Men’s reproductive cancers are abnormal growths of malignant cells in the organs of the male reproductive system. The main types of men’s reproductive cancers include prostate cancer, testicular cancer and penile cancer.

The organs of the male reproductive system are located in and around the lower part of the pelvis. The penis, located between the legs, contains a shaft of spongy tissue and the tip, or glans. At birth, a fold of skin called the foreskin covers the glans. For cultural, religious or hygienic reasons, the foreskin may be removed in a procedure called a circumcision. The inside of the penis consists of spongy tissue that swells with blood during an erection.

The urethra is a tube that runs the length of the penis. It then passes through the prostate to the urinary bladder. The urethra carries urine and semen at different times. The prostate gland is located in front of the rectum and below the bladder and surrounds the urethra. As men age, the prostate often enlarges and constricts the urethra, making urination more difficult.

The testicles (also called testes) are two oval glands, about 2 inches (5 centimeters) long and 1 inch (3 cm) in diameter when mature. The testicles produce sperm cells and hormones such as testosterone. They are located inside the scrotum, a pouch outside the pelvis behind the penis.

Ducts throughout the area transport fluids such as semen, the fluid that contains sperm cells. Sperm cells produced in the testes move through the epididymis and the vas deferens through the prostate. Sperm then passes into the seminal vesicles and then into the urethra during ejaculation. Other fluids produced in the prostate and seminal vesicles mix with the sperm cells in the semen to protect them. Semen in the seminal vesicles leaves the body through the penile part of the urethra during ejaculation. The urethra is also the pathway used to move urine out of the body from the bladder through the penis.

Men’s reproductive cancers begin when cells in the prostate, testicles or penis grow out of control because of damage to DNA. DNA is genetic material present in every cell in the body. Normally the body can repair damage to DNA. When it cannot, cells reproduce abnormally and become malignant. Of the cancers that affect the male reproductive organs, prostate cancer is by far the most common.

Male reproductive cancers vary according to the kinds of cells affected. These cancers include:

• Adenocarcinoma. Cancer in glandular cells. These cells account for most prostate cancers.
  
  
• Germ cell tumors. Cancer in germ cells, normally found in the gonads (sex organs). While these cells can travel and cause tumors in other body areas, they are most frequently associated with testicular cancer in men and ovarian cancer in women.
  
  
• Squamous cell carcinoma. Develops from flat, scaly epithelial cells in the skin and the inner linings of the body. This accounts for most penile cancer and some prostate cancer.
  
  
• Sarcoma. Develops in the blood vessels, smooth muscle and other connective tissues. Sarcomas are rare in men’s reproductive cancers.
  
  
• Small cell carcinoma. Small round cancer cells that develop from nerve-like cells. Small cell carcinoma occurs infrequently in the prostate. It is more common in the lungs and can also affect the ovaries, cervix and other organs.
  
  
• Melanoma and basal cell carcinoma. Skin cancers that occasionally affect the penis.

In addition to these primary men’s reproductive cancers, there are secondary cancers that have spread from somewhere else. These are considered to be a metastasizing cancer of the organ where they started. For example, lymphoma or prostate cancer can spread to the testicles.

Staging men’s reproductive cancers takes into account the extent of the primary tumor, whether the cancer has spread to nearby lymph nodes, and whether there is metastasis to distant structures.

In 2007, the American Cancer Society estimates that there will be more than 228,000 new cases of men’s reproductive cancer diagnosed. Nearly 219,000 of these cases will be prostate cancer – the most common of the men’s reproductive cancers. When detected and treated early, this type of cancer has a good prognosis for survival.