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.     

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

The After Breast Cancer Pooling Project was established to examine the role of physical activity, adiposity, dietary factors, supplement use, and quality of life (QOL) in breast cancer prognosis. This paper presents pooled and harmonized data on post-diagnosis lifestyle factors, clinical prognostic factors, and breast cancer outcomes from four prospective cohorts of breast cancer survivors (three US-based and one from Shanghai, China) for 18,314 invasive breast cancer cases diagnosed between 1976 and 2006. Most participants were diagnosed with stage I-II breast cancer (84.7%). About 60% of breast tumors were estrogen receptor (ER)+/progesterone receptor (PR)+; 21% were ER-/PR-. Among 8,118 participants with information on HER-2 tumor status, 74.8% were HER-2- and 18.5% were HER-2+. At 1-2 years post-diagnosis (on average), 17.9% of participants were obese (BMI ≥ 30 kg/m2), 32.6% were overweight (BMI 25-29 kg/m2), and 59.9% met the 2008 Physical Activity Guidelines for Americans (≥ 2.5 h per week of moderate activity). During follow-up (mean = 8.4 years), 3,736 deaths (2,614 from breast cancer) and 3,564 recurrences have been documented. After accounting for differences in year of diagnosis and timing of post-diagnosis enrollment, five-year overall survival estimates were similar across cohorts. This pooling project of 18,000 breast cancer survivors enables the evaluation of associations of post-diagnosis lifestyle factors, QOL, and breast cancer outcomes with an adequate sample size for investigation of heterogeneity by hormone receptor status and other clinical predictors. The project sets the stage for international collaborations for the investigation of modifiable predictors for breast cancer outcomes.     

Postdiagnosis dietary factors,supplement use and breast cancer prognosis: Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

Little is known about how diet might influence breast cancer prognosis. The current systematic reviews and meta-analyses summarise the evidence on postdiagnosis dietary factors and breast cancer outcomes from randomised controlled trials and longitudinal observational studies. PubMed and Embase were searched through 31st October 2021. Random-effects linear dose-response meta-analysis was conducted when at least three studies with sufficient information were available. The quality of the evidence was evaluated by an independent Expert Panel. We identified 108 publications. No meta-analysis was conducted for dietary patterns, vegetables, wholegrains, fish, meat, and supplements due to few studies, often with insufficient data. Meta-analysis was only possible for all-cause mortality with dairy, isoflavone, carbohydrate, dietary fibre, alcohol intake and serum 25-hydroxyvitamin D (25(OH)D), and for breast cancer-specific mortality with fruit, dairy, carbohydrate, protein, dietary fat, fibre, alcohol intake and serum 25(OH)D. The results, with few exceptions, were generally null. There was limited-suggestive evidence that predefined dietary patterns may reduce the risk of all-cause and other causes of death; that isoflavone intake reduces the risk of all-cause mortality (relative risk (RR) per 2 mg/day: 0.96, 95% confidence interval (CI): 0.92-1.02), breast cancer-specific mortality (RR for high vs low: 0.83, 95% CI: 0.64-1.07), and recurrence (RR for high vs low: 0.75, 95% CI: 0.61-0.92); that dietary fibre intake decreases all-cause mortality (RR per 10 g/day: 0.87, 95% CI: 0.80-0.94); and that serum 25(OH)D is inversely associated with all-cause and breast cancer-specific mortality (RR per 10 nmol/L: 0.93, 95% CI: 0.89-0.97 and 0.94, 95% CI: 0.90-0.99, respectively). The remaining associations were graded as limited-no conclusion.     

Vitamin supplement use and risk for breast cancer: the Shanghai Breast Cancer Study

Objective The influence of vitamin supplements on breast cancer risk is unclear and the interactive effects of dietary and supplemental sources are unknown. This study investigated (1) the association between self-reported vitamin supplement use (multivitamin, A, B, C, and E) and breast cancer and (2) the combined effect of vitamin supplements in relation to dietary vitamin intakes on breast cancer risk. Methods The Shanghai Breast Cancer Study was a population-based case-control study conducted in Shanghai in 1996-1998 (Phase I) and 2002-2004 (Phase II). Participants were aged 25-64 (Phase I) and 20-70 years (Phase II). The analyses included 3,454 incident breast cancer cases and 3,474 controls. Unconditional logistic regression models were used to determine adjusted odds ratios (ORs) for breast cancer risk associated with vitamin supplement use. Results Overall, breast cancer risk was not related to any vitamin supplement intake. However, a 20% reduction in breast cancer risk was observed with vitamin E supplement use among women with low-dietary vitamin E intake (OR = 0.8; 95% confidence interval (CI), 0.6-1.0). A non-significant 20% risk reduction was observed among vitamin B supplement users with low B dietary intake (OR = 0.8; 95% CI, 0.6-1.1). Frequent use of a vitamin B supplement was adversely associated with breast cancer risk among those with high dietary vitamin B intake (OR = 1.4; 95% CI: 0.9-2.1; P for interaction = 0.07). Conclusions This study suggests that vitamins E and B supplements may confer protection against breast cancer among women who have low dietary intake of those vitamins.     

Antioxidant supplement use after breast cancer diagnosis and mortality in the Life After Cancer Epidemiology (LACE) cohort

BACKGROUND:

There is concern that antioxidant supplement use during chemotherapy and radiation therapy may decrease treatment effects, yet the effects of such supplements on recurrence and survival are largely unknown.

METHODS:

The authors prospectively examined the associations between antioxidant use after breast cancer (BC) diagnosis and BC outcomes in 2264 women in the Life After Cancer Epidemiology (LACE) cohort. The cohort included women who were diagnosed with early stage, primary BC from 1997 to 2000 who enrolled, on average, 2 years postdiagnosis. Baseline data were collected on antioxidant supplement use since diagnosis and other factors. BC recurrence and mortality were ascertained, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using delayed entry Cox proportional hazards models. All tests of statistical significance were 2‐sided.

RESULTS:

Antioxidant supplement use after diagnosis was reported by 81% of women. Among antioxidant users, frequent use of vitamin C and vitamin E was associated with a decreased risk of BC recurrence (vitamin C: HR, 0.73; 95% CI, 0.55‐0.97; vitamin E: HR, 0.71; 95% CI, 0.54‐0.94); and vitamin E use was associated with a decreased risk of all‐cause mortality (HR, 0.76; 95% CI, 0.58‐1.00). Conversely, frequent use of combination carotenoids was associated with increased risk of death from BC (HR, 2.07; 95% CI, 1.21‐3.56) and all‐cause mortality (HR, 1.75; 95% CI, 1.13‐2.71).

CONCLUSIONS:

Frequent use of vitamin C and vitamin E in the period after BC diagnosis was associated with a decreased likelihood of recurrence, whereas frequent use of combination carotenoids was associated with increased mortality. The effects of antioxidant supplement use after diagnosis likely differ by type of antioxidant. Cancer 2012. © 2011 American Cancer Society.     

Sleep duration and breast cancer risk in the Breast Cancer Detection Demonstration Project follow-up cohort

Background:

Short sleep has been hypothesised to increase the risk of breast cancer. However, little is known about the association between sleep and different subtypes of breast cancer defined by hormone receptor status.

Methods:

Among 40 013 women in the Breast Cancer Detection Demonstration Project, including 1846 incident breast cancer cases, we prospectively examined self-reported weekday and weekend sleep duration in relation to breast cancer risk. We used multivariate Cox proportional hazards regression models to estimate relative risks (RRs) and 95% confidence intervals (CIs).

Results:

We found no association between sleep and overall breast cancer. However, we observed a decreased risk of ER+PR+ breast cancer (RR _{<6 vs 8 – 9 h} (95% CI): 0.54 (0.31, 0.93), P for trend, 0.003) with shorter sleep duration.

Conclusions:

Our finding does not support an association between sleep duration and overall breast cancer risk. However, the effect of sleep on different subtypes of breast cancer deserves further investigation.     

Multivitamin use and breast cancer outcomes in women with early-stage breast cancer: the Life After Cancer Epidemiology study

Little is known about the relation of multivitamin use to breast cancer outcomes. 2,236 women diagnosed from 1997 to 2000 with early-stage breast cancer (Stage I ≥ 1 cm, II, or IIIA) were enrolled about 2 years post-diagnosis, primarily from the Kaiser Permanente Northern California Cancer Registry (83%). Multivitamin use pre-diagnosis and post-diagnosis was assessed via mailed questionnaire. Outcomes were ascertained yearly by self-report and verified by medical record review. Delayed-entry Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI), adjusting for sociodemographic, tumor, and lifestyle factors. Overall, 54 and 72% of the cohort reported using multivitamins pre- and post-diagnosis, respectively. A total of 380 recurrences, 212 breast cancer deaths, and 396 total deaths were confirmed. Compared to never use, multivitamin use after diagnosis was not associated with any outcome (recurrence HR = 0.92; 95% CI: 0.71, 1.20; total mortality HR = 0.92; 95% CI: 0.71, 1.19). Compared to never use, persistent use of multivitamins from pre- to post-diagnosis was associated with a non-significant decreased risk of recurrence (HR = 0.76; 95% CI: 0.54, 1.06) and total mortality (HR = 0.79; 95% CI: 0.56, 1.12). The protective associations were limited to women who had been treated by radiation only (P for trend = 0.048 and 0.083 for recurrence and total mortality, respectively) and both radiation and chemotherapy (P for trend = 0.015 and 0.095 for recurrence and total mortality, respectively). In stratified analyses, women who consistently used multivitamins before and after diagnosis and ate more fruits/vegetables (P for trend = 0.008) and were more physically active (P for trend = 0.034) had better overall survival. Multivitamin use along with practice of other health-promoting behaviors may be beneficial in improving breast cancer outcomes in select groups of survivors.     

Postdiagnosis recreational physical activity and breast cancer prognosis: Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

It is important to clarify the associations between modifiable lifestyle factors such as physical activity and breast cancer prognosis to enable the development of evidence-based survivorship recommendations. We performed a systematic review and meta-analyses to summarise the evidence on the relationship between postbreast cancer diagnosis physical activity and mortality, recurrence and second primary cancers. We searched PubMed and Embase through 31st October 2021 and included 20 observational studies and three follow-up observational analyses of patients enrolled in clinical trials. In linear dose-response meta-analysis of the observational studies, each 10-unit increase in metabolic equivalent of task (MET)-h/week higher recreational physical activity was associated with 15% and 14% lower risk of all-cause (95% confidence interval [CI]: 8%-22%, studies = 12, deaths = 3670) and breast cancer-specific mortality (95% CI: 4%-23%, studies = 11, deaths = 1632), respectively. Recreational physical activity was not associated with breast cancer recurrence (HR = 0.97, 95% CI: 0.91-1.05, studies = 6, deaths = 1705). Nonlinear dose-response meta-analyses indicated 48% lower all-cause and 38% lower breast cancer-specific mortality with increasing recreational physical activity up to 20 MET-h/week, but little further reduction in risk at higher levels. Predefined subgroup analyses across strata of body mass index, hormone receptors, adjustment for confounders, number of deaths, menopause and physical activity intensities were consistent in direction and magnitude to the main analyses. Considering the methodological limitations of the included studies, the independent Expert Panel concluded ‘limited-suggestive’ likelihood of causality for an association between recreational physical activity and lower risk of all-cause and breast cancer-specific mortality.     

Racial and ethnic disparities in breast cancer rates by age: NAACCR Breast Cancer Project

Summary Objective. To examine age-specific rates of breast cancer incidence among racial and ethnic groups in the United States.Methods. Subjects were 363,801 women diagnosed with invasive breast cancer diagnosed during 1994–1998 and reported in the North American Association of Central Cancer Registries (NAACCR) data set. Variables analyzed included race, ethnicity, 5-year age group (from 10 years through 85+ years), and stage at time of diagnosis (localized, regional, distant). Incidence rates per 100,000 women were calculated for each 5-year age group and stratified by stage. Rate ratios and 95% confidence intervals were calculated by comparing each racial group with whites and Hispanics with non-Hispanics.Results. Black women experience significantly higher breast cancer incidence up to the age of 40 years and significantly lower incidence after age 50 compared with white women of the same ages. This is called the ‘crossover’ effect. This shifting burden of higher incidence occurs at ages 35–39 for localized stage and at ages 55–59 for regional stage. For distant stage, black women of all ages experience higher incidence compared with white women. Similar crossover effects do not exist for American Indian (AI) or Asian/Pacific Islander (API) women compared with white women. Both AI and API women have significantly lower incidence of breast cancer compared with white women, and Hispanic women have significantly lower incidence compared with non-Hispanic women.Conclusions. This study highlights racial and ethnic differences in breast cancer incidence rates among US women. The crossover effect between black and white women, particularly the lower incidence of localized stage disease diagnosed in older black women, is a significant phenomenon that may be associated with screening practices, and has implications for public health planning and cancer control initiatives to reduce racial/ethnic disparities.     

Postdiagnosis body fatness,weight change and breast cancer prognosis: Global Cancer Update Program (CUP global) systematic literature review and meta-analysis

Previous evidence on postdiagnosis body fatness and mortality after breast cancer was graded as limited-suggestive. To evaluate the evidence on body mass index (BMI), waist circumference, waist-hip-ratio and weight change in relation to breast cancer prognosis, an updated systematic review was conducted. PubMed and Embase were searched for relevant studies published up to 31 October, 2021. Random-effects meta-analyses were conducted to estimate summary relative risks (RRs). The evidence was judged by an independent Expert Panel using pre-defined grading criteria. One randomized controlled trial and 225 observational studies were reviewed (220 publications). There was strong evidence (likelihood of causality: probable) that higher postdiagnosis BMI was associated with increased all-cause mortality (64 studies, 32 507 deaths), breast cancer-specific mortality (39 studies, 14 106 deaths) and second primary breast cancer (11 studies, 5248 events). The respective summary RRs and 95% confidence intervals per 5 kg/m² BMI were 1.07 (1.05-1.10), 1.10 (1.06-1.14) and 1.14 (1.04-1.26), with high between-study heterogeneity (I² = 56%, 60%, 66%), but generally consistent positive associations. Positive associations were also observed for waist circumference, waist-hip-ratio and all-cause and breast cancer-specific mortality. There was limited-suggestive evidence that postdiagnosis BMI was associated with higher risk of recurrence, nonbreast cancer deaths and cardiovascular deaths. The evidence for postdiagnosis (unexplained) weight or BMI change and all outcomes was graded as limited-no conclusion. The RCT showed potential beneficial effect of intentional weight loss on disease-free-survival, but more intervention trials and well-designed observational studies in diverse populations are needed to elucidate the impact of body composition and their changes on breast cancer outcomes.     

UICC Multidisciplinary Project on Breast Cancer: the epidemiology, aetiology and prevention of breast cancer

This report summarizes the conclusions of the 2nd conference of the Multidisciplinary Project on Breast Cancer of the International Union Against Cancer held in 1985. The incidence of breast cancer is rising all over the world and ranges from 0.2-8%/year. There were an estimated 541,000 cases of breast cancer diagnosed in 1975 and over 800,000/year are expected by the year 2000. The increased risk associated with early age at menarche, late age at menopause, late age at 1st birth, and nulliparity suggests the overwhelming importance of ovarian activity in the etiology of breast cancer. No consistent and coherent pattern of endocrine abnormalities associated with breast cancer has been identified, but there is considerable doubt concerning the validity of the concept that estrogen action on the breast is modulated by variations is progesterone secretion. Dietary factors, especially animal fat or meat consumption, are receiving attention. If diet is important, it has to act in childhood or adolescence. The increased risk of breast cancer in women with benign breast disease appears to be restricted to a small proportion of women whose biopsies show atypical hyperplasia. Evidence from a number of recent studies suggests that oral contraceptives (OCs) do not increase the overall risk of breast cancer, although concern has been expressed about numerous subgroups of OC users: women who continue taking OCs around the time of menopause, those who use OCs to delay their 1st pregnancy, and women exposed to prolonged use before age 25 years. Studies of noncontraceptive hormones suggest increased risk occurs only after 10 years or more of use. The prevention of breast cancer was considered in relation to specific agents used as prophylactics in high risk groups and life-style changes. For example, the antiestrogen tamoxifen could be considered for an interventive trial in high-risk women, although problems of toxicity must be considered. Reduction in obesity, especially in postmenopausal women, and a relatively low fat intake are 2 life-style alterations that seem feasible.     

Postdiagnosis diet quality, the combination of diet quality and recreational physical activity, and prognosis after early-stage breast cancer

Objective

To investigate, among women with breast cancer, how postdiagnosis diet quality and the combination of diet quality and recreational physical activity are associated with prognosis.

Methods

This multiethnic, prospective observational cohort included 670 women diagnosed with local or regional breast cancer. Thirty months after diagnosis, women completed self-report assessments on diet and physical activity and were followed for 6 years. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals for death from any cause and breast cancer death.

Results

Women consuming better-quality diets, as defined by higher Healthy Eating Index-2005 scores, had a 60% reduced risk of death from any cause (HR_Q4:Q1: 0.40, 95% CI: 0.17, 0.94) and an 88% reduced risk of death from breast cancer (HR_Q4:Q1: 0.12, 95% CI: 0.02, 0.99). Compared with inactive survivors consuming poor-quality diets, survivors engaging in any recreational physical activity and consuming better-quality diets had an 89% reduced risk of death from any cause (HR: 0.11, 95% CI: 0.04, 0.36) and a 91% reduced risk of death from breast cancer (HR: 0.09, 95% CI: 0.01, 0.89). Associations observed were independent of obesity status.

Conclusion

Women diagnosed with localized or regional breast cancer may improve prognosis by adopting better-quality dietary patterns and regular recreational physical activity. Lifestyle interventions emphasizing postdiagnosis behavior changes are advisable in breast cancer survivors.     

Oral contraceptive use and the prognosis of breast cancer

Summary In 471 breast cancer patients the influence of a positive history of oral contraceptive (OC) use on survival was investigated. 297 (63%) patients used OCs during any period of their life and 92 (20%) used them still at the time of diagnosis. Sixty months after diagnosis OC users had a significantly increased overall survival (p = 0.037). Survival rates amounted to 79.5% and 70.3% for OC users and non-users, respectively. The effect persisted after adjustment for other prognostic factors and was mainly attributed to women who had taken OCs four years or longer (p = 0.025). Comparing the survival after a 56 months median follow-up dependent on duration of OC use (never, 1–48 months, 49 months) in subgroups of prognostic factors, the most significant influence on survival was observed among long-term users with tumors more than 2 cm in diameter (p = 0.005), with axillary node-positive tumors (1–3 nodes, p = 0.055/ 4 nodes, p = 0.019), and with tumors of low estrogen receptor (p = 0.015) or progesterone receptor content (p = 0.04). The difference in survival between OC users and non-users cannot be explained by the distribution of prognostic factors investigated (histological type, histological grade, tumor size, lymph node involvement, hormonal receptor content). OC users had an even higher percentage of poorly differentiated tumors (p = 0.003). These results suggest an effect of OC use on tumor biology during the preclinical phase of the disease.     

Breast cancer prognosis in relation to family history of breast and ovarian cancer

We linked four nationwide Swedish population-based registries to identify first-degree family history of breast and ovarian cancer among breast cancer cases diagnosed between 1991 and 1998 and followed them until death, emigration or end of follow-up in December 1998. The median follow-up was 36 months. Using Cox proportional hazards models, the hazard ratio of death (HR) due to breast cancer was estimated. Women with a family history of breast or ovarian cancer (n=2175, 12.7%) had a nonsignificantly better prognosis than women without any family history, HR 0.86 (95% CI 0.71-1.05); this appeared unrelated to age at diagnosis either in the index case or in relative(s) with breast and/or ovarian cancer. Our study shows that prognostic outlook is not worse among breast cancer patients with family history.     

Clinical subtypes and prognosis of pregnancy-associated breast cancer: results from the Korean Breast Cancer Society Registry database

Purpose

We analyzed the clinicopathologic characteristics and prognosis of pregnancy-associated breast cancer (PABC) according to clinical subtypes to better understand the characteristics of PABC.

Methods

A total of 83,792 female patients between the ages of 20 and 49 were enrolled in the Korean Breast Cancer Society Registry database from January 1, 1996 to December 31, 2015. ‘PABC’ is defined as breast cancer diagnosed during pregnancy or within 1 year after delivery. Other patients were defined as ‘non-PABC’ patients.

Results

In non-PABC patients, luminal A subtype was the most common (50.2%). In PABC patients, TNBC was the most common (40.4%) subtype, while luminal A comprised 21.2% and HER2 subtype comprised 17.3%. There was a significant difference in overall survival (OS). In non-PABC patients, TNBC had the highest HR (HR 2.3, 95% CI 2.1–2.6). In PABC patients, the luminal B subtype (HR+ HER2-high Ki67) had the highest HR at 7.0 (95% CI 1.7–29.1). In multivariate analysis of OS by subtypes, PABC patients had significantly higher HR than non-PABC patients in the HER2 subtype (HR 2.0, 95% CI 1.1–3.7) and luminal B subtype (HR+ HER2-high Ki67) (HR 4.4, 95% CI 1.6–12.3).

Conclusion

PABC showed different biologic features than non-PABC. PABC had a particularly poor prognosis in the luminal B (HR+ HER2-highKi67) and HER2 subtypes. To improve the prognosis of PABC, treatment should be considered according to subtype. Development of drugs that can be used during pregnancy is needed.

     

Prevalence and predictors of antioxidant supplement use during breast cancer treatment

BACKGROUND.

Although many patients take antioxidant dietary supplements during breast cancer treatment, the benefits of such supplementation are unproven. The authors of this report analyzed the prevalence of and factors associated with antioxidant supplement use during breast cancer (BC) treatment among women who participated in the Long Island Breast Cancer Study Project.

METHODS.

From 2002 through 2004, women with BC who had participated a case‐control study from 1996 to 1997 were invited to participate in a follow‐up interview. Antioxidant supplement use was defined as any self‐reported intake of supplemental vitamin C, vitamin E, β‐carotene, or selenium in individual supplements or multivitamins.

RESULTS.

Follow‐up interview participants were younger, more predominantly white, and of higher socioeconomic status than women who did not respond. Among 764 participants who completed the follow‐up interview, 663 (86.8%) reported receiving adjuvant treatment for their BC. Of those 663 women, 401 (60.5%) reported using antioxidants during adjuvant treatment: One hundred twenty of 310 women (38.7%) used antioxidants during chemotherapy, 196 of 464 women (42.2%) used them during radiation, and 286 of 462 women (61.9%) used them during tamoxifen therapy. Of 401 antioxidant users, 278 women (69.3%) used high doses (doses higher than those contained in a Centrum multivitamin). The factors that were associated with high antioxidant supplement use during treatment were higher fruit and vegetable intake at diagnosis (relative risk [RR], 1.71; 95% confidence interval [CI], 1.13‐2.59), tamoxifen use (RR, 3.66; 95% CI, 2.32‐5.78), ever using herbal products (RR, 3.49; 95% CI, 2.26‐5.38), and ever engaging in mind‐body practices (RR, 1.72; 95% CI, 1.13‐2.64).

CONCLUSIONS.

Given the common use of antioxidant supplements during BC treatment, often at high doses and in conjunction with other complementary therapies, future research should address the effects of antioxidant supplementation on BC outcomes. Cancer 2009. © 2009 American Cancer Society.     

Family history of breast cancer and all-cause mortality after breast cancer diagnosis in the Breast Cancer Family Registry

Although having a family history of breast cancer is a well established breast cancer risk factor, it is not known whether it influences mortality after breast cancer diagnosis. We studied 4,153 women with first primary incident invasive breast cancer diagnosed between 1991 and 2000, and enrolled in the Breast Cancer Family Registry through population-based sampling in Northern California, USA; Ontario, Canada; and Melbourne and Sydney, Australia. Cases were oversampled for younger age at diagnosis and/or family history of breast cancer. Carriers of germline mutations in BRCA1 or BRCA2 were excluded. Cases and their relatives completed structured questionnaires assessing breast cancer risk factors and family history of cancer. Cases were followed for a median of 6.5 years, during which 725 deaths occurred. Cox proportional hazards regression was used to evaluate associations between family history of breast cancer at the time of diagnosis and risk of all-cause mortality after breast cancer diagnosis, adjusting for established prognostic factors. The hazard ratios for all-cause mortality were 0.98 (95% confidence interval [CI] = 0.84–1.15) for having at least one first- or second-degree relative with breast cancer, and 0.85 (95% CI = 0.70–1.02) for having at least one first-degree relative with breast cancer, compared with having no such family history. Estimates did not vary appreciably when stratified by case or tumor characteristics. In conclusion, family history of breast cancer is not associated with all-cause mortality after breast cancer diagnosis for women without a known germline mutation in BRCA1 or BRCA2. Therefore, clinical management should not depend on family history of breast cancer.     

IGF1 CA repeat polymorphisms, lifestyle factors and breast cancer risk in the Long Island Breast Cancer Study Project

Insulin-like growth factor I (IGF-I) is an important regulator of growth and differentiation and is a potent mitogen for human breast cancer cells. Recent investigations suggest an association between cytosine-adenine dinucleotide (CA)n repeat polymorphisms of the IGF1 gene and IGF-I levels and further evidence indicates that genotype may influence breast cancer risk. We assessed the relation between IGF1 (CA)n repeats and breast cancer, and evaluated modification of genotype effects according to traditional breast cancer risk factors in 1028 breast cancer cases and 1086 controls. An increased risk of breast cancer was seen for genotypes that included alleles with fewer than (CA)19 repeats when compared to (CA)19 repeat carriers, an association that was particularly strong among premenopausal women [odds ratio (OR)=3.31; 95% confidence interval (CI)=1.47, 7.48]. No significant association was observed between an IGF1 genotype with no (CA)19 repeat compared to (CA)19 repeat genotypes in either pre- or postmenopausal women overall. However, when traditional breast cancer risk factors were considered, premenopausal women with genotypes that lacked a (CA)19 repeat had a nearly 60% increased risk of breast cancer among those who had ever used hormonal birth control, while never users had a significantly reduced risk (Pinteraction=0.01). Among postmenopausal women, those with genotypes lacking a (CA)19 repeat allele had significantly increased breast cancer risk among subjects with a lower than median body mass index (BMI) (OR=1.77 95% CI=1.09, 2.87), while no association for IGF1 genotype was seen among women with a higher than median BMI (Pinteraction=0.04). Our results demonstrate a role for alleles with fewer than (CA)19 repeats as a risk factor for breast cancer and also suggest that several traditional breast cancer risk factors modify the association of the IGF1 (CA)19 repeat genotype.