Genetic Link for Testicular Cancer Found

Researchers have found a gene that increases the risk of testicular cancer by as much as 50 times.

The gene is being called TGCT1 and appears on the X chromosome. Since it is on the X chromosome men get if from their mothers. Moms get the suspect gene from either their mother or father.

Mike Stratton of Britain's Institute of Cancer Research, which sponsored the study, says the TGCT1 gene is likely to be one of "an unknown number" of genes that predispose men to testicular cancer. Another researcher, Doug Easton, said the next step was to identify and map the gene. Such mapping would help in the development of screening tool for men at high risk for developing testicular cancer.

The scientists are reporting their findings in the Feb. 2000 issue of the journal Nature Genetics. The researchers studied 134 families they found with the aid of the International Testicular Cancer Linkage Consortium. The consortium provides data on 134 families from Ireland, Australia, Canada, Norway and Germany. In each family, there were two or more cases of testicular cancer. In 87 of the families, two brothers had testicular cancer. That finding lead researchers to the genetic link, which is passed down from mothers.

Cancer of the testicle (also called the testis), a rare kind of cancer in men, is a disease in which cancerous (malignant) cells are found in the tissues of one or both testicles. Cancer of the testicle is the most common cancer in men 15 to 35 years old. Men who have an undescended testicle (a testicle that has never moved down into the scrotum) are at higher risk of developing cancer of the testicle than other men whose testicles have moved down into the scrotum. This is true even if surgery has been done to place the testicle in the appropriate place in the scrotum.

There are four primary treatments for patients with testicular cancer: surgery, radiation therapy, chemotherapy and bone marrow transplantation.

Surgery is a common treatment of most stages of cancer of the testicle. A doctor may take out the cancer by removing one or both testicles through an incision (cut) in the groin. This is called a radical inguinal orchiectomy. Some of the lymph nodes in the abdomen may also be removed (lymph node dissection).

SOURCE: The journal Nature Genetics, Feb. 2000.