What is penile cancer?
Penile cancer is a rare type of cancer which usually occurs on the skin of the penis or inside the penis. Penile cancer most commonly affects men above the age of 50. Penile cancer develops either above or within the penis, which consists of several different types of cells.
The cancer starts on the skin cells of the penis and then spreads in to the inner side. It can be treated if diagnosed early. In the United States, penile cancer affects almost 2,100 men every year. All the types of penile cancers are initially present on the skin of the penis.
Most common types of penile cancers usually appear in the squamous cells (flat skin cells). Generally, this type of cancer starts in the glands of the penis present at its tip or on the foreskin of uncircumcised men.
Penile cancer facts
Some important facts about penile cancer are:
- Penis cancer is a disease characterized by the formation of malignant (cancer) cells that develop in the tissues of the penis.
- Penile cancer is usually found on the glans or foreskin of the penis but sometimes on the shaft of the penis also.
- Generally, all penile cancers begin in the skin of the penis.
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Types of penile cancers
Depending on the type of cells involved, following types of penile cancers can occur:
Squamous cell penile cancer
This type of penile cancer has been found in more than 90% of cases and usually starts in the cells which cover the surface of the penis.
Carcinoma in situ (CIS)
This is a particular type of squamous cell cancer in which only the cells present in the skin of the penis are affected. It cannot spread any deeper.
Adenocarcinoma
It is a type of penile cancer that starts in the sweat-producing glandular cells of the penis.
Melanoma of the penis
This is a type of penile cancer which develops from the skin cells that are responsible for providing color to the skin of penis.
Signs and symptoms of penile cancer
Most common symptoms of penile cancer are:
- Changes in the skin of penis
- Thickening of the foreskin or skin of the penis making it difficult to drawback the foreskin called as Phimosis
- Changes in color of skin on the penis
- Presence of lumps on the penis
- Presence of a rash or small crusty bumps on the penis resembling like an unhealed scab
- Bluish-brown growths on the penis
- Smelly discharge below the foreskin
- Bleeding sores on the penis
- Swelling of the penis especially at the end
- Lumps beneath the skin in the groin area
- Extreme and unexplainable pain in the shaft or tip of the penis
- Itching and burning of the penis
Causes of penile cancer
The exact cause of penile cancer is not known yet but following risk factors have been found to increase the chances of getting it:
Human papilloma virus
Human papilloma virus (HPV), which has more than 100 types and some of them cause genital warts.
Age
Penile cancer hardly affects men under the age of 40 and is most commonly found in men above the age of 50.
Smoking
Chemicals found in cigarettes can damage cells of the penis and thereby increase the risk of getting penile cancer.
Phimosis
Phimosis increases the chances of developing infections like balanitis. Repeated infections have been linked to a higher risk of developing some types of penile cancers because the infections weaken the immune system.
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Stages of penile cancer
The different stages of penile cancer are:
Stage 0 penile cancer or carcinoma in situ (CIS)
At this stage, the cancer is present only in the top layers of the skin of the penis.
Stage 1 penile cancer
In this stage, the cancer has grown into the connective tissues present below the skin of the penis but has not grown into the blood vessels and lymph vessels (lymphovascular invasion). The cancer cells look and behave almost like normal cells in the penis.
Stage 2A penile cancer
The cancer has grown either into the connective tissues present below the skin of the penis as well as into the blood vessels and lymph vessels (lymphovascular invasion). Besides this, the cancer cells look and behave entirely different from normal cells in the penis.
Stage 2B penile cancer
Cancer at this stage has grown into the corpus cavernosum (upper chambers of the shaft which makes most of the penis) as well as sometimes into the urethra.
Stage 3A penile cancer
Cancer has spread to one of the lymph nodes present in the groin region called inguinal lymph nodes. The lymph node becomes movable and can be felt.
Stage 3B penile cancer
Cancer has spread to 2 or more lymph nodes in the groin and are able to move when felt by a doctor.
Stage 4 penile cancer
At Stage 4, penile cancer has grown into a nearby structure other than the urethra. The cancer has spread to lymph nodes in the groin followed by the formation of an immovable lump called a fixed nodal mass. Besides this the cancer has spread to pelvic lymph nodes as well.
Sometimes the cancer spreads to other parts of the body like lungs, liver and bones called distant metastasis or metastatic penile cancer.
Recurrent penile cancer
Recurrent penile cancer means returning back of the cancer after its treatment. If the cancer comes back to the same place from where it had started, it is called as local recurrence. If it comes back in nearby tissues or lymph nodes from where it first started, it is called regional recurrence and if it comes back into some other part of the body, it is called as distant metastasis or distant recurrence
Diagnosis of Penile cancer
Many tests are used by doctor in order to diagnose penile cancer and also to check if the cancer has spread to any other part of the body from its origin (metastasis). Tests can also help a doctor in finding out the best treatment.
Mostly a biopsy is the only sure way for the doctor to identify any cancer affected area. In a biopsy, a small tissue sample is taken for testing in laboratory. However if for some reason biopsy is not possible then other tests can be used.
Following factors are taken into consideration before choosing any diagnostic test:
- Suspected cancer type
- Signs and symptoms of the patient
- Age and medical condition of the patient
Apart from physical examination, following diagnostic tests can be used for diagnosing penile cancer:
Biopsy
If there is any unusual change found on or in a man’s penis or nearby lymph nodes, a biopsy test is required to know about the reason of change. In a biopsy test, a small amount of tissue is removed for analyzing under a microscope. Other tests can also be used to find out the cancer, but only a biopsy provides definite diagnosis.
If cancerous cells are present in a tissue sample, then the biopsy is called positive for cancer and if no cancer cells are found, then the biopsy is called benign or negative for cancer. If a pathologist is not able to distinguish the cancerous cells, the biopsy is called indeterminate or non-diagnostic.
Types of biopsies
Following are the types of biopsies that can be used for penile cancer:
Punch biopsy or elliptical excision
This type of biopsy is used to find out an abnormal change on the penis. In a punch biopsy, a sharp round surgical tool to is used to remove a circular piece of tissue while as in an elliptical excision, a scalpel or some other tool is used to cut out a piece of tissue.
Fine needle aspiration
This is a specific type of biopsy in which the skin is anesthetized with the help of a topical medication that blocks the sensation of pain. Another medicine is then injected into the tumor area to prevent pain in tissues underneath. Then, a thin needle is inserted into the tumor to remove some cells and fluids. This procedure is repeated 2 or 3 times to collect samples from different areas surrounded by the tumor.
Sentinel lymph node biopsy
Sentinel lymph node biopsy is used to find out if cancer cells have spread to lymph nodes present near the penis. In this technique, one or a few sentinel lymph nodes are removed to check for cancer cells.
Sentinel lymph nodes are the first lymph nodes in which the tumor drains its lymph fluid. In case of penile cancer, the sentinel lymph nodes are present just under the skin in the groin. The presence of cancer cells in lymph nodes indicate that the cancer can spread to other nearby lymph nodes or to other parts of the body. Even if cancer cells are absent during the sentinel lymph node biopsy, chances are still that the cancer has spread.
Inguinal (groin) lymph node dissection
This is one of the most accurate way to find out if the penile cancer has spread to any lymph nodes near the penis or not. This procedure involves removal of lymph nodes near the penis for checking cancer. This procedure is more informative as compared to the removal of a single lymph node or a group of lymph nodes. However, after this procedure, some men may face many problems like poor wound healing, long-lasting and severe leg swelling, called lymphedema.
X-ray
An x-ray is used to create a picture of the structures present inside the body by using a small amount of radiation.
Computed tomography (CT or CAT) scan
A CT scan is used to create a 3-dimensional picture of the inner side of the body with the help of x-rays taken from different angles. These images are then combined with the help of a computer into a detailed, cross-sectional view that helps to show abnormalities or tumors. A CT scan is also used to measure the size of a tumor.
Magnetic resonance imaging (MRI)
An MRI uses magnetic fields instead of x-rays to produce detailed images of the body. MRI is used to measure the size of tumor.
Treatment of penile cancer
A team of doctors and other professionals called a multidisciplinary team (MDT) usually discusses the best treatment and care for penile cancer patients based on the following:
- Location of cancer
- How far the cancer has spread (stage of the cancer)
- Cancer type
- Grade of cancer (appearance under microscope)
- General health and fitness level of patient
The main treatments for penile cancer are:
- surgery
- radiotherapy
- chemotherapy
- chemoradiotherapy
A patient may require one or more of these treatments depending on the stage of the cancer.
Treatment of penile cancer by stage
Stage 0 penile cancer or carcinoma in situ (CIS)
Various treatments are available to treat penile CIS which aim to keep the penis looking and working normally. The treatment includes:
- Chemotherapy creams like fluorouracil (5FU) or a cream called imiquimod which uses the immune system to fight against cancer
- Laser therapy
- Cryotherapy
- Glans resurfacing surgery in which the top layers of glans tissue and tip of the penis are removed and then enclosed with a skin graft
Treatment for stage 1 penile cancer
The main treatment for stage 1 penile cancer is surgery, either alone or with a combination of other treatments. There is a removal of the foreskin (circumcision) if the cancer is only in the foreskin. However, following treatments are available if the cancer is present somewhere else on the penis:
- wide excision i.e, removal of the cancer and surrounding areas of tissues
- Partial penectomy i.e, removal of some part of the penis
- Radiotherapy
- Laser treatment
Treatment for stage 2 penile cancer
Surgery is usually the main treatment for stage 2 penile cancer and involves the removal of either some part of the penis or removal of the whole penis.
Radiotherapy followed by surgery is recommended if some cancer cells have remained afterwards.
The lymph nodes in the groin are checked with a test called sentinel lymph node biopsy to check if cancer cells have spread there or sometimes the surgeon may remove the lymph nodes too.
Treatment for stage 3 penile cancer
This stage mainly involves the removal of some part of the penis or removal of the whole penis. In some patients, either chemotherapy alone or chemotherapy along with radiotherapy is done before the surgery.
Treatment for stage 4 penile cancer
This stage is usually characterized by the presence of cancer in the nearby tissues and is usually treated by surgery. In some patients prior to surgery, chemotherapy or chemotherapy along with radiotherapy is done so as to shrink the tumor. This stage also involves removal of lymph nodes in the groin area called as inguinal nodes on both sides.
Cancer ahead of nearby lymph nodes or in pelvic lymph nodes
Cancer in such cases involves surgical removal of the whole penis as well as the groin on both sides. The lymph nodes inside the pelvis are also removed. Radiotherapy and chemotherapy to the lymph node areas is also done.
Cancer in distant organs or tissues
Treatment in such cases usually aims to control the cancer and maintain a good quality of life. Surgery is done to remove as much of the cancer in the penis as possible. Also radiotherapy may be given to the patients for shrinking the cancer.
Treatment for recurrent penile cancers
Treatment for recurrent penile cancers depends on where the cancer comes back and the treatment used before. For example:
- Cancers that come back in the penis require further surgery to remove the cancer cells followed by radiotherapy.
- Cancers that come back in the lymph nodes require surgical removal of the nodes using radiotherapy or chemotherapy.
- Cancers that come back in other parts of the body are treated by either chemotherapy or radiotherapy.
