Triggers for transition from active surveillance to radical treatment of prostate cancer 2008-2020 - a case-control study.

Objective: To examine associations between objective signs of progression (triggers) and transition from active surveillance (AS) to radical treatment for prostate cancer (PC).

Patients and methods: This case-control study included men with low- or favourable intermediate-risk PC in the region of Halland, with data from The National Prostate Cancer Register (NPCR), Sweden, starting AS between 2008 and 2020. Cases were men who transitioned to radical treatment. For each case, 10 controls who remained in AS were selected without further matching. Triggers for transition to treatment were histopathological progression, magnetic resonance imaging (MRI) progression and increases in prostate-specific antigen (PSA) levels. We compared the probabilities for triggers between cases and controls, in 2008-2014 and 2015-2020, using logistic regression.

Results: Amongst 846 men, we identified 98 cases in 2008-2014 and 172 cases in 2015-2020. Histopathological progression was associated with transition, most strongly in the later period (2008-2014: odds ratios [OR] 6.88, 95% confidence interval [CI] 3.69-12.80; and 2015-2020: OR 75.29, 95% CI 39.60-143.17). MRI progression was associated with transition in 2015-2020 (OR 6.38, 95% CI 2.70-15.06), whereas an increase in PSA was weakly associated with transition in the early period. The absence of triggers was associated with no transition (2008-2014: OR 0.24, 95% CI 0.15-0.40, and 2015-2020: OR 0.09, 95% CI 0.06-0.14). The probability of no trigger was 27% in cases 2015-2020.

Conclusion: The increase in association between histopathological trigger and transition to treatment indicates increased quality of AS. Still, amongst men treated from 2015 to 2020, 27% transitioned without any trigger.