Matthias Lorez

Evaluation of completeness of case ascertainment in Swiss cancer registration

This is the first comprehensive evaluation of completeness of case ascertainment in Swiss cancer registration. There is currently no method available that is considered to be the gold standard. Apart from simple measures such as the proportion of cases where registration was initiated by a death certificate and the proportion of diagnoses on the basis of histology or cytology/haematology, we applied two dedicated approaches: (i) the semiquantitative method of comparing the mortality to incidence rate ratio with relative survival (MI-Surv method) and (ii) the Flow method, which provides a quantitative estimate for the completeness depending on time since diagnosis. All 10 Swiss cancer registries in operation since at least 2006 and providing the required parameters were included. Simple and dedicated methods showed high completeness across all cancer registries and for most cancer types tested, with the notable exception of lymphoid leukaemia.

Trends in prostate cancer incidence between 1996 and 2013 in two Swiss regions by age, grade, and T-stage

PurposeTo investigate differences in prostate cancer incidence between two distinct Swiss regions from 1996 to 2013 stratified by age group, grade, and T-stage.MethodsThe dataset included 17,495 men living in Zurich and 3,505 men living in Ticino, diagnosed with prostate cancer between 1996 and 2013. We computed age-standardized incidence rates per 100,000 person-years using the European Standard Population. Trends were assessed using JoinPoint regression analysis Software.ResultsAge-standardized incidence rates were generally higher in Zurich compared to Ticino but the difference decreased over time. Incidence rates increased significantly up to 2002 in Zurich and 2007 in Ticino and then decreased. A statistically significant increase was observed for men aged < 65 years, for grade 3 tumors, and for T-stage 2 and 3 tumors. The largest decrease was seen for grade 1 tumors. Furthermore, the incidence of tumors of unknown grade or T-stage decreased significantly in both regions.ConclusionsThe trends in prostate cancer incidence rates were similar in both regions, although on a higher level in Zurich compared to Ticino. However, the difference decreased over time. The distribution of T-stage and grade did not explain the difference in incidence rates. Different use of opportunistic screening may play a role.