Well, nothing "gives" you cancer. Substances can only increase your odds of contracting cancer. Studies have shown that nonsmokers who chew tobacco or use other smokeless tobacco products have a higher incidence of mouth, tongue and throat cancers than those who do not. I doubt if licking the tobacco leaves to make a blunt represents a significant elevation in the risk for cancer, but there is almost certainly at least some increased risk. I wouldn't worry about it, personally. You probably have a higher risk from smoking the blunts, actually.