The After Breast Cancer Pooling Project: rationale, methodology, and breast cancer survivor characteristics

Patterns of Physical Activity and the Role of Obesity and Comorbidities Among Long-term African American Breast Cancer Survivors

PURPOSE

Physical activity (PA) has many health benefits for cancer survivors, but little research has examined patterns and correlates in African American women, who have a higher burden of comorbidities and obesity. We examined PA types and patterns overall and by obesity and comorbidities among long-term (> 5 years) breast cancer survivors.

METHODS

This cross-sectional study included 323 women who were previous participants of a case-only study in three southeastern states. Women completed a survivorship-focused questionnaire using validated measures to collect data on cancer treatment, PA (recreational, household, transportation) and other lifestyle factors, and comorbidities. Logistic regression models estimated adjusted ORs and 95% CIs for total PA (all three types, categorized as tertiles) and meeting PA guidelines (> 150 min/week of exercise).

RESULTS

The mean age of women was 59.1 years (range 27.9-79.5). The most frequent PA types (≥ 1/month) included routine household cleaning (92.9%), shopping (94.7%), walking slowly (42.1%), and walking briskly (40.6%). Less than 40% met PA guidelines. Women with more total comorbidities, arthritis, and obesity had lower levels of total PA (minutes/week) and/or recreational PA. In adjusted models, BMI ≥ 35 kg/m2 was associated with reduced odds of total PA (OR = 0.33, 95% CI 0.12-0.88, highest tertile). Arthritis was associated with reduced odds of meeting PA guidelines (OR = 0.61, 95% CI 36-1.05).

CONCLUSIONS

Close to 60% of African American breast cancer survivors did not meet PA guidelines based on recreational PA participation. Household PA was an important source of PA. Comorbidities and obesity were associated with both reduced total PA and not meeting PA guidelines.

Evidence-based nutrition guidelines for cancer survivors in Europe: a call for action

BACKGROUND/OBJECTIVES

The aims of this study were to (1) document currently available guidelines aimed at healthcare professionals and including some information on the nutritional management of cancer survivors in Europe; (2) assess the quality of these guidelines and (3) document the nutrition recommendations promoted.

METHODS

Four search strategies were implemented in 2018 and updated in 2021 to locate guidelines. Papers were included if they described a European guideline or recommendation for cancer survivors that contained nutrition guidance and there were no language restrictions. Two reviewers independently assessed guideline quality using the AGREE II instrument and nutrition content was extracted and summarised.

RESULTS

Five guidelines (of 593 documents located through the searches) met the inclusion criteria. The ESPEN guidelines were deemed to have the highest methodological quality. Limited information on nutrition was available in these guidelines with the majority of focus being on the promotion of fruit, vegetables and wholegrains and reducing fat, red meat and alcohol. Weight management was mentioned by all five guidelines. There was no detailed information available for cancer survivors or their healthcare team and no practical strategies for the implementation of recommendations.

CONCLUSIONS

There is a need for nutrition guidelines specific for cancer survivors in a European setting. Current guidelines are limited and focus on broad recommendations, while lacking in practical strategies for implementation. There is also a tendency to recommend cancer prevention guidelines be used for cancer survivors rather than developing specific guidance for this group.

Diet Before and After Breast Cancer

The incidence of breast cancer has dramatically increased recently in several Asian countries. This region has experienced rapid economic growth and demographic and environmental changes. Breast cancer rates vary substantially among countries, with a lower incidence in developing countries than that in Western countries. Given the upward trend of breast cancer incidence in Asian countries and the large variation in incidence around the world, dietary changes may contribute to breast cancer development. In particular, nutrients and foods from animal sources have drawn attention as potential causes of breast cancer given that obesity and energy balance appear to be important factors associated with breast cancer risk. However, prospective cohort and intervention studies do not support the hypothesis that diet in middle life influences breast cancer development. However, recent studies have provided better insight into the roles of dietary factors in specific types of breast cancers, such as estrogen receptor-negative (ER-) breast cancer. Some studies suggest that diet in early life may play a substantial role in breast cancer development, but data and evidence remain limited.Although etiologic and epidemiologic studies have long studied modifiable risk factors for breast cancer incidence, much remains to be explored regarding the role of diet after a breast cancer diagnosis. Several epidemiologic studies have explored the factors that improve breast cancer survival rates, including diet, physical activity, and body mass index (BMI). While there is evidence of the effect of BMI on breast cancer mortality, the effects of changing dietary habits after a breast cancer diagnosis on survival or recurrence are less clear. A report of the World Cancer Research Fund stated that evidence was not sufficient to draw firm conclusions about the effect of diet and nutrition on breast cancer prognosis, but it did suggest a link between diet and breast cancer survival.The global burden of breast cancer is increasing and breast cancer is a major and emerging health problem in both developed and developing countries. For example, the five-year survival rate for Korean breast cancer patients has improved from 78.0% in 1993-1995 to 92.7% in 2012-2016. This improvement emphasizes the importance of supportive care, diet, and quality of life for breast cancer survivors. However, we have limited data of non-Western breast cancer survivors. There is a need to examine the role of diet in breast cancer survival in both Western and non-Western regions.

A Comparative Analysis of Breast Cancer Detection and Diagnosis Using Data Visualization and Machine Learning Applications

In the developing world, cancer death is one of the major problems for humankind. Even though there are many ways to prevent it before happening, some cancer types still do not have any treatment. One of the most common cancer types is breast cancer, and early diagnosis is the most important thing in its treatment. Accurate diagnosis is one of the most important processes in breast cancer treatment. In the literature, there are many studies about predicting the type of breast tumors. In this research paper, data about breast cancer tumors from Dr. William H. Walberg of the University of Wisconsin Hospital were used for making predictions on breast tumor types. Data visualization and machine learning techniques including logistic regression, k-nearest neighbors, support vector machine, naïve Bayes, decision tree, random forest, and rotation forest were applied to this dataset. R, Minitab, and Python were chosen to be applied to these machine learning techniques and visualization. The paper aimed to make a comparative analysis using data visualization and machine learning applications for breast cancer detection and diagnosis. Diagnostic performances of applications were comparable for detecting breast cancers. Data visualization and machine learning techniques can provide significant benefits and impact cancer detection in the decision-making process. In this paper, different machine learning and data mining techniques for the detection of breast cancer were proposed. Results obtained with the logistic regression model with all features included showed the highest classification accuracy (98.1%), and the proposed approach revealed the enhancement in accuracy performances. These results indicated the potential to open new opportunities in the detection of breast cancer.

Nutrition and Breast Cancer: A Literature Review on Prevention, Treatment and Recurrence

Breast cancer (BC) is the second most common cancer worldwide and the most commonly occurring malignancy in women. There is growing evidence that lifestyle factors, including diet, body weight and physical activity, may be associated with higher BC risk. However, the effect of dietary factors on BC recurrence and mortality is not clearly understood. Here, we provide an overview of the current evidence obtained from the PubMed databases in the last decade, assessing dietary patterns, as well as the consumption of specific food-stuffs/food-nutrients, in relation to BC incidence, recurrence and survival. Data from the published literature suggest that a healthy dietary pattern characterized by high intake of unrefined cereals, vegetables, fruit, nuts and olive oil, and a moderate/low consumption of saturated fatty acids and red meat, might improve overall survival after diagnosis of BC. BC patients undergoing chemotherapy and/or radiotherapy experience a variety of symptoms that worsen patient quality of life. Studies investigating nutritional interventions during BC treatment have shown that nutritional counselling and supplementation with some dietary constituents, such as EPA and/or DHA, might be useful in limiting drug-induced side effects, as well as in enhancing therapeutic efficacy. Therefore, nutritional intervention in BC patients may be considered an integral part of the multimodal therapeutic approach. However, further research utilizing dietary interventions in large clinical trials is required to definitively establish effective interventions in these patients, to improve long-term survival and quality of life.

Postdiagnosis social networks and breast cancer mortality in the After Breast Cancer Pooling Project

BACKGROUND

Large social networks have been associated with better overall survival, though not consistently with breast cancer (BC)-specific outcomes. This study evaluated associations of postdiagnosis social networks and BC outcomes in a large cohort.

METHODS

Women from the After Breast Cancer Pooling Project (n = 9267) provided data on social networks within approximately 2 years of their diagnosis. A social network index was derived from information about the presence of a spouse/partner, religious ties, community ties, friendship ties, and numbers of living first-degree relatives. Cox models were used to evaluate associations, and a meta-analysis was used to determine whether effect estimates differed by cohort. Stratification by demographic, social, tumor, and treatment factors was performed.

RESULTS

There were 1448 recurrences and 1521 deaths (990 due to BC). Associations were similar in 3 of 4 cohorts. After covariate adjustments, socially isolated women (small networks) had higher risks of recurrence (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.15-1.77), BC-specific mortality (HR, 1.64; 95% CI, 1.33-2.03), and total mortality (HR, 1.69; 95% CI, 1.43-1.99) than socially integrated women; associations were stronger in those with stage I/II cancer. In the fourth cohort, there were no significant associations with BC-specific outcomes. A lack of a spouse/partner (P = .02) and community ties (P = .04) predicted higher BC-specific mortality in older white women but not in other women. However, a lack of relatives (P = .02) and friendship ties (P = .01) predicted higher BC-specific mortality in nonwhite women only.

CONCLUSIONS

In a large pooled cohort, larger social networks were associated with better BC-specific and overall survival. Clinicians should assess social network information as a marker of prognosis because critical supports may differ with sociodemographic factors. Cancer 2017;123:1228-1237. © 2016 American Cancer Society.

Impact of very low physical activity, BMI, and comorbidities on mortality among breast cancer survivors

The purpose of this study was to examine post-diagnosis BMI, very low physical activity, and comorbidities, as predictors of breast cancer-specific and all-cause mortality. Data from three female US breast cancer survivor cohorts were harmonized in the After Breast Cancer Pooling Project (n = 9513). Delayed entry Cox proportional hazards models were used to examine the impact of three post-diagnosis lifestyle factors: body mass index (BMI), select comorbidities (diabetes only, hypertension only, or both), and very low physical activity (defined as physical activity <1.5 MET h/week) in individual models and together in multivariate models for breast cancer and all-cause mortality. For breast cancer mortality, the individual lifestyle models demonstrated a significant association with very low physical activity but not with the selected comorbidities or BMI. In the model that included all three lifestyle variables, very low physical activity was associated with a 22 % increased risk of breast cancer mortality (HR 1.22, 95 % CI 1.05, 1.42). For all-cause mortality, the three individual models demonstrated significant associations for all three lifestyle predictors. In the combined model, the strength and significance of the association of comorbidities (both hypertension and diabetes versus neither: HR 2.16, 95 % CI 1.79, 2.60) and very low physical activity (HR 1.35, 95 % CI 1.22, 1.51) remained unchanged, but the association with obesity was completely attenuated. These data indicate that after active treatment, very low physical activity, consistent with a sedentary lifestyle (and comorbidities for all-cause mortality), may account for the increased risk of mortality, with higher BMI, that is seen in other studies.

Cigarette Smoking Before and After Breast Cancer Diagnosis: Mortality From Breast Cancer and Smoking-Related Diseases

PURPOSE

Cigarette smoking increases overall mortality, but it is not established whether smoking is associated with breast cancer prognosis.

METHODS

We evaluated the association between smoking status before and after breast cancer diagnosis and mortality in the Collaborative Breast Cancer and Women's Longevity Study, a population-based prospective observational study conducted in Wisconsin, New Hampshire, and Massachusetts. Participants included 20,691 women, ages 20 to 79 years, diagnosed with incident localized or regional invasive breast cancer between 1988 and 2008; a subset of 4,562 of these women were recontacted a median of 6 years after diagnosis. Hazard ratios (HRs) with 95% CIs were calculated according to smoking status for death as a result of breast cancer; cancers of the lung, pharynx, or intrathoracic organs; other cancer; respiratory disease; and cardiovascular disease.

RESULTS

During a median of 12 years, 6,778 women died, including 2,894 who died as a result of breast cancer. Active smokers 1 year before breast cancer diagnosis were more likely than never smokers to die of breast cancer (HR, 1.25; 95% CI, 1.13 to 1.37), respiratory cancer (HR, 14.48; 95% CI, 9.89 to 21.21), other respiratory disease (HR, 6.02; 95% CI, 4.55 to 7.97), and cardiovascular disease (HR, 2.08; 95% CI, 1.80 to 2.41). The 10% of women who continued to smoke after diagnosis were more likely than never smokers to die of breast cancer (HR, 1.72; 95% CI, 1.13 to 2.60). When compared with women who continued to smoke after diagnosis, those who quit smoking after diagnosis had lower mortality from breast cancer (HR, 0.67; 95% CI, 0.38 to 1.19) and respiratory cancer (HR, 0.39; 95% CI, 0.16 to 0.95).

CONCLUSION

Smoking before or after diagnosis was associated with a higher mortality from breast cancer and several other causes.

Post-diagnosis social networks, and lifestyle and treatment factors in the After Breast Cancer Pooling Project

OBJECTIVE

Larger social networks have been associated with better breast cancer survival. To investigate potential mediators, we evaluated associations of social network size and diversity with lifestyle and treatment factors associated with prognosis.

METHODS

We included 9331 women from the After Breast Cancer Pooling Project who provided data on social networks within approximately two years following diagnosis. A social network index was derived from information about the presence of a spouse or intimate partner, religious ties, community participation, friendship ties, and numbers of living relatives. Diversity was assessed as variety of ties, independent of size. We used logistic regression to evaluate associations with outcomes and evaluated whether effect estimates differed using meta-analytic techniques.

RESULTS

Associations were similar across cohorts though analyses of smoking and alcohol included US cohorts only because of low prevalence of these behaviors in the Shanghai cohort. Socially isolated women were more likely to be obese (OR = 1.21, 95% CI:1.03-1.42), have low physical activity (<10 MET-hours/week, OR = 1.55, 95% CI:1.36-1.78), be current smokers (OR = 2.77, 95% CI:2.09-3.68), and have high alcohol intake (≥15 g/d, OR = 1.23, 95% CI:1.00-1.51), compared with socially integrated women. Among node positive cases from three cohorts, socially isolated women were more likely not to receive chemotherapy (OR = 2.10, 95% CI:1.30-3.39); associations differed in a fourth cohort. Other associations (nonsignificant) were consistent with less intensive treatment in socially isolated women. Low social network diversity was independently associated with more adverse lifestyle, but not clinical, factors.

CONCLUSIONS

Small, less diverse social networks measured post-diagnosis were associated with more adverse lifestyle factors and less intensive cancer treatment. Copyright © 2016 John Wiley & Sons, Ltd.

A pooled analysis of post-diagnosis lifestyle factors in association with late estrogen-receptor-positive breast cancer prognosis

Lifestyle factors have been well studied in relation to breast cancer prognosis overall; however, associations of lifestyle and late outcomes (>5 years after diagnosis) have been much less studied, and no studies have focused on estrogen receptor-positive (ER+) breast cancer survivors, who may have high risk of late recurrence and mortality. We utilized a large prospective pooling study to evaluate the associations of lifestyle factors with late recurrence and all-cause mortality among 6,295 5-year ER+ Stage I-III breast cancer survivors. Pooled and harmonized data were available on clinical factors and lifestyle factors (pre- to post-diagnosis weight change, body mass index (BMI) (kg/m(2)), recreational physical activity, alcohol intake and smoking history), measured on average 2.1 years after diagnosis. Updated information for weight only was available. Study heterogeneity was evaluated by the Q-statistic. Multivariable Cox regression models were stratified by study. Adjusting for clinical factors and potential confounders, ≥ 10% weight gain and obesity (BMI, 30-34.99 and ≥ 35) were associated with increased risk of late recurrence (hazard ratios (95% confidence intervals): 1.24 (1.00-1.53), 1.40 (1.05-1.86) and 1.41 (1.02-1.93), respectively). Daily alcohol intake was associated with late recurrence, 1.28 (1.01-1.62). Physical activity was inversely associated with late all-cause mortality (0.81 (0.71-0.93) and 0.71 (0.61-0.82) for 4.9 to <17.4 and ≥ 17.4 metabolic equivalent-hr/week). A U-shaped association was observed for late all-cause mortality and BMI using updated weight (1.42 (1.15-1.74) and 1.40 (1.09-1.81), <21.5 and ≥ 35, respectively). Smoking was associated with increased risk of late outcomes. In this large prospective pooling project, modifiable lifestyle factors were associated with late outcomes among long-term ER+ breast cancer survivors.

Double-Blind Randomized 12-Month Soy Intervention Had No Effects on Breast MRI Fibroglandular Tissue Density or Mammographic Density

Soy supplementation by patients with breast cancer remains controversial. No controlled intervention studies have investigated the effects of soy supplementation on mammographic density in patients with breast cancer. We conducted a double-blind, randomized, placebo-controlled intervention study in previously treated patients with breast cancer (n = 66) and high-risk women (n = 29). We obtained digital mammograms and breast MRI scans at baseline and after 12 months of daily soy (50 mg isoflavones per day; n = 46) or placebo (n = 49) tablet supplementation. The total breast area (MA) and the area of mammographic density (MD) on the mammogram were measured using a validated computer-assisted method, and mammographic density percent (MD% = 100 × MD/MA) was determined. A well-tested computer algorithm was used to quantitatively measure the total breast volume (TBV) and fibroglandular tissue volume (FGV) on the breast MRI, and the FGV percent (FGV% = 100 × FGV/TBV) was calculated. On the basis of plasma soy isoflavone levels, compliance was excellent. Small decreases in MD% measured by the ratios of month 12 to baseline levels were seen in the soy (0.95) and the placebo (0.87) groups; these changes did not differ between the treatments (P = 0.38). Small decreases in FGV% were also found in both the soy (0.90) and the placebo (0.92) groups; these changes also did not differ between the treatments (P = 0.48). Results were comparable in patients with breast cancer and high-risk women. We found no evidence that soy supplementation would decrease mammographic density and that MRI might be more sensitive to changes in density than mammography.

Effect of chemotherapy on dietary glycemic index and load in patients with breast cancer and their relationships to body fat and phase angle

Dietary glycemic index (GI) and glycemic load (GL) are indicators of carbohydrate consumption and widely used in studies evaluating the risk for breast cancer. However, the effect of chemotherapy on these indices has been scarcely studied. The aim of this study was to evaluate dietary levels of GI and GL in women with breast cancer during chemotherapy treatment and their relationships to body fat and phase angle. Twenty-five patients were assessed according to demographic, clinical, anthropometric, and food consumption data. Dietary intake was assessed by 24-h dietary recalls applied on nonconsecutive days. Anthropometric measures and body composition were determined at all study timepoints: prior to the first chemotherapy cycle (T0), immediately after the last chemotherapy cycle (T1), and 2 months after T1 (T2). There was no difference in mean GI and GL among study timepoints. However, a high prevalence of inadequate GI and GL values was noted, independent of study timepoint. GI and GL were associated with phase angle at T1. GI was associated with percentage fat at T0 only. Dietary GI and GL were unchanged during chemotherapy, but were associated with indicators of clinical outcome, such as percentage fat and phase angle.

Lifetime cigarette smoking and breast cancer prognosis in the After Breast Cancer Pooling Project

BACKGROUND

There is controversy on whether former smokers have increased risk for breast cancer recurrence or all-cause mortality, regardless of how much they smoked.

METHODS

Data were from three US cohorts in the After Breast Cancer Pooling Project, with detailed information on smoking among 9975 breast cancer survivors. Smoking was assessed an average of 2 years after diagnosis. Delayed entry Cox proportional hazards models were used to examine the relationships of smoking status, cigarettes per day, years of smoking, and pack years with breast cancer prognosis. Endpoints included breast cancer recurrence (n = 1727), breast cancer mortality (n = 1059), and overall mortality (n = 1803).

RESULTS

Compared with never smokers, former smokers with less than 20 pack-years of exposure had no increased risk of any outcome. However, former smokers with 20 to less than 34.9 pack-years of exposure had a 22% increased risk of breast cancer recurrence (hazard ratio [HR] = 1.22; 95% confidence interval [CI] = 1.01 to 1.48) and a 26% increased risk of all-cause mortality (HR = 1.26; 95% CI = 1.07 to 1.48). For former smokers with 35 or more pack-years of exposure, the probability of recurrence increased by 37% (HR = 1.37; 95% CI = 1.13 to 1.66), breast cancer mortality increased by 54% (HR = 1.54; 95% CI = 1.24 to 1.91), and all-cause mortality increased by 68% (HR = 1.68; 95% CI = 1.44 to 1.96). Current smoking increased the probability of recurrence by 41% (HR = 1.41; 95% CI = 1.16 to 1.71), increased breast cancer mortality by 60% (HR = 1.61; 95% CI = 1.28 to 2.03), and doubled the risk of all-cause mortality (HR = 2.17; 95% CI = 1.85 to 2.54).

CONCLUSIONS

Lifetime cigarette smoking was statistically significantly associated with a poor prognosis among women diagnosed with breast cancer, dose-dependent increased risks of recurrence, and breast cancer and all-cause mortality.

The California Breast Cancer Survivorship Consortium (CBCSC): prognostic factors associated with racial/ethnic differences in breast cancer survival

Racial/ethnic disparities in mortality among US breast cancer patients are well documented. Our knowledge of the contribution of lifestyle factors to disease prognosis is based primarily on non-Latina Whites and is limited for Latina, African American, and Asian American women. To address this knowledge gap, the California Breast Cancer Survivorship Consortium (CBCSC) harmonized and pooled interview information (e.g., demographics, family history of breast cancer, parity, smoking, alcohol consumption) from six California-based breast cancer studies and assembled corresponding cancer registry data (clinical characteristics, mortality), resulting in 12,210 patients (6,501 non-Latina Whites, 2,060 African Americans, 2,032 Latinas, 1,505 Asian Americans, 112 other race/ethnicity) diagnosed with primary invasive breast cancer between 1993 and 2007. In total, 3,047 deaths (1,570 breast cancer specific) were observed with a mean (SD) follow-up of 8.3 (3.5) years. Cox proportional hazards regression models were fit to data to estimate hazards ratios (HRs) and 95 % confidence intervals (CIs) for overall and breast cancer-specific mortality. Compared with non-Latina Whites, the HR of breast cancer-specific mortality was 1.13 (95 % CI 0.97-1.33) for African Americans, 0.84 (95 % CI 0.70-1.00) for Latinas, and 0.60 (95 % CI 0.37-0.97) for Asian Americans after adjustment for age, tumor characteristics, and select lifestyle factors. The CBCSC represents a large and racially/ethnically diverse cohort of breast cancer patients from California. This cohort will enable analyses to jointly consider a variety of clinical, lifestyle, and contextual factors in attempting to explain the long-standing disparities in breast cancer outcomes.

Postdiagnosis cruciferous vegetable consumption and breast cancer outcomes: a report from the After Breast Cancer Pooling Project

Cruciferous vegetables are a major source of glucosinolate-derived bioactive compounds such as isothiocyanates, which have been shown in animal and in vitro studies to inhibit cancer growth and progression. Few studies have investigated cruciferous vegetable intake after diagnosis and breast cancer outcomes. Using data from the After Breast Cancer Pooling Project, which includes prospective data from U.S. and Chinese breast cancer survivors, we evaluated the association of cruciferous vegetables with breast cancer outcomes. Analyses included 11,390 women diagnosed with stage I-III invasive breast cancer (1990-2006) from four cohorts. Cruciferous vegetable intake (g/day) was assessed using food frequency questionnaires (mean of 22 months postdiagnosis). Study heterogeneity was evaluated by the Q statistic; hazard ratios (HRs) and 95% confidence intervals (CI) were estimated using delayed-entry Cox regression models stratified by study. After a median follow-up of 9.0 years, 1,725 deaths and 1,421 recurrences were documented. In pooled analyses using study-specific quartiles, cruciferous vegetable intake was not associated with breast cancer outcomes, adjusting for known clinical prognostic factors and selected lifestyle factors. HRs (95% CIs) by increasing quartiles (reference = lowest quartile) were 1.08 (0.93-1.25), 1.01 (0.87-1.18), and 1.10 (0.95-1.28) for recurrence (P(trend) = 0.34) and 1.01 (0.88-1.15), 0.97 (0.84-1.11), and 0.99 (0.86-1.13) for total mortality (P(trend) = 0.84). No associations were observed for subgroups defined by estrogen receptor status, stage, or tamoxifen therapy. Cruciferous vegetable intake at approximately two years after diagnosis was not associated with recurrence or mortality. Our results do not support an association between postdiagnosis cruciferous vegetable intake and breast cancer outcomes.

Postdiagnosis supplement use and breast cancer prognosis in the After Breast Cancer Pooling Project

Vitamin supplement use after breast cancer diagnosis is common, but little is known about long-term effects on recurrence and survival. We examined postdiagnosis supplement use and risk of death or recurrence in the After Breast Cancer Pooling Project, a consortium of four cohorts of 12,019 breast cancer survivors from the United States and China. Post-treatment supplement use (vitamins A, B, C, D, E, and multivitamins) was assessed 1-5 years postdiagnosis. Associations with risk of recurrence, breast cancer-specific mortality, or total mortality were analyzed in Cox proportional hazards models separately by cohort. Individual cohort results were combined using random effects meta-analysis. Interactions with smoking, treatment, and hormonal status were examined. In multivariate models, vitamin E was associated with a decreased risk of recurrence (RR: 0.88; 95 % CI 0.79-0.99), and vitamin C with decreased risk of death (RR: 0.81; 95 % CI 0.72-0.92). However, when supplements were mutually adjusted, all associations were attenuated. There were no statistically significant associations with breast cancer mortality. The use of antioxidant supplements (multivitamins, vitamin C, or E) was not associated with recurrence, but was associated with a 16 % decreased risk of death (95 % CI 0.72-0.99). In addition, vitamin D was associated with decreased risk of recurrence among ER positive, but not ER negative tumors (p-interaction = 0.01). In this large consortium of breast cancer survivors, post-treatment use of vitamin supplements was not associated with increased risk of recurrence or death. Post-treatment use of antioxidant supplements was associated with improved survival, but the associations with individual supplement were difficult to determine. Stratification by ER status and considering antioxidants as a group may be more clinically relevant when evaluating associations with cancer risk and mortality.

The association between television watching time and all-cause mortality after breast cancer

PURPOSE

Sedentary time is a rapidly emerging independent risk factor for mortality in the general population, but its prognostic effect among cancer survivors is unknown. In a multiethnic, prospective cohort of breast cancer survivors, we hypothesized that television watching time would be independently associated with an increased risk of death from any cause.

METHODS

The Health, Eating, Activity, and Lifestyle Study cohort included 687 women diagnosed with local or regional breast cancer. On average 30 (±4) months postdiagnosis, women completed self-report assessments on time spent sitting watching television/videos in a typical day in the previous year. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for death from any cause (n = 89) during the 7 years of follow-up.

RESULTS

Television time (top tertile vs. bottom tertile) was positively related to risk of death (HR, 1.94; 95 % CI, 1.02, 3.66, p trend = 0.024), but the association was attenuated and not statistically significant after adjustment for aerobic moderate-vigorous intensity physical activity (HR, 1.70; 95 % CI, 0.89, 3.22, p trend = 0.14) and all covariates (HR, 1.39; 95 % CI, 0.69, 2.82, p trend = 0.48).

CONCLUSION

In this first published investigation on this topic, we did not observe a statistically significant multivariate-adjusted association between television watching time and risk of death among women diagnosed with breast cancer.

IMPLICATIONS FOR CANCER SURVIVORS

These results begin an evidence base on this topic that can be built upon to inform lifestyle recommendations for this expanding, aging population.

Leveraging epidemiology and clinical studies of cancer outcomes: recommendations and opportunities for translational research

As the number of cancer survivors continues to grow, research investigating the factors that affect cancer outcomes, such as disease recurrence, risk of second malignant neoplasms, and the late effects of cancer treatments, becomes ever more important. Numerous epidemiologic studies have investigated factors that affect cancer risk, but far fewer have addressed the extent to which demographic, lifestyle, genomic, clinical, and psychosocial factors influence cancer outcomes. To identify research priorities as well as resources and infrastructure needed to advance the field of cancer outcomes and survivorship research, the National Cancer Institute sponsored a workshop titled "Utilizing Data from Cancer Survivor Cohorts: Understanding the Current State of Knowledge and Developing Future Research Priorities" on November 3, 2011, in Washington, DC. This commentary highlights recent findings presented at the workshop, opportunities to leverage existing data, and recommendations for future research, data, and infrastructure needed to address high priority clinical and research questions. Multidisciplinary teams that include epidemiologists, clinicians, biostatisticians, and bioinformaticists will be essential to facilitate future cancer outcome studies focused on improving clinical care of cancer patients, identifying those at high risk of poor outcomes, and implementing effective interventions to ultimately improve the quality and duration of survival.

Postdiagnosis alcohol consumption and breast cancer prognosis in the after breast cancer pooling project

BACKGROUND

Alcohol consumption is an established risk factor for incident breast cancer. However, its role in breast cancer prognosis remains unclear.

METHODS

We conducted an investigation of postdiagnosis alcohol consumption with recurrence and mortality among 9,329 breast cancer patients in the After Breast Cancer Pooling Project. Women were diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors from three prospective US cohorts. Alcohol intake was assessed at cohort entry (mean 2.1 years postdiagnosis) using a food frequency questionnaire. HR and 95% confidence intervals (CI) were estimated using delayed entry Cox proportional hazards models with adjustment for known prognostic factors.

RESULTS

After a mean follow-up of 10.3 years, 1,646 recurrences and 1,543 deaths were ascertained. 5,422 women (58%) were considered drinkers (≥0.36 g/day of alcohol, ≥0.25 drinks/week) with a median of 5.3 g/day. Overall, compared with nondrinking, regular alcohol intake (≥6.0 g/day) was not associated with risk of recurrence (HR for 6 to less than 12 g/day, 1.03; 95% CI, 0.86-1.24; HR for 12 to less than 24 g/day, 1.12; 95% CI, 0.93-1.34; HR for ≥24 g/day, 1.04; 95% CI, 0.84-1.31). However, risk varied significantly by menopausal status (P for interaction < 0.05). Postmenopausal women who regularly consumed alcohol (≥6.0 g/day) had increased risk of recurrence (HR, 1.19; 95% CI, 1.01-1.40). Alcohol intake was not associated with mortality.

CONCLUSIONS

Regular alcohol consumption was not associated with breast cancer recurrence and total mortality overall, yet recurrence risk was only elevated in postmenopausal women.

IMPACT

The association between alcohol intake and recurrence may depend on menopausal status at breast cancer diagnosis.

Weight change and survival after breast cancer in the after breast cancer pooling project

BACKGROUND

Weight change after a breast cancer diagnosis has been linked to lower survival. To further understand effects of postdiagnostic weight variation on survival, we examined the relationship by comorbid status and initial body mass index (BMI).

METHODS

The current analysis included 12,915 patients with breast cancer diagnosed between 1990 and 2006 with stage I-III tumors from four prospective cohorts in the United States and China. HRs and 95% confidence intervals (CI) representing the associations of five weight change categories [within <5% (reference); 5%-<10% and ≥10% loss and gain] with mortality were estimated using Cox proportional hazards models.

RESULTS

Mean weight change was 1.6 kg. About 14.7% women lost and 34.7% gained weight. Weight stability in the early years postdiagnosis was associated with the lowest overall mortality risk. Weight loss ≥10% was related to a 40% increased risk of death (HR, 1.41; 95% CI, 1.14-1.75) in the United States and over three times the risk of death (HR, 3.25; 95% CI: 2.24, 4.73) in Shanghai. This association varied by prediagnosis BMI, and in the United States, lower survival was seen for women who lost weight and had comorbid conditions. Weight gain ≥10% was associated with a nonsignificant increased risk of death.

CONCLUSIONS

Prevention of excessive weight gain is a valid public health goal for breast cancer survivors. Although intentionality of weight loss could not be determined, women with comorbid conditions may be particularly at risk of weight loss and mortality.

IMPACT

Weight control strategies for breast cancer survivors should be personalized to the individual's medical history.

Soy food intake after diagnosis of breast cancer and survival: an in-depth analysis of combined evidence from cohort studies of US and Chinese women

BACKGROUND

Soy isoflavones have antiestrogenic and anticancer properties but also possess estrogen-like properties, which has raised concern about soy food consumption among breast cancer survivors.

OBJECTIVE

We prospectively evaluated the association between postdiagnosis soy food consumption and breast cancer outcomes among US and Chinese women by using data from the After Breast Cancer Pooling Project.

DESIGN

The analysis included 9514 breast cancer survivors with a diagnosis of invasive breast cancer between 1991 and 2006 from 2 US cohorts and 1 Chinese cohort. Soy isoflavone intake (mg/d) was measured with validated food-frequency questionnaires. HRs and 95% CIs were estimated by using delayed-entry Cox regression models, adjusted for sociodemographic, clinical, and lifestyle factors.

RESULTS

After a mean follow-up of 7.4 y, we identified 1171 total deaths (881 from breast cancer) and 1348 recurrences. Despite large differences in soy isoflavone intake by country, isoflavone consumption was inversely associated with recurrence among both US and Chinese women, regardless of whether data were analyzed separately by country or combined. No heterogeneity was observed. In the pooled analysis, consumption of ≥10 mg isoflavones/d was associated with a nonsignificant reduced risk of all-cause (HR: 0.87; 95% CI: 0.70, 1.10) and breast cancer-specific (HR: 0.83; 95% CI: 0.64, 1.07) mortality and a statistically significant reduced risk of recurrence (HR: 0.75; 95% CI: 0.61, 0.92).

CONCLUSION

In this large study of combined data on US and Chinese women, postdiagnosis soy food consumption of ≥10 mg isoflavones/d was associated with a nonsignificant reduced risk of breast cancer-specific mortality and a statistically significant reduced risk of recurrence.

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

Obese and underweight women who develop breast cancer may have poorer survival compared with normal-weight women. However, the optimal weight for best prognosis is still under study. We conducted a prospective investigation of pre-diagnosis body mass index (BMI) and mortality among 14,948 breast cancer patients in the After Breast Cancer Pooling Project. Breast cancer patients diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors were drawn from four prospective cohorts. Hazard ratios (HR) and 95% confidence intervals (CI) representing the associations of BMI categories (World Health Organization international classifications) with recurrence and mortality were estimated using delayed entry Cox proportional hazards models. Obese (30 to < 35 kg/m(2)), severely obese (35 to < 40 kg/m(2)), and morbidly obese (≥ 40 kg/m(2)) were examined. After a mean follow-up of 7.8 years, 2,140 deaths and 2,065 recurrences were documented. Both underweight (HR = 1.59; 95% CI: 1.18, 2.13) and morbidly obese women (HR = 1.81; 95% CI: 1.42, 2.32) had the greatest risk of overall mortality compared with normal weight (18.5-24.9 kg/m(2)) women. Severe obesity (HR = 1.09; 95% CI: 0.88, 1.36) and obesity (HR = 1.11; 95% CI: 0.97, 1.27) were related to small non-significant increased risks. Overweight (25.0-29.9 kg/m(2)) was not associated with any excess risk compared with normal weight. Similar associations were found for breast cancer death and non-breast cancer death but not recurrence. Women who were underweight and morbidly obese before breast cancer diagnosis were at the greatest risk of all-cause mortality. Morbidly obese women were also at increased risk of death from breast cancer. These results suggest that degree of obesity confers differential risk on survival.

A cross-cultural perspective on challenges facing comparative cancer survivorship research

Cancer survivorship research includes the study of physical, psychosocial, and economic consequences of cancer diagnosis and treatment among pediatric and adult cancer survivors. Historically, the majority of cancer survivorship studies were from the United States, but survivorship issues are increasingly being addressed in other developed countries. Cross-cultural studies remain, however, scarce. The degree to which knowledge attained may or may not be transferred across cultures, countries, or regions is not known. Some important challenges for comparative research are therefore discussed in a cross-cultural perspective. Several substantive and methodological challenges that complicate the execution of cross-cultural cancer survivorship research are presented with examples and discussed to facilitate comparative research efforts in the establishment of new survivorship cohorts and in the planning and implementation of survivorship studies. Comparative research is one key to understanding the nature of cancer survivorship, distinguishing modifiable from nonmodifiable factors at individual, hospital, societal, and system levels and may thus guide appropriate interventions. Lastly, suggested future courses of action within the field of comparative cancer survivorship research are provided.

Meeting the physical activity guidelines and survival after breast cancer: findings from the after breast cancer pooling project

The 2008 Physical Activity (PA) Guidelines recommend engaging in at least 2.5 h (10 MET-hours/week) of moderate intensity PA per week (defined as 4 METs) to reduce risk of morbidity and mortality. This analysis was conducted to investigate whether this recommendation can be extended to breast cancer survivors. Data from four studies of breast cancer survivors measuring recreational PA from semi-quantitative questionnaires a median of 23 months post-diagnosis (interquartile range 18-32 months) were pooled in the After Breast Cancer Pooling Project (n = 13,302). Delayed entry Cox proportional hazards models were applied in data analysis with adjustment for age, post-diagnosis body mass index, race/ethnicity, menopausal status, TNM stage, cancer treatment, and smoking history. Engaging in at least 10 MET-hours/week of PA was associated with a 27% reduction in all-cause mortality (n = 1,468 events, Hazard Ratio (HR) = 0.73, 95% CI, 0.66-0.82) and a 25% reduction in breast cancer mortality (n = 971 events, HR = 0.75, 95% CI 0.65-0.85) compared with women who did not meet the PA Guidelines (<10 MET-hours/week). Risk of breast cancer recurrence (n = 1,421 events) was not associated with meeting the PA Guidelines (HR = 0.96, 95% CI, 0.86-1.06). These data suggest that adhering to the PA guidelines may be an important intervention target for reducing mortality among breast cancer survivors.