Cancer In Korean Women Research Articles

Common Genetic Variants Associated with Breast Cancer in Korean Women and Differential Susceptibility According to Intrinsic Subtype

Recently identified genetic variants from genome-wide association studies (GWAS) on breast cancer have not been validated in Asian populations, except in China. In this study, we sought to confirm the association between known variants and breast cancer in Korean women and further evaluate the associations of individual single nucleotide polymorphisms (SNP) with different intrinsic subtypes of breast cancer. In total, 3,321 invasive breast cancer patients and 3,500 healthy controls were genotyped for five SNPs by using the TaqMan assay. The SNPs genotyped included rs2046210 (6q25.1), rs2981582 (FGFR2), rs889312 (MAP3K1), rs3803662 (TOX3/TNRC9), and rs4973768 (SLC4A7). Tumors were classified into four intrinsic subtypes based on estrogen receptor (ER), progesterone receptor, HER2, and Ki67 expression. All five SNPs were significantly associated with risk of breast cancer in dominant, recessive, and additive models. ORs per risk allele (95% CI) were 1.29 (1.16-1.43), 1.40 (1.18-1.68), 1.22 (1.06-1.41), 1.52 (1.30-1.77), and 1.20 (1.08-1.33) for rs2046210, rs2981582, rs889312, rs3803662, and rs4973768, respectively. A multigene logistic regression risk model was generated with the SNPs. In subtype analysis, all 5 SNPs were associated with the Luminal A subtype. Two SNPs (rs2046210 and rs3803662) were linked to the ER(-)HER2(+) subtype, and only rs2046210 SNP was associated with the triple-negative subtype. The five SNPs from GWAS were significantly associated with breast cancer risk in Korean women. Associations were heterogeneous according to the intrinsic subtype of breast cancer. Our result is an important contribution to the literature about genetic susceptibility for breast cancer in nonwhite populations.

P147 The prevalence of ovarian cancer in Korean women at high risk of hereditary breast-ovarian cancer syndrome

P147 The prevalence of ovarian cancer in Korean women at high risk of hereditary breast-ovarian cancer syndrome

Risk Factors and Control Strategies for the Rapidly Rising Rate of Breast Cancer in Korea

Due to the aging population and tremendous changes in life style over the past decades, cancer has been the leading cause of death in Korea. The incidence rate of breast cancer is the second highest in Korea, and it has shown an annual increase of 6.8% for the past 6 years. The major risk factors of breast cancer in Korean women are as follows: Early menarche, late menopause, late full-term pregnancy (FTP), and low numbers of FTP. Height and body mass index increased the risk of breast cancer in postmenopausal women only. There are ethnic variations in breast cancer due to the differences in genetic susceptibility or exposure to etiologic agent. With the epidemiological evidences on the possibility of further increase of breast cancer in Korea, the Korean Government began implementing the National Cancer Screening Program against breast cancer in 2002. Five-year survival rates for female breast cancer have improved significantly from 78.0% in early 1993-1995 to 90.0% in 2004-2008. This data indicate that improvement of the survival rate may be partially due to the early diagnosis of breast cancer as well as the increased public awareness about the significance of early detection and organized cancer screening program. The current primary prevention programs are geared towards strengthening national prevention campaigns. In accordance with the improvement in 5-year survival rate, the overall cancer mortality has started to decrease. However, breast cancer death rate and incidence rates are still increasing, which need further organized effort by the Korean Government.

High-Density Lipoprotein Cholesterol, Obesity, and Mammographic Density in Korean Women: The Healthy Twin Study

BackgroundHigh-density lipoprotein cholesterol (HDL-C) is reported to be associated with breast cancer risk. To better understand this association, we examined the relationship between HDL-C and mammographic density, a putative intermediate risk factor for breast cancer.MethodsThe study subjects were 711 Korean women from the Healthy Twin study. Lipid parameters were assayed enzymatically in fresh sera, and percent dense area (PDA) and absolute dense area were measured from digital mammograms using a computer-assisted method.ResultsPDA was positively associated with HDL-C in both premenopausal and postmenopausal women in a multivariable-adjusted linear mixed model, but the association did not persist when the model was additionally adjusted for body mass index (BMI). BMI was inversely associated with PDA, and this association did not change after additional adjustment for any lipid parameter. Multivariable-adjusted analysis showed that there were significant additive genetic cross-trait correlations between PDA and both HDL-C (coefficient, 0.175) and triglyceride (coefficient, −0.262). However, those correlations disappeared after additional adjustment for BMI.ConclusionsHDL-C alone is unlikely to increase the risk of breast cancer in Korean women, particularly through changes in breast parenchyma that are apparent in mammographic density. BMI should be included in studies using analytical models where mammographic density is used as an intermediate risk factor for breast cancer.

The Prevalence of Ovarian Cancer in Korean Women at High-Risk for Hereditary Breast-Ovarian Cancer

The Prevalence of Ovarian Cancer in Korean Women at High-Risk for Hereditary Breast-Ovarian Cancer

Plasma antioxidant concentration, not superoxide dismutase polymorphism, is associated with breast cancer risk in Korean women

Disturbances in redox regulation are suggested to be involved in the development of breast cancer. We conducted a hospital-based case-control study to examine the hypothesis that lower plasma antioxidant concentration is related to higher risk of breast cancer and that genetic polymorphism of manganese superoxide dismutase (SOD2) modifies the relationship between breast cancer risk and plasma antioxidant. Genotyping for SOD2 Val16Ala polymorphism was performed by a 5' exonuclease assay, and plasma concentrations of retinol, carotenoids, and tocopherols were determined by high-performance liquid chromatography. Unconditional logistic regression models were used to estimate crude and multivariate odds ratios with a 95% confidence interval. The variant allele frequencies of SOD2 Val16Ala (TC or CC type) were 26% for the control subjects and 23% for the breast cancer patients, and the variant genotype was not a risk factor for breast cancer. Higher plasma retinol concentration was associated with a lower risk, whereas higher plasma β-carotene, α-tocopherol, or γ-tocopherol concentrations were associated with a higher risk of breast cancer. SOD2 CT or CC genotype was associated with lower risk (odds ratio, 0.53; 95% confidence interval, 0.30-0.93; P for interaction = .025) in subjects with low plasma γ-tocopherol concentration. Our findings suggest that the SOD2 Val16Ala variant is not related to the risk of breast cancer in Korean women; however, it may affect the association between plasma γ-tocopherol levels and the risk of breast cancer.

Risk Factors and a Predictive Model for Thyroid Cancer in Korean Women

Thyroid cancer incidence in Korean women has increased radically and is the highest in all cancer types. However, the rate of cancer screening among women is very low. The aim of the study was to determine the risk factors for thyroid cancer and to develop a predictive model based on these risk factors. The study design comprised a literature review and a case-control study. To construct a predictive model, the participants selected were 260 female outpatients diagnosed with malignant neoplasm of thyroid gland who had undergone thyroid removal surgery. A total of 259 people for the control group were selected by adopting a 5-year age-matching method. From the literature review, 6 categories of risk factors were identified. Nine variables, including occupation, live(d) in coastal region, family history of thyroid cancer, history of benign thyroid tumor, menopause status and weight gain, number of full-term deliveries, abortion, exercise intensity, and stress, remained as statistically significant risk factors in the stepwise regression model. Regarding the predictive power of the model, the area under the receiver operating characteristic curve was .79, accuracy was .77, sensitivity was .89, specificity was .65, positive predictive value was .72, and negative predictive value was .85. The predictive power of the model was relatively good, so it can be used to identify individuals at high risk for thyroid cancer. The predictive model can be used in promoting to participate in early cancer-screening tests. Thus, it will be possible to detect thyroid cancer in its earliest stage, diminish mortality, and improve quality of life.

Role of body mass index as a risk and prognostic factor of endometrioid uterine cancer in Korean women

Objective We aimed to evaluate the role of body mass index (BMI) as a risk and prognostic factor of endometrioid uterine cancer in Korean women. Methods The records of 937 patients with endometrioid uterine cancer treated between 2000 and 2006 in Korea were reviewed. To determine the disease risk by BMI, four age-matched controls were recruited from healthy women (1-year age group). Results The obese (BMI ≥ 25 kg/m 2) and overweight (23 kg/m 2≤ BMI < 25 kg/m 2) women had an increased risk for endometrioid uterine cancer (OR = 3.161, 95% CI = 2.655–3.763 and OR = 1.536, 95% CI = 1.260–1.873, respectively) compared to the non-obese (BMI < 23 kg/m 2) women. That is, an increment of 1 kg/m 2 caused an 18% increase in the endometrioid uterine cancer risk (OR = 1.181, 95% CI = 1.155–1.207). However, there was no difference in overall survival according to the BMI-based subgroups (log-rank = 0.366, p = 0.8328). The crude Cox model showed that obesity was not associated with the patients' overall survival when the obese and non-obese women were compared (crude HR = 0.82, 95% CI = 0.40–1.66). Furthermore, there was a significant trend toward a better prognosis at increased increments of BMI ( p for trend < 0.001), but this was not found in the multivariate analysis. Conclusions A high BMI was a significant risk factor for endometrioid uterine cancer in an Asian population. However, it was not associated with overall survival, in spite of the earlier tumor stage of the obese women.

Abstract 4720: Genome-wide copy number variation and breast cancer risk: Preliminary report

Abstract Background: DNA copy number variation (CNV) is a common phenomenon in human genome and some CNVs have been associated with susceptibility or resistance to disease. It has been suggested that gene copy number can be elevated in cancer cells. To evaluate potential role of CNV in breast cancer development, we conducted genome-wide association study of CNV in Seoul Breast Cancer Study. Methods: Cases were diagnosed with breast cancer and underwent curative surgery at two teaching hospitals located in Seoul, Korea, between 2001 and 2007 (n=2,386). Control subjects were selected from multi-center based cohort study in 2007 (n=2,386). The Affymetrix SNP assay 6.0 array, which includes 946,000 probes for the detection of copy number variation, was used. Nexus Copy Number version 4.1 was used for detecting CNVs (significance threshold=10−6; minimum number of probes per segment=4), and statistical analysis. After quality control step (i.e., robust variance sample QC), total 2,315 cases and 2,039 controls were compared for the difference of each CNV. In this study, we selected the CNVs that were different between cases and controls by at least 5% (P adjusted for multiple comparison &amp;lt;0.01). Adjacent CNVs were grouped into CNV regions ranging 10 kb to 300 kb. Results: Between case and controls, thirteen CNV regions including chr115q11.2, chr3q26.1, chr6q16.3, chr17q31.1 were significantly different for copy number. We note that those regions include genes such as UGT2B17 (UDP glucuronosyltransferase 2 family, polypeptide B18), OR4C11 (olfactory receptor, family 4, subfamily C, member 11), LRRC37A2 (leucine rich repeat containing 37, member A2), ARL17P1 (ADP-ribosylation factor-like 17 pseudogene 1), LOC644974, and the others. We are planning validation study for the regions by quantitative PCR to verify the association with breast cancer risk found in this study. Conclusion: Our results suggest that common CNVs may be associated with breast cancer in Korean women. However, further variation study is essential to support our observation and underlying biological mechanisms for the associations needs to be elucidated. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. 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 4720.

PALB2 mutations 1592delT and 229delT are not present in Korean breast cancer patients negative for BRCA1 and BRCA2 mutations

PALB2 is a recently discovered breast cancer susceptibility gene, and mutations in the gene have been demonstrated to confer about twofold higher risk of breast cancer. Truncating mutations in PALB2 gene have been identified in varied populations. However, PALB2's significance to breast cancer has not been investigated in the Korean population. In this study, we evaluated the frequency of PALB2 1592delT and 229delT mutations in 300 Korean breast cancer patients diagnosed with either familial or early-onset breast cancer. All patients were confirmed negative for BRCA1 and BRCA2 mutations. Neither 1592delT nor 229delT mutations was found in any of the study cohort. Our results imply that these mutations are absent or rare in Korean patients who are negative for BRCA1 and BRCA2 mutations. We found no evidence to recommend screening for these mutations in the Korean population. However, PALB2 mutations have been demonstrated infrequent and inhomogeneous across investigated populations. Thus, screening the whole PALB2 gene for novel mutations is required to elucidate its significance in predisposition to breast cancer in Korean women.

Current State and Role of Private Breast Clinic in Korea

increased and as treatments became variable including chemotherapy, it has become inevitably necessary to manage cancer at national level. Accordingly, our country established a ‘10-yr project for defeating cancer’in 1996 and started a national cancer screening program to detect early cancer since 1999. At the beginning, screening was held only for stomach, cervix and breast but from 2004, it has been extended to screen for 5 leading cancers including liver and colon. For the past 10 yr, in Korea, incidence of breast cancer has increased significantly and since 2002, it has become the first leading cancer in Korean women. However, the quality of facilities in Korean medical institutions diagnosing breast cancer primarily could not keep up with the increasing rate of breast cancer. Especially, there were large gaps in standards between mammography instruments. The purpose of taking mammography is to make high contrast/high resolution images with minimum radiation exposal. Obtaining the best breast image requires a mammography machine with proper positioning, compression, Quality Control (QC) program, and appropriate management. The State has already passed the Mammography Quality Standard Act (MQSA) law in 1992 and management has been carried out legally. Hence, Korea announced amendment pertaining to safety standards for mammography instruments in January 2001 as the first step. Moreover, as special law for national health insurance and financial soundness established in January 2002, regulations for special medical equipments installation and operation have been constructed.(1) In April 2002, extensive evaluation for control concerning related equipments brought shocking results. 27.4% of CT (81/296) and 52.7% (69/131) of mammography machine had defects. Based on these results, enforcement was increased and mammography machines have been managed legally as special medical equipment, along with CT and MRI since January 2003. Regarding installation and management of special medical equipment, regular overhaul of Mammography is compulsory. Documentation on inspection of man power, testing for proper quality, and phantom image testing should be checked once a year and the clinical imaging test should be compared with the previous 3 check-up tests every three years as part of thorough examination. It was those periods when surgeons from private practice specializing in breast cancer started to form an organization. It was not until 2000 for breast cancer screening to be generalized throughout the country in private clinics although it actually started in 1992. Most of doctors performing breast cancer check-ups in private clinics were surgeons. Before that time, people preferred general hospitals for breast cancer examination, as they had more confidence in medical team and machines, even though the process was time consuming and expensive. However, people began to change their perception when the private clinics were equipped with same facilities as general hospitals and surgeon became responsible for breast cancer evaluation. Surgeons specially trained for Journal of Breast Cancer

Sleep Quality of Breast Cancer Patients Receiving Chemotherapy in the Outpatients Setting

Background: Breast cancer is the second most common cancer in Korean women. As survival years increase, healthrelated quality of life has become an important issue in breast cancer patients. Sleep problems are common and cause significant disruption in quality of life in breast cancer patients. However, cancer-related sleep disturbance has received little attention. The purpose of this study was to determine the prevalence of poor sleep quality and factors which are associated with poor sleep quality in the breast cancer patients receiving chemotherapy in the outpatients setting. Methods: One hundred and twenty-seven breast cancer patients receiving chemotherapy in a tertiary hospital outpatient were surveyed between February 2009 and July 2009. Among them, 94 (72.8%) patients were finally included in the study. The sleep quality was assessed by the Pittsburg Sleep Quality Index (PSQI). PSQI > 5 indicates clinically significant poor sleep quality. Also the independent factors of sleep quality were assessed using univariable analysis and multiple logistic regression analysis. Results: Seventy-two (76.6%) patients of 94 breast cancer patients undergoing chemotherapy have poor sleep quality. Among of them, 11 (15.3%) patients were actually consulted with doctors. Average PSQI score was 8.8 (± 4.1). Anxiety and employment status were associated with poor sleep quality. Conclusion: A high proportion of breast cancer patients receiving chemotherapy even in the outpatient settings had poor sleep quality. But only small proportion of them consulted doctor. Poor sleep quality during chemotherapy in breast cancer patient was associated with anxiety and employment status. Considering the high prevalence of sleep problem and inadequate management, more adequate attention is needed to manage the sleep problem of breast cancer patients receiving chemotherapy.

The effects of polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and methionine synthase reductase (MTRR) on the risk of cervical intraepithelial neoplasia and cervical cancer in Korean women

The purpose of the study was to investigate the association between cervical cancer risk and single-nucleotide polymorphisms (SNPs) in three one-carbon metabolism genes, methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and methionine synthase reductase (MTRR) in Korean women. Twelve SNPs were identified in MTHFR, MTR, and MTRR in the 927 case-control samples, which included 165 cervical intraepithelial neoplasia 1 (CIN1), 167 cervical intraepithelial neoplasia 2 and 3 (CIN2/3), 155 cervical cancer patients, and 440 normal controls. The frequencies of the genotypes and haplotypes were assessed in the controls, CINs, and cervical cancers. Individual carriers of the variant allele C of MTHFR A1298C (rs1801131) had a 0.64-fold [95% confidence interval (CI): 0.42-0.98] decreased risk for CIN2/3 compared with common homozygotes. However, no significant association was found between most other variants and cervical cancer risk. The results also identified an increased CIN1 risk in carriers with at least one copy of haplotype 3 in the MTHFR gene (odds ratio, 1.88; 95% CI: 1.03-3.42). In conclusion, there was no significant association between most SNPs in MTHFR, MTR, or MTRR and the risk of CIN and cervical cancer in Korean women. In addition, there was no significant association of MTHFR haplotypes with risk of CIN2/3 and cervical cancer.

The effects of obesity and HER‐2 polymorphisms as risk factors for endometrial cancer in Korean women

To evaluate the relationship between single nucleotide polymorphisms (SNPs) in the HER-2 gene, body mass index (BMI) and the risk of endometrial cancer. Case-control study. Medical centres in Korea. DNA samples and medical histories were obtained from 125 endometrial cancer cases and 302 controls. The genotypes evaluated in HER-2 at positions -423, -655, -776, -857, -1170, -1177, -1253 of the coding region and two SNPs located in an intron by SNP-IT assay using SNPstream Ultra-high throughput system. Odd ratio for endometrial cancer associated with HER-2 polymorphisms and BMI. Cases had a significantly higher BMI than controls and the obese subjects had a 2.65-fold increased risk for endometrial cancer. However, HER-2 polymorphism was not associated significantly with the risk of endometrial cancer. Subjects with BMI > or = 25 kg/m2 who carried rs1801200 AA, rs1801200 GA/GG, rs1810132 CT/CC, rs2517951 CT/TT and rs1058808 CG/GG genotype had significantly increased risk of endometrial cancer than subjects with a normal BMI (P for linear trend <0.05). However, the risk in the subjects with the variant allele for HER-2 genotypes did not differ significantly compared to those with homozygous wild-type allele within specific BMI subgroups. Endometrial cancer risk increased significantly in proportion to BMI. However, HER-2 polymorphism did not affect significantly on the risk of endometrial cancer.

Cost‐effective mammography screening in Korea: High incidence of breast cancer in young women

The epidemiological characteristics of breast cancer in Korean women are different from the characteristics reported in Western women. The highest incidence rate occurs in Korean women in their 40s. The purpose of this study was to determine the most cost-effective screening interval and target age range for Korean women from the perspective of the national healthcare system. A stochastic model was used to simulate breast cancer screenings by varying both the screening intervals and the age ranges. The effectiveness of mammography screening was defined as the probability of detecting breast cancer in the preclinical state and the cost was based on the direct cost of mammography screening and the confirmative tests. The age-specific mean sojourn times and the sensitivity of the mammography were applied in the stochastic model. An optimal cost-effectiveness was determined by the incremental cost-effectiveness ratio and lifetime schedule sensitivity. Sensitivity analyses were undertaken to assess parameter uncertainty. The selected cost-effective strategies were: (1) the current biennial mammography screenings for women who are at least 40 years old; (2) biennial screening for women between the ages of 35 and 75 years; and (3) a combination strategy consisting of biennial screening for women aged between 45 and 54 years, and 3-year interval screening for women aged between 40 and 44 years and 55 and 65 years. Further studies should follow to investigate the effectiveness of mammography screening in women younger than 40 years in Asia as well as in Korea.

Preoperative levels of plasma micronutrients are related to endometrial cancer risk

To examine the relation between the plasma concentration of antioxidant micronutrients and endometrial cancer risk in Korean women. Hospital-based case-control study. Seven tertiary medical institutes in Korea. Incidence of 28 endometrial cancer cases were identified and 140 age-matched controls selected for the same period. Preoperative plasma concentrations of beta-carotene, lycopene, zeaxanthin plus lutein, retinol, alpha-tocopherol, and gamma-tocopherol were measured by reverse-phase, gradient high-pressure liquid chromatography. Conditional logistic regression was used to evaluate micronutrient effect after adjustment for body mass index (BMI), menopause, parity, oral contraceptive use, smoking status, and alcohol consumption status. Effect of micronutrients on endometrial cancer risk. The mean concentration of plasma beta-carotene (p=0.001), lycopene (p=0.008), zeaxanthin plus lutein (p=0.031), retinol (p=0.048), and gamma-tocopherol (p=0.046) were significantly lower in endometrial cancer patients than in controls. Plasma levels of beta-carotene (p for trend=0.0007) and lycopene (p for trend=0.007) were inversely associated with endometrial cancer risk across tertiles. Women in the highest tertile of plasma beta-carotene and lycopene had a 0.12-fold (95% confidence intervals (CIs) 0.03-0.48) and 0.15-fold (95% CIs 0.04-0.61) decreased risk of endometrial cancer compared to women in the lowest tertile, respectively. Other micronutrients such as zeaxanthin plus lutein (p for trend=0.142), retinol (p for trend=0.108), alpha-tocopherol (p for trend=0.322), and gamma-tocopherol (p for trend=0.087) showed no association with endometrial cancer risk. Plasma levels of beta-carotene and lycopene are inversely associated with the risk of endometrial cancer in Korean women.

BMI and Breast Cancer in Korean Women: A Meta-Analysis

The number of breast cancer women has increased dramatically in Korea. The cause is perceived to stem from adaptation to a westernized life style which increases body mass index (BMI). However, there are no meta-analysis data available that could help in understanding the relationship between Korean females' BMI and breast cancer occurrence. All the published articles that investigated the relationship of Korean women's BMI with breast cancer prevalence between 1950 and 2007 were included in this study, based on a screen of the comput- erized databases that search for these articles (MEDLINE, RISS4U and KMBase). The commercial software Comprehensive Meta Analysis was used for the analysis. The high BMI score group presented a higher prevalence of breast cancer on both a fixed-effects model [odds ratio (OR) = 1.282; 95% confidence interval (CI) = 1.209, 1.361] and a random-effects model (OR = 1.388; 95% CI = 1.129, 1.706). In addition, a high BMI score on pre- and postmenopausal groups was found to have a significantly higher prevalence of breast cancer on both a fixed-effects model (OR = 1.467; 95% CI = 1.268, 1.698, OR = 1.614; 95% CI = 1.360, 1.917, pre- and postmenopausal, respectively) and a random-effects model (OR = 1.387; 95% CI = 1.134, 1.696, OR = 1.681; 95% CI = 1.149, 2.461, pre- and postmenopausal, respectively). This meta-analysis of Korean women showed that a high BMI was related to a higher inci- dence rate of breast cancer. This study used a subgroup analysis of pre- and postmenopausal groups; the high BMI subset in both the pre- and postmenopausal groups was shown to have a higher incidence rate of breast cancer. [Asian Nursing Research 2009;3(1):31-40].

Clinical Characteristics of Metastatic Tumors to the Ovaries

Approximately 5-30% of the ovarian cancers are metastatic malignancies. The prevalence of metastatic ovarian tumors varies with the incidence rates and spread patterns of primary malignancies. We evaluated the prevalence, pre- and postoperative characteristics of metastatic ovarian cancer in Korean women. We reviewed the records for 821 ovarian malignancies with pathological consultation from 1996-2006 and recorded patient demographical, radiological, histopathological, and survival data. The study included 112 cases of histologically confirmed metastatic ovarian cancer. Metastatic ovarian cancer accounted for 13.6% of all ovarian malignancy, primarily arising from the gastrointestinal tract. The preoperative detection rate with imaging was 75%, and none of the radiological or serological features were useful for differential diagnosis. In multivariate analysis for prognostic variables, the only significant factor was the primary tumor site (p=0.004). Furthermore, extensive resection increased survival for some patients. The differential diagnosis of metastatic ovarian cancer can be problematic, so multiple diagnostic approaches are necessary. The extent of cytoreductive surgery for this type of tumor must be decided on a case-by-case basis.

Effects of bisphenol A on breast cancer and its risk factors

The incidence of breast cancer in Korea has been increasing for the last two decades (1983-2005), and now, breast cancer is ranked the leading cause of cancer in Korean women. Along with other endocrine disrupting chemicals (EDCs), bisphenol A (BPA) has been suspected as a potential risk factor for breast cancer. We studied potential associations between BPA exposure and breast cancer risks in Korean women by performing biomonitoring of BPA among breast cancer patients and controls (N = 167). Blood samples were collected between 1994 and 1997 and kept over 10 years in a freezer under well controlled conditions. The blood BPA levels determined by HPLC/FD, ranged between LOD (0.012 microg/L) and 13.87 microg/L (mean +/- SD, 1.69 +/- 2.57 microg/L; median, 0.043 microg/L). In age-matched subjects (N = 152), there were some associations between BPA levels and risks of breast cancer, such as age at first birth and null parity. However, there were no significant differences in blood BPA levels between the cases and the controls (P = 0.42). Considering interactions between BPA exposure and risks of breast cancer, we suggest further enlarged biomonitoring studies of BPA to provide effective prevention against breast cancer.

Breast cancer risk factors in Korean women: a literature review

To compile a complete list of risk factors from the Korean breast cancer studies to obtain relevant predictor information essential in developing a predictive model for breast cancer. Breast cancer is the most commonly diagnosed female cancer in Korea. However, the breast cancer-screening rate in Korea is relatively low compared with that in other countries. In order to promote early health screening, there is a need to identify those individuals who are most likely to develop breast cancer by using an accurate predictive model. Thirty-four breast cancer studies were selected from MEDLINE and two Korean literature databases. Two researchers summarized the risk factors and their effects in each article using a checklist. Most of the studies were case-control studies conducted after 2000. In 34 articles, a total of 84 risk factors for breast cancer in Korean women were identified; of these, 58 factors were determined as statistically significant factors. The factors identified most often were body mass index, menarche, menopause, family history, pregnancy and delivery, breastfeeding, alcohol use, smoking habits, diet, education and use of oral contraceptives. None of 34 studies looked at stress as a risk factor of which influence on cancer has been reported in other populations. The next steps will be to construct a questionnaire consisting of relevant variables based on these study results and to develop a predictive model. This would be used to encourage those Koreans who are more likely to develop breast cancer to have early check-ups.