LONDON (Reuters) - Most testicular cancer patients who try to father children after completing their treatment succeed, scientists said Tuesday.

Men who have surgery to remove the tumour have the least problems but even patients who have radiotherapy and chemotherapy are able to have children.

"The vast majority of men, after testicular cancer treatment, can go on and have a family as normal," said Dr Robert Huddart of The Institute of Cancer Research in London.

But he added that there is a portion of patients, regardless of what treatment they have had, who will have difficulty having children because the illness and low fertility are associated.

Cases of the cancer, which affects mostly men in their late 20s and early 30s, have risen rapidly in recent decades. In some countries it is the most common cancer among young men. About 50,000 new cases are reported worldwide each year.

Huddart and his colleagues studied 700 patients who had been treated for the disease between 1982-1992 and asked them to complete a questionnaire about their health and fertility. Their findings are published in the British Journal of Cancer.

Of the 200 patients who admitted they were trying to have a child, 77 percent were successful. An additional 10 percent fathered children through fertility treatment.

Men who had surgery and no follow-up treatment had an 85 percent success rate, followed by 82 percent for patients following radiotherapy and 71 percent after chemotherapy.