To reduce their risk for prostrate cancer men over 40 are encouraged to have an annual PSA test.
Explanation; PSA test measures the level of PSA in a man's blood. Prostrate specific antigen is a protein by normal, as well as malignant, cells of the prostrate gland. The blood level of PSA is often elevated in men with prostrate cancer.
If the resulting daughter cells are too damaged to undertake further cell divisions, the mutation would not be propagated and no harm comes to the organism