Introduction:

Low-grade prostate cancer is widely considered to be an indolent disease, based on excellent short-term survival rates. To obtain an accurate representation of prostate cancer mortality it is important to follow patients for sufficient time to capture most prostate cancer-related deaths. The objective of our study was to analyze prostate cancer mortality rates up to 25 years from diagnosis using a large population-based cohort of unselected prostate cancer patients.

Methods:

We conducted a population-based, cohort study using data from the Surveillance, Epidemiology and End-Results (SEER) program. We identified 116,796 prostate cancer cases diagnosed between 1992-1997 and followed them until 2017. Our primary outcome was prostate cancer-specific survival. We calculated annual prostate cancer mortality rates and actuarial survival rates using by age of diagnosis, tumour grade and race. 

Results:

The annual prostate cancer mortality rate was 1.5%.  The rate was higher than this for older men (2.1%), for Black men (1.9%) and for men with cancer of Gleason Score 7 and above (3.1%).  There were 21,896 deaths from prostate cancer (23% of all deaths). The majority of deaths (55.6%%) occurred in men initially diagnosed with low-grade disease. Among men initially diagnosed with high-grade cancers, most deaths (54.3%) occurred in the first five years. Among men initially diagnosed with low-grade cancers, most deaths (70.1%) occurred after five years. 

Conclusion:

In this large cohort study, the annual prostate-specific mortality for men with low- grade disease increased with time since diagnosis. The majority of deaths from prostate cancer in the US occur in men initially diagnosed with low-grade disease.  

Funding: N/A