Is a positive bladder neck margin truly a T4 lesion in the prostate specific antigen era? Results from the SEARCH...

Positive bladder neck margins after radical prostatectomy are currently designated as pT4 lesions. However, to our knowledge the prognostic significance of a positive bladder neck margin in the prostate specific antigen era is unknown. We examined the association between positive bladder neck margins and prostate specific antigen recurrence relative to other pathological findings.

We examined 1,722 men from the Shared Equal Access Research Cancer Hospital Database who were treated with radical prostatectomy without lymph node metastases. Time to prostate specific antigen recurrence was compared in men with positive vs negative bladder neck margins using Cox proportional hazards models adjusted for multiple clinical and pathological features.

A positive bladder neck margin in 79 patients (5%) was significantly associated with other poor prognostic features, including higher prostate specific antigen, higher pathological Gleason sum, extracapsular extension, seminal vesicle invasion and other positive margins. After adjusting for clinical and pathological characteristics positive bladder neck margins were associated with an increased risk of prostate specific antigen recurrence (HR 1.52, 95% CI 1.06-2.19, p = 0.02). Relative to organ confined margin negative disease a positive bladder neck margin associated with other positive margins showed a recurrence risk that was similar to that of seminal vesicle invasion (HR 4.14, 95% CI 2.55-6.73 and HR 4.22, 95% CI 3.08-5.78, respectively, each p <0.001). An isolated positive bladder neck margin was a rare event, noted in 15 patients (0.7%). In these men the recurrence risk was difficult to estimate due to the small number. However, the HR was similar to that in men with nonbladder neck positive margins or extracapsular extension (HR 2.65, 95% CI 0.97-7.25, p = 0.06 and HR 2.19, 95% CI 1.71-2.82, p <0.001, respectively).

In the current study a positive bladder neck margin was frequently associated with other adverse features. When it was concomitant with other positive margins, a positive bladder neck margin was associated with a progression risk similar to that of seminal vesicle invasion (T3b disease). Although men with an isolated positive bladder neck margin had a more favorable pathological profile, there were too few of them to assess outcome reliably. However, the limited data suggest that they may best be categorized as having pT3a disease.