PENILE CANCER – Types, Causes and Risk Factors, Clinical Manifestations, Diagnostic Evaluations, Stages and Management
Penile cancer is a disease in which malignant (cancer) cells form in the tissues of the penis, an organ that makes up part of the male reproductive system. It is most often diagnosed in men over the age of 50. Penile cancer is rare in most developed nations, where the rate is less than 1 per 100,000 men per year
TYPES OF PENILE CANCER
There are several types of penile cancer, including:
- Epidermoid/squamous cell carcinoma: 95% of penile cancer is epidermoid, or squamous cell, carcinoma. This means that, under a microscope the cells resemble the tissues that make up skin. When cancer begins in squamous cells, it is called non-melanoma skin cancer and it can develop anywhere on the penis; most develop on or under the foreskin. When found at an early stage, epidermoid carcinoma can usually be cured.
- Basal cell penile cancer: Under the squamous cells in the lower epidermis are round cells known as basal cells. These are occasionally become cancerous. This is also called non-melanoma skin cancer. Less than 2% of penile cancers are basal cell cancers.
- Melanoma: The deepest layer of the epidermis contains scattered cells called melanocytes, which produce the melanin that gives skin color. Melanoma starts in melanocytes, and it is the most serious of the skin cancer types. This cancer occasionally occurs on the surface of the penis.
- Sarcoma: About 1% of penile cancers are sarcomas, which are cancers that develop in the tissues that support and connect the body, such as blood vessels, smooth muscle and fat.
CAUSES AND RISK FACTORS
The exact cause of cancer of the penis is unknown. Factors that are important for the development of penile cancer are particularly poor hygiene and age. It is much less common in men who have had all or part of their foreskin removed (been circumcised) soon after birth. This is because men who have not been circumcised may find it more difficult to pull back the foreskin enough to clean thoroughly underneath. Smegma, a cheese-like, foul-smelling substance found under the foreskin of the penis may increase the risk of penis cancer
The most important risk factor for penile cancer is infection with this virus. HPV is most commonly passed from person to person during sexual activity. Smoking may contribute to the development of penile cancer, especially in men who are also infected with HPV. Men who have been treated with the drug psoralen combined with ultraviolet (UV) light have a higher risk of developing penile cancer. Infection with human immune deficiency virus (HIV), the virus that causes acquired immune deficiency syndrome (AIDS), is also a risk factor. Incidence of penile cancer of people who are bothered by tight foreskin of the penis is much higher than other men.
CLINICAL MANIFESTATIONS
Men with penile cancer may experience the following symptoms or signs. Sometimes, men with penile cancer do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer
- Genital lesions of the penis
- Painless sore on penis
- Penis pain
- Changes in the color of the penis
- Skin thickening on the penis
- Foul odor discharge beneath the foreskin
- Blood coming from tip of penis or under foreskin
- Unexplained pain in the shaft or tip of the penis
- Irregular or growing bluish-brown flat lesions
- Reddish, velvety rash beneath the foreskin
- Small, crusty bumps beneath the foreskin
- Swollen groin lymph nodes
DIAGNOSTIC EVALUATIONS
Doctors use many tests to diagnose cancer and find out if it has metastasized (spread).
- Physical examination
- Biopsy
- Fine needle aspiration/biopsy
- Sentinel lymph node biopsy
- Inguinal (groin) lymph node dissection
- X-ray
- Computed tomography (CT or CAT) scan
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET) scan
STAGES OF PENILE CANCER
After penile cancer has been diagnosed, tests are done to find out if cancer cells have spread within the penis or to other parts of the body.
Stage 0 (carcinoma in situ): In stage 0, abnormal cells are found on the surface of the skin of the penis. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ
Stage I: In stage I, cancer has formed and spread to connective tissue just under the skin of the penis.
Stage II: In stage II, cancer has spread to: connective tissue just under the skin of the penis and to one lymph node in the groin; or erectile tissue (spongy tissue that fills with blood to make an erection) and may have spread to one lymph node in the groin.
Stage III: In stage III, cancer has spread to: connective tissue or erectile tissue of the penis and to more than one lymph node on one or both sides of the groin; or the urethra or prostrate, and may have spread to one or more lymph nodes on one or both sides of the groin
Stage IV: In stage IV, cancer has spread: to tissues near the penis and may have spread to lymph nodes in the groin or pelvis; or anywhere in or near the penis and to one or more lymph nodes deep in the pelvis or groin; or to distant parts of the body.
MANAGEMENT
Different types of treatments are available for patients with penile cancer. Treatment depends on the size and location of the tumor and how much it has spread. In general, cancer treatment includes: chemotherapy, radiation therapy and surgery.
1. Surgery: Surgery is the most common treatment for all stages of penile cancer. The goal of surgery is to remove the cancer, along with some surrounding tissue in order to make sure that the entire cancer is removed. A doctor may remove the cancer using one of the following operations:
- Mohs microsurgery: A procedure in which the tumor is cut from the skin in thin layers. During the surgery, the edges of the tumor and each layer of tumor removed are viewed through the microscope to check for cancer cells. Layers continue to be removed until no more cancer cells are seen. This type of surgery removes as little normal tissue as possible and is often used to remove cancer on the skin. It is also called Mohs surgery
- Laser surgery: A surgical procedure that uses a laser beam (a narrow beam of intense light) as a knife to make bloodless cuts in tissue or to remove a surface lesion such as a tumor.
- Cryosurgery: cryosurgery (also called cryotherapy or cryoablation) uses liquid nitrogen to freeze and kill cells. The skin will later blister and slough off. This procedure will sometimes leave a pale scar. More than one freezing may be needed.
- Circumcision: circumcision involves an operation to remove the foreskin from the penis; along with some surrounding skin. This method is generally used if the cancer is limited to the foreskin
- Wide local excision: surgery to remove only the cancer and some normal tissue around it. If the cancer has spread over a wider area, patient will need to have an operation known as a wide local excision. This means removing the cancer with a border of healthy tissue around it. This border of healthy tissue is important as it reduces the risk of the cancer coming back in the future.
- Electrodessication and curettage: electrodessication and curettage removes the cancer by scraping the tumor with a curette (thin, long instrument with a scraping edge) and applying an electric current to the area to kill cancer cells
- Amputation of the penis: surgery to remove part or the entire penis. If part of the penis is removed, it is a partial penectomy. If the entire penis is removed, it is a total penectomy.
2. Radiotherapy: Radiotherapy treats cancer using high-energy rays to destroy cancer cells, while doing as little harm as possible to healthy cells. It used to be a common treatment for small cancers of the head of the penis (glans), but nowadays it is used less often because of improvements in surgery. However, radiotherapy may be used to treat affected lymph nodes in the groin to help reduce the risk of the cancer spreading. It may also be given to treat symptoms, such as pain, if the cancer has spread to other parts of the body, like the bones.
3. Chemotherapy: chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Chemotherapy cream may sometimes be used to treat very small, early cancers that are confined to the foreskin and end of the penis (glans). It may be given along with surgery or radiotherapy (or both). Chemotherapy may be used along with surgery or radiotherapy (or both). Bleomycin, cisplatin, or methotrexate alone or together is usually used for treating penile cancer
4. Biologic therapy: biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy. Topic biologic therapy may be used to treat stage 0 penile cancer
5. Photodynamic therapy (PDT): this is a newer type of treatment which is used for different conditions. At the moment it’s still being tested to see how effective it is for treating penile cancer. It uses laser, or other light sources combined with a light sensitive drug (photosensitizing agent), to destroy abnormal cells. A photosensitizing cream is applied to the affected area usually 3-6 hours before the light treatment. The light treatment is then given for a specific period of time which varies depending on the light source.
PENILE CANCER – Types, Causes and Risk Factors, Clinical Manifestations, Diagnostic Evaluations, Stages and Management