Editing Urothelial Cancer of the Prostate

== Background ==

* '''90% of cases of urothelial carcinoma of the prostate occur in patients with a history of urothelial cancer of the bladder, primarily bladder carcinoma in situ (CIS)'''
** '''However, only 3% patients with primary urothelial cancer of the bladder develop prostatic urothelial carcinoma'''
*** '''In males undergoing radical cystectomy for urothelial cancer, 40% will be found to have urothelial carcinoma of the prostate'''
**** '''In patients undergoing cystectomy for bladder cancer, extension of the tumor into the prostatic urethra without stromal invasion does not carry an adverse prognosis'''
* '''Primary urothelial carcinoma of the prostate without bladder involvement is''' '''uncommon, accounting for 1-4% of all prostate carcinomas'''

== Pathophysiology ==

* Most patients with urothelial carcinoma of the prostatic ducts and acini will have direct extension of the bladder cancer into the prostatic urethra; however, some patients will have pagetoid spread underneath normal-appearing urothelium at the bladder neck
** Intraductal and infiltrating urothelial carcinoma involving the prostate tends to be seen in higher-stage bladder tumors

* '''Risk factors for prostatic urethral involvement include (5):'''
*# '''Presence of bladder CIS'''
*# '''Previous intravesical chemotherapy'''
*# '''Multi-focal disease'''
*# '''Tumours at the trigone or bladder neck'''
*# '''High-risk NMIBC'''

== '''TNM staging of Urethral Carcinoma (AJCC 8th edition§)''' ==

=== '''Prostatic urethra''' ===

* '''pTX''': cannot be assessed
* '''pT0''': no evidence of primary tumor
* '''pTa''': non-invasive papillary carcinoma
* '''pTis: carcinoma in situ of the prostatic urethra, periurethra or ducts'''
** '''Tis pu: Carcinoma in situ, involvement of prostatic urethra'''
** '''Tis pd: Carcinoma in situ, involvement of prostatic ducts'''
* '''pT1:''' invasion of prostatic urethral '''subepithelial connective tissue'''
* '''pT2: invasion of prostatic stroma'''
** '''In the bladder cancer TNM staging system, only patients with prostatic stromal invasion, either direct or indirect, are considered to have T4a-staged bladder cancer disease'''
** '''Extension of the tumor into the prostatic urethra without stromal invasion is currently classified under the prostatic urethral section, not bladder'''
* '''pT3''': '''invasion of peri-prostatic fat or bladder neck (extraprostatic extension)'''
* '''pT4''': invasion of adjacent organs (example: bladder wall, rectal wall)

=== '''Penile urethra''' ===

* '''pTX''': cannot be assessed
* '''pT0''': no evidence of primary tumor
* '''pTa''': noninvasive papillary carcinoma
* '''pTis''': carcinoma in situ
* '''pT1''': invasion of urethral subepithelial connective tissue
* '''pT2''': invasion of corpus spongiosum
* '''pT3''': invasion of corpus cavernosum
* '''pT4''': invasion of adjacent organs (example: bladder wall)

== Diagnosis and Evaluation ==

* '''Transurethral resection of the prostatic urethra'''
** '''Primary method for detecting prostatic urethral carcinoma'''
*** '''For highest yield, prostatic urethral biopsies should include any suspicious area, as well as at 5 and 7 o’clock (precollicular area) especially at the level of the verumontanum''', as this area contains the highest concentration of prostatic ducts
** '''Indications:'''
**# '''Positive urine cytology but a negative bladder biopsy'''
**# '''Recurrent bladder cancer after multiple courses of intravesical chemotherapy'''
**# '''Visible tumour in prostatic urethra'''

== Management ==

* '''Based on the degree or depth of involvement'''
** '''See 2015 CUA NMIBC Guideline Notes'''
*** '''pTis pu (CIS of the prostatic urethra) or visible prostatic urethra tumour concomitant with NMIBC of the bladder: TURP then BCG.'''
**** BCG is given after TURP for accurate staging and increasing efficacy by increasing surface area
*** '''pTis pd (CIS involving the prostatic ducts): treatment controversial, consider TURP + BCG'''
**** Despite good response to BCG, prostatic ductal involvement has potential for invasion, and if invasion occurs there is a high risk of metastasis.
*** '''Re-biopsy of the prostatic urethra is recommended after BCG to detect recurrences early'''
**** '''Recurrence of any HG lesion in prostatic urethra after TURP + BCG: consider radical cystectomy plus urethrectomy'''
***** If patient prefers bladder-sparing approach, consider repeat BCG or intra-vesical gemcitabine
*** '''pT2 (prostatic stromal invasion (pT2): radical cystectomy +/- urethrectomy'''
**** '''Consideration of urethrectomy should be made, especially if tumor is present near or at the surgical margin'''
** Campbell’s:
*** For patients with non-invasive prostatic urethral cancer, TURP with BCG therapy is appropriate. For patients with prostatic ductal disease, complete TURP is warranted, plus BCG therapy
*** Prostatic stromal invasion is a poor prognostic factor and is treated with multimodal therapy combining chemotherapy and radical cystectomy

== Prognosis ==

* 5-year survival varies by stage: up to 100% for those with urethral mucosal involvement; 50% with ductal/acinar/glandular involvement; and 40% with stromal invasion

== Questions ==

# What are the risk factors for urothelial carcinoma of the prostate?
# What is the pT staging of a patient found to have bladder cancer invading the prostatic stroma?

== Answers ==

# What are the risk factors for urothelial carcinoma of the prostate?
## Presence of bladder CIS
## Previous intravesical chemotherapy
## Multifocal disease
## Tumours at the trigone or bladder neck
## High-risk NMIBC
# pT4a

== References ==

* Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 92