 1.00-5.81) within 10 years of diagnosis. There was no association between BMI and all-cause mortality. Obese women had significantly faster growing tumors, as measured by Ki-67.

CONCLUSIONS

Our findings add to the growing evidence that obesity may contribute to poorer breast cancer outcomes, and also suggest that increased tumor proliferation among obese women is a pathway that explains part of their excess risk of adverse outcomes.

Obesity in cancer survival

Although obesity is a well-known risk factor for several cancers, its role on cancer survival is poorly understood. We conducted a systematic literature review to assess the current evidence evaluating the impact of body adiposity on the prognosis of the three most common obesity-related cancers: prostate, colorectal, and breast. We included 33 studies of breast cancer, six studies of prostate cancer, and eight studies of colo-rectal cancer. We note that the evidence overrepresents breast cancer survivorship research and is sparse for prostate and colorectal cancers. Overall, most studies support a relationship between body adiposity and site-specific mortality or cancer progression. However, most of the research was not specifically designed to study these outcomes and, therefore, several methodological issues should be considered before integrating their results to draw conclusions. Further research is urgently warranted to assess the long-term impact of obesity among the growing population of cancer survivors.

Health behaviors among cancer survivors receiving screening mammography

OBJECTIVES

The purpose of this study was to evaluate the prevalence of cancer-related behavioral risk factors among female cancer survivors, relative to women without a previous diagnosis of cancer.

METHODS

In a large cohort of 19,948 women presenting for screening mammography, questionnaires on health behaviors were administered.

RESULTS

A total of 18,510 had detailed history on health behaviors and previous cancer history. Overall 2713 (14.7%) reported a previous cancer history. We found statistically significant results indicating that cancer survivors were less likely than those with no cancer history to: report their overall health as "excellent" (13.6% vs. 21.5%), to engage in moderate or strenuous exercise (56.5% vs. 63.3%), and to use complementary and alternative medicine (57.4% vs. 60.2%). Conversely, cancer survivors were more likely to be current smokers (6.3% vs. 5.5%), rate their overall health as "poor" (15.8% vs. 9.1%), and to report more weight gain over time. Among cancer survivors, differences also emerged by the type of primary cancer. For example, cervical cancer survivors (n = 370) were most likely to report being current smokers (15.7%) and regular alcohol users (71.7%) compared with other survivors. Ovarian (n = 185) and uterine (n = 262) cancer survivors most frequently reported being obese (41% and 34.4%, respectively). Cervical cancer survivors reported the largest weight gain (4.9 lbs at 5 y and 13.4 lbs at 10 y).

CONCLUSIONS

These results suggest opportunities for tailored behavioral health risk factor interventions for specific populations of cancer survivors.

Chemotherapy dosing strategies in the obese, elderly, and thin patient: results of a nationwide survey

PURPOSE

Determining the optimal starting dose of chemotherapy (CHT) presents a considerable challenge when using body-surface area (BSA)-based dosing, particularly in obese, elderly, or thin patients. We sought to document the range of approaches employed when administering CHT to these patients.

METHODS

A questionnaire was developed by a panel of oncologists and mailed to all members of the Medical Oncology Group of Australia.

RESULTS

From 315 oncologists, 188 responded (response rate 59.7%). BSA-based dosing is standard practice for 176 (97.2%) of the responding oncologists. In the adjuvant disease setting, 23 (12.7%) use ideal rather than actual body weight (BW) to calculate BSA, or choose whichever is less. When treating obese patients, only 6.1% of respondents routinely use actual BW. Of the remainder, 69.5% either cap the dose at 2 m(2) or use ideal BW. In underweight patients, 95% (n = 171) routinely calculate BSA using actual BW. Forty one respondents (22.7%) routinely reduce dose in the fit elderly.

CONCLUSION

This analysis of BSA-based CHT dosing methods demonstrates significant variability in practice. Based on evidence from adjuvant studies showing that actual BSA-based dosing is desirable, a substantial number of Australian patients are being underdosed. Further education, together with ongoing research, is required to optimize individualized dosing for efficacy and tolerability.

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.

Weight gain after adjuvant chemotherapy in patients with early breast cancer in Istanbul Turkey

Weight gain is a well-known and unwanted complication of adjuvant chemotherapy in breast cancer. We observed that the female Turkish cancer patients frequently gain weight with adjuvant treatment of breast cancer and planned to examine the magnitude of this problem in early breast cancer patients treated at our hospital. A total of 176 early breast cancer patients who received their adjuvant systemic therapy in Marmara University Hospital between 2003 and 2007 are included in the study. We recorded their weight before and after chemotherapy and also a year after chemotherapy to find out whether the change with weight is transitory. We have also recorded demographic information, including the educational level, menopausal status, the type of chemotherapy or hormonal treatment administered stage of disease, marital status, occupation and the underlying diseases to analyze the relationship between change in weight and these parameters. Median age of patients was 53 and 72% of patients were postmenopausal. Educational level was equally distributed for primary education (27%), high school (40%), and university (33%). The majority of the patients (76%) was married, had two children (69%) and was housewife (60%). Family history of any cancer was high (32%). Most of the patients had stage II cancer (56%), received anthracyclines+/- taxane based chemotherapy (98%) and had no underlying disease (68%). The majority also did not smoke (73%) or drink alcohol (93%). A total of 67% and 72% patients gained weight upon completion and one year after completion of chemotherapy. Mean weight before the chemotherapy, upon completion of chemotherapy and one year after completion of chemotherapy were 68.9 kg, 70.6 kg (P = 0.000) and 71.9 kg (P = 0.000) respectively. Mean body mass index was 27.1 at baseline, 27.8 upon completion of chemotherapy (P = 0.000) and 28.3 one year after completion of chemotherapy (P = 0.000). Age, menopausal status, multiparity and presence of comorbid diseases had statistically significant impact on weight gain following adjuvant therapy in breast cancer patients (P = 0.000, P = 0.008, P = 0.015 and P = 0.017 respectively). This study shows that Turkish women with early breast cancer gain weight after adjuvant systemic therapy, in line with European and American counterparts. This increase in weight is maintained at least one year after adjuvant therapy. Given the adverse consequences of weight gain in terms of both breast cancer prognosis and general health, it is necessary to inform patients about this change and to develop strategies for weight maintenance during and after systemic therapy.

Impact of a raised body mass index on breast cancer survival in relation to age and disease extent at diagnosis

The prognostic value of Body Mass Index (BMI) on breast cancer outcome is controversial and previous studies from this unit have not shown any significant relation to survival. The aim of this study was to re-examine any impact of a raised BMI on recurrence and survival related to age and disease stage at the time of diagnosis. Breast cancer patients (2,298) were reviewed and divided in groups by BMI. Recurrence Free Survival (RFS), Breast Cancer Specific Survival (BCSS), and Overall Survival (OS) were compared by Kaplan-Meier life table analysis. Known prognostic factors including BMI were tested for independent prognostic significance in a Cox's regression model. Obese patients (417) had on average larger tumors (median 2.3 versus 2.1 cm, p < 0.01). A trend to an increased positive node status (37% versus 33%) was not significant, p = 0.18. Seven-year RFS was 82% versus 77% in the obese, p < 0.01, BCSS was 87% versus 85%, p = 0.046 and OS 81% versus 77%, p = 0.02. BMI was independently associated with RFS in multivariate analysis (HR: 1.43, p < 0.01). In subgroup analysis, survival differences were most prominent in patients with node positive disease and in patients <60-years old. Breast cancer outcome was worse in patients with a raised BMI and this risk was greater in younger patients and in those with node positive disease. The difference may be related to diagnosis at a more advanced stage in the obese but there was also an independent effect of BMI on survival.

Serum lipid profile of breast cancer patients

The purpose of this study was to carry out a comparative study to investigate the effect of lipid profile, oestradiol and obesity on the risk of a woman developing breast cancer. This study was carried out at the Komfo Anokye Teaching Hospital (KATH), Peace and Love Hospital, Oduom, Kumasi and Redeemed Clinic, Nima, Accra between May 2002 and March 2003. In this study, 200 consented women comprising 100 breast cancer patients (43 pre- and 57 post-menopausal) and 100 controls (45 pre- and 55 post-menopausal) with similar age range (25 to 80 years) were assessed for lipid profile, oestradiol and BMI. There was a significant increase in Body Mass Index (BMI) (p = 0.011), Total Cholesterol (TC) (p < 0.001), triglyceride (p = 0.026) and low density lipoprotein (LDL-cholesterol) (p = 0.001) of the breast cancer patients compared to the controls. With the exception of oestradiol (EST) that decreased, the lipid profile generally increased with age in both subjects and controls with the subjects having a much higher value than the corresponding control. There was also a significant positive correlation between BMI and TC (r2 = 0.022; p = 0.002) and also between BMI and LDL-cholesterol (r2 = 0.031; p = 0.0003). Apart from EST and LDL-cholesterol that were increased significantly only in the postmenopausal phase in comparison to the controls, BMI, TC and TG were increased in both pre-menopausal and post menopausal phases with HDL-cholesterol remaining unchanged. This study confirms the association between dyslipidaemia, BMI and increased breast cancer risk.

Relationship between obesity and pathologic response to neoadjuvant chemotherapy among women with operable breast cancer

PURPOSE

To understand the mechanism through which obesity in breast cancer patients is associated with poorer outcome, we evaluated body mass index (BMI) and response to neoadjuvant chemotherapy (NC) in women with operable breast cancer.

PATIENTS AND METHODS

From May 1990 to July 2004, 1,169 patients were diagnosed with invasive breast cancer at M. D. Anderson Cancer Center and received NC before surgery. Patients were categorized as obese (BMI >or= 30 kg/m(2)), overweight (BMI of 25 to < 30 kg/m(2)), or normal/underweight (BMI < 25 kg/m(2)). Logistic regression was used to examine associations between BMI and pathologic complete response (pCR). Breast cancer-specific, progression-free, and overall survival times were examined using the Kaplan-Meier method and Cox proportional hazards regression analysis. All statistical tests were two-sided.

RESULTS

Median age was 50 years; 30% of patients were obese, 32% were overweight, and 38% were normal or underweight. In multivariate analysis, there was no significant difference in pCR for obese compared with normal weight patients (odds ratio [OR] = 0.78; 95% CI, 0.49 to 1.26). Overweight and the combination of overweight and obese patients were significantly less likely to have a pCR (OR = 0.59; 95% CI, 0.37 to 0.95; and OR = 0.67; 95% CI, 0.45 to 0.99, respectively). Obese patients were more likely to have hormone-negative tumors (P < .01), stage III tumors (P < .01), and worse overall survival (P = .006) at a median follow-up time of 4.1 years.

CONCLUSION

Higher BMI was associated with worse pCR to NC. In addition, its association with worse overall survival suggests that greater attention should be focused on this risk factor to optimize the care of breast cancer patients.

Overweight, obesity and breast cancer prognosis: optimal body size indicator cut-points

BACKGROUND

Evidence from the data provided in numerous published articles indicates that obesity and overweight can have a negative prognosis role in breast cancer. However, different Body Size Indicators (BSI) and cut-points have been employed and may partly explain discrepancies between the findings of various studies.

MATERIAL AND METHODS

14,709 women were recruited, treated and followed for a first unilateral breast cancer. After randomly splitting the patients' data into two groups, a maximum statistical outcome approach was used to select optimal BSI cut-points from a "training sample", when prognosis events were investigated. External validation was then carried out using a "validation sample", and agreement between the selected optimal BSI cut-points was assessed. Body Mass Index (BMI), weight (W), Ideal Weight Ratio (IWR) and Body Surface Area (BSA) were used, and were assessed at the time of diagnosis.

RESULTS

The selected optimal BSI cut-points were reliable when overall survival, metastasis recurrence and disease free interval events were investigated. The chosen BMI cut-point values matched the overweight cut-point value given by the World Health Organization. Agreement between defined binary BSI was acceptable; however, it varied from "fair" to "very good". Analysis of second primary cancer occurrence and contralateral recurrence events was not conclusive. When local and node recurrence events were taken into account, the results were inconsistent and were linked to an unconfirmed relationship between stoutness and these prognosis events.

CONCLUSIONS

Efficient, optimal BSI cut-points indicate a poorer prognosis, illustrated by a shortened overall survival and an increase of metastasis recurrences, from a BMI value of 25 kg/m(2), a W value of 60 kg, an IWR value of 20% and a BSA value of 1.7 m(2). Further BSI cut-point investigations are needed, taking into account contralateral recurrence and second primary cancer events.

Obesity and HER 2 overexpression: a common factor for poor prognosis of breast cancer

Background

Both obesity and over-expression of HER II are associated with poor prognosis of breast cancer. In vitro experiments suggest that anti-tumour activity of the anti-obesity drug Orlistat is likely to be due to transcriptional suppression of HER II expression. The overexpression of HER II is also positively correlated with other markers of prognosis of breast cancer such as cathepsin expression.

Hypothesis

The hypothesis we tested was that the obese women with breast cancer might over-express HER II more often than their lean counterparts to account for the poor prognosis.

Patients and methods

One hundred consecutive patients were included in this study. Their body mass indexes were correlated with overexpression of HER II.

Results

There was also no association between oestrogen or progesterone receptor positivity and obesity or HER II over expression in premenopausal or post-menopausal women with breast cancer.

Conclusion

The present study demonstrated that the poor outcome of breast cancer in obese patients is not due to over expression of HER II.

Association of Body Mass Index With Response and Survival in Men With Metastatic Prostate Cancer: Southwest Oncology Group Trials 8894 and 9916

PURPOSE

We evaluated the effect of body mass index on prostate specific antigen response, and progression-free and overall survival in men with androgen dependent or androgen independent metastatic prostate cancer.

MATERIALS AND METHODS

We examined the prognostic impact of body mass index in patient cohorts from phase III randomized studies coordinated by the Southwest Oncology Group. The first study included 1,006 men treated with androgen deprivation for metastatic prostate cancer. The second study included 671 patients treated with chemotherapy for metastatic, androgen independent prostate cancer.

RESULTS

Among men with androgen dependent disease, higher body mass index was associated with longer overall (p <0.001) and progression-free (p = 0.009) survival, as well as with an increased likelihood of achieving a prostate specific antigen nadir less than 4 ng/ml (p = 0.008). In multivariate analysis adjusting for risk factors, increasing body mass index was positively correlated with overall survival (p <0.01) and overweight but not obese patients (body mass index 27 to 29.9) had a significantly improved outcome compared to normal weight patients, with hazard ratios for risk of progression and death of 0.82 (95% CI 0.69, 0.98) and 0.75 (95% CI 0.63, 0.89), respectively. Among men with androgen independent prostate cancer, no clear association could be detected between body mass index and progression-free survival, overall survival or prostate specific antigen response.

CONCLUSIONS

This study revealed higher body mass index to be associated with better overall and progression-free survival in patients with androgen dependent metastatic prostate cancer. Among men who had androgen independent disease, no significant association was found between body mass index and survival.

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.

Within-stage racial differences in tumor size and number of positive lymph nodes in women with breast cancer

BACKGROUND

Black women have higher breast cancer mortality rates, are more likely to be diagnosed at an advanced stage of disease, and have worse stage-for-stage survival than white women. It was hypothesized that differences in the tumor size and number of positive lymph nodes within each disease stage contribute to the survival disparity.

METHODS

In the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, black and white women diagnosed with a first primary tumor (TNM stage I-IIIA breast cancer) between 1988 and 2003 were identified. The demographic and clinical characteristics were compared by race. Logistic regression models of the association between race and tumor size and lymph node status were developed. Cox proportional hazards models of the association between mortality and race, tumor size, lymph node status, and other covariates were also examined.

RESULTS

Among 256,174 SEER cases (21,861 black and 234,313 white women), more black than white women with lymph node-negative breast cancer had tumors measuring >or=2.0 cm. Adjusted for tumor size, more black than white women had >or=1 positive lymph nodes (odds ratio [OR], 1.24; 95% confidence interval [95% CI], 1.20-1.28). The age-adjusted and TNM stage-adjusted mortality rate ratio for blacks versus whites was 1.56 (95% CI, 1.51-1.61). Adjustment for within-stage differences in tumor size and lymph node involvement were found to have a negligible effect. With adjustment for additional covariates, the rate ratio was 1.39 (95% CI, 1.35-1.44). In addition, the rate ratio reflecting racial disparity increased as the stage of disease increased. CONCLUSIONS.: Adjusting for within-stage differences in tumor size and lymph node status did not appear to reduce the racial disparity. The finding that disparities increased with higher stage of disease suggests that interventions aimed at reducing these differences should target women with more advanced disease.

Receipt of appropriate primary breast cancer therapy and adjuvant therapy are not associated with obesity in older women with access to health care

PURPOSE

Many studies have reported body mass index (BMI) increases the risk of breast cancer recurrence and breast cancer-specific mortality. Few studies have reported or examined whether breast cancer treatment differs by BMI. The purpose of this study was to examine the association between BMI at breast cancer diagnosis and receipt of appropriate primary tumor therapy and adjuvant therapy.

METHODS

We identified 897 women age >or= 65 years diagnosed with stage I or II breast cancer from 1990 to 1999 at five health care organizations. We used medical records to confirm demographics, tumor characteristics, treatment, comorbid conditions, and to calculate BMI at diagnosis (< 25 kg/m(2), n = 328; 25 to < 30 kg/m(2), n = 305; 30 to < 35 kg/m(2), n = 188; >or= 35 kg/m(2), n = 76). We defined primary therapy based on National Guidelines as receiving breast-conserving surgery with radiation therapy and axillary node dissection, simple mastectomy with axillary node dissection, or modified radical mastectomy (73% overall); adjuvant therapy was defined as receipt of hormonal therapy, chemotherapy, or both (60% overall).

RESULTS

The median BMI was 26.7 kg/m(2) (range, 14.6 to 61.2). The proportion of women receiving primary therapy and adjuvant therapy was lowest for women less than 25 kg/m(2) (69% and 56%, respectively) and greatest for obese I (78% and 64%, respectively). There were no differences in receipt of primary or adjuvant treatment across BMI in univariate or multivariable models (after adjusting for age, stage, comorbidity, diagnosis year, and hormone receptor positivity).

CONCLUSION

Receipt of appropriate primary therapy and adjuvant therapy is not associated with BMI in older women with access to health care. Additional research in larger samples and more diverse settings is needed.

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.

Prospective, longitudinal study of leisure-time exercise in women with early-stage breast cancer

Physical activity can have a beneficial effect on both physical and mental health in cancer survivors. However, evidence from cross-sectional and/or retrospective research suggests that cancer treatment can be associated with both short- and long-term reductions in physical activity. A prospective, longitudinal research design was used to examine the trajectory of leisure-time exercise in early-stage breast cancer patients from two treatment centers (n = 231). Participation in mild, moderate, and strenuous leisure-time exercise was assessed before, during, and following completion of adjuvant radiotherapy (n = 136) or chemotherapy + radiation (n = 95). Results indicated significant decreases, relative to pre-diagnosis baseline, in total estimated weekly metabolic equivalents and minutes of leisure-time exercise during adjuvant therapy for both the radiotherapy and chemotherapy + radiation groups. However, activity levels seemed to quickly recover and did not differ from pre-diagnosis baseline at assessments 2 and 6 months following completion of adjuvant radiotherapy or chemotherapy + radiation. Although suggesting little effect of breast cancer diagnosis and treatment on participation in leisure-time exercise at 6-month follow-up, these group analyses obscure the fact that a large number of individuals (35.5%) exhibited clinically significant change, both decreases or increases, in total weekly metabolic equivalents between pre-diagnosis baseline and 6-month follow-up. Fostering appropriate participation in physical activity in cancer patients and survivors is likely to be enhanced by better understanding of the beliefs and motivations that underlie spontaneous changes in participation in leisure-time exercise.

Relation of Body Mass Index (BMI) to Disease Free (DFS) and Distant Disease Free Survivals (DDFS) Among Turkish Women with Operable Breast Carcinoma

BACKGROUND

The correlation between body mass index (BMI) and patient and tumor characteristics related to prognosis has not been well explored and may help to elucidate the mechanisms involved in the carcinogenesis. Because of the equivocal, inconsistent and uncertain research results as well as racial and ethnic differences, we aimed to evaluate the prognostic significance of high BMI in Turkish women with operable breast carcinoma.

METHODS

Two hundred and sixty-six patients who had operable invasive breast carcinoma diagnosed from 2000 through 2004 in a single institution were evaluated for their demographic features, BMI, histopathological/immunohistochemical examinations and treatments. Quetelet BMI [weight (kg)/height (m)2] categories were selected according to the World Health Organization definition. Disease free survival (DSF) as well as distant disease free survival (DDSF) analyses were performed to identify independent prognostic factors.

RESULTS

Post-menopausal patients were significantly in the higher quartile of BMI than pre-menopausal patients (P = 0.003). While post-menopausal obese patients had worse DSF and DDFS (P = 0.001), vascular invasion was the independent prognostic factor for both survival indices (P = 0.031).

CONCLUSIONS

Post-menopausal obese Turkish women are at increased risk of developing breast tumors with aggressive phenotype and obesity is a strong predictor of poor DSF and DDFS. Preventive strategies to reduce not only the prevalence of obesity and breast cancer but also the mortality must be recognized as the cost-effective public-health policy for Turkey.

Effect of patient socioeconomic status and body mass index on the quality of breast cancer adjuvant chemotherapy

PURPOSE

The purpose of this study was to investigate the relationship between socioeconomic status (SES) and the use of intentionally reduced doses of chemotherapy in the adjuvant treatment of breast cancer.

PATIENTS AND METHODS

Patients with breast cancer treated with a standard chemotherapy regimen (n = 764) were enrolled in a prospective registry after signing informed consent. Detailed information was collected on patient, disease, and treatment, including chemotherapy doses. Zip code level data on median household income, proportion of people living below the poverty level, and educational attainment were obtained from the US Census. Doses for the first cycle of chemotherapy lower than 85% of standard were considered to be reduced. Univariate analyses and multivariate logistic regression were performed to identify factors associated with the use of reduced first cycle doses.

RESULTS

In univariate analysis, individual education attainment, zip code SES measures, body mass index, and geographic region were all significantly associated with receipt of intentionally reduced doses of chemotherapy. In multivariate analysis, controlling for geography, factors independently associated with reduced doses were obesity (odds ratio [OR], 2.47; 95% CI, 1.36 to 4.51), severe obesity (OR, 4.04; 95% CI, 1.46 to 11.19), and education less than high school (OR, 3.07; 95% CI, 1.57 to 5.99).

CONCLUSION

Social disparities in breast cancer outcomes may be in part the result of lower quality chemotherapy doses in the adjuvant treatment of breast cancer. Efforts to address such prescribing patterns may help reduce SES disparities in breast cancer survival.

Obesity and prognosis of breast cancer

Obesity has a complicated relationship to both breast cancer risk and the clinical behaviour of the established disease. It is suggested that obesity is associated with both an increased risk of developing breast cancer risk and worse prognosis after disease onset. In post-menopausal women, various measures of obesity such as body mass index, weight, weight gain and waist : hip ratio have all been positively associated with risk of developing breast cancer. In most but not all case-control and prospective cohort studies, an inverse relationship has been found between weight and breast cancer among pre-menopausal women. Some data suggest that adult weight gain and central obesity increase the risk of pre-menopausal breast cancer. Obesity at the time of diagnosis is thought to be significant as a poor prognostic factor. Obesity is associated with adverse outcomes in both pre- and post-menopausal women with breast cancer. Many cancer survivors seek ways to minimize the risk of recurrence and death because of breast cancer. Despite complex and at times controversial data, enough evidence is available at present to suggest that weight management should be a part of the strategy to prevent the occurrence, recurrence and death because of breast cancer. In this review the effect of obesity on the prognosis of breast cancer is examined in detail.

Risk factors for breast carcinoma in situ versus invasive breast cancer in a prospective study of pre- and post-menopausal women

Risk factors for breast carcinoma in situ and invasive breast cancer were compared using data from 61,844 women (61% post-menopausal) with no prior breast cancer and at least one screening mammogram between April 1, 1996 and June 30, 2001. The women were followed until a subsequent mammogram before July 1, 2001, or a benign biopsy or breast cancer diagnosis before June 30, 2002. A total of 1,191 breast cancers (300 in situ and 891 invasive) were diagnosed during an average follow-up of 3.1 years. Multivariate Cox regression models were used to estimate the relative risks (RR) of in situ and invasive cancer associated with family history of breast cancer, age at first childbirth or nulliparity, post-menopausal hormone use, body mass index (BMI), and mammographic breast density. Separate analyses were done for pre- and post-menopausal women. BMI was unrelated to risk of in situ cancer regardless of menopausal status, but was associated with an increased risk of invasive cancer in post-menopausal women (RR = 1.9 for BMI > or = 30 vs. BMI < 22, 95% confidence interval 1.4-2.5). Later childbearing and nulliparity were more strongly associated with in situ than invasive cancer in pre-menopausal women. Post-menopausal hormone use was more strongly associated with invasive disease. RR associated with family history and breast density were similar for in situ cancer and invasive cancer. Results indicating that BMI is related to post-menopausal invasive cancers but unrelated to in situ cancers are consistent with the hypothesis that concomitants of obesity activate proliferation.

Obesity and survival in a cohort of predominantly Hispanic children with acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL), the most common malignancy in children, constitutes 25% of all pediatric cancer. Childhood cancer patients who are obese at diagnosis represent a particular challenge for the oncologist. Obesity may complicate chemotherapy dose determination, and has been associated with decreased overall and event-free survival in a number of adult cancer patients, and more recently in pediatric patients. The purpose of the present study was to examine whether obesity at diagnosis was associated with decreased overall and event-free survival in a cohort of 322 predominantly Hispanic pediatric patients with B-precursor ALL. Obesity was classified as an age-standardized and sex-standardized body mass index z-score at or above the 95th percentile. Hazard ratios (HRs) for overall and event-free survival were assessed using Cox proportional hazards regression modeling. Obesity at diagnosis was not associated with decreased overall survival (HR = 1.40, 95% confidence interval = 0.69-2.87) or event-free survival (HR = 1.08, 95% confidence interval = 0.65-1.82) in the overall cohort or in either of the 2 age-at-diagnosis (2 to 9 y; 10 to 18 y) subgroups. Our finding of no obesity-related prognostic effect in the overall cohort and in the under 2 to 9-year age-at-diagnosis cohort was consistent with the previous large-scale study of ALL patients; the absence of a prognostic effect in the 10 to 18-year age-at-diagnosis cohort, however, conflicted with previous findings.

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.

Association of overweight with breast cancer survival

The authors investigated the association between overweight at the time of or soon after cancer diagnosis and survival in a cohort of 1,455 breast cancer patients aged 25-64 years. The patients were recruited into the Shanghai Breast Cancer Study (Shanghai, China), a population-based case-control study, between August 1996 and March 1998. The median follow-up time for this cohort was 5.1 years (1996-2002) after breast cancer diagnosis, and 240 deaths were identified. Being overweight at cancer diagnosis or soon afterward, as measured by body mass index (BMI; weight (kg)/height (m)(2)), was associated with poorer overall survival and disease-free survival. Five-year survival rates were 86.5%, 83.8%, and 80.1% for subjects whose BMIs were <23.0, 23.0-24.9, and >or=25.0, respectively (p = 0.02); the corresponding 5-year disease-free survival rates were 81.9%, 78.1%, and 76.6% (p = 0.05). The inverse association between BMI and survival persisted after adjustment for age at diagnosis and other known prognostic factors for breast cancer, including disease stage. The authors found neither waist:hip ratio nor waist circumference to be independently associated with overall survival or disease-free survival. These results suggest that excess weight may be an independent predictor of breast cancer survival among Chinese women.

Obesity and cardiovascular risk factors in younger breast cancer survivors: The Cancer and Menopause Study (CAMS)

BACKGROUND

Breast cancer patients today can expect long-term survival; however, weight gain is a common problem after treatment and increases the risk for recurrence, cardiovascular disease and diabetes. The multi-ethnic cohort from the Cancer and Menopause Study, designed to examine the reproductive and late cardiovascular health effects of treatment in younger female breast cancer survivors (BCS), was used to describe the relationship of behavioral and treatment variables to body mass index (BMI), physical activity (PA), and cardiovascular risk factors.

METHODS

Stage 0, I or II breast cancer survivors who were < or = 50 years at diagnosis and 2-10 years disease-free survivors (mean 5.9 +/- 2.3 years) were recruited from two tumor registries to complete a mail survey that included information on demographics, health-related quality of life, reproductive health, cancer treatment, PA, weight and height. A sub-sample completed an office visit where fasting blood lipids, blood pressure (BP), height and weight were measured. Linear regression analysis was used to model the following outcomes: BMI, PA, blood lipids and BP.

RESULTS

Current BMI was positively associated with higher BMI prior to diagnosis, unhappiness with body image and negatively associated with current total PA (model p < 0.001). More work, home and leisure PA were all positively associated with greater physical functioning and higher energy levels (all models, p < 0.001). Total and LDL cholesterol were positively associated with number of years since diagnosis and negatively associated with leisure PA (both models, p < 0.001), while systolic and diastolic BP were both positively associated with age, current use of BP medications and current BMI (models, p < 0.001).

CONCLUSIONS

Obesity in these BCS is prevalent and associated with premorbid obesity and decreased current physical activity but not with adjuvant treatment. Given the negative health consequences of weight gain and obesity after breast cancer, continued study of the etiology of weight gain, and potential targets for weight gain prevention are required. Interventions that target PA may be important for weight maintenance in BCS.

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.

A case-control study evaluating the association of purposeful physical activity, body fat distribution, and steroid hormones on premenopausal breast cancer risk

The objective of this case-control study was to investigate the relationship between purposeful physical activity, body fat distribution, body mass index, and steroid hormones. These factors are known to be implicated in modulating breast cancer risk in premenopausal women. A total of 112 newly diagnosed, premenopausal breast cancer patients and 106 age-matched premenopausal disease-free controls were admitted to the study. Information regarding personal, medical, hormonal, and reproductive history, smoking and alcohol use, physical activity history, and anthropometric measurements was obtained. Serum samples for steroid hormone assays were collected and analyzed. Disease-free premenopausal controls had a significantly higher physical activity index (PAI) (p</=0.05), however, significantly higher weight (p</=0.05), body mass index (BMI) (p=0.01), waist (p</=0.005) and hip (p</=0.05) circumferences, waist:hip ratios (p</=0.05), and serum total estradiol levels (p<0.0005) were observed in cancer cases. The final model using stepwise logistic regression analysis indicates that the variables that significantly predicted breast cancer risk were waist:hip ratio (odds ratio [OR]=1.11, p</=0.005) and serum total estradiol levels (OR=1.03, p</=0.0001). Our study provides some evidence that purposeful physical activity may reduce upper body fat distribution associated with adult weight gain. This may be a result of alterations in the steroid hormone pathway, such as reduced estradiol levels. This demonstrates the potential mechanism through which increased physical activity can reduce the risk for breast cancer in premenopausal women.