Urethral Cancer: An Overview

Epidemiology

Urethral cancer is an extremely rare lesion, with fewer than 2000 reported cases. Urethral cancer comprises <1% of the total incidence of malignancies. Because many medical centers see only a few cases over many years, not enough data are available from large series to dictate the best-accepted treatment. A Surveillance, Epidemiology, and End Results (SEER) study reported an incidence of 4.3 per million in males and 1.5 per million in females. Although the female urethra is much shorter than its male counterpart, primary urethral carcinoma was in the past believed to be much more common in women than in men. The ratio of female to male predominance was reported as 4:1, and female urethral carcinoma was the only urologic malignant neoplasm that was believed to be more common in women than in men. Female urethral carcinoma is among the rarest neoplasias of the genitourinary tract and corresponds to .003% of all malignant neoplasias occurring in the female urogenital tract. Although once believed that urethral cancer was four times more common in women than men, recent literature suggests that primary urethral cancer is nearly three times more common in males. Cancer of the male urethra was first reported by Thiaudierre in 1834. Two large series have been reported, including one of 230 patients by McCrea and Furlong, and the other by Kaplan et al describing 232 cases. Cancer of the female urethra was first reported by Wasserman in 1895. The incidence increases with age; an incidence of 32 per million and 9.5 per million was found in males and females aged 75–84 years, respectively. Primary urethral cancer was found to be twice as likely in African Americans as in Whites.

Abstract

Urethral cancer is an extremely rare lesion, with fewer than 2000 reported cases. Although once believed that urethral cancer was four times more common in women than men, recent literature suggests that primary urethral cancer is nearly three times more common in males. Fifty-five percent of primary urethral are transitional cell carcinomas, 21.5% and 16.4% being squamous cell carcinomas and adenocarcinomas, respectively. The signs and symptoms of urethral cancer vary and are neither diagnostic nor pathognomonic. The main prognostic factors for these tumors are age, stage, grade, systemic metastases, histological type, site, size, and the presence of pelvic lymph node extension. As with most tumors, early detection affords the best chance of cure. Cystourethroscopy and biopsy of the lesion helps to determine the diagnosis and histological subtype. The magnetic resonance imaging (MRI) of the pelvis is the test of choice for clinical staging and provides reliable data on tumor extent and local invasion. Urethral carcinoma can spread by direct extension to adjacent structures, usually involving the vascular spaces of the corpus spongiosum and the periurethral tissues, vagina, bladder neck, rectum, or it can metastasize through lymphatic embolization to regional lymph nodes. Hematogenous dissemination is uncommon except in advanced disease. Little progress has been made regarding the definitive treatment options due to its low incidence and subtle clinical findings. The primary form of treatment for urethral carcinoma is surgical excision. Multimodality therapy appears to be the mainstay treatment to achieve the longest survival without evidence of disease. Patients who survived the longest without disease received combination therapy that consisted of either chemotherapy with radiotherapy or neoadjuvant chemotherapy with radiotherapy prior to surgery.

Keywords

urethral cancer, clinical presentation, investigations, management