**6. Perspectives**

Based on the observations in Vietnam for colorectal cancer, the distribution of this disease and its causality as well as risk factors were identified. With these findings, some points can be induced:

Colorectal cancer is related to unrecognized heat-generated carcinogens in our foods: we found that tobacco smoking, barbecued meats, bread, and biscuits intake increase the risk of the disease. Tobacco heated at 950oC and smoking carcinogens can generate as much as 3800 types of chemicals [56, 57, 61]. These findings were partly published [24]. Chemical is an independent factor inducing cancer, which was successfully performed and reported for the first time in 1967 by Dr. Sugimura [60, 69]. Our epidemiological observations in humans consisted of these numbers from previous studies.

Control of cooking temperature in both family's kitchen as well as public restaurants in humans' daily life should be a significant consideration to prevent colorectal cancer in particular and all cancer sites in general.

In our study, although alcoholic beverages play an integral role in humans' diets worldwide, alcoholic consumption would be categorized as a promoting factor of colorectal cancer development. Because of the organic solution of chemical carcinogens, similar to tobacco smoking, barbecued meats, bread, and biscuits are promoting colorectal cancer in our body.

• Host factors committed to developing colorectal cancer included blood types A and AB, CYP1A1 genotypes A/G and G/G, family history of cancer, body mass index, history of colorectal pain, and inflammation.
