Should 5mm nodule on lung be removed?

Probably not.: 5mm lung nodules are routinely followed with ct. How often is determined by your risk for lung cancer (smoking history etc.).

No, almost NEVER: A 5 mm lung nodule, even in a high risk person (heavy long time smoker) has a (much) less than 1% chance of being cancer as opposed to a benign scar or 'granuloma'. Nobody should be doing surgery to remove a 5 mm nodule except in the rarest of circumstances, too complicated to discuss in 400 characters.