Spontaneous and complete disappearance of diffuse large B-cell lymphoma (DLBL) of the stomach is extremely rare. Although regression of gastric DLBL after eradication of Helicobacter pylori has recently been reported, we present two consecutive cases of stage I DLBL of the stomach which disappeared after only nonspecific therapy, including histamine 2-receptor antagonist (H2RA); both cases were documented histologically and endoscopically. Both patients were positive for H. pylori, and later received H. pylori eradication therapy. The disease has not recurred after 11 and 6 months, respectively. Our cases suggest that the option of combination therapy with H2RA either with or followed by H. pylori eradication is appropriate for consideration as an initial approach in standard therapy for stage I diffuse large B-cell gastric lymphoma.

BACKGROUND:Syndecan-1 is known to play a role as a cell adhesion molecule, similar to E-cadherin, and is associated with the maintenance of epithelial morphology. The purpose of this study was to elucidate the role and alterations of syndecan-1 expression in comparison with those of E-cadherin in different cellular phenotypes of differentiated-type gastric cancers (DGCs).METHODS:A total of 80 DGCs at an early stage, and their adjacent mucosa, were evaluated by both immunohistochemistry and in situ hybridization. Syndecan-1 and E-cadherin were assessed by immunohistochemical staining with an anti-syndecan-1 and an anti-E-cadherin antibody, respectively. Based on immunohistochemistry, DGCs and their surrounding mucosa were divided into four types: gastric type (G-type), ordinary type (O-type), complete-intestinal type (CI-type), and null type.RESULTS:The expression sites of syndecan-1 mRNA mostly coincided with those of syndecan-1 protein. Syndecan-1 expression was significantly lower in G-type cancers (30%) than in O- (81%) and CI-type cancers (92%) ( P = 0.0001 and P = 0.004, respectively), but E-cadherin did not show this result. In addition, syndecan-1 expression was significantly reduced in DGCs comprised partly of poorly differentiated adenocarcinoma or signet-ring cell carcinoma, compared to DGCs demonstrating papillary and/or tubular adenocarcinoma ( P = 0.02). G-type intestinal metaplasia (IM) surrounding the tumors was observed in 21% of G-type cancers, in 0% of O-, and in 10% of CI-type cancers ( P = 0.01; G-type vs O-type). Reduction of syndecan-1 expression was significant in G-type IM (25%) compared to non-G-type IM (75%; P = 0.02).CONCLUSIONS:Syndecan-1 plays a role in the growth of G-type cancers at an early stage compared with E-cadherin changes, and the reduction of syndecan-1 expression in IM surrounding the tumors may influence the growth of G-type cancer.

We report two patients with Type 4 gastric cancers having multiple lymph node metastasis and carcinomatosa which responded well to TS-1. After administration of TS-1 orally for two courses, both patients showed improved extension of the gastric wall and almost complete reduction of metastatic lymph nodes. In case 2, colonic stenosis due to peritonum carcinomatosa disappeared after chemotherapy with TS-1. Total gastrectomy was performed in both patients in accordance with their wishes. It was confirmed histopathologically that TS-1 was effective against the primary sites and lymph node metastasis. Both patients are well without recurrence and continue taking TS-1.

Primary cultured mouse hepatic cells become senescent within a short period, although rare cells form colonies from which continuously proliferating cell lines can be established. In contrast, hepatic tumor (HT) cells show little senescence and higher colony‐forming capacity. To assess this difference, we investigated p16Ink4a/p19Arf/p53/p21Waf1/Cip1 expression in primary normal and HT cells, together with cell lines established from both. In primary normal cells, p16Ink4a/p19Arf were expressed only in association with senescence and disappeared at later stages of colony formation. In contrast, primary HT cells showed sustained p16Ink4a/p19Arf expression from the beginning. No p16Ink4a/p19Arf alterations, such as deletion, mutations, or hypermethylation, were detected in the primary HT cells, although most cell lines derived from either normal or HT cell colonies lost p16Ink4a or p19Arf expression owing to hypermethylation or homozygous deletion of p16Ink4a/p19Arf. On the other hand, primary normal and HT cells and most cell lines showed constitutively elevated expression of p53/p21Waf1/Cip1, with a further increment after ultraviolet ir‐radiation, indicating a functionally normal p53 pathway. These results indicate that primary HT cells are resistant to senescence despite retaining p16Ink4a/p19Arf/p53/p21Waf1/Cip1 expression and that loss of p16Ink4a/p19Arf function is associated only with establishment of the cell lines. © 2001 Wiley‐Liss, Inc.