Host response and tumour biological behaviour in the two histological types of gastric carcinoma

T cell receptor Vbeta repertoire expression reflects gastric carcinoma progression

Analysis of TCR beta-chain complementarity-determining region size gives an indication of the T cell immune response. We examined CD4+ and CD8+ subgroups of T cells in the peripheral blood (PBL), benign gastric mucosa, and tumor (TIL) lymphocytes of 12 patients with primary gastric carcinomas of both intestinal and diffuse types. The average number of expanded clones in each compartment, expressed by the 24 families of the TCRVbeta repertoire, was analyzed according to tumor histological type, maximal invasive depth, and lymph node metastases. Fewer clones were expressed by the PBL in the cases with lymph node metastases than in those without (CD4+ P = 0.00017, CD8+ P = 0.016). Fewer CD8+ clones were expressed by the PBL in the cases with full thickness tumor infiltration than in those involving only the mucosa and submucosa (P = 0.05). The CD8+ TIL showed significantly fewer clones in the diffuse-type carcinoma than in the intestinal type (P = 0.046).

Epidemiology of intestinal and diffuse types of gastric carcinoma. A time-trend study in Finland with comparison between studies from high- and low-risk areas

The incidence of gastric cancer has declined markedly in Finland during the last 4 decades. To document the changes caused by that in the ratio of the intestinal type (IT) to the diffuse type (DT) of gastric carcinoma we compared the 367 cases diagnosed from southwestern Finland at the Department of Pathology, Turku University, from 1950-1959 and 1076 cases from 1980-1989. IT virtually disappeared in the male and female populations younger than 50 years, and in patients younger than 60 years, DT became more common than IT (P < 0.001). The transitional age, the time at which IT exceeds DT in frequency, shifted by 20 years to older age groups. In patients older than 60 years, IT remained the dominant type, but the ratio of IT to DT (IT:DT) decreased in men from 3.8 to 2.1 (P < 0.05) and in women from 4.4 to 2.1 (P < 0.001). No decrease in the frequency of DT could be demonstrated in the material studied. The disappearance of the male-dominant IT in the younger male population changed the male-to-female ratio of patients reported to the Finnish Cancer Registry. When the ratio IT:DT in Finland was compared with the ratios reported by the authors in data from other continents and by other investigators, regional variations in basal level of IT:DT emerged. This phenomenon seems to be based on the differing genetic susceptibility to DT of various races. The decrease of IT, seen in reports from regions with declining incidence of gastric carcinoma, seems to be connected to a diminished rate of severe chronic gastritis.

Association of macrophages detected with monoclonal antibody 25 F 9 with progression and pathobiological classification of gastric carcinoma

Using monoclonal antibody 25 F 9, which reacts with a determinant of mature macrophages, the inflammatory infiltrate of 66 gastric carcinomas was evaluated using a counting grid. The ratio tumor cells/macrophages was determined for every tumor. For a threshold value of 5, carcinomas with a better prognosis, such as the intestinal type according to Lauré, the expanding type according to Ming and the differentiated carcinomas according to the WHO had a significantly smaller relative content of 25 F 9-positive macrophages (a minimum of P less than 0.05) than the diffuse type, infiltrative type, and undifferentiated carcinomas. Furthermore, the relative macrophage content tended to increase with the stage of carcinomas spread (P less than 0.1). The results suggested that 25 F 9-positive macrophages in gastric carcinoma are of greater significance in tumor spread than in any defensive reaction against the tumor.