What can i do if my mother has a spot on her chest and it may be cancer, should i be worried?

Action, not fear: Do you mean in her lung or chest wall? Rather than being worried, make sure she goes to see a doctor (if she has not done so yet) and follows up his/her recommendations. Hope it is nothing serious. Best to you both.

Suspicious spot: If anyone has a mole that has changed color, shape, or size, it should be evaluted immediately by a board-certified dermatologist. Other suspicious growths, such as non-healing lesions, should be evaluated as well.