Experts have advised the government to end unnecessary and drastic treatment for prostate cancer.
In the future, men diagnosed with low-grade cancer should be offered regular monitoring until their illness shows signs of becoming threatening, rather than automatically receiving surgery or radiotherapy, the National Institute for health and Clinical Excellence (NICE) said.
Although prostate cancer kills 10,000 men in the UK each year, many nonaggressive cancers are slow growing and may have no effect on a patient for 15 years or more.
Since the disease is mainly diagnosed in older men, these patients often reach the end of their normal lives without being unduly affected by their condition.
But radical treatments such as removal of the prostate gland or radiotherapy can have serious and uncomfortable side-effects, including impotence and urinary incontinence.
The new NICE guidelines for the first time advocate an "active surveillance" policy to be universally adopted in England and Wales for men with low-risk, localised prostate cancer.
Under active surveillance, no immediate action is taken to treat the patient, who instead is regularly tested for PSA (prostate specific antigen) in his blood.