Evaluation of molecular markers GSTM1 and GSTT1 and clinical factors in breast cancer: case-control study and literature review.

The study was conducted to evaluate the frequency of polymorphisms in GSTM1 and GSTT1 genes in patients with breast cancer compared with individuals without history of cancer, and the association of these polymorphisms with clinical/epidemiological parameters.There were evaluated 752 women (219 patients and 533 controls). Molecular analysis was performed by the Polymerase Chain Reaction (PCR). Statistical analysis was used multiple logistic regression and descriptive statistics.Age ≥ 50 years (OR = 3.22, 95% CI = 2.30-4.51, p < 0.001) and alcohol consumption (OR = 1.60, 95% CI = 1.13-2.27, p = 0.008) were associated to the development of breast cancer, while smoking and null genotypes GSTM1 and GSTT1 presented no association. GSTM1 and GSTT1 polymorphisms presented no relationship with the clinical and histopathological parameters or molecular subtypes of breast cancer. Ninety-two percent of tumours were invasive ductal, 66% were grade II, 65% were larger than 2 cm, the stages II (35.3%) and III (31.2%) were the most prevalent, and 47.7% were molecular subtype luminal B.Individuals aged ≥ 50 years and alcohol consumers have more chance to developing breast cancer. GSTM1 and GSTT1 polymorphisms are not associated to the risk of breast cancer.

Polymorphisms in xenobiotic metabolism-related genes in patients with hepatocellular carcinoma: a case-control study.

This study was performed to investigate the relationship between polymorphisms in microsomal epoxide hydrolase (mEH; Tyr113His and His139Arg substitution) and glutathione S-transferase (GST; GSTM1 deletion, GSTT1 deletion, and GSTP1.Ala114Val substitution) and their correlation with clinico-histopathological features in hepatocellular carcinoma (HCC).We evaluated environmental risk factors and genetic alterations in 556 individuals (86 cases and 470 controls). PCR multiplex for GSTM1 and GSTT1, polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) for GSTP1, and real-time PCR for mEH were performed. Statistical analyses were performed using multiple logistic regression tests.Age over 48 years (p < 0.001) and alcohol consumption (p = 0.021) were the predictors of increased risk of developing HCC. GSTP1.Ala114Val for all regression models (p < 0.05), except the recessive model, and the GSTT1 null genotype (odds ratio [OR] = 0.43, 95% confidence interval [CI] = 0.21-0.87, p = 0.019) were predictors of an increased risk of developing HCC. Polymorphic GSTT1, GSTM1, GSTP1.Ala114Val, and mEH.His139Arg and wild-type mEH.Tyr113His (OR = 5.04; 95% CI = 1.59-16.04; p = 0.006) were associated with HCC.Age over 48 years, alcohol consumption, and the presence of polymorphic variants of GSTP1 and GSTT1 were associated with the risk of developing HCC.

Association between GSTP1, GSTM1 and GSTT1 polymorphisms involved in xenobiotic metabolism and head and neck cancer development.

Polymorphisms in the glutathione S-transferase superfamily genes that encodes enzymes involved in the phase II xenobiotic metabolism may lead head and neck cancer development. In this study we investigate the association of A313G and C341T GSTP1 polymorphisms, GSTM1 and GSTT1 null genotypes in the head and neck cancer development, interactions between these polymorphisms,the tumor histopathologic parameters and risk factors (smoking and drinking) were also evaluated in the case-control study. 775 individuals (261 patients/514 controls) were included in the study. Molecular analyzes were performed by PCR and PCR-RFLP; and statistical analyzes by Chi square and multiple logistic regression. Chi square test showed that only the genotype frequencies for GSTM1 and GSTT1 were in Hardy-Weinberg disequilibrium in both groups. Significant results with p ≤ 0.05 showed that age ≥ 48 years (OR = 11.87; 7.55-18.65), smoking (OR = 4.25; 2.70-6.69), drinking (OR = 1.59; 1.02-2.46) were possible predictors for the head and neck cancer development and the presence of A313G GSTP1 polymorphism (OR = 0.62; 0.42-0.92) decreased the risk for this disease. Individuals with the 313AG/GG GSTP1 and age ≥ 48 years (OR = 0.59; 0.38-0.91), male gender (OR = 0.54; 0.35-0.83), smokers (OR = 0.63; 0.40-0.99) and drinkers (OR = 0.57; 0.35-0.95); the GSTM1 null genotype and age < 48 years (OR = 2.46; 1.09-5.55); the GSTT1 null genotype and primary anatomical sites of pharynx (OR = 0.37; 0.17-0.79) and larynx (OR = 3.60; 1.93-6.72), can modulate the risk for the disease development. The variables age ≥ 48 years, smoking and drinking can be predictors for head and neck cancer development; moreover, A313G GSTP1 polymorphism, GSTM1 and GSTT1 null genotypes can modulate the risk for this disease.

Polymorphisms of the CYP1A1 and CYP2E1 genes in head and neck squamous cell carcinoma risk.

Polymorphisms in genes that encode P450 cytochrome enzymes may increase carcinogen activation or decrease their inactivation and consequently, promote the development of cancer. The aims of this study were to identify the MspI-CYP1A1, PstI-CYP2E1 and DraI-CYP2E1 polymorphisms in patients with head and neck cancer and to compare with individuals without cancer; to evaluate the association of these polymorphisms with risk factors and clinical histopathological parameters. In the study group, 313 patients were evaluated for CYP1A1, 217 for CYP2E1 (PstI) and 211 for CYP2E1 (DraI) and in the control group 417, 334 and 374 individuals, respectively. Molecular analysis was performed by PCR-RFLP technique, and chi-square and multiple logistic regression tests were used for statistical analysis. The result of analysis regarding individuals evaluated for CYP1A1 (MspI) showed that age (OR: 8.15; 95% CI 5.57-11.92) and smoking (OR: 5.37; 95% CI 3.52-8.21) were predictors for the disease; for the CYP2E1 (PstI and DraI), there were associations with age (PstI-OR: 9.10; 95% CI 5.86-14.14/DraI-OR: 8.07; 95% CI 5.12-12.72), smoking (PstI-OR: 4.10; 95% CI 2.44-6.89/DraI-OR: 5.73; 95% CI 3.34-9.82), alcohol (PstI-OR: 1.93; 95% CI 1.18-3.16/DraI-OR: 1.69; 95% CI 1.02-2.81), respectively, with disease development. CYP2E1 (PstI) was less frequent in patient group (OR: 0.48; 95% CI 0.23-0.98). Regarding clinical histopathological parameters, CYP1A1 polymorphism was less frequent in the larynx primary anatomic site (OR = 0.45; 95% CI = 0.28-0.73; P = 0.014). In conclusion, we confirm that age, smoking and alcohol consumption are risk factors for this disease and the polymorphisms investigated have no association with the development of head and neck cancer.

Glutathione S-transferase Polymorphisms in Head and Neck Squamous Cell Carcinoma Treated with Chemotherapy and/or Radiotherapy.

BACKGROUND/AIM: The Glutathione S-transferases (GSTs) are important carcinogen-metabolizing enzymes. Polymorphisms involved in these enzymes can modulate the development and treatment of head and neck cancer. To investigate the association of GSTs polymorphisms with head and neck cancer and risk factors, clinical-pathological features, and survival time of the patients treated with chemotherapy and/or radiotherapy. METHODS: The GST gene polymorphisms were evaluated in 197 cases and 514 controls by PCR-RFLP-Polymerase Chain Reaction Restriction Fragment Length Polymorphism. RESULTS: The GSTP-313 was associated with a decreased risk for HNSCC (p=0.050). The GSTP1 haplotype analysis revealed a higher frequency of the AC and AT haplotypes in the case group than in the control group (p=0.013 and p=0.019, respectively), and the opposite for G-C haplotype (p = 0.015). Yet, the different combinations between the genotypes were associated with an increased risk of cancer. The study showed no association between the polymorphisms and primary tumor site, clinical-pathological characteristics, treatment (chemotherapy and/or radiotherapy) and survival time of the patients. CONCLUSION: The GST polymorphisms combination showed an increased risk for carcinogenesis, and studies with larger casuistry can contribute to the clarification of the role in individual patient differences for the response to chemotherapy and/or radiotherapy and identify biomarkers of susceptibility.

Molecular evaluation of glutathione S transferase family genes in patients with sporadic colorectal cancer.

AIM: To evaluate the association between polymorphisms in glutathione S transferases (GSTs) and the risk of sporadic colorectal cancer (SCRC), tumor progression and the survival of patients. METHODS: A case-control study of 970 individuals from the Brazilian population was conducted (232 individuals from the case group with colorectal cancer and 738 individuals from the control group without a history of cancer). PCR multiplex and PCR-RFLP techniques were used to genotype the GST polymorphisms. The tumors were categorized according to the TNM classification: tumor extension (T), affected lymph nodes (N), and presence of metastasis (M). Logistic regression, multiple logistic regression and survival analysis were used to analyze the data. The results are presented in terms of odds ratio (OR) and 95% confidence interval (CI). The level of significance was set at 5% (P ≤ 0.05). RESULTS: Age equal to or over 62 years (OR = 8.79; 95%CI: 5.90-13.09, P < 0.01) and female gender (OR = 2.91; 95%CI: 1.74-4.37; P < 0.01) were associated with increased risk of SCRC. Analysis of the polymorphisms revealed an association between the GSTM1 polymorphisms and a risk of SCRC (OR = 1.45; 95%CI: 1.06-2.00; P = 0.02), as well as between GSTT1 and a reduced risk of the disease (OR = 0.65; 95%CI: 0.43-0.98; P = 0.04). An interaction between the presence of the wild-type allele of GSTP1 Ile105Val polymorphism and tobacco consumption on risk of SCRC (OR = 2.33; 95%CI: 1.34-4.05; P = 0.05) was observed. There was an association between the GSTM1 null genotype and the presence of advanced tumors (OR = 2.33; 95%CI: 1.23-4.41; P = 0.009), as well as increased risk of SCRC in the presence of a combination of GSTT1 non-null/GSTM1 null genotypes (OR = 1.50; 95%CI: 1.03-2.19; P = 0.03) and GSTT1 non-null/GSTM1 null/GSTP1 Val* (OR = 1.85; 95%CI: 1.01-3.36, P = 0.04). Combined GSTT1 non-null/GSTM1 null genotypes (OR = 2.40; 95%CI: 1.19-4.85; P = 0.01) and GSTT1 non-null/GSTM1 null/GSTP1 Val* (OR = 2.92; 95%CI: 1.05-8.12; P = 0.04) were associated with tumor progression. Polymorphisms were not associated with the survival of patients with SCRC. CONCLUSION: Females aged 62 years or older are more susceptible to SCRC. Polymorphisms of GSTT1 and GSTM1 null genotypes modulated the susceptibility to SCRC in the population studied.

Differential Expression of Prostaglandin I2 Synthase Associated with Arachidonic Acid Pathway in the Oral Squamous Cell Carcinoma.

INTRODUCTION: Differential expression of genes encoding cytochrome P450 (CYP) and other oxygenases enzymes involved in biotransformation mechanisms of endogenous and exogenous compounds can lead to oral tumor development. OBJECTIVE: We aimed to identify the expression profile of these genes, searching for susceptibility biomarkers in oral squamous cell carcinoma. PATIENTS AND METHODS: Sixteen oral squamous cell carcinoma samples were included in this study (eight tumor and eight adjacent non-tumor tissues). Gene expression quantification was performed using TaqMan Array Human CYP450 and other Oxygenases 96-well plate (Applied Biosystems) by real time qPCR. Protein quantification was performed by ELISA and IHC methods. Bioinformatics tools were used to find metabolic pathways related to the enzymes encoded by differentially expressed genes. Results. CYP27B1, CYP27A1, CYP2E1, CYP2R1, CYP2J2, CYP2U1, CYP4F12, CYP4X1, CYP4B1, PTGIS, ALOX12, and MAOB genes presented differential expression in the oral tumors. After correction by multiple tests, only the PTGIS (Prostaglandin I2 Synthase) gene presented significant differential expression (P < 0.05). The PTGIS gene and protein were reduced in oral tumors. CONCLUSION: PTGIS presents downexpression in oral tumors. PTGIS play an important role in the arachidonic acid metabolism. Arachidonic acid and/or metabolites are derived from this pathway, which can influence the regulation of important physiological mechanisms in tumorigenesis process.

CYP1A1, CYP2E1 and EPHX1 polymorphisms in sporadic colorectal neoplasms.

AIM: To investigate the contribution of polymorphisms in the CYP1A1, CYP2E1 and EPHX1 genes on sporadic colorectal cancer (SCRC) risk. METHODS: Six hundred forty-one individuals (227 patients with SCRC and 400 controls) were enrolled in the study. The variables analyzed were age, gender, tobacco and alcohol consumption, and clinical and histopathological tumor parameters. The CYP1A1*2A, CYP1A1*2C CYP2E1*5B and CYP2E1*6 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The EPHX1 Tyr113His, EPHX1 His139Arg and CYP1A1*2C polymorphisms were detected by real-time PCR. Chi-squared test and binary logistic regression were used in the statistical analysis. Haplotype analysis was conducted using the Haploview program, version 2.05. RESULTS: Age over 62 years was a risk factor for SCRC development (OR = 7.54, 95%CI: 4.94-11.50, P < 0.01). Male individuals were less susceptible to SCRC (OR = 0.55, 95%CI: 0.35-0.85, P < 0.01). The CYP2E1*5B polymorphism was associated with SCRC in the codominant (heterozygous genotype: OR = 2.66, 95%CI: 1.64-4.32, P < 0.01), dominant (OR = 2.82, 95%CI: 1.74-4.55, P < 0.01), overdominant (OR = 2.58, 95%CI: 1.59-4.19, P < 0.01), and log-additive models (OR = 2.84, 95%CI: 1.78-4.52, P < 0.01). The CYP2E1*6 polymorphism was associated with an increased SCRC risk in codominant (heterozygous genotype: OR = 2.81, 95%CI: 1.84-4.28, P < 0.01; homozygous polymorphic: OR = 7.32, 95%CI: 1.85-28.96, P < 0.01), dominant (OR = 2.97, 95%CI: 1.97-4.50, P < 0.01), recessive (OR = 5.26, 95%CI: 1.35-20.50, P = 0.016), overdominant (OR = 2.64, 95%CI: 1.74-4.01, P < 0.01), and log-additive models (OR = 2.78, 95%CI: 1.91-4.06, P < 0.01). The haplotype formed by the minor alleles of the CYP2E1*5B (C) and CYP2E1*6 (A) polymorphisms was associated with SCRC (P = 0.002). However, the CYP1A1*2A, CYP1A1*2C, EPHX1 Tyr113His and EPHX1 His139Arg polymorphisms were not associated with SCRC. CONCLUSION: In conclusion, the results demonstrated that CYP2E1*5B and CYP2E1*6 minor alleles play a role in the development of SCRC.

Clinical and epidemiological characteristics of patients in the head and neck surgery department of a university hospital.

CONTEXT AND OBJECTIVES: Head and neck cancer is the fifth most common type of cancer worldwide. The objective of this study was to evaluate the clinical and epidemiological parameters in a head and neck surgery service. DESIGN AND SETTING: Cross-sectional study using patients' records, developed in otolaryngology and head and neck department of a university hospital in the northwest of the state of São Paulo. METHODS: A total of 995 patients in the head and neck surgery service between January 2000 and May 2010 were evaluated. The variables analyzed included: age, gender, skin color, tobacco and alcohol consumption, primary site, staging and histological tumor type, treatment and number of deaths. RESULTS: The disease was more frequent among men (79.70%), smokers (75.15%) and alcohol abusers (58.25%). The most representative sites were oral cavity (29.65%) and larynx (24.12%) for the primary site; squamous cell carcinoma (84.92%) was the most frequent histological type, and surgery (29.04%) and radiotherapy (14.19%) were the most common treatments. CONCLUSION: The cancer that affects patients assisted by the head and neck surgery service occurs mainly men, smokers and alcohol abusers, and the oral cavity and larynx are the sites with the highest incidence. The high rate of patients with stages III and IV indicates late diagnosis by the treatment centers, which reflects the need for prevention education campaigns for early diagnosis of the disease.

Clinical and epidemiological characteristics of patients in the head and neck surgery department of a university hospital / Características clínicas e epidemiológicas de pacientes do departamento de cirurgia de cabeça e pescoço em um hospital universitário

CONTEXT AND OBJECTIVES: Head and neck cancer is the fifth most common type of cancer worldwide. The objective of this study was to evaluate the clinical and epidemiological parameters in a head and neck surgery service. DESIGN AND SETTING: Cross-sectional study using patients' records, developed in otolaryngology and head and neck department of a university hospital in the northwest of the state of São Paulo. METHODS: A total of 995 patients in the head and neck surgery service between January 2000 and May 2010 were evaluated. The variables analyzed included: age, gender, skin color, tobacco and alcohol consumption, primary site, staging and histological tumor type, treatment and number of deaths. RESULTS: The disease was more frequent among men (79.70%), smokers (75.15%) and alcohol abusers (58.25%). The most representative sites were oral cavity (29.65%) and larynx (24.12%) for the primary site; squamous cell carcinoma (84.92%) was the most frequent histological type, and surgery (29.04%) and radiotherapy (14.19%) were the most common treatments. CONCLUSION: The cancer that affects patients assisted by the head and neck surgery service occurs mainly men, smokers and alcohol abusers, and the oral cavity and larynx are the sites with the highest incidence. The high rate of patients with stages III and IV indicates late diagnosis by the treatment centers, which reflects the need for prevention education campaigns for early diagnosis of the disease.

CONTEXTO E OBJETIVOS: O câncer de cabeça e pescoço é o quinto tipo mais comum entre todas as neoplasias no mundo. O objetivo do estudo foi avaliar os parâmetros clínicos e epidemiológicos em um serviço de cirurgia de cabeça e pescoço. TIPO DE ESTUDO E LOCAL: Estudo transversal com coleta de dados de prontuários, realizado no departamento de otorrinolaringologia e cabeça e pescoço de um hospital universitário do noroeste do estado de São Paulo. MÉTODOS: Um total de 995 pacientes do serviço de cirurgia de cabeça e pescoço foi avaliado entre janeiro de 2000 a maio de 2010. As variáveis analisadas foram: idade, gênero, cor da pele, consumo de álcool e tabaco, sítio primário, estádio e tipo histológico do tumor, tratamento e número de mortes. RESULTADOS: A doença foi mais frequente entre homens (79,70%), tabagistas (75,15%) e etilistas (58,25%). Os locais mais representativos foram: cavidade oral (29,65%) e laringe (24,12%) para sítio primário; carcinoma espinocelular (84,92%) foi o tipo histológico mais frequente e cirurgia (29,04%) e radioterapia (14,19%) foram os tratamentos mais comuns. CONCLUSÃO: O câncer que afeta os pacientes assistidos pelo serviço de cirurgia de cabeça e pescoço ocorre, em sua maioria, entre homens, tabagistas e etilistas, tendo a cavidade oral e a laringe maior incidência. A alta taxa de pacientes com estádios III e IV indica diagnóstico tardio pelos centros de tratamento, o que reflete a necessidade de campanhas de prevenção para o diagnóstico precoce da doença.