RESUMO
BACKGROUND: Melanoma aetiology has been proposed to have two pathways, which are determined by naevi and type of sun exposure and related to the anatomical site where melanoma develops. OBJECTIVES: We examined associations with melanoma by anatomical site for a comprehensive set of risk factors including pigmentary and naevus phenotypes, ultraviolet radiation exposure and polygenic risk. METHODS: We analysed harmonized data from 2617 people with incident first invasive melanoma and 975 healthy controls recruited through two population-based case-control studies in Australia and the UK. Questionnaire data were collected by interview using a single protocol, and pathway-specific polygenic risk scores were derived from DNA samples. We estimated adjusted odds ratios using unconditional logistic regression that compared melanoma cases at each anatomical site with all controls. RESULTS: When cases were compared with control participants, there were stronger associations for many naevi vs. no naevi for melanomas on the trunk, and upper and lower limbs than on the head and neck (P-heterogeneity < 0·001). Very fair skin (vs. olive/brown skin) was more weakly related to melanoma on the trunk than to melanomas at other sites (P-heterogeneity = 0·04). There was no significant difference by anatomical site for polygenic risk. Increased weekday sun exposure was positively associated with melanoma on the head and neck but not on other sites. CONCLUSIONS: We found evidence of aetiological heterogeneity for melanoma, supporting the dual pathway hypothesis. These findings enhance understanding of risk factors for melanoma and can guide prevention and skin examination education and practices.
Assuntos
Melanoma , Neoplasias Cutâneas , Austrália/epidemiologia , Humanos , Melanoma/etiologia , Melanoma/genética , Fatores de Risco , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/genética , Raios UltravioletaRESUMO
BACKGROUND: Melanoma risk prediction models could be useful for matching preventive interventions to patients' risk. OBJECTIVES: To develop and validate a model for incident first-primary cutaneous melanoma using clinically assessed risk factors. METHODS: We used unconditional logistic regression with backward selection from the Australian Melanoma Family Study (461 cases and 329 controls) in which age, sex and city of recruitment were kept in each step, and we externally validated it using the Leeds Melanoma Case-Control Study (960 cases and 513 controls). Candidate predictors included clinically assessed whole-body naevi and solar lentigines, and self-assessed pigmentation phenotype, sun exposure, family history and history of keratinocyte cancer. We evaluated the predictive strength and discrimination of the model risk factors using odds per age- and sex-adjusted SD (OPERA) and the area under curve (AUC), and calibration using the Hosmer-Lemeshow test. RESULTS: The final model included the number of naevi ≥ 2 mm in diameter on the whole body, solar lentigines on the upper back (a six-level scale), hair colour at age 18 years and personal history of keratinocyte cancer. Naevi was the strongest risk factor; the OPERA was 3·51 [95% confidence interval (CI) 2·71-4·54] in the Australian study and 2·56 (95% CI 2·23-2·95) in the Leeds study. The AUC was 0·79 (95% CI 0·76-0·83) in the Australian study and 0·73 (95% CI 0·70-0·75) in the Leeds study. The Hosmer-Lemeshow test P-value was 0·30 in the Australian study and < 0·001 in the Leeds study. CONCLUSIONS: This model had good discrimination and could be used by clinicians to stratify patients by melanoma risk for the targeting of preventive interventions. What's already known about this topic? Melanoma risk prediction models may be useful in prevention by tailoring interventions to personalized risk levels. For reasons of feasibility, time and cost many melanoma prediction models use self-assessed risk factors. However, individuals tend to underestimate their naevus numbers. What does this study add? We present a melanoma risk prediction model, which includes clinically-assessed whole-body naevi and solar lentigines, and self-assessed risk factors including pigmentation phenotype and history of keratinocyte cancer. This model performs well on discrimination, the model's ability to distinguish between individuals with and without melanoma, and may assist clinicians to stratify patients by melanoma risk for targeted preventive interventions.
Assuntos
Lentigo , Melanoma , Neoplasias Cutâneas , Adolescente , Austrália/epidemiologia , Estudos de Casos e Controles , Humanos , Lentigo/epidemiologia , Melanoma/diagnóstico , Melanoma/epidemiologia , Melanoma/etiologia , Fatores de Risco , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/etiologiaRESUMO
BACKGROUND: Guidelines for follow-up of patients with melanoma are based on limited evidence. OBJECTIVES: To guide skin surveillance, we developed a risk prediction model for subsequent primary melanomas, using demographic, phenotypical, histopathological, sun exposure and genomic risk factors. METHODS: Using Cox regression frailty models, we analysed data for 2613 primary melanomas from 1266 patients recruited to the population-based Genes, Environment and Melanoma study in New South Wales, Australia, with a median of 14 years' follow-up via the cancer registry. Discrimination and calibration were assessed. RESULTS: The median time to diagnosis of a subsequent primary melanoma decreased with each new primary melanoma. The final model included 12 risk factors. Harrell's C-statistic was 0·73 [95% confidence interval (CI) 0·68-0·77], 0·65 (95% CI 0·62-0·68) and 0·65 (95% CI 0·61-0·69) for predicting second, third and fourth primary melanomas, respectively. The risk of a subsequent primary melanoma was 4·75 times higher (95% CI 3·87-5·82) for the highest vs. the lowest quintile of the risk score. The mean absolute risk of a subsequent primary melanoma within 5 years was 8·0 ± SD 4.1% after the first primary melanoma, and 46·8 ± 15·0% after the second, but varied substantially by risk score. CONCLUSIONS: The risk of developing a subsequent primary melanoma varies considerably between individuals and is particularly high for those with two or more primary melanomas. The risk prediction model and its associated nomograms enable estimation of the absolute risk of subsequent primary melanoma, on the basis of on an individual's risk factors, and can be used to tailor surveillance intensity, communicate risk and provide patient education. What's already known about this topic? Current guidelines for the frequency and length of follow-up to detect new primary melanomas in patients with one or more previous primary melanomas are based on limited evidence. People with one or more primary melanomas have, on average, a higher risk of developing another primary invasive melanoma, compared with the general population, but an accurate way of estimating individual risk is needed. What does this study add? We provide a comprehensive risk prediction model for subsequent primary melanomas, using data from 1266 participants with melanoma (2613 primary melanomas), over a median 14 years' follow-up. The model includes 12 risk factors comprising demographic, phenotypical, histopathological and genomic factors, and sun exposure. It enables estimation of the absolute risk of subsequent primary melanomas, and can be used to tailor surveillance intensity, communicate individual risk and provide patient education.
Assuntos
Melanoma , Neoplasias Cutâneas , Austrália , Estudos de Coortes , Humanos , Melanoma/epidemiologia , Melanoma/etiologia , New South Wales/epidemiologia , Fatores de Risco , Neoplasias Cutâneas/epidemiologiaRESUMO
BACKGROUND: People at high risk of developing melanoma are usually identified by pigmentary and naevus phenotypes. OBJECTIVE: We examined whether associations of these phenotypes with melanoma risk differed by ambient sun exposure or participant characteristics in two population-based, case-control studies with comparable ancestry but different ambient sun exposure. METHODS: Data were analysed from 616 cases and 496 controls from the Australian Melanoma Family Study and 2012 cases and 504 controls from the Leeds (UK) case-control study. Questionnaire, interview and dermatological skin examination data were collected using the same measurement protocols. Relative risks were estimated as odds ratios using unconditional logistic regression, adjusted for potential confounders. RESULTS: Hair and skin colour were the strongest pigmentary phenotype risk factors. All associations of pigmentary phenotype with melanoma risk were similar across countries. The median number of clinically assessed naevi was approximately three times higher in Australia than Leeds, but the relative risks for melanoma associated with each additional common or dysplastic naevus were higher for Leeds than Australia, especially for naevi on the upper and lower limbs. Higher naevus counts on the head and neck were associated with a stronger relative risk for melanoma for women than men. The two countries had similar relative risks for melanoma based on self-reported naevus density categories, but personal perceptions of naevus number differed by country. There was no consistent evidence of interactions between phenotypes on risk. CONCLUSIONS: Classifying people at high risk of melanoma based on their number of naevi should ideally take into account their country of residence, type of counts (clinical or self-reported), body site on which the naevus counts are measured and sex. The presence of naevi may be a stronger indicator of a genetic predisposition in the UK than in Australia based on less opportunity for sun exposure to influence naevus development.
Assuntos
Exposição Ambiental , Melanoma/etnologia , Nevo Pigmentado/etnologia , Neoplasias Cutâneas/etnologia , Pigmentação da Pele , Luz Solar , Adolescente , Adulto , Idoso , Austrália/epidemiologia , Estudos de Casos e Controles , Extremidades , Feminino , Cor de Cabelo , Humanos , Masculino , Pessoa de Meia-Idade , Nevo Pigmentado/patologia , Fenótipo , Medição de Risco , Fatores de Risco , Fatores Sexuais , Neoplasias Cutâneas/patologia , Carga Tumoral , Reino Unido/epidemiologia , População Branca , Adulto JovemRESUMO
BACKGROUND: Parental occupational exposures have been associated with childhood brain tumours (CBT), but results are inconsistent. Few studies have studied CBT risk and parental solvent exposure, suggesting a possible association. We examined the association between CBT and parental occupational exposure to solvents in a case-control study. METHODS: Parents of 306 cases and 950 controls completed detailed occupational histories. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for both maternal and paternal exposure to benzene, other aromatics, aliphatics and chlorinated solvents in key time periods relative to the birth of their child. Adjustments were made for matching variables (child's age, sex and state of residence), best parental education and occupational exposure to diesel exhaust. RESULTS: An increased risk of CBT was observed with maternal occupational exposures to chlorinated solvents (OR=8.59, 95% CI 0.94-78.9) any time before birth. Paternal exposure to solvents in the year before conception was associated with an increased CBT risk: OR=1.55 (95% CI 0.99-2.43). This increased risk appeared to be mainly attributable to exposure to aromatic solvents: OR=2.72 (95% CI 0.94-7.86) for benzene and OR=1.76 (95% CI 1.10-2.82) for other aromatics. CONCLUSIONS: Our results indicate that parental occupational exposures to solvents may be related to an increased risk of CBT.
Assuntos
Neoplasias Encefálicas/etiologia , Exposição Materna/efeitos adversos , Exposição Ocupacional/efeitos adversos , Exposição Paterna/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/etiologia , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Gravidez , Risco , Solventes/efeitos adversosRESUMO
Despite the widespread use of ambient ultraviolet radiation (UVR) as a proxy measure of personal exposure to UVR, the relationship between the two is not well-defined. This paper examines the effects of season and latitude on the relationship between ambient UVR and personal UVR exposure. We used data from the AusD Study, a multi-centre cross-sectional study among Australian adults (18-75 years), where personal UVR exposure was objectively measured using polysulphone dosimeters. Data were analysed for 991 participants from 4 Australian cities of different latitude: Townsville (19.3°S), Brisbane (27.5°S), Canberra (35.3°S) and Hobart (42.8°S). Daily personal UVR exposure varied from 0.01 to 21 Standard Erythemal Doses (median = 1.1, IQR: 0.5-2.1), on average accounting for 5% of the total available ambient dose. There was an overall positive correlation between ambient UVR and personal UVR exposure (r = 0.23, p < 0.001). However, the correlations varied according to season and study location: from strong correlations in winter (r = 0.50) and at high latitudes (Hobart, r = 0.50; Canberra, r = 0.39), to null or even slightly negative correlations, in summer (r = 0.01) and at low latitudes (Townsville, r = -0.06; Brisbane, r = -0.16). Multiple regression models showed significant effect modification by season and location. Personal exposure fraction of total available ambient dose was highest in winter (7%) and amongst Hobart participants (7%) and lowest in summer (1%) and in Townsville (4%). These results suggest season and latitude modify the relationship between ambient UVR and personal UVR exposure. Ambient UVR may not be a good indicator for personal exposure dose under some circumstances.
Assuntos
Exposição Ambiental , Estações do Ano , Raios Ultravioleta , Adolescente , Adulto , Idoso , Austrália , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Monitoramento de Radiação , Análise de Regressão , Luz Solar , Adulto JovemRESUMO
BACKGROUND: Despite the association with more advanced nodal stage, patients with human papillomavirus (HPV) positive oropharyngeal cancers have better outcomes. We examined whether the HPV can modify the effect of known prognostic factors in tonsillar cancer. PATIENTS AND METHODS: A total of 489 patients from 10 centres were followed up for recurrence or death for a median of 3.2 years. Determinants of the rate of locoregional recurrence, death from tonsillar cancer and overall survival were modelled using Cox regression. RESULTS: The prognostic value of T and N stages were modified by HPV as indicated by statistically significant interaction terms. After adjusting for age, gender and treatment, T stage appeared relevant only for HPV-positive cancers (where a higher T stage was associated with worse outcomes). There was some evidence that N stage was a more relevant prognostic factor for HPV-negative than -positive cancers. There was no evidence that the HPV modifies the effect of age, gender or grade on outcomes. CONCLUSIONS: This study suggests that the prognostic significance of the conventional staging system in tonsillar cancer is modified by HPV.
Assuntos
Papillomaviridae/fisiologia , Neoplasias Tonsilares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Papillomaviridae/isolamento & purificação , Prognóstico , Neoplasias Tonsilares/virologiaRESUMO
BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants that are potentially harmful to health. We examined if rates of selected cancers and causes of deaths were elevated in three Australian communities with local environmental contamination caused by firefighting foams containing PFAS. The affected Australian communities were Katherine in Northern Territory, Oakey in Queensland and Williamtown in New South Wales. METHODS: All residents identified in the Medicare Enrolment File (1983-2019)-a consumer directory for Australia's universal healthcare-who ever lived in an exposure area (Katherine, Oakey and Williamtown), and a sample of those who ever lived in selected comparison areas, were linked to the Australian Cancer Database (1982-2017) and National Death Index (1980-2019). We estimated standardised incidence ratios (SIRs) for 23 cancer outcomes, four causes of death and three control outcomes, adjusting for sex, age and calendar time of diagnosis. FINDINGS: We observed higher rates of prostate cancer (SIR=1·76, 95 % confidence interval (CI) 1·36-2·24) in Katherine; laryngeal cancer (SIR=2·71, 95 % CI 1·30-4·98), kidney cancer (SIR=1·82, 95 % CI 1·04-2·96) and coronary heart disease (CHD) mortality (SIR=1·81, 95 % CI 1·46-2·33) in Oakey; and lung cancer (SIR=1·83, 95 % CI 1·39-2·38) and CHD mortality (SIR=1·22, 95 % CI 1·01-1·47) in Williamtown. We also saw elevated SIRs for control outcomes. SIRs for all other outcomes and overall cancer were similar across exposure and comparison areas. INTERPRETATION: There was limited evidence to support an association between living in a PFAS exposure area and risks of cancers or cause-specific deaths.
Assuntos
Fluorocarbonos , Neoplasias Renais , Neoplasias , Neoplasias da Próstata , Masculino , Humanos , Idoso , Estudos de Coortes , Austrália/epidemiologia , Web Semântica , Programas Nacionais de Saúde , Incidência , Neoplasias da Próstata/complicações , Neoplasias Renais/complicaçõesRESUMO
OBJECTIVES: Observational studies have suggested that a higher 25-hydroxyvitamin D concentration may be associated with longer telomere length; however, this has not been investigated in randomised controlled trials. We conducted an ancillary study within a randomised, double-blind, placebo-controlled trial of monthly vitamin D (the D-Health Trial) for the prevention of all-cause mortality, conducted from 2014 to 2020, to assess the effect of vitamin D supplementation on telomere length (measured as the telomere to single copy gene (T/S) ratio). DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION: Participants were Australians aged 60-84 years and we randomly selected 1,519 D-Health participants (vitamin D: n=744; placebo: n=775) for this analysis. We used quantitative polymerase chain reaction to measure the relative telomere length (T/S ratio) at 4 or 5 years after randomisation. We compared the mean T/S ratio between the vitamin D and placebo groups to assess the effect of vitamin D supplementation on relative telomere length, using a linear regression model with adjustment for age, sex, and state which were used to stratify the randomisation. RESULTS: The mean T/S ratio was 0.70 for both groups (standard deviation 0.18 and 0.16 for the vitamin D and placebo groups respectively). The adjusted mean difference (vitamin D minus placebo) was -0.001 (95% CI -0.02 to 0.02). There was no effect modification by age, sex, body mass index, or predicted baseline 25-hydroxyvitamin D concentration. CONCLUSION: In conclusion, routinely supplementing older adults, who are largely vitamin D replete, with monthly doses of vitamin D is unlikely to influence telomere length.
Assuntos
Vitamina D , Vitaminas , Humanos , Idoso , Austrália , Vitaminas/farmacologia , Vitaminas/uso terapêutico , Calcifediol , Telômero , Suplementos Nutricionais , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: Men diagnosed with localised prostate cancer (LPC) face difficult choices between treatment options that can cause persistent problems with sexual, urinary and bowel function. Controlled trial evidence about the survival benefits of the full range of treatment alternatives is limited, and patients' views on the survival gains that might justify these problems have not been quantified. METHODS: A discrete choice experiment (DCE) was administered in a random subsample (n=357, stratified by treatment) of a population-based sample (n=1381) of men, recurrence-free 3 years after diagnosis of LPC, and 65 age-matched controls (without prostate cancer). Survival gains needed to justify persistent problems were estimated by substituting side effect and survival parameters from the DCE into an equation for compensating variation (adapted from welfare economics). RESULTS: Median (2.5, 97.5 centiles) survival benefits needed to justify severe erectile dysfunction and severe loss of libido were 4.0 (3.4, 4.6) and 5.0 (4.9, 5.2) months. These problems were common, particularly after androgen deprivation therapy (ADT): 40 and 41% overall (n=1381) and 88 and 78% in the ADT group (n=33). Urinary leakage (most prevalent after radical prostatectomy (n=839, mild 41%, severe 18%)) needed 4.2 (4.1, 4.3) and 27.7 (26.9, 28.5) months survival benefit, respectively. Mild bowel problems (most prevalent (30%) after external beam radiotherapy (n=106)) needed 6.2 (6.1, 6.4) months survival benefit. CONCLUSION: Emerging evidence about survival benefits can be assessed against these patient-based benchmarks. Considerable variation in trade-offs among individuals underlines the need to inform patients of long-term consequences and incorporate patient preferences into treatment decisions.
Assuntos
Preferência do Paciente , Neoplasias da Próstata/terapia , Idoso , Antagonistas de Androgênios/efeitos adversos , Intervalo Livre de Doença , Disfunção Erétil/epidemiologia , Humanos , Enteropatias/epidemiologia , Masculino , Pessoa de Meia-Idade , Prostatectomia/efeitos adversos , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/psicologia , Qualidade de Vida , Radioterapia/efeitos adversos , Doenças Urológicas/epidemiologiaRESUMO
OBJECTIVES: The objective of this study was to examine the associations of brain tumours with radio frequency (RF) fields from mobile phones. METHODS: Patients with brain tumour from the Australian, Canadian, French, Israeli and New Zealand components of the Interphone Study, whose tumours were localised by neuroradiologists, were analysed. Controls were matched on age, sex and region and allocated the 'tumour location' of their matched case. Analyses included 553 glioma and 676 meningioma cases and 1762 and 1911 controls, respectively. RF dose was estimated as total cumulative specific energy (TCSE; J/kg) absorbed at the tumour's estimated centre taking into account multiple RF exposure determinants. RESULTS: ORs with ever having been a regular mobile phone user were 0.93 (95% CI 0.73 to 1.18) for glioma and 0.80 (95% CI 0.66 to 0.96) for meningioma. ORs for glioma were below 1 in the first four quintiles of TCSE but above 1 in the highest quintile, 1.35 (95% CI 0.96 to 1.90). The OR increased with increasing TCSE 7+ years before diagnosis (p-trend 0.01; OR 1.91, 95% CI 1.05 to 3.47 in the highest quintile). A complementary analysis in which 44 glioma and 135 meningioma cases in the most exposed area of the brain were compared with gliomas and meningiomas located elsewhere in the brain showed increased ORs for tumours in the most exposed part of the brain in those with 10+ years of mobile phone use (OR 2.80, 95% CI 1.13 to 6.94 for glioma). Patterns for meningioma were similar, but ORs were lower, many below 1.0. CONCLUSIONS: There were suggestions of an increased risk of glioma in long-term mobile phone users with high RF exposure and of similar, but apparently much smaller, increases in meningioma risk. The uncertainty of these results requires that they be replicated before a causal interpretation can be made.
Assuntos
Neoplasias Encefálicas/epidemiologia , Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Neoplasias Induzidas por Radiação/epidemiologia , Doses de Radiação , Ondas de Rádio/efeitos adversos , Adulto , Algoritmos , Austrália/epidemiologia , Canadá/epidemiologia , Estudos de Casos e Controles , Feminino , França/epidemiologia , Glioma/epidemiologia , Humanos , Israel/epidemiologia , Modelos Logísticos , Masculino , Neoplasias Meníngeas/epidemiologia , Meningioma/epidemiologia , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Razão de Chances , Fatores de Risco , Fatores de TempoRESUMO
OBJECTIVE: This study examines the prognostic significance of human papillomavirus (HPV) in patients with locally advanced oropharyngeal squamous cell carcinoma (SCC) treated primarily with surgery or definitive radiotherapy. METHODS: One hundred and ninety-eight patients with Stage 3/4 SCC were followed up for recurrence in any form or death from any cause for between 1 and 235 months after diagnosis. HPV status was determined using HPV E6-targeted multiplex real-time PCR/p16 immunohistochemistry. Determinants of recurrence and mortality hazards were modelled using Cox's regression with censoring at follow-up dates. RESULTS: Forty-two per cent of cancers were HPV-positive (87% type 16). HPV predicted loco-regional control, event-free survival and overall survival in multivariable analysis. Within the surgery with adjuvant radiotherapy (n=110), definitive radiotherapy-alone (n=24) and definitive radiotherapy with chemotherapy (n=47) groups, patients with HPV-positive cancers were one-third or less as likely to have loco-regional recurrence, an event or to die of any cause as those with HPV-negative cancers after adjusting for age, gender, tumour grade, AJCC stage and primary site. The 14 patients treated with surgery alone were considered too few for multivariable analysis. CONCLUSION: HPV status predicts better outcome in oropharyngeal cancer treated with surgery plus adjuvant radiotherapy as well as with definitive radiation therapy±chemotherapy.
Assuntos
Alphapapillomavirus/isolamento & purificação , Papillomavirus Humano 6/isolamento & purificação , Neoplasias Orofaríngeas/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/prevenção & controle , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/tratamento farmacológico , Neoplasias Orofaríngeas/mortalidade , Neoplasias Orofaríngeas/radioterapia , Neoplasias Orofaríngeas/cirurgia , Valor Preditivo dos Testes , Recidiva , Neoplasias da Língua/patologia , Neoplasias da Língua/terapia , Neoplasias Tonsilares/patologia , Neoplasias Tonsilares/terapiaRESUMO
The relation between intrauterine growth and risk of childhood acute lymphoblastic leukemia was investigated in an Australian population-based case-control study that included 347 cases and 762 controls aged <15 years recruited from 2003 to 2006. Information on proportion of optimal birth weight, a measure of the appropriateness of fetal growth, was collected from mothers by questionnaire. Data were analyzed by using logistic regression. Risk of acute lymphoblastic leukemia was positively associated with proportion of optimal birth weight; the odds ratio for a 1-standard-deviation increase in proportion of optimal birth weight was 1.18 (95% confidence interval: 1.04, 1.35) after adjustment for the matching variables and potential confounders. This association was also present among children who did not have a high birth weight, suggesting that accelerated growth, rather than high birth weight per se, is associated with risk of acute lymphoblastic leukemia. Similar associations between proportion of optimal birth weight and acute lymphoblastic leukemia were observed for both sexes and across age groups and leukemia subtypes. Results of this study confirm earlier findings of a positive association between rapidity of fetal growth and subsequent risk of acute lymphoblastic leukemia in childhood, and they are consistent with a role for insulin-like growth factors in the causal pathway.
Assuntos
Peso ao Nascer , Desenvolvimento Fetal , Retardo do Crescimento Fetal , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Adolescente , Austrália/epidemiologia , Estudos de Casos e Controles , Intervalos de Confiança , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Modelos Logísticos , Razão de Chances , Leucemia-Linfoma Linfoblástico de Células Precursoras/etiologia , Medição de Risco , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure for epidemiological studies, we assessed determinants of mobile phone output power in a multinational study. METHODS: More than 500 volunteers in 12 countries used Global System for Mobile communications software-modified phones (GSM SMPs) for approximately 1 month each. The SMPs recorded date, time, and duration of each call, and the frequency band and output power at fixed sampling intervals throughout each call. Questionnaires provided information on the typical circumstances of an individual's phone use. Linear regression models were used to analyse the influence of possible explanatory variables on the average output power and the percentage call time at maximum power for each call. RESULTS: Measurements of over 60,000 phone calls showed that the average output power was approximately 50% of the maximum, and that output power varied by a factor of up to 2 to 3 between study centres and network operators. Maximum power was used during a considerable proportion of call time (39% on average). Output power decreased with increasing call duration, but showed little variation in relation to reported frequency of use while in a moving vehicle or inside buildings. Higher output powers for rural compared with urban use of the SMP were observed principally in Sweden where the study covered very sparsely populated areas. CONCLUSIONS: Average power levels are substantially higher than the minimum levels theoretically achievable in GSM networks. Exposure indices could be improved by accounting for average power levels of different telecommunications systems. There appears to be little value in gathering information on circumstances of phone use other than use in very sparsely populated regions.
Assuntos
Telefone Celular/estatística & dados numéricos , Exposição Ambiental/análise , Ondas de Rádio , Adulto , Estudos de Casos e Controles , Exposição Ambiental/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Monitoramento de Radiação/métodos , Saúde da População Rural/estatística & dados numéricos , Fatores de Tempo , Saúde da População Urbana/estatística & dados numéricosRESUMO
AIM: To validate short term recall of mobile phone use within Interphone, an international collaborative case control study of tumours of the brain, acoustic nerve, and salivary glands related to mobile telephone use. METHODS: Mobile phone use of 672 volunteers in 11 countries was recorded by operators or through the use of software modified phones, and compared to use recalled six months later using the Interphone study questionnaire. Agreement between recalled and actual phone use was analysed using both categorical and continuous measures of number and duration of phone calls. RESULTS: Correlations between recalled and actual phone use were moderate to high (ranging from 0.5 to 0.8 across countries) and of the same order for number and duration of calls. The kappa statistic demonstrated fair to moderate agreement for both number and duration of calls (weighted kappa ranging from 0.20 to 0.60 across countries). On average, subjects underestimated the number of calls per month (geometric mean ratio of recalled to actual = 0.92, 95% CI 0.85 to 0.99), whereas duration of calls was overestimated (geometric mean ratio = 1.42, 95% CI 1.29 to 1.56). The ratio of recalled to actual use increased with level of use, showing underestimation in light users and overestimation in heavy users. There was substantial heterogeneity in this ratio between countries. Inter-individual variation was also large, and increased with level of use. CONCLUSIONS: Volunteer subjects recalled their recent phone use with moderate systematic error and substantial random error. This large random error can be expected to reduce the power of the Interphone study to detect an increase in risk of brain, acoustic nerve, and parotid gland tumours with increasing mobile phone use, if one exists.
Assuntos
Telefone Celular/estatística & dados numéricos , Rememoração Mental , Estudos de Casos e Controles , Humanos , Variações Dependentes do Observador , Reprodutibilidade dos TestesRESUMO
Indigenous Australians with cancer are diagnosed with more advanced disease and have lower survival than other Australians. To investigate reasons for these differences. Retrospective cohort study of 1197 indigenous and nonindigenous people in the Northern Territory diagnosed with cancers of the colon and rectum, lung, breast, cervix and non-Hodgkin lymphoma between 1991 and 2000. Outcome measures were stage at diagnosis and relative risk of cancer death. Indigenous people compared with nonindigenous people had higher relative odds of advanced stage of cancer at diagnosis (relative odds 1.9, 95% CI 1.3-2.7) for four cancers but lower relative odds for lung cancer (relative odds 0.3, 95% CI 0.2-0.5). None of the potentially contributing factors examined could explain this difference. Risk of cancer death (adjusted for cancer type and age and stage at diagnosis) was higher in indigenous than in nonindigenous people (relative risk 1.7, 95% CI 1.4-2.1). This difference, however, was confined to indigenous people with an indigenous first language (relative risk 2.9, 95% CI 2.2-3.8). Adjustment for cancer treatment variables further reduced but did not eliminate this higher risk of death. Although more advanced stage at diagnosis appeared to be a sufficient explanation for poorer cancer outcome in indigenous people whose first language was English, poorer treatment also contributed to, but was still not sufficient to explain, poorer outcome in those who had an indigenous first language. Other factors, possibly including communication difficulties, knowledge of and attitudes to cancer symptoms and treatment and social and cultural 'distance' from mainstream health services, may also be involved.
Assuntos
Serviços de Saúde do Indígena/normas , Neoplasias/diagnóstico , Neoplasias/terapia , Grupos Populacionais/etnologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neoplasias/epidemiologia , Northern Territory/etnologia , Estudos Retrospectivos , Taxa de Sobrevida/tendênciasRESUMO
The roles of constitutional factors and benign nevi in causation of malignant melanoma were examined in a case-control study of 511 patients and 511 matched controls in Western Australia. The strongest risk factor was the number of palpable benign nevi on a subject's arms. Compared to the risk of melanomas for persons having no palpable nevi on the arms, the relative risk of melanoma was 2.0 for persons with 1-4 nevi, 4.0 for persons with 5-9 nevi, and 11.3 for persons with 10 or more nevi (P less than .0001). Of the several pigmentary traits known to have associations with melanoma, inability to tan was the most important. Susceptibility to sunburn and hair color also had significant effects that were independent of tanning ability; however, after these traits were controlled, measured skin color and eye color had no additional effects. A reduced risk of melanoma was observed in persons having two or more Southern European grandparents [odds ratio (OR) = 0.39; P = .025]. Persons of Celtic origin did not have a significantly increased risk (OR = 1.18). Possession of one or more affected blood relatives was related to an increased risk of melanoma (OR = 2.69; P less than .0001). The effects of pigmentary traits, benign nevi, ethnic origin, and family history as risk factors were largely independent of one another.
Assuntos
Etnicidade , Melanoma/epidemiologia , Nevo/complicações , Pigmentação da Pele , Austrália , Humanos , Melanoma/etiologia , Melanoma/genética , Nevo/patologia , Risco , Neoplasias Cutâneas/epidemiologiaRESUMO
Evidence associating malignant melanoma with semiquantitative and questionnaire indicators of past sunlight exposure is presented from a case-control study of 511 patients and 511 matched control subjects in Western Australia. That melanoma is related to sun exposure was supported by associations with actinic skin damage graded by cutaneous microtopography, history of nonmelanotic skin cancer, duration of residence of migrants to Australia, and mean annual hours of bright sunshine received at locations where the subjects had resided. Separate analyses of histogenetic subtypes revealed that Hutchinson's melanotic freckle melanoma had the strongest associations with indicators of sunlight exposure. For superficial spreading melanoma, a specific relationship was observed with age at arrival as against duration of residence in Australia. Migrants arriving before age 10 years appeared to have a risk similar to that of native-born Australians, whereas the estimated incidence in those arriving after age 15 years was around one-quarter of the native-born rate, with arrival at later ages giving no additional advantage. Control subjects arriving in Australia before age 10 years had an increased number of nevi on their arms, suggesting that sun exposure in early life may be a factor in nevus production and, therefore, a determinant of later potential to develop superficial spreading melanoma.