What is testicular cancer?
Testicular cancer is an abnormal, uncontrolled growth of cells that form a tumor on one or both testes. Men have two testicles (testes, gonads) that are located in the scrotum, a pouch of loose skin found below and at the base of the penis. About the size of golf balls, the testicles are responsible for producing sperm and male hormones (mainly testosterone) that regulate reproductive organ development and the adult male maturation process.
Testicular cancer is the most common cancer in males between 20 and 35 years of age. According to the American Cancer Society, about 8,500 men are diagnosed with testicular cancer in the United States each year, and about 350 men die of it. Caucasian males are at a greater risk than are those of African, Hispanic, or Asian descent, although the cause for this additional risk is not known. Other risk factors include undescended testicles (cryptorchidism), gonadal dysgenesis (abnormal development of the testes), Klinefelter syndrome (a sex chromosome disorder), and a family or personal history of testicular cancer. Those individuals who handle pesticides, leather workers, miners, oil well workers, and HIV-positive persons also appear to be at higher risk.
Germ cell tumors account for about 94% of testicular cancers. These cancers are separated into two groups, seminomas (30%) and nonseminomas (70%). Seminomas are less aggressive, tend to grow slowly, and usually do not metastasize. Nonseminomas include four types: yolk sac tumors, teratomas, embryonal carcinomas, and choriocarcinomas. They often occur earlier in life and grow and spread more quickly than seminomas.
About 4-5% of all (and 20% of children's) testicular cancers are stromal tumors, forming in the tissues that support the testes. Since this tissue also produces hormones, these tumors may secrete estradiol, a form of the female hormone estrogen that can be responsible for gynecomastia in males.
While testicular cancer is one of the most curable forms of cancer, with a cure rate in excess of 90%, most types can spread if left unchecked, invading and damaging the other testicle, and metastasizing to the lymph nodes or other body organs, such as the lungs. Early detection and treatment is crucial to a favorable outcome.