Chemical peels...won't cause any cancer . Chemical peels are usually made  up of fruit acids like glycolic(sugarcane),citric acid (citrus fruits)..lactic acid..used for facial rejuvination. Chemical peels are used for different conditions like acne(pimples), black spots(hyperpigmentation),solar melanosis(tanning)..etc So if its used on right problem,on right spots on right condition with properly trained doctors(Dermatologist).. there is no harm in getting chemical peels done.