Study Links Nicotine, Breast Cancer Finding could be a blow to nicotine patches, gum By Kevin Spak, Newser Staff Posted Aug 24, 2010 3:21 PM CDT 6 comments Comments Smoking can damage more than your lungs. (Shutterstock) (Newser) – Smoking could hurt more than just your lungs. A new study suggests nicotine causes breast cancer tumors to grow. The finding is especially significant, the Daily Mail explains, because though cigarettes are known to contain at least 60 cancer-causing substances, this is the first time nicotine has been implicated as one of them. That means the study could be very bad news for the makers of nicotine gum, patches, and other products designed to help you quit. Researchers cautioned, however, that their study had a small sample size, comprising only a few hundred Asian patients, and that more research was needed.