Pre-diagnosis body mass index and survival after breast cancer in the After Breast Cancer Pooling Project

A whole-food, plant-based randomized controlled trial in metastatic breast cancer: weight, cardiometabolic, and hormonal outcomes

PURPOSE

Breast cancer treatment is associated with weight gain, and obesity and its related cardiometabolic and hormonal risk factors have been associated with poorer outcomes. Dietary intervention may address these risk factors, but limited research has been done in the setting of metastatic breast cancer requiring systemic therapy.

METHODS

Women with metastatic breast cancer on stable treatment were randomized 2:1 to an 8-week intervention (n = 21) or control (n = 11). The intervention included weekly assessment visits and an ad libitum whole-food, plant-based (WFPB) diet with provided meals. Cardiometabolic, hormonal, and cancer markers were assessed at baseline, 4 weeks, and 8 weeks.

RESULTS

Within the intervention group, mean weight decreased by 6.6% (p < 0.01) after 8 weeks. Fasting insulin decreased from 16.8 uIU/L to 11.2 uIU/L (p < 0.01), concurrent with significantly reduced insulin resistance. Total cholesterol decreased from 193.6 mg/dL to 159 mg/dL (p < 0.01), and low-density lipoprotein (LDL) cholesterol decreased from 104.6 mg/dL to 82.2 mg/dL (p < 0.01). Total testosterone was unchanged, but free testosterone trended lower within the intervention group (p = 0.08) as sex hormone binding globulin increased from 74.3 nmol/L to 98.2 nmol/L (p < 0.01). There were no significant differences in cancer progression markers at week 8, although mean CA 15-3, CA 27.29, and CEA were lower in the intervention group (p = 0.53, p = 0.23, and p = 0.54, respectively) compared to control, when adjusted for baseline.

CONCLUSION

WFPB dietary changes during treatment for metastatic breast cancer are well tolerated and significantly improve weight, cardiometabolic and hormonal parameters. Longer studies are warranted to assess the durability of changes. Trial registration First registered at Clinicaltrials.gov (NCT03045289) on February 7, 2017.

Body adipose tissue depots and treatment outcomes for women with breast cancer: A systematic review

BACKGROUND & AIMS

Excessive adipose tissue is associated with poorer prognosis in women with breast cancer (BC). However, several body adiposity depots, such as visceral (VAT), subcutaneous (SAT), intermuscular (IMAT), and gluteofemoral adipose tissues (GFAT) may have heterogeneous metabolic roles and health effects in these patients. This systematic review aims to evaluate the impact of different body adipose tissue depots, assessed via computed tomography (CT), on treatment outcomes for women with BC. We hypothesize that distinct body adipose tissue depots may be associated differently with outcomes in patients with BC.

METHODS

A comprehensive bibliographical search was conducted using PubMed, Embase, Cochrane Library, Scopus, and Web of Science databases (until January 2024). The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

The final sample comprised 23 retrospective studies (n = 12,462), with fourteen presenting good quality. A lack of standardization in CT body adipose tissue depots measurement and outcome presentation precluded quantitative analysis. Furthermore, most included studies had heterogeneous clinical characteristics. Survival and treatment response were the most prevalent outcomes. VAT (n = 19) and SAT (n = 17) were the most frequently evaluated depots and their increase was associated with worse outcomes, mainly in terms of survival. IMAT (n = 4) presented contradictory findings and a higher GFAT (n = 1) was associated with better outcomes.

CONCLUSION

This systematic review found an association between increased VAT and SAT with worse outcomes in patients with BC. However, due to the heterogeneity of the included studies, further research with homogeneous methodologies is necessary to better understand the impact of body adipose tissue depots on treatment outcomes. Such knowledge could lead to improved care for this patient population.

The prognostic impact of BMI in patients with HR+/HER2- advanced breast cancer: a study of the SONABRE registry

PURPOSE

This study determines the prognostic impact of body mass index (BMI) in patients with hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced (i.e., metastatic) breast cancer (ABC).

METHODS

All patients with HR+/HER2- ABC who received endocrine therapy +-a cyclin-dependent kinase 4/6 inhibitor as first-given systemic therapy in 2007-2020 in the Netherlands were identified from the Southeast Netherlands Advanced Breast Cancer (SONABRE) registry (NCT03577197). Patients were categorised as underweight (BMI: < 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), or obese (≥ 30.0 kg/m2). Overall survival (OS) and progression-free survival (PFS) were compared between BMI classes using multivariable Cox regression analyses.

RESULTS

This study included 1456 patients, of whom 35 (2%) were underweight, 580 (40%) normal weight, 479 (33%) overweight, and 362 (25%) obese. No differences in OS were observed between normal weight patients and respectively overweight (HR 0.99; 95% CI 0.85-1.16; p = 0.93) and obese patients (HR 1.04; 95% CI 0.88-1.24; p = 0.62). However, the OS of underweight patients (HR 1.45; 95% CI 0.97-2.15; p = 0.07) tended to be worse than the OS of normal weight patients. When compared with normal weight patients, the PFS was similar in underweight (HR 1.05; 95% CI 0.73-1.51; p = 0.81), overweight (HR 0.90; 95% CI 0.79-1.03; p = 0.14), and obese patients (HR 0.88; 95% CI 0.76-1.02; p = 0.10).

CONCLUSION

In this study among 1456 patients with HR+/HER2- ABC, overweight and obesity were prevalent, whereas underweight was uncommon. When compared with normal weight, overweight and obesity were not associated with either OS or PFS. However, underweight seemed to be an adverse prognostic factor for OS.

A Whole-Food, Plant-Based Randomized Controlled Trial in Metastatic Breast Cancer: Weight, Cardiometabolic, and Hormonal Outcome

Purpose

Breast cancer treatment is associated with weight gain, and obesity and its related cardiometabolic and hormonal risk factors have been associated with poorer outcomes. Dietary intervention may address these risk factors, but limited research has been done in the setting of metastatic breast cancer requiring systemic therapy.

Methods

Women with metastatic breast cancer on stable treatment were randomized 2:1 to an 8-week intervention (n = 21) or control (n = 11). The intervention included weekly assessment visits and an ad libitum whole food, plant-based (WFPB) diet with provided meals. Cardiometabolic, hormonal, and cancer markers were assessed at baseline, 4 weeks, and 8 weeks.

Results

Within the intervention group, mean weight decreased by 6.6% (p < 0.01) after 8 weeks. Fasting insulin decreased from 16.8 uIU/L to 11.2 uIU/L (p < 0.01), concurrent with significantly reduced insulin resistance. Total cholesterol decreased from 193.6 mg/dL to 159 mg/dL (p < 0.01) and low-density lipoprotein (LDL) cholesterol decreased from 104.6 mg/dL to 82.2 mg/dL (p < 0.01). Total testosterone was unchanged, but free testosterone trended lower within the intervention group (p = 0.08) as sex hormone binding globulin increased from 74.3 nmol/L to 98.2 nmol/L (p < 0.01). There were no significant differences in cancer progression markers at week 8, although mean CA 15 - 3, CA 27.29, and CEA were lower in the intervention group (p = 0.53, p = 0.23, and p = 0.54, respectively) compared to control, when adjusted for baseline.

Conclusion

WFPB dietary changes during treatment for metastatic breast cancer are well tolerated and significantly improve weight and cardiometabolic and hormonal parameters. Longer studies are warranted to assess the durability of changes.

Trial registration

First registered at Clinicaltrials.gov (NCT03045289) on February 7, 2017.

Association of body composition and surgical outcomes in patients with early-stage breast cancer

BACKGROUND

Breast cancer is a disease that requires multimodality treatment, and surgical resection of the tumor is a critical component of curative intent treatment. Obesity, defined as a body mass index (BMI) > 30, has been associated with increased surgical complications. Additionally, sarcopenia, a condition of gradual loss of muscle mass, has been associated with worse breast cancer treatment outcomes. Sarcopenia occurs with increased age, inactivity, and poor diet leading to patient frailty, which can increase medical treatment complications. Even patients with high BMI can have sarcopenia (termed sarcopenic obesity). We investigated the association of sarcopenia with surgical complications for breast cancer.

METHODS

A retrospective review was performed of patients diagnosed with breast cancer who received bioelectrical impedance spectrometry analysis of skeletal muscle mass and had surgery at our institution. Patient characteristics, treatment data, surgical type and complications were obtained from medical records. Multivariate logistic regression models were used to associate sarcopenia status and BMI with surgical complications, adjusted for other patient characteristics.

RESULTS

We analyzed 682 patients with stage I to III breast cancer. On multivariable logistic regression controlling for age, BMI, comorbidities, and types of surgeries (lumpectomy, mastectomy with or without reconstruction), sarcopenia (p = 0.66) was not associated with surgical complications. Obesity was associated with a higher rate of surgical complications in patients who received mastectomy with reconstruction (p = 0.01). More complex surgical approaches were associated with a higher risk of surgical complications in our series.

CONCLUSION

Compared with those undergoing lumpectomy or mastectomy without reconstruction, patients undergoing mastectomy with reconstruction were more likely to experience postoperative complications and obesity was associated with higher risk of complication in the latter group. We did not identify a correlation between sarcopenia and rate of adverse surgical outcomes.

Diet and physical activity interventions in Black and Latina women with breast cancer: A scoping review

Background

A growing number of lifestyle interventions are being developed to promote weight loss and adoption of a healthful lifestyles among breast cancer survivors; yet Black and Latina women remain underrepresented.

Purpose

We performed a scoping review of the available peer-reviewed literature to describe and compare the content, design, methods, and primary outcomes of current diet and/or physical activity (PA) interventions after a breast cancer diagnosis among Black and Latina women.

Methods

We queried PubMed, EMBASE, CINAHL, MEDLINE, and Clinicaltrials.gov up to October 1, 2022, to identify all randomized controlled trials of diet and/or PA after diagnosis of breast cancer with a majority (&gt;50%) of Black or Latina participants.

Results

Twenty-two randomized controlled trials were included in this review (five efficacy, twelve pilot, five on-going). Nine trials were among Latinas (two diet, four PA, and three diet/PA), six among Blacks (one PA and five diet/PA) and seven included both populations (five PA and two diet/PA), all of which examined different endpoints. Two of the five efficacy studies achieved their a priori outcome (one diet trial improved short term dietary intake; one PA trial achieved clinically significant improvements in metabolic syndrome score), both in Latinas. Eight pilot trials intervened on both diet and PA and three of them found favorable behavioral changes. Three (two for Latinas and one for Blacks) out of the nine diet and PA trials and three (all for Latinas) efficacy trials incorporated a culturally focused approach (i.e., traditional foods, music, Spanish content, bicultural health coaches, spirituality). Overall, four trials, including one efficacy trial, had one-year follow-up data, with three finding sustained behavior change. Electronic/mobile components were incorporated in five trials and one involved informal care givers. Most of the trials were geographically limited to the Northeast USA (n=8, NY, NC, DC, NJ) and Texas (n=4).

Conclusions

Most of the trials we identified were pilot or feasibility studies and of short duration, demonstrating the need for large randomized controlled efficacy lifestyle interventions among Black and Latina breast cancer survivors. Culturally tailored programing was limited but is an important component to incorporate in future trials in these populations.

Rat Mammary carcinoma susceptibility 3 (Mcs3) pleiotropy, socioenvironmental interaction, and comparative genomics with orthologous human 15q25.1-25.2

Genome-wide association studies of breast cancer susceptibility have revealed risk-associated genetic variants and nominated candidate genes; however, the identification of causal variants and genes is often undetermined by genome-wide association studies. Comparative genomics, utilizing Rattus norvegicus strains differing in susceptibility to mammary tumor development, is a complimentary approach to identify breast cancer susceptibility genes. Mammary carcinoma susceptibility 3 (Mcs3) is a Copenhagen (COP/NHsd) allele that confers resistance to mammary carcinomas when introgressed into a mammary carcinoma susceptible Wistar Furth (WF/NHsd) genome. Here, Mcs3 was positionally mapped to a 7.2-Mb region of RNO1 spanning rs8149408 to rs107402736 (chr1:143700228-150929594, build 6.0/rn6) using WF.COP congenic strains and 7,12-dimethylbenz(a)anthracene-induced mammary carcinogenesis. Male and female WF.COP-Mcs3 rats had significantly lower body mass compared to the Wistar Furth strain. The effect on female body mass was observed only when females were raised in the absence of males indicating a socioenvironmental interaction. Furthermore, female WF.COP-Mcs3 rats, raised in the absence of males, did not develop enhanced lobuloalveolar morphologies compared to those observed in the Wistar Furth strain. Human 15q25.1-25.2 was determined to be orthologous to rat Mcs3 (chr15:80005820-82285404 and chr15:83134545-84130720, build GRCh38/hg38). A public database search of 15q25.1-25.2 revealed genome-wide significant and nominally significant associations for body mass traits and breast cancer risk. These results support the existence of a breast cancer risk-associated allele at human 15q25.1-25.2 and warrant ultrafine mapping of rat Mcs3 and human 15q25.1-25.2 to discover novel causal genes and variants.

Proton Pump Inhibitor Use and Obesity-Associated Cancer in the Women's Health Initiative

Proton pump inhibitors (PPIs) have off-target activity on fatty acid synthase (FASN), a critical enzyme in energy balance and cancer growth. We evaluated risk of common obesity-related cancers: breast, colorectal (CRC), and endometrial, with use of PPI and histamine-2 receptor antagonists (H2RA) in 124,931 postmenopausal women enrolled in the Women's Health Initiative. Incident cancer cases were physician-adjudicated. Cox proportional hazards models were used to estimate multivariable hazard ratios (HR) and 95% confidence intervals (CI) for cancer incidence after year 3. There were 7956 PPI ever users and 9398 H2RA only users. Ever use of either PPI or H2RA was not associated with risk of breast cancer (n = 9186) nor risk of endometrial cancer (n = 1231). The risk of CRC (n = 2280) was significantly lower in PPI users (HR = 0.75, 95% CI = 0.61-0.92), but not in H2RA users (HR = 1.13, 95% CI = 0.97-1.31). The association of PPI use with CRC was apparent regardless of BMI or NSAID use, and was stronger with longer PPI duration (p = 0.006) and potency (p = 0.005). The findings that PPI use, but not H2RA use, demonstrate an inverse dose-response relationship with risk of CRC is consistent with preclinical data showing FASN inhibition prevents colon cancer progression and supports a role of PPI in CRC prevention.

Body mass index increases the recurrence risk of breast cancer: a dose-response meta-analysis from 21 prospective cohort studies

OBJECTIVE

The purpose of this study was to investigate the effect of body mass index (BMI) on the recurrence risk of breast cancer.

STUDY DESIGN

Dose-response meta-analysis.

METHODS

Cohort studies that included BMI and the recurrence of breast cancer were selected through various databases including PubMed, Web of Science, the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP), and Wanfang Data Knowledge Service Platform (WanFang) until November 30, 2021. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of literature. A two-stage random-effects meta-analysis was performed to assess the dose-response relationship between BMI and breast cancer recurrence risk. Heterogeneity between studies is assessed using I².

RESULTS

The relative risk (RR) of BMI <25 kg/m² vs BMI ≥25 kg/m², BMI <30 kg/m² vs BMI ≥30 kg/m² were 1.09 (95% CI: 1.00-1.19) and 1.15 (95% CI: 1.04-1.27), suggesting that BMI had a significant effect on the recurrence risk of breast cancer, and there might be a dose-response relationship between them. A total of 21 studies were included in dose-response meta-analysis, which showed that there was a positive linear correlation between BMI and the risk of recurrence (RR = 1.02, 95% CI: 1.01-1.03). For every 1 kg/m² increment of BMI, the risk of recurrence increased by approximately 2%. In subgroup analyses, positive linear dose-response relationships between BMI and recurrence risk were observed among Asian and study period >10 years groups. For every 1 kg/m² increment of BMI, the risk of recurrence increased by 3.41% and 1.87%, respectively.

CONCLUSIONS

The recurrence risk of breast cancer increases with BMI, which is most obvious among Asian women.

Associations of adiposity and weight change with recurrence and survival in breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Adiposity and weight change among patients with breast cancer are associated with mortality, but there is limited evidence on the associations with distant recurrence or other causes of death or on central adiposity. Moreover, the relationship with breast cancer subtypes and by menopause status is unclear.

METHODS

We conducted a systematic review and meta-analysis of prospective studies of breast cancer patients investigating the associations of general and central adiposity (body mass index [BMI] and waist circumference [WC], respectively), before and after diagnosis, and weight change, with all-cause mortality, breast cancer-specific mortality (BCSM), and recurrence.

RESULTS

173 studies (519,544 patients, 60,249 deaths overall, and 25,751 breast cancer deaths) were included. For BMI  < 1 year post diagnosis, compared with normal weight women, the summary relative risk (RR) for obese women was 1.21 (1.15-1.27) for all-cause mortality, 1.22 (1.13-1.32) for BCSM, 1.12 (1.06-1.18) for recurrence, and 1.19 (1.11-1.28) for distant recurrence. Obesity was associated with all-cause mortality and BCSM in patients with ER+ or HER2+ tumors, whereas no clear association was observed in patients with triple-negative tumors. Similar associations were observed by menopausal status. Stronger associations were observed in East Asians than Europeans. Central adiposity was associated with all-cause mortality, while large weight gain was associated with all-cause mortality, BCSM, and recurrence.

CONCLUSION

Higher adiposity is associated with all-cause mortality, BCSM, recurrence, and distant recurrence in breast cancer patients, with similar associations by menopausal status and some evidence of heterogeneity by subtypes. Weight gain is also associated with recurrence and survival among breast cancer patients.

Advances in the Prevention and Treatment of Obesity-Driven Effects in Breast Cancers

Obesity and associated chronic inflammation were shown to facilitate breast cancer (BC) growth and metastasis. Leptin, adiponectin, estrogen, and several pro-inflammatory cytokines are involved in the development of obesity-driven BC through the activation of multiple oncogenic and pro-inflammatory pathways. The aim of this study was to assess the reported mechanisms of obesity-induced breast carcinogenesis and effectiveness of conventional and complementary BC therapies. We screened published original articles, reviews, and meta-analyses that addressed the involvement of obesity-related signaling mechanisms in BC development, BC treatment/prevention approaches, and posttreatment complications. PubMed, Medline, eMedicine, National Library of Medicine (NLM), and ReleMed databases were used to retrieve relevant studies using a set of keywords, including "obesity," "oncogenic signaling pathways," "inflammation," "surgery," "radiotherapy," "conventional therapies," and "diet." Multiple studies indicated that effective BC treatment requires the involvement of diet- and exercise-based approaches in obese postmenopausal women. Furthermore, active lifestyle and diet-related interventions improved the patients' overall quality of life and minimized adverse side effects after traditional BC treatment, including postsurgical lymphedema, post-chemo nausea, vomiting, and fatigue. Further investigation of beneficial effects of diet and physical activity may help improve obesity-linked cancer therapies.

Impact of cumulative body mass index and cardiometabolic diseases on survival among patients with colorectal and breast cancer: a multi-centre cohort study

BACKGROUND

Body mass index (BMI) and cardiometabolic comorbidities such as cardiovascular disease and type 2 diabetes have been studied as negative prognostic factors in cancer survival, but possible dependencies in the mechanisms underlying these associations remain largely unexplored. We analysed these associations in colorectal and breast cancer patients.

METHODS

Based on repeated BMI assessments of cancer-free participants from four European countries in the European Prospective Investigation into Cancer and nutrition (EPIC) study, individual BMI-trajectories reflecting predicted mean BMI between ages 20 to 50 years were estimated using a growth curve model. Participants with incident colorectal or breast cancer after the age of 50 years were included in the survival analysis to study the prognostic effect of mean BMI and cardiometabolic diseases (CMD) prior to cancer. CMD were defined as one or more chronic conditions among stroke, myocardial infarction, and type 2 diabetes. Hazard ratios (HRs) and confidence intervals (CIs) of mean BMI and CMD were derived using multivariable-adjusted Cox proportional hazard regression for mean BMI and CMD separately and both exposures combined, in subgroups of localised and advanced disease.

RESULTS

In the total cohort of 159,045 participants, there were 1,045 and 1,620 eligible patients of colorectal and breast cancer. In colorectal cancer patients, a higher BMI (by 1 kg/m2) was associated with a 6% increase in risk of death (95% CI of HR: 1.02-1.10). The HR for CMD was 1.25 (95% CI: 0.97-1.61). The associations for both exposures were stronger in patients with localised colorectal cancer. In breast cancer patients, a higher BMI was associated with a 4% increase in risk of death (95% CI: 1.00-1.08). CMDs were associated with a 46% increase in risk of death (95% CI: 1.01-2.09). The estimates and CIs for BMI remained similar after adjustment for CMD and vice versa.

CONCLUSIONS

Our results suggest that cumulative exposure to higher BMI during early to mid-adulthood was associated with poorer survival in patients with breast and colorectal cancer, independent of CMD prior to cancer diagnosis. The association between a CMD diagnosis prior to cancer and survival in patients with breast and colorectal cancer was independent of BMI.

Skeletal muscle loss during neoadjuvant chemotherapy predicts poor prognosis in patients with breast cancer

Background

The skeletal muscle index (SMI), which is calculated as the ratio of skeletal muscle area at the third lumbar vertebral level divided by height squared, has been considered a prognostic factor in patients with breast cancer. However, the prognostic impact of changes in SMI during treatment remains unclear. This study aimed to evaluate the influence of SMI changes in patients with breast cancer undergoing neoadjuvant chemotherapy (NAC).

Methods

We reviewed patients with breast cancer who underwent NAC and subsequent surgery for breast cancer between 2010 and 2017. The rate of SMI change during NAC was calculated, and the association between SMI changes and prognosis was retrospectively analyzed.

Results

In total, 141 patients were evaluated. 48 (34.0%), 53 (37.6%), and 40 (28.4%) patients exhibited increased (≥ 3%), maintained (− 3% <, < 3%), and decreased (− 3% ≥) SMI during NAC, respectively. The decreased SMI group showed significantly poorer disease-free survival than the maintained and increased SMI groups (hazard ratio [HR] 8.29, p <  0.001 for the decreased vs. increased SMI groups; HR 3.49, p <  0.001 for the decreased vs. maintained SMI groups). Moreover, decreased SMI was an independent risk factor for disease-free survival in multivariate analysis (HR 3.68, p <  0.01).

Conclusions

Skeletal muscle loss during NAC predicts poor prognosis. Our results underscore the importance of monitoring and maintaining skeletal muscle mass during NAC.

Impact of Skeletal Muscle Loss and Visceral Obesity Measured Using Serial CT on the Prognosis of Operable Breast Cancers in Asian Patients

Objective

This study aimed to investigate the impact of baseline values and temporal changes in body composition parameters, including skeletal muscle index (SMI) and visceral adipose tissue area (VAT), measured using serial computed tomography (CT) imaging on the prognosis of operable breast cancers in Asian patients.

Materials and Methods

This study retrospectively included 627 Asian female (mean age ± standard deviation [SD], 53.6 ± 8.3 years) who underwent surgery for stage I–III breast cancer between January 2011 and September 2012. Body composition parameters, including SMI and VAT, were semi-automatically calculated on baseline abdominal CT at the time of diagnosis and follow-up CT for post-treatment surveillance. Serial changes in SMI and VAT were calculated as the delta values. Multivariable Cox regression analysis was used to evaluate the association of baseline and delta SMI and VAT values with disease-free survival.

Results

Among 627 patients, 56 patients (9.2%) had breast cancer recurrence after a median of 40.5 months. The mean value ± SD of the baseline SMI and baseline VAT were 43.7 ± 5.8 cm²/m² and 72.0 ± 46.0 cm², respectively. The mean value of the delta SMI was -0.9 cm²/m² and the delta VAT was 0.5 cm². The baseline SMI and VAT were not significantly associated with disease-free survival (adjusted hazard ratio [HR], 0.983; 95% confidence interval [CI], 0.937–1.031; p = 0.475 and adjusted HR, 1.001; 95% CI, 0.995–1.006; p = 0.751, respectively). The delta SMI and VAT were also not significantly associated with disease-free survival (adjusted HR, 0.894; 95% CI, 0.766–1.043; p = 0.155 and adjusted HR, 1.001; 95% CI, 0.989–1.014; p = 0.848, respectively).

Conclusion

Our study revealed that baseline and early temporal changes in SMI and VAT were not independent prognostic factors regarding disease-free survival in Asian patients undergoing surgery for breast cancer.

Bariatric surgery in patients with breast and endometrial cancer in California: population-based prevalence and survival

BACKGROUND

The number of bariatric surgeries performed in the United States has increased substantially since the 1990's. However, the prevalence and prognostic impact of bariatric surgery, or weight loss surgery (WLS), among patients with cancer are not known.

OBJECTIVES

We investigated the population-based prevalence of WLS in women with breast or endometrial cancer and conducted exploratory analysis to examine whether postdiagnosis WLS is associated with survival.

SETTING

Administrative statewide database.

METHODS

WLS records for women with nonmetastasized breast (n = 395,146) or endometrial (n = 69,859) cancer were identified from the 1991-2014 California Cancer Registry data linked with the California Office of Statewide Health Planning and Development database. Characteristics of the patients were examined according to history of WLS. Using body mass index data available since 2011, a retrospective cohort of patients with breast or endometrial cancer and obesity (n = 12,540) was established and followed until 2017 (5% lost to follow-up). Multivariable cause-specific Cox proportional hazards models were used to examine the associations between postdiagnostic WLS and time to death.

RESULTS

WLS records were identified for 2844 (.7%) patients with breast cancer and 1140 (1.6%) patients with endometrial cancer; about half of the surgeries were performed after cancer diagnosis. Postdiagnosis WLS was performed in ∼1% of patients with obesity and was associated with a decreased hazard for death (cause-specific hazard ratio = .37; 95% confidence interval = .014-.99; P = .049), adjusting for age, stage, co-morbidity, race/ethnicity, and socioeconomic status.

CONCLUSION

About 2000 patients with breast or endometrial cancer in California underwent post-diagnosis WLS between 1991 and 2014. Our data support survival benefits of WLS after breast and endometrial cancer diagnosis.

Fish oil supplementation increases expression of mammary tumor apoptosis mediators and reduces inflammation in an obesity-associated HER-2 breast cancer model

Obesity is associated with inflammation and has been shown to increase breast cancer severity. The objective of this study was to examine the effect of fish oil (FO) supplementation in obesity-associated mammary tumorigenesis in the MMTV-neu(ndl)-YD5 mouse model of human epidermal growth factor receptor-2 positive BC. Female mice were fed one of three diets for 16 weeks: i) high fat diet [HF, % kacl: 41.2% lard, 18.7% corn oil (CO)], ii) an isocaloric HF plus menhaden FO diet (HF+FO, % kcal: 41.2 lard, 13.4% CO, 5.3% FO), iii) low fat diet (LF, % kcal: 4.7% lard, 6% CO). HF mice had increased body weight, visceral adipose weight and serum hormone concentrations (increased leptin and resistin; decreased adiponectin) versus LF, which was attenuated in the HF+FO group versus HF (P<.05). Compared to HF, tumor onset was delayed in HF+FO and LF mice (P<0.05). Compared to HF, HF+FO reduced mammary tumor multiplicity (-27%), tumor weight (-46%) and total tumor volume (-50%) (P<0.05). Additionally, HF+FO reduced mammary tumor multiplicity (-33%), tumor weight (-39%) and total tumor volume (-60%) versus LF. HF+FO improved mammary tumor apoptosis status with increased expression of pro-apoptotic Bad and decreased expression of anti-apoptotic Bcl-xLmediators versus HF (P<0.05). Additionally, HF+FO decreased tumor protein expression of activated Akt, NFκB p65 and STAT3, versus HF (P<0.05). Tumor mRNA expression of inflammatory mediators TNFα, IL-6 and leptin were reduced in HF+FO, whereas IL-10 expression was increased compared to HF (P<0.05). Collectively these results demonstrate the efficacy of FO supplementation for improving obesity-associated 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.

A standardized, integral nutritional intervention and physical activity program reduces body weight in women newly diagnosed with breast cancer

Introduction

Introduction: breast cancer is the most common invasive cancer among women in developed countries. At diagnosis, approximately 70 % of women are overweight, and the additional weight gain that can result from the ensuing treatments has been associated with cancer recurrence and progression. Objectives: the main objective was to compare the effect of only a nutritional intervention (CG) with a nutrition education program (nutritional intervention, nutrition education, and physical activity) (IG) for 1 year. Methods: a total of 65 women with breast cancer who had been evaluated at the Clinical Nutrition Department, La Paz University Hospital, Madrid, Spain were recruited into 2 groups: a control group (CG) and an intervention group (IG). Results: the IG showed a significant reduction in body weight (-1.87 ± 3.41 vs. 1.48 ± 2.01 kg, p < 0.05), BMI (-0.61 ± 1.40 vs. 0.65 ± 0.88 kg/m2, p < 0.05), total cholesterol (-32.92 ± 38.45 vs. -3.23 ± 39.73 mg/dl, p < 0.05), and low-density lipoprotein cholesterol (-35.29 ± 27.50 vs. 6.33 ± 40.70 mg/dl, p < 0.05). Both groups were shown to be more conscious of the importance of physical activity, with increased consumption of grains, fruits, oily fish, and dairy. Conclusions: dietary interventions and physical activity were shown to be important to achieving several physical and physiological benefits that could reduce some risk factors associated with breast cancer recurrence and progression.

Racial/Ethnic Disparities in Survival after Breast Cancer Diagnosis by Estrogen and Progesterone Receptor Status: A Pooled Analysis

BACKGROUND

Limited studies have investigated racial/ethnic survival disparities for breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status in a multiethnic population.

METHODS

Using multivariable Cox proportional hazards models, we assessed associations of race/ethnicity with ER/PR-specific breast cancer mortality in 10,366 California women diagnosed with breast cancer from 1993 to 2009. We evaluated joint associations of race/ethnicity, health care, sociodemographic, and lifestyle factors with mortality.

RESULTS

Among women with ER/PR⁺ breast cancer, breast cancer-specific mortality was similar among Hispanic and Asian American women, but higher among African American women [HR, 1.31; 95% confidence interval (CI), 1.05-1.63] compared with non-Hispanic White (NHW) women. Breast cancer-specific mortality was modified by surgery type, hospital type, education, neighborhood socioeconomic status (SES), smoking history, and alcohol consumption. Among African American women, breast cancer-specific mortality was higher among those treated at nonaccredited hospitals (HR, 1.57; 95% CI, 1.21-2.04) and those from lower SES neighborhoods (HR, 1.48; 95% CI, 1.16-1.88) compared with NHW women without these characteristics. Breast cancer-specific mortality was higher among African American women with at least some college education (HR, 1.42; 95% CI, 1.11-1.82) compared with NHW women with similar education. For ER^-/PR^- disease, breast cancer-specific mortality did not differ by race/ethnicity and associations of race/ethnicity with breast cancer-specific mortality varied only by neighborhood SES among African American women.

CONCLUSIONS

Racial/ethnic survival disparities are more striking for ER/PR⁺ than ER^-/PR^- breast cancer. Social determinants and lifestyle factors may explain some of the survival disparities for ER/PR⁺ breast cancer.

IMPACT

Addressing these factors may help reduce the higher mortality of African American women with ER/PR⁺ breast cancer.

Factors Affecting Onset and Persistence of Metabolic Syndrome in Korean Breast Cancer Survivors: A Prospective Study

This study aimed to investigate the onset and persistence of metabolic syndrome in breast cancer survivors in a community setting. The study included 329 female breast cancer survivors from 39 community health examination centers located in 14 urban areas in Korea. After an average of 4.6 years of follow-up, based on the presence of metabolic syndrome at baseline and follow-up, the subjects were assigned to three groups: Non-metabolic syndrome (n = 249), onset (n = 32), and persistent (n = 48). Factors associated with the metabolic syndrome were analyzed and presented as odds ratios (ORs). Older age, postmenopausal status, lower education, and lower-income level were associated with an increased prevalence of metabolic syndrome in the onset Mets and persistent Mets group. In particular, when the breast cancer survivor was obese (≥25 kg/m²), the probability of developing metabolic syndrome was 3.33 times higher than normal-weight subjects (<23 kg/m²) and the probability of metabolic syndrome persisting was 16.34 times. When breast cancer survivors were in their 60s or older, the probability of metabolic syndrome persisting was 4.27 times higher than those in their 40s. To prevent the onset and persistence of metabolic syndrome in breast cancer survivors, health-care providers should identify risk factors. Obesity, in particular, should be controlled.

Sarcopenia as a risk factor of severe laboratory adverse events in breast cancer patients receiving perioperative epirubicin plus cyclophosphamide therapy

PURPOSE

Sarcopenia has been reported to be associated with higher mortality and increased toxicity of chemotherapy in breast cancer patients. However, evidence from Asian countries is scarce. Here, we investigated the association between sarcopenia and the frequency of severe laboratory adverse events due to perioperative chemotherapy in Japanese breast cancer patients.

METHODS

Eighty-two patients with breast cancer receiving perioperative epirubicin plus cyclophosphamide therapy were evaluated. Skeletal muscle of the cross-sectional area at the third lumbar vertebra was measured by computed tomography, and sarcopenia was defined as skeletal muscle index < 40 cm²/m². Laboratory toxicity during all cycles of perioperative chemotherapy was assessed. The study endpoint was the frequency of severe (grade 3 or more) laboratory adverse events.

RESULTS

Overall, 10 patients (12.2%) were classified as sarcopenic. The frequency of severe laboratory adverse events was 28.0%, and this was significantly higher in sarcopenic patients compared to non-sarcopenic patients (70% vs. 22.2%, odds ratio 7.9 (95% CI, 1.6-52.8), p = 0.004). Neither of body weight, body mass index, area of visceral adipose tissue, subcutaneous adipose tissue, nor skeletal muscle density was significantly associated with the frequency of severe laboratory adverse events.

CONCLUSION

Sarcopenia was a significant risk factor of severe laboratory toxicity in breast cancer patients receiving perioperative epirubicin plus cyclophosphamide therapy. This finding raises the potential use of body composition assessment to predict the risk of chemotherapy toxicity and determine an individualized treatment strategy.

Aberrant Zip14 expression in muscle is associated with cachexia in a Bard1-deficient mouse model of breast cancer metastasis

Nearly 80% of advanced cancer patients are afflicted with cachexia, a debilitating syndrome characterized by extensive loss of muscle mass and function. Cachectic cancer patients have a reduced tolerance to antineoplastic therapies and often succumb to premature death from the wasting of respiratory and cardiac muscles. Since there are no available treatments for cachexia, it is imperative to understand the mechanisms that drive cachexia in order to devise effective strategies to treat it. Although 25% of metastatic breast cancer patients develop symptoms of muscle wasting, mechanistic studies of breast cancer cachexia have been hampered by a lack of experimental models. Using tumor cells deficient for BARD1, a subunit of the BRCA1/BARD1 tumor suppressor complex, we have developed a new orthotopic model of triple‐negative breast cancer that spontaneously metastasizes to the lung and leads to systemic muscle deterioration. We show that expression of the metal‐ion transporter, Zip14, is markedly upregulated in cachectic muscles from these mice and is associated with elevated intramuscular zinc and iron levels. Aberrant Zip14 expression and altered metal‐ion homeostasis could therefore represent an underlying mechanism of cachexia development in human patients with triple‐negative breast cancer. Our study provides a unique model for studying breast cancer cachexia and identifies a potential therapeutic target for its treatment.

Association of Muscle and Adiposity Measured by Computed Tomography With Survival in Patients With Nonmetastatic Breast Cancer

Importance

Sarcopenia (low muscle mass), poor muscle quality (low muscle radiodensity), and excess adiposity derived from computed tomography (CT) has been related to higher mortality in patients with metastatic breast cancer, but the association with prognosis in patients with nonmetastatic breast cancer is unknown.

Objective

To evaluate associations of all 3 body composition measures, derived from clinically acquired CT at diagnosis, with overall mortality in nonmetastatic breast cancer.

Design, Setting, and Participants

This observational study included 3241 women from Kaiser Permanente of Northern California and Dana Farber Cancer Institute diagnosed from January 2000 to December 2013 with stages II or III breast cancer. We calculated hazard ratios (HRs) to evaluate the associations of all-cause mortality with sarcopenia, low muscle radiodensity, and total adipose tissue (TAT). Models were adjusted for sociodemographics, tumor characteristics, treatment, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and other body composition measures. We also evaluated the cross-classification of categories of sarcopenia (yes/no) and tertiles of TAT, with outcomes.

Main Outcomes and Measures

Overall survival time and all-cause mortality.

Results

Median (range) age of 3241 women included in this study was 54 (18-80) years, and median follow-up was 6.0 years; 1086 patients (34%) presented with sarcopenia, and 1199 patients (37%) had low muscle radiodensity. Among patients with nonmetastatic breast cancer, those with sarcopenia showed higher overall mortality (HR, 1.41; 95% CI, 1.18-1.69) compared with those without sarcopenia. Patients in the highest tertile of TAT also showed higher overall mortality (HR, 1.35; 95% CI, 1.08-1.69) compared with those in the lowest tertile. Low radiodensity was not associated with survival. In analyses of sarcopenia and TAT, highest mortality was seen in patients with sarcopenia and high TAT (HR, 1.89; 95% CI, 1.30-2.73); BMI alone was not significantly related to overall mortality and did not appropriately identify patients at risk of death owing to their body composition.

Conclusions and Relevance

Sarcopenia is underrecognized in nonmetastatic breast cancer and occurs in over one-third of newly diagnosed patients. Measures of both sarcopenia and adiposity from clinically acquired CT scans in nonmetastatic patients provide significant prognostic information that outperform BMI and will help to guide interventions to optimize survival outcomes.

Prognostic Significance of Abdominal-to-Gluteofemoral Adipose Tissue Distribution in Patients with Breast Cancer

This study aimed to evaluate the association between abdominal-to-gluteofemoral adipose tissue (AT) distribution and recurrence-free survival (RFS) in breast cancer patients. Staging F-18 fluorodexoyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images of 336 women with breast cancer were retrospectively analyzed. From CT images, the volume and CT-attenuation of visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (SAT), and gluteofemoral AT were measured and the ratio of abdomen-to-gluteofemoral AT volume (AG volume ratio) was calculated. The relationships between adipose tissue parameters and RFS were assessed. Through univariate analysis, abdominal SAT volume, gluteofemoral AT volume, and AG volume ratio were significantly associated with RFS. An increase in abdominal SAT volume and AG volume ratio were associated with an increased risk of recurrence, whereas increased gluteofemoral AT volume was associated with a decreased risk of recurrence. On multivariate analysis, abdominal SAT volume, gluteofemoral AT volume, and AG volume ratio were found to be significant predictors of RFS after adjusting for clinic-histological factors. Irrespective of obesity, patients with a high AG volume ratio showed a higher recurrence rate than those with a low AG volume ratio. Increased abdominal SAT volume and decreased gluteofemoral AT volume were related to poor RFS in breast cancer patients.

The Importance of Body Composition in Explaining the Overweight Paradox in Cancer-Counterpoint

Despite a greater risk of cancer associated with higher BMI, overweight (BMI 25-<30 kg/m²) and class I obese (BMI 30-<35 kg/m²) patients often have a paradoxically lower risk of overall mortality after a cancer diagnosis, a phenomenon called the "obesity paradox." Only when patients exceed a BMI ≥35 kg/m² are elevations in mortality risk consistently noted. This paradox has been dismissed as the result of methodologic bias, which we will describe and debate here. However, even if such bias influences associations, there is growing evidence that body composition may in part explain the paradox. This phenomenon may more accurately be described as a BMI paradox. That is, BMI is a poor proxy for adiposity and does not distinguish muscle from adipose tissue, nor describe adipose tissue distribution. Low muscle mass is associated with higher risk of recurrence, overall and cancer-specific mortality, surgical complications, and treatment-related toxicities. Patients with who are overweight or obese have on average higher levels of muscle than their normal-weight counterparts. Also, there is some evidence that patients with moderate levels of subcutaneous adipose tissue may have lower mortality. More research utilizing body composition is needed to clarify the effects of adiposity on cancer mortality. Cancer Res; 78(8); 1906-12. ©2018 AACR.

[Obesity and Cancer]

In the past decades, obesity and overweight prevalence has been rising worldwide, in both men and women. In France, the prevalence of overweight in adults was 49% in 2015 (54% among men and 44% among women), including 17% of obese adults. According to the last evaluation performed by IARC in 2017, overweight and obesity are established risk factors for 13 cancer sites with risk estimates per 5kg/m2 varying largely depending on the cancer site. In 2015 in France, 5.4% of cancer cases could be attributed to excess weight, corresponding to 18,600 cases, including 3400 colon cancers, 2600 kidney cancers, 4500 breast cancers and 2500 endometrial cancers. Obesity is also related to worse prognosis for some cancers, in particular breast and colon cancers. Obesity in children and adolescents, also rising in many countries, has also been associated to an increase in adult cancer risk. A major cause of obesity is a disequilibrium in energy balance favoured by a diet rich in processed food, red meat, trans and saturated fatty acids, sweetened foods and beverages and poor in fruits and vegetables, legumes and whole grains. Main national and international recommendations to reduce the prevalence of obesity are to have a balanced diet and regular physical activity.

Adherence to adjuvant endocrine therapy in postmenopausal breast cancer patients: A 5-year prospective study

PURPOSE

Adjuvant endocrine therapy (ET) in breast cancer reduces recurrence risk and increases overall survival. The aim of the study was to quantify non-adherence and discontinuation to ET in postmenopausal women with breast cancer, and identify possible clinical or social risk factors.

METHODS

Women with hormone-receptor positive breast cancer (N = 138), mean age 58 (SD 9.3) years, filled in 4 questionnaires within 1-12, 24, 36 and 48-60 months after surgery; Subjective Health Complaints Inventory (SHC), Functional Assessment of Cancer Therapy-Social Support Subscale (FACT-ES), and Quality of Patient Information Questionnaire (QPI). Adherence to Tamoxifen (Tam) or Aromatase Inhibitors (AI) was examined using self-reported adherence and data from the Norwegian Prescription Database (NorPD) [corrected]. Kaplan-Meier curves and Cox proportional hazards regression models estimated adherence to ET.

RESULTS

The estimate of discontinued ET within 60 months was 38%. Self-reported discontinuation was 7% compared with 25% from the NorPD. Being overweight or obese were significantly time dependent factors predictive for discontinuing ET, p = 0.025.

CONCLUSION

Closer follow-ups, tailor-made information about the proven benefits of ET, and keeping a normal body mass index (BMI) may improve adherence to ET in postmenopausal women with breast cancer.

Clinical implications of low skeletal muscle mass in early-stage breast and colorectal cancer

Although obesity has now been widely accepted to be an important risk factor for cancer survival, the associations between BMI and cancer mortality have not been consistently linear. Although morbid obesity has clearly been associated with worse survival, some studies have suggested a U-shaped association with no adverse association with overweight or lower levels of obesity. This 'obesity paradox' may be due to the fact that BMI likely incompletely captures key measures of body composition, including distribution of skeletal muscle and adipose tissue. Fat and lean body mass can be measured using clinically acquired computed tomography scans. Many of the earlier studies focused on patients with metastatic cancer. However, skeletal muscle loss in the metastatic setting may reflect end-stage disease processes. Therefore, this article focuses on the clinical implication of low skeletal muscle mass in early-stage non-metastatic breast and colorectal cancer where measures of body composition have been shown to be strong predictors of disease-free survival and overall survival and also chemotherapy toxicity and operative risk.

Factors associated with physical inactivity in adult breast cancer survivors-A population-based study

Background

Physical activity has been shown to reduce the risk of breast cancer‐specific mortality. Although factors associated with physical inactivity in breast cancer survivors have been studied, a detailed examination at the population level is still lacking.

Methods

We addressed this gap in 1236 women with a diagnosis of breast cancer from the 2016 Behavioral Risk Factor Surveillance System Cancer Survivorship module. Physical inactivity was defined as self‐reported absence of leisure time physical activity. Factors examined in the multivariable logistic regression model included sociodemographic, behavioral factors, access to health care, health history, current cancer treatment, and pain from cancer or treatment.

Results

Overall, older age (≥65 years: OR = 2.63, 95% CI: 1.25‐5.55) and being underweight (BMI <18.5: OR = 6.11, 95% CI: 1.35‐27.66), were identified as significant factors associated with physical inactivity. In models adjusting for sociodemographics (Model 1), and the prior plus behavioral factors (Model 2), pain from cancer or treatment was significantly associated with physical inactivity (Model 2: OR = 2.23, 95% CI: 1.16‐4.28); however, after fully adjusting for all variables (Model 3), there was no longer evidence of a significant association between pain from cancer and physical activity in female survivors with breast cancer.

Conclusions

We identified demographic (older age) and physical (low BMI and pain) factors to be significantly associated with physical inactivity among breast cancer survivors. Future interventions to promote physical activity in breast cancer survivors could benefit by taking into account these factors to develop tailored recommendations for increasing activity.

Obesity and mortality after locoregional breast cancer diagnosis

PURPOSE

Higher mortality after a breast cancer diagnosis has been observed among women who are obese. We investigated the relationships between body mass index (BMI) and all-cause or breast cancer-specific mortality after a diagnosis of locoregional breast cancer.

METHODS

Women diagnosed in 2004 with AJCC Stage I, II, or III breast cancer (n = 5394) were identified from a population-based National Program of Cancer Registries (NPCR) patterns of care study (POC-BP) drawing from registries in seven U.S. states. Differences in overall and breast cancer-specific mortality were investigated using Cox proportional hazards regression models adjusting for demographic and clinical covariates, including age- and stage-based subgroup analyses.

RESULTS

In women 70 or older, higher BMI was associated with lower overall mortality (HR for a 5 kg/m² difference in BMI = 0.85, 95% CI 0.75-0.95). There was no significant association between BMI and overall mortality for women under 70. BMI was not associated with breast cancer death in the full sample, but among women with Stage I disease; those in the highest BMI category had significantly higher breast cancer mortality (HR for BMI ≥ 35 kg/m² vs. 18.5-24.9 kg/m² = 4.74, 95% CI 1.78-12.59).

CONCLUSIONS

Contrary to our hypothesis, greater BMI was not associated with higher overall mortality. Among older women, BMI was inversely related to overall mortality, with a null association among younger women. Higher BMI was associated with breast cancer mortality among women with Stage I disease, but not among women with more advanced disease.

Optimal body mass index cut-point for predicting recurrence-free survival in patients with non-muscle-invasive urothelial carcinoma of bladder

In Japanese patients with non-muscle-invasive urothelial carcinoma of the bladder, the impact of body mass index (BMI) on recurrence following transurethral resection of bladder tumor (TURBT) is unclear. The present study retrospectively examined data collected from 50 patients diagnosed with primary urothelial carcinoma of the bladder (pTa, pTis, and pT1) who had previously undergone TURBT surgery. Two BMI cut-off points for predicting disease recurrence were evaluated: i) A threshold generated through receiver operating characteristic (ROC) curve analysis; ii) the World Health Organization BMI index (24 kg/m²) for overweight status in Japanese populations. Univariate and multivariate analyses were applied to assess individual variables (BMI included) and the effect they had on recurrence-free survival (RFS). Median RFS and BMI values of 19.72 months (range, 3.13-72.13 months) and 23.37 kg/m2 (range, 14.72-36.84 kg/m2), respectively, were recorded. In multivariate analyses, higher continuous BMI was significantly associated with shorter RFS (P=0.019). Based on a ROC-generated BMI cut-off point (23.4 kg/m2), patients were ranked with either a high (≥23.4 kg/m2) or low (<23.4 kg/m2) BMI status. Multivariate analysis indicated that BMI values >23.4 kg/m2 were significantly associated with shorter RFS (P=0.028). Intravesical Bacillus Calmette-Guérin treatment and history of upper-tract urothelial carcinoma were also independently associated (P=0.044 and P=0.010, respectively). However, BMI values >24 kg/m2 (customary cut-off point) had no significant impact on RFS (P=0.066). Thus, a higher BMI status was revealed to be independently predictive of shorter RFS in Japanese patients undergoing TURBT for urothelial carcinoma of the bladder. A greater number of samples are required in order to determine optimal BMI cut-off points in Japanese patients and to investigate whether weight reduction intervention may improve prognosis.

Body mass index and prognosis of breast cancer: An analysis by menstruation status when breast cancer diagnosis

OBJECTIVE

To examine whether obesity/overweight is a risk predictor for breast cancer recurrence and death by menopausal status in a retrospective study.

METHODS

We performed a retrospective analysis of 1017 breast cancer patients treated in our hospital from January 2004 to December 2012. Three groups were divided according to body mass index (BMI) when breast cancer diagnosis: normal weight, BMI < 25.0 kg/m; overweight, 25.0≤BMI < 30.0 kg/m; and obesity, BMI≥30.0 kg/m. The clinicopathological characteristics and clinical outcomes of patients within 5 years following breast cancer diagnosed were analyzed. Subgroup analyses of BMI on breast cancer prognosis were analyzed according to the menopausal status when breast cancer diagnosis. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Overweight and obesity groups were associated with larger size tumors, older age, increased proportion of postmenopausal patients and less patients choosing anthracycline and/or taxane regimen. The 5-year disease-free survival (DFS) and overall survival (OS) decreased in overweight and obese patients (P < .001), and both overweight and obesity were independent predictors for increased risks of breast cancer relapse and death (P < .001). When stratified by menopausal status, both overweight and obesity were associated with reduced 5-year DFS and OS in postmenopausal patients (P < .050), and multivariate analysis showed that the risk of relapse and breast cancer mortality in these 2 groups also increased (P < .050). Among premenopausal patients, the risks of relapse and death were significantly increased in obesity group rather than overweight group by multivariate analysis.

CONCLUSION

Overweight and obesity might be independently associated with poorer prognosis for breast cancer patients, and the effects of overweight on the breast cancer prognosis seem to be related to menopausal status.

Can Nutrition Lower the Risk of Recurrence in Breast Cancer?

BACKGROUND

The impact of diet on breast cancer prognosis is poorly understood. Therefore, we conducted a literature search summarizing the current evidence on the effect of diet on breast cancer recurrence and mortality.

METHODS

The PubMed database was searched for original studies, reviews, and meta-analyses published between 2010 and 2017. Studies related to diet, dietary patterns, special diets or specific dietary factors, and breast cancer recurrence or mortality were included.

RESULTS

Adherence to high diet quality indices (relative risk (RR) 0.74, 95% confidence interval (CI) 0.60-0.90) and a prudent/healthy dietary pattern (RR 0.76, 95% CI 0.60-0.95) may have a beneficial effect on breast cancer prognosis, whereas a Western/unhealthy diet is associated with poorer overall mortality (RR 1.44, 95% CI 1.17-1.77). For low-fat diets, the findings are inconsistent. A positive effect of the Mediterranean Diet was found for all-cause mortality, but no beneficial effect from other diets such as low-carbohydrate, ketogenic or vegetarian/vegan diets was observed. Alcohol consumption was associated with an increased risk for breast cancer recurrence. No general recommendation for soy exists, but occasional intake seems to be acceptable, whereas the use of other supplements is not justified.

CONCLUSION

Adherence to high-quality diets and a prudent/healthy dietary pattern seem to be beneficial for breast cancer prognosis. No clear evidence for a benefit from special diets, soy products, or other supplements was found.

Association of Cardiovascular Risk Factors With Cardiac Events and Survival Outcomes Among Patients With Breast Cancer Enrolled in SWOG Clinical Trials

Background Cardiovascular disease is the primary cause of death among patients with breast cancer. However, the association of cardiovascular-disease risk factors (CVD-RFs) with long-term survival and cardiac events is not well studied. Methods We examined SWOG (formerly the Southwest Oncology Group) breast cancer trials from 1999 to 2011. We identified baseline diabetes, hypertension, hypercholesterolemia, and coronary artery disease by linking trial records to Medicare claims. The primary outcome was overall survival. Patients with both baseline and follow-up claims were examined for cardiac events. Cox regression was used to assess the association between CVD-RFs and outcomes. Results We identified 1,460 participants older than 66 years of age from five trials; 842 were eligible for survival outcomes analysis. At baseline, median age was 70 years, and median follow-up was 6 years. Hypertension (73%) and hypercholesterolemia (57%) were the most prevalent conditions; 87% of patients had one or more CVD-RF. There was no association between any of the individual CVD-RFs and overall survival except for hypercholesterolemia, which was associated with improved overall survival (hazard ratio [HR], 0.73; 95% CI, 0.57 to 0.93; P = .01). With each additional CVD-RF, there was an increased risk of death (HR, 1.23; 95% CI, 1.08 to 1.40; P = .002), worse progression-free survival (HR, 1.12; 95% CI, 1.00 to 1.25; P = .05), and marginally worse cancer-free survival (HR, 1.15; 95% CI, 0.99 to 1.34; P = .07). The relationship between baseline CVD-RFs and cardiac events was analyzed in 736 patients. A strong linear association between the number of CVD-RFs and cardiac event was observed (HR per CVD-RF, 1.41; 95% CI, 1.17 to 1.69; P < .001). Conclusion Among participants in clinical trials, each additional baseline CVD-RF was associated with an increased risk of cardiac events and death. Efforts to improve control of modifiable CVD-RFs are needed, especially among those with multiple risk factors.

Being slightly overweight is associated with a better quality of life in breast cancer survivors

To examine the association between BMI and QOL in breast cancer survivors in China, we conducted a cross-sectional survey and recruited 10708 breast cancer survivors. Survivors self-reported QOL was measured using the EORTC QLQ-C30 and the QLQ-BR23. The impact of BMI on QOL was examined through standard least squares regression. Normal weight and overweight survivors were more likely to have a better QOL than underweight and obese survivors and the results were similar to survivors diagnosed as having chronic diseases. After adjustment for clinical and sociodemographic factors, the QOL increased with increasing BMI in breast cancer survivors ranged from underweight to overweight with no chronic diseases, especially in the scales of emotional function and fatigue. Obese breast cancer survivors reported a significantly worse QOL compared to normal weight and overweight breast cancer survivors. Within breast cancer survivors with one or more chronic diseases, it was more obvious that overweight ones had a significantly better QOL with clear evidence of a dose relationship across underweight to overweight in almost all scales. Unlike obese breast cancer survivors without chronic diseases, the ones with chronic disease(s) had a similar QOL compared to normal weight breast cancer survivors in all scales except in the domain of fatigue.

Obesity and breast cancer outcomes in chemotherapy patients in New Zealand - a population-based cohort study

BACKGROUND

Obesity has been reported as an adverse prognostic factor in breast cancer, but inconsistently, and under-treatment with chemotherapy may occur. We provide the first assessment of obesity and breast cancer outcomes in a population-based, multi-ethnic cohort of New Zealand patients treated with chemotherapy.

METHODS

All 3536 women diagnosed with invasive breast cancer in the Waikato region of New Zealand from 2000-2014 were registered and followed until last follow-up in specialist or primary care, death or Dec 2014; median follow-up 4.1 years. For the 1049 patients receiving chemotherapy, mortality from breast cancer, other causes, and all causes, and rates of loco-regional and of distant recurrence, were assessed by body mass index (BMI), recorded after diagnosis, adjusting for other clinico-pathological and demographic factors by Cox regression.

RESULTS

BMI was known for 98% (n=1049); 33% were overweight (BMI 25-29.9), 21% were obese (BMI 30-34.9), and 14% were very obese (BMI 35+). There were no significant associations between obesity and survival, after adjustment for demographic and clinical factors (hazard ratios, HR, for very obese compared to BMI 21-24, for breast cancer deaths 0.96 (0.56-1.67), and for all deaths 1.03 (0.63-1.67), respectively, and only small non-significant associations for loco-regional or metastatic recurrence rates (HR 1.17 and 1.33 respectively). Subgroup analyses by age, menopausal status, ethnicity, stage, post-surgical radiotherapy, mode of diagnosis, type of surgery, and receptor status, showed no associations. No associations were seen with BMI as a continuous variable. The results in all patients irrespective of treatment but with recorded BMI data (n=2296) showed similar results.

CONCLUSIONS

In this population, obesity assessed post-diagnosis had no effect on survival or recurrence, based on 1049 patients with chemotherapy treatment with follow-up up to 14 years.

Worse survival after breast cancer in women with anorexia nervosa

PURPOSE

A history of anorexia nervosa has been associated with a reduced risk of developing breast cancer. We investigated survival after breast cancer among women with a prior anorexia nervosa diagnosis compared with women in a population comparison group.

METHODS

This register-based study included combined data from Sweden, Denmark and Finland. A total of 76 and 1462 breast cancer cases identified among 22,654 women with anorexia nervosa and 224,619 women in a population comparison group, respectively, were included in the study. Hazard ratios (HR) for overall and breast cancer-specific mortality after breast cancer diagnosis were estimated using Cox regression. Cause of death was available only for Swedish and Danish women; therefore, the analysis on breast cancer-specific mortality was restricted to these women.

RESULTS

We observed 23 deaths after breast cancer among anorexia nervosa patients and 247 among population comparisons. The overall mortality after the breast cancer diagnosis was increased in women with a history of anorexia nervosa compared with population comparisons (HR 2.5, 95% CI 1.6-3.9) after adjustment for age, period and extent of disease. Results were similar for overall (HR 2.3, 95% CI 1.4-3.6) and breast cancer-specific mortality (HR 2.1, 95% CI 1.3-3.6) among Swedish and Danish women.

CONCLUSIONS

We found that female breast cancer patients with a prior diagnosis of anorexia nervosa have a worse survival compared with other breast cancer patients.

The impact of actual body weight-based chemotherapy dosing and body size on adverse events and outcome in older patients with breast cancer: Results from Cancer and Leukemia Group B (CALGB) trial 49907 (Alliance A151436)

OBJECTIVE

Actual weight-based (AWB) chemotherapy dosing is recommended for obese patients in the 2012 ASCO Clinical Practice Guideline. CALGB 49907, which utilized ABW-based adjuvant chemotherapy dosing, was a phase 3 trial in women age≥65years with early stage breast cancer, providing the opportunity to examine impact of such dosing on toxicities and outcome in older patients with breast cancer.

MATERIALS AND METHODS

Adverse event data were available for 615 of 633 enrolled patients. Objectives were to assess grade≥3 hematologic/non-hematologic toxicities by treatment arm, age, study entry BSA/BMI, and relapse-free (RFS) and overall survival (OS) by BSA/BMI.

RESULTS

The 615 patients were sub-grouped by BSA (quartiles) and standard BMI categories, with BMI underweight/normal weight categories combined. Overall, grade≥3 non-hematologic and hematologic toxicities occurred in 39.8% and 28.3% of patients, respectively. There were no significant differences in grade≥3 toxicities among BSA quartiles. However, more grade≥3 hematologic toxicities occurred in the underweight/normal weight BMI subgroup compared to overweight/obese subgroups (p=0.048). Type of chemotherapy and age had no impact on toxicity occurrence by BSA/BMI categories. RFS was superior in the 25th-50th BSA percentile patients in univariate analysis (p=0.042), as was OS in both univariate and multivariate analyses (p=0.007, p=0.009, respectively). No differences in RFS or OS were found by BMI categories.

CONCLUSION

Obesity was not correlated with adverse relapse or survival outcome, and grade≥3 toxicities were not greater with ABW-based dosing. This supports safety and efficacy of ABW-based dosing as per the 2012 ASCO clinical practice guideline. ClinicalTrials.gov Identifier: NCT00024102 (49907).

Obesity, physical activity, and breast cancer survival among older breast cancer survivors in the Cancer Prevention Study-II Nutrition Cohort

PURPOSE

Nearly half of the 3.5 million female breast cancer survivors in the US are aged 65 years or older at diagnosis, yet little is known about associations of obesity and physical activity with breast cancer-specific mortality (BCSM) among older survivors.

METHODS

Between 1992 and 2013, 5254 women in the Cancer Prevention Study-II Nutrition Cohort were diagnosed with local or regional breast cancer among whom 1771 deaths (505 breast cancer deaths) occurred. Multivariable Cox proportional hazards regression models were used to examine associations of pre- and post-diagnosis body mass index (BMI) and moderate-vigorous physical activity (MET-hours/week) with mortality outcomes stratified by age at diagnosis (<65, ≥65 years).

RESULTS

Among women ≥65 years of age at diagnosis (n = 4226), pre- and post-diagnosis BMI (per 5 kg/m²) were associated with a higher risk of BCSM (pre-diagnosis, HR 1.27, 95% CI 1.14-1.41; post-diagnosis, HR 1.19, 95% CI 1.04, 1.36); neither pre- nor post-diagnosis physical activity was associated with BCSM. Among women <65 years of age at diagnosis (n = 1028), BMI at both time points were not significantly associated with BCSM; however, there was a significant inverse trend of post-diagnosis physical activity with BCSM (P-trend = 0.01). Among both age groups, BMI and physical activity, regardless of when assessed, were significantly associated with all-cause mortality.

CONCLUSIONS

Higher BMI, pre- or post-diagnosis, was associated with a higher risk of BCSM in older patients, independent of comorbidities and stage at diagnosis. Weight management should be discussed even with women aged 65 years or older to lower rates of BCSM.

Body mass index, waist-to-hip ratio and late outcomes: a report from the Shanghai Breast Cancer Survival Study

Obesity has been well studied in relation to breast cancer survival. However, the associations of post-diagnosis obesity and late outcomes (≥5 years after diagnosis) have been much less studied. A total of 4062 5-year disease-free patients were recruited from the Shanghai Breast Cancer Survival Study, a longitudinal study of patients diagnosed during 2002-2006. Cox proportional hazard model with restricted cubic spline were used to evaluate the potential non-linear associations of post-diagnosis body mass index (BMI) and waist-to-hip ratio (WHR) with late all-cause mortality and late recurrence. While no significant association was observed for post-diagnosis BMI or WHR with late recurrence; a U-shaped association was observed for the two measures with late all-cause death. Women with BMI of 25.0 kg/m2 or WHR of 0.83 were at the lowest risk of late all-cause mortality, whereas those with BMI beyond the range of 22.1-28.7 kg/m2 or WHR beyond the range of 0.81-0.86 had a higher risk. ER, stage or menopausal status did not modify the effect of post-diagnosis BMI or WHR on the outcomes. In conclusion, post-diagnosis BMI and WHR, as indicators of overall and central obesity respectively, were associated with late all-cause mortality in U-shaped pattern among long-term breast cancer survivors.

Health-related behaviors and mortality outcomes in women diagnosed with ductal carcinoma in situ

PURPOSE

Women diagnosed with ductal carcinoma in situ (DCIS) of the breast are at greater risk of dying from cardiovascular disease and other causes than from breast cancer, yet associations between health-related behaviors and mortality outcomes after DCIS have not been well studied.

METHODS

We examined the association of body mass index, physical activity, alcohol consumption, and smoking with mortality among 1925 women with DCIS in the Wisconsin In Situ Cohort study. Behaviors were self-reported through baseline interviews and up to three follow-up questionnaires. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for mortality after DCIS, with adjustment for patient sociodemographic, comorbidity, and treatment factors.

RESULTS

Over a mean of 6.7 years of follow-up, 196 deaths occurred. All-cause mortality was elevated among women who were current smokers 1 year prior to diagnosis (HR = 2.17 [95% CI 1.48, 3.18] vs. never smokers) and reduced among women with greater physical activity levels prior to diagnosis (HR = 0.55 [95% CI: 0.35, 0.87] for ≥5 h per week vs. no activity). Moderate levels of post-diagnosis physical activity were associated with reduced all-cause mortality (HR = 0.31 [95% CI 0.14, 0.68] for 2-5 h per week vs. no activity). Cancer-specific mortality was elevated among smokers and cardiovascular disease mortality decreased with increasing physical activity levels.

CONCLUSIONS

There are numerous associations between health-related behaviors and mortality outcomes after a DCIS diagnosis.

IMPLICATIONS FOR CANCER SURVIVORS

Women diagnosed with DCIS should be aware that their health-related behaviors are associated with mortality outcomes.

Body mass index, PAM50 subtype, recurrence, and survival among patients with nonmetastatic breast cancer

BACKGROUND

Studies of obesity and survival among patients with breast cancer produce conflicting results, possibly because of heterogeneity by molecular subtype.

METHODS

This study examined whether the association of body mass index (BMI) at diagnosis with breast cancer recurrence and survival varied across subtypes defined by PAM50 (Prediction Analysis of Microarray 50) gene expression. Included were 1559 Kaiser Permanente Northern California members ages 18 to 79 years who had PAM50 assays and were diagnosed with American Joint Committee on Cancer stage I through III breast cancer from 1996 to 2013. Patients reported weight and height. Cox regression models were adjusted for age, menopause, race/ethnicity, stage, and chemotherapy.

RESULTS

Over a median of 9 years (maximum, 19 years), 378 women developed recurrent disease, and 312 died from breast cancer. Overall, BMI was not associated with breast cancer recurrence or survival when controlling for subtype (eg, the hazard ratio per 5 kg/m² of BMI was 1.05 [95% confidence interval, 0.95-1.15] for breast cancer-specific death). However, associations varied by subtype. Among women with luminal A cancers, those who had class II/III obesity, but not class I obesity or overweight, had worse outcomes. When women who had a BMI ≥35 kg/m² were compared with those who had a BMI from 18.5 to <25 kg/m² , the hazard ratio was 2.24 (95% confidence interval,1.22-4.11) for breast cancer-specific death and 1.24 (95% confidence interval, 1.00-1.54) for recurrence. There was no association within luminal B, basal-like or human epidermal growth factor over-expressing subtypes.

CONCLUSIONS

Among patients who had accurately classified breast cancer subtypes based on gene expression, a BMI ≥35 kg/m² was adversely associated with outcomes only among those who had luminal A cancers. Research is needed into whether tailoring recommendations for weight management to tumor characteristics will improve outcomes. Cancer 2017;123:2535-42. © 2017 American Cancer Society.

Interaction between body mass index and hormone-receptor status as a prognostic factor in lymph-node-positive breast cancer

The aim of this study was to determine the relationship between the body mass index (BMI) at a breast cancer diagnosis and various factors including the hormone-receptor, menopause, and lymph-node status, and identify if there is a specific patient subgroup for which the BMI has an effect on the breast cancer prognosis. We retrospectively analyzed the data of 8,742 patients with non-metastatic invasive breast cancer from the research database of Asan Medical Center. The overall survival (OS) and breast-cancer-specific survival (BCSS) outcomes were compared among BMI groups using the Kaplan-Meier method and Cox proportional-hazards regression models with an interaction term. There was a significant interaction between BMI and hormone-receptor status for the OS (P = 0.029), and BCSS (P = 0.013) in lymph-node-positive breast cancers. Obesity in hormone-receptor-positive breast cancer showed a poorer OS (adjusted hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 0.92 to 2.48) and significantly poorer BCSS (HR = 1.80, 95% CI = 1.08 to 2.99). In contrast, a high BMI in hormone-receptor-negative breast cancer revealed a better OS (HR = 0.44, 95% CI = 0.16 to 1.19) and BCSS (HR = 0.53, 95% CI = 0.19 to 1.44). Being underweight (BMI < 18.50 kg/m²) with hormone-receptor-negative breast cancer was associated with a significantly worse OS (HR = 1.98, 95% CI = 1.00–3.95) and BCSS (HR = 2.24, 95% CI = 1.12–4.47). There was no significant interaction found between the BMI and hormone-receptor status in the lymph-node-negative setting, and BMI did not interact with the menopause status in any subgroup. In conclusion, BMI interacts with the hormone-receptor status in a lymph-node-positive setting, thereby playing a role in the prognosis of breast cancer.

Impact of Social and Built Environment Factors on Body Size among Breast Cancer Survivors: The Pathways Study

Background: As social and built environment factors have been shown to be associated with physical activity, dietary patterns, and obesity in the general population, they likely also influence these health behaviors among cancer survivors and thereby impact survivorship outcomes.Methods: Enhancing the rich, individual-level survey and medical record data from 4,505 breast cancer survivors in the Pathways Study, a prospective cohort drawn from Kaiser Permanente Northern California, we geocoded baseline residential addresses and appended social and built environment data. With multinomial logistic models, we examined associations between neighborhood characteristics and body mass index and whether neighborhood factors explained racial/ethnic/nativity disparities in overweight/obesity.Results: Low neighborhood socioeconomic status, high minority composition, high traffic density, high prevalence of commuting by car, and a higher number of fast food restaurants were independently associated with higher odds of overweight or obesity. The higher odds of overweight among African Americans, U.S.-born Asian Americans/Pacific Islanders, and foreign-born Hispanics and the higher odds of obesity among African Americans and U.S.-born Hispanics, compared with non-Hispanic whites, remained significant, although somewhat attenuated, when accounting for social and built environment features.Conclusions: Addressing aspects of neighborhood environments may help breast cancer survivors maintain a healthy body weight.Impact: Further research in this area, such as incorporating data on individuals' perceptions and use of their neighborhood environments, is needed to ultimately inform multilevel interventions that would ameliorate such disparities and improve outcomes for breast cancer survivors, regardless of their social status (e.g., race/ethnicity, socioeconomic status, nativity). Cancer Epidemiol Biomarkers Prev; 26(4); 505-15. ©2017 AACRSee all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences."

Association between Body Mass Index and Cancer Survival in a Pooled Analysis of 22 Clinical Trials

BACKGROUND

Data are inconsistent on the association between body mass index (BMI) at time of cancer diagnosis and prognosis. We used data from 22 clinical treatment trials to examine the association between BMI and survival across multiple cancer types and stages.

METHODS

Trials with ≥5 years of follow-up were selected. Patients with BMI < 18.5 kg/m2 were excluded. Within a disease, analyses were limited to patients on similar treatment regimens. Variable cutpoint analysis identified a BMI cutpoint that maximized differences in survival. Multivariable Cox regression analyses compared survival between patients with BMI above versus below the cutpoint, adjusting for age, race, sex, and important disease-specific clinical prognostic factors.

RESULTS

A total of 11,724 patients from 22 trials were identified. Fourteen analyses were performed by disease site and treatment regimen. A cutpoint of BMI = 25 kg/m2 maximized survival differences. No statistically significant trend across all 14 analyses was observed (mean HR = 0.96; P = 0.06). In no cancer/treatment combination was elevated BMI associated with an increased risk of death; for some cancers there was a survival advantage for higher BMI. In sex-stratified analyses, BMI ≥ 25 kg/m2 was associated with better overall survival among men (HR = 0.82; P = 0.003), but not women (HR = 1.04; P = 0.86). The association persisted when sex-specific cancers were excluded, when treatment regimens were restricted to dose based on body surface area, and when early-stage cancers were excluded.

CONCLUSION

The association between BMI and survival is not consistent across cancer types and stages.

IMPACT

Our findings suggest that disease, stage, and gender-specific body size recommendations for cancer survivors may be warranted. Cancer Epidemiol Biomarkers Prev; 26(1); 21-29. ©2016 AACR SEE ALL THE ARTICLES IN THIS CEBP FOCUS SECTION, "THE OBESITY PARADOX IN CANCER EVIDENCE AND NEW DIRECTIONS".

How to Manage the Obese Patient With Cancer

Purpose

Obesity (body mass index [BMI] ≥ 30 kg/m2) is common among patients with cancer. We reviewed management issues in the obese patient with cancer, focusing on how obesity influences treatment selection (including chemotherapy dosing), affects chemotherapy toxicity and surgical complications, and might be a treatment effect modifier.

Methods

The majority of evidence is drawn from observational studies and secondary analyses of trial data, typically analyzed in N × 3 BMI categories (normal weight, overweight, and obese) matrix structures. We propose a methodological framework for interpretation focusing on sample size and composition, nonlinearity, and unmeasured confounding.

Results

There is a common perception that obesity is associated with increased treatment-related toxicity. Accordingly, cytotoxic chemotherapy dose reduction is common in patients with elevated BMI. Contrary to this, there is some evidence that full dosing in obese patients does not result in increased toxicity. However, these data are from a limited number of regimens, and fail to fully capture cytotoxic drug pharmacodynamics and pharmacokinetic variability in obese patients. Among patients undergoing surgery, there is evidence that elevated BMI is associated with increased perioperative mortality and increased rates of infectious complications. A novel finding is that these relationships hold after surgery for malignancy, but not for benign indications. There are biologic plausibilities that obesity might be an effect modifier of treatment, but supporting evidence from clinical studies is inconsistent.

Conclusion

In line with the ASCO 2012 guidelines, chemotherapy dosing is probably best performed using actual body weight in obese patients. However, specific regimens known to be associated with increased toxicity in this group should be used with caution. There is no guidance on dose for obese patients treated with biologic agents. Currently, there are no specific recommendations for the surgical management of the obese patient with cancer.