• Korean Journal of Clinical Pharmacy
• /
• v.25 no.3
• /
• pp.131-137
• /
• 2015

Background: The protective effect of metformin against breast cancer is inconclusive. Objective: To evaluate the effect of metformin on breast cancer risk and mortality in patients with type 2 diabetes. Method: A comprehensive literature search was performed for pertinent articles published prior to June 30, 2014, using PubMed and EMBASE. Study heterogeneity was estimated with $I^2$ statistic. The data from the included studies were pooled and weighted by random-effects model. The quality of each included study was assessed on the basis of the 9-star Newcastle-Ottawa Scale and publication bias was evaluated by visual inspection of a funnel plot. Results: Ten studies were included in the meta-analysis of the association of metformin and breast cancer risk. By synthesizing the data from the studies, the pooled odds ratio (OR) was 0.72 (95% CI: 0.59, 0.87) (p = 0.0005). Three cohort studies were included for meta-analysis of the association between metformin and breast cancer-related mortality. Metformin was associated with a significant decrease in mortality (Risk ratio: 0.68; 95% CI: 0.51, 0.90, p = 0.007). Conclusion: The present meta-analysis suggests that metformin appears to be associated with a lower risk of breast cancer incidence and mortality in patients with type 2 diabetes.

• Journal of Preventive Medicine and Public Health
• /
• v.48 no.5
• /
• pp.225-230
• /
• 2015

Objectives: The epidemiological characteristics of breast cancer incidence by age group in Korean women are unique. This systematic review aimed to investigate the association between hormone replacement therapy (HRT) and breast cancer risk in Korean women. Methods: We searched electronic databases such as KoreaMed, KMbase, KISS, and RISS4U as well as PubMed for publications on Korean breast cancer patients. We also conducted manual searching based on references and citations in potential papers. All of the analytically epidemiologic studies that obtained individual data on HRT exposure and breast cancer occurrence in Korean women were selected. We restricted the inclusion of case-control studies to those that included age-matched controls. Estimates of summary odds ratio (SOR) with 95% confidence intervals (CIs) were calculated using random effect models. Results: One cohort and five case-control studies were finally selected. Based on the heterogeneity that existed among the six studies (I-squared=70.2%), a random effect model was applied. The summary effect size of HRT history from the six articles indicated no statistical significance in breast cancer risk (SOR, 0.983; 95% CI, 0.620 to 1.556). Conclusions: These facts support no significant effect of HRT history in the risk of breast cancer in Korean women. It is necessary to conduct a pooled analysis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.3
• /
• pp.1175-1179
• /
• 2015

Background: Expression of matrix metalloproteinases (MMPs) is up-regulated in human cancers. The aim of present study was to investigate the role of MMP-9 C-1562T polymorphism and its interaction with MMP-2 C-735T polymorphism in susceptibility to breast cancer in a population from Western Iran with Kurdish ethnic background. Materials and Methods: The study sample of 205 individuals consisted of 101 breast cancer patients and 104 healthy subjects. MMP-9 C-1562T and MMP-2 C-735T variants were identified using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: Among 67.4% of studied patients the breast cancer developed in the third and forth decades of the life. The frequency of MMP-9 T allele was 17.3% in patients and 10.1% in controls. The presence of T allele significantly increased the risk of breast cancer by 1.87-fold [OR=1.87 (95% CI 1.05-3.33, p=0.035)]. The frequency of MMP-9 CT+TT genotype tended to be higher in those patients with a family history of cancer in first degree-relatives (36.8%) than those without a family history (28.3%, p=0.37). We observed an interaction between the MMP-9 -1562 T allele with MMP-2 -735 C allele that significantly increased the risk of breast cancer [OR=1.42 (95% CI 1.02-1.98, p=0.036)]. Conclusions: The present study demonstrated that MMP-9 C-1562T polymorphism alone and in combination with MMP-2 C-735T polymorphism increased the risk of breast cancer that might be a useful biomarker in identifying women at risk of developing breast cancer. Also, this study revealed that in most women from Western Iran breast cancer presents in third and fourth decades of life.

• Korean Journal of Health Education and Promotion
• /
• v.26 no.1
• /
• pp.15-26
• /
• 2009

Objectives: The current study evaluated the effects of an integrated breast health program according to levels of breast cancer risk appraisal on knowledge on breast cancer, early detection behaviors, and diet patterns and attitudes in Korean healthy women. Method: A nonequivalent control group pre-posttest design was used. A total of 413 women aged 40-59, registering at the Life Long Health Center in two cities, were classified into intervention groups of 179 women and control groups of 234 women. The integrated breast health program included education, counseling on breast cancer, early detection behaviors, and appropriate diet with multimedia and individual practice session using breast models, reflecting characteristics of each level according to levels of risk appraisal. The knowledge on breast cancer, early detection behaviors, and diet were investigated using questionnaires at baseline and three months after intervention. Results: In both normal and borderline-risk group, intervention groups reported significantly higher scores of knowledge on breast cancer and higher stages of BSE behaviors than control groups. Conclusion: The results showed positive effects on knowledge and early detection behaviors of breast cancer in normal and borderline-risk groups. Further studies should investigate longitudinal effects of the intervention program on dietary change.

• Environmental Mutagens and Carcinogens
• /
• v.23 no.1
• /
• pp.23-29
• /
• 2003

To determine the frequencies of the genotypes of estrogen metabolising enzyme (CYP17, CYP1A1, CYP1B1, and COMT) and to identify the high-risk genotypes of these metabolic enzymes to breast cancer in Korean, the author has analysed 115 breast cancer patients and corresponding age and sex matched heathy controls using polymerase chain reaction-restiction fragment length polymorphism (PCR-RFLP). A2/A2 genotype in CYP17 polymorphism, m2/m2 genotype in CYP1A1 polymorphism, and Val/Val genotype in CYP1B1 had 0.95, 1.40 and 0.76 relive risks to breast cancer comparing with reference genotypes of each polymorphism, respectively. Among the genotypes of COMT enzyme polymorphism, L/H and L/L genotypes had 0.97 and 1.54 relative risks to breast cancer, respectively. According to the number of high risk genotype, the patients with one or two putative high risk genotypes had 0.95 and 1.94 relative risks to breast cancer, respectively. This study have demonstrated the unique frequency of genotypes of estrogen metabolizing enzyme in Korean healthy women, which will provide the basic data and insights to study the estrogen related conditions in Korean women including breast and endometrial cancers. And it also indicates that the well-known high risk genotypes of estrogen metabolizing enzymes are not significantly associated with the development of breast cancer in Korean women.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3431-3436
• /
• 2012

Objective: X-ray cross-complementing group 4 (XRCC4) is a major repair gene for DNA double-strand breaks (DSB) in the non-homologous end-joining (NHEJ) pathway. Several potentially functional polymorphisms of the XRCC4 gene have been implicated in breast cancer risk, but individually published studies showed inconclusive results. The aim of this meta-analysis was to investigate the association between XRCC4 polymorphisms and the risk of breast cancer. Methods: The MEDLINE, EMBASE, Web of science and CBM databases were searched for all relevant articles published up to June 20, 2012. Potential associations were assessed with comparisons of the total mutation rate (TMR), complete mutation rate (CMR) and partial mutation rate (PMR) in cases and controls. Statistical analyses were performed using RevMan 5.1.6 and STATA 12.0 software. Results: Five studies were included with a total of 5,165 breast cancer cases and 4,839 healthy controls. Meta-analysis results showed that mutations of rs2075686 (C>T) and rs6869366 (G>T) in the XRCC4 gene were associated with increased risk of breast cancer, while rs2075685 (G>T) and rs10057194 (A>G) might decrease the risk of breast cancer. However, rs1805377 (A>G), rs1056503 (G>T), rs28360317 (ins>del) and rs3734091 (A>G) polymorphisms of XRCC4 gene did not appear to have an influence on breast cancer susceptibility. Conclusion: Results from the current meta-analysis suggest that the rs2075685 (G>T) and rs6869366 (G>T) polymorphisms of the XRCC4 gene might increase the risk of breast cancer, whereas rs2075685 (G>T) and rs10057194 (A>G) might be protective factors.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.4
• /
• pp.2075-2081
• /
• 2016

Background: Breast cancer incidence and mortality rates are increasing in North-Eastern Brazil and the patients with the disease often presented at advanced stages. The present study was focused on identifying variables that affect women's frequency of breast self- examination (BSE) performance. Materials and Methods: Data on BSE, socio-economic parameters and risk factors for breast cancer were obtained from 417 women from a community in North-Eastern Brazil by a self-informant method. To identify independent variables that affect frequency of BSE, nominal logistic regression analysis was performed. Results: Of 417 women, 330 (79.3%) reported performing BSE. Compared to high-income women, BSE performance by low-income women every month was 7.69 (OD=0.130; CI 95%: 0.044- 0.0386; p=0.000) times lower. Women who did not live in a stable union performed BSE each month 2.73 (OD=0.366; CI 95%: 0.171-0.782; p=0.010) less often than those living in a stable union. BSE performance every month and every six months or every year by women with poor knowledge about risk factors for breast cancer was 3.195 (OD=0.313; CI 95%: 0.141- 0.695; p=0.004) times and 2.028 (OD=0.493; CI 95%: 0.248- 0.979; p=0.043) times lower, compared to women with good knowledge. Participants who had a close relative with cancer performed BSE every month and every six months or every year 2.132 (OD=0.469; CI 95%: 0.220-0.997; p=0.049) times and 2.337 (OD=0.428; CI 95%: 0.219-0.836; p=0.013) times less often, compared to those women without close relatives with cancer. Conclusions: The results of this study indicated that income, marital status, knowledge about risk factors and having a close relative with breast cancer, affect the frequency of BSE performance. Information about risk factors in public health campaigns could additionally strengthen avoidance behaviour and also motivate BSE performance.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.10
• /
• pp.5105-5111
• /
• 2012

Background: Published data on the association between single nucleotide polymorphisms (SNPs) in the ESR1 gene and breast cancer susceptibility are inconclusive or controversial. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to derive a more precise estimation of this relationship. Methods: A literature search of Pubmed, Embase, Web of science and CBM databases was conducted from inception through September 1th, 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. Results: A total of five studies including 1,678 breast cancer cases and 1,678 general population controls in Asian populations were involved in this meta-analysis. When all the eligible studies were pooled into the meta-analysis, the higher transcriptional activity variant allele T of ESR1 PvuII (C>T) (rs2234693) in pre-menopausal breast cancer women showed a significant relation to increased risk (OR = 1.13, 95%CI: 1.01-1.28, P = 0.040) in contrast to their post-menopausal counterparts which showed non-significant increased risk (OR = 1.01, 95%CI: 0.87-1.18, P = 0.858). Nevertheless, no significant association between ESR1 XbaI (A>G) (rs9340799) polymorphism and the risk of breast cancer was observed in pre-menopausal and post-menopausal individuals. Conclusion: Based on a homogeneous Asian population, results from the current meta-analysis indicates that the ESR1 PvuII (C>T) polymorphism places pre-menopausal breast cancer women at risk for breast cancer, while ESR1 XbaI (A>G) polymorphism is not likely to predict the risk of breast cancer.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.11
• /
• pp.4411-4416
• /
• 2014

Breast cancer is the most common cancer in females all over the world with approximately one million new cases each year as well as one of second leading causes of death among females. In Pakistan, the most frequently diagnosed cancer among females is also breast cancer, accounting for nearly one in nine female patients. Its incidence in Pakistan is 2.5 times higher than that in neighboring countries like Iran and India. The risk factors associated with breast cancer are age, family history, early menarche, intake of combined estrogen and progestin menopausal hormones, alcohol consumption, physical inactivity, low socioeconomic status and lack of awareness regarding the disease. This mini-review article aims to provide awareness about breast cancer as well as an updated knowledge about the prevalence, risk factors and disease knowledge of breast cancer in Pakistan.

• International Journal of Human Ecology
• /
• v.4 no.2
• /
• pp.101-106
• /
• 2003

The relationship between fat intake and breast cancer has been debated for a long period of time. Animal, ecological, and case-control studies have supported that dietary fat increases breast cancer risk. However, cohort studies have not support any strong association between dietary fat intake and breast cancer risk. It has not been clear whether fat per se or some specific type of fat is responsible for the increased risk. Recently, a few cohort studies have found some positive association between specific types of fat intake, but not overall fat intake and breast cancer risk. In this review, the findings from previous studies will be summarized with advantages and disadvantages of different types of study design and recent findings will be introduced.