Close monitoring of prostate cancer tumours may make radiation and surgery -- which can cause incontinence and impotence -- unnecessary, a new study has shown.

Prostate cancer is one of the slowest-growing forms of the disease, and many men with tumours may never develop symptoms during their lifetime, meaning that many are treated unnecessarily -- often with serious side-effects.

A study conducted at the University of Gothenburg in Sweden has now shown that many prostate cancer sufferers may dispense with treatment if they opt instead to undergo active surveillance.

This meant constant monitoring of tumour development through regular blood tests and biopsies, taking the step of surgery or radiation only once the tumour starts growing or becomes more aggressive.

"Many men can entirely avoid or at any event postpone the adverse effects associated with curative treatment," researcher Rebecka Arnsrud Godtman said in a statement on Friday.

The study was published in the journal European Urology.

Of 968 men with prostate cancer studied between 1995 and 2010, 440 opted for active surveillance instead of treatment. Most of them had low-risk tumours -- the majority of prostate cancers diagnosed.

Among the group, 60 died but only one from prostate cancer, said the report.