Large numbers of men who undergo treatment for testicular cancer suffer serious and long-term side effects or illness, according to a study conducted by researchers from the University of Oslo and published in the journal BJUI.

In the past, the rate of long-term side effects has not been well known because doctors are only required to report side effects that require medical intervention or threaten the patient's life.

"Current patients with testicular cancer should be informed about the risk of short-term and particularly long-term side-effects of their highly effective treatment" lead author Sophie D. Fossa said. "It is important to focus on reducing risks through healthy lifestyle choices and consider important issues like preserving future fertility."

Reviewing 40 studies published between 1990 and 2008, the researchers found that a full 30 percent of patients undergoing cisplatin-based chemotherapy may suffer from damage to their sensory nerves, while 20 percent of testicular cancer survivors suffer from hearing loss or ringing in their ears. The rate of chronic fatigue in survivors is 17 percent, which is twice as high as in the general population. As many as 25 percent of survivors suffer long-term damage to their circulatory systems. Testicular cancer survivors also have 1.8 times the general risk of developing another form of cancer.

"Gastrointestinal side-effects are common during both chemotherapy and radiotherapy and chemotherapy carries added risks like infections and blood clots," Fossa said. "Long-term problems include secondary cancers, heart problems, and conditions related to lower hormone levels."

Testicular cancer treatments increase a man's risk of pulmonary complications, death from heart complications, fertility reduction and dry ejaculation.

The best way to reduce the risk of dangerous side effects, Fossa said, is to maintain an active lifestyle and healthy weight, avoid tobacco, and for doctors to "provide adequate follow-up for patients who could develop life-threatening toxicity."

Although side effects of cancer treatment can pose serious risks throughout a person's lifetime, most patients receive only five to 10 years of follow-up care, at most.