Room
Salle Delos ( traverser la route - bâtiment de liaison )
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Theme
Cancer - Cancer research and prevention results
Chair
Sonia Pellegrini
Title
A cohort analysis of residential radon exposure and melanoma incidence in Swiss cantons
Name
Seçkin Boz
Affiliation
Swiss Tropical and Public Health Institute
Abstract
Background and Aim: Radon is radioactive noble gas found in earth crust. It tends to accumulate in buildings, and is estimated to account for half of the ionizing radiation dose received by humans. Skin is the second most exposed organ to ionizing radiation from radon. The aim of this study was to evaluate the association between residential radon exposure and melanoma incidence in selected Swiss cantons.Methods: The study included 1.3 million adults (20 years and older) from the Swiss National Cohort (SNC) who were residents in the cantons of Vaud, Neuchâtel, Valais, Geneva, Fribourg, and Ticino at the study baseline (04.12.2000). Cases of primary tumours (ICD-O-3: 8720-8790 melanoma) were identified using data from these cantonal cancer registries, linked to the SNC. Long-term residential radon and ambient ultraviolet exposure from sun were assigned to each individual’s addresses at baseline. We used Cox proportional hazard models with age as the underlying time scale and adjusted for age group and radon exposure interaction, canton, socioeconomic position, educational attainment, civil status as fixed explanatory variables and stratified by sex, mother tongue and outdoor occupation with potential sun exposure. Potential effect modifiers were also tested.
Results: Among the study population, we observed 4937 incident cases of melanoma during an average 8.9 years of follow-up. The adjusted hazard ratio for per 100 Bq/m^3 increase in residential radon levels for age group 20-29 was 1.68 (95% CI: 1.29, 2.19). Radon effect was significant only within this age group and became null at higher ages. There is no effect modification of radon exposure on the risk of developing skin cancer.
Conclusion: Residential radon exposure might be a relevant risk factor for melanoma incidence, especially for people at younger ages. Accumulation of radon gas is preventable via built-in solutions applicable to dwelling. Such measures are important for public health.
Keywords: radon, incidence, melanoma, squamous cell carcinoma, basal cell carcinoma, prospective cohort, Switzerland
Title
A cohort analysis of residential radon exposure and melanoma incidence in Swiss cantons
Name
Karen Brändle
Affiliation
Abstract
The Vaud colorectal cancer (CRC) screening program, pioneer in Switzerland, offers since 2015 the choice between a biennial fecal immunological test (FIT) and a colonoscopy every 10 years to those aged 50 to 69. This is one of the few organised programs in Europe to offer the choice between these two screening modalities.The first epidemiological evaluation of a Swiss CRC screening program, which covered the 2015-2021 period, used established indicators and norms (European guidelines). It showed an increasing uptake over the years but with regional differences. The overall raw participation rate (24%) is an under-estimation since it assumes that all invited are medically eligible and not already up to date with screening recommendations. Based on a research survey of non-participants, which suggests that about one-third of non-participants might be eligible at time of invitation, the true participation rate in the program lies likely around the minimal recommended threshold of 45%.
Choice of tests was equally distributed, with significant regional differences. In a context of rather limited availability for colonoscopy, the increased uptake led to too long waiting times in some regions (1 to 6 months for screening colonoscopy; 44 to 69 days for follow-up colonoscopy). Quality of both FIT and colonoscopy met the European norms. Age-adjusted detection rate was 3.7/1000 persons-screened for CRC, 47/1000 for advanced adenomas and 132.8/1000 for non-advanced adenomas. The high proportion of early-stage cancers (60% stage I) was in line with European standards.
The large increase in screening tests and limited colonoscopy capacity is leading to interprofessional discussions on strategies for prioritizing FIT, accompanied by additional orientation tools within the program and public sensitization, and for reducing the delay to perform colonoscopies after FIT positive results.
Title
Personalizing skin cancer prevention through UV photography: A feasibility study
Name
Jean-Luc Bulliard
Affiliation
Department of Epidemiology and Health Systems (DESS), University Center for General Medicine and Public Health (UNISANTE), Lausanne
Abstract
Introduction: Solar ultraviolet (UV) is the main causative factor for skin cancers (melanoma and epithelial skin cancer) and people with high levels of UV-exposed leisure or occupational activities are at increased risk. Despite longstanding and varied prevention campaigns, Switzerland has still among the highest incidence of skin cancer in Europe, suggesting that new prevention approaches are needed. This study aimed at demonstrating the feasibility and acceptability of a skin cancer prevention service using UV photography and personalized prevention messages, targeting groups with chronic UV exposure.Material and methods: A total of 440 people in 13 public and private sites spread in Vaud canton filled an electronic questionnaire to gather information on their photo susceptibility and photo protection habits. The VISIA7 (Canfield®) camera was used to take facial photographs and count UV spots and wrinkles of each participant. Based on these data and the photograph, a personalized prevention message was delivered on the spot by a trained nurse. A follow-up questionnaire was sent 3 months later to participants to assess potential change in their UV protection habits.
Results: Participants (median age 44; 58% of men; 52% outdoor workers) reported overall a relatively high level of sun protection, in line with earlier studies, ranging from 8% wearing long sleeves to 71% wearing sunglasses. An average of 343 UV spots were measured. Main determinants of a higher number of UV spots were being older, female, more educated and mainly having a lighter phototype (R2 = 0.53).
Preliminary results of the follow-up questionnaire, completed so far by 255 participants (58%), indicate that a lighter phototype, site of intervention and a higher number of UV spots, but not reported levels of sun protection habits, were positively associated with compliance. About half of participants self-reported a positive change triggered by the intervention. Follow-up participants significantly increased the use of all assessed means of UV protection (shadow, long sleeves, hat, glasses, sunscreen) by 6 to 17%. Wearing a hat showed the largest increase in absolute use (from 55% to 72%) and wearing long sleeves the most modest change (from 8% to 14%). Self-perceived reason for favorable change in UV protection behavior seem to be primarily linked to the personalized protection message or the whole procedure rather than the photograph alone. Final results will be discussed along with lessons learnt from this new prevention service.
Title
Cervical Cancer Prevention and Care Indicators for Women Living with HIV in Africa
Name
Maša Davidović
Affiliation
Swiss Tropical And Public Health Institute
Abstract
Background: In sub-Saharan Africa (SSA), 21% of all cervical cancer (CC) cases are attributable to HIV infection and globally 85% of all CC cases attributed to HIV are in SSA. Global CC elimination goals cannot be reached without scaling up CC prevention and care. The aim of the study was to develop internationally agreed-upon facility-based indicators to monitor and scale up CC prevention and care services for girls and women attending HIV clinics in SSA.Methods: We reviewed the literature to identify indicators for monitoring cancer control programs. We extracted relevant indicators and grouped them in domains along the CC prevention and care continuum. We used a modified, three-round e-Delphi method to reach consensus on indicators. Utilizing infrastructure and partnerships developed with the International epidemiology Databases to Evaluate AIDS (IeDEA) Network, we invited CC and HIV/AIDS prevention and care experts from SSA to participate. Through an anonymous, iterative process, they adapted the indicators to their context (Round 1), then rated (Rounds 2 and 3) and ranked them (Round 3). They rated indicators for predefined criteria (feasibility, understandability, reliability, relevance, comparability) on a 5-point Likert scale (1–very low, 5–very high) and ranked them by importance using QualtricsXM. Consensus was reached when >70% of respondents rated an indicator as high/very high in three or more criteria.
Results: We reviewed 47 policy documents from 21 African countries or international organizations, extracted 509 indicators, and pre-selected 30 indicators. The Delphi consensus process included 72 experts from 15 SSA countries. Consensus was reached for 17 indicators in the domains: primary prevention (n = 2); secondary prevention (screening, triage, and treatment) (n = 11), tertiary prevention (n = 2); and impact and linkage to HIV services (n = 2) (Table 1). Of 30 indicators, 5 reached consensus in all 5 criteria: number of women screened, cervical screening rate, screening test positivity rate, treatment rate of precancerous lesions and CC incidence rate.
Conclusion: We recommend implementing the 17 indicators that reached consensus into routine data collection practice at HIV clinics that offer CC prevention and care services in SSA. Indicators can be adapted for use in other countries and regions.
Title
Swiss colorectal cancer risk distribution and its implications for personalized screening
Name
Luuk van Duuren
Affiliation
Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland; Department of Public Health, Erasmus University Medical Center, Rotterdam, Netherlands
Abstract
PurposePersonalized screening based on risk prediction tools such as the QCancer score (QC) might improve screening efficiency. The QC score estimates an individual’s 15-year risk of colorectal cancer (CRC). A rapid recommendation (BMJ 2019) advises to screen adults with a QC score above 3% only, without considering population-level effects. We aimed to investigate these population effects in Switzerland.
Methods
We derived the QC distribution for 5 quinquennial age groups (50-54, 55-59, …, 70-74) using Swiss Health Survey 2012 data and calculated, for each age group, the fraction of the population for which the QC score exceeds 3% from that age. This represents the start age for CRC screening for each fraction. We then calibrated the MIscrosimulation SCreening ANalysis-Colon (MISCAN-Colon) model to Swiss CRC incidence and stage distribution data and evaluated screening with biennial Fecal Immunochemical Test (FIT) (cutoff 15 µg/g) from one’s starting age until age 75. Uniform screening with biennial FIT from age 50, 60 (males only) and 65 (females only) were also evaluated. For all 4 screening approaches we report a) mortality reduction compared to no screening, and b) Number Needed to Screen (NNS) to prevent one CRC death.
Results
Using a QC score threshold of 3% to start screening would imply that 76% of females are not screened before age 65 and 74% of males not before age 60. This risk-based screening approach would result in 31.9% mortality reduction in females and 36.5% in males, at an NNS of 762 for females and 741 for males. In comparison, uniform screening from age 50 would prevent 42.6% of CRC deaths in females and 41.2% in males, albeit at higher NNS (1436 and 1086 respectively). Screening all females from age 65 and all males from age 60 resulted in similar reductions in mortality (30.9% for females and 36.0% for males) as screening based on the QC score, at NNS of 593 and 706, respectively.
Discussion
The rapid recommendation implies that the majority of males and females start screening at age 60 and 65, respectively. Compared to uniform screening from age 50, this risk-based approach results in a lower NNS but also a lower mortality reduction. However, compared to uniform screening from age 60 or 65, the mortality reduction is similar while the NNS increases. This suggests that age- and sex-based screening prevailed on screening based on the QC score.