Epidemiology and survival outcomes of lip, oral cavity, and oropharyngeal squamous cell carcinoma in a southeast Brazilian population.

BACKGROUND: Lip, oral cavity, and oropharyngeal squamous cell carcinoma (SCC) represent a major health problem in the global scenario. In South America, the highest incidence rates are seen in Brazil. Therefore, the epidemiological and clinical profile and survival outcomes of lip, oral cavity, and oropharyngeal SCC was studied in São Paulo State, Brazil. MATERIAL AND METHODS: The clinicopathological data of 12,099 patients with lip, oral cavity, and oropharyngeal SCC were obtained from hospital cancer registries of the Fundação Oncocentro de São Paulo, Brazil (2010-2015). Survival rates and other analyses were performed using SPSS software. RESULTS: A clear male predominance was observed, particularly for patients with oropharyngeal SCC (88.3%). The average age of patients was higher for lip cases (65 ± 13.5 years) compared to other sites. The schooling level was low for most patients, especially in lip cases (87.9%). Most of the patients with oral cavity (71.8%) and oropharyngeal (86.3%) SCC had advanced-stage (III-IV) disease. However, the majority of lip cases (83.3%) were at an early stage (I-II). Surgical excision was the main treatment for lip (72%) and oral cavity SCC (23.5%), and chemoradiotherapy was the main treatment for oropharyngeal SCC (40.2%). The 5-year overall survival (OS) for patients with lip, oral cavity, and oropharyngeal SCC were 66.3, 30.9, and 22.6%, respectively. Multivariate analysis revealed that the determinants of OS were different for lip, oral cavity, and oropharyngeal SCC, except for those at the clinical stage, which was an independent predictor for all sites. CONCLUSIONS: OS-independent determinants varied according to the affected site. Oral cavity and oropharyngeal SCC presented worse survival rates than those for lip SCC.

CASE-REPORT Association between an ACAN gene variable number tandem repeat polymorphism and lumbar disc herniation: a case control study.

We investigated the association between an aggrecan gene (ACAN) polymorphism and lumbar disc herniation (LDH). This was a case-control study with quinquennial age and gender groups. The study comprised 119 men and women aged between 20 and 60 from Goiânia (Brazil). Of these, 39 were allocated to the case group (Ca) and 80 to the control group (Ct). We gathered sociodemographic and clinical data, and peripheral blood samples. DNA was isolated for genotyping the ACAN variable number tandem repeat (VNTR) via conventional polymerase chain reaction (PCR). Data were statistically analyzed using the chi-square test, multiple comparison analysis, the Student t-test, and odds ratios, with a level of significance set at 5% (P ≤ 0.05). The groups were homogenous in terms of sociodemographic, anthropometric, and life style variables. The allele score for the ACAN VNTR was significantly lower in volunteers with LDH; the A22 allele was significantly more prevalent in this same group; the Ca group presented greater frequency of short alleles A13-A25, whereas the Ct group presented a higher frequency of long alleles. However, this difference was not statistically significant. In both groups, the most common alleles were A28, A27, and A29, and the A26/A26 genotype was significantly more common in the Ca group. The results showed an association between short alleles and LDH among the investigated adults (Ca), corroborating the hypothesis that aggrecan with shorter repeat lengths can lead to a reduction in the physiological proteoglycan function of intervertebral disc hydration and, consequently, increased individual susceptibility to LDH.

The role of oral hygiene in head and neck cancer: results from International Head and Neck Cancer Epidemiology (INHANCE) consortium.

BACKGROUND: Poor oral hygiene has been proposed to contribute to head and neck cancer (HNC) risk, although causality and independency of some indicators are uncertain. This study investigates the relationship of five oral hygiene indicators with incident HNCs. METHODS: In a pooled analysis of 8925 HNC cases and 12 527 controls from 13 studies participating in the International Head and Neck Cancer Epidemiology Consortium, comparable data on good oral hygiene indicators were harmonized. These included: no denture wear, no gum disease (or bleeding), <5 missing teeth, tooth brushing at least daily, and visiting a dentist ≥once a year. Logistic regression was used to estimate the effects of each oral hygiene indicator and cumulative score on HNC risk, adjusting for tobacco smoking and alcohol consumption. RESULTS: Inverse associations with any HNC, in the hypothesized direction, were observed for <5 missing teeth [odds ratio (OR) = 0.78; 95% confidence interval (CI) 0.74, 0.82], annual dentist visit (OR = 0.82; 95% CI 0.78, 0.87), daily tooth brushing (OR = 0.83, 95% CI 0.79, 0.88), and no gum disease (OR = 0.94; 95% CI 0.89, 0.99), and no association was observed for wearing dentures. These associations were relatively consistent across specific cancer sites, especially for tooth brushing and dentist visits. The population attributable fraction for ≤ 2 out of 5 good oral hygiene indicators was 8.9% (95% CI 3.3%, 14%) for oral cavity cancer. CONCLUSION: Good oral hygiene, as characterized by few missing teeth, annual dentist visits, and daily tooth brushing, may modestly reduce the risk of HNC.

What is the future burden of HPV-related cancers in Spain?

PURPOSE: The aim of this study is to analyze mortality trends of HPV-related cancers in Spain by gender, during the period 1996-2010, and make predictions until the year 2025. METHODS: All deaths registered as cervical cancer were registered (ICD-10 code: C53), as well as vulvar and vaginal (C51 and C52), anal (C21), penile (C60), and oropharyngeal (C02, C09, C10). Adjusted rate calculations for each year were used to study the trends through the regression program Joinpoint. Predictions were made using the Nordpred program, utilizing the age-period-cohort model. RESULTS: In men, a statistically significant increase was observed in mortality by anal cancer, a reduction was observed in oropharyngeal cancer mortality and penile cancer rates were stable. In women, a statistically significant decreasing trend was observed for cervical, vulvar and vaginal cancers. In the predictions, the annual change relative to risk or population changes (size and structure) revealed a reduction in death risk by oropharyngeal cancer in men, and a reduction in death risk by anal cancer in women, although stable adjusted rates were verified for anal cancer in women. CONCLUSIONS: Although an increase was identified in the number of deaths for both genders, rates indicate gender differences in the trends, with increased rates for anal cancer and reduced rates for oropharyngeal cancer in men. Women presented reduced rates for cervical, vulvar, and vaginal cancers. For penile cancer and anal cancer in women, stable trends were verified.

Cervical cancer screening among Michigan women: 'The Special Cancer Behavioral Risk Factor Survey', 2004-2008.

The burden of cervical cancer remains greater among minority women. The purpose of this study was to evaluate racial/ethnic disparities in cervical cancer screening among minority women in Michigan. Data from 8,023 women (≥ 40 years) surveyed in the 2004-2008 Michigan Special Cancer Behavioral Risk Factor Survey were used to assess racial/ethnic differences in cervical cancer screening, knowledge and beliefs. Unexpectedly, African-American and Hispanic women reported being screened for cervical cancer at rates similar to, or higher than, Whites. Women demonstrated limited knowledge of cervical cancer risk factors and its signs/symptoms. Most minority women were more likely than Whites to believe in the importance of cervical screening, with Hispanic women more likely to support HPV vaccination. Differential utilisation of screening does not explain the disproportionately high rates of cervical cancer among minorities. Future research should examine disparities in the follow-up of abnormal cervical results and receipt of treatment.

Diabetes and breast cancer risk: a meta-analysis.

BACKGROUND: The potential of an increased risk of breast cancer in women with diabetes has been the subject of a great deal of recent research. METHODS: A meta-analysis was undertaken using a random effects model to investigate the association between diabetes and breast cancer risk. RESULTS: Thirty-nine independent risk estimates were available from observational epidemiological studies. The summary relative risk (SRR) for breast cancer in women with diabetes was 1.27 (95% confidence interval (CI), 1.16-1.39) with no evidence of publication bias. Prospective studies showed a lower risk (SRR 1.23 (95% CI, 1.12-1.35)) than retrospective studies (SRR 1.36 (95% CI, 1.13-1.63)). Type 1 diabetes, or diabetes in pre-menopausal women, were not associated with risk of breast cancer (SRR 1.00 (95% CI, 0.74-1.35) and SRR 0.86 (95% CI, 0.66-1.12), respectively). Studies adjusting for body mass index (BMI) showed lower estimates (SRR 1.16 (95% CI, 1.08-1.24)) as compared with those studies that were not adjusted for BMI (SRR 1.33 (95% CI, 1.18-1.51)). CONCLUSION: The risk of breast cancer in women with type 2 diabetes is increased by 27%, a figure that decreased to 16% after adjustment for BMI. No increased risk was seen for women at pre-menopausal ages or with type 1 diabetes.

Education, tobacco smoking, alcohol consumption, and IL-2 and IL-6 gene polymorphisms in the survival of head and neck cancer

The association of education, tobacco smoking, alcohol consumption, and interleukin-2 (IL-2 +114 and -384) and -6 (IL-6 -174) DNA polymorphisms with head and neck squamous cell carcinoma (HNSCC) was investigated in a cohort study of 445 subjects. IL-2 and IL-6 genotypes were determined by real-time PCR. Cox regression was used to estimate hazard ratios (HR) and 95 percent confidence intervals (95 percentCI) of disease-specific survival according to anatomical sites of the head and neck. Mean age was 56 years and most patients were males (87.6 percent). Subjects with 5 or more years of schooling had better survival in larynx cancer. Smoking had no effect on HNSCC survival, but alcohol consumption had a statistically significant effect on larynx cancer. IL-2 gene +114 G/T (HR = 0.52; 95 percentCI = 0.15-1.81) and T/T (HR = 0.22; 95 percentCI = 0.02-3.19) genotypes were associated with better survival in hypopharynx cancer. IL-2 +114 G/T was a predictor of poor survival in oral cavity/oropharynx cancer and larynx cancer (HR = 1.32; 95 percentCI = 0.61-2.85). IL-2 -384 G/T was associated with better survival in oral cavity/oropharynx cancer (HR = 0.80; 95 percentCI = 0.45-1.42) and hypopharynx cancer (HR = 0.68; 95 percentCI = 0.21-2.20), but an inverse relationship was observed for larynx cancer. IL-6 -174 G/C was associated with better survival in hypopharynx cancer (HR = 0.68; 95 percentCI = 0.26-1.78) and larynx cancer (HR = 0.93; 95 percentCI = 0.42-2.07), and C/C reduced mortality in larynx cancer. In general, our results are similar to previous reports on the value of education, smoking, alcohol consumption, and IL-2 and IL-6 genetic polymorphisms for the prognosis of HNSCC, but the risks due to these variables are small and estimates imprecise.

Education, tobacco smoking, alcohol consumption, and IL-2 and IL-6 gene polymorphisms in the survival of head and neck cancer.

The association of education, tobacco smoking, alcohol consumption, and interleukin-2 (IL-2 +114 and -384) and -6 (IL-6 -174) DNA polymorphisms with head and neck squamous cell carcinoma (HNSCC) was investigated in a cohort study of 445 subjects. IL-2 and IL-6 genotypes were determined by real-time PCR. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) of disease-specific survival according to anatomical sites of the head and neck. Mean age was 56 years and most patients were males (87.6%). Subjects with 5 or more years of schooling had better survival in larynx cancer. Smoking had no effect on HNSCC survival, but alcohol consumption had a statistically significant effect on larynx cancer. IL-2 gene +114 G/T (HR = 0.52; 95%CI = 0.15-1.81) and T/T (HR = 0.22; 95%CI = 0.02-3.19) genotypes were associated with better survival in hypopharynx cancer. IL-2 +114 G/T was a predictor of poor survival in oral cavity/oropharynx cancer and larynx cancer (HR = 1.32; 95%CI = 0.61-2.85). IL-2 -384 G/T was associated with better survival in oral cavity/oropharynx cancer (HR = 0.80; 95%CI = 0.45-1.42) and hypopharynx cancer (HR = 0.68; 95%CI = 0.21-2.20), but an inverse relationship was observed for larynx cancer. IL-6 -174 G/C was associated with better survival in hypopharynx cancer (HR = 0.68; 95%CI = 0.26-1.78) and larynx cancer (HR = 0.93; 95%CI = 0.42-2.07), and C/C reduced mortality in larynx cancer. In general, our results are similar to previous reports on the value of education, smoking, alcohol consumption, and IL-2 and IL-6 genetic polymorphisms for the prognosis of HNSCC, but the risks due to these variables are small and estimates imprecise.

Alcohol and tobacco, and the risk of cancers of the upper aerodigestive tract in Latin America: a case-control study.

BACKGROUND: Cancers of the upper aerodigestive tract (UADT; including oral cavity, pharynx, larynx and oesophagus) have high incidence rates all over the world, and they are especially frequent in some parts of Latin America. However, the data on the role of the major risk factors in these areas are still limited. METHODS: We have evaluated the role of alcohol and tobacco consumption, based on 2,252 upper aerodigestive squamous-cell carcinoma cases and 1,707 controls from seven centres in Brazil, Argentina, and Cuba. RESULTS: We show that alcohol drinkers have a risk of UADT cancers that is up to five times higher than that of never-drinkers. A very strong effect of aperitifs and spirits as compared to other alcohol types was observed, with the ORs reaching 12.76 (CI 5.37-30.32) for oesophagus. Tobacco smokers were up to six times more likely to develop aerodigestive cancers than never-smokers, with the ORs reaching 11.14 (7.72-16.08) among current smokers for hypopharynx and larynx cancer. There was a trend for a decrease in risk after quitting alcohol drinking or tobacco smoking for all sites. The interactive effect of alcohol and tobacco was more than multiplicative. In this study, 65% of all UADT cases were attributable to a combined effect of alcohol and tobacco use. CONCLUSIONS: In this largest study on UADT cancer in Latin America, we have shown for the first time that a prevailing majority of UADT cancer cases is due to a combined effect of alcohol and tobacco use and could be prevented by quitting the use of either of these two agents.

Involvement of CYP1A1, GST, 72TP53 polymorphisms in the pathogenesis of thyroid nodules.

Specific genotypes appear to be related to the development of thyroid disease. We examined whether polymorphisms of the genes CYP1A1, GSTM1, GSTT1, and TP53 at codon 72 are associated with increased risk for thyroid nodules. Blood samples were obtained from 122 thyroid patients with nodules and from 134 healthy control individuals from Goiânia city, GO, Brazil. We found no significant association of CYP1A1m1 and CYP1A1m2 genotypes with thyroid diseases (P > 0.05). The null genotypes of GSTM1 and GSTT1 genes were predominant in patients with nodules, indicating that individuals that possess these genotypes have a predisposition for thyroid disease. The genotype p53Arg Arg was associated with a low risk for thyroid cancer (OR = 0.15; P < 0.0001), indicating that the arginine allele in homozygosis could have a protective effect against carcinogenesis. On the other hand, the p53ArgPro genotype was significantly associated with malignant neoplastic nodules (OR = 3.65; P = 0.001). Interindividual variation in susceptibility to thyroid diseases could provide new perspectives for early diagnosis, prognosis and treatment, indicating which patients with thyroid nodules will benefit from treatment, depending on specific polymorphic profiles.

TP53 and EGFR mutations in combination with lifestyle risk factors in tumours of the upper aerodigestive tract from South America.

Cancers of the upper aerodigestive tract [(UADT): oral cavity, pharynx, larynx and oesophagus] have high incidence rates in some parts of South America. Alterations in the TP53 gene are common in these cancers. In our study, we have estimated the prevalence and patterns of TP53 mutations (exons 4-10) in 236 UADT tumours from South America in relation to lifestyle risk factors, such as tobacco smoking and alcohol drinking. Moreover, we have conducted a pilot study of EGFR mutations (exons 18-21) in 45 tumours from the same population. TP53 mutation prevalence was high: 59% of tumours were found to carry mutant TP53. We found an association between TP53 mutations and tobacco smoking and alcohol drinking. The mutation rate increased from 38% in never-smokers to 66% in current smokers (P-value for trend = 0.09). G:C>T:A transversions were found only in smokers (15%). Alcohol drinkers carried more G:C>A:T transitions (P = 0.08). Non-exposed individuals were more probable to carry G:C>A:T transitions at CpG sites (P = 0.01 for never-smokers and P < 0.001 for never-drinkers). EGFR mutations were found in 4% of cases. Inactivation of TP53 by mutations is a crucial molecular event in the UADT carcinogenesis and it is closely related to exposure to lifestyle risk factors. EGFR mutations do not appear to be a common event in UADT carcinogenesis in this population.

Childhood leukaemias and lymphomas in Greece (1996-2006): a nationwide registration study.

BACKGROUND: Monitoring time trends in the incidence of childhood leukaemias and lymphomas requires efficient and continuous data collecting systems. In countries without official cancer registries, such as Greece, ad hoc nationwide registration of incident childhood leukaemias and lymphomas could help elucidate the underlying aetiology and monitor socioeconomic differentials in health care delivery. METHODS: We registered all cases and produced age, gender, type and immunophenotype specific figures and overall crude and age adjusted annual incidence rates and secular trends for 863 leukaemia and 311 lymphoma incident cases diagnosed in children <15 years of age across Greece during 1996-2006, namely the first 11 years of the Nationwide Registry for Childhood Hematological Malignancies. RESULTS: The epidemiological profiles of leukaemias/lymphomas in Greece are similar to those in industrialised countries. No secular trends are observed for either malignancy during the studied period. However, the calculated incidence for leukaemia (46.60 cases per 1 million children annually) is among the highest in the EU-27 (19% higher than average; p<0.001), whereas that for lymphoma (16.8 cases per 1 million children annually) is around the EU-27 average. CONCLUSIONS: Minimal secular changes in childhood leukaemias/lymphomas have been noted recently in the EU-27, which cannot be easily explained in countries with small populations. Therefore, centralised EU databases such as the Automated Childhood Cancer Information System (ACCIS) should be enlarged to generate sufficient statistical power for monitoring time trends. It would be interesting to explore whether different lifestyle patterns across the EU might be responsible for the observed excess leukaemia incidence in countries such as Greece.

Detecção fo genoma de HPV em pacientes com carcinoma espino-celular da laringe: comparação entre os ensaios de PCR convencional e em tempo real / Detection of HPV genome in patients with squamous cell carcinoma of the larynx: comparison between conventional and real time PCR assays

A interação do genoma do HPV com o genoma da célula hospedeira ou de proteínas virais com proteínas celulares necessárias ao controle do ciclo celular desencadeia a morte celular ou age como fator de iniciação e progressão de processos malignos. Diversostrabalhos têm sido desenvolvidos no sentido de associar a infecção de HPV aos cânceres de cabeça e pescoço. O objetivo do presente estudo foi comparar a detecção do genoma de HPV em pacientes com CEC da laringe, considerando os ensaios de PCR convencional e em tempo real. O grupo amostral foi constituído de 15 pacientes do Registro de Câncer de Base Populacional da ACCG. Das peças cirúrgicas, foi obtido DNA total, usado na investigação molecular, para detecção do genoma de HPV, utilizando os primers genéricos GP05/06, que detectam todos os tipos de HPV. O genoma de HPV foi amplificado em 30 dos casos por PCR convencional e no ensaio de PCR em tempo real apresentaram amplificação em 46,7 das amostras, evidenciando uma diferença em 40 . Os estudosde associação entre o HPV e os cânceres da laringe são importantes no sentido de ampliar o conhecimento acerca dos mecanismos de infecção, iniciação e promoção tumoral potencializada por estes vírus.

Avaliação da qualidade de vida de pessoas portadoras de câncer de cabeça e pescoço / Assessment of quality of live in head and neck cancer patients

Este estudo propõe-se a uma breve revisão da literatura sobre qualidade de vida (QV) e câncer de cabeça e pescoço, bem como avaliar a reação de enfermos com esta patologia frente a Escala de Qualidade de Vida desenvolvida por Font - 1988 (Costa Neto, 1997). Participaram do estudo 43 pacientes do Serviço de Cirurgia de Cabeça e Pescoço do Hospital Araújo Jorge - ACCG, que foram abordados individualmente na ocasião da consulta médica ou durante a internação hospitalar. Houve o predomínio de casos masculinos (55,8 por cento) sobre os femininos (44,2 por cento), a maioria em tratamento cirúrgico exclusivo (60 por cento), com idade entre 51 e 60 anos (28 por cento), com nenhuma (21 por cento) ou pouca escolarização (36 por cento). Cerca de 44 por cento nao trabalhava devido ao câncer. As neoplasias mais freqüentes eram da boca (25 por cento), e tireóide (19 por cento) e laringe (16 por cento). Na subescala (S-E) Sintomas, predominaram os fatores dor (38 por cento) e naúseas (23 por cento). Na S-E Dificuldades nos Hábitos Cotidianos, as atividades laborais (62 por cento). Na S-E Dificuldades Sociais/Familiares, preocupação com os filhos (60 por cento) e preocupações econômicas (58 por cento). Na S-E Fatores Psicológicos, Insatisfação com o Próprio Corpo (54 por cento) e Medo (49 por cento). No geral, houve uma perda média de 35 por cento na QV dos enfermos. Conclui-se que a Escala de QV de Font é apropriada para sujeitos com câncer de cabeça e pescoço, mas sugere-se associá-la a entrevistas semi-estruturadas, uma vez que as dimensões de significado não são avaliadas por instrumentos mais objetivos.

Interaction between tobacco and alcohol consumption and the risk of cancers of the upper aero-digestive tract in Brazil.

The authors investigated the joint effects of tobacco and alcohol consumption on the risk of squamous cell carcinomas of the upper aero-digestive tract (UADT) using data from a hospital-based case-control study conducted in southern Brazil, 1986-1989. A total of 784 cases of cancers of the mouth, pharynx, and larynx and 1,578 non-cancer controls matched on age, sex, hospital catchment area, and period of admission were interviewed about their smoking and drinking habits and other characteristics. Using logistic regression, evidence was found for interaction between the cumulative exposures for smoking and alcohol on UADT cancer risk. The joint effects for pharyngeal cancers exceeded the levels expected under a multiplicative model for moderate smokers (p = 0.007). There was little statistical evidence, however, for interaction on cancers of the mouth (p = 0.28) or larynx (p = 0.95). Among never smokers, heavy drinkers had 9.2 times (95% confidence interval 1.7, 48.5) greater risk of cancers of mouth, pharynx, and supraglottis than never drinkers, with a dose-response trend (p = 0.013) with cumulative consumption. The authors conclude that the interaction occurring in the pharynx between smoking and alcohol on UADT cancers is not uniform, with varying effects depending on the level of smoking exposure. Alcohol may act as both a promoter for tobacco and as an independent risk factor.

Relationship between dental factors and risk of upper aerodigestive tract cancer.

We examined the relationship between dental health variables and risk of upper aerodigestive tract (UADT) cancers in a case-control study in Southern Brazil. The study population included 717 cases of cancers of the mouth, pharynx, and larynx and 1434 controls matched on age, gender, period of admission and study site. The association with dental factors was investigated by conditional logistic regression using extensive adjustment for a priori and empirical confounders, including tobacco and alcohol consumption, diet and sociodemographic variables. Lifetime use of dentures was not associated with risk of any UADT cancer, but history of oral sores secondary to ill-fitting dentures was associated with cancers of the mouth (odds ratio [OR] = 2.3, 95% confidence interval [CI] 1.2-4.6) and of the pharynx (OR = 2.7, 95% CI 1.1-6.2) among those using dentures. The association for mouth cancers was restricted primarily to an increased risk of tongue neoplasms (OR = 9.1, 95% CI 1.9-43.4). Less than daily tooth brushing frequency was also associated with risk of cancer of the tongue (OR = 2.1, 95% CI 1.0-4.3) and of other parts of the mouth (OR = 2.4, 95% CI 1.0-5.4). Having broken teeth was not significantly associated with risk of UADT cancer of any site. We conclude that poor oral hygiene due to infrequent tooth brushing and sores caused by dentures are risk factors for cancer of the mouth and that these associations are unlikely to be due to insufficient control of confounding.

137Cesium-induced chromosome aberrations analyzed by fluorescence in situ hybridization: eight years follow up of the Goiânia radiation accident victims.

The radiation accident in focus here occurred in a section of Goiânia (Brazil) where more than a hundred individuals were contaminated with 137Cesium on September 1987. In order to estimate the absorbed radiation doses, initial frequencies of dicentrics and rings were determined in 129 victims [A.T. Ramalho, PhD Thesis, Subsidios a tecnica de dosimetria citogenetica gerados a partir da analise de resultados obtidos com o acidente radiologico de Goiânia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 1992]. We have followed some of these victims cytogenetically over the years seeking for parameters that could be used as basis for retrospective radiation dosimetry. Our data on translocation frequencies obtained by fluorescence in situ hybridization (FISH) could be directly compared to the baseline frequencies of dicentrics available for those same victims. Our results provided valuable information on how precise these estimates are. The frequencies of translocations observed years after the radiation exposure were two to three times lower than the initial dicentrics frequencies, the differences being larger at higher doses (>1 Gy). The accuracy of such dose estimates might be increased by scoring sufficient amount of cells. However, factors such as the persistence of translocation carrying lymphocytes, translocation levels not proportional to chromosome size, and inter-individual variation reduce the precision of these estimates.

Relationship between dental factors and risk of upper aerodigestive tract cancer / Relação entre os fatores dentais e risco de cancer no trato aero-digestivo alto

We examined the relationship between dental health variables and risk of upper aerodigestive tract (UADT) cancers in a case-control study in Southern Brazil. The study population included 717 cases of cancers of the mouth, pharynx, and larynx and 1434 controls matched on age, gender, period of admission and study site. The association with dental factors was investigated by conditional logistic regression using extensive adjustment for a priori and empirical confounders, including tobacco and alcohol consumption, diet and sociodemographic variables. Lifetime use of dentures was not associated with risk of any UADT cancer, but history of oral sores secondary to ill-fitting dentures was associated with cancers of the mouth (odds ratio [OR] = 2.3, 95 per cent confidence interval [CI] 1.2-4.6) and of the pharynx (OR = 2.7, 95 per cent CI 1.1-6.2) among those using dentures...