OBJECTIVETo evaluate the roles of folic acid and beta-carotene in the chemoprevention of gastric and other gastrointestinal (GI) cancers.

METHODSIn a randomized, double-blind, placebo-controlled trial, a total of 216 patients with atrophic gastritis were randomly assigned to one of the four groups: (1) folate (FA, 20 mg per day plus vitamin B(12) 1 mg, intramuscularly, per month for one year, then 20 mg two times a week plus 1 mg per three months for the next year); (2) natural beta-carotene (N-betaC, 30 mg per day for first year, then 30 mg two times a week for the next); (3) synthetic beta-carotene (S-betaC, administered as in N-betaC); and (4) placebo. Follow-ups continued from 1994 to 2001.

RESULTSA total of 7 new cases of gastrointestinal cancers were diagnosed with 3 stomach, 1 colon and 1 esophageal cancers occurring in the placebo group; 1 stomach cancer in both of the N-betaC and S-betaC groups, and no cancer occurring in FA group. In terms of GI cancers, there was a significant reduction in the FA group, compared with the placebo group (P = 0.04). A similar trend was observed in both N-betaC and S-betaC groups (P = 0.07 - 0.08). Taken together, the three intervention groups displayed a highly significant decrease in occurrence (P = 0.004, vs placebo), and a lower risk for GI cancers (OR = 0.12; 95% confidence interval, 0.03 - 0.51). For development of gastric cancer, any one of the three active-treated groups did not reach statistically significant reduction. The FA group showed obvious improvement of the gastric mucosal lesions with more patients displaying lesions reversed or stable atrophy and inflammation (P = 0.04), reversed intestinal metaplasia (P = 0.06) at the end of follow-up, and reversed displasia (P = 0.017) at 12 months. Two cases of false jaundice were found in beta-carotene groups with no influence on administration, and no side-effects were reported in FA group.

CONCLUSIONSThis trial revealed the interventional effect of folic acid on the development of GI cancers, a similar effect of beta-carotene was also detected. Also, folic acid may be of use to treat atrophic gastritis by preventing or reversing the precancerous lesions.

Adult ; Aged ; Anticarcinogenic Agents ; therapeutic use ; Double-Blind Method ; Female ; Folic Acid ; adverse effects ; therapeutic use ; Gastric Mucosa ; pathology ; Gastrointestinal Neoplasms ; prevention & control ; Humans ; Male ; Middle Aged ; Patient Compliance ; Stomach Neoplasms ; prevention & control ; beta Carotene ; therapeutic use

Curettage is the main treatment method for oral maxillofacial cystic lesions,but simple curettage may easily damage surrounding structures such as adjacent teeth and nerves,leading to incomplete removal of the cyst and large jaw defects.The curettage assisted by endoscopy can provide a good surgical field for the surgeons,can clearly identify the important anatomical structure during the operation and can remove the cyst wall tissue as much as possible,thereby reducing the damage and reducing the recurrence rate of the lesion.This article combines the characteristics of maxillofacial surgery with clinical treatment experience,summarizes relevant literature from both domestic and international sources,and engages in discussions with experts in order to provide reference for the clinical treatment of jaw cystic lesions with endo-scope assisted curettage.