Penile Cancer
Penile cancer starts in or on the Glans or the corona.
Anatomy of penis
The penis is the external male sex organ. It's also part of the urinary system. It's made up of many types of body tissues, including skin, nerves, smooth muscle, and blood vessels.
The main part of the penis is known as the shaft, and the head of the penis is called the glans. At birth, the glans is covered by a piece of skin called the foreskin, or prepuce. The foreskin is often removed in infant boys in an operation called a circumcision.
Inside the penis are 3 chambers that contain a soft, spongy network of blood vessels. Two of these cylinder-shaped chambers, known as the corpora cavernosa, are on either side of the upper part of the penis. The third chamber is below them and is known as the corpus spongiosum. This chamber widens at its end to form the glans. The corpus spongiosum surrounds the urethra, a thin tube that starts at the bladder and runs through the penis. Urine and semen travel through the urethra and leave the body through an opening in the glans of the penis, called the meatus.
To get an erection, nerves signal a man's body to store blood in the vessels inside the corpora cavernosa. As blood fills the chambers, the spongy tissue expands and the penis stiffens and gets longer. During ejaculation, semen (which contains sperm cells and fluids) flows through the urethra and out of the body through the meatus. After ejaculation, the blood flows back into the body, and the penis becomes soft again.
Benign conditions of the penis
These lesions often look like warts or irritated patches of skin. Like penile cancer, they're most often found on the glans or on the foreskin, but they can also occur along the shaft of the penis.
Condylomas (genital warts)
These growths tend to look like tiny cauliflowers. Others may be as large as an inch or more across. Condylomas are caused by infection with certain types of human papillomavirus (HPV).
Bowenoid papulosis
This condition is also linked to infection with HPV and tends to occur in younger, sexually active men. It's seen as small, red or brown spots or patches on the shaft of the penis. These may look like genital warts, but when looked at under a microscope, dysplastic (abnormal) cells are seen in the surface layer of the penile skin.
Bowenoid papulosis can also be mistaken for an early-stage cancer called carcinoma in situ (CIS), also known as Bowen disease. Usually bowenoid papulosis doesn’t cause any problems, and it can even go away on its own after a few months. But if it doesn’t go away and isn't treated, in rare cases it can progress to Bowen disease.
Cancers of the penis
Almost all penile cancers start in skin cells of the penis.
Squamous cell carcinoma
About 95% of penile cancers start in flat skin cells called squamous cells. Squamous cell carcinoma (also known as squamous cell cancer) can start anywhere on the penis. Most of these cancers start on the foreskin (in men who have not been circumcised) or on the glans. These tumors tend to grow slowly. If they're found at an early stage, they can usually be cured.
Verrucous carcinoma: A verrucous carcinoma growing on the penis is also known as Buschke-Lowenstein tumor.This is an uncommon form of squamous cell cancer that can start in the skin in many areas. This cancer looks a lot like a large genital wart. Verrucous carcinomas tend to grow slowly but can sometimes get very large. They can grow deep into nearby tissue, but they rarely spread to other parts of the body.
Carcinoma in situ (CIS): This is the earliest stage of squamous cell cancer of the penis. In this stage, the cancer cells are found only in the top layers of skin. They have not yet grown into the deeper tissues. Depending on where the CIS is on the penis, doctors may use other names for the disease.
- CIS of the glans is sometimes called erythroplasia of Queyrat.
- CIS on the shaft of the penis (or other parts of the genitals) is called Bowen disease.
Melanoma
Melanoma is a type of skin cancer that starts in melanocytes, the cells that make the brownish color in the skin that helps protect it from the sun. These cancers tend to grow and spread quickly. They're more dangerous than the more common basal and squamous cell types of skin cancer. Melanomas are most often found in sun-exposed skin, but rarely they occur in other places like the penis.
Basal cell carcinoma
Basal cell carcinoma (also known as basal cell cancer) is another type of skin cancer that can develop on the penis. It makes up only a small portion of penile cancers. This type of cancer is slow-growing and rarely spreads to other parts of the body.
Adenocarcinoma (Paget disease of the penis)
This very rare type of penile cancer can develop from sweat glands in the skin of the penis. It can be very hard to tell apart from carcinoma in situ (CIS) of the penis.
Sarcoma
A small number of penile cancers are sarcomas. These cancers develop from blood vessels, smooth muscle, or other connective tissue cells of the penis.
Risk Factors for Penile Cancer
A risk factor is anything that affects your chance of getting a disease like cancer.
-
Human papillomavirus (HPV) infection
Human papillomavirus (HPV) is a group of more than 150 related viruses. They are called papillomaviruses because some of them cause growths called papillomas (warts). Different HPV types cause different types of warts in various parts of the body. Certain HPV types can infect the genital organs and the anal area, causing raised, bumpy warts called condyloma acuminata (or just condylomas). Other HPV types (16 and 18) have been linked with cancers. In fact, HPV is found in about half of all penile cancers.
HPV is passed from one person to another during skin-to-skin contact with an infected area of the body. HPV can be spread during sexual activity – including vaginal, anal, and oral – but sex doesn’t have to occur for the infection to spread. All that's needed is skin-to-skin contact with an area of the body infected with HPV. Infection with HPV can also spread from one part of the body to another. For example, infection may start in the penis and then spread to the anus. HPV infection is common. In most men, the body clears the infection on its own. But in some, the infection doesn't go away and becomes chronic. Over time, chronic infection, can cause penile cancer. Men who are not circumcised may be more likely to get and stay infected with HPV.
-
Not being circumcised
Circumcision removes all (or part) of the foreskin. This procedure is most often done in infants, but it can be done later in life, too. Men who were circumcised as children may have a much lower chance of getting penile cancer than those who were not. In fact, some experts say that circumcision as an infant prevents this cancer. The same protective effect is not seen if circumcision is done as an adult. The reason for the lower risk in circumcised men is not entirely clear, but it may be related to other known risk factors. For example, men who are circumcised can’t develop the condition called phimosis, and they don’t accumulate smegma. Men with smegma or phimosis have an increased risk of penile cancer. The later a man is circumcised, it's more likely that one of these conditions may have occured.
-
Phimosis and smegma
Uncircumcised men with certain conditions are at higher risk for penile cancer.
Phimosis - In men who are not circumcised, the foreskin can sometimes become tight and difficult to retract. This is known as phimosis. Penile cancer is more common in men with phimosis. The reason for this is not clear, but it might be related to the build-up of smegma or from inflammation that results from phimosis.
Smegma - Sometimes secretions can build up underneath an intact foreskin. If the area under the foreskin isn’t cleaned well, these secretions build up enough to become a thick, sometimes smelly substance called smegma. Smegma is more common in men with phimosis, but can occur in anyone with a foreskin if the foreskin isn't retracted regularly to clean the head of the penis. Smegma itself probably doesn’t cause penile cancer, but it can irritate and inflame the penis, which can increase the risk of cancer.
-
Smoking and other tobacco use
Men who smoke and/or use other forms of tobacco are more likely to develop penile cancer. Tobacco users who have HPV infections have an even higher risk. Tobacco use exposes your body to many cancer-causing chemicals. These harmful substances are inhaled into the lungs, where they are absorbed into the blood, or they're absorbed through mouth tissues into the blood. They can travel in the bloodstream throughout the body to cause cancer in many different areas.
-
UV light treatment of psoriasis
Men who have a skin disease psoriasis and are treated with drugs called psoralens and then an ultraviolet A (UVA) light source (PUVA therapy), have a higher rate of penile cancer. To help lower this risk, genitals are covered during PUVA treatment.
-
Age
The risk of penile cancer goes up with age.
-
AIDS
Men with AIDS have a higher risk of penile cancer. This higher risk seems to be linked to their weakened immune system. Other factors also contribute for example. men with HIV are more likely to smoke and be infected with HPV
Staging of penile cancer
|
AJCC stage |
Stage grouping |
Stage description* |
|
0 |
Tis or Ta |
Also called carcinoma in situ or CIS. The tumor is only in the top layer of the skin and has not grown any deeper (Tis or Ta). The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0). |
|
I |
T1a |
The tumor has grown into tissue just below the top layer of skin. It hasn't grown into nearby blood vessels, lymph vessels, or nerves, and it's not high grade (grade 3) (T1a). The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0). |
|
IIA |
T1b |
The tumor has grown into tissue just below the top layer of skin. It has grown into nearby blood vessels, lymph vessels, or nerves, and/or it's high grade (grade 3) (T1b). The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0). |
|
OR |
||
|
T2 |
The cancer has grown into the corpus spongiosum (an internal chamber that runs along the bottom and into the head of the penis). The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0). |
|
|
IIB |
T3 |
The cancer has grown into the corpus cavernosum (either of 2 internal chambers that run along the top of the shaft of the penis). The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0). |
|
IIIA |
T1-T3 |
The tumor has grown into tissue below the top layer of skin and may have grown into the corpus spongiosum and/or the corpus cavernosum (T1 to T3). The cancer has spread to 1 or 2 nearby inguinal (groin) lymph nodes on the same side of the body (N1). It has not spread to distant parts of the body (M0). |
|
IIIB |
T1-T3 |
The tumor has grown into tissue below the top layer of skin and may have grown into the corpus spongiosum and/or the corpus cavernosum (T1 to T3). The cancer has spread to 3 or more nearby inguinal (groin) lymph nodes on the same side of the body, or to inguinal lymph nodes on both sides of the body (N2). It has not spread to distant parts of the body (M0). |
|
IV
|
T4 |
The tumor has grown into nearby structures such as the scrotum, prostate, or pubic bone (T4). The cancer might or might not have spread to nearby lymph nodes (any N). It has not spread to distant parts of the body (M0). |
|
OR |
||
|
Any T |
The tumor might or might not have grown into deeper layers of the penis or nearby structures (any T). The cancer has spread to nearby lymph nodes in the pelvis, or it has grown outside of a lymph node and into the surrounding tissue (N3). The cancer has not spread to distant parts of the body (M0). |
|
|
OR |
||
|
Any T |
The tumor might or might not have grown into deeper layers of the penis or nearby structures (any T). The cancer might or might not have spread to nearby lymph nodes (any N). The cancer has spread to distant parts of the body (M1). |
|
* The following additional categories are not listed on the table above:
- TX: Main tumor cannot be assessed due to lack of information.
- T0: No evidence of a primary tumor. The N categories are described in the table above, except for:
- NX: Regional lymph nodes cannot be assessed due to lack of information.
Tests for Penile Cancer
- Medical history and physical exam
- Biopsy
- Incisional biopsy - For an incisional biopsy only a part of the changed area is removed. This type of biopsy is often done for lesions that are big, ulcerated (the top layer of skin is missing or the lesion appears as a sore), or that appear to grow deeply into the penis.
- Excisional biopsy - In an excisional biopsy, the entire lesion is removed.
- Lymph node biopsy - lymph nodes can be checked either with fine needle aspiration or by excision.
- Imaging tests -
- Computed tomography (CT)
- CT-guided needle biopsy: CT scans can be used to guide a biopsy needle into an enlarged lymph node or other area that might be cancer spread.
- Magnetic resonance imaging (MRI) - MRI pictures are better if the penis is erect, prostaglandins or inj. papaverine are injected into the penis to make it erect.
- Ultrasound - can help to assess enlarged lymph nodes in the groin/ pelvis.
- Chest x-ray - done to see if the cancer has spread to the lungs.
Surgery for Penile Cancer
Many different kinds of surgery are used to treat penile cancers. Penile-sparing techniques are used as often as possible. These include local treatments and limited surgeries, to save as much of the penis as possible to preserve sexual function, the way the penis looks, and the ability to urinate while standing up.
Circumcision
If the cancer is only on the foreskin, circumcision can often cure the cancer. Circumcision is also done before radiation therapy to the penis. Radiation can cause swelling and tightening of the foreskin.
Simple excision
In simple excision surgery, the tumor is excised, along with some nearby normal skin. If the tumor is small, the remaining skin can then be stitched back together. This is the same as an excisional biopsy.
In a wide local excision, the tumor is removed along with a large amount of normal tissue around it (called wide margins). Removing this healthy tissue makes it less likely that any cancer cells are left behind. If there's not enough skin left to cover the area, a skin graft may be taken from another part of the body and used over the area.
Mohs surgery (microscopically controlled surgery)
This may be an option instead of wide local excision in select cases. Using the Mohs technique, the surgeon removes a layer of the skin that the tumor may have invaded and then checks the sample under a microscope right away (frozen section). If it contains cancer, another layer is removed and examined. This process is repeated until the skin sample doesn't have cancer cells in it. This process is slow, but it means that more normal tissue near the tumor can be saved. It can be used for carcinoma in situ (CIS), and for some early-stage cancers that haven't grown deeply into the penis.
Glansectomy
If the tumor is small and only on the glans (the tip of the penis), part or all of it may be removed. Skin grafts may be used rebuild the glans after surgery.
Partial or total penectomy
This operation removes part or all of the penis. It's the most common and best known way to treat penile cancer that has grown deeply inside the penis. The goal is to remove all of the cancer.
The operation is called a partial penectomy if only the end of the penis is removed (and some shaft remains).
If not enough of the shaft can be saved for the man to urinate standing up without dribbling (at least 2 to 3 cm) , a total penectomy will be done. This means the entire penis is removed, including the roots that extend into the pelvis. The surgeon creates a new opening for urine to drain from the perineum perineal urethrostomy, the man will have to sit to urinate.
For very advanced tumors, sometimes the penis is removed along with the scrotum (and testicles). This operation is called emasculation. Since this operation removes the testicles, which are the body’s main source of the male hormone testosterone, men who have this procedure must take testosterone supplements for the rest of their lives.
Any of these operations can affect a man’s self-image, as well as his ability to have sex.
Lymph node surgery
Sentinel lymph node biopsy (SLNB)
This operation can sometimes help the surgeon see if the groin lymph nodes contain cancer without having to remove all of them. It's most often done when lymph nodes are not enlarged but there's a chance that the cancer reached them. The first lymph node that drains the tumor (called the sentinel node). If the cancer has spread outside the penis, this lymph node is the one the cancer is most likely to go to first. If the sentinel node contains cancer, lymph node dissection or inguinal lymphadenectomy, is done. If the sentinel node does not have cancer cells no further surgery is required. Using this approach, fewer patients need to have many lymph nodes removed. The more lymph nodes that are removed, the higher the risk of side effects such as lymphedema and problems with wound healing.
Inguinal lymphadenectomy (groin lymph node dissection)
Pelvic lymph node surgery
Side effects of lymph node surgery
Lymphedema, wound healing, infection, blood clots, and skin necrosis can occur after lymph node surgery .