Editing Urethral Tumours (section)

== '''Urethral cancer''' ==

=== '''TNM Staging (AJCC 8th edition§)''' ===

* '''Primary tumour (T) (male and female)'''
** TX: Primary tumor cannot be assessed
** T0: No evidence of primary tumor
** '''Ta: Non-invasive papillary, polypoid, or verrucous carcinoma'''
** '''Tis: Carcinoma in situ'''
** '''T1: invades subepithelial connective tissue'''
** '''T2: invades'''
**# '''Corpus spongiosum OR'''
**# '''Periurethral muscle'''
** '''T3: invades'''
**# '''Corpus cavernosum''' '''OR'''
**# '''Anterior vagina'''
** '''T4: invades other adjacent organs (e.g. invasion of bladder wall)'''
* '''Urothelial carcinoma of the prostate'''
** '''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 periprostatic fat or bladder neck (extraprostatic extension)
** '''pT4''': invasion of adjacent organs (example: bladder wall, rectal wall)
* '''Regional lymph nodes (N) (similar to bladder)'''
** Nx: lymph nodes cannot be assessed
** N0: no lymph node metastasis
** N1: single regional lymph node in the true pelvis
*** True pelvis lymph nodes (5)
***# Perivesical
***# Obturator
***# Internal iliac (hypogastric)
***# External iliac
***# Presacral lymph nodes
** N2: multiple regional lymph node metastases in the true pelvic
** N3: lymph node metastasis to the common iliac lymph nodes
* Distant metastasis (M)
** MX: Presence of distant metastasis cannot be assessed
** M0: No distant metastasis
** M1: Distant metastasis

=== '''Male urethral cancer''' ===

==== Epidemiology ====

* Rare
* Usually presents in the 5th decade of life

==== '''Pathogenesis''' ====

* '''Risk factors for male urethral cancer (3):'''

# '''Chronic inflammation''' resulting from a history of frequent sexually transmitted diseases, urethritis
# '''Urethral stricture'''
# '''HPV subtype 16 for squamous cell carcinoma of the urethra'''

==== Natural history ====

* Can spread by
** Direct extension to adjacent structures
*** Usually involving the vascular spaces of the corpus spongiosum and the periurethral tissues
** Lymphatic dissemination to regional lymph nodes
** Hematogenous dissemination
*** Uncommon except in advanced disease

==== '''Lymphatic drainage of male urethra''' ====

* '''Anterior urethra drains into the (3):'''
*# '''Superficial inguinal lymph nodes'''
*# '''Deep inguinal lymph nodes'''
*# '''External iliac lymph nodes (occasionally)'''
* '''Posterior urethra'''
** '''Drains into the (1):'''
*** '''Pelvic lymph nodes'''
***# Perivesical
***# Obturator
***# Internal iliac (hypogastric)
***# External iliac
***# Presacral lymph nodes

==== '''Tumour Location''' ====

# '''Bulbomembranous urethra (most commonly involved, 60%)'''
# '''Penile urethra (30%)'''
# '''Prostatic urethra (10%)'''
#* See Urothelial Carcinoma of the Prostate Chapter Notes

==== '''Pathology''' ====

* '''Most common (≈80%) histology overall is urothelial carcinoma'''
** '''Squamous cell carcinoma in ≈10%'''
** '''Adenocarcinoma in 5%'''
** '''Other histologies in 5%'''
* '''The histologic subtype of urethral cancer varies by anatomic location''' (related to cell lining of that part of the urethra):
** '''Bulbomembranous urethra: 80% squamous''', 10% urothelial, 10% adenocarcinoma or undifferentiated
** '''Penile urethra: 90% squamous''', 10% urothelial
** '''Prostatic urethra: 90% urothelial''', 10% squamous

==== '''Diagnosis and Evaluation''' ====

* '''UrologySchool.com Summary'''
** '''H+P'''
** '''Imaging'''
*** '''Primary: MRI'''
*** '''Metastases:'''
**** '''Regional: CT abdomen/pelvis'''
**** '''Distant: CT chest'''
** '''Other'''
*** '''Cystoscopy with biopsy'''
* '''History and Physical Exam'''
** '''History'''
*** '''Usually delayed presentation; 96% are symptomatic at presentation'''
*** '''Most common presenting symptoms: urethral bleeding, palpable urethral mass, and voiding LUTS'''
** '''Physical Exam'''
*** '''Bimanual palpation of the external genitalia examination under anesthesia, urethra, rectum, and perineum, aids in evaluating the extent of local involvement by tumor'''
**** If rectal involvement is suspected on bimanual examination or by the patient’s symptoms, an evaluation of the lower colon by barium enema study and flexible sigmoidoscopy is recommended to assist with surgical planning
*** '''Palpable inguinal lymph nodes occur in ≈20-30% of cases and almost always represent metastatic disease, in contrast to penile cancer, in which a large percentage of palpable nodes may be inflammatory'''
* '''Laboratory'''
** '''Voided urine cytology is not reliable for diagnosis of primary urethral carcinoma'''
* '''Imaging'''
** '''CT scan of the chest, abdomen, and pelvis (or in some cases by MRI) to evaluate local soft tissue involvement, lymph node involvement, bone extension, and the presence of distant metastatic disease'''
*** '''MRI is the most sensitive staging modality for the assessment of local tumor extent;''' may be particularly helpful for detecting invasion of the corpora cavernosa
* '''Other'''
** '''Cystoscopy and transurethral or needle biopsy of the lesion is performed'''

==== Management ====

* '''Surgical excision is the primary form of treatment'''
* '''Depends on the tumour location and clinical stage'''
* '''Anterior urethra'''
** '''In general, more amenable to surgical control and better prognosis than posterior urethral carcinoma, which is often associated with extensive local invasion and distant metastasis'''
** '''Carcinoma of the Penile Urethra'''
*** '''Superficial, papillary, or low-grade tumors'''
**** '''Options (3):'''
****# '''Transurethral resection'''
****# '''Local excision'''
****# '''Distal urethrectomy and perineal urethrostomy'''
*** '''In patients with invasive disease'''
**** '''Localized to the distal half of the penis, partial penectomy with a 2-cm negative margin remains the traditional treatment for pT2 tumors (infiltrating the corpus spongiosum)'''
***** Excellent local control after this procedure has been documented
***** '''For patients with invasive anterior urethral cancer with the intent of genital preservation, chemoradiation has been reported as an option'''
**** '''Extending to or involving the proximal penile urethra, total penectomy is required to obtain an adequate margin of excision'''
*** '''Inguinal lymphadenectomy in penile urethral carcinoma'''
**** '''Non-palpable (cN0): not recommended'''
***** '''Unlike penile cancer with high-risk features, survival benefit from prophylactic inguinal lymph node dissection in patients without palpable inguinal nodes has not been demonstrated with urethral cancer'''
**** '''Palpable (cN+ [, resectable]): recommended'''
***** Cases of cure with limited nodal disease have been reported and therefore inguinal lymphadenectomy should be considered in the presence of palpable inguinal lymph nodes.
** '''Carcinoma of the Bulbomembranous Urethra'''
*** '''Radical cystoprostatectomy, pelvic lymphadenectomy, and total penectomy are often required'''
**** '''Poor survival''' has been recorded for all forms of treatment, but radical excision continues to be an important component of treatment in some patients.
*** Summary of steps:
**** Position: low lithotomy to allow perineal access.
**** [Further details in Campbell’s]
*** '''Because of the relatively poor outcomes after surgery alone for advanced tumors of the posterior urethra, multimodal therapy in this setting is increasing'''
**** '''Squamous cell cancers respond poorly to the M-VAC regimen''' [SASP]
* '''Posterior Urethra'''
** '''Carcinoma of the Prostatic Urethra'''
*** See Urothelial Carcinoma of the Prostate Chapter Notes
** '''Management of the urethra after cystectomy'''
*** '''Timing of urethral recurrence post-cystectomy'''
**** ≈40% of urethral recurrences are diagnosed within 1 year after cystoprostatectomy, with a median time to diagnosis of 18 months
**** Late urethral recurrence have been reported, indicating the need for prolonged surveillance in these patients
*** '''Diagnosis and Evaluation'''
**** '''After non-orthotopic diversion, urethral wash cytology has traditionally been recommended and leads to earlier diagnosis of urethral recurrence than when evaluation is delayed until symptoms occur'''
**** '''After orthotopic, diversion, voided urine cytology is part of standard surveillance'''
**** '''Patients with positive results for urine or urethral wash cytology or symptoms of urethral bleeding, discharge, or palpable mass are evaluated with cystoscopy and biopsy.'''
***** '''Pelvic CT or MRI may be necessary to aid in assessment of the local extent of larger invasive tumors and to assess for metastatic disease'''.
**** '''Management'''
***** '''Patients who develop urethral carcinoma in situ after orthotopic diversion may respond to urethral perfusion with BCG, but this treatment is ineffective for those with papillary or invasive disease and these patients may require urethrectomy'''
***** '''When a delayed urethrectomy is performed in a male patient after radical cystectomy, it is important to remove the fossa navicularis and urethral meatus''' because of the high incidence of involvement of the squamous epithelium
***** '''Total urethrectomy after cutaneous diversion'''
****** Technique: The high or exaggerated lithotomy position provides optimal exposure for total urethrectomy, with the hips and knees gently flexed and the lower limbs abducted in boot-type stirrups. [Further detail’s in Campbell’s]
***** '''Total urethrectomy after orthotopic diversion'''
****** Technique: Total urethrectomy after orthotopic urinary diversion is performed through an abdominoperineal approach [Further detail’s in Campbell’s]
****** In most situations, urinary diversion is accomplished with an ileal conduit