Intake of Soy Products and Other Foods and Gastric Cancer Risk: A Prospective Study

Ko, Kwang-Pil,Park, Sue K.,Yang, Jae Jeong,Ma, Seung Hyun,Gwack, Jin,Shin, Aesun,Kim, YeonJu,Kang, Daehee,Chang, Soung-Hoon,Shin, Hai-Rim,Yoo, Keun-Young Japan Epidemiological Association 2013 Journal of epidemiology Vol.23 No.5

<P><B>Background</B></P><P>Gastric cancer, the most common cancer in the world, is affected by some foods or food groups. We examined the relationship between dietary intake and stomach cancer risk in the Korean Multi-Center Cancer Cohort (KMCC).</P><P><B>Methods</B></P><P>The KMCC included 19 688 Korean men and women who were enrolled from 1993 to 2004. Of those subjects, 9724 completed a brief 14-food frequency questionnaire at baseline. Through record linkage with the Korean Central Cancer Registry and National Death Certificate databases, we documented 166 gastric cancer cases as of December 31, 2008. Cox proportional hazard models were used to estimate relative risks (RRs) and 95% CIs.</P><P><B>Results</B></P><P>Frequent intake of soybean/tofu was significantly associated with reduced risk of gastric cancer, after adjustment for age, sex, cigarette smoking, body mass index, alcohol consumption, and area of residence (<I>P</I> for trend = 0.036). We found a significant inverse association between soybean/tofu intake and gastric cancer risk among women (RR = 0.41, 95% CI: 0.22–0.78). Men with a high soybean/tofu intake had a lower risk of gastric cancer, but the reduction was not statistically significant (RR = 0.77, 95% CI: 0.52–1.13). There was no interaction between soybean/tofu intake and cigarette smoking in relation to gastric cancer risk (<I>P</I> for interaction = 0.268).</P><P><B>Conclusions</B></P><P>Frequent soybean/tofu intake was associated with lower risk of gastric cancer.</P>

Soybean Product Intake Modifies the Association between Interleukin-10 Genetic Polymorphisms and Gastric Cancer Risk

Ko, Kwang-Pil,Park, Sue K.,Cho, Lisa Y.,Gwack, Jin,Yang, Jae Jeong,Shin, Aesun,Kim, Cheong Sik,Kim, Yeonju,Kang, Daehee,Chang, Soung-Hoon,Shin, Hai-Rim,Yoo, Keun-Young Oxford University Press 2009 The Journal of nutrition Vol.139 No.5

<P>In this study, our aim was to investigate the association of inflammation-related genetic polymorphisms and gastric cancer risk and to examine whether the combined effect of soybean product intake modified cancer risk. Eighty-four incident gastric cancer cases and 336 matched controls were selected from the Korean Multi-Center Cancer Cohort. We selected 14 single nucleotide polymorphisms (SNP) from 5 genes [interleukin (IL)-1beta, IL-2, IL-4, IL-8, and IL-10] and used unconditional logistic regression model to calculate the odds ratios (OR) and 95% CI adjusting for H. pylori seropositivity, smoking, age, sex, enrollment year, and residential area. The risk for gastric cancer in relation to genetic polymorphisms and haplotypes were assessed according to soybean product intake levels. Although no single SNP effect was found, the combined effect between IL-10 gene variants of -592 GG/GA, -819 TC/CC, or -1082 AG/GG and low intake of soybean products had an increased risk for gastric cancer compared with the group with no risk gene variants and a high intake of soybean products (OR [95% CI] = 2.82 [1.04-7.62], 2.75 [1.02-7.44], and 4.34 [1.51-12.5], respectively). Among the low-soybean product intake group, IL-10 CCG haplotype had an increased risk of gastric cancer (OR = 3.38 [1.40-8.13]) relative to the ATA haplotype. Our results suggest that the association between IL-10 genetic polymorphisms and gastric cancer risk was modified by soybean product intake.</P>

Isoflavones from phytoestrogens and gastric cancer risk: a nested case-control study within the Korean Multicenter Cancer Cohort.

Ko, Kwang-Pil,Park, Sue K,Park, Boyoung,Yang, Jae Jeong,Cho, Lisa Y,Kang, Chungwon,Kim, Cheong Sik,Gwack, Jin,Shin, Aesun,Kim, Yeonju,Kim, Jeongseon,Yang, Han-Kwang,Kang, Daehee,Chang, Soung-Hoon,Shin American Association for Cancer Research 2010 Cancer Epidemiology, Biomarkers & Prevention Vol.19 No.5

<P>BACKGROUND: The role of soybean products in gastric cancer risk is not clear in epidemiologic studies due to measurement error from dietary intake questionnaires and due to different degrees of bias according to study design. To examine the association between soybean products and gastric cancer risk, we measured phytoestrogen biological markers in a nested case-control study. METHODS: The study population was composed of 131 cases and 393 matched controls within the Korean Multicenter Cancer Cohort. The concentrations of the four biomarkers in the plasma samples were measured using time-resolved fluoroimmunoassay. Conditional and unconditional logistic regression models were used to compute the odds ratio (OR) and 95% confidence intervals (CI). RESULTS: Median plasma concentrations of genistein (229 nmol/L for controls, 181.8 nmol/L for cases; P=0.07) and daidzein (131.2 nmol/L for controls, 80.5 nmol/L for cases; P=0.04) in cases were lower than in controls, whereas equol concentrations were similar. Compared with the reference group, gastric cancer risk decreased in the highest groups for genistein (OR, 0.54; 95% CI, 0.31-0.93) and daidzein (OR, 0.21; 95% CI, 0.08-0.58). Higher equol concentrations were associated with a decreased risk for gastric cancer (OR, 0.50; 95% CI, 0.27-0.90). The combination of the highest concentrations for each isoflavone category was associated with a 0.09-fold decreased risk for gastric cancer compared with the combination of the lowest concentrations for each category. There was no association between plasma lignan concentrations and gastric cancer. CONCLUSIONS: High serum concentrations of isoflavones were associated with a decreased risk for gastric cancer. IMPACT: These results suggest a beneficial effect of high soybean product intake for gastric cancer risk.</P>

Dietary intake and breast cancer among carriers and noncarriers of <i>BRCA</i> mutations in the Korean Hereditary Breast Cancer Study

Ko, Kwang-Pil,Kim, Sung-Won,Ma, Sung Hyun,Park, Boyoung,Ahn, Younjhin,Lee, Jong Won,Lee, Min Hyuk,Kang, Eunyoung,Kim, Lee Su,Jung, Yongsik,Cho, Young Up,Lee, ByoungKil,Lin, Jennifer H,Park, Sue K American Society for Clinical Nutrition 2013 The American journal of clinical nutrition Vol.98 No.6

<P><B>Background:</B> Soy intake is associated with a lower risk of breast cancer. However, it is unclear whether the same reduction in risk associated with high soy intake is also applicable to familial or genetic breast cancer.</P><P><B>Objective:</B> The aim of this study was to assess the dietary factors among carriers and noncarriers of <I>BRCA</I> mutations in the Korean Hereditary Breast Cancer Study (KOHBRA).</P><P><B>Design:</B> The KOHBRA Study is an ongoing project composed of affected breast cancer patients and familial members of breast cancer cases with <I>BRCA</I> mutations. To assess the association between dietary diversity and breast cancer risk, an HR was estimated by comparing affected subjects with their familial nonaffected members. To assess the interaction between the combination of <I>BRCA</I> mutation and diet diversity, the case-only OR (COR) was estimated by comparing <I>BRCA</I> mutation carriers and noncarriers only in affected subjects.</P><P><B>Results:</B> Soy product intake was associated with a lower risk of breast cancer in carriers (HR: 0.39; 95% CI: 0.19, 0.79 for the highest quartile). The highest quartile of meat intake was associated with a higher risk of breast cancer regardless of <I>BRCA</I> mutation in carriers (HR: 1.97; 95% CI: 1.13, 3.44) and noncarriers (95% CI: 1.41; 1.12, 1.78). The associations of meat intake and soybean intake for breast cancer were more prominent in <I>BRCA2</I> mutation carriers. In the analysis with only cases, the highest quartile of soy intake, but not meat intake, was associated with <I>BRCA</I>-related breast cancer (COR: 0.57; 95% CI: 0.36, 0.91).</P><P><B>Conclusion:</B> Our study suggests that soy product consumption is associated with lower breast cancer risk and it had an interaction with <I>BRCA</I> mutation. This trial was registered at clinicaltrials.gov as NCT00595348.</P>

Plasma phytoestrogens concentration and risk of colorectal cancer in two different Asian populations

Ko, Kwang-Pil,Yeo, Yohwan,Yoon, Ji-Hye,Kim, Cheong-Sik,Tokudome, Shinkan,Ngoan, Le Tran,Koriyama, Chihaya,Lim, Young-Khi,Chang, Soung-Hoon,Shin, Hai-Rim,Kang, Daehee,Park, Sue K.,Kang, Chul Hwan,Yoo, Elsevier 2018 Clinical nutrition Vol.37 No.5

<P><B>Summary</B></P> <P><B>Background & aims</B></P> <P>To evaluate the relationship between phytoestrogen and colon cancer risk, we quantified plasma isoflavones (Genistein and Daidzein) and lignan (enterolactone) in a Korean nested case-control study and conducted replication study in a Vietnamese case-control study.</P> <P><B>Methods</B></P> <P>Study populations of 101 cases and 391 controls were selected from the Korean Multicenter Cancer Cohort which was constructed from 1993 to 2004. For replication study, Vietnamese hospital-based case-control subjects of 222 cases and 206 controls were selected from 2003 to 2007. The concentrations of plasma genistein, daidzein, and enterolactone were quantified by liquid chromatography-mass spectrometry. Logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CIs), and meta-analysis was conducted to estimate combined ORs (CORs) and 95% Cis of Korean and Vietnamese population in 2014.</P> <P><B>Results</B></P> <P>Genistein showed a continual decrease in colorectal cancer risk according to level up of the concentration categories in Korean and Vietnamese population (<I>P</I> for trend = 0.032, and 0.001, respectively) and a significantly decreased risk was found at the highest concentration of genistein and daidzein (for the highest category compared to the lowest: COR (95% CI) = 0.46 (0.30–0.69), and COR (95% CI) = 0.54 (0.36–0.82)). When the study population was stratified, the beneficial relationship of genistein with colorectal cancer was observed regardless of sex and anatomical subtype. However, enterolacton level was not associated with colorectal cancer risk.</P> <P><B>Conclusions</B></P> <P>High plasma levels of isoflavones had relationship with a decreased risk of colorectal cancer, regardless of different ethnic background.</P>

Isoflavones: Chemistry, Analysis, Functions and Effects on Health and Cancer

Ko, Kwang-Pil Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

Isoflavones are phytoestrogens and natural plant compounds which are similar to 17-${\beta}$-estradiol in chemical structure. It is known that they can act as estrogen agonists or antagonists, depending on endocrine estrogenic levels, but actions of isoflavones are rather complex due to large number of variables such as chemical structures and mechanisms. Some hypotheses on biological mechanisms have not satisfactorily been confirmed to date and human epidemiological and experimental studies have been relatively limited. Nevertheless, isoflavones and isoflavone rich foods have become a focus onf interest due to positive health benefits on many diseases, especially prevention of hormone-related cancers, cardiovascular disease, osteoporosis, and adverse postmenopausal symptoms, and improvement of physiological condition such as maintaining cognitive function. This review provides an overview of chemistry, analytical techniques (focused on human biospecimens), functions including biological mechanisms, and effects of isoflavones, on the basis of the available meta-analysis and review articles and some original articles, on health and cancer.

In Korean Women, High Plasma Level of Enterolactone Reduces Risk of Type 2 Diabetes and This Effect is Enhanced in Equol-Producers

Kwang-Pil Ko,En-Joo Jung,Younjhin Ahn,Seon-Joo Park,Young-Khi Lim 건강기능식품미래포럼 2022 건강기능식품미래포럼 학술지 Vol.2 No.4

Diabetes, if left untreated, can cause many health complications. Type 2 diabetes is known to be primarily due to lifestyle and thus, efforts have been made to reduce its risk by diet particularly of vegetables containing various antioxidants. In the present study, this possibility was investigated by examining association between the plasma level of enterolactone, a metabolite of food lignans and the risk of type 2 diabetes and the association was compared between producers and non-producers of equol, a metabolite of soy isoflavone. The study population was composed of 693 cases and 698 matched controls within the Korean Genome Epidemiology Study. Logistic regression models were used to compute the odds ratio (OR) and 95% confidence intervals (CI). Stratified analysis was done to examine the association between plasma enterolactone concentration and risk of type 2 diabetes, and then, this association was examined in terms of sex and status of equol producing ability. In female, compared with the reference level, a marginally significant risk reduction was found at the highest concentration of enterolactone (for the highest category: OR, 0.68; 95% CI, 0.46–1.01). In equol producers among women, the highest concentration of enterolactone significantly decreased the risk of type 2 diabetes (OR, 0.58; 95% CI, 0.34–0.96). In equol non-producers among women, however, the concentration of enterolactone was not associated with the risk of type 2 diabetes. In male, enterolactone concentration was not associated with risk of type 2 diabetes regardless of equol producing status. In conclusion, high plasma concentrations of enterolactone were associated with a decreased risk of type 2 diabetes particularly, in equol producing female.

인터페이스 디자인에서 시지각 정보와 인지 프로세스의 상관관계에 관한 연구

고광필(Ko Kwang-pil),김미아(Kim Mi-ah) 한국디자인학회 2001 디자인학연구 Vol.- No.41

Biomarker 연구 설계와 분석

고광필 ( Kwang-pil Ko ) 대한간학회 2018 임상연구방법론워크숍 Vol.2018 No.1

Original Article : Rifaximin Plus Levofloxacin-Based Rescue Regimen for the Eradication of Helicobacter pylori

( Sang Pil Yun ),( Han Gyung Seon ),( Chang Soo Ok ),( Kwang Ho Yoo ),( Min Kyung Kang ),( Won Hee Kim ),( Chang Il Kwon ),( Kwang Hyun Ko ),( Seong Gyu Hwang ),( Pil Won Park ),( Sung Pyo Hong ) The Editorial Office of Gut and Liver 2012 Gut and Liver Vol.6 No.4

Background/Aims: This study assessed the efficacy of a rifaximin plus levofloxacin-based rescue regimen in patients that had failed both triple and quadruple standard regimens for the eradication of Helicobacter pylori. Methods: We treated patients for H. pylori between August 2009 and April 2011. The triple regimen consisted of combined treatment with amoxicillin, clarithromycin, and pantoprazole for 1 week. For failed cases, a quadruple regimen of tetracycline, metronidazole, bismuth dicitrate, and lansoprazole for 1 week was administered. The rescue regimen for persistently refractory cases was rifaximin 200 mg t.i.d., levofloxacin 500 mg q.d., and lansoprazole 15 mg b.i.d. for 1 week. Results: In total, 482 patients were enrolled in this study. The eradication rates associated with the first and second regimens were 58% and 60%, respectively. Forty-seven out of 58 patients who failed with the second-line regimen received rifaximin plus levofloxacin-based third-line therapy. The eradication rate for the third regimen was 65%. The cumulative eradication rates were 58%, 85%, and 96% for each regimen, respectively. Conclusions: A rifaximin plus levofloxacin-based regimen could be an alternative rescue therapy in patients with resistance to both triple and quadruple regimens for the eradication of H. pylori. (Gut Liver 2012;6:452-456)