Bridie S. Thompson

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).

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.

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.

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.

Hormonal and reproductive factors and incidence of basal cell carcinoma and squamous cell carcinoma in a large, prospective cohort

To the Editor: Previous research suggests that hormonal factors might influence the development of keratinocyte cancers (KCs), but the evidence is inconsistent. A potential mechanism for the association is photosensitization with use of estrogen, a hormone included in menopausal hormone therapy (MHT). We examined the association between hormonal and reproductive factors and subsequent risk for first histologically confirmed primary basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) in a large cohort of women that was well-characterized with respect to important potential confounding factors, as well as clinical factors that might inform about possible detection bias. White women from the QSkin Sun and Health Study with no history of melanoma, excisions for skin cancer, or [5 self-reported ablations for sunspots or skin cancers (n 1⁄4 11,152) were eligible for the study. The latter criterion was stipulated to minimize potential bias caused by including women with prior disease in the analyses, considering that KCs can be ablated without a histologically confirmed diagnosis. Information on hormonal and reproductive factors was self-reported at baseline (2011). KC outcomes were identified from the administrative medical claims data (Medicare, Australia’s universal health insurance scheme) until June 30, 2014, and exact diagnoses of BCC and SCC were determined through linked pathology records. We used Cox proportional hazards models to estimate the hazard ratios (HRs) associated with oral contraceptives (OCs) andMHT, age atmenarche, menopausal status, age atmenopause andparity, and first histologically confirmed BCC or SCC while taking into account the effects of age, sun exposure, and phenotypic and lifestyle characteristics. Selected characteristics of the study cohort, overall and amongst postmenopausal women stratified by MHT use, are provided in Supplemental Table I (available at http://www.jaad.org). During a median follow-up of 3 years, 336 women developed

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

1 BCCs (mean age 55.0 years) and 85 women,

A Model to Predict the Risk of Keratinocyte Carcinomas

1 SCCs (mean age 55.6 years). We found no association between incidence of BCC or SCC and OC use (ever or never, duration), parity, or age at menarche or menopause (Tables I and II). Among postmenopausal women, ever (vs never) use of MHT at baseline was associated with an increased risk for BCC (adjusted HR 1.46; 95% confidence interval 1.07-1.97), but there was no dose response with duration of use (Ptrend 1⁄4 .2; Table I). MHT use was not associated with SCC (adjusted HR 0.79; 95% confidence interval 0.45-1.38). We investigated detection bias as a possible explanation for the positive association between MHT use and BCC through analyses stratified by self-reported history of skin checks by a doctor and number of Medicare claims for doctor consultations, biopsies, and cryotherapy treatments during follow-up; we observed no material difference in the effect estimates according to these factors. The association between MHT use and BCC did not differ materially across strata of sun exposure variables (data not shown). Our findings in relation to both OC and MHT use and risk for BCC accord with findings from 2 other prospective studies, the US Radiologic Technologists Study and the Danish Diet, Cancer, and Health cohort, although a significant trend with durationofMHTusewasobserved in theUSRadiologic Technologists Study cohort. Limitations of our study was the relatively short follow-up and constrained sample size that limited analyses for SCC. In summary, we did not observe an association between OC use or reproductive factors and incidence of BCC or SCC, but we did find a modest positive association between ever use of MHT and BCC only. Although we found no conclusive evidence of detection bias or confounding to explain the latter finding, in view of the lack of a dose-response relationship, we counsel cautious interpretation until further longitudinal studies have explored these associations.