Biomedical subjects

Fan Jin

Publications and source records attributed to Fan Jin.

At least 55 records · Page 3Linked to original sources

PubMed2004

Use of complementary and alternative medicine by chinese women with breast cancer.

The use of complementary and alternative medicine (CAM) has been rapidly increasing among cancer patients. The aim of this study is to evaluate the prevalence and patterns of CAM use, particularly patients' intentions and their perceived effectiveness of using Chinese herbal medicine (CHM), as well as the relations between the herbal medicine use and demographic and clinical factors among Chinese women with breast cancer. We analyzed the data from a population-based sample of 1065 breast cancer women in urban Shanghai. Patients' average age at diagnosis was 48.1 years and the median time from the initial diagnosis to the follow-up survey was 4.3 years. Overall, 98% of patients had used at least one form of CAM therapy after diagnosis of breast cancer. The most popular CAM modality was traditional Chinese medicine (86.7%), followed by the use of supplements (84.8%), physical exercises (65.5%), and support group attendance (16.6%). CHM was used by 86.4% of patients, while acupuncture was used only by 4.9% of patients. Treating cancer (81.5%) was the most common intentions of using CHM. Other cited intentions included enhancing the immune system (12%), preventing metastasis of cancer or managing other discomforts (7.9%), and lessening menopausal symptoms (4.7%). The majority of patients reported that they had benefited from the use of CHM. Patients who were younger, married, had higher education or income, received chemotherapy or radiotherapy, or had recurrence/metastasis of cancer tended to use CHM more frequently than other patients. The relations between patient characteristics and use of CHMs varied with users' intentions. Given the high prevalence of CAM use among breast cancer patients, research is urgently needed to systematically evaluate the efficacy and safety of CAM use, particularly use of herbal medicines.

Adult↗

PubMed2004

The long-term impact of medical and socio-demographic factors on the quality of life of breast cancer survivors among Chinese women.

Quality of life (QOL) has become an integral part of the modern assessment of cancer treatment in Western society. However, little is known about the QOL of Chinese breast cancer survivors. To evaluate the long-term impact of medical and socio-demographic factors on survivors' QOL, we conducted a population-based study of 1065 breast cancer survivors in Shanghai, China. The mean age at diagnosis was 48.1 years and the median survival time was 4.3 years for the study participants. The Generic Quality of Life Inventory was used to assess survivors' QOL. Multiple linear regression models were employed to analyze the associations of QOL outcomes with socio-demographic and medical factors. The results revealed that recurrence status, time since diagnosis, marital status, income and education all had an independent, significant association with overall QOL and differential domains of QOL. Age at diagnosis exhibited a dual effect on QOL, positively associated with material well-being and negatively associated with physical well-being. Stage of disease was only associated with social well-being, while the type of surgery was related to material well-being alone. No associations between QOL and chemotherapy or radiotherapy were found. Further, analyses by survival intervals suggested a domain-specific order of recovery of QOL after cancer treatment. These results fill gaps in the limited literature, and provide valuable information for physicians to target the specific needs of Chinese women with breast cancer, choose appropriate interventions at the optimal time, and develop strategies accordingly in terms of improvement of patient's QOL.

Adult↗

PubMed2004

Correlation of blood sex steroid hormones with body size, body fat distribution, and other known risk factors for breast cancer in post-menopausal Chinese women.

OBJECTIVE: Estrogen plays a central role in breast cancer. It has been suggested that many known breast cancer risk factors may exert their effect via levels of endogenous sex hormones. The objective of this analysis is to evaluate the association between measures of body size, dietary macronutrient intake, and reproductive factors with levels of endogenous sex hormones among women living in Shanghai, China. METHODS: Included in this study were 420 post-menopausal healthy women randomly selected from the general population as controls who participated in the Shanghai Breast Cancer Study, a population-based case-control study conducted in Shanghai, China between 1996 and 1998. Comprehensive dietary and reproductive information was collected using a structured questionnaire during an in-person interview and anthropometrics were measured by trained interviewers according to a standard protocol. Hormone levels were log-transformed and Pearson correlation coefficients were calculated to determine the correlation between hormone levels and selected breast cancer risk factors. RESULTS: Measures of body size were strongly correlated with hormone levels. In particular, weight, waist circumference, and hip circumference were significantly positively correlated (p < 0.05) with levels of testosterone, estradiol, estrone, and significantly negatively correlated with sex hormone binding globulin. Macronutrient intake and reproductive factors were not correlated with endogenous sex hormone levels. CONCLUSIONS: These data suggest that breast cancer risk associated with measures of body size may be mediated, at least partially, by levels of endogenous sex hormones.

Adult↗

PubMed2004

Physical activity, body size, and estrogen metabolism in women.

OBJECTIVES: Physical activity has demonstrable effects on estrogen levels in pre- and postmenopausal women. Increased oxidation of estrone to 2-hydroxyestrone (2HE) relative to 16alpha-hydroxyestrone (16HE) has been hypothesized to reduce breast cancer risk, but little is known about the effect of physical activity and body size in relation to the ratio of 2HE and 16HE in women. We examined these relationships in cross-sectional analyses of 157 North American and Chinese women. METHODS: Physical activity was assessed using validated questionnaires. Adiposity was assessed as body mass index (BMI, kg/m2) and by anthropometric methods (% body fat). Estrone metabolites, 2HE and 16HE, were determined from urine via ELISA. RESULTS: Regression analyses on the 2HE/16HE ratio revealed an interaction between leisure-time physical activities and adiposity in both North American and Chinese women (p < or = 0.05). Women reporting low levels of leisure-time physical activity who had higher BMI levels had 2HE/16HE ratios that were lower than their lean counterparts. In contrast, women with higher BMI levels that were physically active maintained higher 2HE/16HE ratios. CONCLUSION: These findings suggest that physical activity participation has the potential to modify the adverse effect of increased adiposity on estrogen metabolism in North American and Chinese women.

Adipose Tissue↗

PubMed2004

MTHFR polymorphisms, dietary folate intake, and breast cancer risk: results from the Shanghai Breast Cancer Study.

Folate plays an important role in DNA methylation, synthesis, and repair; intake has been associated with breast cancer. The folate-metabolizing enzyme, methylenetetrahydrofolate reductase (MTHFR) is polymorphic at nucleotides 677 (C-->T) and 1298 (A-->C), resulting in allozymes with decreased activity. We evaluated these two common polymorphisms and their effects on the folate intake and breast cancer risk association in a population-based case-control study of 1144 breast cancer cases and 1236 controls using a PCR-RFLP-based assay. All subjects completed in-person interviews, which included a food frequency questionnaire. Unconditional logistic regression models were used to calculate odds ratios and their 95% confidence intervals, after adjusting for potential confounding factors. Cases and controls were similar in the distribution of MTHFR polymorphisms at codons 677 (41.4% cases and 41.8% controls carried the T allele) and 1298 (17.6% cases and 17.5% controls carried the C allele). An inverse association of breast cancer risk with folate intake was observed in all genotype groups, particularly among subjects with the 677TT genotype. Compared with those with the 677CC genotype and high folate, the adjusted odds ratios (95% confidence intervals) associated with low folate intake were 1.94 (1.15-3.26), 2.17 (1.34-3.51), and 2.51 (1.37-4.60) for subjects who had CC, CT, and TT genotypes (p for interaction, 0.05). No modifying effect of A1298C genotypes on the association of folate intake with breast cancer risk was observed. Results of this study suggest that the MTHFR C677T polymorphisms may modify the association between dietary folate intake and breast cancer risk.

Adult↗

PubMed2004

Genetic polymorphisms in GSTM1, GSTP1, and GSTT1 and the risk for breast cancer: results from the Shanghai Breast Cancer Study and meta-analysis.

PURPOSE: We studied the relation of breast cancer to common deletion mutations in GSTM1 and GSTT1 and the functional Ile(105)Val polymorphism in GSTP1 in a large, population-based case-control study conducted in China and performed a meta-analysis to summarize the literature. EXPERIMENTAL DESIGN: In the case-control study, a total of 1144 breast cancer cases and 1221 community controls were genotyped for GSTM1, GSTP1, and GSTT1 using PCR-based methods. Associations of genotypes and breast cancer were evaluated in logistic regression models. Meta-analysis odds ratios (ORs) were estimated using a fixed effects model. RESULTS: In the case-control study, associations were null for GSTM1 [age-adjusted OR 0.97, 95% confidence interval (CI): 0.82-1.14] and GSTT1 (OR 0.97, 95% CI: 0.83-1.15). A significant increase in risk was observed among homozygotes for the variant Ile(105)Val polymorphism (OR 1.92, 95% CI: 1.21-3.04). No combined effects of GSTM1, GSTP1, and GSTT1 genotypes or interactions with potential effect modifiers were detected. All results were similar in pre- and postmenopausal women and for early versus advanced stage breast cancer. The meta-analysis, based predominantly on Caucasian women, supported null results for the homozygous deletion variant in GSTM1 (summary OR 1.05; combining 19 studies) and GSTT1 (summary OR 1.11; 15 studies). Meta-analysis results for the homozygous GSTP1 variant indicated no overall association (summary OR 1.04; 10 studies), although results varied significantly across studies (P = 0.009). CONCLUSIONS: This large case-control study provides strong support for earlier studies showing no overall association of the GSTM1 and GSTT1 deletion polymorphisms with breast cancer risk. The GSTP1 variant may be relevant to breast cancer risk in Asian populations.

Acyltransferases↗

PubMed2004

Identification of embryonic chromosomal abnormality using FISH-based preimplantation genetic diagnosis.

OBJECTIVE: Embryonic chromosomal abnormality is one of the main reasons for in vitro fertilization (IVF) failure. This study aimed at evaluating the value of Fluorescence in-situ Hybridization (FISH)-based Preimplantation Genetic Diagnosis (PGD) in screening for embryonic chromosomal abnormality to increase the successful rate of IVF. METHOD: Ten couples, four with high risk of chromosomal abnormality and six infertile couples, underwent FISH-based PGD during IVF procedure. At day 3, one or two blastomeres were aspirated from each embryo. Biopsied blastomeres were examined using FISH analysis to screen out embryos with chromosomal abnormalities. At day 4, embryos without detectable chromosomal abnormality were transferred to the mother bodies as in regular IVF. RESULTS: Among 54 embryos screened using FISH-based PGD, 30 embryos were detected to have chromosomal abnormalities. The 24 healthy embryos were implanted, resulting in four clinical pregnancies, two of which led to successful normal birth of two healthy babies; one to ongoing pregnancy during the writing of this article; and one to ectopic pregnancy. CONCLUSION: FISH-based PGD is an effective method for detecting embryonic chromosomal abnormality, which is one of the common causes of spontaneous miscarriages and chromosomally unbalanced offsprings.

Adult↗

PubMed2004

[Trends analysis of common urologic neoplasm incidence of elderly people in Shanghai, 1973-1999].

BACKGROUND & OBJECTIVE: Few studies on trend analysis in cancer incidence of the elderly people in China. The purpose of this study was to analyze time trends in urologic cancer incidence of the elderly people during the period 1973-1999 in Shanghai. METHODS: The registered cancer cases were coded according to the 3-digit rubrics of the ninth revision of the International Classification of Diseases (ICD-9). Population estimates were based on periodic censuses, with age- and sex-specific annual estimates derived by linear inter- and extrapolation for the remaining years. The age-standardized rates adjusted to the world population were calculated for nine 3-year periods. Annual percent changes in incidence were estimated by means of a linear regression of the respective rates on the mid-point of calendar years, weighted by the number of cases. RESULTS: During the 27-year period, cancers of prostate, bladder, and kidney have risen substantially among elderly male residents in Shanghai. The annual percent changes were 6.60%, 1.15%, and 5.30%, respectively. Among the elderly women, the rate of kidney cancer increased rapidly, with the annual percent change of 4.87%. The 75 years and older age group in women had substantial increases in incidence rates of bladder cancer. CONCLUSION: From 1973 to 1999, the incidence rates of the commonly urologic cancers increased substantially among the elderly residents in Shanghai, except for female bladder cancer.

Adult↗

PubMed2004

Oral contraceptive use and breast cancer risk: modification by NAD(P)H:quinone oxoreductase (NQO1) genetic polymorphisms.

Despite intensive study, the relationship between oral contraception (OC) and breast cancer remains unclear. OCs contain a potent synthetic estrogen (ethinyl estradiol) but lower endogenous estradiol levels, and ethinyl estradiol is a weak progenitor of semiquinones, catechol estrogens capable of damaging DNA. NAD(P)H:quinone oxoreductase (NQO1) stabilizes semiquinones, thus potentially preventing genetic damage from catechol estrogens, and the NQO1 C609T polymorphism seems functionally relevant. Using data from the Shanghai Breast Cancer Study, a population-based case-control study, we investigated the relationships between OC use (20% ever using), breast cancer, and NQO1 (C/C 31% and C/T + T/T 69%) among 1,039 cases and 1,121 controls. Breast cancer was not significantly associated with NQO1 genotype. There was a significant protective association between OC after age 30 years and premenopausal breast cancer [odds ratio (OR) 0.51, 95% confidence interval (95% CI) 0.29-0.89] primarily with the NQO1 T allele (C/C OR 0.76, 95% CI 0.31-1.82; C/T + T/T OR 0.38, 95% CI 0.18-0.80; P for interaction = 0.19). The association between premenopausal breast cancer and OCs significantly differed with NQO1 genotype when using OCs for >18 months (C/C OR 2.34, 95% CI 0.92-5.99; C/T + T/T OR 0.69, 95% CI 0.38-1.25; P for interaction = 0.02). Among women with the C/C genotype, postmenopausal breast cancer was significantly associated with ever-using OCs (C/C OR 2.01, 95% CI 1.08-3.74; C/T + T/T OR 0.72, 95% CI 0.49-1.05; P for interaction < 0.01). This crossover was stronger with OC use prior to age 30 years (C/C OR 3.00, 95% CI 1.43-6.25; C/T or T/T OR 0.49, 95% CI 0.29-0.81; P for interaction < 0.01). Our results require confirmation but suggest that the OC and breast cancer association depends on the ability to invoke protection from catechol estrogens.

Adult↗

PubMed2004

[Preimplantation genetic diagnosis of chromosome abnormality by fluorescence in-situ hybridization].

OBJECTIVE: To perform preimplantation genetic diagnosis (PGD) of chromosome abnormality using fluorescence in-situ hybridization (FISH). METHODS: Ten couples were presented for preimplantation genetic diagnosis. They had a total of 10 oocyte pick-up cycles. The collected oocytes were inseminated by intracytoplasmic sperm injection. PGD was carried out using cleavage-stage (day 3) embryo biopsy, fluorescence in-situ hybridization, and day 4 embryo transfer. RESULTS: Ten oocyte pick-up cycles yielded 158 oocytes. Among the 94 embryos obtained, 54 embryos were biopsied and FISH analyses were performed for 51 blastomeres. Twenty-four embryos were transferred on the fourth day. There were 4 clinical pregnancies: 3 infants have been born, and 1 couple had ectopic pregnancy. CONCLUSION: PGD is a valuable method to prevent the high risk of spontaneous miscarriages and conceiving chromosomally unbalanced offspring.

Abortion, Spontaneous↗

PubMed2004

[Detecting microdeletions of the Y chromosome in patients with high follicle-stimulating hormone azoospermia].

OBJECTIVE: To explore the relationship between the patients' high follicle-stimulating hormone (FSH) azoospermia and microdeletions in Y chromosome. METHODS: Eleven sequence tagged sites (STSs) in Yq were detected by PCR in 16 male patients' high FSH azoospermia. RESULTS: Microdeletions were observed in 6 of 16 male patients and the deletion rate was 37.5%(6/16). Five types of microdeletions were detected: AZFc(SY152), AZFc (SY152+SY254)+AZFd (SY153), AZFc (SY152+SY254+SY255)+AZFd (SY153), AZFc (SY152+SY158+SY255)+AZFd (SY153),and AZFb (SY130)+AZFc (SY158+SY254+SY255)+AZFd (SY153) respectively. CONCLUSION: Microdeletion of Y chromosome was one of the important reasons of the patients' high FSH azoospermia. Before the application of assisted-reproductive technology (ART) to the patients, it is necessary to detect the microdeletions, especially AZFc and AZFd.

Azoospermia↗

PubMed2004

[Expressions of peripheral lymph node addressin and GlcNAc-6-sulfotransferase in endometrium and their impacts on implantation].

OBJECTIVE: To investigate the expressions of peripheral lymph node addressin(PNAd) and GlcNAc-6-sulfotransferase (GlcNAc6ST) in endometrium and their impacts on implantation. METHODS: PNAd expression in endometrium was examined by immunohistochemistry and Western Blot from 75 women (12 from healthy women, in proliferative phase; 63 from sterile women, of whom, 27 were in early-secretory and 36 in mid-secretory phase). GlcNAc6ST mRNA was examined by real-time PCR in 41 sterile women. The 63 sterile women had underwent IVF-ET and were consequently divided into clinical pregnant (29 cases) and nonpregnant (34 cases) groups. RESULTS: (1) PNAd localized to the membrane and cytoplasm of luminal and glandular epithelia. Staining was patchy and much less intense during the proliferative phase than during the secretory phase. In Western Blot of PNAd, four bands appeared, which were Sgp200, CD34, MAdCAM-1, GlyCAM-1 respectively, and each was positively correlated with the others significantly. The former three molecular levels were significantly higher during the secretory phase as compared with the proliferative phase. Message RNA of GlcNAc6ST was positive in all cases and showed no correlation with any component of PNAd. (2)The expressions of CD34 and GlyCAM-1, but not Sgp200 and MAdCAM-1, were significantly higher in pregnant women than in nonpregnant ones. However, the GlcNAc6ST mRNA level did not differ between groups. (3) No significant difference was found in female age, methods of fertilization, thickness of endometrium on day hCG, cumulative embryo score(CES) and mean score of transferred embryo(MSTE) between the groups. CONCLUSION: PNAd expression in the human endometrium fluctuates with the menstrual cycle. Elevated CD34 and GlyCAM-1 during the secretory phase might be stimulative factors for embryo implantation. Defect in PNAd expression may account for a portion of unexplained infertility.

Adult↗

PubMed2003

Reproducibility and validity of the Shanghai Women's Health Study physical activity questionnaire.

In this investigation, the authors evaluated the reproducibility and validity of the Shanghai Women's Health Study (SWHS) physical activity questionnaire (PAQ), which was administered in a cohort study of approximately 75,000 Chinese women aged 40-70 years. Reproducibility (2-year test-retest) was evaluated using kappa statistics and intraclass correlation coefficients (ICCs). Validity was evaluated by comparing Spearman correlations (r) for the SWHS PAQ with two criterion measures administered over a period of 12 months: four 7-day physical activity logs and up to 28 7-day PAQs. Women were recruited from the SWHS cohort (n = 200). Results indicated that the reproducibility of adolescent and adult exercise participation (kappa = 0.85 and kappa = 0.64, respectively) and years of adolescent exercise and adult exercise energy expenditure (ICC = 0.83 and ICC = 0.70, respectively) was reasonable. Reproducibility values for adult lifestyle activities were lower (ICC = 0.14-0.54). Significant correlations between the PAQ and criterion measures of adult exercise were observed for the first PAQ administration (physical activity log, r = 0.50; 7-day PAQ, r = 0.62) and the second PAQ administration (physical activity log, r = 0.74; 7-day PAQ, r = 0.80). Significant correlations between PAQ lifestyle activities and the 7-day PAQ were also noted (r = 0.33-0.88). These data indicate that the SWHS PAQ is a reproducible and valid measure of exercise behaviors and that it demonstrates utility in stratifying women by levels of important lifestyle activities (e.g., housework, walking, cycling).

Adolescent↗

PubMed2003

Association of breast cancer risk with a GT dinucleotide repeat polymorphism upstream of the estrogen receptor-alpha gene.

Recent studies suggest that genetic polymorphisms of the estrogen receptor-alpha (ER-alpha) gene may be associated with breast cancer risk. To evaluate the role of this gene in the risk of breast cancer, we genotyped a newly identified GT dinucleotide repeat [(GT)(n)] polymorphism located in the promoter region (6.6 kb upstream of the transcription start site) in 947 breast cancer cases and 993 age frequency-matched community controls from a population-based case-control study conducted among Chinese in urban Shanghai. Sixteen alleles were identified, the most common one having 16 GT repeats [(GT)(16)]. Compared with subjects homozygous for this allele, subjects carrying the (GT)(17) or (GT)(18) allele had a decreased risk of breast cancer. The odds ratios (ORs) were 0.81 [95% confidence interval (CI), 0.62-1.06] and 0.58 (95% CI, 0.36-0.94), respectively, for one and two copies of the (GT)(17) or (GT)(18) allele. The inverse association with carrying either of these alleles was stronger among women with >30 years of menstrual cycles (OR 0.66; 95% CI 0.51-0.85) than those with a shorter duration of menstrual cycles (OR 0.97; 95% CI 0.73-1.27), and the test for an interaction was statistically significant (P = 0.04). Among breast cancer patients, the presence of either the (GT)(17) or (GT)(18) allele was associated with a reduced expression of progesterone receptor. Results of this study indicate that the GT dinucleotide repeat polymorphism in ER-alpha gene promoter region may be a new biomarker for genetic susceptibility to breast cancer.

Adult↗

PubMed2003

Urinary isothiocyanate levels, brassica, and human breast cancer.

Brassica vegetable consumption (e.g., Chinese cabbage) provides isothiocyanates (ITC) and other glucosinolate derivatives capable of inducing Phase II enzymes [e.g., glutathione S-transferases (GSTM1, GSTT1, and GSTP1) and NADPH quinine oxidoreductase] and apoptosis, altering steroid hormone metabolism, regulating estrogen receptor response, and stabilizing cellular proliferation. Asian populations consuming large amounts of Brassica have a lower breast cancer incidence compared with Western populations; however, the association between Brassica consumption and breast cancer risk is uncertain. It is difficult to estimate glucosinolate exposure and degradation in humans, possibly limiting epidemiological investigations of Brassica and cancer associations. We conducted a case control investigation of breast cancer in Shanghai, China, using urinary ITC levels as a biological measure of glucosinolate intake and degradation in populations with habitual Brassica intake. A representative subgroup of 337 cases providing presurgery, fasting, and first-morning urine specimens was one-to-one matched (age, menopausal status, date of urine collection, and day of laboratory assay) to population controls. Urinary ITC levels were inversely associated with breast cancer [odds ratio (OR) (Quartile 1) = 1 (ref); OR(Q2) = 0.9, 95% confidence interval (0.6, 1.4); OR(Q3) = 0.7, (0.5, 1.1); OR(Q4) = 0.5, (0.3, 0.8), adjusted for age, menopausal status, soy protein, fibroadenoma history, family breast cancer, physical activity, waist-to-hip ratio, body mass index, age at menarche, and parity in conditional logistic model]. This protective association persisted within post and premenopausal women. In contrast, total Brassica intake estimated from a food frequency questionnaire was not associated with breast cancer. Trends in the association between urinary ITC and breast cancer were more consistent with homozygous deletion of GSTM1 or GSTT1, the AAgenotype of GSTP1 (A313G), or with the C allele of NADPH quinine oxidoreductase (C609T), although interactions were not statistically significant. In conclusion, greater Brassica vegetable consumption, as measured by the urinary ITC biomarker, was associated with significantly reduced breast cancer risk among Chinese women.

Adult↗

PubMed2003

Intake of fruits, vegetables and selected micronutrients in relation to the risk of breast cancer.

High fruit and vegetable intake has been linked with a reduced risk of breast cancer, but evidence is not consistent. We investigated the associations of breast cancer risk with vegetables, fruits and related micronutrient intake in a population-based case-control study among Chinese women in Shanghai, where dietary patterns differ substantially from other study populations. Included in the study were 1,459 incident breast cancer cases and 1,556 frequency-matched controls. Usual dietary habits were assessed by in-person interviews. Logistic regression was used to compute adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to measure strength of the associations. There was no association between breast cancer risk and total vegetable intake. The risk of breast cancer declined, however, with increasing intake of dark yellow-orange vegetables (trend test, p = 0.02), Chinese white turnips (trend test, p </= 0.001), and certain dark green vegetables (trend test, p </= 0.001) with adjusted OR in the highest quintile being 0.79 (95% CI = 0.60-0.98), 0.67 (95% CI = 0.53-0.85) and 0.65 (95% CI = 0.51-0.83) respectively. Intake of fruits, except watermelons and apples, was inversely associated with breast cancer risk (p-values for trend tests </=0.05). Our study suggests that high intake of certain vegetables and fruits may be associated with a reduced risk of breast cancer.

Adult↗

PubMed2003

Plasma sex steroid hormones and breast cancer risk in Chinese women.

Estrogens regulate the growth and differentiation of mammary cells and play an important role in the development of breast cancer. High circulating levels of estrogens are associated with increased risk of breast cancer in Caucasian women. Because Asian women have low estrogens in the circulation compared with their Caucasian counterparts, the effect of estrogens on breast cancer risk in populations with low circulating estrogens remains to be elucidated. We conducted a population-based case-control study in China to evaluate the association of sex steroid hormones with breast cancer risk in Chinese women. Our study included 300 incident cases with primary breast cancer and 300 age- and menopausal status-matched healthy controls randomly selected from the general population in Shanghai. Fasting blood samples were collected from cases prior to any treatment and from their matched controls. Commercial immunoassays were used to measure plasma concentrations of estradiol, estrone, estrone sulfate, testosterone, progesterone, dehydroepiandrosteindian sulfate (DHEA-S) and steroid hormone-binding globulin (SHBG). Conditional logistic regression analysis was performed to examine the association between steroid hormones and breast cancer risk. The results showed that breast cancer risk was elevated with increasing levels of estrone and testosterone (p for trend < 0.05) but not with DHEA-S, estradiol, estrone sulfate, progesterone or SHBG. The estimated relative risks between upper and lower tertiles were 2.07 (95% confidence interval [CI] 0.97-4.41) for estrone in postmenopausal women, 2.01 (95% CI 0.96-4.21) for testosterone in premenopausal women, and 2.40 (95% CI 1.11-5.21) for testosterone in postmenopausal women, after adjusting for age at first live birth, waist-to-hip ratio, total calorie intake, a history of fibroadenoma, a family history of breast cancer and SHBG. These results, in general, are consistent with the findings in Caucasian women and indicate that high sex steroid hormones in the circulation, both androgen and estrogen, are associated with increased risk of breast cancer even in populations with relatively low sex hormones.

Adult↗

PubMed2003

Urinary estrogen metabolites and breast cancer: differential pattern of risk found with pre- versus post-treatment collection.

INTRODUCTION: The products of estrogen metabolism may affect breast carcinogenesis. The 16alpha-hydroxyestrone (16-OHE) metabolite has a higher affinity for the estrogen receptor (ER) than the 2-hydroxyestrone (2-OHE) metabolite, while conjugated 2-OHE metabolite may inhibit angiogenesis. We investigated the association between the relative concentrations of these metabolites in urine (2-OHE/16-OHE) and breast cancer in a case-control study of Chinese women living in Shanghai. METHODS: Incident breast cancer cases between 25 and 65 years of age (n=110) were identified from hospital or population tumor registries in Shanghai, China. Controls (n=110) were randomly selected from a complete registry of the Shanghai population, and individually matched to cases by menopausal status, age, and pre-treatment or post-treatment urine collection time. Urine samples were collected prior to any breast cancer treatment or surgery among 78 case-control pairs, while urine was collected after surgery, and perhaps other treatments, among 32 case-control pairs. A commercial enzyme-immunoassay kit was used to measure urinary estrogen metabolite concentrations. Conditional logistic regression was used to calculate odds ratios summarizing the 2-OHE/16-OHE and breast cancer association within subjects providing either pre-treatment or post-treatment urine samples. RESULTS: Subjects with a higher urinary 2-OHE/16-OHE ratio were less likely to be diagnosed with breast cancer, but only when urine samples were collected prior to breast cancer treatment (OR(Tertile3(T3)versusTertile1(T1))=0.5, 95% CI (0.2, 1.1)). In contrast, a higher 2-OHE/16-OHE ratio was significantly associated with breast cancer among subjects providing urine specimens after treatment initiation (OR(T3versusT1)=8.7, 95% CI (1.6, 47.1)). This observed cross-over modification occurred within both pre-menopausal and post-menopausal women, and independent of body mass index or recent dietary intake. CONCLUSION: Cross-study differences in urine collection protocols may explain observed inconsistencies in the 2-OHE/16-OHE and breast cancer association. Our case-control analysis using pre-treatment urine samples suggested that a lower 2-OHE/16-OHE ratio was associated with an increased risk of pre-menopausal and post-menopausal breast cancer diagnosis among Chinese women.

Adult↗