Osteopontin and latent-TGF ß binding-protein 2 as potential diagnostic markers for HBV-related hepatocellular carcinoma.

Chronic Hepatitis B (HB) is the main risk factor for chronic liver disease (CLD) and hepatocellular carcinoma (HCC) in many low-resource countries, where diagnosis is constrained by lack of clinical, histopathological and biomarker resources. We have used proteomics to detect plasma biomarkers that outperform α-Fetoprotein (AFP), the most widely used biomarker for HCC diagnosis in low-resource contexts. Deep-plasma proteome analysis was performed in HCC patients, patients with CLD and in HB-carrier controls from Thailand (South-East Asia) and The Gambia (West-Africa). Mass spectrometry profiling identified latent-transforming growth factor ß binding-protein 2 (LTBP2) and Osteopontin (OPN) as being significantly elevated in HCC versus CLD and controls. These two proteins were further analyzed by ELISA in a total of 684 plasma samples, including 183 HCC, 274 CLD and 227 asymptomatic controls. When combined, LTBP2 and OPN showed an area under the receiver operating curve of 0.85 in distinguishing HCC from CLD in subjects with AFP <20 ng/mL. In a prospective cohort of 115 CLD patients from Korea, increased plasma levels of LTBP2 and/or OPN were detected in plasma collected over 2 years prior to diagnosis in 21 subjects who developed HCC. Thus, the combination of LTBP2 and OPN outperformed AFP for diagnosis and prediction of HCC and may therefore improve biomarker-based detection of HBV-related HCC.

Genetic and environmental determinants of risk for cholangiocarcinoma in Thailand.

Cholangiocarcinoma (CCA) is a difficult cancer to diagnose in the early stage and to treat by curative resection. The incidence of CCA in the northeast of Thailand is the highest in the world. To make progress in detecting a high risk group and in the prevention and detection of CCA, we have been analyzing the risk factors for CCA. Although liver fluke infection is known to be a risk factor, there are patients who are not infected with the liver fluke and not all people infected with the liver fluke will suffer from the disease. Therefore, it is of the utmost importance to analyze the risk factors and the mechanism to prevent the disease and also to detect the disease in its early stage to save patients' lives. Through collaboration among Thai and Japanese researchers, we analyzed the genetic and environmental determinants of risks for CCA. Also, we have been trying to develop methods to detect the disease in a non-invasive way. Without repeating findings reported in various reviews on CCA, we will first discuss the environmental and genetic determinants of the risks for CCA. Second, we will discuss the properties of CCA, including the etiological agents and the mechanism of cholangiocarcinogenesis, and finally, we will discuss future approaches to prevent and cure CCA from the standpoint of evidence-based medicine. We will discuss these points by including the data from our laboratories. We would like to emphasize the importance of the genetic data, especially whole genome approaches, to understand the properties of CCA, to find a high risk population for CCA and to develop effective preventative methods to stop the carcinogenic steps toward CCA in the near future. In addition, it is of the upmost importance to develop a non-invasive, specific and sensitive method to detect CCA in its early stage for the application of modern medical approaches to help patients with CCA.

Factors influencing the stages of breast cancer at the time of diagnosis in Thai women.

BACKGROUND: Early diagnosis of breast cancer leads to early treatment therefore improving women's health. However, most Thai women are diagnosed at a late stage. OBJECTIVE: This cross-sectional correlational study was designed to explore factors influencing the diagnosis of early stage breast cancer in Thai women. METHOD: Thai women (n = 400) newly diagnosed breast cancer at all clinical stages from public hospitals in Bangkok Metropolitan completed a questionnaire about knowledge of breast cancer and screening. The questionnaire addressed pre-diagnosis data about: (1) health care provider's recommendations to undertake breast screening, (2) health coverage for mammography (MM) costs and (3) regularity of breast screening behaviors in terms of breast self-examination (BSE), clinical breast examination (CBE) and MM including stage breast cancer at diagnosis. Data analysis was determined by PASW Statistics version 18 as univariate and multivariate logistic regression. RESULTS: Health coverage for MM costs and all three behaviors were significantly related to and could predict the early stages breast cancer at diagnosis (p < 0.05): health coverage for MM costs (OR = 0.32, 95% confidence interval [CI], 0.17-0.63), BSE (OR = 8.08, CI 95%, 3.93-16.63), CBE (OR = 12.54, CI 95%, 2.29-68.65) and MM (OR = 5.89, CL 95%, 1.13-30.73). CONCLUSIONS: All three behaviors are essential and related to one another. CBE on a regular basis is the best predictor for early stages breast cancer at diagnosis in Thai context. Nurses should provide information and teach including re-check the woman's skills to perform BSE regularly.

Diagnosis of liver cancer from blood sera using FTIR microspectroscopy: a preliminary study.

FTIR microspectroscopy was applied for studying macromolecular changes in human serum samples from patients with healthy livers, and those diagnosed with liver cirrhosis or hepatocellular carcinoma (HCC). Our study demonstrated that the serum samples from HCC and cirrhotic patients could readily be discriminated from those from healthy controls based on macromolecular differences related to their lipid and protein structure. Spectral changes appeared to indicate that the secondary structure of protein from HCC sample groups contained a more distinctive ß -sheet structure and a lower lipid content compared to samples from the healthy and cirrhosis group. This was correlated with measurements of large decreases in albumin levels in serum from diseased patients. We argue that this technique shows potential as a simple, rapid, inexpensive, and non-subjective methodology for the screening patients suspected of liver disease.

Analysis of new biomarkers for cholangiocarcinoma.

Cholangiocarcinoma is one of the most serious diseases in northeast Thailand, where its incidence is reported to be the highest in the world. We tried to develop a new method to detect cholangiocarcinoma in the early stages using serum proteins. We found that after fluorescent labeling of the sugar moiety of serum proteins, a new peak was identified, which might be a promising marker for cholangiocarcinoma.

Organised colorectal cancer screening in Lampang Province, Thailand: preliminary results from a pilot implementation programme.

OBJECTIVE: Colorectal cancer (CRC) is the third-most and fifth-most common cancer in men and women, in Thailand. The increasing CRC incidence and mortality can be reduced by screening and treating adenomas and early cancers. A pilot CRC screening programme using immunochemical faecal occult blood testing (iFOBT) and colonoscopy for test-positives were implemented through the routine Government Health Services in Lampang Province, to inform the acceptability, feasibility and scaling-up of screening in Thailand. This report describes the implementation, coverage and performance indicators of this project. DESIGN: A target population aged 50-65 years was informed about and invited face to face to undergo CRC screening by community health workers (HWs). The HWs provided faecal sample collection kits and participants brought their samples to one of the primary health units or community hospitals where nurses performed iFOBT. iFOBT-positive persons were referred for colonoscopy at the Lampang cancer hospital, and endoscopic polypectomy/biopsies were performed according to the colonoscopic findings. Those with confirmed CRC received appropriate treatment. RESULTS: Of the 127 301 target population, 62.9% were screened using iFOBT between April 2011 and November 2012. Participation was higher among women (67.8%) than men (57.8%) and lower in 50-54 year-old persons than in 60-65-year-olds. Of those screened, 873 (1.1%) were found positive; positivity was higher in men (1.2%) than in women (1.0%). To date 627 (72.0%) iFOBT-positive persons have had colonoscopy in which 3.7% had CRC and 30.6% had adenomas. CONCLUSIONS: The successful implementation of the pilot CRC screening with satisfactory process measures indicate the feasibility of scaling-up organised CRC screening through existing health services in Thailand.

Cancer prevention in Asia: resource-stratified guidelines from the Asian Oncology Summit 2013.

With economic growth in Asia, cancer has become increasingly prominent as a major health problem. However, discrepancies in infrastructure, economics, and development exist within and between Asian countries. We assess means of primary and secondary prevention for cervical, breast, colorectal, and hepatocellular cancer, and offer recommendations according to resource levels. Primary prevention by health education, lifestyle modification, and avoidance of risk factors should be made available at all resource levels. When resources allow, human papillomavirus and hepatitis B vaccinations should be given to reduce the risk of cervical and hepatocellular cancer, and genetic testing should be offered to detect increased susceptibility to colorectal and breast cancer. Secondary prevention by effective yet affordable screening for precancerous lesions or by early detection of cancer should be offered, followed by appropriate treatment.

Association between TP53 R249S mutation and polymorphisms in TP53 intron 1 in hepatocellular carcinoma.

Over 100 single nucleotide polymorphisms (SNP) are validated in the TP53 tumor suppressor gene. They define haplotypes, which may differ in their activities. Therefore, mutation in cancer may occur at different rates depending upon haplotypes. However, these associations may be masked by differences in mutations types and causes of mutagenesis. We have analyzed the associations between 19 SNPs spanning the TP53 locus and a single specific aflatoxin-induced TP53 mutation (R249S) in 85 in hepatocellular carcinoma cases and 132 controls from Thailand. An association with R249S mutation (P = 0.007) was observed for a combination of two SNPs (rs17882227 and rs8064946) in a linkage disequilibrium block extending from upstream of exon 1 to the first half of intron 1. This domain contains two coding sequences overlapping with TP53 (WRAP53 and Hp53int1) suggesting that sequences in TP53 intron 1 encode transcripts that may modulate R249S mutation rate in HCC.

Association between HBX status, aflatoxin-induced R249S TP53 mutation and risk of hepatocellular carcinoma in a case-control study from Thailand.

Hepatocellular carcinoma (HCC) is associated with hepatitis B virus (HBV) chronicity and dietary exposure to aflatoxin, a mutagen targeting codon 249 of tumor suppressor TP53 (R249S mutation). Based on a case-control in Thailand, we have measured R249S and the status of HBX gene in plasma DNA of 176 cases and 133 referents. Detection of HBX complete sequences was associated with R249S in HCC with no documented prior cirrhosis but not in HCC developing in a context of cirrhosis or in non-cancer chronic liver diseases. Thus, R249S may specifically cooperate with HBX in a pathway to HCC that bypasses cirrhosis.

Aflatoxin-induced TP53 R249S mutation in hepatocellular carcinoma in Thailand: association with tumors developing in the absence of liver cirrhosis.

Primary Liver Cancer (PLC) is the leading cause of death by cancer among males in Thailand and the 3(rd) among females. Most cases are hepatocellular carcinoma (HCC) but cholangiocarcinomas represent between 4 and 80% of liver cancers depending upon geographic area. Most HCC are associated with chronic infection by Hepatitis B Virus while a G → T mutation at codon 249 of the TP53 gene, R249S, specific for exposure to aflatoxin, is detected in tumors for up to 30% of cases. We have used Short Oligonucleotide Mass Analysis (SOMA) to quantify free circulating R249S-mutated DNA in plasma using blood specimens collected in a hospital case:control study. Plasma R249S-mutated DNA was detectable at low concentrations (≥ 67 copies/mL) in 53 to 64% of patients with primary liver cancer or chronic liver disease and in 19% of controls. 44% of patients with HCC and no evidence of cirrhosis had plasma concentrations of R249S-mutated DNA ≥ 150 copies/mL, compared to 21% in patients with both HCC and cirrhosis, 22% in patients with cholangiocarcinoma, 12% in patients with non-cancer chronic liver disease and 3% of subjects in the reference group. Thus, plasma concentrations of R249S-mutated DNA ≥ 150 copies/mL tended to be more common in patients with HCC developing without pre-existing cirrhosis (p = 0.027). Overall, these results support the preferential occurrence of R249S-mutated DNA in HCC developing in the absence of cirrhosis in a context of HBV chronic infection.

Organization and evolution of organized cervical cytology screening in Thailand.

OBJECTIVE: To describe phase 1 of an organized cytology screening project initiated in Thailand by the Ministry of Public Health and the National Health Security Office. METHODS: Women aged 35-60 years were encouraged to undergo cervical screening in primary care units and hospitals through awareness programs. Papanicolaou smears were processed and reported at district or provincial cytology laboratories. Women with normal test results were advised to undergo repeat screening after 5 years, while those with precancerous and cancerous lesions were referred for colposcopy, biopsy, and treatment. Information on screening, referral, investigations, and therapy were logged in a computer database. RESULTS: Between 2005 and 2009, 69.2% of the 4030833 targeted women were screened. In all, 20991 women had inadequate smears; 27253 had low-grade squamous intraepithelial lesions; 15706 had high-grade squamous intraepithelial lesions; and 2920 had invasive cancers. Information on the management of precancerous lesions was available for only 17.4% of women referred for colposcopy. CONCLUSION: Although follow-up data on women with positive test results were inadequately documented, the present findings indicate that provision of cytology services through the existing healthcare system is feasible.

Socioeconomic impact of cancer in member countries of the Association of Southeast Asian Nations (ASEAN): the ACTION study protocol.

Cancer can be a major cause of poverty. This may be due either to the costs of treating and managing the illness as well as its impact upon people's ability to work. This is a concern that particularly affects countries that lack comprehensive social health insurance systems and other types of social safety nets. The ACTION study is a longitudinal cohort study of 10,000 hospital patients with a first time diagnosis of cancer. It aims to assess the impact of cancer on the economic circumstances of patients and their households, patients' quality of life, costs of treatment and survival. Patients will be followed throughout the first year after their cancer diagnosis, with interviews conducted at baseline (after diagnosis), three and 12 months. A cross-section of public and private hospitals as well as cancer centers across eight member countries of the Association of Southeast Asian Nations (ASEAN) will invite patients to participate. The primary outcome is incidence of financial catastrophe following treatment for cancer, defined as out-of-pocket health care expenditure at 12 months exceeding 30% of household income. Secondary outcomes include illness induced poverty, quality of life, psychological distress, economic hardship, survival and disease status. The findings can raise awareness of the extent of the cancer problem in South East Asia and its breadth in terms of its implications for households and the communities in which cancer patients live, identify priorities for further research and catalyze political action to put in place effective cancer control policies.

Evaluation of health status of a population underwent routine medical check up at the high risk screening clinic in National Cancer Institute.

The objective of the study was to evaluate the efficacy of a health check-up program among Thai people at the National Cancer Institute in the years 2008-2009. The program included history taking, physical examination, chest X-ray, EKG, and laboratory tests. A total of 28,240 women and 9,665 men were included in the study, with mean ages of 44.5 and 46.9 years, respectively. The study showed that obesity, as assessed by a BMI over 25.0 kg/m2, in men and women was present in 41.4% and 30%, respectively. Biochemical study revealed that anemia was prevalent in 21.6% of men and 20.1% of women. High plasma glucose level (>115 mg/dL), cholesterol level (>200 mg/dL), triglyceride level (>190 mg/dL) in men was 13.8%, 63.8%, 22.6% and 7.7%, 61.1%, 8.9% in women. Hepatitis B virus infection was found 7.5% in men and 4.1% in women. In this study, 177 new cancer cases were detected, of which 35 were breast, 19 were cervical and 26 were colorectal, most of these cancers being detected at early stage. In addition, precancerous states was also found including 718 cases of benign and 99 cases of adenoma in situ. In conclusion, an annual check up may detect abnormalities that have no obvious clinical symptoms of disease. Early detection of asymptomatic neoplasms and precursor lesions should contribute to a prompt provision of treatment and further decline of death from cancer.

Measuring herpes zoster, zoster-associated pain, post-herpetic neuralgia-associated loss of quality of life, and healthcare utilization and costs in Thailand.

OBJECTIVES: This study aimed to measure the herpes zoster-associated burden of illness, healthcare utilization, and costs among Thai patients. METHODS: This prospective cohort study of 180 patients aged ≥ 50 years and healthy, or ≥ 20 years and immunosuppressed, with zoster rash, was conducted in Bangkok and its environs, Thailand, during 2007-2008. Each patient was followed for six months for zoster-associated rash, pain, quality of life (QoL), and healthcare utilization and costs. RESULTS: A total of 180 subjects were enrolled in the study. Their mean ± standard deviation (SD) age was 58.9 ± 13.8 years. Of the 180 patients enrolled, 138 (76.7%), 34 (18.9%) and eight (4.4%) patients were elderly, HIV-infected, and receiving immunosuppressive agents, respectively; 35 (19.4%) had post-herpetic neuralgia (PHN), and 13 (7.2%) had zoster ophthalmicus. The severity of zoster pain was moderately highly correlated with activities of daily living (ADL), at 0.68 ≤ ρ ≤ 0.76. Most patients required only one or two outpatient visits. The mean ± SD total of direct healthcare costs was 3083.4 ± 5047.0 Thai baht or ∼ 1.1% of annual income per capita. CONCLUSIONS: Herpes zoster contributes a significant burden of illness to both patients and the wider community.

Hepatitis viruses and risk of cholangiocarcinoma in northeast Thailand.

Liver cancer is the most common cancer in males in Thailand and the third in females. A high incidence of cholangiocarcinoma (CCA) is estimated in the northeast of Thailand. Chronic infection with Opisthorchis viverrini (OV) is the major risk factor for development of CCA. It has been demonstrated that HCV infection is a risk factor for CCA in non - endemic area of OV infection. We examined the association of HBV and HCV and risk of CCA in the northeast Thailand. All cases of CCA were recruited between 1999 and 2001 from Nakhon Phanom provincial hospital and all community hospitals in the province. One control per case was selected, matched by sex, age (∓5 years) and residence. 106 case-control pairs were obtained. Anti-OV, HBsAg, and Anti HCV were determined by ELISA. Among 103 age-sex-place of residence matched case-control pairs, there were 7, 0, 0, 96 pairs for anti-HCV (+) case vs. (-) control, (+) case vs. (+) control, (-) case vs. (+) control and (-) case vs. (-) control combinations (OR=7/0). Among 106 matched pairs, there were 9, 2, 4, 91 pairs for the similar four combinations of HBsAg (OR=2.25 (95%CI: 0.63-10.0). If the subject had anti-HCV and/or HBsAg, the OR for CCA was 4.00 (95%CI: 1.29-16.4). Even after adjustment for anti-OV, risk for HBsAg and/or anti-HCV positive was still marginally increased with an OR of 4.69 although not reaching statistical significance (95%CI: 0.98-22.5). Hepatitis B and C virus infection may also play role in the development of CCA in northeast Thailand.

Case-control study of occupational categories and breast cancer risk in Thailand.

Breast cancer is common malignancy in Thai female. Although there are well established risk factors, many environmental agents with an impact are still unknown especially with reference to occupation. The objective of this study was to investigate the risk of female breast cancer among different occupational categories in Thailand. A frequency-matched case-control study was conducted among Thai women aged 17-79. A total of 516 pairs of cases and controls were recruited at the Thai National Cancer Institute, Khon Kaen University Hospital and Khon Kaen Provincial Hospital during 2002-2004. Cases were newly diagnosed with histological confirmed breast cancers while controls were selected from healthy women matched by age (± 5 years) and geographical area. After informed consent was signed, information was obtained on occupation and other risk factors from each subject using an interviewer-administered and structured questionnaire. The International Standard Classification of Occupations version 1968 (ISCO-68) was used to code for occupational categories. The relation between occupational categories and breast cancer risk was evaluated by unconditional logistic regression analysis. The mean age of cases and controls were 46.9 ± 10.6 and 47.8 ± 9.9 years, respectively. Fifty-five percent of cases were pre-menopausal women. After adjusting for confounding factors by multiple logistic regression analysis, the results showed that occupational category as production and related workers, transport equipment operators and labourers was associated with an increased risk of breast cancer (OR=1.41 95% CI=1.01-1.97) and this finding was also supported by a statistically significant positive trend for duration of employment (p=0.01). A significantly decreased breast cancer risk was observed in clerks (OR=0.59, 95% CI=0.37-0.96). In conclusion, this study revealed that women who have lifetime occupation in an industrial setting may have higher risk to develop breast cancer. Further studies are needed to assess occupational exposure in specific occupations.

Cancer epidemiology in mainland South-East Asia - past, present and future.

The countries of mainland South-East Asia, Myanmar, Thailand, Laos, Cambodia and Viet Nam, share a long history of interactions and many cultural similarities, as well as geographical contiguity. They therefore can be usefully examined as a group when considering measures for control of cancer and other non-communicable diseases. Liver cancer is consistently found at higher incidence than most other parts of Asia, with lung cancer as the other most important neoplasm in males. In females cervical and breast cancer about equally predominate, throughout. However, there are also major differences, particularly with regard to stomach and nasopharyngeal cancer, only found at relatively high incidence in Viet Nam. The present review was conducted to gather together registry data on cancer prevalence and epidemiological findings cited in PubMed in order to obtain as comprehensive picture as possible of the present status. It is hoped that future cooperation across the region will facilitate development of coordinated cancer control programs to reduce the burden.

Genetic polymorphisms in folate and alcohol metabolism and breast cancer risk: a case-control study in Thai women.

Dietary folate as well as polymorphic variants in one-carbon metabolism genes may modulate risk of breast cancer through aberrant DNA methylation and altered nucleotide synthesis and repair. Alcohol is well recognized as a risk factor for breast cancer, and interactions with one-carbon metabolism has also been suggested. The purpose of this study is to test the hypothesis that genetic polymorphisms in the folate and alcohol metabolic pathway are associated with breast cancer risk. Twenty-seven single nucleotide polymorphisms (SNPs) in the MTR, MTRR, MTHFR, TYMS, ADH1C, ALDH2, GSTP1, NAT1, NAT2, CYP2E1 DRD2, DRD3, and SLC6A4 were genotyped. Five hundred and seventy patients with histopathogically confirmed breast cancer and 497 controls were included in the present study. Association of genotypes with breast cancer risk was evaluated using multivariate logistic regression to estimate odds ratios (OR) and their 95% confidence intervals (95% CI). Increased risk was observed for homozygotes at the MTR SNPs (rs1770449 and rs1050993) with the OR = 2.21 (95% CI 1.18-4.16) and OR = 2.24 (95% CI 1.19-4.22), respectively. A stratified analysis by menopausal status indicated the association between the NAT2 SNP (rs1799930) and breast cancer was mainly evident in premenopausal women (OR 2.70, 95% CI 1.20-6.07), while the MTRR SNP (rs162049) was significant in postmenopausal women (OR 1.61, 95% CI 1.07-2.44). Furthermore, SNPs of the genes that contribute to alcohol behavior, DRD3 (rs167770), DRD2 (rs10891556), and SLC6A4 (rs140701), were also associated with an increased risk of breast cancer. No gene-gene or gene-environment interactions were observed in this study. Our results suggest that genetic polymorphisms in folate and alcohol metabolic pathway influence the risk of breast cancer in Thai population.

High urinary excretion of lipid peroxidation-derived DNA damage in patients with cancer-prone liver diseases.

Chronic inflammatory processes induce oxidative and nitrative stress that trigger lipid peroxidation (LPO), whereby DNA-reactive aldehydes such as trans-4-hydroxy-2-nonenal (HNE) are generated. Miscoding etheno-modified DNA adducts including 1,N(6)-etheno-2'-deoxyadenosine (epsilondA) are formed by reaction of HNE with DNA-bases which are excreted in urine, following elimination from tissue DNA. An ultrasensitive and specific immunoprecipitation/HPLC-fluorescence detection method was developed for quantifying epsilondA excreted in urine. Levels in urine of Thai and European liver disease-free subjects were in the range of 3-6 fmol epsilondA/micromol creatinine. Subjects with inflammatory cancer-prone liver diseases caused by viral infection or alcohol abuse excreted massively increased and highly variable epsilondA-levels. Groups of Thai subjects (N=21) with chronic hepatitis, liver cirrhosis, or hepatocellular carcinoma (HCC) due to HBV infection had 20, 73 and 39 times higher urinary epsilondA levels, respectively when compared to asymptomatic HBsAg carriers. In over two thirds of European patients (N=38) with HBV-, HCV- and alcohol-related liver disease, urinary epsilondA levels were increased 7-10-fold compared to healthy controls. Based on this pilot study we conclude: (i) high urinary epsilondA-levels, reflecting massive LPO-derived DNA damage in vivo may contribute to the development of HCC; (ii) epsilondA-measurements in urine and target tissues should thus be further explored as a putative risk marker to follow malignant progression of inflammatory liver diseases in affected patients; (iii) etheno adducts may serve as biomarkers to assess the efficacy of (chemo-)preventive and therapeutic interventions.

Genetic polymorphisms of estrogen metabolizing enzyme and breast cancer risk in Thai women.

Estrogen and its metabolites are believed to play important roles in breast cancer, and its determinants include both genetic and lifestyle factors. The objective of the study is to investigate the association of breast cancer risk in Thailand with genetic polymorphisms in several genes involved in estrogen synthesis and metabolism. Five hundred and seventy patients with histopathologically confirmed breast cancer and 497 controls were included in the present study. Forty single nucleotide polymorphisms (SNPs) in the CYP1A1, CYP1A2, CYP1B1, CYP17, CYP19, CYP2C9, CYP2C19, AhR, ESR1, PGR, ERRG, COMT, HSD17B1, HSD17B2, EPHX1 and NQO1 genes were genotyped. Association of genotypes with breast cancer risk was evaluated using multivariate logistic regression, which suggested an altered risk for the following SNPs [gene, odds ratio (OR) and 95% confidence interval are shown]: heterozygote carriers of rs4917623 [CYP2C19, OR = 1.38 (1.04-1.84)], rs2066853 [AhR, OR = 1.34 (1.02-1.76)] and rs1857407 [ERRG, (OR = 0.72 (0.55-0.96)]; homozygote carriers of rs762551 [CYP1A2, OR = 2.75 (1.47-5.14)], rs4917623 [CYP2C19, OR = 1.48 (1.00-2.19) and rs945453 [ERRG, OR = 1.66 (1.04-2.65)]. In addition, a stratified analysis by menopausal status indicated that the association of the CYP1A2 (rs762551) and CYP17 (rs743572) polymorphisms with breast cancer risk were mainly evident in premenopausal, while ERRG (rs1857407) was significant in postmenopausal women. These findings suggest that CYP1A2, CYP2C19, AhR, ERRG and CYP17 polymorphisms may play an important role in estrogen metabolism and modify individual susceptibility to breast cancer in Thai women.