Overview of this condition

Testicular cancer is a relatively rare form of cancer. Although it accounts for only 1 percent of cancers in men, it is the most common cancer in men between the ages of 20 and 34. About 75% of cases of testicular cancer occur in men between 20 and 49. Nevertheless, testicular cancer is one of the most treatable forms of cancer, with cure rates approaching 100% if detected early.

The testes, or testicles, are part of the male reproductive system. These glands produce the male sex hormone testosterone, as well as sperm cells. The testes are suspended in a membranous sac (the scrotum) that hangs below the groin and the penis. Behind each gland is the epididymis, a tube that transports the sperm to the urethra for ejaculation through the penis.

Germ cell tumors (GCTs) are growths that occur in the sperm-producing cells. GCTs are the most common form of testicular cancer in males 20-35 years old. In 1995 there were approximately 7,000 new cases of GCTs, resulting in 400 deaths.

There are two main classes of GCTs: seminoma and nonseminoma. In general, seminomas comprise about half of GCTs with nonseminomas comprising the remaining 50%. Seminomas tend to be slower-growing and occur in the fourth decade of life, while nonseminomas occur more often when men are in their 30s. Nonseminomas are generally more aggressive than seminomas. Between 65 and 85% of seminomas are limited to the testes when first diagnosed, while approximately 75% of nonseminomas have already spread to the lymph nodes when diagnosed. There are four types of nonseminomas: embryonal cell carcinomas; teratomas; teratocarcinomas; and choriocarcinomas. These nonseminomas can sometimes occur in combination, and are then called mixed tumors.

Risk Factors

The cause of GCTs is not known; however, there are several notable risk factors. Failure of a testis to descend into the scrotum (cryptorchidism or undescended testicle) increases the risk developing testicular cancer several fold. Similarly, men whose testicles descend after age 6 have a greater risk for testicular cancer. An abdominal cryptorchid testis has a higher likelihood of developing tumor than an inguinal cryptorchid testis. Klinefelter's syndrome, a condition characterized by smallness of the testicles, is also associated with an increased risk of developing GCT.

Although physical injury has been claimed as an initial factor, it is difficult to tell whether the trauma really only called attention to a tumor that was already present. Other factors that have not proven to increase a man's risk for testicular cancer include viral infections, positive HIV status and exogenous estrogen use.

What are the signs and symptoms of the condition?

The most common sign of testicular cancer is a painless swelling or lump in one testis. About a third of the time, a man may experience a dull ache or a feeling of heaviness in the lower stomach, scrotum or groin area.

All men should be familiar with the size and feeling of their testicles, so they can detect any type of change. The American Cancer Society recommends monthly testicular self-examinations (TSE) for men over the age of 15. A TSE is best done after a warm bath or shower when the skin of the scrotum is relaxed. After observing for any changes in appearance, each testis is carefully examined by rolling it between the fingers and thumbs of both hands to check for any lumps.

Since the symptoms commonly associated with testicular cancer can also be caused by infections or illnesses other than cancer, it critical to see a urologist for an accurate diagnosis.