Breast cancer risk factors in Korean women: a literature review

Aim:  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.
Background:  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.
Methods:  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.
Findings:  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.
Conclusion:  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.     

Implications of systematic review for breast cancer prediction

Highly accurate and predictive models are essential components to promote early breast cancer screening in primary care or home care settings. This study was conducted to demonstrate how the relevant variable selection process influenced the predictive performance of the model to identify individuals at high risk for breast cancer. As such, as a strategy to increase the predictive performance of the models, a systematic review of previously published articles was conducted to select important risk factors for breast cancer. Through the systematic literature review and the application of variable selection methods, 13 final risk factors were identified. Logistic regression and naive Bayes predictive modeling techniques were used. Both models had higher predictive performances than previously developed models. It is believed that the systematic literature review process contributed to the identification of relevant variables and increased the predictive performance of the models. This study also implies that the naive Bayes was equivalent to and could be preferred over logistic regression.     

Primary breast cancer: risk factors, diagnosis and management

This article focuses on the risk factors, diagnosis and management of primary breast cancer. It describes the treatments that may be offered to patients including surgery, chemotherapy, radiotherapy, hormone therapy and targeted therapy. The role of the nurse in caring for patients with breast cancer is also discussed.     

Epidemiological risk factors for breast cancer--a review

The rising global incidence, morbidity and mortality from breast cancer has led to intensified efforts in the search for etiological factors of the disease. While international variations in the incidence of the disease may implicate a role for environmental factors, available evidence indicates that lifetime estrogen exposure may be a critical factor in breast carcinogenesis. While increasing age and the female sex are well-recognized risk factors, reproductive characteristics such as age at menarche and menopause, menstrual irregularity, age at first and last childbirth, parity and breastfeeding have also been linked to breast carcinogenesis. Early menarche and late menopause are associated with increased lifetime exposure to estrogens. In addition, a long period from Tanner stage breast-2 to onset of ovulatory cycles and a long period of luteal inadequacy and anovulatory cycles characteristic of the perimenopausal years creates long estrogen windows favorable for tumor induction. The intense differentiation of the terminal duct lobular unit associated with each full term pregnancy and release of various hormones, autocrine and paracrine growth factors during lactation may explain the protective effects of early age at first full term pregnancy, parity and lactation of breast cancer risk. A protective role for xenoestrogens has been postulated and evidence is emerging in support of an increased breast cancer risk with abortion and prolonged use of postmenopausal hormone replacement therapy. Appreciating relevant risk factors for breast cancer in the population is central to any preventive and control program aimed at reducing the burden of the disease through the design and implementation of culturally sensitive interventions.     

Assessing breast cancer risk

PREVIEW

Genetic syndromes that convey a significant risk of breast cancer are responsible for a small but significant percentage of these cancers. However, the vast majority of breast cancers occur in women with no family history of the disease. Nongenetic risk factors include age, previous breast disease, breast tissue density, radiation exposure, and lifestyle factors, such as weight, exercise, and alcohol consumption. In this article, the authors outline genetic and other risk factors for breast cancer, explore risk-reduction strategies, and encourage primary care physicians to assess breast cancer risk in all their patients.     

Risk factors for breast cancer

Despite the numerous risk factors for the development of breast cancer that have been investigated, only a few demonstrate a clear association with breast cancer development. Female gender and increasing age are the most important factors, followed by factors involving a woman's menstrual, reproductive, and family history. The risks related to menstruation and reproduction are probably related to the duration of estrogenic breast stimulation. The relationship of family history and breast cancer risk is unclear, but there may be a true genetic basis. The previous occurrence of breast cancer (invasive or in situ), the presence of proliferative pathological changes, especially with atypia, and the presence of other malignancies (e.g., primary ovarian and endometrial cancer) are histological risk factors for the development of new or recurrent breast cancer. Radiation exposure, the use of exogenous estrogens (both estrogen replacement therapy and oral contraceptives), diet (especially fat consumption), and alcohol intake may all play a role in cancer risk. Certain medications as well as patient demographics may also have a weak association. Cigarette smoking, caffeine consumption, and stress presently have little support for an association with breast cancer risk. It should be noted that in only one in four patients can breast cancer be accounted for by the known risk factors. This demonstrates that although presently known risk factors may help in screening for the early detection of breast carcinoma, in its possible prevention by modulation of influenceable factors, and in advising patients about their risks, these factors are merely strong associations with breast cancer incidence and not actual causations. The mechanisms of the development of breast cancer are as yet unknown.     

Knowledge, practice, and risk of breast cancer among rural women in Korea

Abstract Breast cancer is the third leading cause of death among Korean women after stomach and cervical cancer. Furthermore, the incidence of breast cancer is increasing in contrast to decreasing trends of those two cancers described above. According to the Korean Ministry of Health and Welfare, in 1998, 6.1% of all cancers and 14.1% of cancers in women were breast cancers. Early detection of breast cancer can be achieved by performing periodic breast self-examinations (BSE), clinical breast examinations, and/or mammography. Women should perform early detection procedures such as BSE or mammography on a regular basis to detect breast cancer earlier. For the cost effectiveness of the program, the identification of high-risk groups should be conducted, and the provision of community programs for the early detection of breast cancers should be focused on high-risk groups. The present study was designed to classify the high-risk groups of breast cancer among rural women in Korea, to provide early detection of breast cancer programs. Breast cancer risk of each participant, aged 35–65 years and who reside in the Korean rural community including Kyungki-Do and Chungchongbuk-Do, was assessed utilizing the breast cancer risk appraisal instruments. The tool estimates the six risk factors including age, family history, personal breast disease history, breast-feeding experience, number of children, and frequency of fat intakes. Breast cancer-related knowledge and practices were also assessed. The study results identified a 1.5% high-risk group, 3.8% moderate-risk group, and 24.0% borderline-risk group. Approximately 30% of the respondents were above the borderline-risk groups, which indicate the need for systematic approach for breast cancer prevention and early detection in the community.     

Lactation and risk of endometrial cancer in Japan: a case-control study

The incidence of endometrial cancer is rapidly increasing in Japan. Although the risk factors in European populations have been well described, there are few epidemiologic studies regarding risk factors for endometrial cancer in Japanese women. This hospital-based case-control study among Japanese women was carried out from 1998 to 2000. The cases were selected from women with endometrial cancer (n =155), and the controls selected from women attending the university gynecological outpatient clinic for cervical cancer screening (n = 96). Subjects were interviewed to ascertain breast feeding practices, contraceptive usage, as well as potential risk factors for endometrial cancer. We observed a lower risk of endometrial cancer associated with oral contraceptive (OC) and a higher risk associated with higher body mass index (BMI), and older ages at first and last delivery. Gravidity reduced odds ratio (OR) for endometrial cancer to 0.34 (95% confidence interval [CI] 0.13-0.92). Compared with parous women who had never breastfed, the multivariate OR for women with a history of breastfeeding was 0.37 (95% CI, 0.17-0.82). Additionally, a greater lapse of time since breastfeeding increased OR for endometrial cancer by over three times. In conclusion, the present study has indicated that breastfeeding reduces the risk of endometrial cancer in Japanese women.     

乳腺癌患者化疗期症状群困扰风险预测模型的构建与评价

目的 构建化疗期乳腺癌患者自我报告症状群困扰高风险预测模型并评价模型的预测性能。方法 采用便利抽样法,选取2019年10月—2021年5月在上海市、山东省、江苏省、浙江省4所三级甲等医院接受化疗并符合纳入标准的乳腺癌患者647例,按5折交叉验证法以8∶2的比例随机分为建模组和验证组。在建模组中采用随机森林算法构建,在验证组中采用受试者操作特征曲线、Hosmer-Lemeshow拟合优度检验、校准曲线以及决策曲线综合评价模型的预测性能,最后对各影响因素进行重要性排序。结果 乳腺癌患者高症状困扰发生率建模组为33.27%,验证组为29.23%。预测模型的受试者操作特征曲线下面积为0.91,灵敏度为65.8%,特异度为93.5%;Hosmer-Lemeshow拟合优度检验P=0.136;决策曲线显示高于参考线。身体心像、自我效能感、经济负担等为最主要的预测因子。结论 基于随机森林算法构建的预测模型具有良好的预测性能,对识别症状困扰高风险的乳腺癌患者有重要意义。     

HR阳性乳腺癌常用复发风险预测工具研究现状

乳腺癌是危害女性健康的严重恶性肿瘤,激素受体(hormone receptor, HR)阳性为最常见的分子亚型,由于乳腺癌的异质性患者术后复发风险各异,因而需要临床医生准确分析患者的不同预后提出个性化治疗策略。目前使用较为广泛的HR阳性乳腺癌术后复发风险预测工具有多基因检测工具、基于临床病理因素开发的预后模型,例如21基因检测评分、4项免疫组化评分等,基于影像特征建立的预后模型也逐渐在临床普及,临床实践中依据这类预测工具可得到患者的术后复发风险预测值,借此指导患者的个体化临床诊疗方案,以进一步改善患者生存质量,提高总生存期。     

Development and validation study of the breast cancer risk appraisal for Korean women

The purpose of the present study was to develop and validate breast cancer risk factors, which can be used to identify women who are at a high risk of developing breast cancer. Fourteen risk factors for breast cancer were identified from extensive literature reviews and in consultation with a panel of experts. A case-control study was conducted, which aimed to validate these 14 risk factors. Cases were selected from four university hospitals in Korea and controls were selected from health screening centers in Korea. Interviews were used to obtain exposure history of each participant to the 14 risk factors. Group differences between the cases and controls were analyzed using a chi-squared test and a logistic regression method. Among the 14 risk factors, six were identified as significant: meat consumption more than once a week (odds ratio [OR] = 1.56, confidence interval [CI] = 1.32-1.85), breast disease experience (OR = 3.08, CI = 1.49-6.37), less than two children (OR = 1.61, CI = 1.09-2.35), family history of breast cancer (OR = 8.99, CI = 3.89-20.76), and no breast-feeding experience (OR = 3.08, CI = 1.41-3.85). Based on the OR, the risk scores were calculated by the absolute size of the OR having a total of 100 points.     

Identifying risk factors for imminent death in cancer patients with acute dyspnea

A substantial proportion of cancer patients presenting to an emergency center (EC) or clinic with acute dyspnea survives fewer than 2 weeks. If these patients could be identified at the time of admission, physicians and patients would have additional information on which to base decisions to continue therapy to extend life or to refocus treatment efforts on palliation and/or hospice care alone. The purpose of this study was to identify risk factors for imminent death (survival 相似文献   

子宫内膜异位症的发病相关因素研究

目的探讨子宫内膜异位症（EMS）的发病相关因素。方法纳入301例因腹腔镜手术住院的患者,进行问卷调查,比较EMS组患者与非EMS组患者月经、疼痛症状、孕产史、既往病史、日常生活和工作等情况,对EMS发病相关危险因素行多因素Logistic回归分析。结果单因素分析显示,EMS与非EMS患者在月经行经时间、月经量、月经周期、痛经、经期排便痛、不孕史、卵巢囊肿病史、多囊卵巢综合征病史上比较差异有统计学意义（P均〈0．05）。两组患者在初潮年龄、月经规律性、性交痛、平时盆腔痛、怀孕次数、生产次数、流产次数、异位妊娠次数、剧烈运动史、吸烟史以及饮酒史上比较差异无统计学意义（P均〉0．05）。多因素Logistic回归分析显示,月经量多、痛经、卵巢囊肿病史与EMS发病呈正相关,月经周期延长与EMS发病呈负相关（P均〈0．05）。结论EMS危险因素包括月经量多、痛经、卵巢囊肿病史、月经周期缩短,临床医疗工作者遇到以上症状的患者。应注意排除EMS。     

Identifying and counseling women at increased risk for breast cancer

Women at increased risk for breast cancer should be identified and counseled about options for risk reduction. Identifying such women is simplified with use of the National Cancer Institute Risk Assessment tool, a computer-based tool that incorporates information on 6 risk factors for estimating an individual's risk of developing breast cancer. However, the tool does not incorporate all known or possible risk factors and may underestimate risk, particularly among women with a complex family history of breast cancer for whom alternative models of risk assessment are more appropriate. Women found to have an increased risk of breast cancer should be counseled about options for management, including close surveillance, lifestyle modifications, chemoprevention with tamoxifen, enrollment in a breast cancer prevention clinical trial, and prophylactic mastectomy and/or oophorectomy. In the absence of consensus about which risk level is best suited to which option, decisions about risk reduction depend as much on an individual's priorities and risk aversion as on numerical risk estimates.     

The psychosocial aspects of breast cancer

Few issues prepare women to cope with the multitude of problems that confront them when diagnosed with breast cancer. The provision of appropriate treatment requires that health care professionals attend to the emotional, social, and other nonmedical functioning of the woman and her family. Nurse practitioners play a central role in the delivery of medical care. This article describes the typical response of women to breast cancer and factors associated with risk for the development of comorbid psychological and adjustment problems. Pragmatic suggestions to guide nurse practitioners in assisting patients and their families cope with breast cancer are provided, as well as indicators for referral to a mental health professional.     

Single nucleotide polymorphisms in the homologous recombination repair genes and breast cancer risk in Polish women

Genetic polymorphisms in homologous recombination repair genes that can lead to protein haploinsufficiency are generally associated with increased cancer risk. The aim of the present study was to evaluate associations between the risk of breast cancer and single nucleotide polymorphisms in the genes, encoding three key proteins of the homologous recombination repair: RAD51 (the human homologue of the E. coli RecA protein), X-ray repair cross-complementing group (XRCC) 2 and XRCC3. The polymorphisms studied were G135C of the RAD51 gene (c. -98 G>C; rs1801320), Arg188His of the XRCC2 gene (c. 563 G>A; rs3218536), and Thr241Met of the XRCC3 gene (c. 722 C>T; rs861539). Each polymorphism was genotyped by the PCR-RFLP (restriction fragment-length polymorphism) method in 700 Polish female patients with sporadic breast cancer and in 708 cancer-free women, who served as controls. In the present study, we showed the association between RAD51 G135C polymorphism and the incidence of breast cancer (p < 0.0001), but found no significant association with XRCC2 Arg188His or XRCC3 Thr241Met polymorphism. Instead, significant association was identified between XRCC2 Arg188His or XRCC3 Thr241Met polymorphism and breast cancer progression, assessed by the histological grading. However, each of these three polymorphisms was not associated with the tumor size or the lymph node metastases. This study provides evidence that links single nucleotide polymorphisms of RAD51 and XRCC2/3 genes with the risk of breast cancer in Polish women. In conclusion, RAD51 G135C, XRCC2 Arg188His and XRCC3 Thr241Met polymorphisms may be regarded as predictive factors of sporadic breast cancer in female population.     

Assessing breast cancer risk: genetic factors are not the whole story

Genetic syndromes that convey a significant risk of breast cancer are responsible for a small but significant percentage of these cancers. However, the vast majority of breast cancers occur in women with no family history of the disease. Nongenetic risk factors include age, previous breast disease, breast tissue density, radiation exposure, and lifestyle factors, such as weight, exercise, and alcohol consumption. In this article, the authors outline genetic and other risk factors for breast cancer, explore risk-reduction strategies, and encourage primary care physicians to assess breast cancer risk in all their patients.     

乳腺癌患者血清抵抗素、脂联素和瘦素水平及其临床意义

目的了解乳腺癌患者血清中抵抗素、脂联素、瘦素及血脂变化及临床意义。方法测定90例乳腺癌患者（48例未绝经,42例已绝经）及50名健康对照者血清抵抗素、脂联素、瘦素、空腹血糖（FBG）及血脂。结果乳腺癌患者脂联素及高密度脂蛋白胆固醇（HDL-C）显著低于对照组（P〈0.01或P〈0.05）,抵抗素、瘦素、FBG及三酰甘油（TG）均明显增加（P〈0.01或P〈0.05）。但抵抗素、脂联素及瘦素在未绝经乳腺癌患者与健康对照组之间差异无统计学意义（P〉0.05）。有淋巴结转移的乳腺癌患者抵抗素、脂联素及瘦素水平与无淋巴结转移乳腺癌患者间差异有统计学意义（P〈0.01）。逐步回归分析,脂联素及HDL-C的降低,瘦素和抵抗素的升高将会增加罹患乳腺癌的风险。血清脂联素降低和瘦素的增加与乳腺癌患者淋巴结的转移呈现相关性。结论血清脂联素水平的降低和抵抗素及瘦素水平的升高是患乳腺癌的危险因素。血清中较低的脂联素和较高的瘦素水平是乳腺癌转移的危险因素。