1378The effect of vitamin D supplementation on acute respiratory infection -analysis of the D-Health Trial

Background

Observational studies link vitamin D deficiency with acute respiratory tract infection (ARTI) but results from randomised controlled trials are heterogeneous.

Methods

We used data from The D-Health Trial (N = 21,315); ARTI was a pre-specified trial outcome. Participants were men and women aged 60 to 79 years (with volunteers aged up to 84 years), supplemented with monthly doses of 60,000 international units of vitamin D and followed for up to 5 years. Participants were asked to report occurrence of ARTI over the previous month via annual surveys, and a subset of participants completed 8-week respiratory symptom diaries in winter. We used regression models to estimate odds ratios, rate ratios and rate differences.

Results

Vitamin D supplementation did not reduce the risk of ARTI (survey OR 0.98, 95% CI 0.93 to 1.02; diary OR 0.98, 95% CI 0.83 to 1.15). Analyses of diary data showed that vitamin D reduced the average duration by 0.5 days (95% CI 0.2 to 0.7 days) and the average number of days with severe symptoms by 0.4 days (95% CI 0.3 to 0.6 days).

Conclusions

Monthly bolus doses of 60,000 IU of vitamin D did not reduce the overall risk of ARTI but slightly reduce the duration of symptoms in the general population.

Key messages

The reduction in the duration of symptoms suggests a potential impact of vitamin D on the immune response to infection.

515Association between hysterectomy and risk of thyroid cancer

Background

Hysterectomy (surgical removal of the uterus) has been consistently associated with increased thyroid cancer risk. While there may be a biologic explanation, increased ascertainment (over-diagnosis) because of greater healthcare use by women having this procedure might also contribute to the observed increased risk. We explored this association considering indications for hysterectomy, age at hysterectomy, and the potential for the association to be mediated by increased contact with health professionals or increased thyroid function testing.

Methods

We recruited 730 women diagnosed with thyroid cancer and 785 age-matched population controls. We estimated odds ratios (OR) using logistic regression to assess the associations and used causal mediation analysis to investigate potential mediation.

Results

Prior hysterectomy was associated with an increased thyroid cancer risk (OR = 1.55, 95% CI: 1.14-2.12). When stratified by indication for hysterectomy, the increased risk was apparent only among those who had undergone hysterectomy for bleeding disorders (OR = 1.79, 95% CI: 1.26-2.56). Additionally, the association varied by age at hysterectomy (<55 years, OR = 1.68, 95% CI: 1.22-2.31 versus ≥ 55 years, OR = 0.87, 95% CI: 0.42-1.81). Around 30% of the association was mediated by more frequent use of healthcare services.

Conclusions

Hysterectomy for bleeding disorders was associated with an increased risk of thyroid cancer among women and a moderate proportion of this appeared due to frequent medical contact.

Key messages

The way in which women use health services probably explains at least some of the association between hysterectomy and risk of thyroid cancer.

1466Vitamin D status before, during and after treatment and ovarian cancer survival

Background

Previous work found higher serum 25-hydroxyvitamin D (25(OH)D) [circulating form of vitamin D] concentrations at diagnosis were associated with longer survival in patients with ovarian cancer (OvCa). There was no evidence for an association with 25(OH)D after primary treatment, but power was limited. Our aim was to reassess this association in a larger sample, including measures collected during treatment and using techniques to deseasonalise 25(OH)D.

Methods

Participants were diagnosed between 2002-2006 and 2012-2015 from the Australian Ovarian Cancer Study (AOCS) and the Ovarian Cancer, Prognosis and Lifestyle (OPAL) study, respectively. 25(OH)D concentrations were available for 676 at diagnosis (AOCS), 805 during treatment (AOCS:208; OPAL:597) and 861 after completion of primary treatment and before recurrence (AOCS:342; OPAL:519); 1006 AOCS samples were included in the previous analysis. Sociodemographic, diet and lifestyle data came from questionnaires self-completed at recruitment, and clinical/survival data from medical records, supplemented with National Death Index linkage. We will use Cox regression and non-parametric models to examine associations with survival.

Results

Median 25(OH)D concentrations were lowest during treatment, intermediate at diagnosis and highest after treatment (AOCS 51, 64, and 71 nmol/L, respectively). 5-year survival was 50% in AOCS and 59% in OPAL. Updated survival results will be presented.

Conclusions

If the association is confirmed in this updated analysis, then increasing vitamin D concentrations may provide a way to improve survival following OvCa.

Key messages

Higher circulating vitamin D concentrations may improve survival in OvCa.

649Personal history of keratinocyte carcinoma is a marker of inherited cancer risk: Mendelian randomization analyses

Background

A personal history of keratinocyte carcinoma (KC) has been reported as a risk factor for developing subsequent primary cutaneous and non-cutaneous malignancies. However most evidence to date stems from observational studies which are prone to bias, confounding and reverse causation. Our aim was to examine this association using different Mendelian randomization (MR) approaches.

Methods

We performed a one-sample MR analysis using individual-level data from the UK Biobank (n = 394,306). This analysis was then validated in an independent dataset in the QSkin cohort (n = 16,896). Using 64 independent genetic variants known to be associated with KC, we generated a polygenic risk score (PRS) for each participant in the UK Biobank and the QSkin cohort. We then performed two-sample MR analyses using genome-wide association study (GWAS) summary statistics. We tested the association between genetically predicted KC and risk of subsequent cancer using logistic regression.

Results

Results from one-sample MR analyses in the UK Biobank indicated that a personal history of KC was significantly associated with cancer overall (excluding melanoma) (OR: 1.15, 95% CI: 1.10-1.20, per doubling the prevalence of KC). The results from the two-sample MR corroborate the findings from the one-sample MR, although the risk estimate was lower (OR: 1.05, 95% CI: 1.03-1.07).

Conclusions

Our MR analyses suggest that genetically predicted KC is a risk factor for developing subsequent primary malignancies.

Key messages

A personal history of KC may serve as a proxy marker of inherited cancer risk.

Bayesian copy number detection and association in large-scale studies

BACKGROUND

Germline copy number variants (CNVs) increase risk for many diseases, yet detection of CNVs and quantifying their contribution to disease risk in large-scale studies is challenging due to biological and technical sources of heterogeneity that vary across the genome within and between samples.

METHODS

We developed an approach called CNPBayes to identify latent batch effects in genome-wide association studies involving copy number, to provide probabilistic estimates of integer copy number across the estimated batches, and to fully integrate the copy number uncertainty in the association model for disease.

RESULTS

Applying a hidden Markov model (HMM) to identify CNVs in a large multi-site Pancreatic Cancer Case Control study (PanC4) of 7598 participants, we found CNV inference was highly sensitive to technical noise that varied appreciably among participants. Applying CNPBayes to this dataset, we found that the major sources of technical variation were linked to sample processing by the centralized laboratory and not the individual study sites. Modeling the latent batch effects at each CNV region hierarchically, we developed probabilistic estimates of copy number that were directly incorporated in a Bayesian regression model for pancreatic cancer risk. Candidate associations aided by this approach include deletions of 8q24 near regulatory elements of the tumor oncogene MYC and of Tumor Suppressor Candidate 3 (TUSC3).

CONCLUSIONS

Laboratory effects may not account for the major sources of technical variation in genome-wide association studies. This study provides a robust Bayesian inferential framework for identifying latent batch effects, estimating copy number, and evaluating the role of copy number in heritable diseases.

Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis

BACKGROUND

Randomised controlled trials (RCTs) exploring the potential of vitamin D to prevent acute respiratory infections have yielded mixed results. Individual participant data (IPD) meta-analysis has the potential to identify factors that may explain this heterogeneity.

OBJECTIVES

To assess the overall effect of vitamin D supplementation on the risk of acute respiratory infections (ARIs) and to identify factors modifying this effect.

DATA SOURCES

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, ClinicalTrials.gov and the International Standard Randomised Controlled Trials Number (ISRCTN) registry.

STUDY SELECTION

Randomised, double-blind, placebo-controlled trials of supplementation with vitamin D₃ or vitamin D₂ of any duration having incidence of acute respiratory infection as a prespecified efficacy outcome were selected.

STUDY APPRAISAL

Study quality was assessed using the Cochrane Collaboration Risk of Bias tool to assess sequence generation, allocation concealment, blinding of participants, personnel and outcome assessors, completeness of outcome data, evidence of selective outcome reporting and other potential threats to validity.

RESULTS

We identified 25 eligible RCTs (a total of 11,321 participants, aged from 0 to 95 years). IPD were obtained for 10,933 out of 11,321 (96.6%) participants. Vitamin D supplementation reduced the risk of ARI among all participants [adjusted odds ratio (aOR) 0.88, 95% confidence interval (CI) 0.81 to 0.96; heterogeneity p < 0.001]. Subgroup analysis revealed that protective effects were seen in individuals receiving daily or weekly vitamin D without additional bolus doses (aOR 0.81, 95% CI 0.72 to 0.91), but not in those receiving one or more bolus doses (aOR 0.97, 95% CI 0.86 to 1.10; p = 0.05). Among those receiving daily or weekly vitamin D, protective effects of vitamin D were stronger in individuals with a baseline 25-hydroxyvitamin D [25(OH)D] concentration of < 25 nmol/l (aOR 0.30, 95% CI 0.17 to 0.53) than in those with a baseline 25(OH)D concentration of ≥ 25 nmol/l (aOR 0.75, 95% CI 0.60 to 0.95; p = 0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (aOR 0.98, 95% CI 0.80 to 1.20; p = 0.83). The body of evidence contributing to these analyses was assessed as being of high quality.

LIMITATIONS

Our study had limited power to detect the effects of vitamin D supplementation on the risk of upper versus lower respiratory infection, analysed separately.

CONCLUSIONS

Vitamin D supplementation was safe, and it protected against ARIs overall. Very deficient individuals and those not receiving bolus doses experienced the benefit. Incorporation of additional IPD from ongoing trials in the field has the potential to increase statistical power for analyses of secondary outcomes.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013953.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The Potential of Ultraviolet Radiation Meters in Secondary Schools as a Sun Protection Intervention Mechanism for Adolescents

The aim of this pilot study was to assess whether the installation of ultraviolet radiation (UVR) meters in secondary schools has the potential to improve adolescents’ sun protection-related knowledge, attitudes, and behaviours and reduce their exposure to UVR during school hours. Data were collected from students at two schools via online pre- and post-intervention surveys, measurement of sunscreen usage, polysulfone UVR exposure badges, and photographs of the schoolyards to assess hat and shade use. Several operational issues limited the quantity and quality of data that could be collected, and findings were mixed. While there were no significant changes in either self-reported or observed sun protection behaviours, there were significant improvements in UVR knowledge among students at the intervention school, and reactions to the meter were highly favourable. Students reported consulting the meter regularly and using it to make decisions about their sun protection behaviours. Overall, the study results offer some support for the use of UVR meters in areas frequented by adolescents and provide insights into the process issues that are likely to need to be addressed when attempting to trial sun protection interventions in schools.

The Future Excess Fraction of Cancer Attributable to High Body Mass Index in Australia

Background: High body mass index (BMI > 25 kg/m2) has been found to be associated with an increased risk of many cancers, including cancers of the colon and rectum, liver, and pancreas. Aim: This study aimed to estimate the future burden of cancer resulting from current levels of overweight and obesity in Australia. Methods: The future excess fraction method was used to estimate the future burden of cancer among the proportion of the Australian adult population who were overweight or obese in 2016. Calculations were conducted for 13 cancer types, including cancers of the colon, rectum, kidney, and liver. Results: The cohort of 18.7 million adult Australians in 2016 will develop ∼7.6 million cancers over their lifetime. Of these, ∼402,500 cancers (5.3%) will be attributable to current levels of overweight and obese. The majority of these will be postmenopausal breast cancers (n = 72,300), kidney cancers (n = 59,200), and colon cancers (n = 55,100). More than a quarter of future endometrial cancers (30.3%) and esophageal adenocarcinomas (35.8%) will be attributable to high body mass index. Conclusion: A significant proportion of future cancers will result from current levels of high body mass index. Our estimates are not directly comparable to past estimates of the burden from overweight and obesity because they describe different quantities - future cancers in currently exposed vs current cancers due to past exposures. The results of this study provide us with relevant up-to-date information about how many cancers in Australia could be prevented.

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Objectives To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect.Design Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials.Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015.Eligibility criteria for study selection Randomised, double blind, placebo controlled trials of supplementation with vitamin D₃ or vitamin D₂ of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome.Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001). In subgroup analysis, protective effects were seen in those receiving daily or weekly vitamin D without additional bolus doses (adjusted odds ratio 0.81, 0.72 to 0.91) but not in those receiving one or more bolus doses (adjusted odds ratio 0.97, 0.86 to 1.10; P for interaction=0.05). Among those receiving daily or weekly vitamin D, protective effects were stronger in those with baseline 25-hydroxyvitamin D levels <25 nmol/L (adjusted odds ratio 0.30, 0.17 to 0.53) than in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (adjusted odds ratio 0.75, 0.60 to 0.95; P for interaction=0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted odds ratio 0.98, 0.80 to 1.20, P=0.83). The body of evidence contributing to these analyses was assessed as being of high quality.Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.Systematic review registration PROSPERO CRD42014013953.

Summary and recommendations from the Australasian guidelines for the management of pancreatic exocrine insufficiency

AIM

Because of increasing awareness of variations in the use of pancreatic exocrine replacement therapy, the Australasian Pancreatic Club decided it was timely to re-review the literature and create new Australasian guidelines for the management of pancreatic exocrine insufficiency (PEI).

METHODS

A working party of expert clinicians was convened and initially determined that by dividing the types of presentation into three categories for the likelihood of PEI (definite, possible and unlikely) they were able to consider the difficulties of diagnosing PEI and relate these to the value of treatment for each diagnostic category.

RESULTS AND CONCLUSIONS

Recent studies confirm that patients with chronic pancreatitis receive similar benefit from pancreatic exocrine replacement therapy (PERT) to that established in children with cystic fibrosis. Severe acute pancreatitis is frequently followed by PEI and PERT should be considered for these patients because of their nutritional requirements. Evidence is also becoming stronger for the benefits of PERT in patients with unresectable pancreatic cancer. However there is as yet no clear guide to help identify those patients in the 'unlikely' PEI group who would benefit from PERT. For example, patients with coeliac disease, diabetes mellitus, irritable bowel syndrome and weight loss in the elderly may occasionally be given a trial of PERT, but determining its effectiveness will be difficult. The starting dose of PERT should be from 25,000-40,000 IU lipase taken with food. This may need to be titrated up and there may be a need for proton pump inhibitors in some patients to improve efficacy.

Clinical skin examination outcomes after a video-based behavioral intervention: analysis from a randomized clinical trial

IMPORTANCE

Older men are at risk of dying of melanoma.

OBJECTIVE

To assess attendance at and clinical outcomes of clinical skin examinations (CSEs) in older men exposed to a video-based behavioral intervention.

DESIGN, SETTING, AND PARTICIPANTS

This was a behavioral randomized clinical trial of a video-based intervention in men aged at least 50 years. Between June 1 and August 31, 2008, men were recruited, completed baseline telephone interviews, and were than randomized to receive either a video-based intervention (n = 469) or brochures only (n = 461; overall response rate, 37.1%) and were again interviewed 7 months later (n = 870; 93.5% retention).

INTERVENTIONS

Video on skin self-examination and skin awareness and written informational materials. The control group received written materials only.

MAIN OUTCOMES AND MEASURES

Participants who reported a CSE were asked for the type of CSE (skin spot, partial body, or whole body), who initiated it, whether the physician noted any suspicious lesions, and, if so, how lesions were managed. Physicians completed a case report form that included the type of CSE, who initiated it, the number of suspicious lesions detected, how lesions were managed (excision, nonsurgical treatment, monitoring, or referral), and pathology reports after lesion excision or biopsy.

RESULTS

Overall, 540 of 870 men (62.1%) self-reported a CSE since receiving intervention materials, and 321 of 540 (59.4%) consented for their physician to provide medical information (received for 266 of 321 [82.9%]). Attendance of any CSE was similar between groups (intervention group, 246 of 436 [56.4%]; control group, 229 of 434 [52.8%]), but men in the intervention group were more likely to self-report a whole-body CSE (154 of 436 [35.3%] vs 118 of 434 [27.2%] for control group; P = .01). Two melanomas, 29 squamous cell carcinomas, and 38 basal cell carcinomas were diagnosed, with a higher proportion of malignant lesions in the intervention group (60.0% vs 40.0% for controls; P = .03). Baseline attitudes, behaviors, and skin cancer history were associated with higher odds of CSE and skin cancer diagnosis.

CONCLUSIONS AND RELEVANCE

A video-based intervention may increase whole-body CSE and skin cancer diagnosis in older men.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12608000384358.

What is the optimal level of vitamin D? - separating the evidence from the rhetoric

BACKGROUND

Vitamin D deficiency is thought to be common in Australia. It is unclear when vitamin D supplementation should be prescribed.

OBJECTIVE

We assess the evidence that guides clinical decision-making on supplementation with vitamin D following a vitamin D test result.

DISCUSSION

Vitamin D assays are inconsistent and inaccurate and there is weak evidence around the level of 25-hydroxyvitamin D (25(OH)D) that is optimal. Evidence of links between vitamin D deficiency and disease come from observational studies and there is little support from randomised controlled trials of vitamin D supplementation. Where there is evidence of a link, increased risk is largely confined to very low 25(OH)D levels, with minimal health gains for 25(OH)D levels greater than 50 nmol/L. New evidence indicates that both high and low 25(OH)D levels may be associated with increased health risks. Taken together these considerations present a considerable challenge to clinical decision-making around treatment on the basis of 25(OH)D levels.

Association between ambient ultraviolet radiation and risk of epithelial ovarian cancer

Evidence is accumulating to suggest that higher exposure to solar ultraviolet radiation (UVR) is associated with decreased risk of internal cancers, but data for ovarian cancer are unclear. We aimed to examine the association between lifetime ambient UVR and ovarian cancer in a population-based-case-control study. The study included women aged 18 to 79 years with a new diagnosis of invasive (n = 1,215) or borderline (n = 285) epithelial ovarian cancer identified through a network of clinics and state cancer registries throughout Australia. Controls (n = 1,459), frequency matched to cases by age (5-year groups) and state of residence, were randomly selected from the National Electoral Roll. We asked participants to report where they had lived at different periods of their life and assigned an estimate of UVR using data from NASA's Total Ozone Mapping Spectrometer database (1997-2003). We estimated the association between ambient UVR and risk of ovarian cancer using conditional logistic regression adjusted for potential confounders. Women in the highest third of average daily ambient UVR over their lifetime were at significantly lower risk of all epithelial ovarian cancers than those in the lowest third [OR, 0.70; 95% confidence interval (CI), 0.56-0.88]. The inverse association was stronger for borderline tumors (0.47, 0.31-0.71) than invasive tumors (0.78, 0.61-1.00). The effect sizes for overall and borderline tumors were unchanged after adjusting for confounders, whereas the inverse association for invasive tumors was attenuated. These data suggest that exposure to ambient UVR may reduce the risk of ovarian cancer.

Non-ocular tumours following retinoblastoma in Great Britain 1951 to 2004

BACKGROUND

Retinoblastoma occurs in both a heritable and a non-heritable form. In the heritable form, there is a predisposition to the development of non-ocular tumours.

OBJECTIVES

To identify the types of non-ocular tumour occurring in retinoblastoma survivors and to produce estimates of risk for these tumours.

METHODS

We carried out a cohort study that included 1927 cases of retinoblastoma diagnosed in Great Britain between 1951 and 2004. Cases were ascertained through the National Registry of Childhood Tumours and followed up for the occurrence of non-ocular tumours using the routine notification system based on the National Health Service Central Registers in Britain.

RESULTS

Of the 1927 cases, 809 were known to have the heritable form of the disease and 1118 assumed to have the non-heritable form. 102 of the heritable and 13 of those classified as non-heritable developed a non-ocular tumour. The cumulative risk of developing such a tumour 50 years after retinoblastoma diagnosis was 48.3% (95% confidence interval: 38.1 to 59.7%) in the heritable and 4.9% (1.9 to 12.4%) in the non-heritable cases. The main categories of non-ocular tumours observed in the heritable cases were soft-tissue sarcomas (36 of which 21 were leiomyosarcoma), osteosarcoma (32), carcinoma (13), brain and central nervous system tumours (10), melanoma (9), leukaemia (4) and others (4). There were a total of 108 non-ocular tumours in 102 cases.

CONCLUSIONS

There is a high risk of non-ocular tumours occurring in survivors of heritable retinoblastoma. These results have important implications for the clinical follow-up and counselling of survivors.

Do users of the intrauterine system (Mirena) have different genital symptoms and vaginal flora than users of the intrauterine contraceptive device?

The copper intrauterine contraceptive device (IUCD) is strongly associated with bacterial vaginosis (BV). Hormonal influences may play a role in the control of vaginal flora. It is unclear whether use of the progesterone-incorporated intrauterine system (IUS; Mirena) is associated with abnormal vaginal flora or genital symptoms. One hundred and seventy-two women were assessed for symptoms and abnormal vaginal flora prior to and at intervals after insertion of either a copper IUCD or an IUS. Women were significantly more likely to have developed an abnormal vaginal discharge 4-6 weeks after insertion of an IUCD compared with an IUS (27% cf. 14%, P = 0.04), although this trend was not significant six months postinsertion. More women with an IUCD developed BV compared with an IUS at 4-6 weeks and six months. However, there were insufficient numbers of women with BV to demonstrate any significant difference between the vaginal flora of the two groups.

Prevalence and multiplicity of cutaneous beta papilloma viruses in plucked hairs depend on cellular DNA input

In view of the low loads of beta human papillomaviruses in skin samples, amounts of cellular DNA used in qualitative PCR may become limiting for virus detection and introduce variations in prevalence and multiplicity. This issue was explored within the context of a multicentre study and increasing prevalence and multiplicity was found with increasing input amounts of cellular DNA extracted from hair bulbs. To improve the quality and comparability between different epidemiologic studies ideally equal amounts of cellular DNA should be employed. When cellular DNA input varies this should be clearly taken into account in assessing viral prevalence and multiplicity.

Prevalence and associated factors of betapapillomavirus infections in individuals without cutaneous squamous cell carcinoma

Betapapillomavirus (betaPV) infections are often associated with squamous-cell carcinoma (SCC) and the prevalence of betaPV infections in (immunosuppressed) SCC patients is known to be high. The distribution and possible associated factors of betaPV infections in the general population, however, are largely unknown. To address this issue, betaPV infection was studied in 1405 SCC-free immunocompetent (n=845) and immunosuppressed (n=560) individuals from six countries of different latitudes. A standard study protocol was used to obtain information about age, sex, UV-irradiation and skin type, and from all participants eyebrow hairs were collected for detection and genotyping of 25 established betaPV types using the PM-PCR reverse hybridization assay (RHA) method. The frequency of betaPV-positive participants ranged from 84 to 91 % in the immunocompetent population with HPV23 as the most prevalent type, and from 81 to 98 % in the immunosuppressed population with HPV23 as the most or the second most prevalent type. The median number of infecting betaPV types ranged from four to six in the immunocompetent and from three to six in the immunosuppressed population. Increasing age in the immunocompetent participants and (duration of) immunosuppression in the immunosuppressed patients were associated with betaPV infection. In both groups, sex, skin phototype, sunburns and sun-exposure were not consistently associated with betaPV infection. This study demonstrates that betaPV infections are also highly prevalent in SCC-free individuals, with similar HPV types prevailing in both immunocompetent and immunosuppressed persons. Age and (duration of) immunosuppression were identified as betaPV infection-associated factors, whereas characteristics related to sun exposure and skin type were not.

Antibody responses to 26 skin human papillomavirus types in the Netherlands, Italy and Australia

Solar UV radiation is the main risk factor for cutaneous squamous cell carcinoma (SCC), but infections with skin human papillomavirus (HPV) types have also been linked to the development of SCC. Little is known about the natural history of these infections and whether the seroprevalence of skin HPV types is affected by ambient or individual levels of sun exposure. This study investigated this by analysing sera for antibodies to 26 skin HPV types from five phylogenetic genera obtained from 807 healthy individuals from the Netherlands, Italy and Australia, countries with strong differences in sunlight intensity. Overall HPV seroprevalence was similar across the three countries (50-57 % for beta-HPV types, 40-48 % for gamma-HPV types), and the most frequent beta-HPV and gamma-HPV types were the same in all countries. The highest seroprevalences for 24 of the 26 skin HPV types were observed in Italy (14 types) and Australia (ten types). Seroprevalence among men was generally higher than among women, and the male sex was significantly associated with both beta-HPV [odds ratio (OR) 2.81, 95 % confidence interval (CI) 1.64-4.82] and gamma-HPV (OR 2.42, 95 % CI 1.40-4.18) antibodies in Australia. The only measure of sun sensitivity or UV exposure significantly associated with skin HPV seroprevalence was found for weekend sun exposure in Australia and beta-HPV antibodies. It was concluded that type spectra and HPV seroprevalence are similar in countries with different sunlight intensity, and that levels of UV exposure do not play a strong role in the development of skin HPV antibodies in this study population.

Association between endogenous plasma hormone concentrations and fracture risk in men and women: the EPIC-Oxford prospective cohort study

Sex steroids have an important role in bone health, however previous studies on fracture risk have been carried out in older populations. The EPIC-Oxford study is a prospective cohort of men and women living in the UK. Five years after recruitment, participants self-reported previous fractures. Sex steroid concentrations (plasma estradiol, testosterone and sex hormone binding globulin) were measured in 436 cases (155 men, 46 premenopausal women and 235 postmenopausal women) with an incident fracture and 868 matched controls. Fracture risk was inversely related to concentrations of estradiol among men (RR for a doubling of estradiol 0.35, 95% CI 0.44-0.96) but there was no association between fracture risk and testosterone levels. There were no clear associations between fracture risk and hormone levels among postmenopausal women, however there was suggestion of an inverse association for both estradiol and testosterone as the RR in the highest compared with the lowest tertile for estradiol was 0.74 (95% CI 0.46, 1.18) and testosterone was 0.75 (95% CI 0.49, 1.16). Among premenopausal women fracture risk was inversely associated with levels of testosterone (RR for doubling of testosterone 0.46, 95% CI 0.26-0.81), with no association between estradiol and fracture risk. SHBG was not associated with risk of fracture among either men or women. In summary, this study finds evidence of an inverse association between endogenous estradiol and risk of fracture in men, and between endogenous testosterone and risk of fracture in premenopausal women but no clear associations among postmenopausal women.

Who attends primary care services prior to attendance at genitourinary services and what level of care have they received?

OBJECTIVE

To determine the proportion of patients initially attending primary care services and describe the care received prior to attending genitourinary medicine (GUM) clinics.

METHOD

A cross-sectional survey of 1000 new patients attending GUM services in Cornwall between June and December 2006. Patients were asked during consultation whether they had attended primary care before coming and what examination, investigation and management had been carried out there.

RESULTS

35% (348/1000) of patients had attended primary care initially. Genital examination had been carried out in primary care on 60% (111/185) female and 58% (93/159) male patients (p = 0.78). Chlamydia testing had been carried out in 27% (46/171) female and 6% (8/139) male patients (p<0.005). 33% (100/301) patients seen in primary care had been offered treatment. 74% (68/92) patients with genital warts had been correctly diagnosed in primary care and 9% (8/92) of these offered treatment.

CONCLUSIONS

The majority of these patients, including those given a diagnosis and/or offered treatment in primary care, had not had a chlamydia test or any other investigations. With the potential "fall out" of patients between primary care and GUM services, this may represent a missed opportunity to detect and appropriately manage sexually transmitted infections.

Association between plasma 25-hydroxyvitamin D levels and fracture risk: the EPIC-Oxford study

The importance of vitamin D for bone health is well established, but few data exist on the relation between plasma levels of 25-hydroxyvitamin D and risk of fracture. The authors examined this association within the EPIC-Oxford (European Prospective Investigation into Cancer and Nutrition-Oxford cohort) study of men and women in the United Kingdom (1993-1999). Five years after recruitment, participants completed a follow-up questionnaire where fracture incidence was self-reported. Plasma 25-hydroxyvitamin D concentration was measured in 730 incident fracture cases and 1,445 matched controls. There was a clear association between plasma 25-hydroxyvitamin D concentration and month of blood draw, the highest values being during the summer months. Among women, there were significant relations between 25-hydroxyvitamin D levels and age, body mass index, marital status, use of hormone therapy, physical activity, diet group, dietary intake of vitamin D, and alcohol. Similar relations were seen among men, although often they were nonsignificant because of smaller numbers. There was no evidence of an association between plasma 25-hydroxyvitamin D and fracture risk for men or women; the relative risks associated with a doubling of plasma 25-hydroxyvitamin D were 1.15 (95% confidence interval: 0.82, 1.61) and 0.95 (95% confidence interval: 0.80, 1.13), respectively. These results were not affected by adjustment for potential confounders and were consistent across a number of subgroups.

Sun protection and low levels of vitamin D: are people concerned?

OBJECTIVE

Recent reports on the association between low serum vitamin D and increased risk of cancer raised concerns about possible adverse effects of primary prevention strategies for skin cancer. To evaluate if these reports may influence peoples' sun protective behavior, knowledge, and attitudes to the impact of sun protection on vitamin D.

METHODS

Within a population-based survey in Queensland, Australia (5,611 participants, mean age 50.7 years (range 20-75); 48.2% men), agreement with the statement that sun protection may result in not having enough vitamin D as well as factors associated with agreement were assessed.

RESULTS

Overall, 837 (15.0%) participants agreed that sun protection may result in not having enough vitamin D, 2,163 (38.7%) neither agreed nor disagreed, and 2,591 (46.3%) disagreed with this statement. Factors associated with agreement included older age, darker skin color, and attempt to develop a suntan within the past year.

CONCLUSION

These results suggest that future sun protection campaigns may need to address the issue of vitamin D and present ways to achieve sufficient vitamin D levels without increasing sun exposure at least in countries with high UV radiation throughout the year.

Sun-Related Factors, Betapapillomavirus, and Actinic Keratoses

OBJECTIVE

To examine prospectively the relationship among sun exposure, Betapapillomavirus, and development of actinic keratoses.

DESIGN

Prospective, community-based cohort study.

SETTING

Township of Nambour in Southeast Queensland, Australia.

PARTICIPANTS

A total of 291 randomly selected adults aged 36 to 86 years with the presence or absence of Betapapillomavirus DNA in eyebrow hair follicle cells known at baseline in August 1996 and with subsequently documented sun exposure histories.

MAIN OUTCOME MEASURES

Prevalence of actinic keratoses in March 2003 after 7 years of follow-up.

RESULTS

Beyond the known determinants of multiple actinic keratoses, namely, advanced age, male sex, fair skin, and lifetime occupational sun exposure, Betapapillomavirus infection was associated with having more than 10 actinic keratoses (odds ratio, 1.8; 95% confidence interval, 0.7-4.4). However, Betapapillomavirus positivity led to a significant 13-fold increase in the risk of actinic keratoses among those 60 years or older, a nearly 6-fold increase in risk when combined with fair skin color, and a doubling in risk of actinic keratoses when combined with high sun exposure, recent or cumulative, compared with those who had neither Betapapillomavirus infection nor the respective risk factor of interest.

CONCLUSIONS

Although the presence of Betapapillomavirus DNA in eyebrow hair follicle cells had only a small independent association with actinic keratoses, Betapapillomavirus infection in combination with key risk factors increased the risk of actinic keratoses, which is consistent with a potentiation by Betapapillomavirus of the effect of established causal factors.

Keratotic skin lesions and other risk factors are associated with skin cancer in organ-transplant recipients: a case-control study in The Netherlands, United Kingdom, Germany, France, and Italy

This study examines the association of keratotic skin lesions with the development of skin cancer in 915 solid organ-transplant recipients in five European countries. In a hospital-based case-control study, cases with squamous- and basal-cell carcinoma were compared with controls without skin cancer. Questionnaires, scrutiny of medical charts, and skin examination were delivered according to a standardized protocol. Keratotic skin lesions and viral warts were counted on different body sites. Keratotic skin lesions were strongly associated with an increased risk of squamous-cell carcinoma, with adjusted odds ratios of 4.1 (2.4;7.0) and 12.1 (6.1;24) for 1-49 and 50 and more keratotic skin lesions compared with no lesions, respectively. Keratotic skin lesions were also associated with basal-cell carcinoma with adjusted odds ratios of 2.9 (1.7;4.9) and 4.0 (1.7;9.2) for 1-49 and 50 and more lesions, respectively. Lighter skin types and painful sunburns were also significantly associated with an increased risk of squamous- and basal-cell carcinoma. Keratotic skin lesions are strongly associated with skin cancer and are, thus, an important clinical criterion for identifying those organ-transplant recipients at an increased risk of skin cancers who should be offered more intensive skin surveillance.

Markers of cutaneous human papillomavirus infection in individuals with tumor-free skin, actinic keratoses, and squamous cell carcinoma

Separately, actinic keratosis (AK) and cutaneous squamous cell carcinoma (SCC) have been associated with cutaneous human papillomavirus (HPV) infections. To further explore the association between HPV infection and SCC development, we determined markers of cutaneous HPV infection within a single population in persons with precursor lesions (AK), cancerous lesions (SCC), and without. Serum and plucked eyebrow hairs were collected from 57 tumor-free controls, 126 AK, and 64 SCC cases. Presence of HPV L1 and E6 seroreactivity and viral DNA were determined for HPV types 5, 8, 15, 16, 20, 24, and 38. Significant positive associations with increasing severity of the lesions (controls, AK, and SCC, respectively) were observed for overall HPV L1 seropositivity (13%, 26%, and 37%) and for HPV8 (4%, 17%, and 30%). In parallel, the proportion of L1 seropositive individuals against multiple HPV types increased from 14% to 39% and 45%. The overall E6 seroreactivity, however, tended to decline with AK and SCC, especially for HPV8 (21%, 11%, and 2%). HPV DNA positivity was most prevalent in the AK cases (54%) compared with the SCC cases (44%) and the tumor-free controls (40%). Among all participants, there was a positive trend between overall HPV DNA positivity and L1 seropositivity, but not E6 seropositivity. Taken together, our data suggest that cutaneous HPV infections accompanied by detectable HPV DNA in eyebrow hairs and HPV L1 seropositivity, but not E6 seropositivity, are associated with an increased risk of AK and SCC.

Apolipoproteins as Predictors of Ischaemic Stroke in Patients with a Previous Transient Ischaemic Attack

BACKGROUND

Weak associations between total and LDL cholesterol and ischaemic stroke compared with coronary heart disease (CHD) are at odds with the similar effectiveness of statin drugs in preventing ischaemic stroke and CHD, suggesting that other lipid sub-fractions that are affected by statins might be better predictors of ischaemic stroke. Apolipoprotein B levels are reduced by statins and are a stronger predictor of CHD than total and LDL cholesterol in patients both on and off statins. However, there are very few published data on apolipoproteins and stroke risk and no studies in patients with previous transient ischaemic attack (TIA).

METHODS

We performed a prospective cohort study of the associations of baseline total cholesterol, LDL, HDL, apolipoproteins A1 and B (apo A1; apo B) and risk of ischaemic stroke in 261 patients with previous TIA. Cox proportional hazards models were used to determine crude and multivariate-adjusted hazard ratios (HR) above versus below median values at 10-years follow-up.

RESULTS

The apo B/apo A1 ratio was the strongest independent predictor of ischaemic stroke (HR=2.94, 95% CI 1.43-5.88, p=0.003) followed by apo B (HR=2.26, 95% CI 1.16-4.38, p=0.02). The associations between total cholesterol, LDL, HDL, LDL/HDL ratio and apo A1 and ischaemic stroke risk did not reach statistical significance.

CONCLUSIONS

Apo B and the apo B/apo A1 ratio are predictive of ischaemic stroke in patients with previous TIA. Further studies are required to determine whether the prognostic value of apolipoprotein levels is maintained in patients on statins.

Nonsteroidal anti-inflammatory drugs and the risk of actinic keratoses and squamous cell cancers of the skin

BACKGROUND

Although animal studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, may protect against cutaneous squamous cell carcinoma (SCC) and actinic keratoses (AKs), possible effects on keratinocytic cancers in humans are unknown.

OBJECTIVE

We sought to examine the relationship between ingestion of NSAIDs and the risk of SCC and AKs in humans.

METHODS

We conducted a case-control study nested within a community-based cohort of 1621 people in southern Queensland, Australia. Eighty-six persons with SCC were compared with 187 age- and sex-matched control subjects randomly selected from within the cohort. NSAID use was captured through face-to-face interviews with study participants, supplemented by color photographs of product packaging. We defined regular use of NSAIDs as consumption of at least two tablets per week (low frequency) or at least 8 tablets per week (high frequency) for at least 1 year. AKs were counted on the face, ears, right hand, and right forearm by a single physician.

RESULTS

Patients with SCC were significantly less likely than control subjects to have used any NSAIDs 8 or more times per week for more than 1 year (multivariate odds ratio [OR] 0.07, 95% confidence interval [CI] 0.01-0.71) and to have used full-dose NSAIDs 2 or more times per week for more than 5 years (OR, 0.20; 95% CI, 0.04-0. 96). Among participants without SCC, current regular users of NSAIDs (> or =2 times per week) had significantly lower counts of AKs than nonusers (rate ratio [RR], 0.52; 95% CI, 0.30-0.91).

LIMITATIONS

Estimates of NSAID use were based on self-reported data. Statistical power to detect associations was limited by the number of cases with SCC.

CONCLUSION

Regular users of NSAIDs appear to have lower risks of SCC and lower counts of AKs than nonusers.

Validating the functional capacity index: a comparison of predicted versus observed total body scores

BACKGROUND

The Functional Capacity Index (FCI) was designed to predict physical function 12 months after injury. We report a validation study of the FCI.

METHODS

This was a consecutive case series registered in the Queensland Trauma Registry who consented to the prospective 12-month telephone-administered follow-up study. FCI scores measured at 12 months were compared with those originally predicted.

RESULTS

Complete Abbreviated Injury Scale score information was available for 617 individuals, of whom 587 (95%) could be assigned at least one FCI score (range, 1-17). Agreement between the largest predicted FCI and observed FCI score was poor (kappa = 0.05; 95% confidence interval, 0.00-0.10) and explained only 1% of the variability in observed FCI. Using an encompassing model that included all FCI assignments, agreement remained poor (kappa = 0.05; 95% confidence interval, -0.02-0.12), and the model explained only 9% of the variability in observed FCI.

CONCLUSION

The predicted functional capacity poorly agrees with actual functional outcomes. Further research should consider including other (noninjury) explanatory factors in predicting FCI at 12 months.

Statin precipitated lactic acidosis?

An 82 year old woman was admitted with worsening dyspnoea. Arterial blood gases were taken on air and revealed a pH of 7.39, with a partial pressure of CO2 (pCO2) of 1.2 kPa, pO2 of 19.3 kPa, HCO3 of 13.8 mmol/litre, and base excess of -16.3 mmol/litre: a compensated metabolic acidosis with hyperventilation induced hypocapnia, which is known to be a feature of lactic acidosis. There was also an increased anion gap ((Na140 + K4.0) - (Cl 106 + HCO3 13.8) = 24.2 mEq/litre (reference range, 7-16)), consistent with unmeasured cation. Lactate was measured and found to be raised at 3.33 mmol/litre (reference range, 0.9-1.7). After exclusion of common causes of lactic acidosis Atorvastatin was stopped and her acid-base balance returned to normal. Subsequently, thiamine was also shown to be deficient. The acidosis was thought to have been the result of a mitochondrial defect caused by a deficiency of two cofactors, namely: ubiquinone (as a result of inhibition by statin) and thiamine (as a result of dietary deficiency).

The effect of skin examination surveys on the incidence of basal cell carcinoma in a Queensland community sample: a 10-year longitudinal study

Skin cancers pose a significant public health problem in high-risk populations. We have prospectively monitored basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) incidence in a Queensland community over a 10-y period by recording newly treated lesions, supplemented by skin examination surveys. Age-standardized incidence rates of people with new histologically confirmed BCC were 2787 per 100,000 person-years at risk (pyar) among men and 1567 per 100,000 pyar among women, and corresponding tumor rates were 5821 per 100,000 pyar and 2733 per 100,000 pyar, respectively. Incidence rates for men with new SCC were 944 per 100,000 pyar and for women 675 per 100,000 pyar; tumor rates were 1754 per 100,000 pyar and 846 per 100,000 pyar, respectively. Incidence rates of BCC tumors but not SCC tumors varied noticeably according to method of surveillance, with BCC incidence rates based on skin examination surveys around three times higher than background treatment rates. This was mostly due to an increase in diagnosis of new BCC on sites other than the head and neck, arms, and hands associated with skin examination surveys and little to do with advancing the time of diagnosis of BCC on these sites as seen by a return to background rates following the examination surveys. We conclude that BCC that might otherwise go unreported are detected during skin examination surveys and thus that such skin cancer screening can influence the apparent burden of skin cancer.

A randomized controlled trial to assess sunscreen application and beta carotene supplementation in the prevention of solar keratoses

BACKGROUND

Solar keratoses (SKs) are among the strongest determinants of skin cancer, but little is known about the success of measures to control these common skin tumors.

OBJECTIVE

To determine whether daily sunscreen application and/or beta carotene supplementation retards the rate of occurrence of SKs in adults in the medium term.

DESIGN

Randomized controlled trial conducted between February 1992 and August 1996.

SETTING

General community of the subtropical township of Nambour, Australia (latitude, 26 degrees south).

PARTICIPANTS

A total of 1621 adults aged 25 to 74 years. Interventions Participants were randomized to daily use of sunscreen (application of a high-protection sunscreen to their head, neck, arms, and hands every morning) or application of sunscreen at their usual discretionary rate. They were also randomly assigned to take either one 30-mg tablet of beta carotene or one placebo tablet each day.

MAIN OUTCOME MEASURE

Change in the prevalent number of SKs in the intervention group relative to change in the control group.

RESULTS

The ratio of SK counts in 1994 relative to 1992 was lower in people randomized to daily sunscreen use (1.20; 95% confidence interval, 1.04-1.39) than in those randomized to discretionary sunscreen use (1.57; 95% confidence interval, 1.35-1.84). This 24% reduction is equivalent to the prevention of an average of 1 additional SK per person over that time. A reduction in the rate of change of SK prevalence was also seen in the sunscreen intervention group relative to the discretionary sunscreen group between 1994 and 1996, but it was not significant. No effect on the rate of change of prevalent SK counts was seen among those taking beta carotene supplements relative to those taking placebo tablets.

CONCLUSIONS

Daily application of sunscreen retarded the rate of SK acquisition among adults in a subtropical environment, while a beta carotene supplementation of 30 mg/d had no influence on the occurrence of SKs.

Interrater reliability of injury coding in the Queensland Trauma Registry

BACKGROUND

The capacity to accurately code injury event details and use the Abbreviated Injury Scale and Injury Severity Score to group injuries according to severity, underpins the audit and review activities of the trauma registries throughout the world. In the interests of transparency and benchmarking between registries, we aimed to assess the interrater reliability of coding in the Queensland Trauma Registry.

METHODS

One hundred and twenty injury cases were randomly selected from the Queensland Trauma Registry database, stratified by hospital, severity and the coder who originally coded the chart. Cases were then recoded by six coders employed by the Queensland Trauma Registry. Coding was carried out by all raters simultaneously and independently.

RESULTS

Interrater agreement between coders was high for external cause, intent, and place of injury with kappa scores for all interrater pairs being greater than 0.80, 0.58 and 0.44. Agreement between the six raters for Injury Severity Score was found to be very high (intraclass correlation coefficient of 0.9).

CONCLUSIONS

The accuracy of coding in the Queensland Trauma Registry is sufficiently high to ensure that quality data are available for research, audit and review.

Application patterns among participants randomized to daily sunscreen use in a skin cancer prevention trial

BACKGROUND

Despite many investigations of sunscreen use, there have been few among adults in the community at large. Better understanding of sunscreen application patterns will lead to more strategic skin cancer prevention strategies among sun-exposed populations.

OBJECTIVE

To explore patterns of sunscreen use, particularly the quantity of sunscreen used and the application frequency, among participants in a community-based sunscreen intervention.

DESIGN

Follow-up of patterns of sunscreen use over 4.5 years.

SETTING

Nambour, a subtropical town in Queensland, Australia.

PARTICIPANTS

People drawn randomly from the electoral register who were later randomized as part of a skin cancer prevention trial.

INTERVENTIONS

Daily application of a standard sun protection factor 15+ broad-spectrum retail sunscreen to the head and neck, arms, and hands.

OUTCOME MEASURES

Frequency of application of sunscreen, weight of sunscreen applied, and quantity applied per unit area of skin.

RESULTS

Fifty-six percent of participants reported applying sunscreen on at least 5 days per week, with 27% using sunscreen infrequently on 2 or fewer days per week. The median daily amount of sunscreen applied averaged over the duration of the trial was 1.5 g/d (range, 0-7.4 g/d). The median quantity of sunscreen applied was 0.79 mg/cm(2), which was less than half the amount needed to achieve the labeled sun protection factor.

CONCLUSIONS

It is possible to implement the daily application of sunscreen in sun-exposed populations, although protection would be increased if the quantity of sunscreen applied were greater.

Appropriate indicators for injury control?

Indicators are valuable tools used to measure progress towards a desired health outcome. Increased awareness of the public health burden due to injury has lead to a concomitant interest in monitoring the impact of national initiatives that aim to reduce the size of the burden. Several injury indicators have now been proposed. This study examines the ability of each of the suggested indicators to reflect the nature and extent of the burden of non-fatal injury. A criterion validity, population-based, prospective cohort study was conducted in Brisbane, a sub-tropical Metropolitan City on the eastern seaboard of Australia, over a 12-month period between 1 January and 31 December 1998. Neither the presence of a long bone fracture nor the need for hospitalisation for 4 or more days were sensitive or specific indicators for 'serious' or major injury as defined by the 'Gold Standard' Injury Severity Score (ISS). Subsequent analysis, using other public health outcome measures demonstrated that the major component of the illness burden of injury was in fact due to 'minor' not serious injury. However, the suggested indicators demonstrated low sensitivity and specificity for these outcomes as well. The results of the study support the need to include at least all hospitalisations in any population-based measure of injury and not attempt to simplify the indicator to a more convenient measure aimed at identifying just those cases of 'serious' injury.

Cognition and survival: an exploration in a large multicentre study of the population aged 65 years and over

BACKGROUND

Understanding the patterns in determinants of survival becomes increasingly important as the population ages. Dementia is known to shorten survival as is impaired cognition. Whether this is a continuous phenomenon and independent of other explanatory variables is less clear.

OBJECTIVES

To examine a population-based dataset in which a measure of cognitive function (Mini-Mental State Examination [MMSE]), self-reported physical health and lifestyle variables were measured at outset, with monitoring for mortality thereafter.

METHODS

The five identical sites of the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) were analysed, with populations in rural Cambridgeshire, Gwynedd, Newcastle, Nottingham and Oxford. Survival curves were modelled and stratified analyses carried out, with physical disease, sociodemographic variables and lifestyle variables as covariates.

RESULTS

There was a strong and consistent reduction in survival probability for each decrement in MMSE. Adjustment for known confounders did not alter this pattern. Social class and education in particular had no additional effect. Self-reported health was the only other associated variable.

CONCLUSION

Cognitive function appears to be a marker of capacity for survival in the UK. Terminal decline can account for some of this. Actuarial survival provided here can give carers and service providers an idea of prognosis at given ages and levels of cognition, and provide baseline data for those planning interventions in similar groups.

Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial

BACKGROUND

The use of sunscreens on the skin can prevent sunburn but whether long-term use can prevent skin cancer is not known. Also, there is evidence that oral betacarotene supplementation lowers skin-cancer rates in animals, but there is limited evidence of its effect in human beings.

METHODS

In a community-based randomised trial with a 2 by 2 factorial design, individuals were assigned to four treatment groups: daily application of a sun protection factor 15-plus sunscreen to the head, neck, arms, and hands, and betacarotene supplementation (30 mg per day); sunscreen plus placebo tablets; betacarotene only; or placebo only. Participants were 1621 residents of Nambour in southeast Queensland, Australia. The endpoints after 4.5 years of follow-up were the incidence of basal-cell and squamous-cell carcinomas both in terms of people treated for newly diagnosed disease and in terms of the numbers of tumours that occurred. Analysis of the effect of sunscreen was based only on skin cancers that developed on sites of daily application. All analyses were by intention to treat.

FINDINGS

1383 participants underwent full skin examination by a dermatologist in the follow-up period. 250 of them developed 758 new skin cancers during the follow-up period. There were no significant differences in the incidence of first new skin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100,000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100,000; rate ratio 0.88 [0.50-1.56]). Similarly, there was no significant difference between the betacarotene and placebo groups in incidence of either cancer (basal-cell carcinoma 3954 vs 3806 per 100,000; 1.04 [0.73-1.27]; squamous-cell carcinoma 1508 vs 1146 per 100,000; 1.35 [0.84-2.19]). In terms of the number of tumours, there was no effect on incidence of basal-cell carcinoma by sunscreen use or by betacarotene but the incidence of squamous-cell carcinoma was significantly lower in the sunscreen group than in the no daily sunscreen group (1115 vs 1832 per 100,000; 0.61 [0.46-0.81]).

INTERPRETATION

There was no harmful effect of daily use of sunscreen in this medium-term study. Cutaneous squamous-cell carcinoma, but not basal-cell carcinoma seems to be amenable to prevention through the routine use of sunscreen by adults for 4.5 years. There was no beneficial or harmful effect on the rates of either type of skin cancer, as a result of betacarotene supplementation.

The shady side of solar protection

OBJECTIVE

To determine the value of shade in protecting humans from solar ultraviolet (UV) radiation.

DESIGN AND SETTING

Measurement with photometers of protection factors for ultraviolet B radiation (UVB) and for total solar radiation for different types of trees and other structures during the summer months (1995-1997) in south-east Queensland. (The protection ratio is the ratio of the intensity of UVB or total solar radiation in direct sunlight to that in shade.)

RESULTS

For summer sun at midday, the mean (SD) UV protection ratio for the shade of trees (n = 65) was 4.21 (1.36) on a horizontal surface and 1.33 (0.30) on a vertical surface. In contrast, the mean (SD) protection ratio for total solar energy (primarily infrared) was much higher (12.1 [1.4]). Trees common in recreational areas in Australia (eucalypts: UV protection ratio, 3.52 [0.79]; Norfolk Island pines: UV protection ratio, 3.72 [0.98]) offered reduced protection compared with trees with more dense foliage (UV protection ratio, 5.48 [1.44]). Over a whole day, measurement of shade by trees and other structures showed that the UV protection ratio was lower in the morning and afternoon. Shade from awnings, buildings and hats gave similar results to those for trees. Both at midday and over a whole day satisfactory protection (UV protection ratio > 15) was obtained only in shade which eliminated exposure to the sky as well as to direct sunlight; for example, in thickly wooded areas and under low, widely overhanging structures.

CONCLUSIONS

Most forms of shade, while useful, offer people insufficient protection from solar UV. A fair-skinned person sheltering under a tree could suffer sunburn after less than one hour. There is a need for appropriate design of structural shade, use of other solar protection measures in conjunction with shade, and research on behavioural responses to shade.

Sun exposure, sunscreen and their effects on epidermal Langerhans cells

This study examined the effects of chronic and current sun exposure on the number of Langerhans cells in epidermal sheets of UV-exposed and unexposed skin of the arms and assessed the effect of sunscreens. Participants were enrolled in a skin cancer prevention trial and had been using sunscreen daily for the previous 3 years. There were significantly fewer Langerhans cells on the exposed (463 cells/mm2) than on the unexposed forearm (528 cells/mm2) (P = 0.0001). High sun exposure in the previous 2 weeks and a history of predominantly outdoor occupations were both associated with a reduced number of Langerhans cells, although age and other biological indicators of chronic exposure were not associated. Sunscreen use was protective against the effects of current but not chronic sun exposure, with a suggestion of a greater effect at higher levels of exposure. Unexpectedly, people with a past history of nonmelanoma skin cancer had more Langerhans cells in both the exposed and the unexposed skin. These results emphasize the need for continued public health education to protect the immune system from the damaging effects of UV radiation.

An animal model for human melanoma

Experimental animal models that are directly relevant to human melanoma are lacking. We propose the Angora goat as a potentially useful field model with experimental potential and to this end have examined the prevalence and site distribution of all skin cancers in 28 Angora goat herds in Queensland, Australia. The prevalence of benign melanocytic lesions (lentigines) and their experimental induction by sunlight were also investigated. Among 1731 goats over 2 years of age, 139 malignant skin tumors were excised from 95 affected animals. The prevalence of squamous cell carcinoma (SCC) was 3.8% and of melanoma, 2.2%. Main site of occurrence of melanoma (83%) was the dorsal surface of the ear; in contrast SCC occurred mostly (84%) on the perineum. Lentigines were darker and more prevalent on the exposed compared with the unexposed surface of the ear in Angoras, analogous to the higher prevalence of nevi on the exposed compared with the less exposed inner surface of the arm in humans. Lentigines, which were also found on the perineum though lighter in color than on the dorsal ear, were absent in young animals under 3 months but were numerous in 1-3 year olds. Furthermore in an experimental substudy eight goats, having one flank repeatedly shorn and the contralateral flank left unshorn, revealed consistently more solar lentigines on the shorn flank (P < 0.05) when both sides were examined after 9 months. Histopathological examination of paired skin biopsies from five of these goats also showed more abundant pigmentation in skin from the exposed, as compared with the unexposed flank. These findings indicate that sunlight induces tumors and lentigines in goats in a highly site-specific manner. The Angora goat model may suggest paradigms for explaining the site differences observed for human melanoma and may also be useful in the future clarification of molecular changes following carcinogenic levels of sun exposure.

Complications of urogynaecological surgery

Operations to correct stress urinary incontinence are common procedures and are performed by both urologists and gynaecologists. Many surgeons, however, have not received subspecialty training. This review is intended to guide the surgeon in the prevention and management of the more common complications that may occur, such as de novo detrusor instability, voiding dysfunction, and the colposuspension syndrome.

CGS 22745: a selective orally active inhibitor of 5-lipoxygenase

CGS 22745, and aralkyl hydroxamic acid, inhibited 5-hydroxyeicosatetraenoic acid (5-HETE) and leukotriene B4 (LTB4) synthesis in guinea pig leukocytes (IC50 = 0.6 microM). The compound did not appreciably affect cyclooxygenase (ram seminal vesicles), 12-lipoxygenase and thromboxane synthase (human platelets) or 15-lipoxygenase (human neutrophils). CGS 22745 inhibited A23187-induced formation of LTB4 in blood (IC50's of 4.3, 0.56 and 3.2 microM for human, dog and rat, respectively). At 1 mg/kg i.v. in dogs, it caused 96% inhibition of A23187-stimulated LTB4 formation ex vivo after 5 min. Its effective biological half-life was greater than 160 min. In dogs at 3 and 10 mg/kg p.o., CGS 22745 inhibited ex vivo A23187-stimulated LTB4 formation at 3 hr by 48% and 97%, respectively. The inhibition persisted up to 6 hr (26% at 3 mg/kg; 49% at 10 mg/kg). CGS 22745 (3, 10 and 30 mg/kg p.o.) inhibited exudate formation, mononuclear cells and PMN accumulation in a dose-dependent manner during the late phase (48 and 72 hr) of carrageenan-induced pleurisy in the rat.