The Army has been testing military recruits, a low-risk group, for two years.

The low-risk group was observed without further treatment unless the patient had life- or organ-threatening tumors.

The low-risk group was observed without further treatment in most cases.

They also said students considered themselves to be in a low-risk group for the disease.

But chemotherapy did not help women in the low-risk group: their recurrence rate was about 5 percent, with or without the drugs.

They also note that in a low-risk group like engaged couples, a large proportion of the positive results are false.

While it is possible to identify accurately those patients in low-risk groups the positive predictive value of many tests remains poor.

Another study showed, however, that 43% of the tested infected people were from low-risk groups.

Four Down's syndrome babies were also born to mothers who had been told they were in the low-risk group.

"Early treatment of high cholesterol in low-risk groups may not improve outcomes," he said.