Gastric precancerous changes: carcinogenesis, clinical behaviour immunophenotype study and surveillance.

Gastric cancer (GC) is the second most common cause of cancer-related death worldwide. Two-thirds of the GC patients are diagnosed in advanced stages, when surgery can only be a palliative. When the diagnosis is made at an early stage, the surgical treatment results in 10 years survival rates are higher than 85%. From the critical evaluation of the literature data we can affirm that there are some obstacles to an exclusive acceptance of the idea that the relation of Helicobacter pylori (H. pylori) infection with noninvasive (formerly dysplasia) or invasive neoplastic modifications solely develop by means of chronic gastritis with its atrophic evolution and achlorhydria. Intestinal metaplasia as a precursor of GC has been overemphasized and doubts persist about the real necessity to operate histologically a subdivision into subtypes. The extent of the metaplastic process is probably more important that the metaplastic subtype. The evaluation of the clinical behaviour shows how low grade noninvasive neoplasia is associated with or progressed to GC in about 9% of cases, while high grade noninvasive neoplasia is associated with or progressed to GC in about 75% of cases, thus proving to be a real histological marker of GC. The subdivision of the cases according to the TNM classification demonstrates that, in most of the cases, early GC is present (43/45: 95.5%). An appropriate endoscopy follow-up with biopsies according to well defined criteria increases the likelihood of invasive neoplasia being detected in its early stage with a better postsurgical prognosis. Noninvasive neoplasia is characterized by severe alterations of the immunophenotype profile in association with a high proliferation index and frequent p53 mutations. The choice to address the patients to surgical intervention could be made not only on the basis of histochemical techniques, but also with the help of immunohistochemical evaluations.