27 - Cancer of Urethra and Penis

Authors: Macfarlane, Michael T.

Title: Urology, 4th Edition

Copyright 2006 Lippincott Williams & Wilkins

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Chapter 27

Cancer of Urethra and Penis

Cancer of Urethra

Primary cancer of the urethra is an uncommon disease. It is the only urologic cancer that occurs more frequently in females than in males. Squamous cell carcinoma (SCC) represents the most common histologic type (80%); however, transitional cell carcinoma (15%), adenocarcinoma (5%), and, rarely, melanoma, also occur. Risk factors for the development of this tumor are chronic irritation and infection. Spread is primarily by direct extension to adjacent structures. Despite its tendency to remain localized, this is a disease with a poor prognosis, generally because it is found late in most cases. Lesions of the distal urethra have a better prognosis than do more proximal ones. A high index of suspicion is the key to diagnosis.

Cancer of Male Urethra

Urethral carcinoma in the male patient is associated with chronic inflammation, sexually transmitted disease, and strictures in the bulbomembranous portion of the urethra. Patients present with obstructive symptoms, recurrent strictures, a history of venereal disease, hematuria, or a sensation of a mass in the perineum. Spread is by direct extension to adjacent structures. Primary therapy is surgical excision.

Cancer of Female Urethra

Urethral carcinoma in the female patient is often found in the setting of urethral diverticula. Bleeding, dysuria, frequency, perineal pain, and dyspareunia are common presenting complaints. Most of these tumors are locally advanced when detected and involve the proximal urethra. Small distal tumors may respond well with radiation therapy or surgical excision alone.

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Workup

The diagnosis is made by urethrography, urethroscopy, and repeated biopsy of the involved area. Staging is obtained by bimanual examination, magnetic resonance imaging, and computed tomography scan of chest, abdomen, and pelvis. In general, anterior or distal urethral tumors drain to the inguinal nodes, whereas posterior tumors drain to the pelvic nodes (i.e., obturator, presacral, and internal and external iliac nodes). Unlike those in cancer of the penis, clinically enlarged inguinal nodes usually imply metastatic disease and not benign inflammation. Tumor node metastasis (TNM) staging should be used.

Treatment

Unfortunately, the prognosis is poor for squamous carcinoma of the urethra despite radical surgery. Radiation and chemotherapy have little to offer these patients. Proximal tumors will usually require cystectomy and urethrectomy.

Cancer of Penis

Penile cancer is an uncommon disease (0.5% of malignancies in men in the United States) that occurs more frequently in older men. It has been associated with chronic inflammatory disease, venereal disease, human papilloma virus infection, and phimosis. Circumcision appears to be protective against the development of cancer of the penis. It occurs most frequently on the glans (50%), coronal sulcus, and prepuce (20%). More than 95% of cases are SCC. Hematogenous spread is rare; rather, an orderly spread via the lymphatics is the rule. Lymphatic spread is first to the superficial and deep inguinal nodes and then to the iliac nodes. The sentinel lymph node (located near the pubic tubercle and superficial epigastric vein) is believed to be the first point of lymphatic drainage for the penis. Patients often delay seeking medical attention and usually present with complaint of a nodular, ulcerative, or fungating penile lesion.

Carcinoma in Situ of the Penis

SCC in situ of the penis, also known as erythroplasia of Queyrat and Bowen's disease, can present as solitary painful or pruritic lesions of the penis. Erythroplasia of Queyrat is a velvety, erythematous

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lesion of the glans penis associated with burning and itching. Bowen's disease is a crusted or ulcerated plaque of the skin on the shaft of the penis. Diagnosis is made histologically, and treatment involves destroying the lesions with topical agents, cryotherapy, lasers, radiation, or surgery.

Workup

The definitive diagnosis of penile cancer is made only by histologic examination of a full-thickness biopsy. The tumor grade, depth of invasion, and configuration are important in planning management. Physical examination should include rectal and bimanual examination and inguinal palpation for adenopathy. A false-positive rate of up to 50% has been noted for clinically palpable inguinal nodes in penile cancer. Node enlargement secondary to inflammation is common; therefore, a short course of antibiotics (2 3 weeks) is recommended to help differentiate the true-positive nodes. Further staging includes chest radiograph, liver function tests, magnetic resonance imaging of the penis, ultrasound of inguinal nodes, and pelvic computed tomography scan. TNM staging should be used.

Treatment

Primary Neoplasm

The primary neoplasm is generally best treated by wide surgical excision leaving adequate tumor-free margins. Lesions confined to the prepuce can be managed with circumcision. Small Tis, Ta, and perhaps T1 lesions of the glans can be managed with laser therapy or Mohs micrographic surgery (MMS). Tumors confined to the glans or distal shaft will require partial amputation and reconstruction. Involvement of the proximal shaft or base of the penis necessitates total penectomy. In more advanced tumors, hemipelvectomy or hemicorporectomy is occasionally considered. Options for patients with carcinoma in situ (erythroplasia of Queyrat or Bowen's disease) include local excision, fulguration, radiation, lasers, or chemotherapy with topical (5%) 5-fluorouracil.

Inguinal Lymph Nodes

Clinically Positive Inguinal Examination

The presence of positive lymph node metastases portends a markedly worse prognosis. Palpable inguinal lymph nodes 4 to 6 weeks after control of the primary tumor and antibiotic therapy should be managed with lymphadenectomy. Bilateral inguinal

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lymphadenectomy is a therapeutic procedure conferring a 20% to 50% 5-year disease-free survival on patients with positive nodes compared with almost certain death if untreated.

Clinically Negative Inguinal Examination

Prophylactic inguinal lymphadenectomy is a highly morbid procedure with complications of thrombophlebitis, pulmonary embolism, wound infection, and lymphedema. However, clinical inguinal examination has a 2% to 25% false-negative rate. Patients with negative inguinal examinations should probably undergo lymphadenectomy in the setting of high-grade or invasive-stage (T2 or T3 N0M0) primary tumor. If superficial nodes are positive on frozen sections, then a complete therapeutic inguinal lymphadenectomy should be performed. Patients with low-grade, low-stage (Tis, Ta, T1 N0M0) tumors and negative inguinal examinations should undergo close surveillance for at least 2 to 3 years and be taught careful self-examination of the inguinal areas.

Pelvic Lymph Nodes

Pelvic lymphadenectomy is generally recommended only in healthy young individuals with positive inguinal nodes. The therapeutic benefit of pelvic node dissection has not been proven.

Advanced Inoperable Tumor (Jackson Stage IV)

Treatment is generally palliative chemotherapy or radiotherapy with aggressive combined-modality therapy, with chemotherapy and surgery reserved for the young patient.

Verrucous Carcinoma of Penis

Verrucous carcinoma of the penis is a peculiar slow-growing low-grade tumor that invades locally, destroying adjacent tissues by compression but shows no signs of malignant change on histologic examination and rarely metastasizes. It is sometimes classified as a variant of SCC that composes 5% to 15% of penile cancers. However, its correct classification is unclear. It is also referred to as a Buschke-Lowenstein tumor and giant condyloma acuminatum because of its similar gross appearance. Deep biopsies are required to make the histologic diagnosis and to examine for evidence of invasion, the hallmark of SCC. Wide surgical excision is the treatment of choice. Groin dissection is not necessary because lymph node metastases are rare. Radiotherapy is ineffective and should be avoided because it may transform the carcinoma into an aggressive metastasizing tumor.