Association between unstable diabetes mellitus and risk of pancreatic cancer.

BACKGROUND: Deterioration of glycaemic control in people with long-standing diabetes mellitus (diabetes) may be a possible indicator of pancreatic cancer. However, the magnitude of the association between diabetes deterioration and pancreatic cancer has received little attention. METHODS: We conducted a matched cohort study, nested within a population-based cohort of Australian women with diabetes. Women with unstable diabetes, defined as a change in medication after a 2-year period of stable medication use, were matched by birth year to those with stable diabetes, in a 1:4 ratio. We used flexible parametric survival models to estimate hazard ratios (HRs) and 95% confidence intervals (CI). RESULTS: We included 134,954 and 539,789 women in the unstable and stable diabetes cohorts, respectively (mean age 68 years). In total, 1,315 pancreatic cancers were diagnosed. Deterioration of stable diabetes was associated with a 2.5-fold increased risk of pancreatic cancer (HR 2.55; 95% CI 2.29-2.85). The risk was particularly high within the first year after diabetes deteriorated. HRs at 3 months, 6 months and 1 year were: 5.76 (95% CI 4.72-7.04); 4.56 (95% CI 3.81-5.46); and 3.33 (95% CI 2.86-3.89), respectively. The risk was no longer significantly different after 7 years. CONCLUSIONS: Deterioration in glycaemic control in people with previously stable diabetes may be an indicator of pancreatic cancer, suggesting investigations of the pancreas may be appropriate. The weaker longer-term (3-7 years) association between diabetes deterioration and pancreatic cancer may indicate that poor glycaemic control can be a risk factor for pancreatic cancer.

Vitamin D supplementation and major cardiovascular events: D-Health randomised controlled trial.

OBJECTIVE: To investigate whether supplementing older adults with monthly doses of vitamin D alters the incidence of major cardiovascular events. DESIGN: Randomised, double blind, placebo controlled trial of monthly vitamin D (the D-Health Trial). Computer generated permuted block randomisation was used to allocate treatments. SETTING: Australia from 2014 to 2020. PARTICIPANTS: 21 315 participants aged 60-84 years at enrolment. Exclusion criteria were self-reported hypercalcaemia, hyperparathyroidism, kidney stones, osteomalacia, sarcoidosis, taking >500 IU/day supplemental vitamin D, or unable to give consent because of language or cognitive impairment. INTERVENTION: 60 000 IU/month vitamin D3 (n=10 662) or placebo (n=10 653) taken orally for up to five years. 16 882 participants completed the intervention period: placebo 8270 (77.6%); vitamin D 8552 (80.2%). MAIN OUTCOME MEASURES: The main outcome for this analysis was the occurrence of a major cardiovascular event, including myocardial infarction, stroke, and coronary revascularisation, determined through linkage with administrative datasets. Each event was analysed separately as secondary outcomes. Flexible parametric survival models were used to estimate hazard ratios and 95% confidence intervals. RESULTS: 21 302 people were included in the analysis. The median intervention period was five years. 1336 participants experienced a major cardiovascular event (placebo 699 (6.6%); vitamin D 637 (6.0%)). The rate of major cardiovascular events was lower in the vitamin D group than in the placebo group (hazard ratio 0.91, 95% confidence interval 0.81 to 1.01), especially among those who were taking cardiovascular drugs at baseline (0.84, 0.74 to 0.97; P for interaction=0.12), although the P value for interaction was not significant (<0.05). Overall, the difference in standardised cause specific cumulative incidence at five years was -5.8 events per 1000 participants (95% confidence interval -12.2 to 0.5 per 1000 participants), resulting in a number needed to treat to avoid one major cardiovascular event of 172. The rate of myocardial infarction (hazard ratio 0.81, 95% confidence interval 0.67 to 0.98) and coronary revascularisation (0.89, 0.78 to 1.01) was lower in the vitamin D group, but there was no difference in the rate of stroke (0.99, 0.80 to 1.23). CONCLUSIONS: Vitamin D supplementation might reduce the incidence of major cardiovascular events, although the absolute risk difference was small and the confidence interval was consistent with a null finding. These findings could prompt further evaluation of the role of vitamin D supplementation, particularly in people taking drugs for prevention or treatment of cardiovascular disease. TRIAL REGISTRATION: ACTRN12613000743763.

Vitamin D and Sun Exposure: A Community Survey in Australia.

Sun exposure carries both harms and benefits. Exposing the skin to the sun is the main modifiable cause of skin cancers, which exert a considerable health and economic burden in Australia. The most well-established benefit of exposure to ultraviolet (UV) radiation is vitamin D production. Australia has the highest incidence of skin cancer in the world but, despite the high ambient UV radiation, approximately one quarter of the population is estimated to be vitamin D deficient. Balancing the risks and benefits is challenging and requires effective communication. We sought to provide a snapshot of public knowledge and attitudes regarding sun exposure and vitamin D and to examine the associations between these factors and sun protective behaviors. In 2020 we administered an online survey; 4824 participants with self-reported fair or medium skin color were included in this analysis. Only 25% and 34% of participants were able to identify the amount of time outdoors needed to maintain adequate vitamin D status in summer and winter, respectively and 25% were concerned that sunscreen use inhibits vitamin D synthesis. This lack of knowledge was associated with suboptimal sun protection practices. Public education is warranted to prevent over-exposure, while supporting natural vitamin D production.

The effect of screening on melanoma incidence and biopsy rates.

BACKGROUND: Cutaneous melanomas are common cancers in white-skinned populations, and early detection is promoted as a means of reducing morbidity and mortality. There is concern that increased skin screening is leading to overdiagnosis of indolent melanomas with low risk of lethality. The extent of melanoma overdiagnosis associated with screening is unknown. OBJECTIVES: To estimate possible overdiagnosis by comparing subsequent melanoma incidence and biopsy rates among people subjected to skin screening those who were not. METHODS: We recruited 43 762 residents of Queensland, Australia, aged 40-69 years, with no prior history of melanoma, selected at random from a population register in 2010. At baseline, participants completed a comprehensive melanoma risk factor survey and were asked if their skin had been examined by a doctor in the 3 years prior to baseline. We calculated incidence and relative risk of histologically confirmed melanoma (invasive and in situ) in years 2-7 of follow-up, obtained through linkage to the cancer registry. In secondary analyses, we measured biopsy rates in years 2-6 of follow-up. We used propensity score analysis to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). RESULTS: In total, 28 155 participants underwent skin screening prior to baseline. We observed 967 first-incident melanomas (381 invasive) during 197 191 person-years of follow-up. Those screened had higher rates of melanoma (aHR 1·29, 95% CI 1·02-1·63) and subsequent skin biopses (aHR 1·85, 95% CI 1·69-2·04) than unscreened participants. The higher risk associated with skin screening was evident for in situ melanoma (aHR 1·45, 95% CI 1·09-1·92) but not invasive melanoma (aHR 1·05, 95% CI 0·72-1·54). In secondary analyses, where screening was defined as having a skin biopsy in the first year after baseline, we observed significantly increased risks of melanoma (aHR 1·53, 95% CI 1·23-1·89) and subsequent biopsies (aHR 2·64, 95% CI 2·46-2·84) relative to those who did not have a biopsy. CONCLUSIONS: People who undergo skin screening subsequently experience higher rates of biopsies and melanoma (especially in situ melanoma), even after adjusting for all known risk factors, consistent with overdiagnosis. What is already known about this topic? Cutaneous melanomas are common cancers in white-skinned populations for which early detection is promoted as a means of reducing morbidity and mortality. There is concern that increased surveillance is leading to the overdiagnosis of indolent melanomas that are not destined to be lethal. The extent of melanoma overdiagnosis associated with surveillance is not known. What does this study add? People subjected to skin examinations by a doctor or who undergo skin biopsies subsequently have higher numbers of biopsies and higher rates of melanoma than people not subjected to either, even after adjusting for all known risk factors. These findings suggest that heightened surveillance leads to a proportion of melanomas being diagnosed that otherwise may not have come to clinical attention.

Assessment of Incidence Rate and Risk Factors for Keratoacanthoma Among Residents of Queensland, Australia.

Importance: Keratoacanthoma (KA) is a common and generally benign keratinocyte skin tumor. Reports of the incidence rates of KA are scant. In addition, the risk factors for KA are not well understood, although associations with UV radiation exposure and older age have been described. Objective: To investigate the incidence rate of KA and the risk factors for developing KA. Design, Setting, and Participants: The study included data from 40 438 of 193 344 randomly selected residents of Queensland, Australia, who participated in the QSkin Sun and Health (QSkin) prospective population-based cohort study. All participants completed a baseline survey between 2010 and 2011 and were ages 40 to 69 years at baseline. Histopathologic reports of KA were prospectively collected until June 30, 2014, through data linkage with pathologic records. Cox proportional hazards models were used to identify risk factors associated with KA while controlling for potential confounding variables. Data were analyzed from January 2 to April 8, 2020. Exposures: Demographic characteristics, phenotypes, UV radiation exposure, medical history, and lifestyle. Results: Among 40 438 participants (mean [SD] age, 56 [8] years; 18 240 men [45.1%]), 596 individuals (mean [SD] age, 62 [6] years; 349 men [58.6%]) developed 776 KA tumors during a median follow-up period of 3.0 years (interquartile range, 2.8-3.3 years). The person-based age-standardized incidence rate for KA in the age-restricted cohort was 409 individuals per 100 000 person-years (based on the 2001 Australian population). Risk factors after adjustment for potential confounders were older age (age ≥60 years vs age <50 years; hazard ratio [HR], 6.38; 95% CI, 4.65-8.75), male sex (HR, 1.56; 95% CI, 1.33-1.84), fair skin (vs olive, dark, or black skin; HR, 3.42; 95% CI, 1.66-7.04), inability to tan (vs ability to tan deeply; HR, 1.69; 95% CI, 1.19-2.40), previous excisions of keratinocyte cancers (ever had an excision vs never had an excision; HR, 6.28; 95% CI, 5.03-7.83), current smoking (vs never smoking, HR, 2.02; 95% CI, 1.59-2.57), and high alcohol use (≥14 alcoholic drinks per week vs no alcoholic drinks per week; HR, 1.42; 95% CI, 1.09-1.86). Conclusions and Relevance: This is, to date, the first large prospective population-based study to report the incidence rate and risk factors for KA. The high person-based incidence rate (409 individuals per 100 000 person-years) highlights the substantial burden of KA in Queensland, Australia. Furthermore, the study's findings suggest that older age (≥60 years), male sex, UV radiation-sensitive phenotypes, indications of high sun exposure (eg, previous keratinocyte cancer excisions), smoking, and high alcohol use are independent risk factors for the development of KA.

Web Application for the Automated Extraction of Diagnosis and Site From Pathology Reports for Keratinocyte Cancers.

PURPOSE: Keratinocyte cancers are exceedingly common in high-risk populations, but accurate measures of incidence are seldom derived because the burden of manually reviewing pathology reports to extract relevant diagnostic information is excessive. Thus, we sought to develop supervised learning algorithms for classifying basal and squamous cell carcinomas and other diagnoses, as well as disease site, and incorporate these into a Web application capable of processing large numbers of pathology reports. METHODS: Participants in the QSkin study were recruited in 2011 and comprised men and women age 40-69 years at baseline (N = 43,794) who were randomly selected from a population register in Queensland, Australia. Histologic data were manually extracted from free-text pathology reports for participants with histologically confirmed keratinocyte cancers for whom a pathology report was available (n = 25,786 reports). This provided a training data set for the development of algorithms capable of deriving diagnosis and site from free-text pathology reports. We calculated agreement statistics between algorithm-derived classifications and 3 independent validation data sets of manually abstracted pathology reports. RESULTS: The agreement for classifications of basal cell carcinoma (κ = 0.97 and κ = 0.96) and squamous cell carcinoma (κ = 0.93 for both) was almost perfect in 2 validation data sets but was slightly lower for a third (κ = 0.82 and κ = 0.90, respectively). Agreement for total counts of specific diagnoses was also high (κ > 0.8). Similar levels of agreement between algorithm-derived and manually extracted data were observed for classifications of keratoacanthoma and intraepidermal carcinoma. CONCLUSION: Supervised learning methods were used to develop a Web application capable of accurately and rapidly classifying large numbers of pathology reports for keratinocyte cancers and related diagnoses. Such tools may provide the means to accurately measure subtype-specific skin cancer incidence.

Body mass index and height and risk of cutaneous melanoma: Mendelian randomization analyses.

BACKGROUND: Height and body mass index (BMI) have both been positively associated with melanoma risk, although findings for BMI have been less consistent than height. It remains unclear, however, whether these associations reflect causality or are due to residual confounding by environmental and lifestyle risk factors. We re-evaluated these associations using a two-sample Mendelian randomization (MR) approach. METHODS: We identified single nucleotide polymorphisms (SNPs) for BMI and height from separate genome-wide association study (GWAS) meta-analyses. We obtained melanoma SNPs from the most recent melanoma GWAS meta-analysis comprising 12 874 cases and 23 203 controls. We used the inverse variance-weighted estimator to derive separate causal risk estimates across all SNP instruments for BMI and height. RESULTS: Based on the combined estimate derived from 730 SNPs for BMI, we found no evidence of an association between genetically predicted BMI and melanoma [odds ratio (OR) per one standard deviation (1 SD) (4.6 kg/m2) increase in BMI 1.00, 95% confidence interval (CI): 0.91-1.11]. In contrast, we observed a positive association between genetically-predicted height (derived from a pooled estimate of 3290 SNPs) and melanoma risk [OR 1.08, 95% CI: 1.02-1.13, per 1 SD (9.27 cm) increase in height]. Sensitivity analyses using two alternative MR methods yielded similar results. CONCLUSIONS: These findings provide no evidence for a causal association between higher BMI and melanoma, but support the notion that height is causally associated with melanoma risk. Mechanisms through which height influences melanoma risk remain unclear, and it remains possible that the effect could be mediated through diverse pathways including growth factors and even socioeconomic status.

Keratinocyte cancer excisions in Australia: Who performs them and associated costs.

BACKGROUND/OBJECTIVE: To describe the clinical settings in which keratinocyte cancers are excised in Queensland and describe the types of practitioners who excise them; to examine costs; and to identify predictors of hospital admission. METHODS: We used linked data for participants from the QSkin study (n = 43 794), including Medicare claims and Queensland hospital admissions relating to treatment episodes for incident keratinocyte cancers from July 2011 to June 2015. We used multinomial logistic regression to measure associations between demographic and clinical characteristics and treatment setting. The median costs of Medicare claims (AU$) were calculated. RESULTS: During 4 years of follow-up, there were 18 479 skin cancer excision episodes among 8613 people. Most excisions took place in private clinical rooms (89.7%), the remainder in hospitals (7.9% private; 2.4% public). Compared with other anatomical sites, skin cancers on the nose, eyelid, ear, lip, finger or genitalia were more likely to be treated in hospitals than in private clinical rooms (public hospital OR 5.7; 95%CI 4.5-7.2; private hospital OR 8.3; 95%CI 7.3-9.4). Primary care practitioners excised 83% of keratinocyte cancers, followed by plastic surgeons (9%) and dermatologists (6%). The median Medicare benefit paid was $253 in private clinical rooms and $334 in private hospitals. Out-of-pocket payments by patients treated in private hospitals were fourfold higher than those in private clinical rooms ($351 vs $80). CONCLUSIONS: Most keratinocyte cancers are excised in primary care, although more than 10% of excisions occur in hospital settings.

Association between Phenotypic Characteristics and Melanoma in a Large Prospective Cohort Study.

To delineate causal pathways for melanoma, it is essential to derive unbiased estimates of risk. Extant knowledge derives largely from case-control studies with potential for bias. In a population-based prospective study (QSkin, n = 38,854), we assessed melanoma risks associated with pigmentation characteristics and other phenotypes, and we explored additive interactions. We fitted Cox proportional hazards models to adjust for other factors to estimate the independent effects of each characteristic on melanoma risk. During a mean follow-up of 3.5 years, 642 (1.5%) participants developed melanoma (253 invasive, 389 in situ). The characteristics most strongly associated with invasive melanoma were self-reported nevus density at age 21 years (many vs. no moles hazard ratio [95% confidence interval] = 4.91 [2.81-8.55]), inability to tan (no tan vs. deep tan, hazard ratio [95% confidence interval] = 3.39 [1.85-6.20]), and red hair color (vs. black, hazard ratio [95% confidence interval] = 3.11 [1.50-6.43]). Propensity to sunburn was not associated with melanoma after tanning inability was adjusted for. People with both high nevus density and a history of multiple keratinocyte cancers had significantly higher melanoma risks than those with only one of those traits. We infer that melanoma risk is more strongly related to nevus density and inability to tan than susceptibility to sunburn.

Smoking and Cutaneous Melanoma: Findings from the QSkin Sun and Health Cohort Study.

Background: Previous studies suggest that smokers have lower risks of cutaneous melanoma than nonsmokers, but data from population-based prospective studies are scarce. We investigated associations between smoking and melanoma in a cohort study purpose-designed to investigate skin cancer outcomes.Methods: Participants with no prior history of melanoma (n = 38,697) completed a risk factor survey at baseline (2011). Patients were followed through linkage to the cancer registry. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between smoking (including intensity, duration, time since quitting) and melanoma using multivariate Cox proportional hazards regression, accounting for death as a competing event.Results: During a mean follow-up of 3.5 years, invasive melanomas developed in 247 participants. Compared with never smokers, former smokers (but not current smokers) had lower risks of invasive melanoma (HR 0.76; 95% CI, 0.57-1.01). Among former smokers, risks were lower with greater quantity of cigarettes smoked (HR 0.75; 95% CI, 0.56-0.98 per 10 cigarettes/day). No association was observed with duration of smoking while longer time since quitting was associated with a relative risk of melanoma that was not significantly different from the null (HR 1.18; 95% CI, 0.91-1.51, for every 10 years since quitting).Conclusions: We observed complex associations between smoking and melanoma, with some suggestion that former smokers had lower risks than never or current smokers. The apparent inverse association among former smokers may be due to residual confounding, although surveillance bias or biological effects cannot be excluded entirely.Impact: Smoking does not increase the risk of cutaneous melanoma. Cancer Epidemiol Biomarkers Prev; 27(8); 874-81. ©2018 AACR.

Risk Stratification for Melanoma: Models Derived and Validated in a Purpose-Designed Prospective Cohort.

Background: Risk stratification can improve the efficacy and cost-efficiency of screening programs for early detection of cancer. We sought to derive a risk stratification tool for melanoma that was suitable for the general population using only self-reported information. Methods: We used melanoma risk factor information collected at baseline from QSKIN, a prospective cohort study of Queensland adults age 40 to 69 years at recruitment (n = 41 954). We examined two separate outcomes: 1) invasive melanomas and 2) all melanomas (invasive + in situ) obtained through data linkage to the cancer registry. We used stepwise Cox proportional hazards modeling to derive the risk models in a randomly selected two-thirds sample of the data set and assessed model performance in the remaining one-third validation sample. Results: After a median follow-up of 3.4 years, 655 (1.6%) participants developed melanoma (257 invasive, 398 in situ). The prediction model for invasive melanoma included seven terms. At baseline, the strongest predictors of invasive melanoma were age, sex, tanning ability, number of moles at age 21 years, and number of skin lesions treated destructively. The model for "all melanomas" (ie, invasive and in situ) included five additional terms. Discrimination in the validation data set was high for both models (C-index = 0.69, 95% confidence interval [CI] = 0.62 to 0.76, and C-index = 0.72, 95% CI = 0.69 to 0.75, respectively), and calibration was acceptable. Conclusions: Such a tool could be used to target surveillance activities to those at highest predicted risk of developing melanoma over a median duration of 3.4 years.

Cigarette Smoking and the Risks of Basal Cell Carcinoma and Squamous Cell Carcinoma.

Sunlight is the principal environmental risk factor for keratinocyte cancers, but other carcinogens have also been implicated, including tobacco smoke. Findings have been conflicting, however. We investigated associations between cigarette smoking and incidence of basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) in QSkin, a prospective study of skin cancer (N = 43,794). Smoking history was self-reported at baseline; newly diagnosed BCCs and SCCs were ascertained through data linkage and verified by histopathology reports. We restricted analyses to white participants who at baseline reported no past history of skin cancer excisions and no more than five destructively treated actinic skin lesions. We fitted Cox proportional hazards models, adjusted for known confounders. Compared with never smokers, current smokers had significantly lower risks of BCC (hazard ratio = 0.6; 95% confidence interval = 0.4-0.9) but significantly higher risks of SCC (hazard ratio = 2.3; 95% confidence interval = 1.5-3.6). Former smokers had similar risks for BCC and SCC as never smokers. Among smokers, we observed no dose-response trends with duration of smoking, intensity, or time since quitting. On further analysis, current smokers had fewer skin examinations and procedures than never smokers, suggesting greater opportunities for detection among never smokers. Strengths include large sample size, prospective design, and virtually complete follow-up; however, histologic details were missing for a proportion of excised tumors. In conclusion, current smokers had a lower incidence of BCC (possibly because of detection bias) but higher rates of SCC.

Anatomical Distributions of Basal Cell Carcinoma and Squamous Cell Carcinoma in a Population-Based Study in Queensland, Australia.

IMPORTANCE: Keratinocyte cancers (KCs), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are the most common cancers among fair-skinned populations worldwide. Although studies have indicated that the anatomical distribution of BCC and SCC differ, few have compared them directly in well-defined population samples. OBJECTIVES: To describe and compare the anatomical distribution of BCC and SCC in a population-based sample in Queensland, Australia. DESIGN, SETTING, AND PARTICIPANTS: This study was nested within the population-based QSkin Sun and Health Study in Queensland, Australia. Of 37 103 study participants linked to national medical insurance records, 3398 diagnosed with KCs from September 1, 2010, to September 30, 2012, were identified, and information about their KCs was extracted from pathology reports. Data were analyzed from January 1, 2013, to March 30, 2016. MAIN OUTCOMES AND MEASURES: The relative tumor densities (RTDs) on defined body sites, calculated by dividing the proportion of tumors occurring at a specified site by the proportion of skin area of that site. RESULTS: A total of 5150 KCs with complete data were identified in 2374 study participants (1339 men [56.4%] and 1035 women [43.6%]; mean [SD] age, 59.7 [7.4] years). Of these, 3846 KCs (74.7%) were BCCs. Most BCCs were on the head and/or neck (1547 [40.2%]) and the trunk (1305 [33.9%]); most SCCs were on the head and/or neck (435 [33.4%]) and upper limbs (455 [34.9%]). The greatest differences in RTDs between BCC and SCC were on the hand (BCC:SCC ratio, 1:14) and the back and/or buttocks (BCC:SCC ratio, 8:1). Relative tumor densities of KCs were higher on the scalp and ear in men compared with women, and on the upper arm in women compared with men. The pattern of RTDs did not differ with age for BCC. Compared with younger adults (40-54 years), the RTDs in older adults (55-69 years) were 2-fold higher for SCC on the scalp (0.38 [95% CI, 0.00-0.81] vs 1.07 [95% CI, 0.75-1.38]) and the back and/or buttocks (0.05 [95% CI, 0.00-0.12] vs 0.12 [95% CI, 0.07-0.16]). CONCLUSIONS AND RELEVANCE: The high RTDs on sun-exposed body sites for BCC and SCC are in keeping with sun exposure as the primary etiologic factor for both tumors. However, for BCC, the low RTD on the hand and high RTDs on less sun-exposed sites suggest a complex association between sun exposure and occurrence of BCC. Knowledge about the anatomical distribution of BCC and SCC may provide insight into their diagnoses and causes.

A Model to Predict the Risk of Keratinocyte Carcinomas.

Basal cell and squamous cell carcinomas of the skin are the commonest cancers in humans, yet no validated tools exist to estimate future risks of developing keratinocyte carcinomas. To develop a prediction tool, we used baseline data from a prospective cohort study (n = 38,726) in Queensland, Australia, and used data linkage to capture all surgically excised keratinocyte carcinomas arising within the cohort. Predictive factors were identified through stepwise logistic regression models. In secondary analyses, we derived separate models within strata of prior skin cancer history, age, and sex. The primary model included terms for 10 items. Factors with the strongest effects were >20 prior skin cancers excised (odds ratio 8.57, 95% confidence interval [95% CI] 6.73-10.91), >50 skin lesions destroyed (odds ratio 3.37, 95% CI 2.85-3.99), age ≥ 70 years (odds ratio 3.47, 95% CI 2.53-4.77), and fair skin color (odds ratio 1.75, 95% CI 1.42-2.15). Discrimination in the validation dataset was high (area under the receiver operator characteristic curve 0.80, 95% CI 0.79-0.81) and the model appeared well calibrated. Among those reporting no prior history of skin cancer, a similar model with 10 factors predicted keratinocyte carcinoma events with reasonable discrimination (area under the receiver operator characteristic curve 0.72, 95% CI 0.70-0.75). Algorithms using self-reported patient data have high accuracy for predicting risks of keratinocyte carcinomas.

Medicare claims data reliably identify treatments for basal cell carcinoma and squamous cell carcinoma: a prospective cohort study.

OBJECTIVE: To investigate the accuracy of Medical Benefit Schedule (MBS) item numbers to identify treatments for basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). METHODS: We linked records from QSkin Study participants (n=37,103) to Medicare. We measured the proportion of Medicare claims for primary excision of BCC/SCC that had corresponding claims for histopathology services. In subsets of participants, we estimated the sensitivity and external concordance of MBS item numbers for identifying BCC/SCC diagnoses by comparing against 'gold-standard' histopathology reports. RESULTS: A total of 2,821 (7.6%) participants had 4,830 separate Medicare claims for BCC/SCC excision; almost all (97%) had contemporaneous Medicare claims for histopathology services. Among participants with BCC/SCC confirmed by histology reports, 76% had a corresponding Medicare claim for primary surgical excision of BCC/SCC. External concordance for Medicare claims for primary BCC/SCC excision was 68%, increasing to 97% when diagnoses for intra-epidermal carcinomas and keratoacanthomas were included. CONCLUSIONS: MBS item numbers for primary excision of BCC/SCC are reasonably reliable for determining incident cases of keratinocyte skin cancers, but may underestimate incidence by up to 24%. IMPLICATIONS: Medicare claims data may have utility in monitoring trends in conditions for which there is no mandatory reporting.

Sun Protection and Skin Examination Practices in a Setting of High Ambient Solar Radiation: A Population-Based Cohort Study.

IMPORTANCE: Primary prevention and early detection are integral strategies to reduce the burden of skin cancer. OBJECTIVES: To describe the prevalence of sun protection and skin examination practices in a population exposed to high levels of ambient solar radiation and to identify associated factors. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional analyses of baseline data from a prospective cohort of 40,172 adults aged 40 through 69 years from Queensland, Australia, recruited in 2011. We obtained data on all melanoma diagnoses through 2009 via record linkage with the Queensland Cancer Registry (notifications have been mandatory since 1982). MAIN OUTCOMES AND MEASURES: We calculated prevalence proportion ratios to compare prevalence of sun protection and skin examination practices in 3 separate groups: those with a history of melanoma (group 1), those with a self-reported history of treated actinic lesions (group 2), and those without either (group 3). We used multivariate generalized linear models to identify factors associated with each practice. RESULTS: Participants with a previously confirmed melanoma (group 1; n = 1433) and/or treated actinic lesions (group 2; n = 24,006) were more likely than those without (group 3; n = 14,733) to report sun protection practices, including regular use of sunscreen (53.3%, 45.1%, and 38.1%, respectively) and wearing hats (74.7%, 68.2%, and 58.2%, respectively). They were also more likely to have had a whole-body skin examination by a physician in the past 3 years (93.7%, 83.4%, and 52.1%, respectively). Within all 3 groups, the strongest association with sun protection practices was with sun-sensitive skin type. Within group 3 (no history of treated skin lesions), the strongest factor associated with clinical skin examinations was self-reported nevus density at 21 years of age, whereas a family history of melanoma was a significant factor in groups 2 and 3. CONCLUSIONS AND RELEVANCE: In this large sample exposed to high levels of ambient solar radiation, sun protection and skin examination practices were most frequent among those with a history of treated skin lesions or sun-sensitive skin types.