Penile cancer is a very rare form of cancer that occurs mostly in uncircumcised men (men with the foreskin, a piece of skin covering the head of their penis, intact). The penis is the external male genital organ, and consists of three chambers of spongy tissue that contain multiple blood vessels, nerves, and smooth muscle. The corpora cavernosa make up two of the chambers, and are located on both sides of the upper part of the penis. The corpus spongiosum is located below the corpora cavernosa and surrounds the urethra, the tube through which urine and semen exit the body at an opening called the meatus. At the tip of the penis, the corpora cavernosa expands to form the helmet, or glans.
There are several types of penile cancers:
Epidermoid carcinoma. Ninety-five percent (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. There is non-melanoma skin cancer that can develop anywhere on the penis, but 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 (one of the layers of the tissues that cover the penis) are round cells known as basal cells. These can occasionally become cancerous. 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. While the penis is not usually exposed directly to sunlight, this sun-related cancer does occasionally occur on the surface of the penis.
Sarcoma. About 1% of penile cancers are sarcomas, cancers that develop in the tissues that support and connect the body, such as blood vessels, smooth muscle, and fat.
Risk Factors and Prevention
A risk factor is anything that increases a person's chance of developing a disease, including cancer. For cancer in general, there are risk factors that can be controlled, such as smoking, and risk factors that cannot be controlled, such as family history. Although risk factors can influence disease, they do not cause cancer. Some people with several risk factors never develop the disease, while others with no known risk factors do. Knowing your risk factors and communicating with your doctor can help guide you in making wise lifestyle and health-care choices.
The following factors can raise a person's risk of developing penile cancer:
Human papillomavirus (HPV) infection. The most important risk factor is infection with HPV. HPV is passed from one person to another during sexual intercourse. High-risk sexual behavior that can lead to HPV infection includes intercourse at an early age, multiple sexual partners, sex with a person who has had many partners, and unprotected sex.
Smoking. Smoking may contribute to the development of penile cancer, especially in men who are also infected with HPV.
Age. Most cases of penile cancer occur in men over age 50, but occur in men younger than 40 about 20% of the time.
Smegma. Smegma is a thick substance that can accumulate under the foreskin and is caused by dead skin cells, bacteria, and oily secretions from the skin. Smegma may contain small amounts of cancer-causing substances. Uncircumcised men should retract the foreskin and thoroughly wash the penis on a regular basis, in order to make sure that smegma does not cause irritation of the penis.
Phimosis. Phimosis occurs when the foreskin becomes constricted and is difficult to retract, therefore causing a buildup of smegma. Men with phimosis are less likely to be able to thoroughly clean the penis.
HIV/AIDS infection. Infection with human immunodeficiency virus (HIV), the virus that causes acquired immune deficiency syndrome (AIDS), is also a risk factor. When a person is HIV positive, their immune system is less able to fight off early stage cancers.
Psoriasis treatment. Men who have been treated with the drug psoralen combined with ultraviolet (UV) light have a higher risk of developing penile cancer.
Circumcision. Circumcision is a procedure to remove the foreskin of the penis and may provide some protection from penile cancer due to improved hygiene. Squamous cell carcinoma of the penis almost never occurs in men who are circumcised. It is important to note that circumcision alone cannot prevent penile cancer.
Personal hygiene. Men who carefully and completely clean under the foreskin on a regular basis can reduce their risk of developing penile cancer.
While it is not possible to completely prevent penile cancer, a man can reduce his risk by avoiding the known risk factors, especially smoking, avoiding sexual practices that could lead to HPV or HIV/AIDS infection, and practicing good hygiene.
Men with penile cancer often experience the symptoms below. Sometimes, men with penile cancer do not show any of these symptoms. Or, these symptoms may be similar to those of other medical conditions. If you are concerned about a symptom on this list, please talk to your doctor.
- A growth or ulcer on the penis, especially on the glans or foreskin, but also on the shaft
- Changes in color on the penis
- Skin thickening on the penis
- Persistent discharge with foul odor beneath the foreskin
- Blood coming from the tip of the penis or under the foreskin
- Unexplained pain in the shaft or tip of the penis
- Irregular or growing bluish-brown flat lesions or marks beneath the foreskin or on the body of the penis
- Reddish, velvety rash beneath the foreskin
- Small, crusty bumps beneath the foreskin
- Swollen groin lymph nodes
- Irregular swelling at the end of the penis
Doctors use many tests to diagnose cancer and determine if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
- Age and medical condition
- The type of cancer
- Severity of symptoms
- Previous test results
The following tests may be used to diagnose penile cancer:
Biopsy. A biopsy removes a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a diagnosis for certain.
Fine needle aspiration. A local anesthetic may be injected into the skin near the nodule prior to the biopsy. The doctor will insert a thin needle into the nodule and extract (take out) cells and some fluid. The procedure may be repeated two or three times to obtain samples from different areas of the nodule. The report, done by a pathologist, can be positive (for malignant cells), negative, or undetermined.
Sentinel lymph node biopsy. It is important to know if cancer cells have spread to other areas. In this technique, the doctor removes one or a few sentinel lymph nodes, the first node(s) into which the lymph system drains, to check for cancer cells. In the case of penile cancer, the sentinel lymph nodes are located just under the skin in the groin. If cancer cells are detected, it means that the disease may have spread to other lymph nodes in the region or beyond through the blood and lymph vessels.
X-ray. A picture is taken of areas inside the body to help the doctor identify the presence of a tumor. An x-ray is usually used to examine the lungs for evidence of metastases. This is known as a chest x-ray.
Computerized tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows abnormalities or tumors.
Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body.
Through ongoing research, the medications used to treat cancer are constantly being evaluated in different combinations and to treat different cancers. Talking with your doctor is often the best way to learn about the medications you've been prescribed, their purpose, and their potential side effects or interactions.
The treatment of penile cancer depends on the size and location of the tumor, whether the cancer has spread, and the person's overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan.
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. The various types of surgery are performed under local or general anesthesia, depending on the patient's preference and the physician's recommendations.
Penectomy. The surgical removal of all or part of the penis is the most common and effective procedure to treat penile cancer that has invaded the inside of the penis.
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 white scar. More than one freezing may be needed.
Mohs surgery. This technique involves surgically removing the visible cancer, in addition to small fragments of the edge where the tumor existed under microscopic control. Each small fragment is examined under a microscope until all cancer is removed. This is typically used for larger tumors, those in hard to reach places, and for cancers that have come back in the same place.
Circumcision. Circumcision involves an operation to remove of the foreskin from the penis, along with some neighboring skin. This method is generally used if the cancer is limited to the foreskin.
Curettage and electrodesiccation. In this procedure, the cancer is removed with a curette, a sharp, spoon-shaped instrument. The area can then be treated with electrodesiccation, which uses electric current to control bleeding and kill any remaining cancer cells. Many people have a flat, white scar from this procedure.
A narrow beam of high-intensity light can remove or destroy cancer confined to the outermost layer of the skin.
Radiation therapy uses high-energy x-rays or other particles to kill cancer cells, and several treatments may be needed. The treatment may produce a rash, make the skin dry or red, and/or change the color of the skin.
Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy uses drugs to target cancer cells throughout the body and may help control advanced penile cancer. The side effects of chemotherapy depend on the individual and the dose used, but can include fatigue, risk of infection, nausea and vomiting, and hair loss. These side effects usually go away once treatment is finished. Topical chemotherapy is when the drugs are placed directly onto the skin in the form of a topical cream. Today, advanced penile cancer is often treated with a combination of chemotherapy and radiation therapy. Chemotherapy drugs that have some beneficial effects in reducing penile cancer include bleomycin (Blenoxane), methotrexate (Immunex, Folex PFS, Rheumatrex), cisplatin (Platinol), and paclitaxel (Taxol) or docetaxel (Taxotere). It should be noted that not all of these drugs are readily available for penile cancer, and may only be available as part of a clinical trial.
Side Effects of Cancer and Cancer Treatment
Cancer and cancer treatment can cause a variety of side effects; some are easily controlled and others require specialized care. Below are some of the side effects that are more common to penile cancer and its treatments.
Fatigue (tiredness). Fatigue is extreme exhaustion or tiredness, and is the most common problem that people with cancer experience. More than one-half of patients experience fatigue during chemotherapy or radiation therapy, and up to 70% of patients with advanced cancer experience fatigue. Patients who feel fatigue often say that even a small effort, such as walking across a room, can seem like too much. Fatigue can seriously impact family and other daily activities, can make patients avoid or skip cancer treatments, and may even impact the will to live.
Hair loss (alopecia). A potential side effect of radiation therapy and chemotherapy is hair loss. Radiation therapy and chemotherapy cause hair loss by damaging the hair follicles responsible for hair growth. Hair loss may occur throughout the body, including the head, face, arms, legs, underarms, and pubic area. The hair may fall out entirely, gradually, or in sections. In some cases, the hair will simply thin-sometimes unnoticeably-and may become duller and dryer. Losing one's hair can be a psychologically and emotionally challenging experience and can affect a patient's self-image and quality of life. However, the hair loss is usually temporary, and the hair often grows back.
Infection. An infection occurs when harmful bacteria, viruses, or fungi (such as yeast) invade the body and the immune system is not able to destroy them quickly enough. Patients with cancer are more likely to develop infections because both cancer and cancer treatments (particularly chemotherapy and radiation therapy to the bones or extensive areas of the body) can weaken the immune system. Symptoms of infection include fever (temperature of 100.5°F or higher); chills or sweating; sore throat or sores in the mouth; abdominal pain; pain or burning when urinating or frequent urination; diarrhea or sores around the anus; cough or breathlessness; redness, swelling, or pain, particularly around a cut or wound; and unusual vaginal discharge or itching.
Mouth sores (mucositis). Mucositis is an inflammation of the inside of the mouth and throat, leading to painful ulcers and mouth sores. It occurs in up to 40% of patients receiving chemotherapy treatments. Mucositis can be caused by a chemotherapeutic drug directly, the reduced immunity brought on by chemotherapy, or radiation treatment to the head and neck area.
Nausea and vomiting. Vomiting, also called emesis or throwing up, is the act of expelling the contents of the stomach through the mouth. It is a natural way for the body to rid itself of harmful substances. Nausea is the urge to vomit. Nausea and vomiting are common in patients receiving chemotherapy for cancer and in some patients receiving radiation therapy. Many patients with cancer say they fear nausea and vomiting more than any other side effects of treatment. When it is minor and treated quickly, nausea and vomiting can be quite uncomfortable but cause no serious problems. Persistent vomiting can cause dehydration, electrolyte imbalance, weight loss, depression, and avoidance of chemotherapy.
Nervous system disturbances. Nervous system disturbances can be caused by many different factors, including cancer, cancer treatments, medications, or other disorders. Symptoms that result from a disruption or damage to the nerves caused by cancer treatment (such as surgery, radiation treatment, or chemotherapy) can appear soon after treatment or many years later. See Managing Side Effects: Nervous System Disturbances for the most common symptoms.
Sexual dysfunction. Sexual dysfunction is common in all people, affecting up to 43% of women and 31% of men. It may be even more common in patients with cancer, as a result of treatments, the tumor, or stress. Many people, with or without cancer, find it intimidating to discuss sexual problems with their doctors. Sexual problems are most commonly caused by body changes from cancer surgery, chemotherapy or radiation therapy, hormone changes, fatigue (tiredness), pain, nausea and/or vomiting, medications that reduce libido (desire for sex), fear of recurrence, stress, depression, and anxiety. Symptoms of sexual dysfunction generally fall into four categories: desire disorders, arousal disorders, orgasmic disorders, and pain disorders. Specific problems may occur in the patient who has had surgery to remove all or part of the penis, and this requires careful counseling and assistance by experts in the field.
Skin problems. The skin is an organ system that contains many nerves. Because of this, skin problems can be very painful. Because the skin is on the outside of the body and visible to others, many patients find skin problems especially difficult to cope with. Because the skin protects the inside of the body from infection, skin problems can often lead to other serious problems. As with other side effects, prevention or early treatment is best. In other cases, treatment and wound care can often improve pain and quality of life. Skin problems can have many different causes, including chemotherapeutic drugs leaking out of the intravenous (IV) tube, which can cause pain or burning; peeling or burned skin caused by radiation therapy; pressure ulcers (bed sores) caused by constant pressure on one area of the body; and pruritus (itching) in patients with cancer, most often caused by leukemia, lymphoma, myeloma, or other cancers.
After the treatment of penile cancer, a patient will be followed regularly by his oncologist or surgeon. The patient will typically have regular physical examinations, with specific examination of the penis itself and the lymph nodes in the groin. Depending on the anticipated level of risk of relapse, a patient may need to undergo occasional chest x-rays or CT scans, as well as some blood tests.
Once the patient has been effectively treated for penile cancer, it is wise to practice safe sex and to ensure that careful hygiene is practiced. There are no drugs or remedies proven to reduce the chances of relapse or second primary cancers in this setting.