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1.  Mortality Risk in Former Smokers with Breast Cancer: Pack-years vs. Smoking Status 
It is unclear why successful quitting at time of breast cancer diagnosis should remove risk from a significant lifetime of smoking. Studies concluding this may be biased by how smoking is measured in many epidemiological cohorts. In the late 1990s, a randomized trial of diet and breast cancer outcomes enrolled early-stage female breast cancer survivors diagnosed within the previous 4 years. Smoking history and key covariate measures were available at study entry for 2953 participants. Participants were followed for an average of 7.3 years (96% response rate). There were 10.1% deaths (83% from breast cancer). At enrollment, 55.2% were never smokers, 41.2% former smokers, and 4.6% current smokers. Using current smoking status in a Cox regression, there was no increased risk for former smokers for either all-cause mortality (HR=1.11; 95% CI=0.87, 1.41; p-value = 0.42) or breast cancer mortality. However, when we categorized on extensive lifetime exposure, former smokers with 20+ pack-years of smoking (25.8%) had a significantly higher risk of both all-cause (HR=1.77; 95% CI =1.17, 2.48; p-value = 0.0007) and breast cancer specific mortality (HR=1.62; 95% CI =1.11, 2.37; p-value = 0.01). Lifetime smoking exposure, not current status should be used to assess mortality risk among former smokers.
doi:10.1002/ijc.28241
PMCID: PMC3770774  PMID: 23649774
Breast cancer; smoking status; pack-years; mortality
2.  High prevalence of chronic kidney disease in a community survey of urban Bangladeshis: a cross-sectional study 
Background
The burden of chronic kidney disease (CKD) will rise in parallel with the growing prevalence of type two diabetes mellitus in South Asia but is understudied. Using a cross-sectional survey of adults living in a middle-income neighborhood of Dhaka, Bangladesh, we tested the hypothesis that the prevalence of CKD in this group would approach that of the U.S. and would be strongly associated with insulin resistance.
Methods
We enrolled 402 eligible adults (>30 years old) after performing a multi-stage random selection procedure. We administered a questionnaire, and collected fasting serum samples and urine samples. We used the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to estimate glomerular filtration rate, and sex-specific cut offs for albuminuria: > 1.9 mg/mmol (17 mg/g) for men, and >2.8 mg/mmol (25 mg/g) for women. We assessed health-related quality of life using the Medical Outcomes Study Short Form-12 (SF-12).
Results
A total of 357 (89%) participants with serum samples comprised the analytic cohort. Mean age of was 49.5 (± 12.7) years. Chronic kidney disease was evident in 94 (26%). Of the participants with CKD, 58 (62%) had albuminuria only. A participant with insulin resistance had a 3.6-fold increase in odds of CKD (95% confidence interval 2.1 to 6.4). Participants with stage three or more advanced CKD reported a decrement in the Physical Health Composite score of the SF-12, compared with participants without CKD.
Conclusion
We found an alarmingly high prevalence of CKD—particularly CKD associated with insulin resistance—in middle-income, urban Bangladeshis.
doi:10.1186/1744-8603-10-9
PMCID: PMC3944963  PMID: 24555767
Chronic kidney disease; Albuminuria; Insulin resistance; South Asia; Low-income countries
3.  High prevalence of type 2 diabetes among the urban middle class in Bangladesh 
BMC Public Health  2013;13:1032.
Background
The prevalence of type-2 diabetes and metabolic syndrome are increasing in the developing world; we assessed their prevalence among the urban middle class in Bangladesh.
Methods
In this cross-sectional survey (n = 402), we randomly selected consenting adults (≥ 30 years) from a middle-income neighborhood in Dhaka. We assessed demography, lifestyle, and health status, measured physical indices and blood pressure and obtained blood samples. We evaluated two primary outcomes: (1) type-2 diabetes (fasting blood glucose ≥ 7.0 mmol/L or hemoglobin A1C ≥ 6.5% (48 mmol/mol) or diabetes medication use) and (2) insulin resistance (type-2 diabetes or metabolic syndrome using International Diabetes Federation criteria).
Results
Mean age and Quételet’s (body mass) index were 49.4 ± 12.6 years and 27.0 ± 5.1 kg/m2; 83% were married, 41% had ≥12 years of education, 47% were employed, 47% had a family history of diabetes. Thirty-five percent had type-2 diabetes and 45% had metabolic syndrome. In multivariate models older age and family history of diabetes were significantly associated with type-2 diabetes. Older age, female sex, overweight or obese, high wealth index and positive family history of diabetes were significantly associated with insulin resistance. Participants with type-2 diabetes or insulin resistance had significantly poorer physical health only if they had associated cardiovascular disease.
Conclusions
The prevalence of type-2 diabetes and metabolic syndrome among the middle class in Dhaka is alarmingly high. Screening services should be implemented while researchers focus on strategies to lessen the incidence and morbidity associated with these conditions.
doi:10.1186/1471-2458-13-1032
PMCID: PMC3924340  PMID: 24172217
4.  Prognosis following the use of complementary and alternative medicine in women diagnosed with breast cancer 
Objective
The purpose of this study was to assess whether CAM use affected breast cancer prognosis in those who did not receive systemic therapy.
Design
Secondary data analysis of baseline/survey data from the Women's Healthy Eating and Living Study (WHEL). 2562 breast cancer survivors participating in the study completed baseline assessments and a CAM use questionnaire. Cox regression models were conducted to evaluate the use of CAM modalities and dietary supplements on time to an additional breast cancer event (mean follow-up = 7.3 years).
Setting
A US-based multi-site randomized dietary trial.
Outcome
Time to additional breast cancer events.
Results
The women who did not receive any systemic treatment had a higher risk for time to additional breast cancer events (HR=1.9, 95% CI: 1.32, 2.73) and for all-cause mortality (HR=1.7, 95% CI: 1.06, 2.73) compared to those who had received systemic treatment. Among 177 women who did not receive systemic treatment, CAM use was not significantly related to additional breast cancer events. There were no significant differences between high supplement users ( ≥ 3 formulations per day) and low supplement users in either risk for additional breast cancer events.
Conclusion
The risk for an additional breast cancer event and/or death was higher for those who did not receive any systemic treatments; the use dietary supplements or CAM therapies did not change this risk. This indicates that complementary and alternative therapies did not alter the outcome of breast cancer and should not be used in place of standard treatment.
doi:10.1016/j.ctim.2012.04.002
PMCID: PMC3413169  PMID: 22863642
breast cancer; complementary and alternative medicine; dietary supplements; long- term prognosis; alternative cancer treatment
5.  Self-perceived physical health predicts cardiovascular disease incidence and death among postmenopausal women 
BMC Public Health  2013;13:468.
Background
Physical and Mental Component Summary (PCS, MCS, respectively) scales of SF- 36 health-related-quality-of-life have been associated with all-cause and cardiovascular disease (CVD) mortality. Their relationships with CVD incidence are unclear. This study purpose was to test whether PCS and/or MCS were associated with CVD incidence and death.
Methods
Postmenopausal women (aged 50–79 years) in control groups of the Women’s Health Initiative clinical trials (n = 20,308) completed the SF-36 and standardized questionnaires at trial entry. Health outcomes, assessed semi-annually, were verified with medical records. Cox regressions assessed time to selected outcomes during the trial phase (1993–2005).
Results
A total of 1075 incident CVD events, 204 CVD-specific deaths, and 1043 total deaths occurred during the trial phase. Women with low versus high baseline PCS scores had less favorable health profiles at baseline. In multivariable models adjusting for baseline confounders, participants in the lowest PCS quintile (reference = highest quintile) exhibited 1.8 (95%CI: 1.4, 2.3), 4.7 (95%CI: 2.3, 9.4), and 2.1 (95%CI: 1.7, 2.7) times greater risk of CVD incidence, CVD-specific death, and total mortality, respectively, by trial end; whereas, MCS was not significantly associated with CVD incidence or death.
Conclusion
Physical health, assessed by self-report of physical functioning, is a strong predictor of CVD incidence and death in postmenopausal women; similar self-assessment of mental health is not. PCS should be evaluated as a screening tool to identify older women at high risk for CVD development and death.
doi:10.1186/1471-2458-13-468
PMCID: PMC3706392  PMID: 23672763
Physical component summary; Mental component summary; Cardiovascular disease; All-cause death
6.  Cardiovascular diseases and Type 2 Diabetes in Bangladesh: A systematic review and meta-analysis of studies between 1995 and 2010 
BMC Public Health  2012;12:434.
Background
Belief is that chronic disease prevalence is rising in Bangladesh since death from them has increased. We reviewed published cardiovascular (CVD) and Type 2 Diabetes Mellitus (T2DM) studies between 1995 and 2010 and conducted a meta-analysis of disease prevalence.
Methods
A systematic search of CVD and T2DM studies yielded 29 eligible studies (outcome: CVD only = 12, T2DM only = 9, both = 8). Hypertension (HTN) was the primary outcome of CVD studies. HTN and T2DM were defined with objective measures and standard cut-off values. We assessed the study quality based on sampling frame, sample size, and disease evaluation. Random effects models calculated pooled disease prevalence (95% confidence interval) in studies with general population samples (n = 22).
Results
The pooled HTN and T2DM prevalence were 13.7% (12.1%–15.3%) and 6.7% (4.9%–8.6%), respectively. Both diseases exhibited a secular trend by 5-year intervals between 1995 and 2010 (HTN = 11.0%, 12.8%, 15.3%, T2DM = 3.8%, 5.3%, 9.0%). HTN was higher in females (M vs. F: 12.8% vs.16.1%) but T2DM was higher in males (M vs. F: 7.0% vs. 6.2%) (non-significant). Both HTN and T2DM were higher in urban areas (urban vs. rural: 22.2% vs. 14.3% and 10.2% vs. 5.1% respectively) (non-significant). HTN was higher among elderly and among working professionals. Both HTN and T2DM were higher in ‘high- quality’ studies.
Conclusions
There is evidence of a rising secular trend of HTN and T2DM prevalence in Bangladesh. Future research should focus on the evolving root causes, incidence, and prognosis of HTN and T2DM.
doi:10.1186/1471-2458-12-434
PMCID: PMC3487781  PMID: 22694854
7.  Classification of CAM Use and its Correlates in Early Stage Breast Cancer Patients 
Integrative cancer therapies  2011;10(2):138-147.
Hypothesis
Self-reported use of complementary and alternative medicine (CAM) has been shown to increase following a cancer diagnosis, and breast cancer survivors are the heaviest users among cancer survivors. The aim of this study was to determine whether the prevalence estimate of CAM use varied according to classification of CAM. We used a comprehensive system to classify CAM users and test differences in demographic, lifestyle, quality of life, and cancer characteristics among them.
Study Design and Methods
Participants were 2562 breast cancer survivors participating in the Women's Healthy Eating and Living (WHEL) Study, aged 28-74 years. A structured telephone interview assessed CAM use, questioning about specific CAM practices, and whether use was related to cancer. We examined CAM use in relation to demographics, health behaviors, and quality of life.
Results
Approximately 80% of the women used CAM for general purposes but only 50% reported CAM use for cancer purposes. Visual imagery, spiritual healing, and meditation were the most frequently used practices for cancer purposes. CAM use, defined as consulting a CAM practitioner and regular use, was significantly related to younger age, higher education, increased fruit & vegetable intake, and lower body mass index (p < .05). CAM users who had seen a practitioner were also more likely to report poor physical and mental health than non-CAM users (p < .05). CAM use was not associated with changes in physical and mental health between study baseline and 1-year follow-up.
Conclusion
This study addressed important differences in the classification of CAM use among breast cancer survivors. Future studies need to further test the potential benefits and risks associated with CAM use.
doi:10.1177/1534735410392578
PMCID: PMC3126886  PMID: 21382963
8.  Improvement in Self-Reported Physical Health Predicts Longer Survival Among Women with a History of Breast Cancer 
Purpose
Physical health-related quality of life scores have been, inconsistently, associated with breast cancer prognosis. This analysis examined whether change in physical health scores were related to outcomes in women with a history of breast cancer.
Methods
2343 breast cancer survivors in a randomized diet trial provided self-reported assessment of physical health-related quality of life at baseline and year 1. Based on change in physical health score, participants were grouped into subpopulations of decreased physical health, no/minimal changes, and increased physical health. Cox regression analysis assessed whether change in physical health (from baseline to year 1) predicted disease-free and overall survival; hazard ratio (HR) was the measure of association.
Results
There were 294 additional breast cancer events and 162 deaths among women followed for 7.3 years. Improvements in physical health were associated with younger age, lower BMI, being employed, not receiving tamoxifen, lower physical activity, and lower baseline physical and mental health. There was no association of change in physical health with additional breast cancer events or mortality among women diagnosed ≤ 2 years before study enrollment. However, among women who entered the study >2 years post diagnosis, the HR for increased compared to decreased physical health was 0.38 (95% CI, 0.16 to 0.85) for all-cause mortality.
Conclusions
These results appear to support testing an intervention to improve physical health in breast cancer patients among patients after the acute stage of treatment.
doi:10.1007/s10549-010-1236-x
PMCID: PMC3306248  PMID: 21042931
breast cancer; physical health; survival; mortality
9.  Dietary Intake, Supplement Use, and Survival Among Women Diagnosed with Early Stage Breast Cancer 
Nutrition and cancer  2011;63(3):327-333.
Background
Previous studies examining the relationship between micronutrient intakes and survival following diagnosis of breast cancer have reported mixed results. This may be partly due to considerable variance in amounts of micronutrients consumed from diet and supplements across studies.
Methods
Early stage breast cancer survivors (n=3081) completed four 24-hour dietary and supplement recalls at the baseline assessment (1995 to 2000) and were followed for a median of 9.0 years. Mean micronutrient intakes were compared to dietary reference intakes (DRI) to assess micronutrient adequacy for both users and non-users of supplements. Cox regressions were performed to assess whether intakes of selected micronutrients were associated with all-cause mortality.
Results
412 deaths occurred between baseline and August 2009. Among these women, more supplement users had adequate micronutrient intakes than non-users for 15 out of 17 micronutrients. Less than 10% of supplement users (< 2% of non-supplement users) reported levels that exceeded the tolerable upper limit for each micronutrient except magnesium. After adjusting for age, tumor characteristics, and health status variables, micronutrient intakes were not significantly associated with all-cause mortality.
Conclusion
Dietary supplements may improve overall micronutrient intakes of breast cancer survivors. However, vitamin and mineral intakes were not associated with all-cause mortality.
doi:10.1080/01635581.2011.535957
PMCID: PMC3078826  PMID: 21391124
dietary intake; supplement use; breast cancer survival
10.  Poor Physical Health Predicts Time to Additional Breast Cancer Events and Mortality in Breast Cancer Survivors 
Psycho-Oncology  2011;20(3):252-259.
Background
Health-related quality of life (HRQOL) has been hypothesized to predict time to additional breast cancer events and all-cause mortality in breast cancer survivors.
Methods
Women with early stage breast cancer (n=2967) completed the SF-36 (mental and physical health-related quality of life) and standardized psychosocial questionnaires to assess social support, optimism, hostility, and depression prior to randomization into a dietary trial. Cox regression was performed to assess whether these measures of quality of life and psychosocial functioning predicted time to additional breast cancer events and all-cause mortality; hazard ratios were the measure of association.
Results
There were 492 additional breast cancer events and 301 deaths occurred over a median 7.3 years (range: 0.01–10.8 years) of follow-up. In multivariate models, poorer physical health was associated with both decreased time to additional breast cancer events and all-cause mortality (p trend=0.005 and 0.004, respectively), while greater hostility predicted additional breast cancer events only (p trend=0.03). None of the other psycho-social variables predicted either outcome. The hazard ratios comparing persons with poor (bottom two quintiles) to better (top three quintiles) physical health were 1.42 (95% CI: 1.16, 1.75) for decreased time to additional breast cancer events and 1.37 (95% CI: 1.08, 1.74) for all-cause mortality. Potentially modifiable factors associated with poor physical health included higher BMI, lower physical activity, lower alcohol consumption, and more insomnia (p<0.05 for all).
Conclusion
Interventions to improve physical health should be tested as a means to increase time to additional breast cancer events and mortality among breast cancer survivors.
doi:10.1002/pon.1742
PMCID: PMC3297415  PMID: 20878837
physical health; breast cancer; oncology; survival
11.  Clinically Defined Type 2 Diabetes Mellitus and Prognosis in Early-Stage Breast Cancer 
Journal of Clinical Oncology  2010;29(1):54-60.
Purpose
Self-reported diabetes has been associated with poor breast cancer outcomes. Research is needed to investigate the relationship between biologically determined glycemic control and breast cancer prognosis.
Methods
Archived baseline blood samples from the Women's Healthy Eating and Living Study were used to measure hemoglobin A1C (HbA1C) among 3,003 survivors of early-stage breast cancer (age of diagnosis, 28 to 70 years) observed for a median of 7.3 years for additional breast cancer events and 10.3 years for all-cause mortality. HbA1C levels provide an accurate, precise measure of chronic glycemic levels. Cox regression analysis was performed to assess whether baseline HbA1C levels predicted disease-free and overall survival.
Results
Only 5.8% of women had chronic hyperglycemia (defined as HbA1C levels ≥ 6.5%). Those with HbA1C ≥ 6.5% were older and more likely to be less educated, have nonwhite ethnicity, be obese, and have more advanced breast cancer at diagnosis. HbA1C was significantly associated with overall survival (Ptrend < .001). After adjusting for confounders, risk of all-cause mortality was twice as high in women with HbA1C ≥ 7.0% compared with women with HbA1C less than 6.5% (hazard ratio [HR], 2.35; 95% CI, 1.56 to 3.54). For disease-free survival, there was a nonsignificant 30% increase in risk for HbA1C levels ≥ 7.0% (HR, 1.26; 95% CI, 0.78 to 2.02). During study follow-up, previously diagnosed rather than undiagnosed diabetes seemed to account for the increased risk.
Conclusion
Chronic hyperglycemia is statistically significantly associated with reduced overall survival in survivors of early-stage breast cancer. Further study of diabetes and its relationship to breast cancer outcomes is warranted.
doi:10.1200/JCO.2010.29.3183
PMCID: PMC3055860  PMID: 21115861
12.  Medical Comorbidities Predict Mortality in Women with a History of Early Stage Breast Cancer 
Introduction
This analysis was conducted to determine whether comorbid medical conditions predict additional breast cancer events and all-cause mortality in women with a history of early stage breast cancer.
Methods
Women (n=2542) participating in a randomized diet trial completed a selfadministered questionnaire regarding whether they were currently being treated for a wide variety of diseases (cardiovascular, diabetes, gallbladder, gastrointestinal, arthritis, and osteoporosis) and conditions (high blood pressure, elevated cholesterol level). Height and weight were measured at baseline. Participants were followed for a median of 7.3 years (range 0.8 to 15.0). Cox regression analysis was performed to assess whether comorbidities predicted disease-free and overall survival; hazard ratio (HR) was the measure of association.
Results
Overall, there were 406 additional breast cancer events and 242 deaths. Participants with diabetes had over 2-fold the risk of additional breast cancer events (HR 2.1, 95% CI: 1.3, 3.4) and mortality (HR 2.5, 95% CI: 1.4, 4.4). The presence of multiple comorbidities did not statistically significantly predict additional breast cancer events. However, compared to no comorbidities, participants with 3 or more comorbidities had a HR of 2.1, 95% CI: 1.3, 3.3 for mortality.
Conclusion
Type 2 diabetes was associated with poor breast cancer prognosis. Given that 85 percent of deaths were caused by breast cancer, these findings suggest that multiple comorbidities may reduce the likelihood of surviving additional breast cancer events.
doi:10.1007/s10549-010-0732-3
PMCID: PMC2895945  PMID: 20077000
comorbidities; breast cancer; mortality
13.  Physical and Mental Health Correlates of Pregnancy Following Breast Cancer 
Psycho-oncology  2010;19(5):517-524.
Introduction
The safety of pregnancy after breast cancer is an important issue for many younger breast cancer survivors and their health care providers. Current research does not indicate that pregnancy negatively affects survival, but the “healthy mother bias,” suggesting that survivors who go on to become pregnant are a self-selected healthier group based on their prognosis, has led to cautious interpretation of these findings. No studies have systematically evaluated the potential for this bias.
Methods
This nested case-control study includes 81 younger participants from the Women’s Healthy Eating and Living Study (WHEL) (N=3088). Our sample includes 27 cases who had children after breast cancer and 54 controls, matched on age and stage at diagnosis. We used hierarchical linear modeling to accommodate longitudinal data with individuals nested within matched sets (cases and controls). The primary aim was to evaluate the association between summary scores of health and childbearing after breast cancer. Covariates were added for adjustment and to improve model precision.
Results
Controlling for other variables in the model, physical health scores were not different between cases and controls (B=0.14, p=0.96). Mental health scores were marginally higher among cases (B=6.40, p=0.08), as compared to controls, a difference considered clinically significant.
Conclusion
This preliminary study did not find evidence of a healthy mother bias based on physical health. However, mental health was 6 points higher (p=0.08) among those who had children, indicating that the role of mental health needs evaluation in future research. Larger studies are needed to verify these findings.
doi:10.1002/pon.1614
PMCID: PMC2861788  PMID: 20425779
14.  Low To Moderate Alcohol Intake Is Not Associated with Increased Mortality after Breast Cancer 
Background
Both alcohol consumption and obesity have been linked with breast cancer morbidity and mortality. An inverse association between alcohol intake and obesity suggests possible confounding between these variables (and perhaps other factors) with breast cancer outcomes.
Methods
Alcohol intake (beer, wine, spirits, and total) was examined in 3088 women previously diagnosed and treated for breast cancer, within an intervention trial that targeted vegetables, fiber, and fat but not alcohol or weight loss. Factors associated with baseline alcohol intake were included in Cox proportional hazards models for recurrence and mortality.
Results
Alcohol intake was significantly associated with higher education and physical activity levels. Neither light alcohol intake nor obesity was significantly associated with breast cancer recurrence, but moderate alcohol intake > 300 g/month was protective against all-cause mortality (HR = 0.69, CI=0.49-0.97) in a proportional hazards model adjusted for obesity. Obese women were 61% more likely to be nondrinkers than drinkers, and 76% more likely to be light drinkers than moderate/heavy drinkers. In non-obese women, alcohol intake > 10 g/month was associated with lower risk of all-cause mortality (HR = 0.68, 95% CI = 0.51-0.91).
Conclusion
Light alcohol intake, regardless of body weight, did not increase the risk of breast cancer recurrence or all-cause mortality in this cohort of middle-aged women previously diagnosed with breast cancer. Alcohol intake was associated with other favorable prognostic indicators that may explain its apparent protective effect in non-obese women.
doi:10.1158/1055-9965.EPI-09-0927
PMCID: PMC2836421  PMID: 20160253
alcohol; breast cancer; obesity; mortality; recurrence
15.  Physical activity, additional breast cancer events, and mortality among early-stage breast cancer survivors: findings from the WHEL Study 
Cancer Causes & Control  2010;22(3):427-435.
Objective
Research suggests that physical activity is associated with improved breast cancer survival, yet no studies have examined the association between post-diagnosis changes in physical activity and breast cancer outcomes. The aim of this study was to determine whether baseline activity and 1-year change in activity are associated with breast cancer events or mortality.
Methods
A total of 2,361 post-treatment breast cancer survivors (Stage I–III) enrolled in a randomized controlled trial of dietary change completed physical activity measures at baseline and one year. Physical activity variables (total, moderate–vigorous, and adherence to guidelines) were calculated for each time point. Median follow-up was 7.1 years. Outcomes were invasive breast cancer events and all-cause mortality.
Results
Those who were most active at baseline had a 53% lower mortality risk compared to the least active women (HR = 0.47; 95% CI: 0.26, 0.84; p = .01). Adherence to activity guidelines was associated with a 35% lower mortality risk (HR = 0.65, 95% CI: 0.47, 0.91; p < .01). Neither baseline nor 1-year change in activity was associated with additional breast cancer events.
Conclusions
Higher baseline (post-treatment) physical activity was associated with improved survival. However, change in activity over the following year was not associated with outcomes. These data suggest that long-term physical activity levels are important for breast cancer prognosis.
doi:10.1007/s10552-010-9714-3
PMCID: PMC3042101  PMID: 21184262
Exercise; Recurrence; Survival; Behavior; Lifestyle
16.  Time-Varying Effects of Prognostic Factors Associated With Disease-Free Survival in Breast Cancer 
American Journal of Epidemiology  2009;169(12):1463-1470.
Early detection and effective treatments have dramatically improved breast cancer survivorship, yet the risk of relapse persists even 15 years after the initial diagnosis. It is important to identify prognostic factors for late breast cancer events. The authors investigated time-varying effects of tumor characteristics on breast-cancer-free survival using data on 3,088 breast cancer survivors from 4 US states who participated in a randomized dietary intervention trial in 1995–2006, with maximum follow-up through 15 years (median, 9 years). A piecewise constant penalized spline approach incorporating time-varying coefficients was adopted, allowing for deviations from the proportional hazards assumption. This method is more flexible than standard approaches, provides direct estimates of hazard ratios across time intervals, and is computationally tractable. Having a stage II or III tumor was associated with a 3-fold higher hazard of breast cancer than having a stage I tumor during the first 2.5 years after diagnosis; this hazard ratio decreased to 2.1 after 7.7 years, but higher tumor stage remained a significant risk factor. Similar diminishing effects were found for poorly differentiated tumors. Interestingly, having a positive estrogen receptor status was protective up to 4 years after diagnosis but detrimental after 7.7 years (hazard ratio = 1.5). These results emphasize the importance of careful statistical modeling allowing for possibly time-dependent effects in long-term survivorship studies.
doi:10.1093/aje/kwp077
PMCID: PMC2733768  PMID: 19403844
breast neoplasms; proportional hazards models; survival
17.  Dietary Pattern Influences Breast Cancer Prognosis in Women Without Hot Flashes: The Women's Healthy Eating and Living Trial 
Journal of Clinical Oncology  2009;27(3):352-359.
Purpose
To determine whether a low-fat diet high in vegetables, fruit, and fiber differentially affects prognosis in breast cancer survivors with hot flashes (HF) or without HF after treatment.
Patients and Methods
A secondary analysis was conducted on 2,967 breast cancer survivors, age 18 to 70 years, who were randomly assigned between 1995 and 2000 in a multicenter, controlled trial of a dietary intervention to prevent additional breast cancer events and observed through June 1, 2006. We compared the dietary intervention group with a group who received five-a-day dietary guidelines.
Results
Independent of HF status, a substantial between-group difference among those who did and did not receive dietary guidelines was achieved and maintained at 4 years in intake of vegetable/fruit servings per day (54% higher; 10 v 6.5 servings/d, respectively), fiber (31% higher; 25.5 v 19.4 g/d, respectively), and percent energy from fat (14% lower; 26.9% v 31.3%, respectively). Adjusting for tumor characteristics and antiestrogen treatment, HF-negative women assigned to the intervention had 31% fewer events than HF-negative women assigned to the comparison group (hazard ratio [HR] = 0.69; 95% CI, 0.51 to 0.93; P = .02). The intervention did not affect prognosis in the women with baseline HFs. Furthermore, compared with HF-negative women assigned to the comparison group, HF-positive women had significantly fewer events in both the intervention (HR = 0.77; 95% CI, 0.59 to 1.00; P = .05) and comparison groups (HR = 0.65; 95% CI, 0.49 to 0.85; P = .002).
Conclusion
A diet with higher vegetable, fruit, and fiber and lower fat intakes than the five-a-day diet may reduce risk of additional events in HF-negative breast cancer survivors. This suggestive finding needs confirmation in a trial in which it is the primary hypothesis.
doi:10.1200/JCO.2008.16.1067
PMCID: PMC2645853  PMID: 19075284
18.  The Impact of a Long-Term Reduction in Dietary Energy Density on Body Weight Within a Randomized Diet Trial 
Nutrition and cancer  2008;60(1):31-38.
We examined the effect of dietary energy density change on body weight in participants of a randomized trial. Intervention participants markedly increased fruit and vegetable intake while reducing energy intake from fat. Participants were 2,718 breast cancer survivors, aged 26−74 yr, with baseline mean body mass index of 27.3 kg/m2 (SD = 6.3). We assessed dietary intake by sets of four 24-h dietary recalls and validated with plasma carotenoid concentrations. Weight and height were measured at baseline, 1 yr, and 4 yr. Dietary energy density was calculated using food but excluding beverages. Intervention participants significantly reduced dietary energy density compared to controls and maintained it over 4 yr—both in cross-sectional (P < 0.0001) and longitudinal (Group × Time interaction, P < 0.0001) analyses. Total energy intake or physical activity did not vary between groups. The intervention group had a small but significant weight loss at 1 yr (Group × Time interaction, P < 0.0001), but no between-group weight difference was observed at 4 yr. Our study showed that reducing dietary energy density did not result in a reduction in total energy intake and suggests that this strategy alone is not sufficient to promote long-term weight loss in a free-living population.
doi:10.1080/01635580701621320
PMCID: PMC2575113  PMID: 18444133
19.  Practices and impact of primary outcome adjustment in randomized controlled trials: meta-epidemiologic study 
Objective To assess adjustment practices for primary outcomes of randomized controlled trials and their impact on the results.
Design Meta-epidemiologic study.
Data sources 25 biomedical journals with the highest impact factor according to Journal Citation Reports 2009.
Study selection Randomized controlled trials published in print in 2009 that reported primary outcomes. The search yielded 684 eligible papers of randomized controlled trials, of which 200 were randomly selected.
Data extraction Two researchers independently extracted data on study population, intervention, primary outcome, and the adjustment plan for primary outcomes. They also recorded the magnitude and statistical significance of the intervention effect with and without adjustments, and estimated whether adjustment made a difference in the level of nominal significance. They also compared the analysis plan for model adjustment in the published trial versus the trial protocol with information on the protocol collected from registries, design papers, and communication with all corresponding authors.
Results 54% of the trials used stratified randomization, 96% presented baseline characteristics in the compared arms, and 46% also evaluated differences in baseline factors with statistical testing. Half of the trials performed adjusted analyses for the main outcome, as the sole analysis (29%) or along with unadjusted analyses (21%). Adjustment for stratification variables and for baseline variables was performed in 39% (42/108) and 42% (84/199) of the trials, respectively. Among 40 comparisons with both adjusted and unadjusted analyses, 43% had statistically significant effects, 40% had non-significant effects, and 18% had significant effects with only one of the two analyses, but not with the other. Information on analysis plan regarding model adjustment was available in 6% (9/162) of trial registry entries, 78% (21/27) of design papers, and 74% (40/54) of protocols obtained from authors. The analysis plan disagreed between the published trial and the registry, protocol, or design paper in 47% (28/60) of the studies.
Conclusions There is large diversity on whether and how analyses of primary outcomes are adjusted in randomized controlled trials and these choices can sometimes change the nominal significance of the results. Registered protocols should explicitly specify adjustments plans for main outcomes and analysis should follow these plans.
doi:10.1136/bmj.f4313
PMCID: PMC3709831  PMID: 23851720

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