European Multidisciplinary Cancer Congress (EMCC) 2011, 23-27 September, Stockholm
Cost effective ways to predict prostate cancer 1/2
Dr Stig Bojesen – Copenhagen University Hospital, Denmark
Thank you. This study was led by David Orsted, I’m the second author of this: Associations of Benign Prostate Hyperplasia with Prostate Cancer Incidents and Mortality.
Benign prostate hyperplasia is a very frequent condition in men in the affluent world, about 70% of men above 70 years of age have this condition and we asked ourselves whether it is associated with prostate cancer and with prostate cancer death. The two conditions or diseases have several things in common: they’re both dependent on hormonal signals to grow but they are also different in the way that the hyperplasia is located mainly around the urethra and the cancer is located more peripheral.
We made a nationwide association study including all Danish men, from 1980 to 2006; using the Danish Health Registries we were able to make studies on individual participant data. So we had around three million men and we ascertained the benign prostate hyperplasia in different ways – either the men were hospitalised with the condition, about 200,000 men, or they were operated on for benign prostate hyperplasia, 78,000 men, and we had 2.8 million controls. In the whole period we had 53,000 cases of prostate cancer and 25,000 cases of prostate cancer death.
So this is the overall picture: on the y-axis you have the cumulative incidence of prostate cancer as a function of age in years. The red line represents the men who were hospitalised with benign prostate hyperplasia and the blue line represents the general population controls. We see that the men with benign prostate hyperplasia have a 2.2 fold risk of developing prostate cancer compared to the controls, and this was highly significant, p less than 10-300.
Because diagnosis of benign prostate hyperplasia could affect the ascertainment of prostate cancer, we also looked upon prostate cancer death which is less prone to be influenced by ascertainment due to PSA measurements. Here we have the general population’s controls with the hazard ration of 1. For men hospitalised for benign prostate hyperplasia we have a hazard ratio of prostate cancer death of about 2 and the men who were operated on for BPH had a hazard ratio of about 8, so they’re in their own confidence intervals as shown here.
Our conclusions were that benign prostate hyperplasia is associated with increased risk of prostate cancer and increased risk of prostate cancer death. This association is done in an epidemiological study and cannot infer any causality.