Hi - At age 17, it would be nearly impossible for you to have breast cancer. Please read our letter to teens, and our teen guide to breast development; I think both of them will relieve your worries. The itchy nipples are probably a hormonal issue; and the lump, since it hasn't changed in a year, might be just a natural part of your breast. As you get older, it's good to report any breast changes to your doctor, as you notice them; but right now, I think you could tell your doctor next time you have a physical (which I assume will be sometime in the next several months or so), but don't stress about it, OK? Good luck - PJH