Important research into testicular cancer is being done in many university hospitals, medical centers, and other institutions around the country. Each year, scientists find out more about what causes the disease, how to prevent it, and how to improve treatment.
Recently, researchers have found inherited variations in two genes called c-KIT ligand (KITLG) and sprouty 4 (SPRY4) that appear to increase a man's risk of developing testicular cancer. Another study found that variants of 3 other genes, DMRT1, TERT, and ATF71P, may also increase the risk of testicular cancer. These findings may help identify men at higher risk, but they need to be studied much more.
Scientists are also studying the changes in DNA of testicular cancer cells to learn more about the causes of this disease. Their hope is that improved understanding will lead to even more effective treatment. Certain gene mutations found in the testicular cancer cells have been linked to resistance to chemotherapy and predict poor outcomes. These findings may help individualize treatment better and help find new drugs to treat testicular cancer that can target these gene mutations. A better understanding of the genetic changes will help doctors decide which patients need further treatment and which can be safely treated with surgery alone.
Clinical trials have refined doctors' approaches to treating these cancers and are expected to answer additional questions. For example, studies have identified factors to help predict which patients have a particularly good prognosis and may not need lymph node surgery or radiation therapy. Studies also have found unfavorable prognostic factors that suggest certain patients may benefit from more intensive treatment.
A large amount of work is being done to try to limit the long-term toxicities of treatment while maintaining the cure rate. Doctors want to be able to predict better whose cancer is more likely to recur and then base the amount of therapy on this, thereby not under- or over- treating anyone. One study reported good results by individualizing treatment in men with metastatic testicular cancer based on the decline of tumor marker (AFP and HCG) levels after chemo, giving more intense treatment to those with a slower decline.
New drugs and new drug combinations are being tested for patients with recurrent cancer. Stem cell transplantation is being studied as a strategy for helping men who have tumors with a poor prognosis tolerate more intensive chemo. And chemo combinations are being refined to see if eliminating certain drugs, replacing them with others, or lowering doses can reduce side effects for some men without reducing the effectiveness of treatment.
As more and more young men are surviving testicular cancer, fertility has become an increasingly important consideration. Advances in assisted reproduction methods such as in vitro fertilization have made fatherhood possible for testicular cancer survivors, even if their sperm counts are extremely low. In some cases, sperm cells removed from a testicular biopsy specimen can be successful when other options have failed.