Malignant tumours of the stomach.

The commonest malignant tumour of the stomach is gastric carcinoma. Although the incidence of this neoplasm has declined worldwide, it still ranks fifth to seventh as a cause of cancer-related deaths in the West where the overall 5-year survival from the disease remains poor and averages 5-10%. The decline in the incidence of gastric cancer during the past 4 decades is largely confined to antral tumours of the intestinal type. During this period an absolute increase in the prevalence of cancers of the upper third of the stomach has been observed. Japan is the only country where the mortality has declined proportionately more than the decreased incidence of the disease. This is attributed to a successful screening programme for the detection of early gastric cancer, better staging and probably more aggressive surgical treatment with an extended lymphadenectomy. The latter remains unproven and is currently being evaluated prospectively in a Medical Research Council trial being conducted in the United Kingdom. Surgical excision remains the mainstay of therapy. To date there has been no firm evidence that peri-operative radiotherapy imparts any therapeutic advantage. Overall survival is not improved by adjuvant combination chemotherapy although the early results of a modified FAM regimen with cisplatin are encouraging in terms of response rates. Gastric carcinoids most frequently arise in patients with pernicious anaemia due to the prolonged hypergastrinaemia. Although they can metastasize, their prognosis is good and resection is indicated even in the presence of deposits. Gastric lymphoma accounts for 0.5-3% of gastric malignancies and is the prototype of malignant lymphomas arising from mucosa associated lymphoid tissue (MALT) present in the gastrointestinal tract and other organs. The majority of these tumours are B-cell lymphomas which are slow growing and tend to remain localized until late in the course of the disease. The various accepted histological classifications are difficult to apply to MALT lymphomas which are nowadays regarded as a distinct entity the prognosis of which is determined more by stage than histological type. They frequently cause diagnostic problems because of their indolent growth characteristics and their close simulation to benign lymphoid infiltrates. In the past, the term "pseudolymphoma" was applied to those extranodal proliferations of lymphoid tissue the nature of which was uncertain. This problem has been resolved by the advent of immunocytochemical and molecular biological techniques such that it is now always possible to distinguish a reactive from a neoplastic lymphoid infiltrate.(ABSTRACT TRUNCATED AT 400 WORDS)