Supplemental B-Vitamins and Risk of Upper Gastrointestinal Cancers in the Women's Health Initiative

B-vitamins contribute to DNA synthesis, maintenance, and regulation. Few studies have examined associations of supplemental sources of B-vitamins with the incidence of upper gastrointestinal (GI) cancers [including gastric (GCA) and esophageal (ECA) cancers]; the only prior study to comprehensively examine such intakes reported potential elevated risks of ECA. We examined 159,401 postmenopausal women, ages 50-79 years at baseline, including 302 incident GCA and 183 incident ECA cases, over 19 years of follow-up within the Women's Health Initiative observational study and clinic trials. Adjusted Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations of supplemental B-vitamins [riboflavin (B2), pyridoxine (B6), folic acid (B9), or cobalamin (B12)] with GCA and ECA risk, respectively. Although HRs were generally below 1.0, we observed no statistically significant associations between supplemental intakes of any of the evaluated B-vitamins with the risk of GCA or ECA. As the first prospective study to comprehensively assess these associations, our findings do not corroborate prior research indicating potential harm from supplemental B-vitamin intake for upper GI cancer risk. This study adds evidence that supplemental intakes of B-vitamins may be used by postmenopausal women without regard to their relationship with upper GI cancer risk.

Associations Between Changes in Loneliness and Social Connections, and Mental Health During the COVID-19 Pandemic: The Women's Health Initiative

BACKGROUND

Older women have faced significant disruptions in social connections during the coronavirus disease 2019 pandemic. Whether loneliness increased or whether a change in loneliness from pre- to intrapandemic period was associated with mental health during the pandemic is unknown.

METHODS

Older women (n = 27 479; mean age 83.2 [SD: 5.4] years) completed surveys in mid-2020, including questions about loneliness, living arrangements, changes in social connections, and mental health. Loneliness was also previously assessed in 2014-2016. We examined whether loneliness changed from the pre- to intrapandemic period and explored factors associated with this change. In multivariable models, we investigated the association of changes in loneliness and social connections with mental health.

RESULTS

Loneliness increased from pre- to intrapandemic levels. Factors associated with worsening loneliness included older age, experiencing stressful life events, bereavement, histories of vascular disease and depression, and social connection disruptions. Factors associated with a decrease in loneliness included identifying as Black, engaging in more frequent physical activity, being optimistic, and having a higher purpose in life. A 3-point increase in loneliness scores was associated with higher perceived stress, higher depressive, and higher anxiety symptoms. Social connection disruptions showed modest or no associations with mental health.

CONCLUSIONS

Loneliness increased during the pandemic in older women and was associated with higher stress, depressive, and anxiety symptoms. Our findings point to opportunities for interventions targeting lifestyle behaviors, well-being, disrupted social connections, and paying closer attention to those with specific medical and mental health histories that may reduce loneliness and improve mental health.

Effect of Low-Fat Dietary Modification on Incident Open-Angle Glaucoma

PURPOSE

We tested whether dietary modification (DM) altered the risk for incident primary open-angle glaucoma (POAG).

DESIGN

Secondary analysis of a randomized intervention trial.

PARTICIPANTS

We linked Medicare claims data to 45 203 women in the Women's Health Initiative Dietary Modification Trial, of which 23 776 participants were enrolled in fee-for-service Medicare Part B and had physician claims.

METHODS

Women were randomized to follow either DM (a low-fat diet, with increased vegetable, fruit, and grain intake) or their usual diet without modification. Nine thousand three hundred forty women were randomized to the DM intervention, whereas 13 877 women were randomized to the control group. Our analyses were based on an intention-to-treat design, with a follow-up to the end of continuous Medicare coverage, death, or the last clams date (12/31/2018), whichever occurred first. Primary open-angle glaucoma was defined as the first claim with the International Classification of Diseases, Ninth or Tenth Revision, codes. Dietary data were assessed using a food frequency questionnaire.

MAIN OUTCOME MEASURES

We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of POAG. Subgroup analyses were performed with P values for interaction.

RESULTS

After exclusion of women with Medicare-derived glaucoma before randomization, the final analysis included 23 217 women (mean age, 64.4 ± 5.8 years). Baseline characteristics were balanced between the intervention and control groups. Primary open-angle glaucoma incidence was 11.1 per 1000 woman-years (mean follow-up, 11.6 ± 7.4 years; mean DM duration, 5.2 ± 3.2 years). We found no overall benefit of DM in reducing incident POAG (HR, 1.04; 95% CI, 0.96-1.12). Race and participant age did not modify this relation (P = 0.08 and P = 0.24 for interaction, respectively). In further analysis of baseline nutrient and food intake stratified by quartile groups, risk of open-angle glaucoma (OAG) in DM participants in the lowest quartile group for percentage calories (kilocalories) from total fat (33.8 or lower) was increased (HR, 1.22; 95% CI, 1.05-1.41; P = 0.007 for interaction).

CONCLUSIONS

Analysis suggests that DM in participants in the lowest quartile group for percentage calories from total fat at baseline increased the risk of incident OAG among women regardless of age or race.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Lifestyle and Cardiovascular Risk Factors Associated With Heart Failure Subtypes in Postmenopausal Breast Cancer Survivors

Background

Breast cancer (BC) survivors experience an increased burden of long-term comorbidities, including heart failure (HF). However, there is limited understanding of the risk for the development of HF subtypes, such as HF with preserved ejection fraction (HFpEF), in BC survivors.

Objectives

This study sought to estimate the incidence of HFpEF and HF with reduced ejection fraction (HFrEF) in postmenopausal BC survivors and to identify lifestyle and cardiovascular risk factors associated with HF subtypes.

Methods

Within the Women’s Health Initiative, participants with an adjudicated diagnosis of invasive BC were followed to determine the incidence of hospitalized HF, for which adjudication procedures determined left ventricular ejection fraction. We calculated cumulative incidences of HF, HFpEF, and HFrEF. We estimated HRs for risk factors in relation to HF, HFpEF, and HFrEF using Cox proportional hazards survival models.

Results

In 2,272 BC survivors (28.6% Black and 64.9% White), the cumulative incidences of hospitalized HFpEF and HFrEF were 6.68% and 3.96%, respectively, over a median of 7.2 years (IQR: 3.6-12.3 years). For HFpEF, prior myocardial infarction (HR: 2.83; 95% CI: 1.28-6.28), greater waist circumference (HR: 1.99; 95% CI: 1.14-3.49), and smoking history (HR: 1.65; 95% CI: 1.01-2.67) were the strongest risk factors in multivariable models. With the exception of waist circumference, similar patterns were observed for HFrEF, although none were significant. In relation to those without HF, the risk of overall mortality in BC survivors with hospitalized HFpEF was 5.65 (95% CI: 4.11-7.76), and in those with hospitalized HFrEF, it was 3.77 (95% CI: 2.51-5.66).

Conclusions

In this population of older, racially diverse BC survivors, the incidence of HFpEF, as defined by HF hospitalizations, was higher than HFrEF. HF was also associated with an increased mortality risk. Risk factors for HF were largely similar to the general population with the exception of prior myocardial infarction for HFpEF. Notably, both waist circumference and smoking represent potentially modifiable factors.

Abstract 4654: Supplemental one-carbon metabolism related B vitamins and lung cancer risk in the Women's Health Initiative

We and others have reported associations between B vitamins principally involved in one-carbon metabolism and increased lung cancer risk; however results for women have been inconsistent. Here we report on the association of supplemental vitamins B6, folic acid, and B12 intake and lung cancer risk using data from the Women's Health Initiative (WHI) study of postmenopausal women. Between 1993 and 1998, 161,808 women were recruited to participate in the WHI at 40 US clinical centers. After exclusions, 159,232 women were available for analysis and followed prospectively for 18.3 years. Among them, 3,836 incident lung cancer cases were diagnosed. At baseline, supplemental B vitamins from multivitamins, vitamin mixtures, and individual supplements were assessed. Adjusted Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between supplemental B vitamin intake and lung cancer risk. Relative to non-users, women who took ≥50 mg/d of vitamin B6 had 18% (HR 0.82, 95% CI: 0.70-0.97) reduced lung cancer risk. Associations did not differ significantly by smoking status or lung cancer histology. Intakes of folic acid and vitamin B12 were not associated with risk. There is a need for replication of our findings from large, prospective studies with high-quality measurement of supplement intakes. As such, no recommendation can be made at present on the use of B6 supplements for lung cancer prevention in women.

Citation Format: Theodore M. Brasky, Roberta M. Ray, Sandi L. Navarro, Jeannette M. Schenk, Alison M. Newton, Marian L. Neuhouser. Supplemental one-carbon metabolism related B vitamins and lung cancer risk in the Women's Health Initiative [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4654.

Supplemental one-carbon metabolism related B vitamins and lung cancer risk in the Women's Health Initiative

We and others have reported associations between B vitamins principally involved in one-carbon metabolism and increased lung cancer risk; however, results for women have been inconsistent. Here we report on the association of supplemental vitamins B₆ , folic acid and B₁₂ intake and lung cancer risk using data from the Women's Health Initiative (WHI) study of postmenopausal women. Between 1993 and 1998, 161,808 women were recruited to participate in the WHI at 40 clinical centers in the US. After exclusions, 159,232 women were available for analysis and followed prospectively for an average of 18.3 years. Among them, 3,836 incident lung cancer cases were diagnosed. At baseline, supplemental B vitamins from multivitamins, vitamin mixtures and individual supplements were assessed. Adjusted Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between supplemental B vitamin intake and lung cancer risk. Relative to no intake, women who took ≥50 mg/day of vitamin B₆ had 16% (HR 0.84, 95% CI: 0.71-0.99) reduced lung cancer risk. Associations did not differ significantly by smoking status or lung cancer histology. Intakes of folic acid and vitamin B₁₂ were not associated with risk. There is a need for replication of our findings from other large, prospective studies with similar high-quality measurement of supplement intakes before any recommendations can be made at present on B₆ supplementation for lung cancer prevention in women.

Trajectory of recurrent falls in post-menopausal breast cancer survivors and in matched cancer-free controls

PURPOSE

Cross-sectional studies suggest that falls are prevalent among older breast cancer survivors. However, fall risk in this population has not been comprehensively examined. Therefore, we compared fall risk in older women post-breast cancer diagnosis to fall risk before cancer diagnosis and to risk in cancer-free matched controls.

METHODS

Among 2019 women in the Women's Health Initiative with localized breast cancer diagnosed at age ≥ 60 years with fall assessment data for 3 years pre-diagnosis and 3 years post-diagnosis, recurrent fall risk post-diagnosis was compared to risk in 2019 cancer-free controls matched by age, year of WHI entry, and baseline fall frequency. Generalized estimating equations under a logistic regression model were used to compare fall recurrence in breast cancer survivors and controls. Multi-variable models were adjusted for the matching factors, race/ethnicity, body mass index, and multiple chronic conditions.

RESULTS

In breast cancer survivors aged 70.8 years (mean) at diagnosis, over the 3-year pre-diagnosis interval, recurrent falls were reported by 18.5%. Over the 3-year post-diagnosis interval, recurrent falls were reported by 21.8% of breast cancer survivors and 20.0% of controls over the same time period (P = 0.27). Recurrent fall risk did not differ between breast cancer survivors and control women (OR 1.07, 95% CI 0.92-1.25), even after multi-variable adjustment.

CONCLUSIONS

In contrast to prior reports, older breast cancer survivors were not more likely to experience recurrent falls than age-matched counterparts. These findings underscore the need for incorporation of cancer-free control populations in survivorship studies to distinguish cancer sequelae from processes related to aging.

The association of delay in curative intent treatment with survival among breast cancer patients: findings from the Women's Health Initiative

PURPOSE

Delays in adjuvant breast cancer (BC) therapy have been shown to worsen outcomes. However, thus far studies have only evaluated delays to initial treatment, or a particular modality, such as chemotherapy, leaving uncertainty about the role of delay to subsequent therapy and the effects of cumulative delay, on outcomes. We investigated the associations of delays across treatment modalities with survival.

METHODS

We included 3368 women with incident stage I-III BC in the Women's Health Initiative (WHI) enrolled in fee-for-service Medicare who underwent definitive surgery. This prospective analysis characterized treatment delays by linking WHI study records to Medicare claims. Delays were defined as > 8 weeks to surgery, chemotherapy, and radiation from diagnosis or prior treatment. We used Cox proportional hazards models to estimate BC-specific mortality (BCSM) and all-cause mortality (ACM) in relation to treatment delays.

RESULTS

We found 21.8% of women experienced delay to at least one therapy modality. In adjusted analysis, delay to chemotherapy was associated with a higher risk of BCSM (HR = 1.71; 95% CI 1.07-2.75) and ACM (HR = 1.39; 95% CI 1.02-1.90); delay in radiation increased BCSM risk (HR = 1.49; 95% CI 1.00-2.21) but not ACM risk (HR = 1.19; 95% CI 0.99-1.42). Delays across multiple treatment modalities increased BCSM risk threefold (95% CI 1.51-6.12) and ACM risk 2.3-fold (95% CI 1.50-3.50).

CONCLUSIONS

A delay to a single treatment modality and delay to a greater extent an accumulation of delays were associated with higher BCSM and ACM after BC. Timely care throughout the continuum of breast cancer treatment is important for optimal outcomes.

Occupational exposures and parkinsonism among Shanghai women textile workers

BACKGROUND

Endotoxin, a contaminant of cotton dust, is an experimental model for parkinsonism (PS).

METHODS

We investigated associations between exposures to endotoxin, solvents, magnetic fields, and night shift work, and neurologist-determined PS among Shanghai women textile workers, including 537 retired cotton factory workers ages ≥50 years and an age-matched reference group of 286 retired textile workers not exposed to cotton dust. Repeat exams were conducted 2.5 years after enrollment among 467 cotton workers and 229 reference workers.

RESULTS

We identified 39 prevalent PS cases and 784 non-cases. No consistent or statistically significant associations were observed for endotoxin, solvents, magnetic fields, or shift work with PS risk, severity, or progression.

CONCLUSIONS

Despite the null findings, additional studies of endotoxin exposure and risk of PS in other well-characterized occupational cohorts are warranted in view of toxicological evidence that endotoxin is a pathogenic agent and its widespread occurrence in multiple industries worldwide.

Racial Differences in the Effects of Hormone Therapy on Incident Open-Angle Glaucoma in a Randomized Trial

PURPOSE

We conducted a secondary analysis of a randomized, placebo-controlled trial to test if hormone therapy (HT) altered the risk of open-angle glaucoma (OAG), and if the risk reduction varied by race.

DESIGN

Secondary analysis of randomized controlled trial data.

METHODS

We linked Medicare claims data to 25 535 women in the Women's Health Initiative. Women without a uterus were randomized to receive either oral conjugated equine estrogens (CEE 0.625 mg/day) or placebo, and women with a uterus received oral CEE and medroxyprogesterone acetate (CEE 0.625 mg/day + MPA 2.5 mg/day) or placebo. We used Cox proportional hazards models to calculate hazard ratios (HR) and 95% confidence interval.

RESULTS

After exclusion of women with prevalent glaucoma or without claims for eye care provider visits, the final analysis included 8102 women (mean age = 68.5 ± 4.8 years). The OAG incidence was 7.6% (mean follow-up = 11.5 ± 5.2 years; mean HT duration = 4.4 ± 2.3 years). Increased age (P trend = .01) and African-American race (HR = 2.69, 95% CI = 2.13-3.42; white as a reference) were significant risk factors for incident OAG. We found no overall benefit of HT in reducing incident OAG (HR = 1.01, 95% CI = 0.79-1.29 in the CEE trial, and HR = 1.05, 95% CI = 0.85-1.29 in the CEE + MPA trial). However, race modified the relationship between CEE use and OAG risk (P interaction = .01), and risk was reduced in African-American women treated with CEE (HR = 0.49, 95% CI = 0.27-0.88), compared to placebo. Race did not modify the relation between CEE + MPA use and OAG risk (P interaction = .68).

CONCLUSIONS

Analysis suggests that HT containing estrogen, but not a combination of estrogen and progesterone, reduces the risk of incident OAG among African-American women. Further investigation is needed.

The Women's Health Initiative (WHI) Life and Longevity After Cancer (LILAC) Study: Description and Baseline Characteristics of Participants

Background: The Women's Health Initiative (WHI) Life and Longevity After Cancer (LILAC) study offers an important opportunity to advance cancer research by extending the original WHI studies to examine survivorship in women diagnosed with cancer during their participation in WHI.Methods: The goals of LILAC are to (i) obtain cancer treatment information and long-term cancer outcomes for women diagnosed with one of eight selected cancers (breast, endometrial, ovarian, lung, and colorectal cancers, and melanoma, lymphoma, and leukemia); (ii) augment the existing WHI biorepository with fixed tumor tissue from the solid tumor sites for cancers diagnosed since 2002; and (iii) develop, refine, and validate methods to use administrative data to capture treatment and recurrence data. Methods for accomplishing these goals are described, as are results from the initial LILAC participant survey.Results: A total of 9,934 WHI participants living with cancer were eligible for LILAC participation, of which 78% (N = 7,760) agreed to participate. Among the three most prevalent cancer types, 54% are breast cancer survivors, 11% are melanoma survivors, and 10% are survivors of colorectal cancer.Conclusions: In addition to describing this resource, we present pertinent lessons that may assist other investigators interested in embedding survivorship research into existing large epidemiologic cohorts.Impact: The LILAC resource offers a valuable opportunity for researchers to study cancer survivorship and issues pertinent to cancer survivors in future studies. Cancer Epidemiol Biomarkers Prev; 27(2); 125-37. ©2017 AACR.

Factors Associated With New-Onset Depression Following Ischemic Stroke: The Women's Health Initiative

BACKGROUND

Psychosocial characteristics have a strong effect on risk of depression, and their direct treatment with behavioral interventions reduces rates of depression. Because new-onset poststroke depression (NPSD) is frequent, devastating, and often treatment-resistant, novel preventive efforts are needed. As a first step toward developing behavioral interventions for NPSD, we investigated whether prestroke psychosocial factors influenced rates of NPSD in a manner similar to the general population.

METHODS AND RESULTS

Using the Women's Health Initiative, we analyzed 1424 respondents who were stroke-free at enrollment and had no self-reported history of depression from enrollment to their nonfatal ischemic stroke based on initiation of treatment for depression or the Burnam screening instrument for detecting depressive disorders. NPSD was assessed using the same method during the 5-year poststroke period. Logistic regression provided odds ratios of NPSD controlling for multiple covariates. NPSD occurred in 21.4% (305/1424) of the analytic cohort and varied by stroke severity as measured by the Glasgow scale, ranging from 16.7% of those with good recovery to 31.6% of those severely disabled. Women with total anterior circulation infarction had the highest level (31.4%) of NPSD while those with lacunar infarction had the lowest (16.1%). Prestroke psychosocial measures had different associations with NPSD depending on functional recovery of the individual.

CONCLUSIONS

There is a difference in the relationship of prestroke psychosocial status and risk of NPSD depending on stroke severity; thus it may be that the same preventive interventions might not work for all stroke patients. One size does not fit all.

A Randomized Trial of a Low-Fat Diet Intervention on Blood Pressure and Hypertension: Tertiary Analysis of the WHI Dietary Modification Trial

BACKGROUND

This post hoc analysis determined if the Women's Health Initiative (WHI) Diet Modification intervention (DM-I) resulted in a significantly different rate of incident hypertension (HTN), as well as longitudinal changes in blood pressure.

METHODS

Participants were 48,835 postmenopausal women aged 50-79 years who were randomly assigned to either the intervention or comparison group. HTN was defined as self-report of treated HTN collected semiannually or blood pressure ≥140/90mm Hg at one of the annual follow-up clinic visits.

RESULTS

After a mean follow-up of 8.3 years, and among those who did not have HTN at baseline (n = 31,146), there were 16,174 (51.9%) HTN cases and those assigned to the intervention group had a 4% lower overall risk of developing incident HTN (hazard ratio (HR): 0.96, 95% confidence interval (CI): 0.93-0.99). Although the risk of HTN was lower in the DM-I group in the first few years, the HR became greater than 1 after year 5 (P-trend < 0.01). Similarly, randomization to the DM-I arm resulted in a small but significantly lower average systolic blood pressure (SBP) at 1 year of follow-up (-0.66mm Hg, 0.44-0.89) that increased over the following 8 years (0.16mm Hg/year, 0.11-0.21), such that any early benefit was eliminated by year 5 and a minimal deleterious effect emerged by year 7.

CONCLUSION

Randomization to an intensive behavioral dietary modification program aimed at a lower total fat intake is not associated with sustained reductions in blood pressure or risk of HTN in postmenopausal women.

CLINICAL TRIAL REGISTRATION

url http://www.clinicaltrials.gov, unique identifier nct00000611.

Association of Baseline Depressive Symptoms with Prevalent and Incident Pre-Hypertension and Hypertension in Postmenopausal Hispanic Women: Results from the Women's Health Initiative

BACKGROUND

Depression and depressive symptoms are risk factors for hypertension (HTN) and cardiovascular disease (CVD). Hispanic women have higher rates of depressive symptoms compared to other racial/ethnic groups yet few studies have investigated its association with incident prehypertension and hypertension among postmenopausal Hispanic women. This study aims to assess if an association exists between baseline depression and incident hypertension at 3 years follow-up among postmenopausal Hispanic women.

METHODS

Prospective cohort study, Women's Health Initiative (WHI), included 4,680 Hispanic women who participated in the observational and clinical trial studies at baseline and at third-year follow-up. Baseline current depressive symptoms and past depression history were measured as well as important correlates of depression-social support, optimism, life events and caregiving. Multinomial logistic regression was used to estimate prevalent and incident prehypertension and hypertension in relation to depressive symptoms.

RESULTS

Prevalence of current baseline depression ranged from 26% to 28% by hypertension category and education moderated these rates. In age-adjusted models, women with depression were more likely to be hypertensive (OR = 1.25; 95% CI 1.04-1.51), although results were attenuated when adjusting for covariates. Depression at baseline in normotensive Hispanic women was associated with incident hypertension at year 3 follow-up (OR = 1.74; 95% CI 1.10-2.74) after adjustment for insurance and behavioral factors. However, further adjustment for clinical covariates attenuated the association. Analyses of psychosocial variables correlated with depression but did not alter findings. Low rates of antidepressant medication usage were also reported.

CONCLUSIONS

In the largest longitudinal study to date of older Hispanic women which included physiologic, behavioral and psychosocial moderators of depression, there was no association between baseline depressive symptoms and prevalent nor incident pre-hypertension and hypertension. We found low rates of antidepressant medication usage among Hispanic women suggesting a possible point for clinical intervention.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00000611.

Medication use trajectories of postmenopausal breast cancer survivors and matched cancer-free controls

While adverse medical sequelae are associated with breast cancer therapies, information on breast cancer impact on medication use is limited. Therefore, we compared medication use before and after diagnosis of early stage breast cancer to medication use in matched, cancer-free controls. Of 68,132 Women's Health Initiative participants, 3726 were diagnosed with breast cancer and, after exclusions, in 1731 breast cancer cases, medication use before and >3 years after diagnosis (mean 5.3 ± 2.1 SD) was compared to use in 1731 cancer-free matched controls on similar inventory dates. The medication category number at follow-up inventory was the primary study outcome. Medication category use (n, mean, SD) was comparable at baseline and significantly increased at follow-up in both cases (2.48 ± 1.66 vs. 4.15 ± 2.13, baseline vs follow-up, respectively, P < .0001) and controls (2.44 ± 1.67 vs. 3.95 ± 2.13, respectively, P < .0001), with clinically marginal but statistically significant additional medication category use by cases (0.20 ± 2.40, P < .0001). Tamoxifen users used somewhat more selected medication categories at follow-up assessment (mean 3.40 ± 1.89 vs. 3.21 ± 1.99, respectively, P = 0.05), while aromatase inhibitor users used more medication categories (mean 4.85 ± 2.10 vs. 4.44 ± 1.94, respectively, P = 0.02). No increase in medication category was seen in cases who were not current endocrine therapy users. Breast cancer survivors having only a clinically marginal increase in medication use compared to cancer-free controls. These findings highlight the importance of incorporation of control populations in studies of cancer survivorship.

Plasma equol concentration is not associated with breast cancer and fibrocystic breast conditions among women in Shanghai, China

Equol (a bacterial metabolite of the soy isoflavone daidzein) is produced by 30% to 50% of humans and may be associated with health outcomes. We hypothesized that plasma equol would be inversely associated with risks of fibrocystic breast conditions (FBC) and breast cancer (BC). Plasma from women in a breast self-examination trial in Shanghai with BC (n=269) or FBC (n=443), and age-matched controls (n=1027) was analyzed for isoflavones. Equol was grouped into categories (<20, 20-<45, and ≥45nmol/L) and, among women with daidzein ≥20nmol/L, the log10 equol:daidzein ratio was grouped into tertiles. Where available, non-cancerous tissue (NCT) adjacent to the carcinomas from women with BC were classified as non-proliferative or proliferative (n=130 and 172, respectively). The lesions from women with FBC were similarly classified (n=99 and 92, respectively). Odds ratios (OR) and 95% confidence intervals (CI) were calculated across equol categories and tertiles of log10 equol:daidzein ratio. Equol categories were not associated with FBC or BC (P>.05). For log10 equol:daidzein, compared to controls there were positive associations in the mid tertile for proliferative FBC (OR 2.06, 95% CI 1.08-3.93), BC with proliferative NCT (OR 2.95, 95% CI 1.37-6.35), and all BC regardless of histology (OR 2.37, 95% CI 1.43-3.95). However, trends in ORs with increasing plasma equol values or equol:daidzein ratios were not observed (P>.05). The results of this study do not provide evidence that equol plays a role in the etiology of these breast conditions. However, further work is needed to confirm or refute this conclusion.

Abstract 111: Factors Associated With New-onset Depression Following Ischemic Stroke: Results From the Women’s Health Initiative

Background: Although poststroke depression is a common and devastating consequence of stroke, few studies have examined the occurrence and correlates of developing depression among stroke survivors without a history of depression before the stroke.

Hypothesis: Using data on post-menopausal women from the Women’s Health Initiative (WHI), we estimated the odds of new-onset depression poststroke (NDPS) and assessed the associations of psychosocial and other factors with NDPS.

Methods: We analyzed data from 1433 respondents who were stroke-free at enrollment and had no self-reported history of depression prior to their non-fatal ischemic stroke, and had information regarding stroke severity. NDPS was assessed in the five-year period after stroke using the Center for Epidemiologic Studies Depression Scale or new antidepressant medication use. Unadjusted 5-year depression rates are presented by demographic, comorbid, and psychosocial factors measured pre-stroke. Vascular territory of stroke is given by the Oxfordshire classification. Logistic regression provided odds ratios of NDPS controlling for multiple covariates.

Results: New-onset depression post ischemic stroke occurred in 21.4% (306/1433) of the analytic cohort and varied by stroke outcome as measured by the Glasgow scale ranging from 16.7% of those with good recovery to 31.5% of those severely disabled. Women with total anterior circulation infarction had the highest level (45.8%) of NDPS while those with lacunar infarction had the lowest (19.1%). Among those with ischemic stroke and good recovery (n=754), moderate level of optimism was associated with a reduced odds of NDPS (compared to low optimism, OR, 0.29; 95%CI, 0.14-0.63) adjusting for demographics, behavioral factors, and comorbidities. Cynical hostility, social support, and traumatic life events were unassociated with NDPS.

Conclusions: New-onset depression is common after ischemic stroke among post-menopausal women. Though rarely studied in poststroke depression, psychosocial factors (specifically optimism) may play a role in reducing risk for new-onset depression after stroke.

Insecticide exposure and farm history in relation to risk of lymphomas and leukemias in the Women's Health Initiative observational study cohort

PURPOSE

Relationships of farm history and insecticide exposure at home or work with lymphohematopoietic (LH) neoplasm risk were investigated in a large prospective cohort of US women.

METHODS

In questionnaires, women self-reported history living or working on a farm, personally mixing or applying insecticides, insecticide application in the home or workplace by a commercial service, and treating pets with insecticides. Relationships with non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, plasma cell neoplasms, and myeloid leukemia were investigated using Cox proportional hazard models. Age and farming history were explored as effect modifiers.

RESULTS

The analysis included 76,493 women and 822 NHL cases. Women who ever lived or worked on a farm had 1.12 times the risk of NHL (95% confidence interval [CI] = 0.95-1.32) compared to those who did not. Women who reported that a commercial service ever applied insecticides in their immediate surroundings had 65% higher risk of CLL/SLL (95% CI = 1.15-2.38). Women aged less than 65 years who ever applied insecticides had 87% higher risk of DLBCL (95% CI = 1.13-3.09).

CONCLUSIONS

Insecticide exposures may contribute to risk of CLL/SLL and DLBCL. Future studies should examine relationships of LH subtypes with specific types of household insecticides.

Occupational exposures and risk of stomach and esophageal cancers: update of a cohort of female textile workers in Shanghai, China

BACKGROUND

Associations between stomach and esophageal cancer and exposures to dusts, metals, chemicals, and endotoxin in the workplace are not very well understood, particularly in women.

METHODS

We followed 267,400 female textile workers in Shanghai, China for cancer incidence from 1989 to 2006. Stomach (n = 1374) and esophageal (n = 190) cancer cases were identified and a comparison subcohort (n = 3187) was randomly selected. Cox proportional hazard modeling was used, adjusting for age and smoking.

RESULTS

Increasing stomach cancer risk was observed with increasing duration of synthetic fiber dust exposure (p = 0.03), although the magnitude of effect was small (20 + years: HR = 1.2, 95% CI 1.1-1.4). Trends with endotoxin exposure were modestly inversed for esophageal cancer and increased for stomach cancer, but with little deviation from a null association.

CONCLUSIONS

Our findings demonstrate that long durations of synthetic fiber dust exposure can increase stomach cancer risk in women, but provide limited support for associations with other textile industry exposures.

Mammography interval and breast cancer mortality in women over the age of 75

The purpose of this study is to evaluate the relationship between mammography interval and breast cancer mortality among older women with breast cancer. The study population included 1,914 women diagnosed with invasive breast cancer at age 75 or later during their participation in the Women's health initiative, with an average follow-up of 4.4 years (3.1 SD). Cause of death was based on medical record review. Mammography interval was defined as the time between the last self-reported mammogram 7 or more months prior to diagnosis, and the date of diagnosis. Multivariable adjusted hazard ratios (HR) and 95 % confidence intervals (CIs) for breast cancer mortality and all-cause mortality were computed from Cox proportional hazards analyses. Prior mammograms were reported by 73.0 % of women from 7 months to ≤2 year of diagnosis (referent group), 19.4 % (>2 to <5 years), and 7.5 % (≥5 years or no prior mammogram). Women with the longest versus shortest intervals had more poorly differentiated (28.5 % vs. 22.7 %), advanced stage (25.7 % vs. 22.9 %), and estrogen receptor negative tumors (20.9 % vs. 13.1 %). Compared to the referent group, women with intervals of >2 to <5 years or ≥5 years had an increased risk of breast cancer mortality (HR 1.62, 95 % CI 1.03-2.54) and (HR 2.80, 95 % CI 1.57-5.00), respectively, p trend = 0.0002. There was no significant relationship between mammography interval and other causes of death. These results suggest a continued role for screening mammography among women 75 years of age and older.

Potency of progestogens used in hormonal therapy: toward understanding differential actions

Progestogens are widely used in contraception and in hormone therapy. Biochemical and molecular biological evidence suggests that progestogens differ widely in their affinities and transcriptional effects via different steroid receptors, and hence cannot be considered as a single class of compounds. Consistent with these observations, recent clinical evidence suggests that, despite their similar progestogenic actions, these differences underlie different side-effect profiles for cardiovascular disease and susceptibility to infectious diseases. However, choice of progestogen for maximal benefit and minimal side-effects is hampered by insufficient comparative clinical and molecular studies to understand their relative mechanisms of action, as well as their relative potencies for different assays and clinical effects. This review evaluates the usage, meaning and significance of the terms affinity, potency and efficacy in different models systems, with a view to improved understanding of their physiological and pharmacological significance. This article is part of a Special Issue entitled 'Menopause'.

Prevalence and incident prehypertension and hypertension in postmenopausal Hispanic women: results from the Women's Health Initiative

BACKGROUND

There is a paucity of research on prehypertension and incident hypertension among postmenopausal Hispanic women. The overall objective is to determine the multiple risk factors associated with the prevalence of hypertension status at baseline and incident hypertension at year 3 in postmenopausal Hispanic women.

METHODS

For the analyses in this paper, we included a total of 4,680 Hispanic women who participated in the Women's Health Initiative (WHI), a randomized clinical trial and observational study, at baseline (1994-1998) and at third-year follow-up and for whom blood pressure was measured at year 3 (n = 3,848). Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of hypertension status, defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg, to assess the odds of incident hypertension at year 3 of follow-up in association with the factors included in the baseline models.

RESULTS

At year 3 of follow-up, 27.3% of Hispanic women who were normotensive at baseline had progressed to prehypertension, and 9.0% had become hypertensive. Among the prehypertensive participants at baseline, 30.4% had progressed to hypertension. Compared with normotensive Hispanic women, hypertensive participants had a higher number of cardiovascular risk factors: body mass index ≥30 kg/m(2) (OR = 3.76; 95% CI = 3.01-4.71), a family history of diabetes, stroke, and/or myocardial infarction (OR = 1.12; 95% CI 1.03-1.23), treated hypercholesterolemia (OR = 1.57; 95% CI = 1.23-1.99), treated diabetes (OR = 2.04; 95% CI = 1.40-2.97), and a history of cardiovascular disease (OR = 2.04; 95% CI = 1.58-2.64).

CONCLUSIONS

Hispanic women seem to experience an increased risk of incident hypertension in later adulthood. On a practical level, recommendations for preventive care and population-wide adoption of health behaviors, such as community-focused campaigns to engage in physical activity, may contribute to reductions in hypertension risk factors.

CLINICAL TRIALS REGISTRATION

Trial Number NCT00000611.

Use of Medicare data to identify coronary heart disease outcomes in the Women's Health Initiative

BACKGROUND

Data collected as part of routine clinical practice could be used to detect cardiovascular outcomes in pragmatic clinical trials or clinical registry studies. The reliability of claims data for documenting outcomes is unknown.

METHODS AND RESULTS

We linked records of Women's Health Initiative (WHI) participants aged ≥65 years to Medicare claims data and compared hospitalizations that had diagnosis codes for acute myocardial infarction or coronary revascularization with WHI outcomes adjudicated by study physicians. We then compared the hazard ratios for active versus placebo hormone therapy based solely on WHI-adjudicated events with corresponding hazard ratios based solely on claims data for the same hormone trial participants. Agreement between WHI-adjudicated outcomes and Medicare claims was good for the diagnosis of myocardial infarction (κ, 0.71-0.74) and excellent for coronary revascularization (κ, 0.88-0.91). The hormone:placebo hazard ratio for clinical myocardial infarction was 1.31 (95% confidence interval, 1.03-1.67) based on WHI outcomes and 1.29 (95% confidence interval, 1.00-1.68) based on Medicare data. The hazard ratio for coronary revascularization was 1.09 (95% confidence interval, 0.88-1.35) based on WHI outcomes and 1.10 (95% confidence interval, 0.89-1.35) based on Medicare data. The differences between hazard ratios derived from WHI and Medicare data were not significant in 1000 bootstrap replications.

CONCLUSIONS

Medicare claims may provide useful data on coronary heart disease outcomes among patients aged ≥65 years in clinical research studies.

CLINICAL TRIALS REGISTRATION INFORMATION

URL: www.clinicaltrials.gov. Unique identifier: NCT00000611.

Occupational exposure to magnetic fields and breast cancer among women textile workers in Shanghai, China

Exposure to magnetic fields (MFs) is hypothesized to increase the risk of breast cancer by reducing production of melatonin by the pineal gland. A nested case-cohort study was conducted to investigate the association between occupational exposure to MFs and the risk of breast cancer within a cohort of 267,400 female textile workers in Shanghai, China. The study included 1,687 incident breast cancer cases diagnosed from 1989 to 2000 and 4,702 noncases selected from the cohort. Subjects' complete work histories were linked to a job-exposure matrix developed specifically for the present study to estimate cumulative MF exposure. Hazard ratios and 95% confidence intervals were calculated using Cox proportional hazards modeling that was adapted for the case-cohort design. Hazard ratios were estimated in relation to cumulative exposure during a woman's entire working years. No association was observed between cumulative exposure to MFs and overall risk of breast cancer. The hazard ratio for the highest compared with the lowest quartile of cumulative exposure was 1.03 (95% confidence interval: 0.87, 1.21). Similar null findings were observed when exposures were lagged and stratified by age at breast cancer diagnosis. The findings do not support the hypothesis that MF exposure increases the risk of breast cancer.

Evidence of a paradoxical relationship between endotoxin and lung cancer after accounting for left truncation in a study of Chinese female textile workers

INTRODUCTION

Occupational exposure to endotoxin, found in Gram-negative bacteria in organic material, has been associated predominantly with a reduced risk of lung cancer among workers. An inverse exposure-response gradient among women textile workers in Shanghai, China, has been reported previously. In this case-cohort study, we investigated the influence of left truncation, which can itself induce a downward trend, on the observed association.

METHODS

Subjects were enrolled between 1989 and 1991 and followed until 1998. The data were left-truncated as all subjects were hired before baseline. An analysis was performed with 3038 subcohort members and 602 cases of incident lung cancer. To evaluate left truncation, we compared lung cancer rates in those hired longer ago with those hired more recently among unexposed subjects. Cox proportional hazards modelling was used to estimate incident rate ratios (IRRs) and 95% CIs.

RESULTS

Among those who were never exposed to workplace endotoxin, we compared lung cancer rates in those hired >35 years before enrolment with workers hired ≤35 years before enrolment and observed a reduced risk in the former group, IRR=0.74, 95% CI (0.51 to 1.07). After accounting for this downward bias from left truncation, the reduced risk associated with endotoxin remained among those hired ≤50 years before enrolment. In contrast, there was suggestion of an increased risk of lung cancer among those hired >50 years ago.

CONCLUSIONS

After examination of left truncation bias, an inverse dose-response between endotoxin and lung cancer remained for all subjects except those hired longest ago.

Abstract 157: Mammography interval and breast cancer mortality in the Women's Health Initiative

Background: The 2009 U.S. Preventive Services Task Force (USPSTF) statement on screening for breast cancer suggests the lack of evidence for mammography for women 75 years or older based on the premise that disease would be indolent at advanced age. Analysis of the Women's Health Initiative (WHI) data refute this hypothesis, in that over 60% of breast cancers diagnosed between ages 70 to 79 were moderately or poorly differentiated. In order to better understand the role of screening mammography in older women, we evaluated the relationship between the time interval from breast cancer diagnosis to the last prior mammogram, and mortality due to breast cancer in the WHI. Methods: The study sample included 8,663 women enrolled in the WHI observational study (OS) or clinical trial (CT) who were diagnosed with breast cancer over an average of 12.2 (2.6 SD) years of follow-up (1,670 with insitu disease). Information on mammography was obtained annually or semi-annually from medical record update forms. Mammography interval was defined as the time between the date of diagnosis, and the last self- reported mammogram completed &gt; 6 months prior to diagnosis. Self- and interviewer-administered questionnaires were used to collect information on other risk factors. Cox proportional hazards regression was used to analyze the association between mammography interval and breast cancer mortality stratified by age at diagnosis (50-74 vs 75+). Statistical tests were two-sided. Results: Prior mammograms were reported by 30% of women within &gt; 6 months to &lt; 1 year of diagnosis, 47% between 1 to &lt; 2 years, 17.2% between 2 to 5 years and 5.8 % at &gt; 5 years, or none at all. Longer interval was associated with advanced stage with 23% of women who had an interval of &gt; 5 years diagnosed with regional or distant disease, compared to 20% of women with an interval of &gt; 6 months to &lt; 1 year, p=0.05. Women with a longer interval were also more likely to have estrogen receptor negative disease (22% vs 16%, p=0.03). In a model adjusted for age, race/ethnicity, OS or CT, health insurance, marital status, Charlson co-morbidity index, and body mass index, longer mammography interval as compared to an interval of &gt; 6 months to &lt; 1 year (referent), was significantly associated with increased breast cancer mortality for women &gt; age 75 at diagnosis. A significant association was not seen for women age 50 to 74. For women &gt; age 75, an interval of &gt; 2 to &lt; 5 years resulted in a hazard ratio (HR) of death from breast cancer of 1.87 (95% CI, 1.10 to 3.19), and an interval of &gt; 5 years or no mammogram, resulted in a HR of 3.17 (95% CI, 1.68-5.96), p-trend 0.0001. For women age 50-74, the respective HR's and 95% CI were 1.05 (0.75-1.46) and 1.28 (0.8-2.06), p-trend 0.43. Conclusions: Extended time between breast cancer diagnosis and the last mammogram had a significant impact on breast cancer mortality for women diagnosed after age 75, suggesting a role for continued screening to reduce breast cancer mortality in older women.

Citation Format: Michael S. Simon, Sylvia Wassertheil-Smoller, Cynthia A. Thompson, Roberta M. Ray, F Allan Hubell, Dorothy Lane, Lawrence Lessin, Hema Vankayala, Lew Kuller. Mammography interval and breast cancer mortality in the Women's Health Initiative. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 157. doi:10.1158/1538-7445.AM2013-157

Reproductive factors and risk of lung cancer in female textile workers in Shanghai, China

PURPOSE

Hormonal factors may play a role in the development of lung cancer in women. This study examined the relationship between lung cancer and reproductive factors in a large cohort of women, most of whom never smoked (97%).

METHODS

A cohort of 267,400 female textile workers in Shanghai, China, enrolled in a trial of breast self-examination provided information on reproductive history, demographical factors, and cigarette smoking at enrollment in 1989-91. The cohort was followed until July of 2000 for incidence of lung cancer; 824 cases were identified. Hazard ratios (HR) and 95% confidence intervals (CI) associated with selected reproductive factors were calculated using Cox proportional hazards modeling, adjusting for smoking, age, and also parity when relevant.

RESULTS

Nulliparous women were at increased risk compared to parous women (HR = 1.33, 95% CI 1.00-1.77). Women who had gone through menopause at baseline were at increased risk compared to women of the same age who were still menstruating. Risk was higher in women with a surgical menopause (HR = 1.64, 95% CI 0.96-2.79) than in those with a natural menopause (HR = 1.35, 95% CI 0.84-2.18), and risk was highest in those postmenopausal women with a hysterectomy and bilateral oophorectomy at baseline (HR = 1.39, 95% CI 0.96-2.00), although the risk estimates were not statistically significant.

CONCLUSIONS

These results support experimental data that demonstrate a biological role for hormones in lung carcinogenesis.

B vitamin intakes and incidence of colorectal cancer: results from the Women's Health Initiative Observational Study cohort

BACKGROUND

The role of one-carbon metabolism nutrients in colorectal carcinogenesis is not fully understood. Associations might be modified by mandated folic acid (FA) fortification or alcohol intake.

OBJECTIVE

We investigated associations between intakes of folate, riboflavin, vitamin B-6, and vitamin B-12 and colorectal cancer (CRC) in the Women's Health Initiative Observational Study, stratified by time exposed to FA fortification and alcohol intake.

DESIGN

A total of 88,045 postmenopausal women were recruited during 1993-1998; 1003 incident CRC cases were ascertained as of 2009. Quartiles of dietary intakes were compared; HRs and 95% CIs were estimated by Cox proportional hazards models.

RESULTS

Dietary and total intakes of vitamin B-6 in quartile 4 compared with quartile 1 (HR: 0.80; 95% CI: 0.66, 0.97 and HR: 0.80; 95% CI: 0.66, 0.99, respectively) and total intakes of riboflavin (HR: 0.81; 95% CI: 0.66, 0.99) were associated with reduced risk of CRC overall and of regionally spread disease. In current drinkers who consumed <1 drink (13 g alcohol)/wk, B vitamin intakes were inversely associated with CRC risk (P-interaction < 0.05). Dietary folate intake was positively associated with CRC risk among women who had experienced the initiation of FA fortification for 3 to <9 y (P-interaction < 0.01).

CONCLUSIONS

Vitamin B-6 and riboflavin intakes from diet and supplements were associated with a decreased risk of CRC in postmenopausal women. Associations of B vitamin intake were particularly strong for regional disease and among women drinkers who consumed alcohol infrequently. Our study provides new evidence that the increased folate intake during the early postfortification period may have been associated with a transient increase in CRC risk.

Occupational exposures and mortality from cardiovascular disease among women textile workers in Shanghai, China

BACKGROUND

Exposure to textile fiber dusts, like particulate air pollution, may be associated with cardiovascular disease (CVD) mortality. Bacterial endotoxin, a potent inflammagen found in cotton dust, may be a specific risk factor.

METHODS

Female textile workers (N = 267,400) in Shanghai, China were followed for CVD mortality (1989-2000). Factory exposures were approximated by sector classifications based on materials and processes. Quantitative endotoxin and cotton dust measures were available for a subcohort (n = 3,188). Cox proportional hazards modeling was used to estimate hazard ratios (HR) and 95% confidence interval (CI).

RESULTS

Slightly elevated mortality risk for the cotton sector was seen for ischemic stroke (HR = 1.12, 95% CI: 0.97-1.31) and hemorrhagic stroke (HR = 1.12, 95% CI: 1.02-1.23). Similar hemorrhagic stroke mortality risk was observed in high dust sectors (HR = 1.12, 95% CI: 1.02-1.24). No association was observed for ischemic heart disease.

CONCLUSIONS

Exposures in textile factories may have contributed to CVD mortality among this cohort. The specific components of these exposures that may be harmful are not clear and should be further investigated.

A prospective study of serum 25-hydroxyvitamin D levels, blood pressure, and incident hypertension in postmenopausal women

In randomized trials, the effect of vitamin D supplementation on blood pressure has been equivocal, while most prospective cohort studies have shown that the risk of incident hypertension is lower in people with higher levels of 25-hydroxyvitamin D (25(OH)D). The authors examined the association between levels of 25(OH)D and changes in blood pressure and incident hypertension in 4,863 postmenopausal women recruited into the Women's Health Initiative between 1993 and 1998. Over 7 years, there were no significant differences in the adjusted mean change in systolic or diastolic blood pressure by quartile of 25(OH)D. The covariate-adjusted risk of incident hypertension was slightly lower in the upper 3 quartiles of 25(OH)D compared with the lowest quartile, but this was statistically significant only in the third quartile (hazard ratio = 0.67, 95% confidence interval: 0.46, 0.96). There was no significant linear or nonlinear trend in the risk of incident hypertension by untransformed or log-transformed continuous values of 25(OH)D. In postmenopausal women in this study, serum levels of 25(OH)D were not related to changes in blood pressure, and evidence for an association with lower risk of incident hypertension was weak.

Reproductive history and mortality from cardiovascular disease among women textile workers in Shanghai, China

BACKGROUND

Few studies have examined the possible effects of reproductive factors on cardiovascular disease (CVD) risks in Asian women.

METHODS

A cohort of 267,400 female textile workers in Shanghai, China, was administered a questionnaire at enrolment (1989-91) and followed for mortality through 2000. Relative risks (hazard ratios) for ischaemic heart disease (IHD), ischaemic stroke and haemorrhagic stroke were calculated using Cox proportional hazards modelling, adjusting for relevant co-variates.

RESULTS

Risks were not consistently associated with age at menopause, parity, stillbirths, miscarriages or duration of lactation. An increasing trend in IHD mortality risk, but not stroke, was observed with decreasing age at menarche. There was no evidence of increased CVD mortality risk by oral or injectable contraceptive use or induced abortions. As expected, greater mortality rates from CVD and increased CVD risks were also observed with smoking.

CONCLUSIONS

Use of steroid contraceptives, induced abortions and reduced parity from China's one-child-per-family policy has not had an adverse effect on risk of CVD mortality in this cohort.

Risk of lung cancer in relation to contiguous windows of endotoxin exposure among female textile workers in Shanghai

OBJECTIVE

Exposure to endotoxin has been consistently associated with a reduced risk of lung cancer. However, there is a paucity of information regarding temporal aspects of this relationship. The objective of this study was to investigate the associations between contiguous windows of endotoxin exposure and risk of lung cancer.

METHODS

Data were reanalyzed from a case-cohort study (602 cases, 3,038 subcohort) of female textile workers in Shanghai, China. Cumulative endotoxin exposure was partitioned into two windows: ≥20 and <20 years before risk. Exposure-response relations were examined using categorical and non-linear (semi-parametric) models, accounting for confounding by previous exposure windows.

RESULTS

There was an inverse trend of decreasing risk of lung cancer associated with increasing levels of endotoxin exposure ≥20 years before risk (p trend = 0.02). Women in the highest two categories of cumulative exposures had hazard ratios of 0.78 (95% CI 0.60-1.03) and 0.77 (95% CI 0.58-1.02) for lung cancer, respectively, in comparison with unexposed textile workers. There was, however, a weaker association and not statistically significant between lung cancer and endotoxin exposure accumulated in the more recent window (<20 years before risk).

CONCLUSION

Results provide further evidence that endotoxin exposure that occurred 20 years or more before risk confers the strongest protection against lung cancer, indicating a possible early anti-carcinogenic effect. Further studies are needed to better understand the underlying biological mechanisms for this effect.

Abstract 1904: B vitamin intake and incidence of colorectal cancer by tumor site and stage: Results from the Women's Health Initiative cohort

Introduction: The role of one-carbon metabolism related nutrients (folate, riboflavin (B2), B6, and B12) in colorectal carcinogenesis is still not fully understood. Folate and other B vitamins are essential for DNA methylation and repair and higher levels have been associated with a decreased risk for colorectal cancer (CRC) in some studies; however, non-linear relationships have been observed. We investigated the dietary intake of one-carbon nutrients and CRC risk in the WHI Observational Study, a large cohort of postmenopausal women.

Methods: Dietary intake of folate and other B vitamins was determined via a Food Frequency Questionnaire and supplement inventory in 88,045 healthy women (aged 50 – 79 years, recruited between 1994 – 1998). Multivariate Cox proportional hazards regression models was used to estimate associations between nutrient intake and CRC risk and to evaluate differences in the associations by tumor site and stage. Hazard ratios (HR) for the 4th vs. 1st quartile were estimated.

Results: In age-adjusted analyses significantly reduced risks for CRC were observed for the total (supplemental plus dietary) intake of folate (HR=0.82, 95%CI=0.68-0.97), vitamin B12 (HR=0.82, 0.69-0.99), vitamin B6 (HR=0.77, 0.65-0.92), and riboflavin (HR=0.75, 0.63-0.90). After multivariate adjustment (age, BMI, race, prior colonoscopy, smoking, physical activity, postmenopausal HT use) only the total intake of riboflavin (HR=0.80, 0.66-0.96) remained associated with a reduced risk for CRC. For the intake of vitamin B6 a borderline significance was observed (p=0.06, HR=0.85, 0.70-1.02). A site-specific observation was notable for supplemental and total riboflavin intake with a reduced risk for cancer of the distal colon (HRsupp=0.56, 0.33-0.96; HRtotal=0.69, 0.46-1.04) but not in proximal and rectal cancer. In regards to tumor stage, no significant difference was detected for localized and distant disease; the inverse association between the supplemental and total intake of riboflavin and vitamin B6 was limited to regionally spread disease (HRB2;supp=0.66, 0.45-0.96; HRB2;total=0.73, 0.54-0.99; HRB6;supp=0.69, 0.49-0.98; HRB6;total=0.72, 0.53-0.97).

Conclusion: Higher riboflavin and vitamin B6 intake was linked to decreased risk for colorectal cancer in a large cohort of postmenopausal women, with some suggestion for stage- and site-specific associations. Our study provides limited support for an association of other B vitamins with CRC risk. (NIH R01 CA120523, N01WH22110)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1904. doi:10.1158/1538-7445.AM2011-1904

Unexpected excessive chronic obstructive pulmonary disease mortality among female silk textile workers in Shanghai, China

OBJECTIVE

To investigate chronic obstructive pulmonary disease (COPD) mortality among textile workers.

METHODS

A total of 267,400 Chinese female textile employees were monitored for COPD mortality from 1989 to 2000. Textile factories in the cohort were classified into 10 industrial sectors. Age-adjusted mortality, standardized mortality ratios (SMRs) and 95% CIs were calculated by sector. In addition, RRs (HRs) adjusted for smoking and age were calculated for exposure to cotton and silk textile work compared with the other sectors in the cohort.

RESULTS

A majority of textile sectors had lower or similar COPD mortality (age-adjusted SMRs=0.58-1.15) compared with the general female population in the city of Nanjing, China. SMRs for cotton and silk workers were, respectively, 1.02 (95% CI: 0.81 to 1.28) and 2.03 (95% CI: 1.13 to 3.34). Compared with all other textile sectors in the cohort, there was greater COPD mortality among cotton workers (HR=1.40, 95% CI: 1.03 to 1.89) and silk workers (HR=2.54, 95% CI: 1.47 to 4.39).

CONCLUSION

Elevated COPD mortality among cotton workers is consistent with previous reports of adverse respiratory effects of cotton dust. The higher rate of COPD deaths among silk workers was unexpected.

Outcomes after simultaneous pancreas and kidney transplantation and the discriminative ability of the C-peptide measurement pretransplant among type 1 and type 2 diabetes mellitus

BACKGROUND

Earlier studies reporting outcomes after pancreas transplantation have included a combination of C-peptide cutoffs and clinical criteria to classify type 2 diabetes mellitus (T2DM). However, because the kidney is the major site for C-peptide catabolism, C-peptide is unreliable to discriminate the type of diabetes in patients with kidney disease.

METHODS

To improve the discriminative power and better classify the type of diabetes, we used a composite definition to identify T2DM: presence of C-peptide, negative glutamic acid decarboxylase antibody, absence of diabetic ketoacidosis, and use of oral hypoglycemics. Additionally among T2DM patients with end-stage renal disease (ESRD), body mass index of <30 kg/m(2) and use of <1 u/kg of insulin per day were selection criteria for suitablity for simultaneous pancreas and kidney transplantation (SPKT). We compared graft and patient survival between T1DM and T2DM after SPKT.

RESULTS

Our study cohort consisted of 80 patients, 10 of whom were assigned as T2DM based on our study criteria. Approximately 15% of patients with T1DM had detectable C-peptide. Cox regression survival analyses found no significant differences in allograft (pancreas and kidney) or patient survival between the 2 groups. The mean creatinine clearance at 1 year estimated by the modification of Diet in Renal Disease (MDRD) equation was not significantly different between the 2 groups. Among those with 1 year of follow-up, all patients with T2DM had glycosylate hemoglobin of <6.0 at 1 year versus 92% of those with T1DM.

CONCLUSION

SPKT should be considered in the therapeutic armamentarium for renal replacement in selected patients with T2DM and ESRD. Use of C-peptide measurements for ESRD patients can be misleading as the sole criterion to determine the type of diabetes.

Lung cancer and occupational exposures other than cotton dust and endotoxin among women textile workers in Shanghai, China

OBJECTIVES

Numerous epidemiological studies of lung cancer among textile workers worldwide consistently indicate reduced risks related to cotton dust exposure, presumably due to endotoxin contamination. Our objective was to investigate associations with other exposures potentially related to lung cancer, including wool and synthetic fibre dusts, formaldehyde, silica, dyes and metals, that have only been studied to a limited extent in the textile industry.

METHODS

We conducted a case-cohort study nested within a cohort of 267,400 women textile workers in Shanghai, China. We compared work assignments and exposure histories of 628 incident lung cancer cases, diagnosed during 1989-1998, with those of a reference subcohort of 3188 workers. We reconstructed exposures with a job-exposure matrix developed specifically for textile factories. Cox proportional hazards modelling was applied to estimate age/smoking-adjusted relative risks (hazard ratios) and risk gradients associated with job assignments and specific agents other than cotton dust and endotoxin.

RESULTS

No associations were observed for lung cancer with wool, silk or synthetic fibre dusts, or with most other agents. However, increased risks, although statistically imprecise, were noted for ≥ 10 years' exposures to silica (adjusted HR 3.5, 95% CI 1.0 to 13) and ≥ 10 years' exposures to formaldehyde (adjusted HR 2.1, 95% CI 0.4 to 11).

CONCLUSIONS

Exposures to silica and formaldehyde, although not widespread among the cohort, may have increased lung cancer risk. Silica is an established human lung carcinogen, whereas there is only weak prior evidence supporting an association with formaldehyde. Both exposures warrant consideration as potential lung carcinogens in textile manufacturing.

Selected estrogen receptor 1 and androgen receptor gene polymorphisms in relation to risk of breast cancer and fibrocystic breast conditions among Chinese women

BACKGROUND

Polymorphisms in sex hormone receptor-encoding genes may alter the activity of sex hormone receptors and thereby affect susceptibility to breast cancer and related outcomes.

METHODS

In a case-control study of women from Shanghai, China, we examined the risk of breast cancer and fibrocystic breast conditions associated with the ESR1 PvuII (rs2234693) and XbaI (rs9340799) and AR CAG repeat ((CAG)(n)) and GGC repeat ((GGC)(n)) polymorphisms among 614 women with breast cancer, 467 women with fibrocystic conditions, and 879 women without breast disease. We also evaluated whether risk differed by the presence/absence of proliferative changes (in the extratumoral epithelium or fibrocystic lesion), menopausal status, or body mass index (BMI). Age-adjusted odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated using logistic regression.

RESULTS

Only associations with AR (CAG)(n) and (GGC)(n) genotypes were detected. Allocating AR (CAG)(n) genotypes into six categories, with the (CAG)(22-24)/(CAG)(22-24) genotype category designated as the reference group, the (CAG)(>24)/(CAG)(>24) genotype category was associated with an increased risk of fibrocystic breast conditions (OR, 1.8; 95% CI, 1.1-3.0). Relative to the AR (GGC)(17)/(GGC)(17) genotype, the (GGC)(17)/(GGC)(14) genotype was associated with elevated risks of incident breast cancer (OR, 2.6; 95% CI, 1.3-5.4) and fibrocystic conditions (OR, 2.3; 95% CI, 1.1-4.5). Results did not differ according to proliferation status, menopausal status, or BMI.

CONCLUSION

Although these data lend support for a link between AR variation and breast disease development, given the low frequency of the putative risk-conferring genotypes and other constraints, further confirmation of our results is needed.

Biomarkers of dietary exposure are associated with lower risk of breast fibroadenomas in Chinese women

Fibroadenomas are the most common benign breast condition among women and account for up to 50% of all breast biopsies being performed. Although considered a benign condition, fibroadenomas utilize substantial resources for management and treatment to rule out potential malignancies. Dietary factors may influence benign fibrocystic breast conditions, but little is known of their association with fibroadenomas. We examined possible associations between a broad spectrum of circulating biomarkers of dietary intake and risk of fibroadenomas. Participants were women in a breast self-examination trial in Shanghai, China who were diagnosed with fibroadenomas (n = 258) and 1035 controls. Conditional logistic regression was used to estimate adjusted odds ratios (OR) and 95% CI. Isoflavone concentrations were inversely associated with risk of fibroadenomas. Adjusted OR (95% CI) for the highest versus the lowest quartile of plasma concentration were 0.36 (0.16-0.79; P-trend < 0.001) for daidzein and 0.39 (0.19-0.84; P-trend = 0.010) for genistein. We also observed inverse associations between higher percentages of the RBC (n-3) fatty acids, eicosapentaenoic acid (EPA) ([0.38 (0.19-0.77); P-trend = 0.007] and docosapentaenoic acid (DPA) [0.32 (0.15-0.70); P-trend = 0.024], and fibroadenoma risk. Circulating concentrations of carotenoids, vitamin C, retinol, and ferritin were not associated with fibroadenoma risk. The inverse associations between plasma isoflavone concentrations and RBC EPA and DPA and fibroadenoma risk suggest that higher intakes of soy foods and fatty fish may lower the risk of fibroadenomas.

Fruit and vegetable intakes are associated with lower risk of breast fibroadenomas in Chinese women

Fibroadenomas are common benign breast conditions among women and account for approximately 50% of breast biopsies performed. Dietary factors are known to influence benign breast conditions in the aggregate, but little is known of their association specifically with fibroadenoma. Our objective in this study was to evaluate the association between dietary and other factors and fibroadenoma risk. A case-control study, nested in a randomized trial of breast self-examination (BSE) in Chinese textile workers in Shanghai, China, was conducted between 1989 and 2000. The study sample included 327 affected women and 1070 controls. Women were administered a FFQ and a questionnaire that elicited reproductive and gynecological history and other information. Odds ratios, as estimates of relative risks, were calculated using multivariate conditional logistic regression. Significant decreasing trends in risk of fibroadenoma were observed with intake of fruits and vegetables and with number of live births, and a reduced risk was also associated with natural menopause, oral contraceptive use, and moderate exercise (walking and gardening). Increased risk of fibroadenoma was associated with heavy physical activity in one's 20s, breast cancer in a first-degree relative, and a history of prior benign breast lumps; and significant increasing trends in risk were observed with numbers of BSE per year and years of education. In conclusion, a diet rich in fruits and vegetables and the use of oral contraceptives may reduce risk of fibroadenoma.

Effect of melanin on enzymatic hydrolysis of cellulosic waste

Wood waste powder from Tectona grandis containing melanin was less susceptible to enzymatic hydrolysis than powder without melanin. About a 53% increase in saccharification was noted when melanin was removed. Melanin caused inhibition to all cellulolytic enzymes, but in different degrees. Endo-beta-1,4-glucanase and beta-glucosidase were markedly inhibited when melanin was preincubated with enzyme, while exo-beta-1,4-glucanase was severely inhibited when melanin was preincubated with substrate. The latter was found to be dependent on the contact time. The activities of endo-beta-1,4-glucanase and beta-glucosidase were noncompetitively inhibited by melanin.

Dietary and stored iron as predictors of breast cancer risk: A nested case-control study in Shanghai

Increases in risk of breast cancer in successive generations of migrants to the United States from China and rapid temporal changes in incidence rates in China following social and economic changes clearly implicate environmental factors in the etiology of this disease. Case-control and cohort studies have provided evidence that at least some of these factors may be dietary. Iron, an essential element necessary for cell function, has also been demonstrated to have potential carcinogenic and co-carcinogenic activities. Iron overload, which was previously uncommon, has become more common in the United States than iron deficiency and may be increasing in China concurrently with dramatic increases in meat consumption. A case-control study nested in a cohort of women in Shanghai, China, was conducted to evaluate possible associations between risk of proliferative and nonproliferative fibrocystic changes as well as breast cancer and dietary iron intake and plasma ferritin levels. Plasma ferritin levels and reported dietary iron intake were compared in 346 women with fibrocystic changes, 248 breast cancer cases and 1,040 controls. Increasing ferritin levels were significantly associated with increasing risk of nonproliferative fibrocystic changes (OR: 2.51, 95% CI: 1.16-5.45, p trend = 0.04). Similar, but weaker, trends were observed for proliferative changes and for breast cancer. Risk of breast cancer relative to the risk of fibrocystic changes was associated with dietary iron intake in women with nonproliferative fibrocystic changes (OR: 2.63, 95% CI: 1.04-6.68, p = 0.02). In conclusion, this study finds significant associations between iron (stored and dietary) and fibrocystic disease and breast cancer.

Genetic variation in CYP19A1 and risk of breast cancer and fibrocystic breast conditions among women in Shanghai, China

CYP19A1 encodes for aromatase, which irreversibly converts androgens to estrogens; variation in this gene may affect individual susceptibility to breast cancer and other sex hormone-dependent outcomes. In a case-control study nested within a breast self-examination trial conducted in China, we examined whether CYP19A1 polymorphisms (rs1870049, rs1004982, rs28566535, rs936306, rs11636639, rs767199, rs4775936, rs11575899, rs10046, and rs4646) were associated with risk of breast cancer and fibrocystic breast conditions. Cases were diagnosed with breast cancer (n = 614) or fibrocystic breast conditions (n = 465) during 1989 to 2000. Controls were free of breast disease during the same period (n = 879). Presence of proliferative changes within the extratumoral tissue of women with breast cancer and the lesions of women with fibrocystic conditions only was assessed. None of the polymorphisms were associated with overall risk of breast cancer or fibrocystic breast conditions. Differences in breast cancer risk, however, were observed by proliferation status. The risk of breast cancer with (but not without) proliferative fibrocystic conditions was increased among women homozygous for the minor allele of rs1004982 (C), rs28566535 (C), rs936306 (T), and rs4775936 (C) relative to those homozygous for the major allele [age-adjusted odds ratios (95% confidence intervals), 2.19 (1.24-3.85), 2.20 (1.27-3.82), 1.94 (1.13-3.30), and 1.95 (1.07-3.58), respectively]. Also, haplotypes inferred using all polymorphisms were not associated with overall risk of either outcome, although some block-specific haplotypes were associated with an increased risk of breast cancer with concurrent proliferative fibrocystic conditions. Our findings suggest that CYP19A1 variation may enhance breast cancer development in some women, but further confirmation is warranted.