Cancer of the penis is rare in the United States (an annual incidence of 1-2 per 100,000 men, which translates into 1400 cases yearly). Of these, nearly 95% are squamous cell carcinomas. Penile cancer is most common in uncircumcised and nonwhite populations. The onset is in the fourth and fifth decades of life.
The cause of penile cancer appears to be chronic irritation. Predisposing factors include presence the foreskin (uncircumcised men), phimosis (tight opening of the foreskin), and poor hygiene. The closed space under the foreskin allows accumulation of smegma and enables chronic irritation. The risk of penile cancer can be virtually eliminated by neonatal circumcision. Delayed circumcision offers only slight protection against the subsequent development of penile carcinoma. Penile cancer is also associated with exposure to ultraviolet [UV] radiation treatment for psoriasis. There is also evidence of a relationship between penile cancer and Human Pappiloma Virus [HPV] types 16, 18, and 33: these are commonly found in women with cervical cancer.
Penile cancer usually begins as a small lesion and gradually enlarges to involve the entire penis. It may be flat and cause an ulcer. Alternatively, it may extend away from the penis with the appearance of cauliflower or broccoli. Laboratory studies are usually normal in patients with penile cancer. There is a limited role for radiologic imaging: CT and MRI scans can be helpful in patients with high grade or invasive tumors in whom spread or metastasis to the pelvic or retroperitoneal lymph nodes is suspected. A delay in seeking medical attention is very common and can result in progression to advanced disease. The course of penile cancer is relentless and most untreated patients die within 2 years.
Penile cancer metastasizes (spreads) in a predictable pattern. Metastasis is most common to the lymph nodes, especially those in the inner thigh (inguinal lymph nodes). This is followed by drainage into the pelvic lymph nodes and beyond. Metastatic deposits in the regional lymph nodes continue to enlarge if left untreated, and can cause skin necrosis, infections, and erosion into blood vessels. The risk of spread is related to the size of the initial (primary) lesion.
At time of presentation, determination should be made of the lesion’s size, location, and depth of involvement. Pathologic staging by removing the tissue remains necessary to plan appropriate management. Accurate staging is imperative for guiding treatment recommendations.
If there are suspicious (enlarged and hard) lymph nodes in the groin, antibiotics are often prescribed. If the lymph node enlargement does not disappear, then surgery may be required to remove the lymph nodes (called an ilioinguinal lymphadenectomy).
The goal of treatment is complete removal of the primary lesion with adequate margins. The standard of therapy for the primary lesion is either or partial or total penectomy (removal of the penis). Partial penectomy is currently the most standard treatment. Because of the disfigurement and psychological impact of removing all or part of the penis, other treatment options have gained increasing acceptance in the treatment of penile cancer, but must be used within their limitations. These include:
- Circumcision: In very select patients, circumcision may be adequate surgery. If the cancer is small, low grade, noninvasive, involves only the foreskin, and permits an adequate margin, complete tumor removal can often be accomplished with circumcision. However, circumcision alone is followed by a 30-50% recurrence rate. After surgery, these patients must be followed very closely.
- Moh’s Microsurgery: This is a method of surgically removing skin cancer by removing tissue in thin layers. This approach is best applied for very small distal penile lesions less than 1 cm. Following Moh’s surgery, the glans is often misshapen and meatal stenosis is common.
- Laser: Nd-YAG; This is acceptable for very rare and very superficial lesions. Although laser therapy offers the advantage of preserving the penis, the depth of laser penetration is shallow and this limits it’s application.
- Radiation Therapy: The advantage of radiation therapy is that it preserves penile anatomic structure. The disadvantages are that penile cancers are relatively resistant to radiation and there is a very high rate of complications (fistulas, strictures, edema, skin necrosis, and pain). Approximately 30-50% patients will require subsequent penectomy after attempted radiation treatment.
- Chemotherapy: There is a limited role for chemotherapy: those patients with documented spread to the lymph ndoes and other tissues. The most effective chemotherapeutic drugs are cisplatin, bleomycin, and methotrexate.
Surgery: Total and Partial Penectomy
Treatment of penile cancer must be individualized to each patient. Surgeons in the UMass Department of Urology are trained in the most up-to-date and technologically-advanced methods of treating penile cancers. At you appointment, your surgeon will be glad to discuss all treatment options with you. The mainstay treatment is removal of all or part of the penis.
- This involves removal of the end of the penis. This operation is used for penile tumors that are small and located towards the tip of the penis.
- A stump of penis is left behind through which the patient urinates and ejaculates.
- If an inadequate length of stump is left behind for urination or sexual function, the entire penis should be removed.
- Patients are followed closely for any sign of recurrence.
This operation is rarely used in conjunction with a lymph node dissection.
Radical (Total) Penectomy
- This involves removal of the entire penis and urethra (the tube through which urine exits the body). This operation is used for penile tumors that are large and located in the middle or at the base of the penis.
- This operation is also used when a partial penectomy is attempted but adequate length is not achieved.
- The urethra is redirected to the area between the scrotum and rectum (called a “perineal urethrostomy”). The patient must sit to urinate and cannot ejaculate.
- The testes are left in place so reproduction is possible, but only through surgery to harvest sperm from the testes followed by in vitro fertilization.
- Patients are followed closely for any sign of recurrence.
- This operation is often used in conjunction with a lymph node dissection.
Surgery: Lymph Node Dissection
Ilioinguinal Lymph Node Dissection
- This involves removal of the lymph nodes in the groin or thigh. This operation is used for men with either high grade invasive cancer or those who have palpable lymph nodes in their groins after taking 6 weeks of antibiotics.
- Ilioinguinal lymphadenectomy can be associated with significant side effects, such as infection, skin necrosis, wound breakdown, edema, and even a low, but finite, mortality rate. It is recommended that patients with cancer of the penis obtain treatment in an academic medical center with experience in the treatment of such tumors.