Background

Many factors contribute to mortality in older women, but their relative importance and independent contribution have been poorly characterized.

Methods

From 1990 to 1992, we assessed demographics, lifestyle measures, prevalent disease, medication use, anthropometrics, vital signs, and physical function in 17 748 postmenopausal women. We used proportional hazards modeling to evaluate their association with mortality.

Results

During 9 years of follow-up, 1886 women (10.6%) died. The relative hazard (RH) of death was approximately 1.5 (95% confidence interval [CI], 1.5-1.6) per 5 years of age, 1.4 (95% CI, 1.2-1.6) for a history of heart disease, and 1.9 (95% CI, 1.6-2.3) for a history of breast cancer. Modifiable risk factors associated with mortality included smoking (RH, 3.7 [95% CI, 3.1-4.5] for current smokers with a > or =50 pack-year history) and systolic blood pressure (RH, 1.3 [95% CI, 1.1-1.5], fifth vs first quintile). Elevated waist-hip ratio was associated with higher mortality (RH, 1.3 [95% CI, 1.1-1.5], fifth vs first quintile), but obesity was associated with lower mortality (RH, 0.7 [95% CI, 0.6-0.9] for body mass index [calculated as weight in kilograms divided by the square of height in meters] of >35.0 vs 18.5-25.0). Poor results on the timed Up and Go Test, a measure of physical function, were also strongly associated with mortality (RH, 1.7 [95% CI, 1.4-2.0], fifth vs first quintile).

Conclusions

Simple measures are sufficient to stratify postmenopausal women into groups at high and low risk of dying. Smoking, central obesity, blood pressure, and physical function are potentially modifiable risk factors, although clinical trials are required to demonstrate that change in these factors affects mortality.

Background

Women with elevated mammographic density have an increased risk of developing breast cancer. However, among women diagnosed with breast cancer, it is unclear whether higher density portends reduced survival, independent of other factors.

Methods

We evaluated relationships between mammographic density and risk of death from breast cancer and all causes within the US Breast Cancer Surveillance Consortium. We studied 9232 women diagnosed with primary invasive breast carcinoma during 1996-2005, with a mean follow-up of 6.6 years. Mammographic density was assessed using the Breast Imaging Reporting and Data System (BI-RADS) density classification. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression; women with scattered fibroglandular densities (BI-RADS 2) were the referent group. All statistical tests were two-sided.

Results

A total of 1795 women died, of whom 889 died of breast cancer. In multivariable analyses (adjusted for site, age at and year of diagnosis, American Joint Committee on Cancer stage, body mass index, mode of detection, treatment, and income), high density (BI-RADS 4) was not related to risk of death from breast cancer (HR = 0.92, 95% CI = 0.71 to 1.19) or death from all causes (HR = 0.83, 95% CI = 0.68 to 1.02). Analyses stratified by stage and other prognostic factors yielded similar results, except for an increased risk of breast cancer death among women with low density (BI-RADS 1) who were either obese (HR = 2.02, 95% CI = 1.37 to 2.97) or had tumors of at least 2.0 cm (HR = 1.55, 95% CI = 1.14 to 2.09).

Conclusions

High mammographic breast density was not associated with risk of death from breast cancer or death from any cause after accounting for other patient and tumor characteristics. Thus, risk factors for the development of breast cancer may not necessarily be the same as factors influencing the risk of death after breast cancer has developed.

Although elevated circulating estrogens are associated with increased postmenopausal breast cancer risk, less is known regarding the role of estrogen metabolism in breast carcinogenesis. We conducted a case-cohort study within the Breast and Bone Follow-up to the Fracture Intervention Trial to assess serum estrogens and estrogen metabolites (EMs) in 407 incident breast cancer cases diagnosed during follow-up and a subcohort of 496 women. In 1992-93, women completed a baseline questionnaire and provided blood samples. Hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for geography and trial participation status, were estimated using Cox proportional hazard regression. Serum concentrations of EMs were measured by liquid chromatography-tandem mass spectrometry. EMs (quintiles, Q) were analyzed individually, as metabolic pathways (C-2, -4 or -16) and as ratios. Elevated circulating estradiol was associated with increased breast cancer risk (HRQ5vsQ1 = 1.86; 95% CI: 1.19-2.90; P trend = 0.04). An elevated ratio of the 2-hydroxylation pathway (HRQ5vsQ1 = 0.69; 95% CI: 0.46-1.05; P trend = 0.01) and 4-hydroxylation pathway (HRQ5vsQ1 = 0.61; 95% CI: 0.40-0.93; P trend = 0.004) to parent estrogens (estradiol and estrone) was inversely associated with risk. A higher ratio of the 2/16-hydroxylation pathways was associated with reduced risk (HRQ5vsQ1 = 0.60; 95% CI: 0.40-0.90; P trend = 0.002). Increased 2- or 4-hydroxylation of parent estrogens may lower risk of postmenopausal breast cancer. Analyses of metabolic pathways may help elucidate the role of estrogen metabolism in breast carcinogenesis.

Our knowledge of epidemiologic risk factors for ovarian cancer supports a role for androgens in the pathogenesis of this disease; however, few studies have examined associations between circulating androgens and ovarian cancer risk. Using highly sensitive LC-MS/MS assays, we evaluated associations between pre-diagnostic serum levels of 12 androgens, including novel androgen metabolites that reflect androgen activity in tissues, and ovarian cancer risk among postmenopausal women in a nested case-control study in the Women's Health Initiative (WHI) Observational Study (OS). We frequency-matched 169 ovarian cancer cases to 410 controls from women enrolled in WHI-OS who were not using menopausal hormones at enrollment/blood draw. We estimated associations overall and by subtype (n = 102 serous/67 non-serous) using multivariable adjusted logistic regression. Androgen/androgen metabolite levels were not associated with overall ovarian cancer risk. In analyses by subtype, women with increased levels of androsterone-glucuronide (ADT-G) and total 5-α reduced glucuronide metabolites (markers of tissue-level androgenic activity) were at increased risk of developing non-serous ovarian cancer: ADT-G tertile (T)3 versus T1 odds ratio [OR] (95% confidence interval [CI]) 4.36 (1.68-11.32), p-heterogeneity 0.002; total glucuronide metabolites 3.63 (1.47-8.95), 0.002. Risk of developing serous tumors was unrelated to these markers. ADT-G and total glucuronide metabolites, better markers of tissue-level androgenic activity in women than testosterone, were associated with an increased risk of developing non-serous ovarian cancer. Our work demonstrates that sex steroid metabolism is important in the etiology of non-serous ovarian cancers and supports a heterogeneous hormonal etiology across histologic subtypes of ovarian cancer.

Purpose

Menopausal hormone therapy (MHT) use induces alterations in circulating estrogens/estrogen metabolites, which may contribute to the altered risk of reproductive tract cancers among current users. Thus, the current study assessed associations between circulating estrogens/estrogen metabolites and ovarian and endometrial cancer risk among MHT users.

Methods

We conducted a nested case-control study among postmenopausal women using MHT at baseline in the Women's Health Initiative Observational Study (179 ovarian cancers, 396 controls; 230 endometrial cancers, 253 controls). Multivariable logistic regression was utilized to estimate odds ratios and 95% confidence intervals overall and by subtype.

Results

Estrogen/estrogen metabolite levels were not associated with overall or serous ovarian cancer risk, examined separately. However, unconjugated estradiol was positively associated with non-serous ovarian cancer risk [quintile 5 vs. quintile 1: 3.01 (1.17-7.73); p-trend = 0.03; p-het < 0.01]. Endometrial cancer risk was unrelated to estrogen/estrogen metabolite levels among women who took combined estrogen/progestin therapy (EPT).

Conclusions

These findings provide novel evidence that may support a heterogeneous hormonal etiology across ovarian cancer subtypes. Circulating estrogens did not influence endometrial cancer risk among women with EPT-induced high-estrogen levels. Larger studies are needed to delineate the relationship between ovarian/endometrial cancer subtypes and estrogen levels in the context of MHT use.

Although elevated circulating estrogens are associated with increased postmenopausal breast cancer risk, less is known regarding the role of estrogen metabolism in breast carcinogenesis. We conducted a case-cohort study within the Breast and Bone Follow-up to the Fracture Intervention Trial to assess serum estrogens and estrogen metabolites (EMs) in 407 incident breast cancer cases diagnosed during follow-up and a subcohort of 496 women. In 1992-93, women completed a baseline questionnaire and provided blood samples. Hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for geography and trial participation status, were estimated using Cox proportional hazard regression. Serum concentrations of EMs were measured by liquid chromatography-tandem mass spectrometry. EMs (quintiles, Q) were analyzed individually, as metabolic pathways (C-2, -4 or -16) and as ratios. Elevated circulating estradiol was associated with increased breast cancer risk (HRQ5vsQ1 = 1.86; 95% CI: 1.19-2.90; P trend = 0.04). An elevated ratio of the 2-hydroxylation pathway (HRQ5vsQ1 = 0.69; 95% CI: 0.46-1.05; P trend = 0.01) and 4-hydroxylation pathway (HRQ5vsQ1 = 0.61; 95% CI: 0.40-0.93; P trend = 0.004) to parent estrogens (estradiol and estrone) was inversely associated with risk. A higher ratio of the 2/16-hydroxylation pathways was associated with reduced risk (HRQ5vsQ1 = 0.60; 95% CI: 0.40-0.90; P trend = 0.002). Increased 2- or 4-hydroxylation of parent estrogens may lower risk of postmenopausal breast cancer. Analyses of metabolic pathways may help elucidate the role of estrogen metabolism in breast carcinogenesis.

Background

A potential protective role for estrogen in colon carcinogenesis has been suggested based on exogenous hormone use, but it is unclear from previous studies whether endogenous estrogens are related to colorectal cancer risk. These few prior studies focused on parent estrogens; none evaluated effects of estrogen metabolism in postmenopausal women.

Methods

We followed 15,595 women (ages 55-80 years) enrolled in the Breast and Bone Follow-up to the Fracture Intervention Trial (B∼FIT) who donated blood between 1992 and 1993 for cancer through December 2004. A panel of 15 estrogen metabolites (EM), including estradiol and estrone, were measured in serum from 187 colorectal cancer cases and a subcohort of 501 women not using exogenous hormones at blood draw. We examined EM individually, grouped by pathway (hydroxylation at the C-2, C-4, or C-16 position) and by ratios of the groupings using Cox proportional hazards regression models.

Results

No significant associations were seen for estrone (HRQ4 vs. Q1 = 1.15; 95% CI, 0.69-1.93; Ptrend = 0.54), estradiol (HRQ4 vs. Q1 = 0.98; 95% CI, 0.58-1.64; Ptrend > 0.99), or total EM (the sum of all EM; HRQ4 vs. Q1 = 1.35; 95% CI, 0.81-2.24; Ptrend = 0.33). Most metabolites in the 2-, 4-, or 16-pathway were unrelated to risk, although a borderline trend in risk was associated with high levels of 17-epiestriol.

Conclusion

Circulating estrogens and their metabolites were generally unrelated to colorectal cancer risk in postmenopausal women.

Impact

Additional studies are needed to understand how exogenous estrogen may prevent colorectal cancer.

Background

Postmenopausal pregnenolone and/or progesterone levels in relation to endometrial and ovarian cancer risks have been infrequently evaluated. To address this, we utilized a sensitive and reliable assay to quantify prediagnostic levels of seven markers related to endogenous hormone metabolism.

Methods

Hormones were quantified in baseline serum collected from postmenopausal women in a cohort study nested within the Breast and Bone Follow-up to the Fracture Intervention Trial (B∼FIT). Women using exogenous hormones at baseline (1992-1993) were excluded. Incident endometrial (n = 65) and ovarian (n = 67) cancers were diagnosed during 12 follow-up years and compared with a subcohort of 345 women (no hysterectomy) and 413 women (no oophorectomy), respectively. Cox models with robust variance were used to estimate cancer risk.

Results

Circulating progesterone levels were not associated with endometrial [tertile (T)3 vs. T1 HR (95% confidence interval): 1.87 (0.85-4.11); P _trend = 0.17] or ovarian cancer risk [1.16 (0.58-2.33); 0.73]. Increasing levels of the progesterone-to-estradiol ratio were inversely associated with endometrial cancer risk [T3 vs. T1: 0.29 (0.09-0.95); 0.03]. Increasing levels of 17-hydroxypregnenolone were inversely associated with endometrial cancer risk [0.40 (0.18-0.91); 0.03] and positively associated with ovarian cancer risk [3.11 (1.39-6.93); 0.01].

Conclusions

Using sensitive and reliable assays, this study provides novel data that endogenous progesterone levels are not strongly associated with incident endometrial or ovarian cancer risks. 17-hydroxypregnenolone was positively associated with ovarian cancer and inversely associated with endometrial cancer.

Impact

While our results require replication in large studies, they provide further support of the hormonal etiology of endometrial and ovarian cancers.

The association of progesterone/progesterone metabolites with elevated mammographic breast density (MBD) and delayed age-related terminal duct lobular unit (TDLU) involution, strong breast cancer risk factors, has received limited attention. Using a reliable liquid chromatography-tandem mass-spectrometry assay, we quantified serum progesterone/progesterone metabolites and explored cross-sectional relationships with MBD and TDLU involution among women, ages 40-65, undergoing diagnostic breast biopsy. Quantitative MBD measures were estimated in pre-biopsy digital mammograms. TDLU involution was quantified in diagnostic biopsies. Adjusted partial correlations and trends across MBD/TDLU categories were calculated. Pregnenolone was positively associated with percent MBD-area (MBD-A, rho: 0.30; p-trend = 0.01) among premenopausal luteal phase women. Progesterone tended to be positively associated with percent MBD-A among luteal phase (rho: 0.26; p-trend = 0.07) and postmenopausal (rho: 0.17; p-trend = 0.04) women. Consistent with experimental data, implicating an elevated 5α-pregnanes/3α-dihydroprogesterone (5αP/3αHP) metabolite ratio in breast cancer, higher 5αP/3αHP was associated with elevated percent MBD-A among luteal phase (rho: 0.29; p-trend = 0.08), but not postmenopausal women. This exploratory analysis provided some evidence that endogenous progesterone and progesterone metabolites might be correlated with MBD, a strong breast cancer risk factor, in both pre- and postmenopausal women undergoing breast biopsy. Additional studies are needed to understand the role of progesterone/progesterone metabolites in breast tissue composition and breast cancer risk.

Estrogen metabolites may have different genotoxic and mitogenic properties yet their relationship with endometrial and ovarian cancer risk remains unclear. Within the Breast and Bone Follow-up to the Fracture Intervention Trial (B ∼ FIT, n = 15,595), we conducted a case-cohort study to evaluate 15 pre-diagnostic serum estrogens and estrogen metabolites with risk of incident endometrial and ovarian cancer among postmenopausal women not on hormone therapy. Participants included 66 endometrial and 67 ovarian cancer cases diagnosed during follow-up (∼ 10 years) and subcohorts of 346 and 416 women, respectively, after relevant exclusions. Serum concentrations were measured by liquid chromatography-tandem mass spectrometry. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard regression. Exposures were categorized in tertiles (T) and analyzed individually, as metabolic pathways (C-2, -4, or -16) and as ratios to parent estrogens (estradiol, estrone). Estradiol was significantly associated with increased endometrial cancer risk (BMI-adjusted HRT3vsT1 = 4.09, 95% CI 1.70, 9.85; p trend = 0.003). 2-Hydroxyestrone and 16α-hydroxyestrone were not associated with endometrial risk after estradiol adjustment (2-OHE1:HRT3vsT1 = 1.97, 95% CI 0.78, 4.94; 16-OHE1:HRT3vsT1 = 1.50, 95% CI 0.65, 3.46; p trend = 0.16 and 0.36, respectively). Ratios of 2- and 4-pathway catechol-to-methylated estrogens remained positively associated with endometrial cancer after BMI or estradiol adjustment (2-pathway catechols-to-methylated: HRT3vsT1 = 4.02, 95% CI 1.60, 10.1; 4-pathway catechols-to-methylated: HRT3vsT1 = 4.59, 95% CI 1.64, 12.9; p trend = 0.002 for both). Estrogens and estrogen metabolites were not associated with ovarian cancer risk; however, larger studies are needed to better evaluate these relationships. Estrogen metabolism may be important in endometrial carcinogenesis, particularly with less extensive methylation of 2- or 4-pathway catechols associated with elevated endometrial cancer risk.