In addition, Dr. Joseph C. Anderson of the University of Connecticut in Farmington and Dr. Zvi A. Alpern of Stony Brook University in New York found smoking may increase the risk of pancreatic cancer precursor lesions, particularly in patients with a strong family history of the disease.

In a large cross-sectional study, Anderson and Alpern analyzed data of 2,707 patients who underwent colonoscopy from 1999 to 2006. Data collected included age, height, weight, family history of colon cancer, medication use, surgery, exercise, diet and smoking history.

Patients were divided into three smoking groups: heavy exposure, low exposure and no exposure. The heavy exposure group was separated into two sections: those who smoked 30 pack years or less and those who smoked more than 30 pack years. "Pack years" are determined by multiplying the packs of cigarettes smoked per day by the number of years smoked.

The study found that women who smoked less than 30 pack years were almost twice as likely to develop significant colorectal neoplasia compared to women who were not exposed to cigarette smoke.

The findings were presented at the 73rd annual American College of Gastroenterology scientific meeting in Orlando, Fla.