bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical Activity in Different Periods of Life and the Risk of Breast Cancer: The Norwegian-Swedish Women's Lifestyle and Health Cohort Study
Authors: Margolis Karen L. , Mucci Lorelei , Braaten Tonje , Kumle Merethe , Trolle Lagerros Ylva , Adami Hans-Olov , Lund Eiliv , Weiderpass Elisabete 
Published: June 2022

Abstract
Background: Physical activity has been found to be associated with decreased risk of breast cancer in postmenopausal women in the majority of epidemiologic studies, but the association is inconsistent in premenopausal women.
Methods: We studied the effect of physical activity at various ages on the incidence of breast cancer in 99,504 women from 30 to 49 years of age at enrollment in the Women's Lifestyle and Health Study, a prospective population-based cohort study in Norway and Sweden. Physical activity level on an ordinal scale at age 14, age 30, and age at enrollment, participation in competitive sports, as well as information on other covariates was obtained using a self-administered questionnaire. Complete follow-up with data on incident invasive breast cancer and mortality was collected by linkage to national registries. The relation between physical activity and time to breast cancer development was assessed using Cox proportional hazard models, controlling for potential confounders.
Results: During an average 9.1 years of follow-up, there were 1,166 incident breast cancer cases. The mean age of the women was 41 years at enrollment, and the mean age at breast cancer diagnosis was 48 years. Compared to inactive women, women with higher levels of physical activity at enrollment had a similar risk of incident breast cancer (adjusted relative risk, 1.24 for vigorous activity compared with no activity; 95% CI, 0.85-1.82). Physical activity at age 30 or at age 14 also did not afford any significant protection from breast cancer, nor did a consistently high level of activity from younger ages to enrollment.
Conclusions: We did not find evidence of a protective effect of physical activity on breast cancer risk in this group of primarily premenopausal women.
The Role of Tomato Products and Lycopene in the Prevention of Prostate Cancer: A Meta-Analysis of Observational Studies
Authors: Etminan Mahyar , Takkouche Bahi , Caamaño-Isorna Francisco 
Published: June 2022

Abstract
Purpose: To determine whether intake of tomato products reduces the risk of prostate cancer using a meta-analysis. Methods: We systematically searched MEDLINE and EMBASE and contacted authors to identify potential studies. Log relative risks (RRs) were weighed by the inverse of their variances to obtain a pooled estimate with its 95% confidence interval (CI). Logistic regression and Poisson regression analyses were used to determine the effect produced by a daily intake of one serving of tomato product. Results: Eleven case-control studies and 10 cohort studies or nested case-control studies presented data on the use of tomato, tomato products, or lycopene and met our inclusion criteria. Compared with nonfrequent users of tomato products (1st quartile of intake), the RR of prostate cancer among consumers of high amounts of raw tomato (5th quintile of intake) was 0.89 (95% CI 0.80–1.00). For high intake of cooked tomato products, this RR was 0.81 (95% CI 0.71–0.92). The RR of prostate cancer related to an intake of one serving/day of raw tomato (200 g) was 0.97 (95% CI 0.85–1.10) for the case-control studies and 0.78 (95% CI 0.66–0.92) for cohort studies. Conclusion: Our results show that tomato products may play a role in the prevention of prostate cancer. However, this effect is modest and restricted to high amounts of tomato intake. Further research is needed to determine the type and quantity of tomato products with respect to their role in preventing prostate cancer.
Decreased Retinoid X Receptor-α Protein Expression in Basal Cells Occurs in the Early Stage of Human Prostate Cancer Development
Authors: Mao Gloria E. , Reuter Victor E. , Cordon-Cardo Carlos , Dalbagni Guido , Scher Howard I. , deKernion Jean B. , Zhang Zuo-Feng , Rao Jianyu 
Published: June 2022

AbstractThe development of prostatic intraepithelial neoplasia (PIN)-like lesions in the prostate-specific retinoid X receptor-α (RXRα) null mouse suggests that RXRα may protect against neoplasia. The purpose of this study was to characterize RXRα protein expression in human prostate to determine if RXRα is altered in early stages of tumor progression. Immunohistochemistry with anti-RXRα antibody was performed on 138 fresh frozen prostate specimens collected from 27 noncarcinomatous prostates and 111 radical prostatectomy samples of prostate adenocarcinoma (CA). The RXRα signal intensity was scored using a scale of 0–3. In normal glands, RXRα was expressed strongly in basal cells and only weakly in secretory epithelial cells. This finding was confirmed by double immunofluorescence labeling of RXRα and Keratin-903, a basal cell marker, followed by confocal microscopic examination. In basal cells, a gradual decrease of RXRα expression was noted from normal glands of noncarcinomatous prostate (3.0 ± 0) to “normal” glands distant to CA (2.13 ± 0.44) to “normal” glands adjacent to CA (1.25 ± 0.53) and high-grade PIN (0.56 ± 0.58). While nearly all “normal” glands from 138 specimens were positive for RXRα in basal cells, only 48% (13 of 27) of the high-grade PIN glands appeared positive. Moreover, basal cell expression of RXRα in “normal” tissue was less in specimens with poorly differentiated tumor (Gleason score ≥ 8; 1.83 ± 0.36) compared with well-differentiated tumor (Gleason score &lt; 6; 2.35 ± 0.34; P = 0.04). Thus, a decrease of RXRα in the basal cells may serve as a marker for prostate CA-associated field change, which may represent an early event in the prostate carcinogenic process. These findings suggest that chemoprevention strategies with retinoids may be most effective if applied during the early stages of transformation.
Insulin-Like Growth Factors, Insulin-Like Growth Factor-Binding Proteins, and Endometrial Cancer in Postmenopausal Women: Results from a U.S. Case-Control Study
Authors: Lacey James V. , Potischman Nancy , Madigan M. Patricia , Berman Michael L. , Mortel Rodrigue , Twiggs Leo B. , Barrett Rolland J. , Wilbanks George D. , Lurain John R. , Fillmore Capri-Mara , Sherman Mark E. , Brinton Louise A. 
Published: June 2022

Abstract
Objective: To assess whether circulating insulin-like growth factor-1 (IGF-1), IGF-2, insulin-like growth factor-binding protein-1 (IGFBP-1), or IGFBP-3 were associated with endometrial cancer in postmenopausal women. Study Design: Between 1987 and 1990, we conducted a case-control study of 405 women with endometrial cancer and 297 matched population-based controls. This analysis included 174 postmenopausal cases and 136 controls. Results: In logistic regression models adjusted for potential confounders, higher IGF-1 levels were not positively associated with endometrial cancer: odds ratio (OR) for the highest tertile versus the lowest tertile = 0.63, 95% confidence interval (CI) = 0.30–1.32. Endometrial cancer was inversely associated with IGF-2 (OR for the highest tertile = 0.35, 95% CI = 0.18–0.69) and IGFBP-3 (OR for the highest tertile = 0.40, 95% CI = 0.21–0.77), and not associated with IGFBP-1. Conclusion: Serum IGF-1, IGF-2, and IGFBP-3, but not IGFBP-1, were inversely associated with endometrial cancer in postmenopausal women. These associations and the potential role of the IGF system in endometrial proliferation and carcinogenesis warrant further research.
Colorectal Cancer Screening Adherence in a General Population
Authors: Yeazel Mark W. , Church Timothy R. , Jones Resa M. , Kochevar Laura K. , Watt Gavin D. , Cordes Jill E. , Engelhard Deborah , Mongin Steven J. 
Published: June 2022

Abstract
Background: This article describes the self-reported colorectal cancer (CRC) screening adherence rates of adults, aged 50 years and older, living in five nonurban Minnesota counties. Methods: During the year 2000, 1693 eligible respondents, aged 50 years and older, from a randomly selected sample completed a survey assessing CRC screening adherence (∼86.3% response). The survey allowed differentiation between the four CRC screening modalities but did not differentiate between screening and diagnostic testing. Adjustment for nonresponse was performed using a version of Horvitz-Thompson weighting accounting for unknown eligibility. Results: 24.5% of respondents had a fecal occult blood test within 1 year of the survey, 33.8% had flexible sigmoidoscopy within 5 years, 29.3% had a colonoscopy within 10 years, and 13.7% had a barium enema within the last 5 years. Overall, 55.3% of respondents reported testing by any modality; thus, 44.7% were not adherent to screening guidelines. Conclusions: This study improves on previous attempts to characterize CRC screening adherence by assessing all four modalities of screening as recommended by current screening guidelines, by focusing on nonadherence, and by rigorously accounting for nonresponse. This study confirms that nearly half of the population remains unscreened by any method.
Loss of Antigenicity in Stored Sections of Breast Cancer Tissue Microarrays
Authors: Fergenbaum Jennifer H. , Garcia-Closas Montserrat , Hewitt Stephen M. , Lissowska Jolanta , Sakoda Lori C. , Sherman Mark E. 
Published: June 2022

Abstract
Immunohistochemical characterization of tumor tissues in epidemiological studies is a promising approach to identify breast cancer subtypes with distinct etiology. The recent development of the tissue microarray (TMA) technique allows for standardized, rapid, and cost-effective immunohistochemical characterization of many cases, which is critical in epidemiological studies. Sectioning paraffin blocks at different times results in loss of material, which can be reduced by preparing many sections each time a block is cut. However, data suggest that staining intensity declines in whole sections prepared from conventional paraffin blocks with storage time, resulting in false-negative results. This problem would be accentuated in TMAs because of the limited tissue representation of each case. To evaluate this concern, we prepared a single TMA block from 125 invasive breast carcinomas collected in a population-based case-control study conducted in Poland and compared estrogen receptor (ER-α), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression in sections cut and stored for 6 months at room temperature with sections cut from the same TMA block and stained on the same day. Percentage of positive cases for stored versus fresh sections was similar for ER (59.0%) but significantly higher in fresh sections for PR (56.3% versus 64.1%, P = 0.01) and HER2 (45.5% versus 64.4%, P &lt; 0.001). Among cases positive in both stored and fresh sections, the median percentage of immunoreactive cells was significantly reduced and the staining intensity was consistently lower in stored compared with fresh sections. We conclude that loss of immunoreactivity is an important problem in TMAs of breast cancer. Improved methods for sectioning TMAs and storing tissue sections aimed at reducing loss of immunoreactivity are critical for the use of TMAs in epidemiological studies.
Population-Based Case-Control Study of CYP11A Gene Polymorphism and Breast Cancer Risk
Authors: Zheng Wei , Gao Yu-Tang , Shu Xiao-Ou , Wen Wanqing , Cai Qiuyin , Dai Qi , Smith Jeffrey R. 
Published: June 2022

Abstract
The CYP11A gene encodes the cholesterol side-chain cleavage enzyme (P450scc) that catalyzes the first and rate-limiting step for the biosynthesis of sex hormones. A pentanucleotide repeat [(TAAAA)n] polymorphism in the 5′ of the CYP11A gene has been reported to be related to the risk of polycystic ovary syndrome, an inherited endocrine disorder characterized by hyperandrogenemia. We investigated the association of this polymorphism with breast cancer risk in a population-based case-control study conducted among Chinese women in Shanghai. Genotype assays were completed for 1015 incident breast cancer cases and 1082 community controls. Three common alleles with 4, 6, or 8 TAAAA repeats were identified in the study population. The frequency of the 8 repeat allele was more common in cases (12.6%) than controls (8.5%) (odds ratio = 1.6, 95% confidence interval = 1.3–1.9; P &lt; 0.0001). Compared to subjects who did not carry this allele, adjusted odds ratios were 1.5 (95% confidence interval = 1.2–1.9) and 2.9 (1.3–6.7) (P for trend, &lt;0.001), respectively, for those who carried one and two copies of this allele. This positive association was observed in both pre- and postmenopausal women and all strata defined by major breast cancer risk factors, including years of menstruation, body mass index, and waist-to-hip ratio. The results from this study indicate that the TAAAA repeat polymorphism near the promoter region of the CYP11A gene may be an important susceptibility factor for breast cancer risk.
Physical Activity and Risk of Ovarian Cancer: A Prospective Cohort Study in the United States
Authors: Hannan Lindsay M. , Leitzmann Michael F. , Lacey James V. , Colbert Lisa H. , Albanes Demetrius , Schatzkin Arthur , Schairer Catherine 
Published: June 2022

Abstract
Increased physical activity may lower the risk of ovarian cancer by reducing the frequency of ovulation, decreasing body fat, or diminishing chronic inflammation. Previous epidemiological studies examining the association between physical activity and risk of ovarian cancer have been inconsistent. We investigated the association of physical activity with ovarian cancer in a prospective cohort of 27,365 individuals from the Breast Cancer Detection Demonstration Project. During 227,045 person-years of follow-up, 121 cases of ovarian cancer were ascertained. Usual physical activity during the past year was assessed by a self-administered questionnaire. After adjusting for potential risk factors for ovarian cancer, the relative risks (95% confidence intervals) across increasing quintiles of total physical activity were 1.0, 0.73 (0.43–1.25), 0.84 (0.50–1.40), 0.56 (0.31–1.00), and 0.70 (0.41–1.21), respectively (P for trend = 0.13). In this prospective cohort study among U.S. women, we found no overall significant association between physical activity and risk of ovarian cancer, although the results are suggestive of an inverse association.
Urinary Excretion of Flavonoids Reflects Even Small Changes in the Dietary Intake of Fruits and Vegetables
Authors: Brevik Asgeir , Rasmussen Salka Elbøl , Drevon Christian A. , Andersen Lene Frost 
Published: June 2022

Abstract
Background: Due to the random and systematic measurement errors associated with current dietary assessment instruments, there is a need to develop more objective methods of measuring the intake of foods of importance to human health. Objective: The purpose of this study was to test whether urinary excretion of flavonoids could be used to identify subjects who are meeting Norwegian recommendations for fruit and vegetable intake (5 servings per day) from individuals who are consuming the national average amount of fruits and vegetables (2 servings per day). Design: Twenty-four-hour urine samples were collected in a strict crossover controlled feeding study. Forty healthy subjects (19–34 years) were included in the study. After a 1-week run-in period, one group was given a controlled diet that included 2 servings (300 g) of fruits and vegetables daily for 14 days, while the other group was given a diet containing 5 servings (750 g) per day. Following a 2-week washout and a 1 week run-in period, the regimens were switched between the groups. Results: An increased intake of mixed fruits and vegetables from 2 to 5 servings per day significantly enhanced urinary excretion of eriodictyol, naringenin, hesperetin, quercetin, kaempferol, isorhamnetin, and tamarixetin. The citrus flavonoids naringenin and hesperetin showed a steep dose-response relationship to dietary intake of fruits and vegetables, whereas the association to eriodictyol, quercetin, kaempferol, isorhamnetin, and tamarixetin was more moderate. Conclusion: The present study indicates that urinary excretion of dietary flavonoids may be used to assess changes of mixed fruit and vegetable intake corresponding to an increase from the present national intake in Norway to the recommended amount of 5 servings of fruits and vegetables daily.
Influence of CYP1A1, GSTM1, GSTT1, and NQO1 Genotypes and Cumulative Smoking Dose on Lung Cancer Risk in a Swedish Population
Authors: Alexandrie Anna-Karin , Nyberg Fredrik , Warholm Margareta , Rannug Agneta 
Published: June 2022

Abstract
The major identified risk factor for lung cancer is tobacco smoking. We identified previously the possible modifying influence of CYP1A1 and GSTM1 polymorphisms on lung cancer risk in a Swedish population. The present study, extended by several study subjects and with analyses for polymorphisms in GSTT1 and NQO1, includes 524 lung cancer cases and 530 control subjects. No evidence for an influence of genetic polymorphisms in CYP1A1, GSTM1, GSTT1, and NQO1 on lung cancer risk overall was found. In smokers, there was, however, a suggestion that the variant CYP1A1 and NQO1 genotypes may confer an increased risk for squamous cell carcinoma. In ever smokers, the homozygously deleted GSTM1 (GSTM1*O/*O) genotype was significantly associated with increased risk of small cell carcinoma (adjusted odds ratio 2.72, 95% confidence interval 1.32-5.90). The risks noted for the variant CYP1A1 genotypes and the GSTM1*O/*O genotype seemed to be restricted to light smokers. The GSTT1*O/*O genotype also appeared to be a possible risk factor in light smokers, whereas, in heavy smokers, this genotype was associated with decreased risk for lung cancer overall (odds ratio 0.36, 95% confidence interval 0.13-0.99). Due to the multiple comparisons made, we cannot exclude the possibility that some of these associations may represent chance findings.
Epidemiology of Urinary Melatonin in Women and Its Relation to Other Hormones and Night Work
Authors: Schernhammer Eva S. , Rosner Bernard , Willett Walter C. , Laden Francine , Colditz Graham A. , Hankinson Susan E. 
Published: June 2022

Abstract
Objective: Light exposure during night work suppresses melatonin production, and night work has been associated with an increased cancer risk. There is little information, however, about the interrelationships of night work, urinary melatonin levels, and levels of plasma steroid hormones in women. Method: We examined the reproducibility of morning urinary measurements of 6-sulfatoxymelatonin over a 3-year period in 80 premenopausal women. We assessed correlations between average urinary melatonin and plasma steroid hormone levels and evaluated potential associations between night work and hormone levels, using current and long-term shift work information from two large, prospective cohorts, the Nurses' Health Study cohorts. Results: The intraclass correlation for creatinine-adjusted 6-sulfatoxymelatonin was 0.72 (95% confidence interval, 0.65, 0.82). We found significantly increased levels of estradiol after longer durations of night work (geometric mean levels of estradiol, 8.8 pg/mL for women who never worked night shifts versus 10.1 pg/mL for women who worked 15 or more years of night shifts; P for trend = 0.03). We observed a significant inverse association between increasing number of nights worked within the 2 weeks preceding urine collection and urinary melatonin levels (r = −0.30, P = 0.008), but no association of recent night work with estradiol (r = 0.10, P = 0.41). Conclusion: A single morning urinary melatonin measurement is a reasonable marker for long-term melatonin levels among premenopausal women. Women who work on rotating night shifts seem to experience changes in hormone levels that may be associated with the increased cancer risk observed among night-shift workers.
Manganese Superoxide Dismutase Polymorphism, Plasma Antioxidants, Cigarette Smoking, and Risk of Breast Cancer
Authors: Tamimi Rulla M. , Hankinson Susan E. , Spiegelman Donna , Colditz Graham A. , Hunter David J. 
Published: June 2022

Abstract
Oxidative stress may be involved in the development of breast cancer. Manganese superoxide dismutase (MnSOD) is one of the primary enzymes that directly scavenge potential harmful oxidizing species. A valine (Val) to alanine (Ala) substitution at amino acid 16, occurring in the mitochondrial targeting sequence of the MnSOD gene, has been associated with an increase in breast cancer risk. We conducted a nested case-control study within the Nurses' Health Study cohort to examine the role of this polymorphism and its interaction with environmental factors with breast cancer risk. MnSOD genotype data are available from 968 incident cases of breast cancer diagnosed after blood collection in 1989 and 1990, but before June 1, 1998 and 1,205 matched controls. Compared with women homozygous for the Val allele, women homozygous for the Ala allele were not at an increased risk of breast cancer (multivariate odds ratio, 0.96; 95% confidence interval, 0.74-1.24). We did not observe any significant interactions between MnSOD genotype with alcohol consumption, postmenopausal hormone use, plasma antioxidant levels, or dietary sources of antioxidants. We did observe evidence that the MnSOD Ala allele may modify the relation of cigarette smoking with breast cancer risk. A nonsignificant increased risk of breast cancer among current smokers was limited to women homozygous for the Ala alleles compared with Val/Val never smokers (multivariate odds ratio, 1.41; 95% confidence interval 0.77-2.60; P for interaction = 0.03). These data suggest that the Ala allele of MnSOD may modify breast cancer risk among current smokers, but is not an independent risk factor for breast cancer.
Early-Onset Colorectal Cancer: A Call for Greater Rigor in Epidemiologic Studies
Authors: Molmenti Christine Louise S. , Jacobs Elizabeth T. , Gupta Samir , Thomson Cynthia A. 
Published: June 2022

Abstract

The rates of early-onset colorectal cancer (EO-CRC) have been rising by 0.5% to 2.4% annually for three decades, accounting for an estimated 12% of all colorectal cancer diagnosed in the United States in 2020. Enhancing the rigor and comprehensiveness of the epidemiology in terms of the exposures and prognostic biomarkers is essential if we are to modify risk factors and underlying mechanisms, ultimately arresting this unduly trend. This commentary serves to describe the disease trend, postulate underlying risk factors and mechanisms driving disease incidence, and proposes a call to action for cancer epidemiologists to promote increased and timely opportunities to intervene on this trend.