What Is Testicular Cancer

Testicular cancer is a disease in which cells become malignant (cancerous) in one or both testicles.

The testicles (also called testes or gonads) are a pair of male sex glands. They produce and store sperm and are the main source of testosterone (male hormones) in men. These hormones control the development of the reproductive organs and other male physical characteristics. The testicles are located under the penis in a sac-like pouch called the scrotum.

Based on the characteristics of the cells in the tumor, testicular cancers are classified as seminomas or nonseminomas. Other types of cancer that arise in the testicles are rare and are not described here. Seminomas may be one of three types: classic, choriocarcinoma, embryonal carcinoma, teratoma, and yolk sac tumors. Testicular tumors may contain both seminoma and nonseminoma cells.

Testicular cancer accounts for only 1 percent of all cancers in men in the United States. About 8,000 men are diagnosed with testicular cancer, and about 390 men die of this disease each year (1). Testicular cancer occurs most often in men between the ages of 20 and 39, and is the most common form of cancer in men between the ages of 15 and 34. It is most common in white men, especially those of Scandinavian descent. The testicular cancer rate has more than doubled among white men in the past 40 years, but has only recently begun to increase among black men. The reason for the racial differences in incidence is not known.

Overview

Testicular cancer develops in the testicles (testes), the male reproductive glands. The testicles are located in the membranous pouch below the penis (scrotum) and are suspended from the body by the spermatic cord. They produce male reproductive cells (sperm) and testosterone. Testicular cancer is treated successfully in more than 95% of cases.

Anatomy

The testicles are primarily made up of a mass of seminiferous tubules in which sperm develop. The tubules are lined with Sertoli cells, which protect and supply nutrients to developing sperm. Sertoli cells also secrete the hormone inhibin, which is involved in the regulation of sperm production.

Leydig cells, located in tissue between the seminiferous tubules, secrete testosterone and androsterone. These hormones stimulate the development of male sex organs, beard growth, muscle mass, and deepening of the voice.

Incidence and Prevalence

Incidence of testicular cancer is rising. According to the American Cancer Society, approximately 7600 cases are diagnosed and about 400 men die of the disease each year in the United States. The disease is most prevalent in men between the ages of 18 and 32 and is approximately 5 times more common in Caucasians than African Americans. Germany, Scandinavia, and New Zealand have the highest incidence of testicular cancer and Asia and Africa have the lowest.