What is Penile Cancer ?

About the penis
The penis is the external male genital organ, and contains several types of tissue, including skin, nerves, smooth muscle, and blood vessels. Inside the penis is the urethra, the tube through which urine and semen exit the body. The head of the penis is called the glans. At birth the glans is covered by a loose piece of skin called the foreskin or prepuce.

Inside the penis are three chambers that contain a soft, spongy network of blood vessels. Two of these cylinder-shaped chambers, known as the corpora cavernosa, lie on either side of the upper part of the penis. The third lies below them and is known as the corpus spongiosum. This chamber widens at its end to form the glans. The urethra, a tube that carries urine from the bladder through the penis, runs between the corpus spongiosum. The opening at the end of the urethra is called the meatus. Semen consists of prostatic fluid produced by the seminal vesicles and prostate gland and transports sperm cells from the testicles. This fluid is produced and stored in the seminal vesicles (two small sacs near the bladder and prostate). During ejaculation, semen from the seminal vesicles passes through the ejaculatory ducts into the urethra, and leaves the body through the meatus at the tip of the penis.

When a man gets an erection, nerves signal the body to send blood into the vessels inside the corpora cavernosa and corpus spongiosum. As the blood fills the chamber, the spongy tissue expands, causing the penis to elongate and stiffen. After ejaculation, the blood flows out of the penis, causing it to become soft again.

Cancers of the penis
Each of the tissues in the penis contains several types of cells. Different types of penile cancer (cancer of the penis) can develop in each kind of cell. The differences are important, because they determine the seriousness of the cancer and the type of treatment needed. About 95% of penile cancers develop from flat, scale-like skin cells called squamous cells.

Like most other forms of nonmelanoma skin cancer, these tumors tend to grow slowly. When detected in the early stages, these tumors can usually be cured. Squamous cell penile cancers can develop anywhere on the organ, but most develop on the foreskin (in men who have not been circumcised) or on the glans.

Verrucous carcinoma is an uncommon form of squamous cell cancer that can occur on the male or female genitals, skin, mouth, larynx, and anus. Verrucous carcinoma of the genitals is sometimes also called a Bushke-Lowenstein tumor. Due to its appearance, it is often difficult to distinguish from a benign genital wart (see the section "Benign and Precancerous Conditions" for more information). These low-grade cancers can spread deeply into surrounding tissue but very rarely do they metastasize.

A very rare type of penile cancer called adenocarcinoma can develop from sweat glands in the skin of the penis. Paget's disease of the penis is a condition in which adenocarcinoma cells are found in the penile skin. The cancer cells at first spread within the skin, but may eventually invade underneath the skin and spread to lymph nodes. Paget's disease can affect skin anywhere in the body but most often affects skin of the perianal area, vulva, and the breasts. This condition should not be confused with Paget's disease of the bone, an entirely different disease also named after Dr. James Paget.

The earliest stage of squamous cell cancer of the penis (or any other organ) is called squamous cell carcinoma in situ (abbreviated as CIS). Penile CIS is contained entirely within the skin of the penis and has not yet spread to deeper tissues of the penis. Depending on the exact location of a CIS of the penis, doctors may give additional names to the disease. CIS of the glans is sometimes called erythroplasia of Queyrat. The same condition, when found on the shaft of the penis (or skin of other parts of the body), is called Bowen's disease.

About 2% of penile cancers develop from pigment-producing skin cells called melanocytes. Cancers of these cells are called melanoma. These cancers are more dangerous because they grow and spread more rapidly. Melanomas usually develop from sun-exposed areas of skin. Although sun exposure is an important risk factor for melanoma, a few of these cancers can develop on the penis, or other areas not likely to become sunburned.

Basal cell cancers are most common cancers of sun exposed areas of skin, such as the face, neck and arms. Basal cell cancers represent less than 2% of penile cancers. They are slowly growing tumors that very rarely spread to other parts of the body.

The remaining 1% of penile cancer consists mostly of sarcomas, cancers that develop from the blood vessels, smooth muscle, and other connective tissue cells of the penis.

Benign and precancerous conditions
Sometimes abnormal growths develop on the penis which are benign (not cancerous). Some of these benign growths may eventually evolve into invasive cancer if they are not treated. These premalignant conditions can resemble warts or irritated patches of skin. Like penile cancer, they usually develop on the glans or on the foreskin, but they can also occur along the shaft of the penis.

Condylomas are wart-like growths that resemble tiny cauliflowers. Some are so small that they are apparent only when the skin is viewed under a magnifying lens. Others may reach an inch or more in diameter.

Squamous cell cancer of the penis usually forms slowly over many years, and is usually preceded by precancerous changes that may last for several years. The medical terms for this precancerous condition are penile intraepithelial neoplasia, or dysplasia. "Intraepithelial" means that the precancerous cells are confined to the epithelium (surface layer of the penile skin).

Prevention
The large variations in penile cancer rates throughout the world strongly suggest that penile cancer is a preventable disease. The best way to reduce the risk of penile cancer is to avoid known risk factors whenever possible.

In the past, circumcision has been suggested as a strategy for preventing penile cancer. This suggestion is based on studies that reported much lower penile cancer rates among circumcised men than among uncircumcised men. However, most researchers now believe those studies were flawed, because they failed to consider other factors that are now known to affect penile cancer risk. For example, some recent studies suggest that circumcised men tend to have certain other lifestyle factors associated with lower penile cancer risk -- they are less likely to have multiple sexual partners, less likely to smoke, and more likely to have good personal hygiene habits. Most public health researchers believe that the penile cancer risk among uncircumcised men without known risk factors living in the United States is extremely low. The current consensus of most experts is that circumcision should not be recommended as a strategy for penile cancer prevention.

On the other hand, it is reasonable to suspect that avoiding sexual practices likely to result in human papillomavirus (HPV) infection might lower penile cancer risk. In addition, these practices are likely to have an even more significant impact on cervical cancer risk. Until recently, it was thought that the use of condoms ("rubbers") could prevent infection with HPV. But recent research shows that condoms cannot protect against infection with HPV. This is because HPV can be passed from person to person by skin-to-skin contact with any HPV-infected area of the body, such as skin of the genital or anal area not covered by the condom. It is still important, though, to use condoms to protect against AIDS and other sexually transmitted diseases that are passed on through some body fluids. The absence of visible warts cannot be used to decide whether caution is warranted, since HPV can be passed on to another person even when there are no visible warts or other symptoms. HPV can be present for years with no symptoms, so it can be difficult or impossible to know whether a person with whom you might have sex might be infected with HPV.

It is also known that the longer a person remains infected with any type of HPV that can cause cancer, the greater the risk that infection will lead to cancer. For these reasons, postponing the beginning of sexual activity in life and limiting the number of sexual partners are two ways to reduce the chances of developing penile cancer.
Smoking is another factor associated with increased penile cancer risk. And, it is even more strongly associated with several very common and frequently fatal cancers, as well as noncancerous conditions such as heart disease and stroke. Quitting smoking or never starting in the first place is an excellent recommendation for preventing a wide variety of diseases, including penile cancer.

Because poor hygiene habits are associated with increased penile cancer risk, and some studies suggest that smegma (the material that accumulates underneath the foreskin) may contain cancer-causing substances, many public health experts recommend that uncircumcised men practice good genital hygiene by retracting the foreskin and cleaning the entire penis. If the foreskin is constricted and difficult to retract, a physician may be able to place a small cut (incision) in the skin to make retraction easier.

Since some men with penile cancer have no known risk factors, it is not possible to completely prevent this disease.


Diagnostic
Because penile lesions affect the skin tissue on the surface of the organ, cancers and other abnormalities are usually detected during a visual examination of the penis. Swelling at the end of the penis, especially when the foreskin is constricted, is another common sign that penile cancer may be present.

To determine the exact nature of the abnormality, a biopsy is needed. In this procedure, a small piece of the skin tissue is cut out and sent to a laboratory. There, a pathologist (a doctor specializing in laboratory diagnosis of diseases) looks at the tissue under a microscope to see whether cancer cells are present.

The type of biopsy depends on the nature of the abnormality. If the doctor detects nodules (swollen lumps) or plaques (raised, flat areas) that are 1 cm (about 3/8 inch) or less in size, an excisional biopsy will be performed in which the entire lesion is removed. An incisional biopsy, in which only a portion of the affected tissue is removed, will be performed on lesions that are larger or ulcerated or that appear to grow deeply into the tissue. These biopsies use local anethesia (numbing medication) and are done in a doctor's office, clinic, or outpatient (1 day) surgical center. The tissue is then sent to a laboratory, where a pathologist examines the tissue under a microscope. The results of this test are available within usually 3-4 days.

If cancer is found in the biopsy sample, you will probably be asked to undergo imaging tests such as ultrasound, computed tomography (CT) scanning, or magnetic resonance imaging (MRI), to see how far the cancer has spread.

Ultrasound, also known as ultrasonography, uses sound waves to penetrate deep into tissues. Sound waves are sent out from the ultrasound probe, which is placed on the skin of the penis. The sound waves that bounce off the normal tissues and the cancer are detected by the probe and analyzed by a computer to determine how deeply the tumor has invaded into the penis.

The CT scan uses a rotating x-ray beam to create a series of pictures of your body from many angles. A computer processes the information provided by the scan, producing a detailed image of a selected part of your body. To highlight details on the CT scan, a harmless dye may be injected into a vein. The CT scan may reveal the presence of enlarged lymph nodes, which could be a sign of a spreading cancer, or they could mean that your body is fighting an infection.

MRI uses magnetic fields and radio waves instead of x-rays to create images of selected areas of your body. These images can also show enlarged lymph nodes that might be cancer, or a reaction to infection.
Although imaging tests can identify large lymph nodes that might contain cancer, they cannot prove whether their large size is a response to an infection or due to the spread of cancer. When large groin nodes are surgically removed from men with penile cancer, only about half are actually found to contain cancer. The most accurate method to check for cancer in these groin lymph nodes is to remove them by an operation called an inguinal lymph node dissection (surgical removal of lymph nodes in the groin).

Fine needle aspiration (FNA) is a type of biopsy that can be done in a doctor's office or clinic. Local anesthesia may be injected into the skin over the mass. Anesthesia may not be needed in some cases. The doctor places a thin needle directly into the mass for about 10 seconds and withdraws cells and a few drops of fluid. These cells can then be viewed under a microscope to determine if cancer is present. If the mass is deep inside the body and cannot be felt by the doctor, imaging methods such as ultrasound or a CT scan can be used to guide the needle into the enlarged lymph node. FNA is not used in every case, but is one alternative to lymph node dissection for some patients.

Sentinel lymph node biopsy is an alternative to total lymph node dissection that, for several years, has been used successfully for some patients with breast cancer or malignant melanoma. Some doctors recommend its use for some men with penile cancer. In this procedure, a radioactive tracer and/or a blue dye is injected into the region of the tumor. The dye or radioactive material is carried by the lymphatic vessels to a "sentinel node," the first lymph node receiving lymph from the tumor and the one most likely to contain a metastasis if the cancer has spread. The sentinel node is detected by the surgeon in the operating room by either visualization (blue dye), or with a Geiger counter (radioactive tracer).

This node is removed. If the sentinel node contains cancer, more lymph nodes are removed. If the sentinel node is free of cancer, additional lymph node surgery may be avoided. Using this approach, fewer patients will need to have many lymph nodes removed. Removing lymph nodes, carries a risk of side effects such as lymphedema (fluid accumulation in tissues) and problems with wound healing.

If your doctor is considering this procedure, it might be useful to determine how many sentinel node biopsies he/she has done, and whether this approach will be part of a research study. It is also important to note that sentinel lymph node biopsy is not accepted by all physicians as an alternative to a more traditional total lymph node removal. Discuss it with your physician.

Treatment
In recent years, much progress has been made in treating penile cancer. New medications or ways to use medications have been developed. Surgical methods involving microscopic techniques and lasers have been refined (which are less disfiguring than surgical removal of the penis), and more is known about the best way to use radiation.

After the cancer is found and staged, your cancer care team will discuss treatment options (choices) with you. It is important to take time and think about all of the choices. In choosing a treatment plan, factors to consider include the type and stages of the cancer, your overall physical health, and your personal preferences about treatments and their side effects.

It is often a good idea to seek a second opinion. A second opinion can provide more information and help you feel more confident about the treatment plan that is chosen. Some insurance companies require a second opinion before they will agree to pay for certain treatments.

The three main methods of treatment for penile cancer are surgery, radiation therapy, and chemotherapy.
The best approach for some patients may involve two or more of these strategies. Your recovery is the goal of your cancer care team. If a cure is not possible, the goal may be to remove or destroy as much of the cancer as possible and to prevent the tumor from growing, spreading, or returning for as long as possible. Sometimes treatment is aimed at relieving symptoms, such as pain or bleeding, even if a cure will not result.


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