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BackgroundSurvival after diagnosis is a fundamental concern in cancer epidemiology. In resource-rich settings, ambient clinical databases, municipal data and cancer registries make survival estimation in real-world populations relatively straightforward. In resource-poor settings, given the deficiencies in a variety of health-related data systems, it is less clear how well we can determine cancer survival from ambient data.MethodsWe addressed this issue in sub-Saharan Africa for Kaposi's sarcoma (KS), a cancer for which incidence has exploded with the HIV epidemic but for which survival in the region may be changing with the recent advent of antiretroviral therapy (ART). From 33 primary care HIV Clinics in Kenya, Uganda, Malawi, Nigeria and Cameroon participating in the International Epidemiologic Databases to Evaluate AIDS (IeDEA) Consortia in 2009-2012, we identified 1328 adults with newly diagnosed KS. Patients were evaluated from KS diagnosis until death, transfer to another facility or database closure.ResultsNominally, 22% of patients were estimated to be dead by 2 years, but this estimate was clouded by 45% cumulative lost to follow-up with unknown vital status by 2 years. After adjustment for site and CD4 count, age

Tobacco smoking is a strong risk factor for cancer, but associations with basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) of the skin have been inconsistent. We prospectively investigated the associations between cigarette smoking and 3-year incidence of first primary BCC or SCC in the QSkin cohort (n=43765). Smoking history was self-reported at baseline; newly diagnosed and surgically treated BCCs and SCCs were ascertained through linkage to the national health insurance scheme and verified by histopathology reports. We restricted our analyses to white participants who at baseline reported no past history of skin cancer excisions or cutaneous melanoma (registry-confirmed) and no more than 5 destructively-treated skin lesions (n=18830). Cox proportional hazards regression analysis was used to examine the association between smoking status and risk of BCC and SCC, adjusted for demographic and phenotypic characteristics and sun exposure history. Current smokers had significantly lower risks of BCC (HR 0.6; 95% CI, 0.4-0.9) but significantly increased risks of SCC (HR 1.9; 95% CI, 1.1-3.1) compared with never smokers. Former smoking was not associated. In analyses restricted to people with no past history of destructively-treated lesions (n=13323), we found a non-significant decreased risk of BCC (HR 0.8; 95% CI, 0.5-1.3) and a significant increased risk of SCC (HR 2.3; 95% CI, 1.3-4.4) among current smokers compared to never smokers. Future analyses will investigate associations with age at initiation, duration and intensity of smoking, and time since quitting. These findings suggest current smoking is a risk factor for cutaneous SCC but not BCC.

The costs of diagnosing and treating basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) are the highest of all cancers in Australia. However, information regarding incidence, multiplicity and risk are scarce as keratinocyte cancers (KCs) are not captured by most registries. To address these gaps, we initiated the QSKIN Study in 2010 recruiting 43,794 Queensland residents from a population register (participation 24%). Participants self-completed a baseline survey recording information on residential history, sun exposure, phenotype and medical and family history. We identified keratinocyte cancers through linkage to the national insurance register, confirming histopathology where possible. During the first three years of follow-up, 6936 (17%) participants had at least one KC excised; 1626 (4%) had 3 or more excisions. Of lesions with known histology, there were 9713 BCCs (in 4080 people) and 3505 SCCs (in 1782 people). We developed a tool to predict the risk of developing KC using backwards stepwise logistic regression models. The primary model retained terms for 10 items, including history of >20 prior skin cancers excised (OR 8.6), >50 skin lesions destroyed (OR 3.4), age >70 years (OR 3.5) and fair skin color (OR 1.8). Discrimination was high (Area under ROC 0.80, 95%CI 0.79-0.81) and the model appeared well calibrated. Among those reporting no prior history of skin cancer, a model with 10 factors (including age, sex, ethnicity and phenotypic factors) predicted KC events with reasonable discrimination (AUROC 0.72, 95% CI 0.70-0.75). The tool is undergoing external validation in primary care skin cancer clinics.

Estrogens have photosensitizing properties, but few prospective studies have examined the relationship between hormonal and reproductive factors and incidence of basal cell carcinoma (BCC) in women. Previous findings have been inconsistent, particularly in relation to parity and use of oral contraceptives (OCs) and menopausal hormone therapy (MHT). Given the heterogeneity in the literature, we sought to examine the association between hormonal and reproductive factors and BCC risk in a cohort of women (n=23,879) enrolled in the QSkin Study in 2011. The baseline survey included questions about use of OCs and MHT, age at menarche, menopausal status, age at menopause and parity. We restricted our analysis to white women with no past history of treatments for skin cancer and less than 6 treatments for actinic keratoses (n=11,204) and used Cox proportional hazards models to estimate the hazards ratio associated with each potential hormonal/reproductive factor and first histologically confirmed BCC, while taking account of the potentially confounding influence of sun exposure history, phenotypic characteristics, body mass index and smoking history. During a median follow-up duration of 2.95 years, 352 women developed BCC. In preliminary analyses, amongst post-menopausal women, ever use of MHT at baseline was associated with an increased risk of developing BCC compared to never users (adjusted HR1.4; 95%CI 1.1-1.9), but risk did not differ by duration of use. We found no association between parity, age at menarche, age at menopause or use of OCs and BCC incidence. Future work will examine whether MHT use is associated with an increased risk of a second primary BCC.