Trends in Prostate Cancer Mortality

Sammanfattning: In the early 20th century, cancer of the prostate was considered a rare and deadly disease with little to no possibility of cure. Since then, prostate cancer management has improved substantially with earlier detection, hormonal therapy, surgery and radiotherapy of the prostate. Nevertheless, prostate cancer remains the leading cause of cancer death in men in Western countries. The purpose of this thesis was to study trends in prostate cancer mortality including investigations of adjudication and measures of prostate cancer death. In paper I, we studied whether increased use of radical treatment in men with locally advanced prostate cancer diagnosed between 2000-2016 has affected prostate cancer mortality in the Swedish population. The use of radical treatment almost tripled and 5-year cumulative incidence of prostate cancer death declined from 17% to 10% for all men below age 80 with locally advanced prostate cancer. In paper II, we compared relative and cause-specific survival in all men with prostate cancer, according to age at death and risk category at diagnosis. Older men with low-risk prostate cancer at diagnosis had a substantially higher relative survival compared to cause-specific survival, 116% vs. 96% at five years after diagnosis. Despite efforts to increase comparability of expected survival, relative survival remained above 100% in these men due to healthy selection bias. In paper III, we assessed the amount of evidence in support of prostate cancer as the cause of death by review of health care records for 495 men who between 2011-2018 died of prostate cancer according to the Cause of Death Register. Older men and men with low-risk prostate cancer at diagnosis had considerably less evidence in support of prostate cancer death compared with younger men and men with high-risk disease. In paper IV, we applied a simulation model to estimate the lifetime risk of prostate cancer for different levels of diagnostic activity and life expectancy. Men exposed to high diagnostic activity had five-fold life-time risk of low or intermediate-risk prostate cancer and half the lifetime risk of high-risk or metastatic prostate cancer compared to men exposed to low diagnostic activity. Long life expectancy moderately increased the lifetime risk of prostate cancer in all risk categories, especially high-risk disease.