The most common form of penile cancer is squamous cell carcinoma, cancer that begins in the flat cells lining the penis. Cancer of the urethra, the tube through which urine empties from the bladder, is very rare. According to the National Cancer Institute, just over 1,500 new cases will be diagnosed annually in the U.S.
The penis is a rod-shaped male reproductive organ that passes sperm and urine from the body. It contains two types of erectile tissue (spongy tissue with vessels that fill with blood to create an erection):
- Corpora cavernosa: The two columns of erectile tissue that form most of the penis.
- Corpus spongiosum: The single column of erectile tissue that forms a small portion of the penis. The corpus spongiosum surrounds the urethra (the tube through which urine and sperm pass from the body).
The erectile tissue is wrapped in connective tissue and covered with skin. The glans (head of the penis) is covered with loose skin called the foreskin. At birth or soon after, many men undergo a circumcision, a surgery to remove all or most of the foreskin.
Metastatic penile cancer
When penile cancer spreads beyond the penis, it is considered metastatic disease. At this point, the cancer becomes more difficult to treat. The three ways that cancer spreads in the body are:
- Through tissue: Cancer invades the surrounding normal tissue.
- Through the lymph system: Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
- Through the blood: Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the original (primary) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if penile cancer spreads to the bladder, the cancer cells in the bladder are actually penile cancer cells. The disease is metastatic penile cancer, not bladder cancer.
Symptoms
Early detection is the best way to combat this disease, so being aware of the symptoms is important, especially if you have been infected with HPV (human papillomavirus), a sexually transmitted disease that increases your risk. It’s important to seek immediate consultation if the symptoms listed below are present. However, these symptoms do not always mean cancer; other conditions may have similar signs.
Symptoms of penile cancer include:
- Persistent redness, irritation, or a sore on the penis
- Discharge from the penis
- A lump on the penis