Association of serum sex steroid hormone hemodilution and body mass index among healthy postmenopausal women

PURPOSE

Hemodilution refers to reduced concentrations of analytes in the blood secondary to increased fluid volume. Given that obesity is associated with expanded vascular volume, hemodilution may result in a lower ratio of blood concentrations of analytes among heavier subjects. Assessing the relationship of hormone concentration to total mass varies by body mass index (BMI) is etiologically important because obesity is related to hormone metabolism and cancer risk.

METHODS

We evaluated data for 194 postmenopausal controls in an endometrial cancer case-control study. Height, weight, and serum hormone concentrations were measured previously. We estimated serum hormone mass from concentration based on estimates of calculated plasma volume. We assessed the effect of BMI on relationships of sex steroid hormone concentration and mass using multivariate linear regression.

RESULTS

Higher BMI was associated with increased estrone, estrone sulfate, estradiol, and albumin-bound estradiol concentrations and masses (p-trend ≤ 0.001). With increasing BMI, androstenedione concentration did not change significantly (p-trend = 0.548), but its mass increased (p-trend = 0.024).

CONCLUSIONS

Relationships of sex steroid hormone concentration and mass were generally similar, except for androstenedione in which the relationship was only significant for mass. Future studies to assess both sex steroid hormone concentration and mass may have value in etiological research.

Associations of breast cancer risk factors with tumor subtypes: a pooled analysis from the Breast Cancer Association Consortium studies

BACKGROUND

Previous studies have suggested that breast cancer risk factors are associated with estrogen receptor (ER) and progesterone receptor (PR) expression status of the tumors.

METHODS

We pooled tumor marker and epidemiological risk factor data from 35,568 invasive breast cancer case patients from 34 studies participating in the Breast Cancer Association Consortium. Logistic regression models were used in case-case analyses to estimate associations between epidemiological risk factors and tumor subtypes, and case-control analyses to estimate associations between epidemiological risk factors and the risk of developing specific tumor subtypes in 12 population-based studies. All statistical tests were two-sided.

RESULTS

In case-case analyses, of the epidemiological risk factors examined, early age at menarche (≤12 years) was less frequent in case patients with PR(-) than PR(+) tumors (P = .001). Nulliparity (P = 3 × 10(-6)) and increasing age at first birth (P = 2 × 10(-9)) were less frequent in ER(-) than in ER(+) tumors. Obesity (body mass index [BMI] ≥ 30 kg/m(2)) in younger women (≤50 years) was more frequent in ER(-)/PR(-) than in ER(+)/PR(+) tumors (P = 1 × 10(-7)), whereas obesity in older women (>50 years) was less frequent in PR(-) than in PR(+) tumors (P = 6 × 10(-4)). The triple-negative (ER(-)/PR(-)/HER2(-)) or core basal phenotype (CBP; triple-negative and cytokeratins [CK]5/6(+) and/or epidermal growth factor receptor [EGFR](+)) accounted for much of the heterogeneity in parity-related variables and BMI in younger women. Case-control analyses showed that nulliparity, increasing age at first birth, and obesity in younger women showed the expected associations with the risk of ER(+) or PR(+) tumors but not triple-negative (nulliparity vs parity, odds ratio [OR] = 0.94, 95% confidence interval [CI] = 0.75 to 1.19, P = .61; 5-year increase in age at first full-term birth, OR = 0.95, 95% CI = 0.86 to 1.05, P = .34; obesity in younger women, OR = 1.36, 95% CI = 0.95 to 1.94, P = .09) or CBP tumors.

CONCLUSIONS

This study shows that reproductive factors and BMI are most clearly associated with hormone receptor-positive tumors and suggest that triple-negative or CBP tumors may have distinct etiology.

Endometrial cancer and genetic variation in PTEN, PIK3CA, AKT1, MLH1, and MSH2 within a population-based case-control study

OBJECTIVE

We assessed whether common genetic variation in PTEN, PIK3CA, AKT1, MLH1, and MSH2-genes that reportedly are frequently altered in endometrial cancer-was associated with risk of endometrial cancer.

METHODS

Using data from a population-based case-control study in Poland (PECS) of 417 cases and 407 matched controls, we genotyped 76 tagging single nucleotide polymorphisms (tagSNPs; located in or within 10 kb upstream or 5 kb downstream of the gene of interest, minor allele frequency >=5% among various ethnic groups, and not already represented by another tagSNP at a LD of r(2) >=0.80) on an Illumina Custom Infinium iSelect assay that included over 29,000 SNPs in 1316 genes. For individual SNPs, we used unconditional logistic regression models, adjusted for age and site, to generate odds ratios (ORs) and 95% confidence intervals (CIs). To replicate the one statistically significant association in PECS, we independently genotyped that tagSNP among 1141 endometrial cancer cases and 2275 controls from the SEARCH study in the UK. We assessed haplotypes via extended haplotype blocks and the sequential haplotype scan method.

RESULTS

The rs2677764 tagSNP in PIK3CA was statistically significantly associated with endometrial cancer in PECS (OR=1.42, 95% CI, 1.03-1.95; P=0.03) but not SEARCH (OR=0.98, 95% CI=0.82-1.17). Of the 25 haplotypes observed in at least 5% of cases and controls in PECS, only 1, in PIK3CA, was statistically significantly associated with endometrial cancer (OR=1.39, 95% CI, 1.00-1.93). All haplotype global p-values were null.

CONCLUSION

Common genetic variation in PTEN, PIK3CA, AKT1, MLH1, or MSH2 was not statistically significantly associated with endometrial cancer.

Effects of HIV-1 and herpes simplex virus type 2 infection on lymphocyte and dendritic cell density in adult foreskins from Rakai, Uganda

BACKGROUND

Male circumcision reduces human immunodeficiency virus (HIV) and herpes simplex virus type 2 (HSV-2) acquisition, and HSV-2 infection is associated with an increased risk of HIV acquisition. To assess the cellular basis for these associations, we estimated immunologic cellular densities in foreskin tissue.

METHODS

Immunostained CD1a(+) dendritic cell and CD4(+) and CD8(+) T cell densities were quantified in foreskin samples obtained from medical circumcision in Rakai, Uganda (35 HIV-infected, HSV-2-infected men; 5 HIV-infected, HSV-2-uninfected men; 22 HIV-uninfected, HSV-2-infected men; and 29 HIV-uninfected, HSV-2-uninfected men.

RESULTS

CD1A(+) dendritic cell densities did not vary by HIV or HSV-2 status. Compared with densities in HIV-uninfected, HSV-2-uninfected men (mean, 26.8 cells/mm(2)), CD4(+) T cell densities were similar in the HIV-infected, HSV-2-infected group (mean, 28.7 cells/mm(2)), were significantly decreased in the HIV-infected, HSV-2-uninfected group (mean, 11.2; P < .05), and were increased in the HIV-uninfected, HSV-2-infected group (mean, 68.7; P < .05). Dermal CD8(+) T cell densities were higher in the HIV and HSV-2-coinfected group (mean, 102.9) than in the HIV-uninfected, HSV-2-uninfected group (mean, 10.0; P < .001), the HIV-infected, HSV-2-uninfected group (mean, 27.3; P < .001), and the HIV-uninfected, HSV-2-infected group (mean, 25.3; P < .005).

DISCUSSION

The increased CD4(+) cellular density in the HIV-uninfected, HSV-2-infected men may help to explain why HSV-2-infected men are at increased risk of HIV acquisition. The absence of this increase in men coinfected with both HIV and HSV-2 is likely in part the result of the progressive loss of CD4(+) cells in HIV infection. Conversely, HIV and HSV-2 coinfection appears to synergistically increase CD8(+) T cell densities.

Assessing interactions between the associations of common genetic susceptibility variants, reproductive history and body mass index with breast cancer risk in the breast cancer association consortium: a combined case-control study

Introduction

Several common breast cancer genetic susceptibility variants have recently been identified. We aimed to determine how these variants combine with a subset of other known risk factors to influence breast cancer risk in white women of European ancestry using case-control studies participating in the Breast Cancer Association Consortium.

Methods

We evaluated two-way interactions between each of age at menarche, ever having had a live birth, number of live births, age at first birth and body mass index (BMI) and each of 12 single nucleotide polymorphisms (SNPs) (10q26-rs2981582 (FGFR2), 8q24-rs13281615, 11p15-rs3817198 (LSP1), 5q11-rs889312 (MAP3K1), 16q12-rs3803662 (TOX3), 2q35-rs13387042, 5p12-rs10941679 (MRPS30), 17q23-rs6504950 (COX11), 3p24-rs4973768 (SLC4A7), CASP8-rs17468277, TGFB1-rs1982073 and ESR1-rs3020314). Interactions were tested for by fitting logistic regression models including per-allele and linear trend main effects for SNPs and risk factors, respectively, and single-parameter interaction terms for linear departure from independent multiplicative effects.

Results

These analyses were applied to data for up to 26,349 invasive breast cancer cases and up to 32,208 controls from 21 case-control studies. No statistical evidence of interaction was observed beyond that expected by chance. Analyses were repeated using data from 11 population-based studies, and results were very similar.

Conclusions

The relative risks for breast cancer associated with the common susceptibility variants identified to date do not appear to vary across women with different reproductive histories or body mass index (BMI). The assumption of multiplicative combined effects for these established genetic and other risk factors in risk prediction models appears justified.

Abstract P3-12-05: Genetic Variation in Prolactin and Prolactin Receptor, and Relationships with Serum Prolactin Levels and Breast Cancer Risk

Background: Studies support the hypothesis that high circulating levels of the hormone prolactin increase breast cancer risk. It remains unclear if genetic factors are associated with interindividual variation in circulating prolactin and subsequent breast cancer risk. We examined the relationship between single nucleotide polymorphisms (SNPs) in prolactin (PRL) and prolactin receptor (PRLR), serum prolactin levels and breast cancer risk in a population based case-control study.

Methods: We genotyped 8 PRL and 20 PRLR tag SNPs in 1943 cases and 2229 controls (82% and 89% of enrolled, respectively). Cases were women 20-74 years old, diagnosed with in situ or invasive breast cancer between 2000 and 2003, and living in Warsaw or Lodz, Poland. Controls were cancer-free women selected from a population registry, matched to cases on age and city. Blood samples were provided at the study interview. Serum prolactin levels were measured in a subset of 773 controls using the Bayer Advia Centaur immunoassay. Odds ratios and 95% CIs for genotype-breast cancer associations were estimated using unconditional logistic regression, adjusting for age and city. Geometric mean prolactin levels and 95% confidence intervals (CI) were estimated using linear regression, adjusting for age, city, blood collection time, and day of menstrual cycle (premenopausal). Log-additive model Wald P-values were used to test for linear trends. Analyses were stratified by menopausal status, and all statistical tests were 2-sided (alpha=0.05). To account for multiple comparisons, P-values were adjusted using the Benjamini and Hochberg method.

Results: Three PRLR SNPs were nominally associated with breast cancer: in premenopausal women, rs249537 (per-allele OR 1.39, 95% CI 1.07 - 1.82, P=0.0140); and in postmenopausal women, rs7718468 (per-allele OR 1.16, 95% CI 1.03 — 1.30, P=0.0137) and rs13436213 (per-allele OR 1.13 95% CI 1.01 — 1.26, P=0.0397). We examined serum prolactin levels by genotype for these three SNPs to determine whether the potential risk alleles were associated with increased circulating prolactin, but mean serum prolactin levels were similar by genotype in controls: rs249537 TT=3.83 ng/ml, CT=5.51 ng/ml, CC=5.50 ng/ml, P-trend=0.8381; rs7718468 CC=6.41 ng/ml, CT=6.86 ng/ml, TT=6.47 ng/ml, P-trend=0.5643; and rs13436213 AA=6.48 ng/ml, AG=6.52 ng/ml, GG=6.29 ng/ml, P-trend=0.4766. None of the nominal associations between PRLR genotypes and breast cancer risk were significant after adjusting for multiple comparisons (multiple comparison adjusted P-values: rs249537 P=0.4340; rs7718468 P=0.4340; rs13436213 P=0.8205). PRL SNPs were not associated with breast cancer risk in premenopausal or postmenopausal women. Discussion: Our data do not support an association between PRL or PRLR tag SNPs and breast cancer. Though some associations were nominally significant, these results may be due to random error and require further study. Furthermore, data do not support a relationship between riskassociated SNPs and differences in prolactin levels. Future research should focus on non-genetic factors that affect circulating prolactin levels.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-12-05.

Pathologic findings following false-positive screening tests for ovarian cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial

OBJECTIVE

In the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO), ovarian cancer screening with transvaginal ultrasound (TVU) and CA-125 produced a large number of false-positive tests. We examined relationships between histopathologic diagnoses, false-positive test group, and participant and screening test characteristics.

METHODS

The PLCO ovarian cancer screening arm included 39,105 women aged 55-74 years assigned to annual CA-125 and TVU. Histopathologic diagnoses from women with false-positive tests and subsequent surgery were reviewed in this analysis: all CA125+ (n=121); all CA125+/TVU+ (n=46); and a random sample of TVU+ (n=373). Demographic and ovarian cancer risk factor data were self-reported. Pathologic diagnoses were abstracted from surgical pathology reports. We compared participant characteristics and pathologic diagnoses by category of false-positive using Pearson χ2, Fisher's exact, or Wilcoxon-Mann-Whitney tests.

RESULTS

Women with a false-positive TVU were younger (P<0.001), heavier (P<0.001), and reported a higher frequency of prior hysterectomy (P<0.001). Serous cystadenoma, the most common benign ovarian diagnosis, was more frequent among women with TVU+ compared to CA-125+ and CA-125+/TVU+ (P<0.001). Benign non-ovarian findings were commonly associated with all false-positives, although more frequently with CA-125+ than TVU+ or CA-125+/TVU+ groups (P=0.019). Non-ovarian cancers were diagnosed most frequently among CA-125+ (P<0.001).

CONCLUSIONS

False-positive ovarian cancer screening tests were associated with a range of histopathologic diagnoses, some of which may be related to patient and screening test characteristics. Further research into the predictors of false-positive ovarian cancer screening tests may aid efforts to reduce false-positive results.

Epidemiological study of anti-HPV16/18 seropositivity and subsequent risk of HPV16 and -18 infections

BACKGROUND

Infection with human papillomavirus (HPV) 16 or HPV18 elicits an antibody response, but whether the elicited antibodies protect women against subsequent infection by a homologous HPV type compared with seronegative women is unknown.

METHODS

Study participants were women aged 18-25 years at enrollment in the control group of the ongoing National Cancer Institute-sponsored, community-based, randomized HPV16/18 Costa Rica Vaccine Trial. At enrollment, 2813 participants were negative for cervical HPV16 DNA and 2950 for HPV18 DNA. Women were interviewed regarding sociodemographic data and medical and health history. Medical and pelvic examinations were conducted for all consenting sexually experienced women. Serum samples taken at enrollment were tested for total HPV16/18 antibodies with a polyclonal enzyme-linked immunosorbent assay, and cervical specimens were tested for type-specific HPV DNA over 4 years of follow-up. Using Poisson regression, we compared rate ratios of newly detected cervical HPV16 or HPV18 infection among homologous HPV-seropositive and HPV-seronegative women, adjusting for age, education, marital status, lifetime number of sexual partners, and smoking.

RESULTS

There were 231 newly detected HPV16 infections during 5886 person-years among HPV16-seronegative women compared with 12 newly detected HPV16 infections during 581 person-years among HPV16-seropositive women with the highest HPV16 sero-levels. There were 136 newly detected HPV18 infections during 6352 person-years among HPV18-seronegative women compared with six new infections detected during 675 person-years among HPV18 seropositives with the highest sero-levels. After controlling for risk factors associated with newly detected HPV infection, having high HPV16 antibody titer at enrollment was associated with a reduced risk of subsequent HPV16 infection (women in the highest tertile of HPV16 antibody titers, adjusted rate ratio = 0.50, 95% confidence interval = 0.26 to 0.86 vs HPV16-seronegative women). Similarly, having high HPV18 antibody titer at enrollment was associated with a reduced risk of subsequent HPV18 infection (women in the highest tertile of HPV18 antibody titers, adjusted rate ratio = 0.36, 95% confidence interval = 0.14 to 0.76 vs HPV18-seronegative women).

CONCLUSION

In this study population, having high antibody levels against HPV16 and HPV18 following natural infection was associated with reduced risk of subsequent HPV16 and HPV18 infections.

Alcohol and endometrial cancer risk in the NIH-AARP diet and health study

Previous investigations have provided conflicting results regarding whether alcohol consumption affects endometrial cancer risk, although in many of these studies the highest category of alcohol intake examined was limited. Further, most were unable to resolve how alcohol associations are affected by beverage type, the presence of other endometrial cancer risk factors, or tumor characteristics. To address these issues, we prospectively evaluated the association between alcohol intake and incident endometrial cancer (n = 1,491) in a cohort of 114,414 US women enrolled in the NIH-AARP Diet and Health Study. We calculated relative risks (RR) and 95% confidence intervals (CI) using Cox proportional hazards regression. After adjustment for age, body mass index (BMI), smoking and other potential confounders, the multivariable RRs (and 95% CIs) compared with nondrinkers were 0.97 (0.87-1.09) for >0-<12 g of alcohol/day, 1.06 (0.87-1.31) for 12-<24 g/day and 0.93 (0.71-1.20) for ≥ 24 g/day (p trend = 0.90). There was, however, some suggestion of higher risks associated with alcohol consumption among lean women (BMI, <25) and users of menopausal hormone therapy, with significant interactions with both parameters (respective interaction p-values of 0.002 and 0.005). The relationship was also enhanced, albeit nonsignificantly so, for low grade cancers. Our results do not support that alcohol is a strong contributor to endometrial cancer risk, but slight risk increases may prevail among some users or for selected tumor characteristics.

Prolactin serum levels and breast cancer: relationships with risk factors and tumour characteristics among pre- and postmenopausal women in a population-based case-control study from Poland

Background:

Previous prospective studies have found an association between prolactin (PRL) levels and increased risk of breast cancer. Using data from a population-based breast cancer case–control study conducted in two cities in Poland (2000–2003), we examined the association of PRL levels with breast cancer risk factors among controls and with tumour characteristics among the cases.

Methods:

We analysed PRL serum levels among 773 controls without breast cancer matched on age and residence to 776 invasive breast cancer cases with available pretreatment serum. Tumours were centrally reviewed and prepared as tissue microarrays for immunohistochemical analysis. Breast cancer risk factors, assessed by interview, were related to serum PRL levels among controls using analysis of variance. Mean serum PRL levels by tumour characteristics are reported. These associations also were evaluated using polytomous logistic regression.

Results:

Prolactin levels were associated with nulliparity in premenopausal (P=0.05) but not in postmenopausal women. Associations in postmenopausal women included an inverse association with increasing body mass index (P=0.0008) and direct association with use of recent/current hormone therapy (P=0.0006). In case-only analyses, higher PRL levels were more strongly associated with lobular compared with ductal carcinoma among postmenopausal women (P=0.02). Levels were not different by tumour size, grade, node involvement or oestrogen receptor, progesterone receptor, or human epidermal growth factor receptor 2 status.

Conclusions:

Our analysis demonstrates that PRL levels are higher among premenopausal nulliparous as compared with parous women. Among postmenopausal women, levels were higher among hormone users and lower among obese women. These results may have value in understanding the mechanisms underlying several breast cancer risk factor associations.

Determinants of seropositivity among HPV-16/18 DNA positive young women

BACKGROUND

Not all women infected with HPV-16/18 have detectable levels of HPV-16/18 antibodies, those who seroconvert develop low antibody levels, and seroconversion occurs typically several months post-infection. We evaluated determinants of seropositivity among 646 women infected with HPV-16 and/or HPV-18.

METHODS

Data are from the enrollment visit of the NCI-sponsored Costa Rica HPV Vaccine Trial. Sera were tested for HPV-16/18 antibodies by ELISA; cervical specimens were tested for HPV DNA using HC2 and SPF10/LiPA25. Odds ratios (OR) and 95% confidence intervals (CI) were computed.

RESULTS

Among HPV-16/18 DNA positives, seropositivity was 63.0% and 57.5%, respectively. Among HPV-16 DNA positives, seropositivity increased with lifetime number of sexual partners (p-trend = 0.01). Women with abnormal cytology and/or high viral load had a 1.63-2.79-fold increase in the detection of antibodies compared to women with normal cytology/low viral load. Current users of oral contraceptives had a 1.88-fold (95%CI, 1.14-3.09) increased detection of antibodies and current users of injectables had a 3.38-fold (95%CI, 1.39-8.23) increased detection compared to never users. Among HPV-18 DNA positive women, seropositivity was associated with current oral contraceptive use (OR 2.47; 95%CI 1.08-5.65).

CONCLUSIONS

Factors associated with sustained HPV exposure (abnormal cytology, elevated HPV viral load, increasing lifetime partners) were predictive of HPV-16 seropositivity. Hormonal contraceptive use was associated with seropositivity suggesting an effect of hormones on immune responses to HPV. Patterns were less consistent for HPV-18. Follow up of incident HPV infections to evaluate seroconversion and their determinants is needed.

Subtyping of breast cancer by immunohistochemistry to investigate a relationship between subtype and short and long term survival: a collaborative analysis of data for 10,159 cases from 12 studies

BACKGROUND

Immunohistochemical markers are often used to classify breast cancer into subtypes that are biologically distinct and behave differently. The aim of this study was to estimate mortality for patients with the major subtypes of breast cancer as classified using five immunohistochemical markers, to investigate patterns of mortality over time, and to test for heterogeneity by subtype.

METHODS AND FINDINGS

We pooled data from more than 10,000 cases of invasive breast cancer from 12 studies that had collected information on hormone receptor status, human epidermal growth factor receptor-2 (HER2) status, and at least one basal marker (cytokeratin [CK]5/6 or epidermal growth factor receptor [EGFR]) together with survival time data. Tumours were classified as luminal and nonluminal tumours according to hormone receptor expression. These two groups were further subdivided according to expression of HER2, and finally, the luminal and nonluminal HER2-negative tumours were categorised according to expression of basal markers. Changes in mortality rates over time differed by subtype. In women with luminal HER2-negative subtypes, mortality rates were constant over time, whereas mortality rates associated with the luminal HER2-positive and nonluminal subtypes tended to peak within 5 y of diagnosis and then decline over time. In the first 5 y after diagnosis the nonluminal tumours were associated with a poorer prognosis, but over longer follow-up times the prognosis was poorer in the luminal subtypes, with the worst prognosis at 15 y being in the luminal HER2-positive tumours. Basal marker expression distinguished the HER2-negative luminal and nonluminal tumours into different subtypes. These patterns were independent of any systemic adjuvant therapy.

CONCLUSIONS

The six subtypes of breast cancer defined by expression of five markers show distinct behaviours with important differences in short term and long term prognosis. Application of these markers in the clinical setting could have the potential to improve the targeting of adjuvant chemotherapy to those most likely to benefit. The different patterns of mortality over time also suggest important biological differences between the subtypes that may result in differences in response to specific therapies, and that stratification of breast cancers by clinically relevant subtypes in clinical trials is urgently required.

Abstract 2779: Relationship of mammographic density with breast cancer subtypes

Background: Mammographic density (MD), a measure of the amount of radiologically dense breast tissue, is one of the strongest breast cancer risk factors. Studies have found that high MD increases risk for both estrogen receptor (ER)-negative and positive breast cancers, but data relating MD to breast cancer subtypes are limited.

Methods: We used data from the population-based Polish Breast Cancer Study to explore relationships between MD and breast cancer characteristics. This analysis includes 227 invasive breast cancers, which were available as frozen samples and used for mRNA and cytogenetic profiling, and fixed tissues, which were prepared as tissue microarrays for immunohistochemical analysis. Pre-treatment mammograms of the unaffected breast were retrieved for 184 (81%) cases ages 28-75 years. Craniocaudal views of digitized films were used to assess percent MD with Cumulus, a computer-assisted thresholding method. Analysis of variance (ANOVA) models were used to test the null hypothesis of no mean difference in MD between the breast cancer subtypes.

Results: Tumor subtypes were classified by key immunohistochemical markers as luminal A (ER+ and/or progesterone receptor (PR)+, human epidermal growth factor receptor-2 (HER2)-; n=129), luminal B (ER+ and/or PR+, HER2+; n=6), HER2-expressing (ER-, PR-, HER2+; n=13), basal-like (ER-, PR-, HER2-, cytokeratin 5+, and/or HER1+; n=23), and unclassified (negative for all five markers; n=8). Five cases did not have interpretable staining for all five markers and were excluded. MD values were approximately normally distributed. Preliminary ANOVA models revealed no differences in mean percent MD by tumor subtypes (p=0.29) as follows: luminal A, 27.5% (95% confidence interval (CI): 24.9-30.2); luminal B, 27.0% (95% CI: 14.8-39.2); HER2-expressing, 27.2% (95% CI: 18.9-35.5); basal-like, 24.6% (95% CI: 18.4-30.8); and unclassified, 15.7% (95% CI: 5.2-26.3). In analysis of covariance models adjusted for age there was marginal evidence of elevated MD with the HER2-expressing subtype (p=0.04), but we cannot exclude the possibility that this is a chance finding.

Conclusions: Our results do not provide strong support for an association between percent MD and breast cancer subtypes. To identify additional clues as to the biology underlying the MD-breast cancer relationship, ongoing analyses will relate MD to mRNA and cytogenetic profiles and data for protein expression via immunohistochemistry available for additional markers as previously reported.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2779.

Abstract 3762: Automated analysis of breast cancer tissue microarrays to investigate etiologic heterogeneity in the Breast Cancer Association Consortium

Background: Data suggest that breast cancer risk factor associations vary by tumor marker expression. However, individual studies often lack the power required to assess these relationships and pooled analyses are limited by non-standardized scoring of tumor markers. To address these limitations, the Breast Cancer Association Consortium is assessing whether automated image analysis of immunohistochemically stained tissue microarrays (TMAs) can permit standardized scoring of tumor markers.

Methods: TMA sections prepared in 10 case-control studies containing up to 9,298 breast cancers stained for estrogen receptor (ER); progesterone receptor (PR); human epidermal growth factor receptor 2 (HER 2); epidermal growth factor receptor (EGFR) and cytokeratin 5/6 (CK 5/6) were scanned as digital images. Automated algorithms were used to score markers in tumor cells using the Ariol system. We are analyzing consistency of automated scores within individual studies; between studies; and against visual reads.

Results: Preliminarily, distributions of automated scores were generally similar across different TMA blocks within a study; however isolated blocks yielded disparate results related to low or high intensity staining for a marker or the counterstain across the entire slide. Distributions of scores varied between studies, suggesting the need for study-specific cutpoints for negative vs. positive. Analysis of receiver operator characteristic curves comparing automated analysis to independently recorded visual reads in two studies demonstrated areas under the curves of 0.90 and 0.93 for tumors classified visually as ER+/PR+ and 0.91 and 0.88 for tumors scored visually as ER-/PR-. Cores scored as negative for EGFR or CK 5/6 by automated methods agreed well with visual scores, but many tumors scored as positive by automated analysis were negative by visual review, irrespective of ER / PR status. Thus, restricting analyses to ER-/PR- tumors (a subset of interest) reduced the number of discrepancies. Ongoing analyses are comparing automated and visual scores for all markers / studies and are assessing risk factor associations for breast cancer by tumor marker expression (negative vs. positive and strength of expression) based on automated scores.

Conclusions: Automated analysis of immunohistochemically stained TMAs of breast cancers may be useful in standardizing high throughout characterization of cancer markers in multicenter studies and in consortia, although additional methodologic work is needed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3762.

Abstract 861: Relationships of prolactin serum levels to breast cancer risk and tumor characteristics in a population-based case-control study from Poland

Background: Prolactin is a peptide hormone that is important in growth and development of the human breast. Prolactin also induces migration, proliferation, and survival of cancer cells in vitro and mammary gland tumorigenesis in animal models. Recent studies suggest that elevated serum prolactin levels are related to increased breast cancer risk, but confirmation and extension of these results are needed. Accordingly, we analyzed associations of serum prolactin levels with breast cancer risk using data from a population-based breast cancer case-control study conducted in Poland.

Methods: The Polish study included 2,386 consenting cases with pathologically confirmed breast cancer and 2,502 age and residency matched controls living in Warsaw and Lodz, Poland recruited during the years 2000 to 2003. Participation rates were 79% for cases and 69% for controls. This analysis included 773 cases and 776 controls with available serum and twofold representation of tumor in tissue microarrays. 70% of this study population was postmenopausal. Serum prolactin was measured by immunoassay at Quest Diagnostics. The overall CV for the prolactin serum assay was 99%. Detailed medical history and breast cancer risk factor information were obtained by interview. Tumor pathology data were collected via surgical pathology reports and independently reviewed in the U.S. Among controls, we assessed associations of prolactin levels with breast cancer risk factors using analysis of variance; case-control associations between breast cancer risk and prolactin levels (quartiles) were assessed by logistic regression.

Results: Among premenopausal controls, nulliparity was inversely associated with prolactin levels (p=0.05), whereas among postmenopausal women, current/recent use of combined hormone replacement therapy (p&lt;0.0001) and lower body mass index (BMI, p&lt;0.0001) were associated with higher prolactin levels. After adjustment for these and other known breast cancer risk factors, as well as for matching factors, elevated prolactin levels were significantly associated with postmenopausal breast cancer risk (OR=1.95; 95% CI 1.37-2.78, p&lt;0.0001), when comparing the highest quartile of prolactin levels to the lowest. Among premenopausal women, risk also was elevated for all levels of prolactin, but risks were not significant and did not increase in a monotonic pattern.

Conclusions: Prolactin levels are significantly associated with breast cancer risk factors and risk for postmenopausal breast cancer. Our results confirm and extend prior studies focused on circulating prolactin levels and human breast cancer risk. Analyses examining associations between prolactin and tumor subclassifications based on immunological staining using tumor tissue microarrays are ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 861.

Abstract 2850: Endometrial cancer and genetic variation in PTEN, PIK3CA, AKT1, MLH1, and MSH2: results and replication in two case-control studies

PTEN, PI3KCA, AKT, MLH1, and MSH2 likely influence endometrial carcinogenesis. PTEN regulates the crucial PI3K signaling pathway, which influences AKT, a serine-threonine kinase that affects apoptosis and cell proliferation; inadequate progesterone-stimulated apoptosis plus excess estrogen-driven proliferation are crucial for endometrial carcinoma. MLH1 and MSH2 influence DNA mismatch repair and microsatellite instability, which are often defective in endometrial cancers. We investigated common genetic variation in these genes among 417 cases and 407 matched controls from the population-based Poland Endometrial Case-control Study (PECS). We genotyped 76 tagging single nucleotide polymorphisms (tagSNPs) that were located in or within 10kb upstream or 5kb downstream of these genes, had a MAF&gt;=5% in various ethnic groups, and were not already represented by another tagSNP at a linkage disequilibrium of r2&gt;=0.80. Genotyping was performed on an Illumina Custom Infinium iSelect assay that includes 29,289 SNPs in 1316 genes. For individual SNPs, we used unconditional logistic regression, adjusted for age and site, to generate odds ratios (ORs) and 95% confidence intervals (CIs) for heterozygous genotypes, minor homozygous genotypes, and trends for number of minor alleles under log-additive inheritance. Only 1 tagSNP, rs2677764 in PIK3CA, was statistically significantly associated with endometrial cancer. Compared with a referent group of CC, the ORs (95% CIs) were 1.47 (1.03-2.10) for CT and 1.56 (0.43-5.60) for TT. The OR for the trend was 1.42 (95% CI, 1.03-1.95; P=0.03). We chose extended blocks as the main haplotype analysis, used an E-M algorithm to simultaneously reconstruct haplotypes and estimate ORs, and used a sequential-scan method to identify statistically significant haplotypes. All global p-values for the 25 haplotypes observed in at least 5% of cases and controls were null. One haplotype in PIK3CA was significantly associated with endometrial cancer (OR=1.39. 95% CI, 1.00-1.93). We also used adaptive rank truncated product (ARTP) methods to detect gene associations, but none were statistically significant. To further assess the validity of the association with rs2677764, we genotyped that SNP in a 2nd study, the SEARCH study in the UK, with 1141 endometrial cancer cases and 2275 controls. For rs2677764, the ORs (95% CIs) were 0.93 (0.77-1.13) for CT, 1.27 (0.68-2.39) for TT, and 0.98 (0.82-1.17) for the trend test. In a fixed-effect meta-analysis combining PECS and SEARCH, rs2677764 was not associated with endometrial cancer: OR=1.15 (95% CI, 0.80-1.66; P=0.45 for trend test). The absence of replication in SEARCH of an association with rs2677764 in PIK3CA in PECS and the null results from haplotype and ARTP analyses indicate that these common genetic variations in PTEN, PI3KCA, AKT, MLH1, and MSH2 do not substantially affect endometrial cancer risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2850.

Assessment of automated image analysis of breast cancer tissue microarrays for epidemiologic studies

BACKGROUND

A major challenge in studies of etiologic heterogeneity in breast cancer has been the limited throughput, accuracy, and reproducibility of measuring tissue markers. Computerized image analysis systems may help address these concerns, but published reports of their use are limited. We assessed agreement between automated and pathologist scores of a diverse set of immunohistochemical assays done on breast cancer tissue microarrays (TMA).

METHODS

TMAs of 440 breast cancers previously stained for estrogen receptor (ER)-alpha, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), ER-beta, and aromatase were independently scored by two pathologists and three automated systems (TMALab II, TMAx, and Ariol). Agreement between automated and pathologist scores of negative/positive was measured using the area under the receiver operating characteristics curve (AUC) and weighted kappa statistics for categorical scores. We also investigated the correlation between immunohistochemical scores and mRNA expression levels.

RESULTS

Agreement between pathologist and automated negative/positive and categorical scores was excellent for ER-alpha and PR (AUC range = 0.98-0.99; kappa range = 0.86-0.91). Lower levels of agreement were seen for ER-beta categorical scores (AUC = 0.99-1.0; kappa = 0.80-0.86) and both negative/positive and categorical scores for aromatase (AUC = 0.85-0.96; kappa = 0.41-0.67) and HER2 (AUC = 0.94-0.97; kappa = 0.53-0.72). For ER-alpha and PR, there was a strong correlation between mRNA levels and automated (rho = 0.67-0.74) and pathologist immunohistochemical scores (rho = 0.67-0.77). HER2 mRNA levels were more strongly correlated with pathologist (rho = 0.63) than automated immunohistochemical scores (rho = 0.41-0.49).

CONCLUSIONS

Automated analysis of immunohistochemical markers is a promising approach for scoring large numbers of breast cancer tissues in epidemiologic investigations. This would facilitate studies of etiologic heterogeneity, which ultimately may allow improved risk prediction and better prevention approaches.

A population-based prospective study of carcinogenic human papillomavirus variant lineages, viral persistence, and cervical neoplasia

Human papillomavirus (HPV) types differ profoundly in cervical carcinogenicity. For the most carcinogenic type HPV16, variant lineages representing further evolutionary divergence also differ in cancer risk. Variants of the remaining 10 to 15 carcinogenic HPV types have not been well studied. In the first prospective, population-based study of HPV variants, we explored whether, on average, the oldest evolutionary branches within each carcinogenic type predicted different risks of >2-year viral persistence and/or precancer and cancer [cervical intraepithelial neoplasia grade 3+ (CIN3+)]. We examined the natural history of HPV variants in the 7-year, 10,049-woman Guanacaste Cohort Study, using a nested case-control design. Infections were assigned to a variant lineage determined by phylogenetic parsimony methods based on URR/E6 sequences. We used the Fisher's combination test to evaluate significance of the risk associations, cumulating evidence across types. Globally, for HPV types including HPV16, the P value was 0.01 for persistence and 0.07 for CIN3+. Excluding HPV16, the P values were 0.04 and 0.37, respectively. For HPV16, non-European viral variants were significantly more likely than European variants to cause persistence [odds ratio (OR), 2.6; P = 0.01] and CIN3+ (OR, 2.4; P = 0.004). HPV35 and HPV51 variant lineages also predicted CIN3+. HPV variants generally differ in risk of persistence. For some HPV types, especially HPV16, variant lineages differ in risk of CIN3+. The findings indicate that continued evolution of HPV types has led to even finer genetic discrimination linked to HPV natural history and cervical cancer risk. Larger viral genomic studies are warranted, especially to identify the genetic basis for HPV16's unique carcinogenicity.

Molecular pathology in epidemiologic studies: a primer on key considerations

The development of molecular pathologic components in epidemiologic studies offers opportunities to relate etiologic factors to specific tumor types, which in turn may allow the development of better overall risk prediction and provide clues about mechanisms that mediate risk factors. In addition, this research may help identify or validate tissue biomarkers related to prognosis and prediction of treatment responses. In this mini review, we highlight specific considerations related to the incorporation of pathology in epidemiologic studies, using breast cancer research as a model. Issues related to ensuring the representativeness of cases for which research tissue is available and understanding limitations resulting from variable procedures for tissue collection, fixation, and processing are discussed. The growing importance of molecular pathology in clinical medicine has led to increased emphasis on optimized tissue preparation, which should enhance this type of research. In addition, the availability of new technologies including tissue microarrays, image scanning, and automated analysis to achieve high-throughput standardized assessment of immunohistochemical markers, and potentially other assays, is enabling consistent scoring of a growing list of markers in large studies. Concurrently, methodologic research to extend the range of assays that can be done on fixed tissues is expanding possibilities for molecular pathologic studies in epidemiologic research.

Association between a germline OCA2 polymorphism at chromosome 15q13.1 and estrogen receptor-negative breast cancer survival

BACKGROUND

Traditional prognostic factors for survival and treatment response of patients with breast cancer do not fully account for observed survival variation. We used available genotype data from a previously conducted two-stage, breast cancer susceptibility genome-wide association study (ie, Studies of Epidemiology and Risk factors in Cancer Heredity [SEARCH]) to investigate associations between variation in germline DNA and overall survival.

METHODS

We evaluated possible associations between overall survival after a breast cancer diagnosis and 10 621 germline single-nucleotide polymorphisms (SNPs) from up to 3761 patients with invasive breast cancer (including 647 deaths and 26 978 person-years at risk) that were genotyped previously in the SEARCH study with high-density oligonucleotide microarrays (ie, hypothesis-generating set). Associations with all-cause mortality were assessed for each SNP by use of Cox regression analysis, generating a per rare allele hazard ratio (HR). To validate putative associations, we used patient genotype information that had been obtained with 5' nuclease assay or mass spectrometry and overall survival information for up to 14 096 patients with invasive breast cancer (including 2303 deaths and 70 019 person-years at risk) from 15 international case-control studies (ie, validation set). Fixed-effects meta-analysis was used to generate an overall effect estimate in the validation dataset and in combined SEARCH and validation datasets. All statistical tests were two-sided.

RESULTS

In the hypothesis-generating dataset, SNP rs4778137 (C>G) of the OCA2 gene at 15q13.1 was statistically significantly associated with overall survival among patients with estrogen receptor-negative tumors, with the rare G allele being associated with increased overall survival (HR of death per rare allele carried = 0.56, 95% confidence interval [CI] = 0.41 to 0.75, P = 9.2 x 10(-5)). This association was also observed in the validation dataset (HR of death per rare allele carried = 0.88, 95% CI = 0.78 to 0.99, P = .03) and in the combined dataset (HR of death per rare allele carried = 0.82, 95% CI = 0.73 to 0.92, P = 5 x 10(-4)).

CONCLUSION

The rare G allele of the OCA2 polymorphism, rs4778137, may be associated with improved overall survival among patients with estrogen receptor-negative breast cancer.

Performance of common genetic variants in breast-cancer risk models

BACKGROUND

Genomewide association studies have identified multiple genetic variants associated with breast cancer. The extent to which these variants add to existing risk-assessment models is unknown.

METHODS

We used information on traditional risk factors and 10 common genetic variants associated with breast cancer in 5590 case subjects and 5998 control subjects, 50 to 79 years of age, from four U.S. cohort studies and one case-control study from Poland to fit models of the absolute risk of breast cancer. With the use of receiver-operating-characteristic curve analysis, we calculated the area under the curve (AUC) as a measure of discrimination. By definition, random classification of case and control subjects provides an AUC of 50%; perfect classification provides an AUC of 100%. We calculated the fraction of case subjects in quintiles of estimated absolute risk after the addition of genetic variants to the traditional risk model.

RESULTS

The AUC for a risk model with age, study and entry year, and four traditional risk factors was 58.0%; with the addition of 10 genetic variants, the AUC was 61.8%. About half the case subjects (47.2%) were in the same quintile of risk as in a model without genetic variants; 32.5% were in a higher quintile, and 20.4% were in a lower quintile.

CONCLUSIONS

The inclusion of newly discovered genetic factors modestly improved the performance of risk models for breast cancer. The level of predicted breast-cancer risk among most women changed little after the addition of currently available genetic information.

Longitudinal study of human papillomavirus persistence and cervical intraepithelial neoplasia grade 2/3: critical role of duration of infection

BACKGROUND

The natural history of human papillomavirus (HPV) infections in older women is critical for preventive strategies, including vaccination and screening intervals, but is poorly understood. In a 7-year population-based cohort study in Guanacaste, Costa Rica, we examined whether women's age and the duration of carcinogenic HPV infections influenced subsequent persistence of infection and risk of cervical intraepithelial neoplasia grade 2 (CIN 2) or worse disease.

METHODS

At enrollment, of the 9466 participants eligible for pelvic examination, 9175 were screened for cervical neoplasia using multiple methods; those with CIN 2 or worse disease were censored and treated. Participants at low risk of CIN 2 or worse (n = 6029) were rescreened at 5-7 years (passively followed), whereas higher-risk participants (n = 2115) and subsets of low-risk women (n = 540) and initially sexually inactive women (n = 410) were rescreened annually or semiannually (actively followed) for up to 7 years. HPV testing was done using a polymerase chain reaction-based method. We determined, by four age groups (18-25, 26-33, 34-41, and > or =42 years), the proportion of prevalent infections (found at baseline) and newly detected infections (first found during follow-up) that persisted at successive 1-year time points and calculated absolute risks of CIN 2 and CIN grade 3 (CIN 3) or worse during follow-up. P values are two-sided.

RESULTS

Regardless of the woman's age, newly detected infections were associated with very low absolute risks of persistence, CIN 2, or worse disease. For newly detected infections, the rate of progression to CIN 2+ (or CIN 3+), after 3 years of follow-up, was not higher for women aged 34 years and older than for younger women. Moreover, rates of newly detected infections declined sharply with age (in the actively followed group, at ages 18-25, 26-33, 34-41, and > or =42 years, rates were 35.9%, 30.6%, 18.1%, and 13.5%, respectively; P < .001). Among prevalent infections, persistent infections among older women (> or =42 years) was higher than that among younger age groups or new infections at any age (P < .01 for comparison of eight groups). Most (66 of 85) CIN 2 or worse detected during follow-up was associated with prevalent infections. Only a small subset (25 of 1128) of prevalent infections persisted throughout follow-up without apparent CIN 2 or worse.

CONCLUSIONS

The rate of new infections declines with age, and new infections typically do not progress to CIN 2 or worse disease in older women; thus, overall potential benefit of prophylactic vaccination or frequent HPV screening to prevent or detect new carcinogenic HPV infections at older ages is low.

Common genetic variants and risk for HPV persistence and progression to cervical cancer

HPV infrequently persists and progresses to cervical cancer. We examined host genetic factors hypothesized to play a role in determining which subset of individuals infected with oncogenic human papillomavirus (HPV) have persistent infection and further develop cervical pre-cancer/cancer compared to the majority of infected individuals who will clear infection.

We evaluated 7140 tag single nucleotide polymorphisms (SNPs) from 305 candidate genes hypothesized to be involved in DNA repair, viral infection and cell entry in 416 cervical intraepithelial neoplasia 3 (CIN3)/cancer cases, 356 HPV persistent women (median: 25 months), and 425 random controls (RC) from the 10,049 women Guanacaste Costa Rica Natural History study. We used logistic regression to compute odds ratios and p-trend for CIN3/cancer and HPV persistence in relation to SNP genotypes and haplotypes (adjusted for age). We obtained pathway and gene-level summary of associations by computing the adaptive combination of p-values. Genes/regions statistically significantly associated with CIN3/cancer included the viral infection and cell entry genes 2′,5′ oligoadenylate synthetase gene 3 (OAS3), sulfatase 1 (SULF1), and interferon gamma (IFNG); the DNA repair genes deoxyuridine triphosphate (DUT), dosage suppressor of mck 1 homolog (DMC1), and general transcription factor IIH, polypeptide 3 (GTF2H4); and the EVER1 and EVER2 genes (p<0.01). From each region, the single most significant SNPs associated with CIN3/cancer were OAS3 rs12302655, SULF1 rs4737999, IFNG rs11177074, DUT rs3784621, DMC1 rs5757133, GTF2H4 rs2894054, EVER1/EVER2 rs9893818 (p-trends≤0.001). SNPs for OAS3, SULF1, DUT, and GTF2H4 were associated with HPV persistence whereas IFNG and EVER1/EVER2 SNPs were associated with progression to CIN3/cancer. We note that the associations observed were less than two-fold. We identified variations DNA repair and viral binding and cell entry genes associated with CIN3/cancer. Our results require replication but suggest that different genes may be responsible for modulating risk in the two critical transition steps important for cervical carcinogenesis: HPV persistence and disease progression.

Absolute risk of endometrial carcinoma during 20-year follow-up among women with endometrial hyperplasia

PURPOSE The severity of endometrial hyperplasia (EH)-simple (SH), complex (CH), or atypical (AH)-influences clinical management, but valid estimates of absolute risk of clinical progression to carcinoma are lacking. Materials and METHODS We conducted a case-control study nested in a cohort of 7,947 women diagnosed with EH (1970-2002) at one prepaid health plan who remained at risk for at least 1 year. Patient cases (N = 138) were diagnosed with carcinoma, on average, 6 years later (range, 1 to 24 years). Patient controls (N = 241) were matched to patient cases on age at EH, date of EH, and duration of follow-up, and they were counter-matched to patient cases on EH severity. After we independently reviewed original slides and medical records of patient controls and patient cases, we combined progression relative risks (AH v SH, CH, or disordered proliferative endometrium [ie, equivocal EH]) from the case-control analysis with clinical censoring information (ie, hysterectomy, death, or left the health plan) on all cohort members to estimate interval-specific (ie, 1 to 4, 5 to 9, and 10 to 19 years) and cumulative (ie, through 4, 9, and 19 years) progression risks. Results For nonatypical EH, cumulative progression risk increased from 1.2% (95% CI, 0.6% to 1.9%) through 4 years to 1.9% (95% CI, 1.2% to 2.6%) through 9 years to 4.6% (95% CI, 3.3% to 5.8%) through 19 years after EH diagnosis. For AH, cumulative risk increased from 8.2% (95% CI, 1.3% to 14.6%) through 4 years to 12.4% (95% CI, 3.0% to 20.8%) through 9 years to 27.5% (95% CI, 8.6% to 42.5%) through 19 years after AH. CONCLUSION Cumulative 20-year progression risk among women who remain at risk for at least 1 year is less than 5% for nonatypical EH but is 28% for AH.