Is sparing the prostate still considered radical cystectomy? The case against prostate-sparing cystectomy for bladder cancer

Abstract

Radical cystoprostatectomy with bilateral pelvic lymphadenectomy and urinary diversion remains the gold standard therapy for localized bladder cancer in men.1 The procedure has been refined over several decades with the current application of nerve-sparing techniques.2,3 Unfortunately, the procedure carries significant risks of urinary and sexual dysfunction resulting in bladder-sparing approaches being popularized for selected early invasive bladder cancers. More recently, some authors have suggested that prostate-sparing cystectomy may be appropriate in selected men to improve postoperative sexual and urinary function.4–6 They propose that leaving the prostate, or part of it, intact will result in less damage to pelvic innervation and better preservation of sexual function and urinary sphincter control in cases of orthotopic diversion. These potential functional improvements must be weighed against any risks for oncologic outcomes. One potential oncologic pitfall is the assumption that the prostate does not harbour transitional cell carcinoma (TCC) of the bladder. The incidence of occult prostatic involvement with TCC in patients undergoing radical cystectomy ranges between 20% and 48%,7–9 raising significant concern about sparing the prostate. In a large study, Pettus and colleagues10 concluded that patients with tumours involving the trigone and bladder neck or associated carcinoma in situ of the bladder should be considered at high risk for developing prostatic urethral carcinoma. Moreover, the absence of these factors did not conclusively rule out the presence of carcinoma in the prostatic urethra. Another significant risk is the potential for prostatic adenocarcinoma. Many argue that prostate cancer is not a major problem in this population, since men undergoing cystectomy for invasive bladder cancer are often elderly, with a poor prognosis for their bladder cancer. However, prostate-sparing surgery is usually offered to men whose pelvic disease is not advanced and in whom sexual function is normal, thus younger men. It is precisely in these younger men with early forms of invasive bladder cancer that occult prostate cancer could pose problems in the future. Occult prostate cancer has a reported incidence of 23% to 47% in men undergoing radical cystectomy. Furthermore, about 50% of these cancers are potentially significant based on histologic criteria.11–14 Revelo and colleagues11 detected that 41% of cases had unsuspected prostatic cancer, of which 48% were clinically significant and 16% were extracapsular. Of importance, 60% involved the apex, including 79% of significant cases, suggesting that recommending apical sparing as a compromise could potentially be equally hazardous. These findings were confirmed by another study in which 27% of patients undergoing cystectomy for invasive TCC of the bladder were found to have prostatic carcinoma (PCa), with 33% involving the apex of the prostate.15 The authors suggested that the high likelihood of apical prostate cancer requires careful excision of the apical margins. Kablain and colleagues13 previously reported that 38% of patients undergoing cystectomy for bladder cancer and who harbour prostate carcinoma had a distinct apical predominance of the tumours. In a recent study, Hautmann and colleagues16 addressed the probability of overlooking clinically significant prostate cancer using sextant biopsy. They analyzed specimens from 133 consecutive patients undergoing cystoprostatectomy for bladder cancer. Patients were included in the study if they had serum prostate-specific antigen (PSA) 25%. Systematic sextant biopsy was performed in the operating room immediately following cystoprostatectomy and prostates were subsequently step-sectioned (3 mm). The threshold defined to distinguish between significant and insignificant cancer was 0.5 cm3. Incidental prostatic cancer was found in 58 of the 133 bladder cancer patients (44%), with presence of significant cancer in many. Sextant biopsy detected 7 cancers, including 4 of 47 (9%) that were insignificant and 3 of 11 (27%) that were significant. Thus, sextant biopsy missed 8 (73%) of 11 of significant prostate cancers. These data suggest that despite careful screening for prostate cancer for cystoprostatectomy patients, it remains regularly overlooked in a significant proportion of clinically relevant cases. In a recent prospective study by Saad and colleagues,17 425 men had radical cystoprostatectomy for invasive bladder cancer and entire mounted prostates were step-sectioned at 2 to 3 mm intervals. Of 425 cases examined, there was histological evidence of prostatic adenocarcinoma in 90 cases (21.2%). Prostatic TCC was found in 66 patients (15.6%). There was also significant benign prostatic hyperplasia in 175 (41.2%). They concluded that the marginal reported functional advantage of prostate-sparing cystectomy is not worth the potential oncological risks. In a prospective study, Koraitim and colleagues18 studied urinary continence and voiding differences between men undergoing classic radical cystoprostatectomy and men with prostate-sparing cystectomy. They found no statistical difference between both groups with respect to urinary continence, but found a significant difference in peak flow rate. They concluded that preservation of prostatic apex may present an element obstructing the evacuation of ileal bladders.