Physical activity and the risk of breast cancer in BRCA1/2 mutation carriers

Lifestyle Factors and Breast Cancer in Females with PTEN Hamartoma Tumor Syndrome (PHTS)

Females with PTEN Hamartoma Tumor Syndrome (PHTS) have breast cancer risks up to 76%. This study assessed associations between breast cancer and lifestyle in European female adult PHTS patients. Data were collected via patient questionnaires (July 2020-March 2023) and genetic diagnoses from medical files. Associations between lifestyle and breast cancer were calculated using logistic regression corrected for age. Index patients with breast cancer before PHTS diagnosis (breast cancer index) were excluded for ascertainment bias correction. In total, 125 patients were included who completed the questionnaire at a mean age of 44 years (SD = 13). This included 21 breast cancer indexes (17%) and 39 females who developed breast cancer at 43 years (SD = 9). Breast cancer patients performed about 1.1 times less often 0-1 times/week physical activity than ≥2 times (ORtotal-adj = 0.9 (95%CI 0.3-2.6); consumed daily about 1.2-1.8 times more often ≥1 than 0-1 glasses of alcohol (ORtotal-adj = 1.2 (95%CI 0.4-4.0); ORnon-breastcancer-index-adj = 1.8 (95%CI 0.4-6.9); were about 1.04-1.3 times more often smokers than non-smokers (ORtotal-adj = 1.04 (95%CI 0.4-2.8); ORnon-breastcancer-index-adj = 1.3 (95%CI 0.4-4.2)); and overweight or obesity (72%) was about 1.02-1.3 times less common (ORtotal-adj = 0.98 (95%CI 0.4-2.6); ORnon-breastcancer-index-adj = 0.8 (95%CI 0.3-2.7)). Similar associations between lifestyle and breast cancer are suggested for PHTS and the general population. Despite not being statistically significant, results are clinically relevant and suggest that awareness of the effects of lifestyle on patients' breast cancer risk is important.

Contralateral breast cancer risk in patients with breast cancer and a germline-BRCA1/2 pathogenic variant undergoing radiation

BACKGROUND

Radiation-induced secondary breast cancer (BC) may be a concern after radiation therapy (RT) for primary breast cancer (PBC), especially in young patients with germline (g)BRCA-associated BC who already have high contralateral BC (CBC) risk and potentially increased genetic susceptibility to radiation. We sought to investigate whether adjuvant RT for PBC increases the risk of CBC in patients with gBRCA1/2-associated BC.

METHODS

The gBRCA1/2 pathogenic variant carriers diagnosed with PBC were selected from the prospective International BRCA1/2 Carrier Cohort Study. We used multivariable Cox proportional hazards models to investigate the association between RT (yes vs no) and CBC risk. We further stratified for BRCA status and age at PBC diagnosis (<40 and >40 years). Statistical significance tests were 2-sided.

RESULTS

Of 3602 eligible patients, 2297 (64%) received adjuvant RT. Median follow-up was 9.6 years. The RT group had more patients with stage III PBC than the non-RT group (15% vs 3%, P < .001), received chemotherapy more often (81% vs 70%, P < .001), and received endocrine therapy more often (50% vs 35%, P < .001). The RT group had an increased CBC risk compared with the non-RT group (adjusted hazard ratio [HR] = 1.44; 95% confidence interval [CI] = 1.12 to 1.86). Statistical significance was observed in gBRCA2 (HR = 1.77; 95% CI = 1.13 to 2.77) but not in gBRCA1 pathogenic variant carriers (HR = 1.29; 95% CI = 0.93 to 1.77; P = .39 for interaction). In the combined gBRCA1/2 group, patients irradiated when they were younger than or older than 40 years of age at PBC diagnosis showed similar risks (HR = 1.38; 95% CI = 0.93 to 2.04 and HR = 1.56; 95% CI = 1.11 to 2.19, respectively).

CONCLUSIONS

RT regimens minimizing contralateral breast dose should be considered in gBRCA1/2 pathogenic variant carriers.

Modifiable risk factors in women at high risk of breast cancer: a systematic review

BACKGROUND

Modifiable risk factors (alcohol, smoking, obesity, hormone use, and physical activity) affect a woman's breast cancer (BC) risk. Whether these factors affect BC risk in women with inherited risk (family history, BRCA1/2 mutations, or familial cancer syndrome) remains unclear.

METHODS

This review included studies on modifiable risk factors for BC in women with inherited risk. Pre-determined eligibility criteria were used and relevant data were extracted.

RESULTS

The literature search resulted in 93 eligible studies. For women with family history, most studies indicated that modifiable risk factors had no association with BC and some indicated decreased (physical activity) or increased risk (hormonal contraception (HC)/menopausal hormone therapy (MHT), smoking, alcohol). For women with BRCA mutations, most studies reported no association between modifiable risk factors and BC; however, some observed increased (smoking, MHT/HC, body mass index (BMI)/weight) and decreased risk (alcohol, smoking, MHT/HC, BMI/weight, physical activity). However, measurements varied widely among studies, sample sizes were often small, and a limited number of studies existed.

CONCLUSIONS

An increasing number of women will recognize their underlying inherited BC risk and seek to modify that risk. Due to heterogeneity and limited power of existing studies, further studies are needed to better understand how modifiable risk factors influence BC risk in women with inherited risk.

Physical Activity in Young BRCA Carriers and Reduced Risk of Breast Cancer

INTRODUCTION

A systematic literature review was conducted to determine whether physical activity levels during adolescent and young adult years were associated with a reduced lifetime risk of breast cancer among carriers of deleterious mutations in BRCA1 and BRCA2 genes.

METHODS

Ovid/MEDLINE, Embase, CENTRAL, WOS, and CINAHL were searched for articles including information about adolescent and young adult physical activity and breast cancer incidence among women carrying deleterious BRCA1 and BRCA2 gene mutations (search was initiated in October 2019; last update and full analyses were in March 2021). Independent reviewers screened articles at the title/abstract and full-text levels, resolving differences by consensus with lead authors. The NIH Quality Assessment Tools were used to assess sources of bias.

RESULTS

A total of 1,957 unique articles were identified; 5 met inclusion criteria. Samples size ranged from 68 to 1,185. All studies relied on self-reported adolescent and young adult physical activity. One study measured sports involvement; the others measured recreational activity. One large study was null, whereas 4 others showed a reduction in breast cancer incidence later in life with higher adolescent and young adult physical activity (p≤0.05). However, the protection was limited to premenopausal breast cancer in 1 of the studies (OR=0.62; 95% CI=0.40, 0.96; p-trend=0.01). In addition, adolescent and young adult physical activity was associated with older age at breast cancer diagnosis in 1 study (p=0.03).

CONCLUSIONS

A limited number of studies suggest that adolescent and young adult physical activity may reduce or delay the risk of breast cancer incidence among carriers of deleterious mutations in BRCA1 and BRCA2 genes.

PredictCBC-2.0: a contralateral breast cancer risk prediction model developed and validated in ~ 200,000 patients

BACKGROUND

Prediction of contralateral breast cancer (CBC) risk is challenging due to moderate performances of the known risk factors. We aimed to improve our previous risk prediction model (PredictCBC) by updated follow-up and including additional risk factors.

METHODS

We included data from 207,510 invasive breast cancer patients participating in 23 studies. In total, 8225 CBC events occurred over a median follow-up of 10.2 years. In addition to the previously included risk factors, PredictCBC-2.0 included CHEK2 c.1100delC, a 313 variant polygenic risk score (PRS-313), body mass index (BMI), and parity. Fine and Gray regression was used to fit the model. Calibration and a time-dependent area under the curve (AUC) at 5 and 10 years were assessed to determine the performance of the models. Decision curve analysis was performed to evaluate the net benefit of PredictCBC-2.0 and previous PredictCBC models.

RESULTS

The discrimination of PredictCBC-2.0 at 10 years was higher than PredictCBC with an AUC of 0.65 (95% prediction intervals (PI) 0.56-0.74) versus 0.63 (95%PI 0.54-0.71). PredictCBC-2.0 was well calibrated with an observed/expected ratio at 10 years of 0.92 (95%PI 0.34-2.54). Decision curve analysis for contralateral preventive mastectomy (CPM) showed the potential clinical utility of PredictCBC-2.0 between thresholds of 4 and 12% 10-year CBC risk for BRCA1/2 mutation carriers and non-carriers.

CONCLUSIONS

Additional genetic information beyond BRCA1/2 germline mutations improved CBC risk prediction and might help tailor clinical decision-making toward CPM or alternative preventive strategies. Identifying patients who benefit from CPM, especially in the general breast cancer population, remains challenging.

Progression-free survival and overall survival after BRCA1/2-associated epithelial ovarian cancer: A matched cohort study

Introduction

Germline BRCA1/2-associated epithelial ovarian cancer has been associated with better progression-free survival and overall survival than sporadic epithelial ovarian cancer, but conclusive data are lacking.

Methods

We matched 389 BRCA1-associated and 123 BRCA2-associated epithelial ovarian cancer patients 1:1 to sporadic epithelial ovarian cancer patients on year of birth, year of diagnosis, and FIGO stage (< = IIA/> = IIB). Germline DNA test was performed before or after epithelial ovarian cancer diagnosis. All patients received chemotherapy. We used Cox proportional hazards models to estimate the associations between mutation status (BRCA1 or BRCA2 versus sporadic) and progression-free survival and overall survival. To investigate whether DNA testing after epithelial ovarian cancer diagnosis resulted in survival bias, we performed additional analyses limited to BRCA1/2-associated epithelial ovarian cancer patients with a DNA test result before cancer diagnosis (n = 73 BRCA1; n = 9 BRCA2) and their matched sporadic controls.

Results

The median follow-up was 4.4 years (range 0.1–30.1). During the first three years after epithelial ovarian cancer diagnosis, progression-free survival was better for BRCA1 (HR 0.88, 95% CI 0.74–1.04) and BRCA2 (HR 0.58, 95% CI 0.41–0.81) patients than for sporadic patients. Overall survival was better during the first six years after epithelial ovarian cancer for BRCA1 (HR 0.7, 95% CI 0.58–0.84) and BRCA2 (HR 0.41, 95% CI 0.29–0.59) patients. After surviving these years, survival benefits disappeared or were in favor of the sporadic patients.

Conclusion

For epithelial ovarian cancer patients who received chemotherapy, we confirmed survival benefit for BRCA1 and BRCA2 germline pathogenic variant carriers. This may indicate higher sensitivity to chemotherapy, both in first line treatment and in the recurrent setting. The observed benefit appears to be limited to a relatively short period after epithelial ovarian cancer diagnosis.

Physical activity and sleep behaviour in women carrying BRCA1/2 mutations

The aim of the present study is to explore the potential association between sleep quality and physical activity (PA) in women carriers of BRCA1/2 mutations. 63 women completed the Pittsburgh Sleep Quality Index (PSQI) and Godin Shepard Leisure-Time Physical Activity Questionnaire (GSL-TPAQ) and were included in the present cross-sectional analysis. Globally, women showed a PSQI score of 7.0 ± 3.6 and a GSL-TPAQ score of 22.8 ± 18.3. Good sleepers (PSQI score ≤ 5) showed significantly higher PA levels compared to bad sleepers (PSQI score > 5). Women in the higher tertile of GSL-TPAQ total score (≥ 27 METs/week) have a prevalence ratio (PR) of being a good sleeper of 2.85 (1.25-6.52, 95% confidence intervals) compared to women in the lower tertile (≤ 11 METs/week). These results were consistent in BRCA1 and BRCA2 women. Considering each single question of PA intensity, the PR of being a good sleeper by unit of increase of MET/week was higher and significant in women engaged in strenuous and moderate intensity PA. These results suggests a direct association between PA and sleep quality in women carriers of BRCA mutations.

Survival of BRCA1/BRCA2-associated pT1 breast cancer patients, a cohort study

Purpose

Intensive screening in BRCA1/2 mutation carriers aims to improve breast cancer (BC) prognosis. Our aim is to clarify the prognostic impact of tumor size in BRCA mutation carriers with a pT1 BC, which is currently unclear. We are especially interested in differences between pT1a, pT1b, and pT1c regarding the prognosis of node-negative breast cancer, the effect of chemotherapy, and the prevalence of lymph node involvement.

Methods

For this study, BRCA1/2-associated BC patients were selected from a nationwide cohort. Primary outcomes were 10-year overall survival (OS) per pT1a-b-c group and the effect of chemotherapy on prognosis of node-negative BC, using Kaplan–Meier and Cox models. Finally, we evaluated lymph node involvement per pT1a-b-c group.

Results

963 women with pT1 BRCA1/2-associated BC diagnosed between 1990 and 2017 were included, of which 679 had pN0 BC. After a median follow-up of 10.5 years, 10-year OS in patients without chemotherapy was 77.1% in pT1cN0 and lower than for pT1aN0 (91.4%, p = 0.119) and pT1bN0 (90.8%, p = 0.024). OS was better with than without chemotherapy for pT1cN0 (91.6% vs. 77.1%, p = 0.001; hazard ratio (HR) 0.56, 95% confidence interval (CI): 0.21–1.48). Lymph node involvement was 24.9% in pT1c, 18.8% in pT1b, and 8.6% in pT1a.

Conclusion

Smaller tumor size is associated with better OS and less lymph node involvement in pT1 BRCA1/2-associated BC patients. The results suggest that early detection in BRCA1/2 mutation carriers of pT1a/b BC may reduce mortality and the need for systemic therapy.

Supplementary Information

The online version of this article contains supplementary material available (10.1007/s10549-022-06608-1.

Oral Contraceptive Use in BRCA1 and BRCA2 Mutation Carriers: Absolute Cancer Risks and Benefits

BACKGROUND

To help BRCA1 and 2 mutation carriers make informed decisions regarding use of combined-type oral contraceptive preparation (COCP), absolute risk-benefit estimates are needed for COCP-associated cancer.

METHODS

For a hypothetical cohort of 10 000 women, we calculated the increased or decreased cumulative incidence of COCP-associated (breast, ovarian, endometrial) cancer, examining 18 scenarios with differences in duration and timing of COCP use, uptake of prophylactic surgeries, and menopausal hormone therapy.

RESULTS

COCP use initially increased breast cancer risk and decreased ovarian and endometrial cancer risk long term. For 10 000 BRCA1 mutation carriers, 10 years of COCP use from age 20 to 30 years resulted in 66 additional COCP-associated cancer cases by the age of 35 years, in addition to 625 cases expected for never users. By the age of 70 years such COCP use resulted in 907 fewer cancer cases than the expected 9093 cases in never users. Triple-negative breast cancer estimates resulted in 196 additional COCP-associated cases by age 40 years, in addition to the 1454 expected. For 10 000 BRCA2 mutation carriers using COCP from age 20 to 30 years, 80 excess cancer cases were estimated by age 40 years in addition to 651 expected cases; by the age of 70 years, we calculated 382 fewer cases compared with the 6156 cases expected. The long-term benefit of COCP use diminished after risk-reducing bilateral salpingo-oophorectomy followed by menopausal hormone therapy use.

CONCLUSION

Although COCP use in BRCA1 and BRCA2 mutation carriers initially increases breast, ovarian, and endometrial cancer risk, it strongly decreases lifetime cancer risk. Risk-reducing bilateral salpingo-oophorectomy and menopausal hormone therapy use appear to counteract the long-term COCP-benefit.

Predictors of cardiopulmonary fitness in cancer-affected and -unaffected women with a pathogenic germline variant in the genes BRCA1/2 (LIBRE-1)

Physical activity (PA) helps prevention and aftercare of sporadic breast cancer (BC), cardiopulmonary fitness (CPF) being an age-independent predictor of tumor-specific mortality. Therefore, we wanted to identify predictors of CPF (represented by peak oxygen uptake: VO_2peak) in BRCA1/2 mutation carriers whose risk of developing BC is high. We used cross-sectional data from 68 BRCA1/2 germline mutation carrying women participating in the randomized, prospective, controlled clinical study LIBRE-1. Assessments included cardiopulmonary exercise testing, medical and lifestyle history plus socioeconomic status. Additionally, the participants completed a psychological questionnaire regarding their attitude, subjective norms, perceived behavior control and intention towards PA. A multivariate logistic regression model was used to identify predictors for participants reaching their age- and sex-adjusted VO_2peak reference values. 22 participants (median age: 40 years, interquartile range (IQR) 33–46) were cancer-unaffected and 46 cancer-affected (median age: 44 years, IQR 35–50). The strongest predictor for reaching the reference VO_2peak value was attitude towards PA (Odds Ratio 3.0; 95% Confidence Interval 1.3–8.4; p = 0.021). None of the other predictors showed a significant association. A positive attitude towards PA seems to be associated with VO_2peak, which should be considered in developing therapeutic and preventive strategies.

Trial registrations: NCT02087592; DRKS00005736.

Effects of chemotherapy on contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers: A nationwide cohort study

Aim

BRCA1/2 mutation carriers with primary breast cancer (PBC) are at high risk of contralateral breast cancer (CBC). In a nationwide cohort, we investigated the effects of chemotherapeutic agents given for PBC on CBC risk separately in BRCA1 and BRCA2 mutation carriers.

Patients and methods

BRCA1 or BRCA2 mutation carriers with an invasive PBC diagnosis from 1990 to 2017 were selected from a Dutch cohort. We estimated cumulative CBC incidence using competing risks analysis. Hazard ratios (HR) for the effect of neo-adjuvant or adjuvant chemotherapy and different chemotherapeutic agents on CBC risk were estimated using Cox regression.

Results

We included 1090 BRCA1 and 568 BRCA2 mutation carriers; median follow-up was 8.9 and 8.4 years, respectively. Ten-year cumulative CBC incidence for treatment with and without chemotherapy was 6.7% [95%CI: 5.1–8.6] and 16.7% [95%CI: 10.8–23.7] in BRCA1 and 4.8% [95%CI: 2.7–7.8] and 16.0% [95%CI: 9.3–24.4] in BRCA2 mutation carriers, respectively. Chemotherapy was associated with reduced CBC risk in BRCA1 (multivariable HR: 0.46, 95%CI: 0.29–0.74); a similar trend was observed in BRCA2 mutation carriers (HR: 0.63, 95%CI: 0.29–1.39). In BRCA1, risk reduction was most pronounced in the first 5 years (HR: 0.32, 95%CI: 0.17–0.61). Anthracyclines and the combination of anthracyclines with taxanes were associated with substantial CBC risk reduction in BRCA1 carriers (HR: 0.34, 95%CI: 0.17–0.68 and HR: 0.22, 95%CI: 0.08–0.62, respectively).

Conclusion

Risk-reducing effects of chemotherapy are substantial for at least 5 years and may be used in personalised CBC risk prediction in any case for BRCA1 mutation carriers.

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Contralateral breast cancer (CBC) risk is high in BRCA1/2 mutation carriers.

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Chemotherapy for primary breast cancer results in decreased CBC risk in BRCA1.

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Anthracyclines with/without taxanes show the largest CBC risk reduction in BRCA1.

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For BRCA2 similar trends are observed as in BRCA1 mutation carriers.

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Chemotherapy must be considered in personalised CBC risk models.

Why exercise has a crucial role in cancer prevention, risk reduction and improved outcomes

INTRODUCTION

Exercise is one of several factors known to lower the risk of developing cancer, as well as improve outcomes in patients already diagnosed. People who exercise after cancer have lower rates of cancer complications, treatment toxicities, relapse and improved survival. This review highlights the supportive data and biochemical processes, which explain these potential benefits.

SOURCES OF DATA

PubMed, Embase, Medline and Cochrane libraries were searched for papers which addressed the effects of exercise and physical activity on cancer for this review. The search terms used were physical activity, exercise and cancer up to February 2021. We also referred to the background research required for international exercise intervention study involving men with prostate cancer (INTERVAL-GAP4) and scrutinized references within the robust papers published on this subject to ensure we did not miss any clinically studies. One hundred and eighty eight papers were included.

AREAS OF AGREEMENT

Exercise programmes mitigate many of the complications and risks associated with cancer, particularly thromboembolism, fatigue, weight gain, arthralgia, cognitive impairment and depression.

AREAS OF CONTROVERSY

Molecular and biomarker changes, resulting from exercise, suggest that exercise elicits beneficial changes in insulin-related pathways, down-regulates inflammation and serum oestrogen levels, and enhances oxidative, immune and cellular repair pathways. Nonetheless, the evidence remains preliminary.

GROWING POINTS

The timing, intensity and challenges of prehabilitation, adjunct and rehabilitation exercise programmes are being increasingly understood but their implementation remains sporadic.

AREAS FOR DEVELOPING RESEARCH

More robust clinical trial data are needed to substantiate a causal effect of exercise on overall and cancer-specific survival. These studies are ongoing. Research evaluating the most cost-efficient ways of incorporating prehabilitation, adjunct and rehabilitation programmes into routine practice would be helpful to funding bodies and health care strategists.

Dose-dependent effects of aerobic exercise on clinically relevant biomarkers among healthy women at high genetic risk for breast cancer: A secondary analysis of a randomized controlled study

BACKGROUND

Excess adiposity and dysregulated metabolism are associated with increased cancer risk. Triglycerides, cholesterol, glucose, insulin, HOMA-IR, and VO₂ max are robust clinical-metabolic biomarkers of overall health.

AIMS

Aerobic exercise may improve clinical-metabolic biomarkers and decrease cancer risk. This secondary analysis of the WISER Sister randomized controlled trial investigated dose-dependent effects of aerobic exercise on clinical biomarker levels in women at high genetic risk for breast cancer.

METHODS AND RESULTS

One hundred thirty-nine participants were randomized to: control (<75 min/week), low-dose (150 min/week), and high-dose (300 min/week) aerobic exercise intervention groups. Intervention adherence was assessed via heart monitor. Fasting blood draws, cardio-pulmonary tests, and demographical surveys were taken at baseline and 5 months. Triglyceride, cholesterol, glucose, insulin, and VO₂ max changes were assessed for 80 of the 122 study completers. Ninety-six percent of assayed-completers adhered to >80% of their exercise dose. A significant dose-dependent increase in VO₂ max was observed for the low-dose and high-dose groups compared to control. No intervention effects were observed for plasma biomarkers. Overweight women (BMI > 25) showed a significant decrease in insulin levels and a trend for decreased triglycerides following exercise intervention. Significant increases in VO₂ max were independent of BMI stratification.

CONCLUSION

Women at high genetic risk for breast cancer should maintain healthy weights and aerobic capacities through aerobic exercise to achieve measurable benefits on overall health. For overweight women, exercise appears to improve subclinical metabolic dysregulation. However, normal weight women were unaffected by aerobic exercise as their biomarker levels may be below the threshold for improvement. VO₂ max increases solely quantified the benefits of exercise in already healthy women at high-risk for breast cancer.

Increased Duration of Exercise Decreases Rate of Nonresponse to Exercise but May Not Decrease Risk for Cancer Mortality

INTRODUCTION

Previous studies have observed an inverse relationship between exercise and breast cancer risk. However, there is interindividual variability in response to exercise training interventions. We investigated whether increasing the dose of aerobic exercise (150 or 300 min·wk-1), while keeping intensity of exercise constant (70%-80% HRmax), decreases the number of exercise nonresponders and further decreases associated risk for cancer mortality in our study population of women genetically predisposed for breast cancer.

METHODS

Healthy premenopausal women at elevated risk of breast cancer were randomized into control (<75 min·wk-1, n = 47), low-dose exercise (150 min·wk-1, n = 39), and high-dose exercise groups (300 min·wk-1, n = 39) for approximately 6 months. We assessed 1) clinical effectiveness (CE), defined as an improvement in predicted V˙O2max of ≥1 mL·kg-1·min-1, and twice the typical error (2× TE) of V˙O2max as thresholds to classify exercise "nonresponders"; 2) CE and 2× TE relative to exercise adherence levels; and 3) related changes in V˙O2max to predicted cancer mortality risk.

RESULTS

After our 6-month intervention, we observed that 23.5% of women in the low-dose group and 5.6% of women in the high-dose group were clinical nonresponders (P = 0.04). Clinical nonresponder status was independent of adherence level. Associated reduction in risk for cancer mortality was observed among 87.2% of women in the low-dose group and 94.9% in the high-dose group (P = 0.43).

CONCLUSION

Increasing volume (not intensity) of exercise via time spent exercising significantly decreases the number of "nonresponders." True nonresponders were observed as some women did not improve their fitness capacity despite high exercise adherence levels. Lastly, it appears 150 min·wk-1 is sufficient to decrease the predicted risk of cancer mortality.

Obesity and liver cancer

Obesity prevalence is rapidly increasing worldwide. It is associated with huge economic and health costs due to its clinical consequences, which includes increased incidence of type 2 diabetes, cardiovascular diseases, and development of different malignancies. In particular, obesity is an independent risk factor for the development of hepatocellular carcinoma (HCC). Indeed, obesity is highly prevalent in patients with non-alcoholic fatty liver disease (NAFLD) that is becoming one of the most frequent causes of liver disease worldwide. NAFLD-related HCC is the most rapidly growing indication for liver transplantation in many countries. The higher mortality rates found in obese HCC patients might be related not only to a worse outcome after HCC treatments, but also to a delayed diagnosis related to a low frequency and a poorer quality of abdominal ultrasonography surveillance that is the test universally used for HCC screening. Given its diffusion, obesity is frequently present in patients with chronic liver diseases related to different etiologies, and in these cases it may increase the HCC risk, acting as an additional co-factor. Indeed, growing evidence demonstrates that a healthy diet and regular physical activity may have an impact in reducing the overall HCC risk. Finally, an impact of obesity in the development of intrahepatic cholangiocarcinoma has been postulated, but more extensive studies are needed to definitively confirm this association.

Influence of physical activity at a young age and lifetime physical activity on the risks of 3 obesity-related cancers: systematic review and meta-analysis of observational studies

CONTEXT

Excess weight has been linked to increased risks of 13 types of cancers. Physical activity is a non-nutritional modifiable lifestyle factor that is not only crucial for weight control but is also known to regulate hormones and metabolic pathways that may contribute to carcinogenesis. There is solid evidence that being physically active during middle and late adulthood lowers the risks of 3 obesity-related cancers, namely breast cancer, colon cancer, and endometrial cancer. However, the associations between physical activity at a young age (childhood, adolescence, and young adulthood; age 5 to ≤30 yr) and lifetime physical activity and the risks of breast cancer, colon cancer, and endometrial cancer are less defined.

OBJECTIVE

The present systematic review and meta-analysis of observational studies was performed in accordance with the MOOSE guidelines to determine whether physical activity at a young age and lifetime physical activity may lower the risks of breast cancer, colon cancer, and endometrial cancer.

DATA SOURCES

The PubMed and Web of Science databases were searched for relevant observational studies published from inception to July 2018.

STUDY SELECTION

Observational studies (prospective cohort, case-cohort, nested case-control, historical cohort, and case-control) were considered relevant if they investigated the association between physical activity at a young age or lifetime physical activity and the risks of developing selected cancers.

DATA EXTRACTION

A random-effects meta-analysis was performed to generate the summary relative risk (RR) with 95%CI for the highest vs the lowest category of physical activity of any type.

RESULTS

Eighty publications were included in the present meta-analysis. Higher physical activity at a young age was associated with lower risks of breast cancer (RR 0.81, 95%CI 0.76, 0.87) and colon cancer (RR 0.67, 95%CI 0.50, 0.88). Similarly, lifetime physical activity was inversely associated with the risks of breast cancer (RR 0.79, 95%CI 0.72, 0.86) and colon cancer (RR 0.75, 95%CI 0.69, 0.82). For breast cancer, menopausal status did not appear to modify the observed inverse association. The benefit with respect to endometrial cancer risk reduction was only observed with higher lifetime physical activity (RR 0.77, 95%CI 0.67, 0.88), not with higher physical activity at a young age (RR 0.89, 95%CI 0.73, 1.07).

CONCLUSIONS

Being physically active over a lifetime, starting from early childhood, may lower the risks of developing breast cancer, colon cancer, and endometrial cancer.

Beneficial Molecular Adaptations In BRCA-Mutation Carriers By Combined HIT/HIRT Intervention: Results From A Pilot Study

Based on growing evidence that breast cancer (BRCA) also plays a pivotal role in the regulation of skeletal muscle metabolism and the response to anti-oxidative stress, we examined the influence of regular exercise in human BRCA mutation carriers on their BRCA1 gene/protein expression and inflammatory/oxidative response. Sixteen BRCA-mutation carriers were assigned to an intervention (IG) or control group (CG). IG received a combination of high-intensity interval endurance (HIT) and strength training (HIRT) for six weeks, whereas CG received a low-intensity activity program. Before (T0) and at the end of the intervention (T1), muscle biopsy, physiological performance, blood withdrawal and anthropometry were obtained. Parameters included: Muscle BRCA1 gene/protein expression, inflammatory/oxidative stress, anti-oxidative capacity, peak oxygen capacity (VO₂peak) and 1-repetition maximum (1-RM) at six different training machines. VO₂peak and 1-RM of IG were increased at T1 compared to T0, whereas CG performance, physiological and molecular parameters remained unchanged. IG showed increased BRCA1 protein concentration as well as anti-oxidative capacity, whereas gene expression was unaltered. IG inflammatory and oxidative damage did not differ between time points. Combined HIT/HIRT increases aerobic and strength performance of BRCA-mutation carriers with up regulated BRCA1 protein expression and improved anti-oxidative status without showing an increased inflammatory response.

The supplemental value of mammographic screening over breast MRI alone in BRCA2 mutation carriers

Purpose

BRCA2 mutation carriers are offered annual breast screening with MRI and mammography. The aim of this study was to investigate the supplemental value of mammographic screening over MRI screening alone.

Methods

In this multicenter study, proven BRCA2 mutation carriers, who developed breast cancer during screening using both digital mammography and state-of-art breast MRI, were identified. Clinical data were reviewed to classify cases in screen-detected and interval cancers. Imaging was reviewed to assess the diagnostic value of mammography and MRI, using the Breast Imaging and Data System (BI-RADS) classification allocated at the time of diagnosis.

Results

From January 2003 till March 2019, 62 invasive breast cancers and 23 ductal carcinomas in situ were diagnosed in 83 BRCA2 mutation carriers under surveillance. Overall screening sensitivity was 95.2% (81/85). Four interval cancers occurred (4.7% (4/85)). MRI detected 73 of 85 breast cancers (sensitivity 85.8%) and 42 mammography (sensitivity 49.9%) (p < 0.001).

Eight mammography-only lesions occurred. In 1 of 17 women younger than 40 years, a 6-mm grade 3 DCIS, retrospectively visible on MRI, was detected with mammography only in a 38-year-old woman. The other 7 mammography-only breast cancers were diagnosed in women aged 50 years and older, increasing sensitivity in this subgroup from 79.5% (35/44) to 95.5% (42/44) (p ≤ 0.001).

Conclusions

In BRCA2 mutation carriers younger than 40 years, the benefit of mammographic screening over MRI was very small. In carriers of 50 years and older, mammographic screening contributed significantly. Hence, we propose to postpone mammographic screening in BRCA2 mutation carriers to at least age 40.

Diet, weight management, physical activity and Ovarian & Breast Cancer Risk in women with BRCA1/2 pathogenic Germline gene variants: systematic review

Introduction

Women with pathogenic germline gene variants in BRCA1 and/or BRCA2 are at increased risk of developing ovarian and breast cancer. While surgical and pharmacological approaches are effective for risk-reduction, it is unknown whether lifestyle approaches such as healthful dietary habits, weight management, and physical activity may also contribute to risk-reduction. We conducted a systematic review of evidence related to dietary habits, weight status/change, and physical activity on ovarian and breast cancer risk among women with BRCA1/2 pathogenic variants.

Methods

We searched Medline, EMBASE, CENTRAL, PubMed, and clinicaltrials.gov up to October 3, 2019. We identified 2775 records and included 21.

Results

There is limited evidence related to these factors and ovarian cancer risk. For breast cancer risk, evidence suggests higher diet quality, adulthood weight-loss of ≥10 pounds, and activity during adolescence and young-adulthood may be linked with decreased risk. Higher meat intake and higher daily energy intake may be linked with increased risk.

Conclusions

There is not enough evidence to suggest tailored recommendations for dietary habits or weight management among women with BRCA1/2 pathogenic variants compared to the general population for ovarian and breast cancer risk-reduction, and physical activity recommendations should remain the same.

Recreational Physical Activity Is Associated with Reduced Breast Cancer Risk in Adult Women at High Risk for Breast Cancer: A Cohort Study of Women Selected for Familial and Genetic Risk

Although physical activity is associated with lower breast cancer risk for average-risk women, it is not known if this association applies to women at high familial/genetic risk. We examined the association of recreational physical activity (self-reported by questionnaire) with breast cancer risk using the Prospective Family Study Cohort, which is enriched with women who have a breast cancer family history (N = 15,550). We examined associations of adult and adolescent recreational physical activity (quintiles of age-adjusted total metabolic equivalents per week) with breast cancer risk using multivariable Cox proportional hazards regression, adjusted for demographics, lifestyle factors, and body mass index. We tested for multiplicative interactions of physical activity with predicted absolute breast cancer familial risk based on pedigree data and with BRCA1 and BRCA2 mutation status. Baseline recreational physical activity level in the highest four quintiles compared with the lowest quintile was associated with a 20% lower breast cancer risk (HR, 0.80; 95% confidence interval, 0.68-0.93). The association was not modified by familial risk or BRCA mutation status (P interactions >0.05). No overall association was found for adolescent recreational physical activity. Recreational physical activity in adulthood may lower breast cancer risk for women across the spectrum of familial risk. SIGNIFICANCE: These findings suggest that physical activity might reduce breast cancer risk by about 20% for women across the risk continuum, including women at higher-than-average risk due to their family history or genetic susceptibility.See related commentary by Niehoff et al., p. 23.

Use of Endocrine Therapy for Breast Cancer Risk Reduction: ASCO Clinical Practice Guideline Update

PURPOSE

To update the ASCO guideline on pharmacologic interventions for breast cancer risk reduction and provide guidance on clinical issues that arise when deciding to use endocrine therapy for breast cancer risk reduction.

METHODS

An Expert Panel conducted targeted systematic literature reviews to identify new studies.

RESULTS

A randomized clinical trial that evaluated the use of anastrozole for reduction of estrogen receptor–positive breast cancers in postmenopausal women at increased risk of developing breast cancer provided the predominant basis for the update.

UPDATED RECOMMENDATIONS

In postmenopausal women at increased risk, the choice of endocrine therapy now includes anastrozole (1 mg/day) in addition to exemestane (25 mg/day), raloxifene (60 mg/day), or tamoxifen (20 mg/day). The decision regarding choice of endocrine therapy should take into consideration age, baseline comorbidities, and adverse effect profiles. Clinicians should not prescribe anastrozole, exemestane, or raloxifene for breast cancer risk reduction to premenopausal women. Tamoxifen 20 mg/day for 5 years is still considered standard of care for risk reduction in premenopausal women who are at least 35 years old and have completed childbearing. Data on low-dose tamoxifen as an alternative to the standard dose for both pre- and postmenopausal women with intraepithelial neoplasia are discussed in the Clinical Considerations section of this article. Additional information is available at www.asco.org/breast-cancer-guidelines .

Germline BRCA-Associated Endometrial Carcinoma Is a Distinct Clinicopathologic Entity

PURPOSE

Whether endometrial carcinoma (EC) should be considered part of the gBRCA1/2-associated hereditary breast and ovarian cancer (HBOC) syndrome is topic of debate. We sought to assess whether ECs occurring in gBRCA carriers are enriched for clinicopathologic and molecular characteristics, thereby supporting a causal relationship.

EXPERIMENTAL DESIGN

Thirty-eight gBRCA carriers that developed EC were selected from the nationwide cohort study on hereditary breast and ovarian cancer in the Netherlands (HEBON), and these were supplemented with four institutional cases. Tumor tissue was retrieved via PALGA (Dutch Pathology Registry). Nineteen morphologic features were scored and histotype was determined by three expert gynecologic pathologists, blinded for molecular analyses (UCM-OncoPlus Assay including 1213 genes). ECs with LOH of the gBRCA-wild-type allele (gBRCA/LOHpos) were defined "gBRCA-associated," those without LOH (gBRCA/LOHneg) were defined "sporadic."

RESULTS

LOH could be assessed for 40 ECs (30 gBRCA1, 10 gBRCA2), of which 60% were gBRCA/LOHpos. gBRCA/LOHpos ECs were more frequently of nonendometrioid (58%, P = 0.001) and grade 3 histology (79%, P < 0.001). All but two were in the TP53-mutated TCGA-subgroup (91.7%, P < 0.001). In contrast, gBRCA/LOHneg ECs were mainly grade 1 endometrioid EC (94%) and showed a more heterogeneous distribution of TCGA-molecular subgroups: POLE-mutated (6.3%), MSI-high (25%), NSMP (62.5%), and TP53-mutated (6.3%).

CONCLUSIONS

We provide novel evidence in favor of EC being part of the gBRCA-associated HBOC-syndrome. gBRCA-associated ECs are enriched for EC subtypes associated with unfavorable clinical outcome. These findings have profound therapeutic consequences as these patients may benefit from treatment strategies such as PARP inhibitors. In addition, it should influence counseling and surveillance of gBRCA carriers.

Survival after bilateral risk-reducing mastectomy in healthy BRCA1 and BRCA2 mutation carriers

Background

In healthy BRCA1/2 mutation carriers, bilateral risk-reducing mastectomy (BRRM) strongly reduces the risk of developing breast cancer (BC); however, no clear survival benefit of BRRM over BC surveillance has been reported yet.

Methods

In this Dutch multicenter cohort study, we used multivariable Cox models with BRRM as a time-dependent covariable to estimate the associations between BRRM and the overall and BC-specific mortality rates, separately for BRCA1 and BRCA2 mutation carriers.

Results

During a mean follow-up of 10.3 years, 722 out of 1712 BRCA1 (42%) and 406 out of 1145 BRCA2 (35%) mutation carriers underwent BRRM. For BRCA1 mutation carriers, we observed 52 deaths (20 from BC) in the surveillance group, and 10 deaths (one from BC) after BRRM. The hazard ratios were 0.40 (95% CI 0.20–0.90) for overall mortality and 0.06 (95% CI 0.01–0.46) for BC-specific mortality. BC-specific survival at age 65 was 93% for surveillance and 99.7% for BRRM. For BRCA2 mutation carriers, we observed 29 deaths (7 from BC) in the surveillance group, and 4 deaths (no BC) after BRRM. The hazard ratio for overall mortality was 0.45 (95% CI 0.15–1.36). BC-specific survival at age 65 was 98% for surveillance and 100% for BRRM.

Conclusion

BRRM was associated with lower mortality than surveillance for BRCA1 mutation carriers, but for BRCA2 mutation carriers, BRRM may lead to similar BC-specific survival as surveillance. Our findings support a more individualized counseling based on BRCA mutation type.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05345-2) contains supplementary material, which is available to authorized users.

Elucidating the novel BRCA1 function as a non-genomic metabolic restraint in ER-positive breast cancer cell lines

Within populations carrying the same genetic predisposition, the penetrance of BRCA1 mutations has increased over time. Although linked to changes in lifestyle factors associated with energy metabolism, these observations cannot be explained by the established role of BRCA1 in DNA repair alone. We manipulated BRCA1 expression using tetracycline in the UBR60-bcl2 cell line (which has an inducible, tetracycline-regulated BRCA1 expression) and siRNA in oestrogen receptor(ER)-positive MCF7 and T47D breast cancer cells. Cellular responses to BRCA1 silencing and IGF-I actions were investigated using western blotting, 3-H Thymidine incorporation assay, cell fractionation and co-immunoprecipitation. We demonstrated that the loss of BRCA1 resulted in downregulation of a phosphorylated and inactive form of acetyl CoA Carboxylase-α (ACCA), with a concomitant increase in fatty acid synthase (FASN) abundance. BRCA1 was predominantly cytoplasmic in ER-positive breast cancer cells, compatible with the observation that BRCA1 physically associates with phosphorylated ACCA, which is a cytoplasmic protein. We also found that IGF-I induced de-phosphorylation of ACCA by reducing the interaction between BRCA1 and phosphorylated ACCA. BRCA1 deficiency enhanced the non-genomic effects of IGF-I, as well as the proliferative responses of cells to IGF-I. We characterized a novel, non-genomic role for BRCA1 in restraining metabolic activity and IGF-I anabolic actions.

Ovarian stimulation for IVF and risk of primary breast cancer in BRCA1/2 mutation carriers

BACKGROUND

The effect of in vitro fertilisation (IVF) on breast cancer risk for BRCA1/2 mutation carriers is rarely examined. As carriers may increasingly undergo IVF as part of preimplantation genetic diagnosis (PGD), we examined the impact of ovarian stimulation for IVF on breast cancer risk in BRCA1/2 mutation carriers.

METHODS

The study population consisted of 1550 BRCA1 and 964 BRCA2 mutation carriers, derived from the nationwide HEBON study and the nationwide PGD registry. Questionnaires, clinical records and linkages with the Netherlands Cancer Registry were used to collect data on IVF exposure, risk-reducing surgeries and cancer diagnosis, respectively. Time-dependent Cox regression analyses were conducted, stratified for birth cohort and adjusted for subfertility.

RESULTS

Of the 2514 BRCA1/2 mutation carriers, 3% (n = 76) were exposed to ovarian stimulation for IVF. In total, 938 BRCA1/2 mutation carriers (37.3%) were diagnosed with breast cancer. IVF exposure was not associated with risk of breast cancer (HR: 0.79, 95% CI: 0.46-1.36). Similar results were found for the subgroups of subfertile women (n = 232; HR: 0.73, 95% CI: 0.39-1.37) and BRCA1 mutation carriers (HR: 1.12, 95% CI: 0.60-2.09). In addition, age at and recency of first IVF treatment were not associated with breast cancer risk.

CONCLUSION

No evidence was found for an association between ovarian stimulation for IVF and breast cancer risk in BRCA1/2 mutation carriers.

Modifiable Lifestyle Factors: Opportunities for (Hereditary) Breast Cancer Prevention - a Narrative Review

Increasing rates of obesity, lack of physical activity, sedentary behavior, and frequent alcohol consumption are major lifestyle-related risk factors for breast cancer. In fact, it has been estimated that about one-third of breast cancer cases are attributable to factors women can change. Most research has focused on examining the impact of one single exposure on breast cancer risk while adjusting for other risk modifiers. Capitalizing on big data, major efforts have been made to evaluate the combined impact of well-established lifestyle factors on overall breast cancer risk. At the individual level, data indicate that even simple behavior modifications could have a considerable impact on breast cancer prevention. Moreover, there is emerging new evidence that adopting a healthy lifestyle may be particularly relevant for women with hereditary susceptibility to breast cancer. On the absolute risk scale, studies suggest that the presence of certain risk factors, such as excessive body weight, had a substantially higher impact on breast cancer risk if women had a hereditary predisposition to cancer. The existing body of knowledge gives the medical professionals guidance as to which factors to focus on when counseling patients. However, well-designed randomized controlled trials utilizing objective methods are crucial to providing concrete recommendations.

The association between cancer family history and ovarian cancer risk in BRCA1/2 mutation carriers: can it be explained by the mutation position?

This observational study aimed to investigate whether the reported association between family history (FH) of breast cancer (BC) or ovarian cancer (OC) and OC risks in BRCA1/2 mutation carriers can be explained by mutation position on the gene. In total, 3310 female BRCA1/2 mutation carriers participating in a nationwide prospective cohort (Hereditary Breast and Ovarian Cancer in the Netherlands) were included. FH was classified according to cancer occurrence in first-degree relatives (BC only, OC only, both, neither) and mutations were classified according to their position on the gene (OC cluster region (OCCR), BC cluster region, neither). The main outcome was OC occurrence. Cox proportional-hazard models were applied to investigate the association between FH and OC risks before and after adjusting for mutation position. Of all women included, 202 were diagnosed with OC. A BC-only FH tended to be associated with lower OC risks when compared with a FH without BC/OC (HR: 0.79, 95% CI: 0.52-1.17; HR: 0.59, 95% CI: 0.33-1.07 for BRCA1 and BRCA2, respectively) while an OC-only FH tended to be associated with higher risks (HR: 1.58, 95% CI: 0.90-2.77; HR: 1.75, 95% CI: 0.70-4.37 for BRCA1 and BRCA2, respectively). After adjusting for mutation position, association between FH and OC risks was slightly smaller in magnitude (HR: 0.85, 95% CI: 0.55-1.30; HR: 0.64, 95% CI: 0.34-1.21 for BC-only FH in BRCA1 and BRCA2, respectively; HR: 1.46, 95% CI: 0.80-2.68; HR: 1.49, 95% CI: 0.44-4.02 for OC-only FH in BRCA1 and BRCA2, respectively), indicating that mutation position explains only part of the association. Considering the magnitude of the observed trend, we do not believe FH should be used to change counseling regarding OC prevention.

Physical activity during adolescence and young adulthood and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Physical activity is inversely associated with the risk of breast cancer among women in the general population. It is not clear whether or not physical activity is associated with the risk of BRCA-associated breast cancer.

METHODS

We conducted a case-control study of 443 matched pairs of BRCA mutation carriers to evaluate the association between physical activity and breast cancer risk. Moderate and vigorous physical activities at ages 12-13, ages 14-17, ages 18-22, ages 23-29 and ages 30-34 were determined using the Nurses' Health Study II Physical Activity Questionnaire. We estimated mean metabolic equivalent task hours/week for moderate, vigorous and total physical activities overall (ages 12-34), during adolescence (ages 12-17) and during early adulthood (ages 18-34). Logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for total, moderate and strenuous recreational physical activities and breast cancer risk, by menopausal status.

RESULTS

Overall, there was no significant association between total physical activity and subsequent breast cancer risk (OR_{Q4 vs. Q1} = 1.01, 95% CI 0.69-1.47; P-trend = 0.72). Moderate physical activity between ages 12-17 was associated with a 38% decreased risk of premenopausal breast cancer (OR_{Q4 vs. Q1} = 0.62; 95% CI 0.40-0.96; P-trend = 0.01). We found no association between exercise and breast cancer diagnosed after menopause.

CONCLUSIONS

These findings suggest that early-life physical activity is associated with a reduced risk of premenopausal breast cancer among BRCA mutation carriers.

IMPACT

Future prospective analyses, complemented by mechanistic evidence, are warranted in this high-risk population.

Physical activity, sedentary behaviour, diet, and cancer: an update and emerging new evidence

The lifestyle factors of physical activity, sedentary behaviour, and diet are increasingly being studied for their associations with cancer. Physical activity is inversely associated with and sedentary behaviour is positively (and independently) associated with an increased risk of more than ten types of cancer, including colorectal cancer (and advanced adenomas), endometrial cancers, and breast cancer. The most consistent dietary risk factor for premalignant and invasive breast cancer is alcohol, whether consumed during early or late adult life, even at low levels. Epidemiological studies show that the inclusion of wholegrain, fibre, fruits, and vegetables within diets are associated with reduced cancer risk, with diet during early life (age <8 years) having the strongest apparent association with cancer incidence. However, randomised controlled trials of diet-related factors have not yet shown any conclusive associations between diet and cancer incidence. Obesity is a key contributory factor associated with cancer risk and mortality, including in dose-response associations in endometrial and post-menopausal breast cancer, and in degree and duration of fatty liver disease-related hepatocellular carcinoma. Obesity produces an inflammatory state, characterised by macrophages clustered around enlarged hypertrophied, dead, and dying adipocytes, forming crown-like structures. Increased concentrations of aromatase and interleukin 6 in inflamed breast tissue and an increased number of macrophages, compared with healthy tissue, are also observed in women with normal body mass index, suggesting a metabolic obesity state. Emerging randomised controlled trials of physical activity and dietary factors and mechanistic studies of immunity, inflammation, extracellular matrix mechanics, epigenetic or transcriptional regulation, protein translation, circadian disruption, and interactions of the multibiome with lifestyle factors will be crucial to advance this field.

Monitoring modifiable risk factors for breast cancer: an obligation for health professionals

Worldwide, breast cancer is the most common disease in women and constitutes the second leading cause of cancer death in this population. The factors that contribute to the risk of occurrence are divided into nonmodifiable and modifiable factors. Although there are interventions in primary care to prevent the disease, these measures have not produced the desired changes in women’s health. This article reviews the major modifiable risk factors for breast cancer and describes how these factors can affect the incidence of cancer in women. This information shows that modifiable risk factors (such as physical activity, diet, obesity, and use of alcohol and tobacco) can influence the occurrence of breast cancer, in part depending on the life stage of a woman, including menopausal status. Timely prevention at the primary care level is one of the most important areas on which health professionals need to focus in order to help reduce the incidence of breast cancer.

Exercise-induced biochemical changes and their potential influence on cancer: a scientific review

AIM

To review and discuss the available international literature regarding the indirect and direct biochemical mechanisms that occur after exercise, which could positively, or negatively, influence oncogenic pathways.

METHODS

The PubMed, MEDLINE, Embase and Cochrane libraries were searched for papers up to July 2016 addressing biochemical changes after exercise with a particular reference to cancer. The three authors independently assessed their appropriateness for inclusion in this review based on their scientific quality and relevance.

RESULTS

168 papers were selected and categorised into indirect and direct biochemical pathways. The indirect effects included changes in vitamin D, weight reduction, sunlight exposure and improved mood. The direct effects included insulin-like growth factor, epigenetic effects on gene expression and DNA repair, vasoactive intestinal peptide, oxidative stress and antioxidant pathways, heat shock proteins, testosterone, irisin, immunity, chronic inflammation and prostaglandins, energy metabolism and insulin resistance.

SUMMARY

Exercise is one of several lifestyle factors known to lower the risk of developing cancer and is associated with lower relapse rates and better survival. This review highlights the numerous biochemical processes, which explain these potential anticancer benefits.

The Mechanisms and Effects of Physical Activity on Breast Cancer

Breast cancer is the most common cancer in women. An extensive part of this health problem can be prevented by an active lifestyle. Physical activity can reduce the risk of breast cancer, reduce the rate of recurrence, and increase the survival rate of patients with breast cancer. The aim of this review was to summarize our current knowledge regarding the effects of physical activity on breast cancer risk, recurrence, and survival. Furthermore, we investigated 5 possible underlying mechanisms through which physical activity has an influence on breast cancer (ie, a reduction of sex hormones, metabolic hormones, adipokines and oxidative stress, and an improvement of the immune function). In this review, we give a complete overview of this subject.

Lifestyle Risk Factors for Breast Cancer in BRCA1/2-Mutation Carriers Around Childbearing Age

BRCA1/2-mutation carriers are at high risk of breast cancer (BC) and ovarian cancer. Physical inactivity, overweight (body mass index ≥25, BMI), smoking, and alcohol consumption are jointly responsible for about 1 in 4 postmenopausal BC cases in the general population. Limited evidence suggests physical activity also increases BC risk in BRCA1/2-mutation carriers. Women who have children often reduce physical activity and have weight gain, which increases BC risk. We assessed aforementioned lifestyle factors in a cohort of 268 BRCA1/2-mutation carriers around childbearing age (born between 1968 and 1983, median age 33 years, range 21–44). Furthermore, we evaluated the effect of having children on physical inactivity and overweight. Carriers were asked about lifestyle 4–6 weeks after genetic diagnosis at the Familial Cancer Clinic Nijmegen. Physical inactivity was defined as sports activity fewer than once a week. Carriers were categorized according to the age of their youngest child (no children, age 0–3 years and ≥4 years). In total, 48% of carriers were physically inactive, 41% were overweight, 27% smoked, and 70% consumed alcohol (3% ≥8 beverages/week). Physical inactivity was 4–5 times more likely in carriers with children. Overweight was not associated with having children. Carriers with children are a subgroup that may specifically benefit from lifestyle support to reduce BC risk.

Development and psychometric testing of a new instrument to measure factors influencing women's breast cancer prevention behaviors (ASSISTS)

BACKGROUND

Breast cancer preventive behaviors have an extreme effect on women's health. Despite the benefits of preventive behaviors regarding breast cancer, they have not been implemented as routine care for healthy women. To assess this health issue, a reliable and valid scale is needed. The aim of the present study is to develop and examine the psychometric properties of a new scale, called the ASSISTS, in order to identify factors that affect women's breast cancer prevention behaviors.

METHODS

A multi-phase instrument development method was performed to develop the questionnaire from February 2012 to September 2014. The item pool was generated based on secondary analyses of previous qualitative data. Then, content and face validity were applied to provide a pre-final version of the scale. The scale validation was conducted with a sample of women recruited from health centers affiliated with Tehran University of Medical Sciences. The construct validity (both exploratory and confirmatory), convergent validity, discriminate validity, internal consistency reliability and test-retest analysis of the questionnaire were tested.

RESULTS

Fifty-eight items were initially extracted from the secondary analysis of previous qualitative data. After content validity, this was reduced to 49 items. The exploratory factor analysis revealed seven factors (Attitude, supportive systems, self-efficacy, information seeking, stress management, stimulant and self-care) containing 33 items that jointly accounted for 60.62 % of the observed variance. The confirmatory factor analysis showed a model with appropriate fitness for the data. The Cronbach's alpha coefficient for the subscales ranged from 0.68 to 0.85, and the Intraclass Correlation Coefficient (ICC) ranged from 0.71 to 0.98; which is well above the acceptable thresholds.

CONCLUSION

The findings showed that the designed questionnaire was a valid and reliable instrument for assessing factors affecting women's breast cancer prevention behaviors that can be used both in practice and in future studies.

Timing of risk reducing mastectomy in breast cancer patients carrying a BRCA1/2 mutation: retrospective data from the Dutch HEBON study

It is expected that rapid genetic counseling and testing (RGCT) will lead to increasing numbers of breast cancer (BC) patients knowing their BRCA1/2 carrier status before primary surgery. Considering the potential impact of knowing one’s status on uptake and timing of risk-reducing contralateral mastectomy (RRCM), we aimed to evaluate trends over time in RRCM, and differences between carriers identified either before (predictively) or after (diagnostically) diagnosis. We collected data from female BRCA1/2 mutation carriers diagnosed with BC between 1995 and 2009 from four Dutch university hospitals. We compared the timing of genetic testing and RRCM in relation to diagnosis in 1995–2000 versus 2001–2009 for all patients, and predictively and diagnostically tested patients separately. Of 287 patients, 219 (76 %) had a diagnostic BRCA1/2 test. In this cohort, the median time from diagnosis to DNA testing decreased from 28 months for those diagnosed between 1995 and 2000 to 14 months for those diagnosed between 2001 and 2009 (p < 0.001). Similarly, over time women in this cohort underwent RRCM sooner after diagnosis (median of 77 vs. 27 months, p = 0.05). Predictively tested women who subsequently developed BC underwent an immediate RRCM significantly more often than women who had a diagnostic test (21/61, 34 %, vs. 13/170, 7.6 %, p < 0.001). Knowledge of carrying a BRCA1/2 mutation when diagnosed with BC influenced decisions concerning primary surgery. Additionally, in more recent years, women who had not undergone predictive testing were more likely to undergo diagnostic DNA testing and RRCM sooner after diagnosis. This suggests the need for RGCT to guide treatment decisions.

The Dose-Response Effects of Aerobic Exercise on Body Composition and Breast Tissue among Women at High Risk for Breast Cancer: A Randomized Trial

Observational data indicate that behaviors that shift energetic homeostasis, such as exercise, may decrease the risk of developing breast cancer by reducing the amount of energy-dense, metabolically active adipose tissue. Between December 2008 and April 2013, we conducted a single-blind, 5-month, clinical trial that randomized premenopausal women at high risk of developing breast cancer to one of three groups: 150 min/wk of aerobic exercise (low dose), 300 min/wk of aerobic exercise (high dose), or control. Body composition was assessed using dual-energy x-ray absorptiometry. Background parenchymal enhancement (BPE) was quantified using computerized algorithms on breast dynamic contrast-enhanced MRI. Over 5 months, compared with the control group: the low-dose and high-dose groups lost -1.5 ± 0.5 and -1.3 ± 0.5 kg of body mass (linear Ptrend = 0.032); -1.5 ± 0.4 and -1.4 ± 0.3 kg of fat mass (linear Ptrend = 0.003); -1.3 ± 0.3 and -1.4 ± 0.3% of body fat (linear Ptrend < 0.001); -15.9 ± 5.4 and -26.6 ± 5.0 cm(2) of subcutaneous adipose tissue (linear Ptrend < 0.001); and -6.6 ± 1.9 and -5.0 ± 1.9 cm(2) visceral adipose tissue (nonlinear Ptrend = 0.037). For each -1 cm(2) reduction in visceral adipose tissue, BPE decreased by -3.43 ± 1.34 cm(2) (P = 0.010) and explained 9.7% of the variability in BPE. Changes in other aforementioned body composition outcomes did not significantly correlate with changes in BPE. These mechanistic data support observational evidence that shifting energetic homeostasis through exercise may alter the risk of developing breast cancer. Additional adequately powered studies are needed to confirm and expand upon our findings that changes in body composition are associated with changes in BPE. Cancer Prev Res; 9(7); 581-8. ©2016 AACR.

Hepatocellular carcinoma and lifestyles

The majority of hepatocellular carcinoma occurs over pre-existing chronic liver diseases that share cirrhosis as an endpoint. In the last decade, a strong association between lifestyle and hepatocellular carcinoma has become evident. Abundance of energy-rich food and sedentary lifestyles have caused metabolic conditions such as obesity and diabetes mellitus to become global epidemics. Obesity and diabetes mellitus are both tightly linked to non-alcoholic fatty liver disease and also increase hepatocellular carcinoma risk independent of cirrhosis. Emerging data suggest that physical activity not only counteracts obesity, diabetes mellitus and non-alcoholic fatty liver disease, but also reduces cancer risk. Physical activity exerts significant anticancer effects in the absence of metabolic disorders. Here, we present a systematic review on lifestyles and hepatocellular carcinoma.

Lifestyle Risk Factors Among People Who Have Had Cancer Genetic Testing

Hereditary cancer genetic counseling often focuses on medically intensive risk-reduction strategies, like imaging and risk-reducing surgeries. Lifestyle factors also influence cancer risk, but health behavior counseling is not common in genetic counseling. Information about typical lifestyle risk factors among patients seeking hereditary cancer risk is sparse. The current study describes cancer risk-relevant lifestyle factors for people who have had cancer genetic testing. Data came from the Health Information National Trends Survey (HINTS 4) collected in 2013. Analytic variables represented American Cancer Society nutrition and physical activity guidelines. Lifestyle factors were assessed for people who had undergone testing for BRCA1, BRCA2, or Lynch Syndrome genes. Among 3016 HINTS respondents, 135 had cancer genetic testing. Of these, 58 % were overweight or obese. Eighteen percent reported no moderate-intensity physical activity. Average sedentary screen-time was 3.4 h (SE = 0.472) daily. Sixty-three percent drank non-diet soda, and 23 % of these people drank soda every day. Between 18 and 36 % consumed less than 2 ½ cups fruits/vegetables daily. Twenty-four percent were current smokers. Lifestyle risk factors were not different between people who had genetic testing and those who had not. In conclusion, most people who had genetic testing for cancer susceptibility have at least one modifiable risk factor. Genetic counselors have opportunities to impact a counselee's cancer risk not only through risk-tailored medical procedures, but also through lifestyle modification recommendations. Results of the current study may foster a broader discussion of genetic counselors' roles in healthy lifestyle education.

Inverse birth cohort effects in ovarian cancer: Increasing risk in BRCA1/2 mutation carriers and decreasing risk in the general population

OBJECTIVE

BRCA1/2 carriers are at increased risk of ovarian cancer, and some reports suggest an increasing risk in more recent birth cohorts. In contrast, decreasing incidences have been observed in the general population. The aim was to assess the birth cohort effect on ovarian cancer risk in BRCA1/2 carriers relative to their background general population.

METHODS

Data on ovarian cancer incidence was collected for a cohort of 1050 BRCA1/2 mutation carriers ascertained by our regional clinic and retrieved from the general Dutch population cancer registry. Birth cohorts were categorized as pre-1935, 1935-1953, post-1953. Birth cohort effects on the ovarian cancer risk were estimated using hazard ratios (HRs) in BRCA1/2 carriers and Poisson rate ratios in the general population. Standardized incidence ratios (SIRs) were calculated to compare populations. HRs were adjusted for mutation position and family history.

RESULTS

Compared to the pre-1935 cohort, BRCA1 carriers in the 1935-1953 and post-1953 cohorts had an increased ovarian cancer risk of HRadjusted 1.54 (95% CI 1.11-2.14) and 2.40 (95% CI 1.56-3.69), respectively. BRCA2 carriers in the 1935-1953 cohort had an HRadjusted of 3.01 (95% CI 1.47-6.13). The SIRs for the 1935-1953 and post-1953 cohorts were 1.7 and 2.7, respectively, for the BRCA1 carriers and 1.6 times and 2.4 times, respectively, for BRCA2 carriers.

CONCLUSIONS

Mutation carriers, particularly BRCA1 carriers, born in the most recent cohorts, have the highest additional ovarian cancer risk as compared to the general population.

Correlation of Physical Activities and Breast Cancer Characteristics: A Prospective Analysis with Special Focus on Triple Negative Breast Cancer

OBJECTIVE

Several studies have demonstrated that daily physical activity (PA) prevents the development of breast cancer. Our objective was to examine the relationship between PA and clinical and biological tumor characteristics in breast cancer patients in order to determine the impact of energy expenditure (EE) on tumor prognosis.

METHODS

We pooled data from two prospective studies, including a total of 121 breast cancer patients. The measure of PA was done using the self-completion Population Physical Activity Questionnaire, which was answered by each patient.

RESULTS

Ten patients harbored triple negative (TN) tumors. The mean body mass index (BMI) in the general population and in patients with TN tumors was 24.3 and 25.6, respectively. The mean daily EE (DEE) was 10,266 kJ×24 h(-1) in the general population and 11,212 kJ×24 h(-1) in patients with TN tumors. In the whole population, there was an inverse statistical correlation between BMI and DEE, rest, low PA, and high PA (p=0.0002, p=0.003, p<0001, and p=0.03, respectively). There was a positive correlation between negative estrogen receptor status and intensive PA (p=0.041) and DEE (p=0.007). For TN tumors, there was no significant correlation between BMI and categories of EE.

CONCLUSIONS

Lifestyle (weight regulation, PA) should be adapted and personalized according to biological, clinical, and epidemiological characteristics of the tumors.

Breast cancer risk after salpingo-oophorectomy in healthy BRCA1/2 mutation carriers: revisiting the evidence for risk reduction

BACKGROUND

Previous studies have reported a breast cancer (BC) risk reduction of approximately 50% after risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 mutation carriers, but may have been subject to several types of bias. The purpose of this nationwide cohort study was to assess potential bias in the estimated BC risk reduction after RRSO.

METHODS

We selected BRCA1/2 mutation carriers from an ongoing nationwide cohort study on Hereditary Breast and Ovarian Cancer in the Netherlands (HEBON). First, we replicated the analytical methods as previously applied in four major studies on BC risk after RRSO. Cox proportional hazards models were used to calculate hazard ratios and conditional logistic regression to calculate odds ratios. Secondly, we analyzed the data in a revised design in order to further minimize bias using an extended Cox model with RRSO as a time-dependent variable to calculate the hazard ratio. The most important differences between our approach and those of previous studies were the requirement of no history of cancer at the date of DNA diagnosis and the inclusion of person-time preceding RRSO.

RESULTS

Applying the four previously described analytical methods and the data of 551 to 934 BRCA1/2 mutation carriers with a median follow-up of 2.7 to 4.6 years, the odds ratio was 0.61 (95% confidence interval [CI] = 0.35 to 1.08), and the hazard ratios were 0.36 (95% CI = 0.25 to 0.53), 0.62 (95% CI = 0.39 to 0.99), and 0.49 (95% CI = 0.33 to 0.71), being similar to earlier findings. For the revised analysis, we included 822 BRCA1/2 mutation carriers. After a median follow-up period of 3.2 years, we obtained a hazard ratio of 1.09 (95% CI = 0.67 to 1.77).

CONCLUSION

In previous studies, BC risk reduction after RRSO in BRCA1/2 mutation carriers may have been overestimated because of bias. Using a design that maximally eliminated bias, we found no evidence for a protective effect.

A randomized controlled trial of diet and physical activity in BRCA mutation carriers

High serum levels of insulin-like growth factor I (IGF-I) are associated with an increased risk of sporadic breast cancer (BC). Furthermore, insulin and markers of insulin resistance, such as abdominal obesity, high blood glucose, high serum testosterone and metabolic syndrome, may affect both BC incidence and prognosis. We hypothesized that all these factors might be relevant also for hereditary BC, due to a deleterious mutation of BRCA genes. Epidemiological observation suggested that weight, energy intake (usually associated with higher bio-availability of growth factors) and physical activity may be relevant in BRCA mutation carriers. Mechanistic studies hypothesized a functional interaction between BRCA genes and the IGF-I system. We have provided some evidence that high serum levels of IGF-I are associated with a significantly increased penetrance. We are recruiting a larger cohort of BRCA mutation carriers in order to test potential modulators of penetrance and prognosis. Within this cohort, we have planned a randomized controlled trial to test whether moderate calorie and protein restriction, together with physical activity, decrease IGF-I. Eligible study subjects are women with or without BC, aged 18-70, with a proven deleterious BRCA mutation, and without metastases. All the women will receive recommendations for the dietary prevention of cancer. The women will be then randomized into an active life-style intervention group and into a control group that will receive only the baseline recommendations. We expect to significantly reduce IGF-I in the intervention group. This trial and the subsequent cohort follow-up might open up primary prevention options for genetic BC.

The role of body size and physical activity on the risk of breast cancer in BRCA mutation carriers

Women who inherit a BRCA mutation face a high lifetime risk of developing breast cancer. Given the high penetrance of these mutations, prevention is of extreme importance. Here, we review the literature regarding the role of body size and of physical activity in the context of BRCA-associated breast cancer. There is some evidence to support a protective role of a healthy body size and of regular physical activity among mutation carriers, particularly during adolescence or early adulthood. Factors which increase the physiologic expression of the normal copy of the BRCA1 or BRCA2 gene and thereby normalize protein levels, contribute to stem cell homeostasis, and/or affect hormone levels, might mitigate the effects of an inherited BRCA mutation. Preliminary evidence from one in vivo study and from one epidemiologic report suggests that an increase in BRCA1 mRNA expression occurs with increasing levels of physical activity. The prospect of changing lifestyle for the purpose of preventing breast cancer in high-risk women, complemented by mechanistic evidence, warrants evaluation in large-scale prospective studies.

Variation in mutation spectrum partly explains regional differences in the breast cancer risk of female BRCA mutation carriers in the Netherlands

BACKGROUND

We aimed to quantify previously observed relatively high cancer risks in BRCA2 mutation carriers (BRCA2 carriers) older than 60 in the Northern Netherlands, and to analyze whether these could be explained by mutation spectrum or population background risk.

METHODS

This consecutive cohort study included all known pathogenic BRCA1/2 carriers in the Northern Netherlands (N = 1,050). Carrier and general reference populations were: BRCA1/2 carriers in the rest of the Netherlands (N = 2,013) and the general population in both regions. Regional differences were assessed with HRs and ORs. HRs were adjusted for birth year and mutation spectrum.

RESULTS

All BRCA1 carriers and BRCA2 carriers younger than 60 had a significantly lower breast cancer risk in the Northern Netherlands; HRs were 0.66 and 0.64, respectively. Above age 60, the breast cancer risk in BRCA2 carriers in the Northern Netherlands was higher than in the rest of the Netherlands [HR, 3.99; 95% confidence interval (CI), 1.11-14.35]. Adjustment for mutational spectrum changed the HRs for BRCA1, BRCA2 <60, and BRCA2 ≥60 years by -3%, +32%, and +11% to 0.75, 0.50, and 2.61, respectively. There was no difference in background breast cancer incidence between the two regions (OR, 1.03; 95% CI, 0.97-1.09).

CONCLUSIONS

Differences in mutation spectrum only partly explain the regional differences in breast cancer risk in BRCA2 carriers, and for an even smaller part in BRCA1 carriers.

IMPACT

The increased risk in BRCA2 carriers older than 60 may warrant extension of intensive breast screening beyond age 60.

Relevance and efficacy of breast cancer screening in BRCA1 and BRCA2 mutation carriers above 60 years: a national cohort study

Annual MRI and mammography is recommended for BRCA1/2 mutation carriers to reduce breast cancer mortality. Less intensive screening is advised ≥60 years, although effectiveness is unknown. We identified BRCA1/2 mutation carriers without bilateral mastectomy before age 60 to determine for whom screening ≥60 is relevant, in the Rotterdam Family Cancer Clinic and HEBON: a nationwide prospective cohort study. Furthermore, we compared tumour stage at breast cancer diagnosis between different screening strategies in BRCA1/2 mutation carriers ≥60. Tumours >2 cm, positive lymph nodes, or distant metastases at detection were defined as "unfavourable." Of 548 BRCA1/2 mutation carriers ≥60 years in 2012, 395 (72%) did not have bilateral mastectomy before the age of 60. Of these 395, 224 (57%) had a history of breast or other invasive carcinoma. In 136 BRCA1/2 mutation carriers, we compared 148 breast cancers (including interval cancers) detected ≥60, of which 84 (57%) were first breast cancers. With biennial mammography 53% (30/57) of carcinomas were detected in unfavourable stage, compared to 21% (12/56) with annual mammography (adjusted odds ratio: 4·07, 95% confidence interval [1.79-9.28], p = 0.001). With biennial screening 40% of breast cancers were interval cancers, compared to 20% with annual screening (p = 0.016). Results remained significant for BRCA1 and BRCA2 mutation carriers, and first breast cancers separately. Over 70% of 60-year old BRCA1/2 mutation carriers remain at risk for breast cancer, of which half has prior cancers. When life expectancy is good, continuation of annual breast cancer screening of BRCA1/2 mutation carriers ≥60 is worthwhile.