The effect of body mass index on overall and disease-free survival in node-positive breast cancer patients treated with docetaxel and doxorubicin-containing adjuvant chemotherapy: the experience of the BIG 02-98 trial

Obesity at diagnosis is associated with inferior outcomes in hormone receptor-positive operable breast cancer

BACKGROUND

Obesity has been associated with inferior outcomes in operable breast cancer, but the relation between body mass index (BMI) and outcomes by breast cancer subtype has not been previously evaluated.

METHODS

The authors evaluated the relation between BMI and outcomes in 3 adjuvant trials coordinated by the Eastern Cooperative Oncology Group that included chemotherapy regimens with doxorubicin and cyclophosphamide, including E1199, E5188, and E3189. Results are expressed as hazard ratios (HRs) from Cox proportional hazards models (HR >1 indicates a worse outcome). All P values are 2-sided.

RESULTS

When evaluated as a continuous variable in trial E1199, increasing BMI within the obese (BMI, ≥ 30 kg/m(2)) and overweight (BMI, 25-29.9 kg/m(2)) ranges was associated with inferior outcomes in hormone receptor-positive, human epidermal growth receptor 2 (HER-2)/neu-negative disease for disease-free survival (DFS; P = .0006) and overall survival (OS; P = .0007), but not in HER-2/neu-overexpressing or triple-negative disease. When evaluated as a categorical variable, obesity was associated with inferior DFS (HR, 1.24; 95% confidence interval [CI], 1.06-1.46; P = .0008) and OS (HR, 1.37; 95% CI, 1.13-1.67; P = .002) in hormone receptor-positive disease, but not other subtypes. In a model including obesity, disease subtype, and their interaction, the interaction term was significant for OS (P = .02) and showed a strong trend for DFS (P = .07). Similar results were found in 2 other trials (E5188, E3189).

CONCLUSIONS

In a clinical trial population that excluded patients with significant comorbidities, obesity was associated with inferior outcomes specifically in patients with hormone receptor-positive operable breast cancer treated with standard chemohormonal therapy.

Effect of obesity on toxicity in women treated with adjuvant chemotherapy for early-stage breast cancer: a systematic review

The purpose of this study is to provide more definite evidence regarding the role of dose modification of chemotherapy in obese women with breast cancer by systematically reviewing current literature regarding chemotherapy-induced toxicity rates in obese and non-obese women with early-stage breast cancer. A systematic search of Pubmed and EMBASE was conducted to identify original studies investigating chemotherapy-induced toxicity in obese women receiving adjuvant chemotherapy treatment for breast cancer. Ten studies were identified. We noted low rates of adjustment for confounders such as prophylactic hematopoietic growth factor use and empirical dose reductions. Seven studies found reduced toxicity in obese compared to non-obese women. Of four studies, where dose capping was precluded or statistically adjusted for, three found reduced toxicity in obese women. These outcomes include less febrile neutropenia (body mass index (BMI) >23.6; odds ratio (OR) 4.4; 95 % confidence interval (CI) 1.65-12.01), fewer hospital admissions (BMI >35; OR 0.61, 95 % CI 0.38-0.97), and fewer neutropenic events (BMI >25; OR 0.49; 95 % CI 0.37-0.66). Only a single study reported higher rates of toxicity in obese women, but this study had significant methodological issues. As a conclusion, we observed that obese patients tolerate chemotherapy better than lean patients. However, this may be confounded by poorly specified dose capping practices and the use of hematopoietic growth factors. Further research should focus on improved documentation of body size, of dose, and of use of growth factors, and analysis of how these affect recurrence rates, toxicity, and survival.

Taste alteration in breast cancer patients treated with taxane chemotherapy: experience, effect, and coping strategies

PURPOSE

This study examined the experience and coping strategies for taste alteration in female breast cancer patients treated with docetaxel or paclitaxel.

METHODS

A purposive sample of 25 patients currently receiving docetaxel or paclitaxel or within 6 months of having completed treatment was recruited. Semi-structured interviews and patient-level data were utilized for this exploratory descriptive study. Interview data were analyzed with the constant comparative method; patient-level data were abstracted from the electronic medical record.

RESULTS

Of all side effects reported from taxanes, the most common was taste alteration (8 of 10 docetaxel patients, 3 of 15 paclitaxel patients). Women that experience taste alteration chose not to eat as much, ate on an irregular schedule, and/or lost interest in preparing meals for themselves and/or their family. Women adopted a variety of new behaviors to deal with the taste alteration and its effects, including trying new recipes, eating strongly flavored foods, honoring specific food cravings, eating candy before meals, cutting food with lemon, drinking sweetened drinks, using plastic eating utensils, drinking from a straw, brushing their teeth and tongue before meals, and using baking soda and salt wash or antibacterial mouthwash.

CONCLUSIONS

Taste alteration affects breast cancer patients' lives, and they develop management strategies to deal with the effect. While some self-management strategies can be seen as positively adaptive, the potential for increased caloric consumption and poor eating behaviors associated with some coping strategies may be a cause for concern given the observation of weight gain during breast cancer treatment and association of obesity with poor treatment outcomes in breast cancer patients. Further studies are warranted to determine the overall burden of this symptom and measurement of cancer and non-cancer-related consequences of these behavioral adaptations.

Prognostic and predictive value of TP53 mutations in node-positive breast cancer patients treated with anthracycline- or anthracycline/taxane-based adjuvant therapy: results from the BIG 02-98 phase III trial

INTRODUCTION

Pre-clinical data suggest p53-dependent anthracycline-induced apoptosis and p53-independent taxane activity. However, dedicated clinical research has not defined a predictive role for TP53 gene mutations. The aim of the current study was to retrospectively explore the prognosis and predictive values of TP53 somatic mutations in the BIG 02-98 randomized phase III trial in which women with node-positive breast cancer were treated with adjuvant doxorubicin-based chemotherapy with or without docetaxel.

METHODS

The prognostic and predictive values of TP53 were analyzed in tumor samples by gene sequencing within exons 5 to 8. Patients were classified according to p53 protein status predicted from TP53 gene sequence, as wild-type (no TP53 variation or TP53 variations which are predicted not to modify p53 protein sequence) or mutant (p53 nonsynonymous mutations). Mutations were subcategorized according to missense or truncating mutations. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Cox-regression analysis was used to identify independent predictors of outcome.

RESULTS

TP53 gene status was determined for 18% (520 of 2887) of the women enrolled in BIG 02-98. TP53 gene variations were found in 17% (90 of 520). Nonsynonymous p53 mutations, found in 16.3% (85 of 520), were associated with older age, ductal morphology, higher grade and hormone-receptor negativity. Of the nonsynonymous mutations, 12.3% (64 of 520) were missense and 3.6% were truncating (19 of 520). Only truncating mutations showed significant independent prognostic value, with an increased recurrence risk compared to patients with non-modified p53 protein (hazard ratio = 3.21, 95% confidence interval = 1.740 to 5.935, P = 0.0002). p53 status had no significant predictive value for response to docetaxel.

CONCLUSIONS

p53 truncating mutations were uncommon but associated with poor prognosis. No significant predictive role for p53 status was detected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00174655.

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.

Body mass index and survival after breast cancer diagnosis in Japanese women

BACKGROUND

Body mass index (BMI) may be an important factor affecting breast cancer outcome. Studies conducted mainly in Western countries have reported a relationship between higher BMI and a higher risk of all-cause death or breast cancer-specific death among women with breast cancer, but only a few studies have been reported in Japan so far. In the present prospective study, we investigated the associations between BMI and the risk of all-cause and breast cancer-specific death among breast cancer patients overall and by menopausal status and hormone receptor status.

METHODS

The study included 653 breast cancer patients admitted to a single hospital in Japan, between 1997 and 2005. BMI was assessed using a self-administered questionnaire. The patients were completely followed up until December, 2008. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated according to quartile points of BMI categories, respectively: <21.2, ≥21.2 to <23.3 (reference), ≥23.3 to <25.8 and ≥25.8 kg/m2.

RESULTS

During the follow-up period, 136 all-cause and 108 breast cancer-specific deaths were observed. After adjustment for clinical and confounding factors, higher BMI was associated with an increased risk of all-cause death (HR = 2.61; 95% CI: 1.01-6.78 for BMI ≥25.8 vs. ≥21.2 to <23.3 kg/m²) among premenopausal patients. According to hormonal receptor status, BMI ≥25.8 kg/m² was associated with breast cancer-specific death (HR = 4.95; 95% CI: 1.05-23.35) and BMI <21.2 kg/m2 was associated with all-cause (HR = 2.91; 95% CI: 1.09-7.77) and breast cancer-specific death (HR = 7.23; 95% CI: 1.57-33.34) among patients with ER + or PgR + tumors. Analysis by hormonal receptor status also showed a positive association between BMI and mortality risk among patients with ER + or PgR + tumors and with BMI ≥21.2 kg/m² (p for trend: 0.020 and 0.031 for all-cause and breast cancer-specific death, respectively).

CONCLUSIONS

Our results suggest that both higher BMI and lower BMI are associated with an increased risk of mortality, especially among premenopausal patients or among patients with hormonal receptor positive tumors. Breast cancer patients should be informed of the potential importance of maintaining an appropriate body weight after they have been diagnosed.

Weight management and its role in breast cancer rehabilitation

Overweight and obesity are risk factors for postmenopausal breast cancer, and many women diagnosed with breast cancer, irrespective of menopausal status, gain weight after diagnosis. Weight management plays an important role in rehabilitation and recovery because obesity and/or weight gain may lead to poorer breast cancer prognosis, as well as prevalent comorbid conditions (eg, cardiovascular disease and diabetes), poorer surgical outcomes (eg, increased operating and recovery times, higher infection rates, and poorer healing), lymphedema, fatigue, functional decline, and poorer health and overall quality of life. Health care professionals should encourage weight management at all phases of the cancer care continuum as a means to potentially avoid adverse sequelae and late effects, as well as to improve overall health and possibly survival. Comprehensive approaches that involve dietary and behavior modification, and increased aerobic and strength training exercise have shown promise in either preventing weight gain or promoting weight loss, reducing biomarkers associated with inflammation and comorbidity, and improving lifestyle behaviors, functional status, and quality of life in this high-risk patient population.

Biologic features and prognosis of ductal carcinoma in situ are not adversely impacted by initial large body mass

Obesity is associated with adverse biologic features and poor outcome in patients with invasive breast cancer, yet this relationship has not been evaluated in patients with ductal carcinoma in situ (DCIS). From 1996 to 2009, body mass index (BMI) was recorded at initial diagnosis for 1,885 patients with DCIS treated at our institution. Patients were categorized as obese (BMI ≥ 30 kg/m(2)), overweight (BMI 25 to <30 kg/m(2)), or of normal weight or underweight (BMI < 25 kg/m(2)). Logistic regression was used to examine associations between BMI and patient, clinical, and pathologic features and treatment. Local-regional recurrence was calculated using the Kaplan-Meier method. All statistical tests were two-sided. Of the 1,885 patients, 514 (27.7%) were obese, 510 (27.5%) were overweight, and 831 (44.8%) were normal/underweight. In multivariate analysis, overweight and obese patients were significantly more likely to be African American (odds ratio [OR], 3.93; 95% confidence interval [CI], 2.66-5.80) or Hispanic (OR, 1.44; CI, 1.02-2.04), be postmenopausal (OR, 1.63; CI, 1.28-2.07), have diabetes (OR, 4.60; CI, 2.60-8.12), have estrogen-receptor-positive DCIS (OR, 1.39; CI, 1.00-192), and present with a radiologic abnormality rather than clinical symptoms (OR, 1.35; CI, 1.01-1.80). At a median follow-up time of 4.96 years (range, 1.0-14.34 years), no significant differences in local recurrence rates were detected based on patients' initial BMI category. Furthermore, there was no significant difference in risk of recurrence between diabetic patients receiving metformin or not. In conclusion, higher BMI is not associated with adverse biologic features or prognosis in patients with DCIS.

Insulin- and obesity-related variables in early-stage breast cancer: correlations and time course of prognostic associations

PURPOSE

To investigate patterns of prognostic associations over time of insulin- and obesity-related variables measured at diagnosis of early breast cancer (BC), focusing on whether the prognostic associations with distant recurrence and death changed over time.

PATIENTS AND METHODS

Five hundred thirty-five nondiabetic women with T1-3, N0-1, M0 invasive BC diagnosed from 1989 to 1996 were included in the study. Insulin-related variables included fasting insulin, Homeostasis Model Assessment, C-peptide, and glucose. Obesity-related variables included weight, body mass index (BMI), waist and hip circumference, and leptin. Correlations were examined using the Pearson correlation coefficient and prognostic associations using the Cox model.

RESULTS

There was evidence that associations of baseline insulin-related variables with distant recurrence and death were not constant over time; univariable adverse prognostic associations were significant only during the first 5 years (eg, insulin quartile 4 v 1: hazard ratio [HR], 2.32; 95% CI, 1.39 to 3.86; P < .001 for distant disease-free survival [DDFS]; and HR, 2.85; 95% CI, 1.48 to 5.50; P = .002 for overall survival [OS], with little attenuation of this pattern in multivariable analyses). In contrast, obesity-related variables (BMI, weight, leptin) exerted significant adverse univariable associations that were constant over time (eg, BMI quartile 4 v 2: HR, 1.40; 95% CI, 1.07 to 1.82 for DDFS; P = .014; and HR, 1.50; 95% CI, 1.16 to 1.93; P < .001 for OS); prognostic associations of leptin remained significant in multivariable analyses.

CONCLUSION

Baseline insulin- and obesity-related variables exert different patterns of prognostic associations over time in early BC.

Increased BMI correlates with higher risk of disease relapse and differentiation syndrome in patients with acute promyelocytic leukemia treated with the AIDA protocols

We investigated whether body mass index (BMI) correlates with distinct outcomes in newly diagnosed acute promyelocytic leukemia (APL). The study population included 144 patients with newly diagnosed and genetically confirmed APL consecutively treated at a single institution. All patients received All-trans retinoic acid and idarubicin according to the GIMEMA protocols AIDA-0493 and AIDA-2000. Outcome estimates according to the BMI were carried out together with multivariable analysis for the risk of relapse and differentiation syndrome. Fifty-four (37.5%) were under/normal weight (BMI < 25), whereas 90 (62.5%) patients were overweight/obese (BMI ≥ 25). An increased BMI was associated with older age (P < .0001) and male sex (P = .02). BMI was the most powerful predictor of differentiation syndrome in multivariable analysis (odds ratio = 7.24; 95% CI, 1.50-34; P = .014). After a median follow-up of 6 years, the estimated cumulative incidence of relapse at 5 years was 31.6% (95% CI, 22.7%-43.8%) in overweight/obese and 11.2% (95% CI, 5.3%-23.8%) in underweight/normal weight patients (P = .029). Multivariable analysis showed that BMI was an independent predictor of relapse (hazard ratio = 2.45, 95% CI, 1.00-5.99, in overweight/obese vs under/normal weight patients, P = .049). An increased BMI at diagnosis is associated with a higher risk of developing differentiation syndrome and disease relapse in APL patients treated with AIDA protocols.

A retrospective review of the metabolic syndrome in women diagnosed with breast cancer and correlation with estrogen receptor

Women diagnosed with obesity and breast cancer have an increased risk of recurrence and death (Protani et al., Breast Cancer Res Treat 123:627-635, 1). Obesity is associated with the metabolic syndrome--a pathophysiologically distinct inflammatory process comprised of central obesity, insulin resistance, hypertension, and atherogenic dyslipidemia. The relationship of obesity as a risk factor for breast cancer is complex with a protective effect for younger women in contrast to a risk for older women (Kabat et al., Cancer Epidemiol Biomarkers Prev 18:2046-2053, 2; Ursin et al., Epidemiology 6:137-141, 3). The metabolic syndrome has been associated with the risk of cancer, and pro-inflammatory circulating factors may be associated with risk of more aggressive breast cancer (Capasso et al., Cancer Biol Ther 10:1240-1243, 4; Healy et al., Clin Oncol (R Coll Radiol) 22:281-288, 5; Laukkanen et al., Cancer Epidemiol Biomarkers Prev 13:1646-1650, 6). We conducted a retrospective review of 860 breast cancer patients to determine the relationship between estrogen receptor status and the metabolic syndrome. We collected the relevant metabolic diagnoses, medications, physical findings, and laboratory values and adapted the National Cholesterol Education Program criteria to define the metabolic syndrome retrospectively. No relationship was found between estrogen receptor status and the individual components of the metabolic syndrome. Based on findings in the medical records, 15% of the women with breast cancer had the metabolic syndrome, and 26% of the women were considered obese, 16% hyperglycemic, 54% hypertensive, and 30% dyslipidemic. The metabolic syndrome was associated with advanced age and African-American race (P < 0.001). When adjusted for age, race, and stage, the metabolic syndrome was marginally associated with estrogen receptor-positive tumors (P = 0.054). Our findings do not support the concern that the metabolic syndrome may contribute to more biologically aggressive breast cancer.

Adiponectin ameliorates doxorubicin-induced cardiotoxicity through Akt protein-dependent mechanism

Accumulating evidence shows that obesity is associated with doxorubicin cardiac toxicity in the heart, but the molecular mechanisms that contribute to this pathological response are not understood. Adiponectin is an adipose-derived, cardioprotective factor that is down-regulated in obesity. Here, we investigated the effect of adiponectin on doxorubicin (DOX)-induced cardiotoxicity and assessed the mechanisms of this effect. A single dose of DOX was intraperitoneally injected into the abdomen of adiponectin knock-out (APN-KO) and wild-type (WT) mice. APN-KO mice had increased mortality and exacerbated contractile dysfunction of left ventricle compared with WT mice. APN-KO mice also showed increased apoptotic activity and diminished Akt signaling in the failing myocardium. Systemic delivery of adenoviral vector expressing adiponectin improved left ventricle dysfunction and myocardial apoptosis following DOX injection in WT and APN-KO mice but not in Akt1 heterozygous KO mice. In cultured rat neonatal cardiomyocytes, adiponectin stimulated Akt phosphorylation and inhibited DOX-stimulated apoptosis. Treatment with sphingosine kinase-1 inhibitor or sphingosine 1-phosphate receptor antagonist diminished adiponectin-induced Akt phosphorylation and reversed the inhibitory effects of adiponectin on myocyte apoptosis. Pretreatment with anti-calreticulin antibody reduced the binding of adiponectin to cardiac myocytes and blocked the adiponectin-stimulated increase in Akt activation and survival in cardiomyocytes. Interference of the LRP1/calreticulin co-receptor system by siRNA or blocking antibodies diminished the stimulatory actions of adiponectin on Akt activation and myocyte survival. These data show that adiponectin protects against DOX-induced cardiotoxicity by its ability to promote Akt signaling.

Preoperative chemotherapy for operable breast cancer is associated with better compliance with adjuvant therapy in matched stage II and IIIA patients

INTRODUCTION

Preoperative chemotherapy (PC) for operable breast cancer has shown significant benefits in prospective trials. Many patients are treated in the community setting and some may question the applicability of PC outside the university setting.

METHODS

Retrospective review was performed of stage II and IIIA breast cancer patients treated from January 2002 to July 2009. Fifty-three of 57 patients who underwent PC were matched based on age, tumor size, and hormone receptor status with 53 patients who did not undergo PC. Differences in patient compliance with physician recommendations for all types of adjuvant therapy were evaluated. Crude odds ratios and adjusted odds ratios derived from conditional logistic regression models were calculated.

RESULTS

There were 106 patients included. Patient compliance with chemotherapy was better in the PC group than in the adjuvant chemotherapy (AC) group (100% versus 70%; p = .0001). Similarly, more patients in the PC group completed radiation therapy (96% versus 65%; p = .0003) and initiated hormonal therapy (100% versus 62%; p = .0001). Conditional logistic regression revealed that higher pathologic stage and current cigarette smoking were associated with poorer compliance with chemotherapy. For radiation therapy, the univariate model revealed that compliance with chemotherapy and being employed were associated with completion of radiation, whereas current cigarette smoking and larger pathologic size were associated with poorer compliance with radiation. For hormonal therapy, current cigarette smokers were more likely to be noncompliant with initiation of hormonal therapy.

CONCLUSIONS

PC for operable breast cancer can improve patient compliance with chemotherapy. Current cigarette smokers were more likely to be noncompliant with all types of adjuvant therapy.

Impact of body mass index on the efficacy of endocrine therapy in premenopausal patients with breast cancer: an analysis of the prospective ABCSG-12 trial

PURPOSE

Aromatase inhibitors are effective as endocrine treatment for patients with hormone receptor-positive breast cancer. According to the hypothesis that overweight patients have higher levels of aromatase enzyme availability, we investigated the influence of body mass index (BMI) on the efficacy of adjuvant endocrine therapy in premenopausal patients in a retrospective analysis of the Austrian Breast and Colorectal Cancer Study Group (ABCSG) 12 trial.

PATIENTS AND METHODS

ABCSG-12 examined the efficacy of ovarian suppression using goserelin (3.6 mg subcutaneously every 28 days) in combination with anastrozole or tamoxifen with or without zoledronic acid (4 mg intravenously every 6 months) in premenopausal women with endocrine-responsive breast cancer. BMI was calculated using the prospectively collected data on patients' height and weight at study entry. BMI categories have been differentiated according to the WHO definition.

RESULTS

Overweight patients treated with anastrozole had a 60% increase in the risk of disease recurrence (hazard ratio [HR], 1.60; 95% CI, 1.06 to 2.41; P = .02) and more than a doubling in the risk of death (HR, 2.14; 95% CI, 1.17 to 3.92; P = .01) compared with normal weight patients treated with anastrozole. In the overweight group, patients treated with anastrozole had a nearly 50% increase in the risk of disease recurrence (HR, 1.49; 95% CI, 0.93 to 2.38; P = .08) and a three-fold increase in the risk of death (HR, 3.03; 95% CI, 1.35 to 6.82; P = .004) compared with patients treated with tamoxifen.

CONCLUSION

BMI significantly impacts on the efficacy of anastrozole plus goserelin in premenopausal patients with breast cancer, probably through influencing aromatase availability and/or ovarian suppression by goserelin.

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.

Effect of obesity on prognosis after early-stage breast cancer

PURPOSE

This study was performed to characterize the impact of obesity on the risk of breast cancer recurrence and death as a result of breast cancer or other causes in relation to adjuvant treatment.

PATIENTS AND METHODS

Information on body mass index (BMI) at diagnosis was available for 18,967 (35%) of 53,816 women treated for early-stage breast cancer in Denmark between 1977 and 2006 with complete follow-up for first events (locoregional recurrences and distant metastases) up to 10 years and for death up to 30 years. Information was available on prognostic factors and adjuvant treatment for all patients. Univariate analyses were used to compare the associations of known prognostic factors and risks of recurrence or death according to BMI categories. Cox proportional hazards regression models were used to assess the influence of BMI after adjusting for other factors.

RESULTS

Patients with a BMI of 30 kg/m(2) or more were older and had more advanced disease at diagnosis compared with patients with a BMI below 25 kg/m(2) (P < .001). When data were adjusted for disease characteristics, the risk of developing distant metastases after 10 years was significantly increased by 46%, and the risk of dying as a result of breast cancer after 30 years was significantly increased by 38% for patients with a BMI of 30 kg/m(2) or more. BMI had no influence on the risk of locoregional recurrences. Both chemotherapy and endocrine therapy seemed to be less effective after 10 or more years for patients with BMIs greater than 30 kg/m(2).

CONCLUSION

Obesity is an independent prognostic factor for developing distant metastases and for death as a result of breast cancer; the effects of adjuvant therapy seem to be lost more rapidly in patients with breast cancer and obesity.

Association between body mass index and mortality in patients with glioblastoma mutliforme

PURPOSE

To examine the association between obesity and survival in patients with glioblastoma mutliforme (GBM) METHODS: Using a prospective design, 1,259 patients with previously untreated GBM were recruited between 1991 and 2008. Height and weight were self-reported or abstracted from medical records at study entry and used to calculate body mass index (BMI) [weight (kg)/[height (m)](2). Cox proportional models were used to estimate the risk of death associated with BMI as a continuous variable or categorized using established criteria (normal weight, 18.5-24.9 kg/m(2); overweight, 25.0-29.9 kg/m(2); obese, ≥ 30.0 kg/m(2)).

RESULTS

Median follow-up was 40 months, and 1,069 (85%) deaths were observed during this period. For all patients, minimal adjusted analyses indicated no significant association between BMI treated as a continuous variable and survival. Compared with patients with a BMI 18.5-24.9 kg/m(2), the minimally adjusted HR for overall survival was 1.08 (95% CI, 0.94-1.24) for a BMI 25-29.9 kg/m(2) and 1.08 (95% CI, 0.91-28) for a BMI ≥ 30.0 kg/m(2). After additional adjustment for adjuvant therapy, the HR for those with a BMI of 25.0-29.9 kg/m(2) was 1.14 (95% CI, 0.99-1.32) and 1.09 (95% CI, 0.91-1.30) for those with a BMI ≥ 30.0 kg/m(2). No significant interactions were revealed for BMI and any demographic variables.

CONCLUSION

BMI was not associated with survival in newly diagnosed and previously untreated patients with GBM. Further research investigating the prognostic significance of alternative, quantitative measures of body habitus, and functional performance are required.

Weight, physical activity, diet, and prognosis in breast and gynecologic cancers

Diet, physical activity, and weight may affect prognosis among women who are diagnosed with breast or gynecologic cancer. Observational studies show associations between being overweight or obese and weight gain with several measures of reduced prognosis in women with breast cancer and some suggestion of poor prognosis in underweight women. Observational studies have shown an association between higher levels of physical activity and improved breast cancer-specific and all-cause mortality, although a dose-response relationship has not been established. One large randomized controlled trial reported increased disease-free survival after a mean of 5 years in patients with breast cancer randomly assigned to a low-fat diet versus control. However, another trial of similar size found no effect from a high vegetable/fruit, low-fat diet on breast cancer prognosis. The few reported studies suggest that obesity negatively affects endometrial cancer survival, while the limited data are mixed for associations of weight with ovarian cancer prognosis. Insufficient data exist for assessing associations of weight, physical activity, or diet with prognosis in other gynecologic cancers. Associations of particular micronutrient intake and alcohol use with prognosis are not defined for any of these cancers. The effects of dietary weight loss and increase in physical activity on survival or recurrence in breast and gynecologic cancers are not yet established, and randomized controlled trials are needed for definitive data.

Effect of obesity on survival of women with breast cancer: systematic review and meta-analysis

Obesity is a risk factor for the development of new cases of breast cancer and also affects survival in women who have already been diagnosed with breast cancer. Early studies of obesity and breast cancer survival have been summarised in two meta-analyses, but the latest of these only included studies that recruited women diagnosed as recently as 1991. The primary aim of this study was to conduct a meta-analysis that included the more recent studies. A systematic search of MEDLINE, EMBASE and CINAHL was conducted to identify original data evaluating the effects of obesity on survival in newly diagnosed breast cancer patients. Adjusted hazard ratios (HR) from individual studies were pooled using a random effects model. A series of pre-specified sensitivity analyses were conducted on factors such as overall versus breast cancer survival and treatment versus observational cohort. The meta-analysis included 43 studies that enrolled women diagnosed with breast cancer between 1963 and 2005. Sample size ranged from 100 to 424168 (median 1192). The meta-analysis showed poorer survival among obese compared with non-obese women with breast cancer, which was similar for overall (HR = 1.33; 95% confidence interval (CI): 1.21, 1.47) and breast cancer specific survival (HR = 1.33; 95% CI: 1.19, 1.50). The survival differential varied only slightly, depending on whether body mass index (1.33; 1.21, 1.47) or waist-hip ratio (1.31; 1.08, 1.58) was used as the measure of obesity. There were larger differences by whether the woman was pre-menopausal (1.47) or post-menopausal (1.22); whether the cohort included women diagnosed before (1.31) or after 1995 (1.49); or whether the women were in a treatment (1.22) or observational cohort (1.36), but none of the differences were statistically significant. Women with breast cancer, who are obese, have poorer survival than women with breast cancer, who are not obese. However, no study has elucidated the causal mechanism and there is currently no evidence that weight loss after diagnosis improves survival. Consequently, there is currently no reason to place the additional burden of weight loss on women already burdened with a diagnosis of cancer. Further research should concentrate on assessing whether factors such as diabetes or type of chemotherapy modify the obesity effect and on understanding the causal mechanism, in particular the role of relative under-dosing.

Interaction between menopausal status and obesity in affecting breast cancer risk

Obesity has a complex relationship to breast cancer risk that differs in premenopausal and postmenopausal women. Before the menopause, the level of adiposity is inversely related to risk, indicative of a protective effect, whereas in postmenopausal women, particularly the elderly, the association is a positive one, consistent with obesity being a risk factor. The importance of high estrogen production in adipose tissue, with consequent elevation of circulating biologically available estradiol, in the promotional effect of obesity on postmenopausal breast carcinogenesis is well established; the resulting tumors express both estrogen and progesterone receptors. The mechanism(s) for the protective effect in premenopausal women is less well understood, but the breast cancers that do develop in the presence of obesity are most often estrogen and progesterone receptor negative, consistent with the selection of non-estrogen-dependent tumor cells which are dependent on growth factors such as insulin, insulin-like growth factor-I and some adipokines. The influence of menopausal status on the relationships between adiposity and breast cancer appears to be modified within each category by age; the protective effect before the menopause may be limited to younger women (<35 years), and the adverse effect was found to apply specifically to older postmenopausal women. Although randomized trials of weight reduction for postmenopausal breast cancer prevention have not been performed, observational studies suggested that risk reduction does occur; in addition, other health benefits of weight control need to be considered regardless of menopausal status.