Geneva Cancer Observatory Goes Online

The Geneva Cancer Registry has published on its website an interactive dashboard showing the evolution of cancer incidence and mortality in the canton since 1970. It is well worth a visit.

Which type of cancer is most common? Which has the highest mortality rate? What are the differences between men and women? And how has the situation evolved over fifty years? Since 1970, the Geneva Cancer Registry (RGT), hosted at the Faculty of Medicine, has kept rigorous and comprehensive statistics on every cancer case diagnosed in the canton and on the deaths attributed to it. Until recently, however, this valuable data was distributed only as a PDF document or an Excel spreadsheet — admittedly not the easiest formats to work with. It is now presented through an interactive dashboard. This web-based tool makes it far easier to navigate this wealth of information, letting users combine parameters freely and quickly generate a clear, accessible picture of the cancer situation in Geneva. Developed by Évelyne Fournier, epidemiologist and data manager at the RGT, and her colleagues, the site is aimed at the general public, healthcare professionals, authorities, the media and, of course, researchers. Still evolving, it is expected to gain new features in the coming months.

"Similar interactive dashboards on cancer already exist elsewhere in the world, notably in the United States and the European Union," explains Marc Ryser, professor at the Department of Community Health and Medicine (Faculty of Medicine) and director of the RGT, "but in Switzerland, this is the first. We recently presented it at an international conference, and given the interest it generated, we've already shared our tool's source code with colleagues who requested it."

At a glance

Right from the homepage, visitors learn that the canton records an average of 3,648 new cancer diagnoses and 913 cancer deaths each year. These figures are five-year rolling averages, so they change little from week to week even though the site is regularly updated.
Clicking the "key figures" button reveals further detail. At a glance, we learn that for men, the most common cancer is prostate cancer (449 new cases per year on average over the past five years), while the deadliest is lung and bronchial cancer (91 deaths per year, or 19% of all cancer deaths). For women, breast cancer dominates across the board, with 424 average annual cases and 78 deaths per year (18% of all cancer deaths).
Users can also explore incidence and mortality indicators by tumour site (lung, breast, prostate, colon, etc.), by sex, and by year. They can also track trends for each tumour type, as well as the evolution of the canton's population between 1970 and 2023.
They can choose to include only invasive cancers — those that have already crossed the basal membrane of the affected organ and begun to spread — or add "in situ" cases, which are benign or uncertain and less dangerous. Results are displayed through a variety of graphs and tables. Each cancer type (there are 30 categories) also has its own detailed fact sheet.

A survival indicator

The same data can be viewed three ways: as average case counts, as rates per 100,000 people (which removes the effect of population growth), or as "standardised" rates per 100,000 people. This last indicator is the most useful for specialists. To compare different times or regions, epidemiologists recalculate rates as though the population always had the same age structure — that of a standard European population (ESP 1976), fixed by international convention. This neutralises the effect of ageing, so that a rise in cases reflects a genuine change in risk rather than simply the fact that Geneva's population today includes more older people.
"The latest indicator we've added is age-specific rates (under 50, 50 to 74, and over 75)," Évelyne Fournier continues. "It shows how the fifty-year evolution of incidence or mortality can diverge considerably between these three groups. And before the end of the year, we'd like to add a survival indicator for each cancer type. That will make it possible to visualise both crude survival — the proportion of patients still alive, regardless of cause of death — and net survival, which estimates survival specifically linked to the cancer, and to track how each changes over time."

Backed by legislation

The Geneva Cancer Registry records every cancer case among adults aged 20 and over residing in the canton of Geneva. Since 2020, its activity has been governed by the Federal Act on the Registration of Cancer Diseases (LEMO), which requires all healthcare professionals to report certain information to cantonal registries whenever a patient receives a cancer diagnosis or is already undergoing treatment. The aim is to standardise cancer registration across Switzerland in order to track trends over time, target prevention and screening efforts, improve patient care, and support epidemiological research. Patients retain the right to opt out of registration. In Geneva, only a handful do so each year. For ethical reasons, the dashboard's data is structured in a way that makes re-identification impossible. 
Easy to use and open to everyone, the dashboard is also a way of giving back to the public a service funded by their taxes. The hope is that Geneva residents will now make this tool their own. "We'd been missing a dashboard like this at the RGT for a long time. Artificial intelligence finally convinced us to take the plunge," admits Évelyne Fournier. "Ten years ago, a tool like this would have required resources we simply didn't have. AI has changed that. A few months of work were enough, where it once would have taken a dedicated team and dedicated funding."

Translated from Un observatoire du cancer à Genève est mis en ligne, an article by Le Journal de l'UNIGE.

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