Does chewing gum and smoking at the same time increase your risk of gum cancer

Does chewing gum and smoking at the same time increase your risk …?

http://www.chacha.com/question/does-chewing-gum-and-smoking-at-the-same-time-increase-your-risk-of-gum-cancer

I am not finding any correlation behind chewing gum and smoking at the same time increasing your chances of getting gum cancer.