The influence of body mass index on survival in breast cancer patients

Gut Microbiome and Symptom Burden in Obese and Non-Obese Women Receiving Chemotherapy for Breast Cancer

Purpose: Obese women with breast cancer experience high symptom burden, poor quality of life, and increased mortality compared to non-obese women with breast cancer. Obesity-related changes to the bacteria of the gut, the GI microbiome, may be one such mechanism for these differences in outcomes. The purpose of this work is to report symptom burden and GI microbiome composition between obese and non-obese women with breast cancer to identify potential microbial influences for symptom severity. Methods: 59 women with breast cancer (26 obese, 33 non-obese) provided symptom reports using the Memorial Symptom Assessment Scale and stool samples for 16S analysis one week after receiving chemotherapy. Symptom reports were summarized and examined for differences based on obesity. Fecal microbiome analysis was compared between groups using alpha-diversity (Shannon index), beta-diversity (Principal Coordinate Analysis with weighted UniFrac distances), and LASSO analysis of abundance of bacterial species. Results: While symptom burden was high, it did not differ based on obesity status. Alpha- and beta-diversity did not find significant differences based on obesity, but LASSO analysis identified eight bacteria to be significantly enriched in obese participants: Collinsella aerofacien, Prevotella 7, Coprobacillus cateniformis, Ruminococcus torques group, Agathobacter, Frisingicoccus, Roseburia inulinivorans, and Monoglobus pectinilyticus. Conclusions: Identifying biologic mechanisms driving symptoms is necessary for the development of therapies to reduce cancer-related symptom burden. While obesity may alter the GI microbiome and influence symptom burden in women with breast cancer, these effects may be outweighed by the effects of chemotherapy on the gut.

Excess Body Weight and Cancer-Related Fatigue, Systemic Inflammation, and Serum Lipids in Breast Cancer Survivors

BACKGROUND

Cancer-related fatigue (CRF) is a common side effect impacting breast cancer survivors. Research points to a relationship between obesity and CRF in breast cancer survivors related to elevated systemic inflammation and metabolic alterations.

METHODS

This cross-sectional study examined the relationship of obesity to CRF, inflammatory markers and serum lipids through a secondary analysis of a nationwide randomized controlled trial. Breast cancer survivors with CRF were categorized based on BMI category. Symptoms of CRF, inflammatory markers and serum fatty acids were assessed among groups.

RESULTS

There were 105 breast cancer survivors in the analysis. BMI was positively associated with CRF based on MFSI General (p = 0.020; 95% C.I. 0.024, 0.273) and MFSI Physical (p = 0.013; 95% C.I. 0.035, 0.298) subscales. TNF-α (p = 0.007; 95% C.I. 0.007, 0.044), and IL-6 (p = 0.020; 95% C.I. 0.006, 0.073) were elevated in the obese. Monounsaturated fatty acid levels (p = 0.047; 95% C.I. 0.000, 0.053) and the omega-6 to omega-3 fatty acid ratio were associated with obesity (p = 0.047; 95% C.I. 0.002, 0.322).

CONCLUSIONS

Obese breast cancer survivors had greater levels of CRF, inflammatory markers and certain fatty acids. Inflammatory markers and fatty acids were not found to have any mediating or positive association with CRF variables in this analysis. NCT02352779.

Cancer-related Fatigue in Breast Cancer Survivors: A Review

Fatigue has been the most distressing and frequent symptom in breast cancer (BC) survivors after treatment. Although fatigue can occur in other cancer survivors, women with a history of BC might share some distinctive features. The present study aimed to recapitulate the knowledge about risk factors and correlates of cancer-related fatigue (CRF) in BC survivors after oncologic therapy. An electronic data search was conducted in PubMed using the terms "fatigue," "breast," "cancer," and "survivors." Records were included if they were original articles, available in English, had used a quantitative scale, had > 100 participants, and had excluded women with BC relapse. BC survivors were required to have finished their treatments ≥ 2 months before, except for hormonal therapy. The physiopathology and other interventions were considered beyond the scope of our review. The correlates were subsequently classified into 7 main categories: (1) sociodemographic data, (2) physical variables, (3) tumor- and treatment-related variables, (4) comorbidities, (5) other symptoms, (6) psychological issues, and (7) lifestyle factors. Fatigue was consistently greater in younger, obese, and diabetic women. Women reporting fatigue often communicated symptoms such as pain, depression, insomnia, and cognitive dysfunction. Coping strategies such as catastrophizing could play an important role in the persistence of fatigue. However, tumor characteristics, previous treatments received, and physical activity were not consistently reported. CRF was a strong predictor of the quality of life of BC survivors after treatment. In conclusion, we found CRF was a frequent and serious symptom that severely affects the quality of life of BC survivors after treatment. Health practitioners require more awareness and information about CRF.

A Web-Based Exercise System (e-CuidateChemo) to Counter the Side Effects of Chemotherapy in Patients With Breast Cancer: Randomized Controlled Trial

Background

Breast cancer patients have to face a high-risk state during chemotherapy, which involves deterioration of their health including extensive physical deterioration. Face-to-face physical exercise programs have presented low adherence rates during medical treatment, and telehealth systems could improve these adherence rates.

Objective

This study aimed to evaluate the effectiveness of a Web-based exercise program (e-CuidateChemo) to mitigate the side effects of chemotherapy on the physical being, anthropometric aspects, and body composition.

Methods

A total of 68 patients diagnosed with breast cancer, who were undergoing chemotherapy, were enrolled. The patients were categorized into two groups: e-CuidateChemo (n=34) and controls (n=34). The e-CuidateChemo group participated in an adapted 8-week tailored exercise program through a Web-based system. A blinded, trained researcher assessed functional capacity, strength, anthropometric parameters, and body composition. The intervention effects were tested using analysis of covariance and Cohen d tests.

Results

Functional capacity improved significantly in the e-CuidateChemo group compared to the control group (6-minute walk test: 62.07 [SD 130.09] m versus –26.34 [SD 82.21] m; 6-minute walk test % distance predicted: 10.81% [SD 22.69%] m versus –4.60% [SD 14.58%]; between-group effect: P=.015 for both). The intervention group also showed significantly improved secondary outcomes such as between-group effects for abdominal (24.93 [SD 26.83] s vs –18.59 [SD 38.69] s), back (12.45 [SD 10.20] kg vs 1.39 [10.72] kg), and lower body (–2.82 [SD 3.75] s vs 1.26 [SD 2.84] s) strength; all P<.001 compared to the control group.

Conclusions

This paper showed that a Web-based exercise program was effective in reversing the detriment in functional capacity and strength due to chemotherapy.

Trial Registration

ClinicalTrials.gov NCT02350582; https://clinicaltrials.gov/ct2/show/NCT02350582

Longitudinal assessment of the impact of higher body mass index on cancer-related fatigue in patients with breast cancer receiving chemotherapy

PURPOSE

To assess the impact of obesity on cancer-related fatigue (CRF) in patients with breast cancer, through a secondary analysis of a large, longitudinal, nationwide study of breast cancer patients beginning chemotherapy.

METHODS

All patients (N = 565; aged 53 ± 10.6) with breast cancer completed the multidimensional fatigue symptom inventory and the symptom inventory to measure CRF symptoms at baseline, post-chemotherapy, and 6 months post-chemotherapy. Height and weight at baseline were used to categorize subjects based on body mass index (BMI): obese (≥ 30.0 kg/m²; n = 294), overweight (25.0-29.9 kg/m²; n = 146), and normal weight (18.5-24.9 kg/m²; n = 125). Multivariate regression models evaluated the relationship of obesity level to CRF over time, controlling for age, menopausal status, race, Karnofsky Performance Status, cancer stage, radiation, and exercise status.

RESULTS

At baseline, the obese had significantly higher CRF symptoms than the normal weight subjects for both the Multidimensional fatigue symptom inventory (MFSI) total (obese = 11.2 vs normal weight = 6.3; p = 0.03) and Symptom Inventory (SI) (obese = 3.5 vs normal weight = 2.9; p = 0.03). Significantly higher SI fatigue scores persisted at post-chemotherapy for the obese (obese = 5.0 vs normal weight = 4.4; p = 0.02). At 6 months post-chemotherapy, the obese patients still had significantly higher SI fatigue scores (obese = 3.5 vs normal weight = 3.0; p = 0.05).

CONCLUSION

Obese patients suffered greater CRF from pre-chemotherapy through 6 months post-chemotherapy. Recommendations for weight loss or weight maintenance may impact CRF levels in obese breast cancer patients before and after chemotherapy.

Obesity-Linked Cancers: Current Knowledge, Challenges and Limitations in Mechanistic Studies and Rodent Models

The worldwide prevalence of obesity has doubled during the last 50 years, and according to the World Obesity Federation, one third of the people on Earth will be obese by the year 2025. Obesity is described as a chronic, relapsing and multifactorial disease that causes metabolic, biomechanical, and psychosocial health consequences. Growing evidence suggests that obesity is a risk factor for multiple cancer types and rivals smoking as the leading preventable cause for cancer incidence and mortality. The epidemic of obesity will likely generate a new wave of obesity-related cancers with high aggressiveness and shortened latency. Observational studies have shown that from cancer risk to disease prognosis, an individual with obesity is consistently ranked worse compared to their lean counterpart. Mechanistic studies identified similar sets of abnormalities under obesity that may lead to cancer development, including ectopic fat storage, altered adipokine profiles, hormone fluctuations and meta-inflammation, but could not explain how these common mechanisms produce over 13 different cancer types. A major hurdle in the mechanistic underpinning of obesity-related cancer is the lack of suitable pre-clinical models that spontaneously develop obesity-linked cancers like humans. Current approaches and animal models fall short when discerning the confounders that often coexist in obesity. In this mini-review, we will briefly survey advances in the different obesity-linked cancers and discuss the challenges and limitations in the rodent models employed to study their relationship. We will also provide our perspectives on the future of obesity-linked cancer research.

Relationship between body mass index and outcomes for patients with oral squamous cell carcinoma

OBJECTIVE

The purpose of our study was to investigate body mass index (BMI) as a prognostic factor and to examine the relationship between pretreatment BMI and oral squamous cell carcinoma (OSCC) outcomes in northern Chinese patients.

METHODS

This retrospective study enrolled 633 patients with OSCC who underwent surgery between 2004 and 2014.

RESULTS

Most baseline characteristics (gender, sites, smoking history, comorbidity, hypertension, T stage, clinical features, perineural invasion, flap reconstruction) were differentiated by BMI groups. Overall, the Kaplan-Meier curves indicated no significant relationship between BMI and disease-free survival (DFS) or disease-specific survival (DSS). Interestingly, obese patients exhibited higher risks of recurrence and death than normal-weight patients (DFS: HR: 1.86, 95% CI: 1.16-2.96; DSS: HR: 2.04, 95% CI: 1.08-3.86). However, postoperative complications occurred more frequently in underweight patients than in normal-weight patients.

CONCLUSIONS

Obesity may contribute to a higher recurrence rate and a worse prognosis in OSCC patients than in normal-weight patients in northern China. However, underweight patients have a higher risk of postoperative complications.

Evaluation of the effects of a clinically implemented exercise program on physical fitness, fatigue, and depression in cancer survivors

PURPOSE

Despite national recommendations, exercise programs are still not clinically implemented as standard of care for cancer survivors. This investigation examined the effects of a clinically implemented and personalized exercise program on physical fitness, fatigue, and depression in a diverse population of cancer survivors. The association of various participant characteristics on program performance was also examined.

METHODS

Data were collected from 170 cancer survivors who had participated in a clinical exercise program. Any cancer type was included and survivors were either undergoing medical treatment or had completed treatment (< 6 months prior to program initiation). Baseline and post program measures of estimated VO₂peak, grip strength, fatigue, and depression were compared in survivors who completed the program follow-up. Multiple regressions were performed to investigate the association of age, gender, body mass index (BMI), and medical treatment status on baseline and change scores in outcome measures, as well as program adherence.

RESULTS

All measures improved in participants who completed the program (p < 0.01). Age, gender, and BMI were associated with baseline measures of estimated VO₂peak and grip strength (p < 0.01), and age was inversely associated with baseline fatigue (p = 0.02). Only BMI was inversely associated with change in estimated VO₂peak (p < 0.01). No participant characteristics or baseline measures were predictive of program adherence (p > 0.05).

CONCLUSION

This investigation provides evidence that a personalized, clinical exercise program can be effective at improving physical fitness, fatigue, and depression in a diverse population of cancer survivors.