Testicular cancer may be susceptible to heat therapy

Heat sensitivity may make testicular cancer, and possibly other malignancies, more susceptible to standard treatments and die off more readily, according to a commentary in last week’s JAMA (2006; 296:445-8).

The authors, from Johns Hopkins University in Baltimore, found scientific evidence spanning over 30 years to explain why some testicular cancer patients, such as Tour de France winner Lance Armstrong, show better survival than patients with other advanced cancers. When Armstrong’s cancer cells spread from the testes into warmer regions of the body, scientists believe the temperature boost may have weakened protein scaffolding within the cancer cells’ nucleus. This made the nuclear DNA more vulnerable to chemotherapy and radiation.

“If we understand how heat may naturally help kill testicular cancer cells, then perhaps we can make it happen in other solid tumors,” said co-author Robert Getzenberg, PhD. “More than 80% of men with widespread testicular cancer can achieve a cure. In other cancers, the cure rate is far less.”

An unrelated study by the Robert Wood Johnson Medical School, New Brunswick, NJ, may support the theory. The researchers studied men with undescended testes. Without treatment, infertility is common and further examination of the men’s sperm showed that the sperm cells’ nuclear matrix was ruined (Urology 2000; 56:1068-70). Washington University, St. Louis, scientists already found that nuclear matrixes are heat sensitive.

“The warmer region of the pelvis made the nuclear matrix in the cells that make sperm unstable and prone to death,” said Theodore DeWeese, MD, another co-author of the Johns Hopkins article. “If we give a cancer cell more heat to completely disrupt its matrix, and then add toxic drugs and radiation, the cancer cell may be so disabled that it won’t be able to replicate and will die.”

Preliminary research is under way at Johns Hopkins to refine heat delivery systems and test them in prostate cancer animal models.