Penile cancer is a rare type of malignancy that develops in the penis. The penis is the male sex organ comprised of four main parts: the head of the penis (glans), body/shaft, foreskin (moveable layer of skin covering the glans), and the frenulum (small tag of skin under the penis between the foreskin and the shaft).
The penis has functions in both the urinary and reproductive systems. In the urinary system, the penis contains the urethra, which is a thin tube that carries urine from the bladder to the outside of the body. In the reproductive system, blood flows to the penis during sexual arousal to make it erect, allowing for sexual intercourse and the passage of sperm from the testicles to the outside of the body.
Penile cancers are generally diagnosed in men over 50, however, it can affect anyone with a penis – including men, teenagers, transgender women, non-binary individuals, and intersex people – at any age.
Types of Penile Cancer
There are several types of penile cancer, that are categorised by which types of cells the cancer develops from.
Squamous Cell Carcinoma (SCC)
Squamous cell carcinoma’s (SCCs) are the most common type of penile cancer. This type of cancer develops from the squamous cells that cover the surface of the penis. SCC penile cancer often develops in the foreskin of uncircumcised men or in the glans, but can develop in the skin of the shaft as well. While this type of cancer can be aggressive, it can have a good prognosis when caught early.
Carcinoma in situ (CIS)/penile intraepithelial neoplasia (PeIN)
Carcinoma in situ (CIS), also known as penile intraepithelial neoplasia (PeIN), is the earliest stage of penile SCC. It is the most common precancerous condition of the penis, and only appears in the very top layer of skin cells.
Basal Cell Carcinoma (BCC)
Basal cell carcinoma (BCC) of the penis is a rare subtype of penile cancer, that is often classified as a type of skin cancer. They develop from the basal cells in the skin, which are located under the squamous cells. BCCs are not usually aggressive, are slow growing, and usually have a good prognosis.
Adenocarcinoma
A penile adenocarcinoma is a very rare subtype of penile cancer that develops from the sweat glands in the penis. Due to the rarity of the disease, there has been limited research done into the prognosis of this disease.
Melanoma
Penile melanomas are a rare subtype of penile cancer that develop from melanocytes, which are the cells that give skin its pigmentation or colour. While melanomas generally develop in areas exposed to the sun, they can rarely develop in areas not exposed to the skin. Penile melanomas can be aggressive, but the prognosis can be good when caught early.
Penile Sarcoma
Penile sarcomas are the rarest subtype of penile cancer. They often develop in deeper tissues of the penis, such as blood vessels, muscle, fat, or connective tissue, and can be very aggressive. Due to the rarity of this subtype, there has been limited research done into the prognosis of this disease.
Treatment
If penile cancer is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodes) indicates whether the cancer has spread to nearby lymph nodes.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for penile cancer may include:
- Surgery, potentially including:
- Circumcision (removal of the foreskin).
- Simple excision (removal of the tumour and a small amount of nearby tissue).
- Wide local excision (removal of the tumour and a larger portion of nearby tissue).
- Glans resurfacing (removal of the top layer of tissue on the glans. Skin graft may also be required to replace tissue taken).
- Partial glansectomy (removal of part of the glans).
- Total glansectomy (complete removal of glans).
- Partial penectomy (removal of part of the penis and reconstruction of the urethra).
- Total penectomy (complete removal of penis and reconstruction of urethra).
- Lymphonodectomy (removal of affected lymph nodes).
- Chemotherapy, potentially including topical chemotherapy.
- Radiation therapy, potentially including:
- External beam radiation therapy.
- Brachytherapy.
- Laser therapy.
- Photodynamic therapy.
- Cryotherapy.
- Clinical trials.
- Palliative care.
For more information on the treatment options, please refer to the Rare Cancers Australia Treatment Options page.
Risk factors
While the causes of penile cancer remain unknown, the following factors may increase your risk of developing the disease:
- Being infected with the Human papillomavirus (HPV).
- Not being circumcised.
- Having a history of smoking.
- Having a weakened immune system.
- Being over 50 years old.
- Certain skin conditions, such as:
- Psoriasis.
- Lichen Sclerosis.
- Phimosis.
- Being infected with the human immunodeficiency virus (HIV).
- Being infected with the acquired immunodeficiency syndrome (AIDS).
- Having precancerous lesions, such as CIS and/or PeIN.
- Previous exposure to ultraviolet (UV) radiation.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Early symptoms
Early symptoms of penile cancer may include:
- A growth or sore on any area of the penis that doesn’t go away after a few weeks.
- Unusual bleeding from the penis and/or under the foreskin.
- Foul-smelling discharge from under the foreskin.
- A lump on any area of the penis.
- Changes in colour of penile skin/foreskin.
- Thickening of penile skin/foreskin.
- Unexplained pain in any area of the penis.
- Swelling of the tip of the penis.
- Persistent rash on any area of the penis.
- Unexplained lumps in the groin region.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis/diagnosing
If your doctor suspects you have penile cancer, they will order a range of diagnostic tests.
Imaging & blood tests
The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), and/or positron emission tomography (PET scan), depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and look for signs of metastasis. Additionally, a blood and urine test may also be taken to assess your overall health and help guide treatment decisions.
Biopsy
Once the location(s) of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. This can be done by either a punch biopsy, a fine needle aspiration, and/or a lymph node biopsy. The samples are then analysed for cancer cells.
Prognosis (Certain factors affect the prognosis and treatment options)
While it is not possible to predict the exact course of the disease, your doctor may be able to give you a general idea based on stage, rate/depth of tumour growth, susceptibility to treatment, age, overall fitness and medical history. Generally, early-stage penile cancers have good prognosis and survival rates. However, if the cancer is advanced and has spread, the prognosis may not be as good and there may be a higher risk of cancer recurrence.
References
Some references are to overseas websites. There may be references to drugs and clinical trials that are not available here in Australia.