The study shows that the association of BMI and smoking with prostate cancer risk in Sweden has changed with the introduction PSA testing, which is likely an effect of differential uptake of PSA testing in men according to BMI level and smoking habits.
More specifically, since PSA testing was introduced in Sweden, obesity and smoking are associated with a lower risk for prostate cancer. In previous studies, men with obesity or who smoke have shown lower attendance in prostate cancer screening, which leads to no or a later detection of the disease.
The study was published in Scientific Reports. Länk: Association of height, BMI, and smoking status with prostate cancer risk before and after the introduction of PSA testing in Sweden | Scientific Reports