Lifestyle interventions for cardiovascular risk reduction in women with breast cancer

Tackling the adverse health effects of excess body fat in breast cancer: where does physical activity fit in?

Weight gain is commonly observed during and after breast cancer treatment due to chemotherapy and endocrine therapies, induced menopause, changes in metabolism and food intake and decreased physical activity. Systematic reviews show that women who are overweight or obese at diagnosis, and those who gain weight, have poorer breast cancer survival outcomes than women of a healthy weight, irrespective of menopausal status. Excess body weight after breast cancer also increases the risk of type 2 diabetes mellitus and CVD. The adverse impact of excess body weight on survival outcomes is clearly shown for women with oestrogen receptor-positive (ER+) breast cancer, which accounts for 70 % of all breast cancer cases. Higher body fat is thought to increase the risk of ER+ recurrence because of increased aromatase activity. However, this could be compounded by other risk factors, including abnormal insulin and adipokine metabolism, impaired anti-tumour immunity and chronic low-grade systemic inflammation. Observational evidence linking poorer survival outcomes with excess body fat and low physical activity in women recovering from early-stage curative-intent breast cancer treatment is reviewed, before reflecting on the proposed biological mechanisms. The issues and sensitivities surrounding exercise participation amongst overweight breast cancer patients is also discussed, before providing an overview of the co-design process involved in development of an intervention (support programme) with appropriate content, structure and delivery model to address the weight management challenges faced by overweight ER+ breast cancer patients.

Identifying key barriers to effective breast cancer control in rural settings

Breast cancer is the most common cancer and the second most common cause of cancer mortality among women in the United States. Efforts to promote breast cancer control in rural settings face specific challenges. Access to breast cancer screening, diagnosis, and treatment services is impaired by shortages of primary care and specialist providers, and geographic distance from medical facilities. Women in rural areas have comparable breast cancer mortality rates compared to women in urban settings, but this is due in large part to lower incidence rates and masks a substantial rural/urban disparity in breast cancer survival among women diagnosed with breast cancer. Mammography screening utilization rates are slightly lower among rural women than their urban counterparts, with a corresponding increase in late stage breast cancer. Differences in breast cancer survival persist after controlling for stage at diagnosis, largely due to disparities in access to treatment. Travel distance to treatment centers is the most substantial barrier to improved breast cancer outcomes in rural areas. While numerous interventions have been demonstrated in controlled studies to be effective in promoting treatment access and adherence, widespread dissemination in public health and clinical practice remains lacking. Efforts to improve breast cancer control in rural areas should focus on implementation strategies for improving access to breast cancer treatments.

Cardiorespiratory fitness and adiposity in breast cancer survivors: is meeting current physical activity recommendations really enough?

PURPOSE

Breast cancer (BC) survivors are becoming increasingly predisposed to cardiovascular disease (CVD) mortality. Low cardiorespiratory fitness and physical activity (PA) levels, as well as high values of adiposity indices, contribute to CVD risk. We evaluated adiposity, cardiorespiratory profile, and PA levels in two independent cohorts of BC survivors.

METHODS

Data were collected from two groups (99% women) from different areas of Madrid (Spain): group 1, n = 110, age 51.4 ± 9.7 years, median time from diagnosis 365 days (95% confidence interval [CI], 354-401), and group 2, n = 93, age 54.7 ± 8.9 years, 1714 days (95% CI, 1502-1938). We estimated peak oxygen uptake (VO2peak) and measured body mass index (BMI), waist circumference (WC), waist-to-hip index, and accelerometry-determined PA.

RESULTS

Both groups had values of BMI in the overweight range (25.3 ± 4.3 and 27.1 ± 5.1 kg/m2, p = 0.003). Estimated VO2peak levels were lower in group 2 than in group 1 (28.1 ± 9.1 and 23.7 ± 8.8 ml/kg/min, p < 0.001), although levels in both groups were low. Yet, the majority of participants in both groups (81 and 88%, p = 0.234) met international PA recommendations (235 ± 196 and 351 ± 173 min/week of moderate-vigorous PA, p < 0.001). Both groups had very low levels of vigorous PA. These results were essentially independent of type of treatment (anthracycline/radiotherapy).

CONCLUSIONS

We found a poor cardiorespiratory profile in two independent BC cohorts that differed in median time from diagnosis (as well in socioeconomic status), supporting the notion that implementation of PA (possibly focusing on vigorous PA) and dietary intervention is urgently needed in this patient population.

Cardiovascular and Cancer Risk: The Role of Cardio-oncology

Cardio-oncology is a subspecialty of cardiology. It was created to address oncology data indicating that newly developed drugs for cancer treatment were having unanticipated cardiac side effects. Cardio-oncology designs primary and secondary risk strategies through surveillance as well as interventions to reduce cardiovascular risk (CVR), prevent cardiotoxicities, and manage the side effects that may occur. Rather than discuss in detail the cardiotoxicities of specific therapies or radiation, this review article will explore the interplay of cancer, cancer treatment, and CVR. It will examine the link between CVR and cancer risk, define mechanisms associated with cardiotoxicity, and describe screening and surveillance for patients undergoing cancer treatment. Finally, effective preventative and management strategies used to reduce the incidence of cardiotoxicities in those receiving chemotherapeutics or radiation will be presented.

Cardiovascular disease and mortality after breast cancer in postmenopausal women: Results from the Women's Health Initiative

Background

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality among older postmenopausal women. The impact of postmenopausal breast cancer on CVD for older women is uncertain. We hypothesized that older postmenopausal women with breast cancer would be at a higher risk of CVD than similar aged women without breast cancer and that CVD would be a major contributor to the subsequent morbidity and mortality.

Methods

In a prospective Women’s Health Initiative study, incident CVD events and total and cause-specific death rates were compared between postmenopausal women with (n = 4,340) and without (n = 97,576) incident invasive breast cancer over 10 years post-diagnosis, stratified by 3 age groups (50–59, 60–69, and 70–79).

Results

Postmenopausal women, regardless of breast cancer diagnosis, had similar and high levels of CVD risk factors (e.g., smoking and hypertension) at baseline prior to breast cancer, which were strong predictors of CVD and total mortality over time. CVD affected mostly women age 70–79 with localized breast cancer (79% of breast cancer cases in 70–79 age group): only 17% died from breast cancer and CVD was the leading cause of death (22%) over the average 10 years follow up. Compared to age-matched women without breast cancer, women age 70–79 at diagnosis of localized breast cancer had a similar multivariate-adjusted hazard ratio (HR) of 1.01 (95% confidence interval [CI]: 0.76–1.33) for coronary heart disease, a lower risk of composite CVD (HR = 0.84, 95% CI: 0.70–1.00), and a higher risk of total mortality (HR = 1.20, 95% CI: 1.04–1.39).

Conclusion

CVD was a major contributor to mortality in women with localized breast cancer at age 70–79. Further studies are needed to evaluate both screening and treatment of localized breast cancer tailored to the specific health issues of older women.

The Yale Fitness Intervention Trial in female cancer survivors: Cardiovascular and physiological outcomes

BACKGROUND

Induced premature menopause and cardio-toxic therapy increase cardiovascular disease risk in female cancer survivors.

OBJECTIVE

To compare the effects of a 12 month aerobic-resistance fitness center intervention to home based physical activity on cardiovascular function and metabolic risk factors.

METHODS

Subjects (N = 154) who had completed primary and/or adjuvant chemotherapy (past 3 years) were randomized to a fitness center intervention or a home based group. The fitness center intervention was a structured thrice weekly aerobic (30 min brisk walking treadmill in target heart range) combined with resistance (30 min of lower body strength training) exercise program, supervised for the first 6 months. The home based group received national guidelines for 30 min moderate intensity exercise most days of the week. Fasting serum samples were collected at baseline, 6 and 12 months for insulin, glucose, lipids and hemoglobin A-1C. A graded exercise stress test was also performed at baseline and 6 months.

RESULTS

The majority of subjects were white (85.7%), had breast cancer (83.1%) and the average age was 51.9 years. Subjects in the fitness center intervention had significantly improved time on treadmill (p = .039), improved heart rate recovery at 1 min (p = .028), greater MET minutes/week (p ≤ .0001), a trend for improved insulin resistance (p = .067) and stable insulin levels (p = .045) compared to the home based physical activity group.

CONCLUSIONS

Exercise represents a potential cardiac risk reduction intervention for cancer survivors. CLINICAL TRIALS.GOV: NCT01102985.

The effects of a home-based physical activity intervention on cardiorespiratory fitness in breast cancer survivors; a randomised controlled trial

The aim of this current randomised controlled trial was to evaluate the effects of a home-based physical activity (PA) intervention on cardiorespiratory fitness in breast cancer survivors. Thirty-two post-adjuvant therapy breast cancer survivors (age = 52 ± 10 years; BMI = 27.2 ± 4.4 kg∙m²) were randomised to a six-month home-based PA intervention with face-to-face and telephone PA counselling or usual care. Cardiorespiratory fitness and self-reported PA were assessed at baseline and at six-months. Participants had a mean relative V̇O₂max of 25.3 ± 4.7 ml∙kg^-1∙min^-1, which is categorised as "poor" according to age and gender matched normative values. Magnitude-based inference analyses revealed likely at least small beneficial effects (effect sizes ≥.20) on absolute and relative V̇O₂ max (d = .44 and .40, respectively), and total and moderate PA (d = .73 and .59, respectively) in the intervention compared to the usual care group. We found no likely beneficial improvements in any other outcome. Our home-based PA intervention led to likely beneficial, albeit modest, increases in cardiorespiratory fitness and self-reported PA in breast cancer survivors. This intervention has the potential for widespread implementation and adoption, which could considerably impact on post-treatment recovery in this population.

Cardiovascular disease and physical activity in adult cancer survivors: a nested, retrospective study from the Atlantic PATH cohort

PURPOSE

The study aimed to examine the relationship between cardiovascular disease (CVD) and physical activity (PA) levels in cancer survivors (CS).

METHODS

Using a nested, retrospective follow-up design, this study presents the self-reported prevalence of CVD in an Atlantic Canadian population-based cohort of 1526 CS and 6034 age-sex matched, non-cancer controls ranging from 35 to 69 years of age. Univariate and multiple logistic regression models were used to explore the association between CVD and PA.

RESULTS

Overall, CS were 30% more likely to have ever experienced a CVD event than controls (OR = 1.3; 95% CI 1-1.7, p = .07). Survivors were also significantly more likely to report having hypertension (OR = 1.60; 95% CI 1.03-1.3, p = .02) and diabetes (OR = 1.27; 95% CI 1.03-1.16, p = .02). Compared to controls, CS were significantly less likely to engage in high levels of PA. For survivors, compared to those who were least physically active, the odds of having a CVD risk factor was 35% lower for those who were moderately active (OR = 0.65; 95% CI 0.48-0.88) and 45% lower in the most highly active group (OR = 0.55; 95% CI 0.4-0.73). For controls, the odds of having a CVD risk factor was 25% lower for those in the moderately active group (OR = 0.75; 95% CI 0.64-0.88) and 30% lower for those in the high active group (OR = 0.70; 95% CI 0.6-0.81).

CONCLUSION

Low active survivors appear to be at a high risk of CVD-related comorbidity.

IMPLICATIONS FOR CANCER SURVIVORS

PA is associated with lower CVD-related comorbidity in CS, suggesting that interventions directed at increasing PA should be implemented to improve long-term health outcomes.

Integrative Therapies and Cardiovascular Disease in the Breast Cancer Population: A Review, Part 2

In Part 1 of the current review, the cardiotoxicity of standard breast cancer treatment was reviewed. Part 2 presents a comprehensive review of the current evidence for lifestyle factors, including nutrition and exercise. Part 2 describes the results of several dietary interventions in breast cancer survivors. Specific dietary factors that may promote cardiovascular health in this population, including essential fatty acids and plant phytosterols, are also reviewed. In addition, the mechanisms by which exercise may provide a benefit are discussed, and evidence for the important role of attainment and maintenance of a healthy weight is outlined. Finally, recommendations for lifestyle changes in the survivor population are discussed, and opportunities for future research in this population are identified.

The effect of a community-based exercise intervention on symptoms and quality of life

BACKGROUND

Moderate-intensity physical activity in women with breast cancer has been reported to improve physical and psychological outcomes. However, initiation and adherence to a routine physical activity program for cancer survivors after therapy may be challenging.

OBJECTIVE

The purpose of this study was to determine the feasibility and effect of a community-based exercise intervention on physical and psychological symptoms and quality of life in breast cancer survivors.

METHODS

A 1-group pretest-posttest design was used to evaluate a thrice weekly, 4- to 6-month supervised exercise intervention on symptoms and quality of life. Data were collected at baseline and end of the intervention, using the Breast Cancer Prevention Trial Checklist, the Symptom Distress Scale, the Centers for Epidemiology Scale for Depression, and the Medical Outcomes Short Form.

RESULTS

There were 26 participants, with a mean (SD) age of 51.3 (6.2) years; most were married, well educated, and employed. The intervention was delivered at 3 community fitness centers, and adherence ranged from 75% to 98%. Vasomotor, musculoskeletal, and cognitive symptoms were common, but only muscle stiffness, fatigue, and depression significantly changed over time (P = .04, .05, and .01, respectively). Quality of life improved significantly in the areas of physical, emotional, and social function; pain; vitality; and mental health.

CONCLUSIONS

Providing an exercise intervention in the community where women live and work is feasible and improves physical, psychological, and functional well-being.

IMPLICATIONS FOR PRACTICE

Exercise is a key component of cancer rehabilitation and needs to be integrated into our standard care.

Body mass index, physical activity, and mortality in women diagnosed with ovarian cancer: results from the Women's Health Initiative

BACKGROUND

Ovarian cancer is often diagnosed at late stages and consequently the 5-year survival rate is only 44%. However, there is limited knowledge of the association of modifiable lifestyle factors, such as physical activity and obesity on mortality among women diagnosed with ovarian cancer. The purpose of our study was to prospectively investigate the association of (1) measured body mass index (BMI), and (2) self-reported physical activity with ovarian cancer-specific and all-cause mortality in postmenopausal women enrolled in the Women's Health Initiative (WHI).

METHODS

Participants were 600 women diagnosed with primary ovarian cancer subsequent to enrollment in WHI. Exposure data, including measured height and weight and reported physical activity from recreation and walking, used in this analysis were ascertained at the baseline visit for the WHI. Cox proportional hazard regression was used to examine the associations between BMI, physical activity and mortality endpoints.

RESULTS

Vigorous-intensity physical activity was associated with a 26% lower risk of ovarian cancer specific-mortality (HR=0.74; 95% CI: 0.56-0.98) and a 24% lower risk of all-cause mortality (HR=0.76; 95% CI: 0.58-0.98) compared to no vigorous-intensity physical activity. BMI was not associated with mortality.

CONCLUSIONS

Participating in vigorous-intensity physical activity, assessed prior to ovarian cancer diagnosis, appears to be associated with a lower risk of ovarian cancer mortality.

Testing the 'teachable moment' premise: does physical activity increase in the early survivorship phase?

PURPOSE

Little is known about objectively measured physical activity during the early survivorship period. This study measured physical activity, fatigue, and quality of life (QOL) in breast cancer patients over the first year after completion of chemotherapy and compared results to a matched non-cancer group.

METHODS

Data was obtained from 24 breast cancer subjects (mean ± SD) 50.9 ± 12.8 years at time points of 6 weeks, 6 months and 1 year after completion of adjuvant chemotherapy and from 20 matched women. The following variables were assessed, physical activity (RT3 accelerometer and International Physical Activity Questionnaire), quality-of-life (EORTC QLQ C-30) and fatigue (Brief Fatigue Inventory).

RESULTS

At 6 weeks after completion of chemotherapy, high levels of sedentary behaviour were found (6.8 ± 1.9 h sedentary per day), which did not improve, and was no different to the comparison group (6.5 ± 1.4 h). Less light activity was performed in the cancer cohort compared to the comparison group (p = 0.003). Body mass index (BMI) increased significantly in the cancer cohort (p = 0.015) and 1 year after chemotherapy finished only 13% (n = 3) had a BMI <25, while the comparable value was 45% (n = 9) in the non-cancer group. The QOL domain of cognitive function improved over the first 6 months (p = 0.034) but physical functioning declined (p = 0.008) over this time period. Fatigue did not change, and at the 1-year time point, 38% of the cancer patients (n = 11) reported high levels of fatigue.

CONCLUSION

This study highlighted the unchanging sedentary behaviour and weight gain of breast cancer survivors during the first year after completion of chemotherapy, which may inform rehabilitation models in this population.