Abstract: PD28-12
Sources of Funding: None

Introduction

Active surveillance (AS) for low-risk prostate cancer is increasingly utilized, however, whether men with GS 3+4 disease are appropriate candidates remains a matter of debate. We evaluated the effects of the initial Gleason grade on biopsy progression, treatment and outcomes after radical prostatectomy (RP).

Methods

We prospectively followed men on AS at our institution between 1990 and 2016. Those diagnosed with Gleason 3+3 or 3+4 were included. Life tables were used to estimate progression-free survival (progression defined as increase in Gleason grade ?3+4 or volume >33% positive cores or >50% single core), treatment-free survival, and PSA recurrence-free survival after delayed RP. Multivariate Cox proportional hazards regression was used to determine risk factors for progression, treatment and recurrence after RP. Multivariate logistic regression was used to determine risk factors for adverse pathology (defined as Gleason ?4+3 or stage ?pT3b or pN1) at RP. Models were adjusted for age, race, PSA density (PSAD), total number of biopsies and percentage of cores positive at diagnosis.

Results

We included 1,171 men with Gleason 3+3 or 3+4 on initial biopsy and ?1 follow-up biopsy. A total of 1,056 (91%) had Gleason 3+3 and 106 (9%) 3+4. Patients with Gleason 3+4 had lower progression-free survival (20% vs 40%, p<0.01) by any biopsy criteria and treatment-free survival (52% vs 64%, p<0.01) at 5 years. Patients diagnosed with Gleason 3+3 who upgraded were at higher risk for treatment at 5 years than those with 3+4 and no upgrade (57% vs 37%, p<0.01). Risk factors for biopsy progression were initial Gleason 3+4 pathology (HR 1.4 95% CI 1.0-1.8) and PSAD (HR 1.7 95% CI 1.5-2.0), while total number of biopsies was associated with a lower risk (HR 0.7 95% CI 0.7-0.8). PSAD was a risk factor for treatment (HR 1.9 95% CI 1.6-2.3) while total biopsies (HR 0.6 95% CI 0.6-0.7) was associated with a lower risk. Among 333 men who underwent delayed RP, there was no significant difference between diagnostic 3+4 versus 3+3 in recurrence-free survival at 3 years (80% vs 90%, p=0.23). Gleason 3+4 at diagnosis and/or subsequent biopsy upgrade was associated with adverse pathology at RP, when controlling for age, race, PSAD, total number of biopsies and number of cores positive.

Conclusions

While Gleason 3+4 at initial biopsy is a risk factor for progression and treatment on AS and adverse pathology at RP, it is not associated with PSA relapse after RP suggesting that such patients are suitable candidates for AS. However, longer – term follow up is ongoing.

Funding

None