Radiation Oncology/Urethra

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Urethra - includes urothelial (transitional cell) carcinoma of the prostate

Epidemiology[edit]

  • Male urethral CA occurs in 40's
  • Female urethral CA occurs in pts >50.
  • F>M 4:1

Anatomy[edit]

Male Urethra

  • Runs from bladder neck to glans penis.
  • Anterior Urethra includes glandular, penile, and bulbous urethra.
  • Posterior Urethra includes membranous and prostatic urethra.

Female Urethra

  • Mostly buried in anterior wall of vagina.
  • Proximal Urethra includes proximal 2/3 of urethra.
  • Distal Urethra includes distal 1/3 of urethra.

Nodal drainage

  • Anterior urethra drains to superficial and deep inguinal nodes.
  • Posterior urethra drains to pelvic nodes (ext iliac, hypogastric, obturator).

Sites of disease

  • Most common site of disease in males is bulbomembranous urethra.
  • Most common site of disease in females is near meatus.

Staging[edit]

AJCC Staging (7th edition, 2009)[edit]

T-stage (Male and Female)

  • Ta - non-invasive papillary, polypoid, or verrucous carcinoma
  • Tis - carcinoma in situ
  • T1 - invades subepithelial connective tissue
  • T2 - invades any of the following: corpus spongiosum, prostate, periurethral muscle
  • T3 - invades any of the following: corpus cavernosum, beyond prostatic capsule, anterior vagina, bladder neck
  • T4 - invades other adjacent organs

T-stage - Urothelial (transitional cell) carcinoma of the prostate:

  • Tis (pu) - in situ, involvement of the prostatic urethra
  • Tis (Pd) - in situ, involvement of the prostatic ducts
  • T1 - invades subepithelial connective tissue
  • T2 - invades any of the following: prostatic stroma, corpus spongiosum, periurethral muscle
  • T3 - invades any of the following: corpus cavernosum, beyond prostatic capsule, bladder neck (extraprostatic extension)
  • T4 - invades other adjacent organs (invasion of the bladder)

N-stage:

  • N0 - none
  • N1 - single lymph node 2 cm or less
  • N2 - single lymph node > 2 cm, or multiple nodes

M-stage:

  • M0 - no
  • M1 - yes

Overall stage:

  • I - T1 N0
  • II - T2 N0
  • III - T3 or N1
  • IV - T4 or N2 or M1

Prempree Staging[edit]

for carcinoma of female urethra

  • Prempree Stage I - distal 1/2 urethra
  • Prempree Stage II - entire urethra, peri-urethral tissues; no vulvar or bladder neck involvement
  • Prempree Stage IIIA - urethra + vulva
  • Prempree Stage IIIB - vaginal mucosa
  • Prempree Stage IIIC - urethra + bladder neck
  • Prempree Stage IVA - parametrium or paracolpium
  • Prempree Stage IVB - +nodes or distant mets

Treatment of Female Urethral Cancer[edit]

  • Small lesions (<4cm) can be treated w/ brachytherapy alone.
  • Larger lesions are treated with combination of external beam radiation and brachytherapy.

Definitive Radiation[edit]

  • Mallinckrodt (1959-95) PMID 9635699 -- Grigsby PW. "Carcinoma of the urethra in women," Int J Radiat Oncol Biol Phys. 1998 Jun 1;41(3):535-41.
    • 44 women w/ carcinoma of the urethra. T1-T4. Median FU time 8.25 yrs. Tx w/ surgery in 7, xrt in 25, surg + xrt in 12.
    • 5yr OS 42%, 5yr CSS 40%
    • Tumor size (>4cm) and histology (adenoCA) were poor prognostic factors on multi-variate analysis. Tumor location not prognostic.
  • Princess Margaret (1961-90) PMID 10869752 -- Milosevic MF. "Urethral carcinoma in women: results of treatment with primary radiotherapy," Radiother Oncol. 2000 Jul;56(1):29-35.
    • 34 women w/ primary urethral CA (stage I-IV) tx'd w/ xrt; xrt fields included to tumor only, to tumor + nodes, and w/ interstitial brachytherapy.
    • 7yr OS 41%, 7yr CSS 45%
    • Benefit of brachytherapy seen most in pts w/ bulky tumor. Large tumor size only independent predictor of dz recurrence.
  • M.D. Anderson (1955-89) PMID 8490839 -- Garden AS. "Primary carcinoma of the female urethra. Results of radiation therapy." Cancer. 1993 May 15;71(10):3102-8.
    • 97 pts w/ primary urethral CA tx'd w/ xrt
    • 5yr OS 41%, 10yr OS 31%, 64% local control at 5 yrs w/ xrt alone.
    • 49% of those whose dz was controlled locally had symptomatic complications (urethral stenosis, fistula, necrosis)

Treatment of Male Urethral Cancer[edit]

  • Standard treatment option for T1-T3 disease remains surgical (amputation or partial amputation).
  • Distal lesions have been treated curatively with definitive xrt w/ doses >70 Gy.

Surgery[edit]

  • MSKCC (1958-96) PMID 10367840 -- Dalbagni G et al. "Male urethral carcinoma: analysis of treatment outcome." Urology. 1999 Jun;53(6):1126-32.
    • 46 pts w/ primary CA of bulbar/anterior urethra. 78% w/ locally advanced dz. External beam xrt used as part of salvage for locally recurrent.
    • 5 yr OS 42%
  • M.D. Anderson (1979-90) PMID 8154072 -- Dinney CP et al. "Therapy and prognosis for male anterior urethral carcinoma: an update." Urology. 1994 Apr;43(4):506-14.
    • 23 pts tx'd w/ primary urethral CA
    • Tumors of fossa navicularis and penile urethra could be tx'd w/ distal urethrectomy/partial penectomy.
    • Tumors of bulbomembranous urethra best tx'd w/ en bloc excision of penis, scrotum, prostate, bladder.
  • St. George's Hospital, UK PMID 17488307 -- Smith Y et al. "Penile-preserving surgery for male distal urethral carcinoma." BJU Int. 2007 May 4
    • 18 consecutive pts w/ distal urethral CA tx'd w/ penile-preserving surgery; median FU 26 mo's
    • No local recurrences, but 4 w/ regional nodal dz progressed.

Chemoradiation[edit]

  • Lahey Clinic PMID 8944514 -- Oberfield RA et al. "Management of invasive squamous cell carcinoma of the bulbomembranous male urethra with co-ordinated chemo-radiotherapy and genital preservation." Br J Urol. 1996 Oct;78(4):573-8.
    • Suprapubic urinary diversion followed by 45 Gy in 25 fx to penis, perineum, regional lymphatics w/ concurrent Mitomycin C and 5FU.
  • UPDATE at AUA 2005 (Medscape Review):
    • 14 pts tx'd from 1991-2004. T2-4 dz in distal or bulbomembranous urethra.
    • 12/14 locally controlled. 1 pt died of metastatic dz. Urethral stricture common, often requiring urethral reconstruction.