Risk factors of stomach cancer

ENVIRONMENTAL RISK FACTORS

Environmental factors have an important role in the etiology of gastric cancer and that exposure to risk factors occurs early in life.

1.Helicobacter pylori —   H. pylori is classified by WHO as  definite carcinogen. Test and treat H pylori

 Intestinal-type gastric carcinoma is believed to evolve as a progression from atrophy to metaplasia, to dysplasia, and then to carcinoma. The most common cause of gastritis is H. pylori

2. Diet

Salt and salt-preserved foods — Substantial evidence   suggests that the risk of gastric cancer increases with a high intake of salt and various traditional salt-preserved foods, such as salted fish, cured meat, and salted vegetables

The declining incidence of gastric cancer worldwide over the last 50 years has been attributed, at least in part, to the spread of refrigeration,the use of which would inversely correlate with salting and other salt-based methods of preservation, such as curing and smoking, and with the overall volume of salt in the diet.

Nitroso compounds — Humans are exposed to N-nitroso compounds (compounds containing an -NO group) from diet, tobacco smoke, and other environmental sources, as well as from endogenous synthesis, which contributes to 40 to 75 percent of total exposure

N-nitroso compounds are generated after consumption of nitrates, which are natural components of foods like vegetables and potatoes and are used as a food additive in some cheeses and cured meats.

●Diets that are high in fried food, processed meat, fish, and alcohol (and low in vegetables, fruits, milk, and VITAMIN A    have been associated with an increased risk of gastric carcinoma in several epidemiologic studies

Low folate levels —  

Obesity — Excess body weight is associated with an increased risk of gastric cancer 

Smoking — Several studies have examined the relationship between tobacco smoking and gastric cancer. In a study approximately 18 percent of gastric cancer cases were attributed to smoking.

Occupational exposures — There is some evidence that occupations in coal and tin mining, metal processing (particularly steel and iron), and rubber manufacturing industries lead to an increased risk of gastric cancer.

Influence of salt and intake of salted foods — As noted above, there is a link between intake of salt and highly salted foods and gastric cancer risk; high salt intake damages stomach mucosa and increases the susceptibility to carcinogenesis.

Socioeconomic status — The risk of distal gastric cancer is increased by approximately twofold in populations with low socioeconomic status

 By contrast, proximal gastric cancers have been associated with higher socioeconomic class

Gastric surgery — There is an increased risk of gastric cancer after gastric surgery, with both the risk and the interval between initial gastric surgery  ●The risk also increases with longer duration of follow-up after gastric surgery

Possible protective factors

Weight reduction and regular exercise

Fruits, vegetables, and fiber — Consumption of fruits and vegetables (particularly fruit) is probably protective against gastric cancer

The protection afforded by vegetables and fruits is most likely related to their vitamin C content, which is thought to reduce the formation of carcinogenic N-nitroso compounds inside the stomach. Cooked vegetables do not show the same protective effect as uncooked vegetables . Properly washed Salad is thus better 

Dietary fiber may reduce the risk of gastric cancer.