Unravelling the natural history of localised prostate cancer in the post-prostate specific antigen era: implications for clinical management.

Background: Management of localised prostate cancer (PCa) remains controversial in the era of prostate-specific antigen (PSA) testing. This study aims to describe the natural history of men with PCa being followed up expectantly to evaluate disease mortality.

Methods: After exclusion, clinical data of 204 patients retrieved from a prospective large PCa registry were reviewed. Competing risk analysis were performed using the Fine-Gray model.

Results: The median age was 73 years old with a median follow up of 12.5 years. The median PSA was 8.85 ng/mL and the risk stratification were as follows: low (47.0%), intermediate (31.4%), and high risk (21.6%). There were 19 PCa (9.3%) and 84 non-PCa deaths (41.2%), with overall mortality at 50.5%. Multivariate analysis showed patients with high PSA values [subdistribution hazard ratio (sdHR) 7.13], poorer prostate cancer grade groups (PCGG) (sdHR 16.349), and therefore higher European Association of Urology risk group (sdHR 11.42) had greatly elevated prostate cancer mortality (PCM). Older patients greater than 75 years of age (sdHR 4.52) and high Charlson Comorbidity Index (CCI ≥6) scores had higher non-prostate cancer mortality (NPCM) (sdHR 7.87). Subgroup analysis of the high-risk group showed having a lower CCI score (≤3) had a greater risk of PCM than NPCM (sdHR 4.31 vs. 0.22) while the converse is observed for higher CCI scores (1.12 vs. 5.52).

Conclusions: Overall PCM remains low in elderly men with conservatively treated PCa. Age and poorer CCI predict NPCM while PSA and PCGG predict PCM. In high-risk PCa group, CCI is a useful tool to determine which patients will benefit from radical treatment.