Effects of exercise on sleep problems in breast cancer patients receiving radiotherapy: a randomized clinical trial

Purpose

Sleep problems frequently affect breast cancer patients during and after treatment and reduce their quality of life. Treatment strategies are mostly unknown. Thus, we assessed within a randomized controlled trial whether a 12-week exercise program starting with the radiotherapy influences sleep trajectories.

Methods

Sleep quality and problems were assessed via self-report in 160 breast cancer patients before, during, and 2, 6, and 12 months after participation in a trial investigating resistance exercise versus a relaxation control group concomitant with radiotherapy. As additional comparison group, 25 age-matched healthy women exercised and followed identical study procedures. Ordinal logistic regression analyses were used.

Results

The exercise intervention significantly decreased sleep problems compared to the relaxation control group (scale: 0–100, with between-group mean differences of ?10.2 (p = 0.03) from baseline to the end of radiotherapy and ?10.9 (p = 0.005) to the end of the intervention), with sleep problems decreasing in the exercise group and increasing in the control group. At 12 months, differences were still observed but statistically non-significant (mean difference = ?5.9, p = 0.20). Further adjustment for potential confounders did not change the results. Several determinants of sleep problems at baseline were identified, e.g., previous chemotherapy and higher body mass index.

Conclusions

Our randomized exercise intervention trial confirmed results from earlier but mostly smaller studies that radiotherapy aggravates sleep problems in breast cancer patients and that exercise can ameliorate these effects. Considering that sleep quality can be a major predictor of quality of life, our findings are of substantial importance to many breast cancer patients.

     

The risk of cardiovascular disease following breast cancer by Framingham risk score

Objectives

This study evaluates the risk of cardiovascular disease (CVD) following breast cancer, accounting for baseline CVD risk.

Methods

Within the EPIC-NL (Dutch part of the European Prospective Investigation into Nutrition and Cancer) cohort, 1103 women were diagnosed with breast cancer. For every breast cancer patient, 3–4 women without breast cancer (n = 4328) were selected matched for age, year, and time since cohort enrollment. Based on CVD risk factors at cohort enrollment, 10-year risk of CVD was calculated and categorized: low (< 10%), intermediate (10–20%), high (> 20%). Cox proportional hazard models assessed the risk of CVD events (hospitalization or mortality) and CVD mortality of women with versus without breast cancer, adjusted for baseline CVD risk.

Results

After median follow-up of 5 and 6 years, 92 (8.3%) and 325 (7.5%) CVD events occurred in women with and without breast cancer, respectively. In the low CVD risk group, women with breast cancer had 1.44 (95% CI 1.00–2.06) times higher risk of CVD events than women without breast cancer. In the intermediate and high CVD risk categories, risk of CVD events was similar in women with and without breast cancer. Overall, women with breast cancer had 1.77 (95% CI 1.10–2.86) times higher risk of CVD mortality than women without breast cancer.

Conclusions

Among women with low CVD risk, women with breast cancer have a higher risk of CVD event than women without breast cancer. Overall, women with breast cancer have a higher risk of CVD mortality than women without breast cancer.

     

Contribution of clinical and socioeconomic factors to differences in breast cancer subtype and mortality between Hispanic and non-Hispanic white women

Purpose

To assess tumor subtype distribution and the relative contribution of clinical and sociodemographic factors on breast cancer survival between Hispanic and non-Hispanic whites (NHWs).

Methods

We analyzed data from the California Cancer Registry, which included 29,626 Hispanic and 99,862 NHW female invasive breast cancer cases diagnosed from 2004 to 2014. Logistic regression was used to assess ethnic differences in tumor subtype, and Cox proportional hazard modeling to assess differences in breast cancer survival.

Results

Hispanics compared to NHWs had higher odds of having triple-negative (OR = 1.29; 95% CI 1.23–1.35) and HER2-overexpressing tumors (OR = 1.19; 95% CI 1.14–1.25 [HR?] and OR = 1.39; 95% CI 1.31–1.48 [HR+]). In adjusted models, Hispanic women had a higher risk of breast cancer mortality than NHW women (mortality rate ratio [MRR] = 1.24; 95% CI 1.19–1.28). Clinical factors accounted for most of the mortality difference (MRR = 1.05; 95% CI 1.01–1.09); however, neighborhood socioeconomic status (SES) and health insurance together accounted for all of the mortality difference (MRR = 1.01; 95% CI 0.97–1.05).

Conclusions

Addressing SES disparities, including increasing access to health care, may be critical to overcoming poorer breast cancer outcomes in Hispanics.

     

Pre-diagnostic aspirin use and mortality after breast cancer

Background

Whether aspirin or other nonsteroidal anti-inflammation drug (NSAID) use is associated with mortality following breast cancer remains unclear. Consideration of use patterns and interaction with obesity may help to clarify the inconsistent results.

Methods

Pre-diagnosis NSAID use, weight, and height were assessed?~?3 months after diagnosis through in-person interviews with a population-based cohort of 1,442 women with first primary breast cancer. Vital status was determined through the national death index after ~?18 years of follow-up (N?=?237/597 breast cancer-specific/all-cause deaths). We used Cox proportional hazards regression to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Multiplicative interaction by body mass index (BMI) was evaluated using the likelihood ratio test.

Results

Ever aspirin use was inversely associated with breast cancer-specific mortality (HR 0.87, 95% CI 0.59–1.29), but positively associated with all-cause mortality (HR 1.21, 95% CI 0.99–1.48); the CIs included the null values. The HRs, however, were more pronounced for the highest level of duration, frequency, regularity, and timing for all-cause, but not breast cancer-specific mortality. Interactions with BMI revealed no significant heterogeneity (p_interaction = 0.37 and p_interaction = 0.36, respectively).

Conclusion

Pre-diagnosis aspirin use was not strongly associated with mortality following breast cancer. The all-cause mortality associations, however, were slightly stronger when we considered patterns of use.

     

Pre- and postdiagnostic diet in relation to mortality among breast cancer survivors in the CPS-II Nutrition Cohort

Purpose

Due to the limited evidence on the role of diet and cause-specific mortality among breast cancer survivors, current nutrition guidelines for this population are consistent with those for cancer prevention. We evaluated whether diets consistent with the American Cancer Society recommendations for cancer prevention were associated with risk of death in breast cancer survivors.

Methods

Participants reported information on diet and other factors at baseline in 1992–1993 and twice during follow-up. A nine-point score reflecting concordance with diet recommendations was calculated. Multivariable-adjusted relative risks (RR) and 95 % confidence intervals (CI) for diet score in relation to overall and cause-specific mortality were computed using Cox proportional hazards regression methods.

Results

Among 4,452 women diagnosed with locally and regionally staged breast cancer after baseline and until 2011, 1,204 died during follow-up through 2012 (398 from breast cancer). Prediagnostic diet score was not associated with mortality from any cause. Postdiagnostic diet score was associated with neither breast cancer-specific mortality (RR 1.44, 95 % CI 0.90–2.30 for scores 6–9 vs 0–2) nor cardiovascular disease mortality (RR 0.81, 95 % CI 0.47–1.39), but compared to a score of 0–2, a score of 6–9 was associated with a borderline lower risk of other causes of death (RR 0.78, 95 % CI 0.56–1.07, p _trend = 0.03; per two-point increase in score RR 0.88, 95 % CI 0.79–0.99). Of diet score components, only limiting red and processed meat consumption was associated with statistically significantly lower risk of total, CVD, and other non-breast cancer mortality.

Conclusions

Diets consistent with guidelines for cancer prevention were not associated with breast cancer-specific mortality. However, their association with other causes of mortality underscores the importance of consuming a healthy diet in this population.

     

Active smoking and risk of Luminal and Basal-like breast cancer subtypes in the Carolina Breast Cancer Study

Purpose

Growing evidence suggests an association between active cigarette smoking and increased breast cancer risk. However, the weak magnitude of association and conflicting results have yielded uncertainty and it is unknown whether associations differ by breast cancer subtype.

Methods

Using population-based case–control data from phases I and II of the Carolina Breast Cancer Study, we examined associations between self-reported measures of smoking and risk of Luminal and Basal-like breast cancers. We used logistic regression models to estimate case–control odds ratios (OR) and 95 % confidence intervals (CI).

Results

Ever smoking (current and former) was associated with a weakly increased risk of Luminal breast cancer (OR 1.12, 95 % CI 0.92–1.36) and was not associated with risk of Basal-like breast cancer (OR 0.96, 95 % CI 0.69–1.32). Similarly, smoking duration of more than 20 years was associated with increased risk of Luminal (OR 1.51, 95 % CI 1.19–1.93), but not Basal-like breast cancer (OR 0.90, 95 % CI 0.57–1.43). When stratified by race, elevated odds ratios between smoking and Luminal breast cancer risk were found among black women across multiple exposure measures (ever smoking, duration, and dose); conversely, among white women odds ratios were attenuated or null.

Conclusions

Results from our study demonstrate a positive association between smoking and Luminal breast cancer risk, particularly among black women and women with long smoking histories. Addressing breast cancer heterogeneity in studies of smoking and breast cancer risk may elucidate associations masked in prior studies.

     

Swedish prospective multicenter trial evaluating sentinel lymph node biopsy after neoadjuvant systemic therapy in clinically node-positive breast cancer

Purpose

The clinical significance of nodal micrometastasis is debated. Our primary objective was to determine whether, among women with early-stage breast cancer, regional lymph node micrometastasis is an independent risk factor for mortality. The secondary objective was to identify subgroups of women who have the highest risk of death from early-stage breast cancer with micrometastases.

Methods

206,625 women diagnosed with early-stage breast cancer (IA, IB, and IIA) from 2004 to 2012 were identified in the Surveillance, epidemiology, and end results database. Nodal status was classified as node-negative, isolated-tumor cells, micrometastases, and macrometastases. Women were classified into eight ethnic groups. Logistic regression was performed to estimate the odds ratio of being diagnosed with micrometastases. The Cox proportional hazard model was used to estimate the hazard ratio (HR) of breast cancer-specific death associated with micrometastases for each ethnic group.

Results

The 8-year breast cancer-specific survival was 96.6 % for women with node-negative breast cancers and was 94.6 % for women with micrometastases (adjusted HR 1.49; 95 % CI 1.31–1.69; P < .001). Among women with micrometastases, the 8-year breast cancer-specific survival was 95.1 % for white women and was 90.6 % for black women (HR 1.80; 95 % CI 1.29–2.52; P = .0006).

Conclusion(s)

Nodal micrometastasis is an independent risk factor for breast cancer mortality among women with early-stage breast cancer. Black women are more likely to die from breast cancer with micrometastases than white women.

     

Economic and disease burden of breast cancer associated with suboptimal breastfeeding practices in Mexico

Purpose

Exclusive breastfeeding and longer breastfeeding reduce women’s breast cancer risk but Mexico has one of the lowest breastfeeding rates worldwide. We estimated the lifetime economic and disease burden of breast cancer in Mexico if 95% of parous women breastfeed each child exclusively for 6 months and continue breastfeeding for over a year.

Methods

We used a static microsimulation model with a cost-of-illness approach to simulate a cohort of Mexican women. We estimated breast cancer incidence, premature mortality, disability-adjusted life years (DALYs), medical costs, and income losses due to breast cancer and extrapolated the results to 1.116 million Mexican women of age 15 in 2012. Costs were expressed in 2015 US dollars and discounted at a 3% annual rate.

Results

We estimated that 2,186 premature deaths (95% CI 2,123–2,248), 9,936 breast cancer cases (95% CI 9,651–10,220), 45,109 DALYs (95% CI 43,000–47,217), and $245 million USD (95% CI 234–256) in medical costs and income losses owing to breast cancer could be saved over a cohort’s lifetime. Medical costs account for 80% of the economic burden; income losses and opportunity costs for caregivers account for 15 and 5%, respectively.

Conclusions

In Mexico, the burden of breast cancer due to suboptimal breastfeeding in women is high in terms of morbidity, premature mortality, and the economic costs for the health sector and society.

     

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Implications for cancer survivors

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

     

Diabetes and breast cancer mortality in Black women

Purpose

Breast cancer mortality is higher in Black women than in White women. The prevalence of type 2 diabetes mellitus is also higher, yet data on whether diabetes affects breast cancer mortality in this population are lacking. We investigated the relation of diabetes at the time of breast cancer diagnosis to breast cancer mortality in the Black Women’s Health Study, a prospective cohort study.

Methods

1,621 Black women with invasive breast cancer diagnosed in 1995–2013 were followed by mailed questionnaires and searches of the National Death Index. Multivariable Cox regression analysis was used to compute hazard ratios (HRs) for diabetes in relation to breast cancer mortality and all-cause mortality, with adjustment for age, stage, treatment modality, estrogen receptor (ER) status, and body mass index.

Results

There were 368 deaths during follow-up, of which 273 were due to breast cancer. Breast cancer mortality was significantly increased in women who had been diagnosed with diabetes at least 5 years before breast cancer occurrence, HR 1.86 (95% CI 1.20–2.89), with elevations observed for both ER+ and ER? breast cancer. All-cause mortality was also higher in diabetics, with HRs of 1.54 (95% CI 1.12–2.07) overall and 2.26 (95% CI 1.62–3.15) for ≥5-year duration of diabetes relative to non-diabetics.

Conclusions

Our results present the first solid evidence of a positive association of type 2 diabetes with breast cancer mortality in Black women. Given the higher prevalence and earlier onset of type 2 diabetes in Black women, it is likely that diabetes contributes to racial disparities in breast cancer mortality.

     

Breast self-exam and patient interval associate with advanced breast cancer and treatment delay in Mexican women

Purpose

The objective of this study was to compare treatment intervals in breast cancer patients according to the detection method (breast self-exam vs screening).

Patients and methods

We conducted a retrospective analysis including 291 breast cancer patients at a Mexican tertiary referral hospital.

Results

Breast cancer detection method was mostly breast self-exam (60%). The median patient interval was 60.5 days, and was associated with marital status and socioeconomic level. Differences between the two groups were statistically significant for global interval, p = 0.002; however, health system interval was not statistically different.

Conclusion

In our country, breast cancer screening is opportunistic, with several weaknesses within its management and quality systems. Our study showed that even in specialized health care centers, breast cancer is detected by self-exam in up to 2/3 of patients, which can explain the advanced stages at diagnosis in our country. In developing countries, the immediate health care access for breast cancer patients should be prioritized as an initial step to reduce the global treatment initiation interval in order to reduce mortality.

     

Changes in importance of work and vocational satisfaction during the 2 years after breast cancer surgery and factors associated with this

Purpose

The purpose of this study is to investigate how women, during the 2 years following breast cancer surgery, rate importance of work and vocational satisfaction, and baseline factors associated with rating over time.

Methods

A prospective cohort study of 692 women aged 20–63 included about 4 weeks after a first breast cancer surgery. Register data on treatment and data from six repeated questionnaires during a 2-year follow-up (at baseline, 4, 8, 12, 18, 24 months) were used in two-way mixed repeated analysis of variance and mixed repeated measures analysis of covariance.

Results

The women rated importance of work (m?=?3.74; sd 0.88) (maximum 5) and vocational satisfaction (m?=?4.30; sd 1.38) (maximum 6) high during the 2 years. Women with planned chemotherapy rated lower vocational satisfaction and especially so at 4 months after inclusion (F 1, 498?=?8.20; p?=?0.004). Higher age, better physical, and mental/social work ability at baseline influenced rating of vocational satisfaction. Supportive colleagues was an important covariate that significantly affected ratings of importance of work as well as vocational satisfaction, i.e., women with better support rated on average higher on these outcomes. The effect of chemotherapy disappeared after including the abovementioned baseline covariates.

Conclusions

Women diagnosed with breast cancer in the following 2 years rate importance of work and vocational satisfaction high, which are associated to lower work ability and social support.

Implications for cancer survivors

Work is a very important aspect in life also after a cancer diagnosis, which has to be acknowledged when discussing treatment and rehabilitation plans with women with breast cancer. Furthermore, workplace support needs to be assessed as this is an influential factor.

     

Brustkrebsfrüherkennung

Background

The benefits and disadvantages of breast cancer screening programs are the subject of current discussion.

Aim

The aim of this article is to summarize the current literature on target groups, methods, benefits, and side effects of early detection programs for breast cancer.

Material and Methods

This article is based on a selective PubMed search using key words, publications of the Robert Koch Institute, the reports of the German organizations the “Mammography Cooperative,” the “Federal Joint Committee,” and the “Institute for Quality and Efficiency in Healthcare.”

Results

Target groups for an early detection program for breast cancer are women in the age group 50 to 69 years (German Mammography Screening), women with hereditary breast cancer, and women who received radiotherapy of the chest wall during childhood and adolescence to treat malignancies. According to international randomized controlled trials, with mammography every 2 years and a participation rate of 65–85?%, women in the age group 50–69 show a breast cancer mortality reduction of 20?%. MRI-based early detection programs in women with hereditary breast cancer lead to the discovery of tumors at lower stages and significantly improved metastasis-free survival. The most significant side effect of the mammography-based screening program is over-diagnosis, the estimation of which varies greatly in the literature. The vast majority of international recommendations are in favor of mammography screening programs.

Discussion

In the future a more risk-adapted screening program for the general population would be desirable, to improve the benefit–risk balance.

     

Frailty and long-term mortality of older breast cancer patients: CALGB 369901 (Alliance)

Purpose

Breast cancer patients aged 65+ (“older”) vary in frailty status. We tested whether a deficits accumulation frailty index predicted long-term mortality.

Methods

Older patients (n = 1280) with non-metastatic, invasive breast cancer were recruited from 78 Alliance sites from 2004 to 2011, with follow-up to 2015. Frailty categories (robust, pre-frail, and frail) were based on 35 baseline illness and function items. Cox proportional hazards and competing risk models were used to calculate all-cause and breast cancer-specific mortality for up to 7 years, respectively. Potential covariates included demographic, psychosocial, and clinical factors, diagnosis year, and care setting.

Results

Patients were 65–91 years old. Most (76.6%) were robust; 18.3% were pre-frail, and 5.1% frail. Robust patients tended to receive more chemotherapy ± hormonal therapy (vs. hormonal) than pre-frail or frail patients (45% vs. 37 and 36%, p = 0.06), and had the highest adherence to hormonal therapy. The adjusted hazard ratios for all-cause mortality (n = 209 deaths) were 1.7 (95% CI 1.2–2.4) and 2.4 (95% CI 1.5–4.0) for pre-frail and frail versus robust women, respectively, with an absolute mortality difference of 23.5%. The adjusted hazard of breast cancer death (n?99) was 3.1 (95% CI 1.6–5.8) times higher for frail versus robust patients (absolute difference of 14%). Treatment differences did not account for the relationships between frailty and mortality.

Conclusions

Most older breast cancer patients are robust and could consider chemotherapy where otherwise indicated. Patients who are frail or pre-frail have elevated long-term all-cause and breast cancer mortality. Frailty indices could be useful for treatment decision-making and care planning with older patients.

     

Correlation of FANCM expression with clinical factors in luminal B breast cancer

Background

The genotype of Fanconi Anemia complementation group M (FANCM) was previously found to be associated with breast cancer risk in several populations. Here, we studied the expression of FANCM and its correlation with clinical characteristics in Chinese patients with breast cancer.

Methods

We performed an immunohistochemical study of FANCM protein in clinical breast cancer tissues from 310 patients along with 44 adjacent tissues.

Results

FANCM protein level is lower in triple-negative breast cancer tissues than in other subtypes (P = 0.008). In addition, high FANCM expression correlated with pathology type IDC (P = 0.040), estrogen receptor positive (P < 0.001), progesterone receptor positive (P = 0.001), and low Ki-67 status (P = 0.003). Multivariate analysis revealed that FANCM status was an independent prognostic factor for overall survival (P = 0.017) in luminal B breast cancer.

Conclusions

FANCM levels are significantly associated with different subtypes of human breast cancer. Specifically, FANCM could play a role in the progression of luminal B breast cancer.

     

Sedentary time and postmenopausal breast cancer incidence

Purpose

The objective of this study was to evaluate the prospective association between sedentary time and postmenopausal breast cancer incidence, and whether associations differ by race/ethnicity, physical activity levels, and body measurements.

Methods

The Women’s Health Initiative Observational Study is a prospective cohort among women ages 50–79 years at baseline (1994–1998) (analytic cohort?=?70,233). Baseline questionnaire data were used to estimate time spent sitting and total sedentary time. Associations between time spent sitting and invasive breast cancer incidence overall (n?=?4,115 cases through September 2015), and by hormone receptor subtypes, were investigated using Cox proportional hazards regression. Analyses were replicated stratified by race/ethnicity, body measurements, and physical activity.

Results

Among women in this study, 34.5% reported?≤?5 h/day sitting, 40.9% reported 6–9 h/day and 24.7% reported?≥?10 h/day. Time spent sitting (≥?10 vs. ≤5 h/day adjusted HR?=?1.00, 95% CI 0.92–1.09) was not associated with breast cancer incidence, regardless of hormone receptor subtype. Associations did not differ by race/ethnicity, physical activity, or body measurements.

Conclusions

Results from this study do not support an association between sedentary time and breast cancer incidence.

     

Sleep disruption,chronotype, shift work,and prostate cancer risk and mortality: a 30-year prospective cohort study of Finnish twins

Purpose

Sleep disruption and shift work have been associated with cancer risk, but epidemiologic evidence for prostate cancer remains limited. We aimed to prospectively investigate the association between midlife sleep- and circadian-related parameters and later prostate cancer risk and mortality in a population-based cohort of Finnish twins.

Methods

Data were drawn from the Older Finnish Twin Cohort and included 11,370 twins followed from 1981 to 2012. Over the study period, 602 incident cases of prostate cancer and 110 deaths from prostate cancer occurred. Cox regression was used to evaluate associations between midlife sleep duration, sleep quality, chronotype, and shift work with prostate cancer risk and prostate cancer-specific mortality. Within-pair co-twin analyses were employed to account for potential familial confounding.

Results

Compared to “definite morning” types, “somewhat evening” types had a significantly increased risk of prostate cancer (HR 1.3; 95 % CI 1.1, 1.6). Chronotype significantly modified the relationship between shift work and prostate cancer risk (p-interaction <0.001). We found no significant association between sleep duration, sleep quality, or shift work and prostate cancer risk in the overall analyses and no significant association between any sleep- or circadian-related parameter and risk in co-twin analyses. Neither sleep- nor circadian-related parameters were significantly associated with prostate cancer-specific mortality.

Conclusion

The association between sleep disruption, chronotype, and shift work with prostate cancer risk and mortality has never before been studied in a prospective study of male twins. Our findings suggest that chronotype may be associated with prostate cancer risk and modify the association between shift work and prostate cancer risk. Future studies of circadian disruption and prostate cancer should account for this individual-level characteristic.

     

3D conformal radiotherapy is not associated with the long-term cardiac mortality in breast cancer patients: a retrospective cohort study in Germany (PASSOS-Heart Study)

Purpose

In breast cancer patients treated in the 1970s and 1980s, radiation therapy (RT) for left-sided tumors has been associated with an elevated risk of cardiac mortality. In recent years, improved RT techniques have reduced radiation exposure of the heart and major coronary vessels, but some exposure remains unavoidable. In a retrospective cohort study, we investigated the long-term cardiac mortality risk of breast cancer survivors treated with modern RT in Germany.

Methods

A total of 11,982 women were included who were treated for breast cancer between 1998 and 2008. A systematic mortality follow-up was conducted until December 2012. The effect of breast cancer laterality on cardiac mortality and on overall mortality was investigated as a surrogate measure of exposure. Using Cox regression, we analyzed survival time as the primary outcome measure, taking potential confounding factors into account.

Results

We found no evidence for an effect of tumor laterality on mortality in irradiated patients (N = 9058). For cardiac mortality, the hazard ratio was 0.94 (95% CI 0.64–1.38) for left-sided versus right-sided tumors. For all causes of death, the hazard ratio was 0.95 (95% CI 0.85–1.05). A diagnosis of cardiac illness prior to breast cancer treatment increased both cardiac mortality risk and overall mortality risk.

Conclusions

Contemporary RT seems not to be associated with an increased risk of cardiac mortality or overall mortality for left-sided breast cancer relative to right-sided RT. However, an extended follow-up period and exact dosimetry might be necessary to confirm this observation.

     

Obesity and mortality after locoregional breast cancer diagnosis

Purpose

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

Methods

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

Results

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

Conclusions

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