Frolic is a playful word with a happy history. It traces back to the Dutch word vroolijk (merry), which in turn evolved from a Middle Dutch combination of vro (happy) and the adjectival suffix -lijc (-ly).
A normal PSA level is considered to be 4.0 ng/mL (nanograms per milliliter of blood). 1  For men in their 50s or younger, a PSA level should be below 2.5 in most cases.  Older men often have slightly higher PSA levels than younger men.
CEA is a protein marker indicative of several types of cancers, especially colon cancer. The CEA normal levels are different for smokers and nonsmokers. Usually, for adult nonsmokers, the normal CEA levels range from 0 to 2.5 mcg/l.For adult smokers, the levels are slightly higher, and normal levels range from 0 to 5.0 mcg/l. This difference in normal values is because smokers usually produce more CEA than nonsmokers.he CEA normal levels are different for smokers and nonsmokers. Usually, for adult nonsmokers, the normal CEA levels range from 0 to 2.5 mcg/l. For adult smokers, the levels are slightly higher, and normal levels range from 0 to 5.0 mcg/l.