Yuji Ichiyoshi

Clinical significance of occult micrometastasis in lymph nodes from patients with early gastric cancer who died of recurrence

BACKGROUND Even after curative resection of an early gastric cancer, some patients die of a recurrence. It is our view that patients with early gastric cancer who died of their disease had occult micrometastases in perigastric lymph nodes at the time of the original diagnosis. In an attempt to identify these micrometastases, lymph nodes dissected from early gastric cancer lesions were stained after operation with monoclonal antibody against cytokeratin, an essential constituent of the cytoskeleton of epithelial cells. METHODS The 420 dissected lymph nodes from 34 patients with node-negative early gastric cancer who died of a recurrence were examined for the presence of tumor cells. We used immunocytochemical techniques and an antiserum to epithelial membrane antigen. The monoclonal antibody CAM 5.2 recognizes cytokeratin polypeptides (human cytokeratin numbers 8 and 18) commonly present in epithelial cells. Clinicopathologic characteristics and prognosis were determined for patients with cytokeratin-positive cells in the lymph nodes. RESULTS. Of 420 lymph nodes, 15 (3.6%) nodes and 23.5% (8 of 34) of the patients presented with cytokeratin-positive cells at the time of primary operation. The presence of cytokeratin positivity was not related to various clinicopathologic factors. The histologic stage of eight cytokeratin-positive cases was upstaged by the group of cytokeratin-positive lymph nodes from stage I to three of stage II, four of stage III, and one of stage IV, hematogenous recurrences were common, and the prognosis was poorer. CONCLUSIONS Immunohistochemical techniques aid in identifying micrometastatic disease in lymph nodes missed in routine hematoxylin-eosin staining. Cytokeratin staining of the dissected lymph nodes is recommended to precisely determine tumor stage and prognosis for patients with early gastric cancer.

Vascular endothelial growth factor expression in non-small-cell lung cancer: prognostic significance in squamous cell carcinoma.

BACKGROUND Recently, some studies have focused on the tumor angiogenesis and its prognostic value. We studied the expression of vascular endothelial growth factor, microvessel counts, and serum concentrations of vascular endothelial growth factor to investigate their association with clinicopathologic factors and prognosis in non-small-cell lung cancer. METHODS The expression of vascular endothelial growth factor was determined by an immunohistochemical analysis from 91 paraffin specimens of completely resected non-small-cell lung cancers using anti-growth factor polyclonal antibody. Microvessel staining was performed by immunohistochemical analysis with anti-factor VIII-related antigen polyclonal antibody. Measurement of the serum concentrations of vascular endothelial growth factor used the sandwich enzyme-linked immunosorbent assay technique. RESULTS Expression of vascular endothelial growth factor was detected in 48 of the 91 tumors. The positive ratio was significantly higher in patients with adenocarcinoma than in those with squamous cell carcinoma. The microvessel counts were significantly higher in the patients with nodal metastasis than in those without nodal metastasis. The serum concentrations of vascular endothelial growth factor were also significantly higher in the patients with T3-4 disease than in those with T1-2 disease. The microvessel counts were closely associated with expression of vascular endothelial growth factor. The prognosis of patients with a positive growth factor ratio was significantly worse than that of the patients with a negative ratio (p = 0.002), especially in squamous cell carcinoma. According to a multivariate analysis, only nodal status and expression of vascular endothelial growth factor were found to be independent prognostic factors. CONCLUSIONS The expression of vascular endothelial growth factor was one of the most important prognostic factors in completely resected non-small-cell lung cancer, especially in squamous cell carcinoma.

Microvessel quantification and its possible relation with liver metastasis in colorectal cancer

Several studies have proven the usefulness of microvessel quantification as a prognostic factor for patients with various malignant tumors. The aim of this paper was to clarify the relationship between microvessel density (MVD) as a parameter of tumor angiogenesis and liver metastasis in colorectal cancer.

Prognostic value of the immunohistochemical detection of p16INK4 expression in nonsmall cell lung carcinoma

The product of the p16INK4/CDKN2/MTS1 (p16) controls the transition from the G1 phase to the S‐phase in the cell cycle by inhibiting the phosphorylation of the retinoblastoma gene product. A lack of p16 expression has been reported in various cancer cell lines and tumors; however, there have been only a few reports on the prognostic significance of p16 alteration. The authors studied p16 expression in nonsmall cell lung carcinoma (NSCLC) and also examined its correlation with clinicopathologic features and prognosis.

Age-related characteristics of gastric carcinoma in young and elderly patients

The clinicopathologic features of young and elderly patients with gastric carcinoma have been analyzed.

Recurrences and related characteristics of gastric cancer.

We analysed data on 1117 patients with gastric cancer who were treated by curative resection. Attention was focused on invasion and a recurrence of the cancer. Based on a univariate analysis, death following a recurrence and prognosis were related to age of the patients, size of the tumour, tumour location, tumour tissue differentiation, growth pattern, depth of invasion, lymphatic and vascular invasion and lymph node metastasis. In proportion to the growth potential, determined by the level of proliferating cell nuclear antigen (PCNA) labelling, the death related to a recurrence was increased and the prognosis was poorer. Multivariate analysis showed that the three factors of serosal invasion, PCNA labelling index and lymph node dissection were independent prognostic factors. When sites of recurrence were analysed regarding each depth of invasion, haematogenous recurrence, in particular in the liver, occurred even in cases of an early invasion and many types of recurrences, including peritoneal recurrence, were noted in patients with an advanced state of invasion.

Cytokeratin-positive cells in bone marrow for identifying distant micrometastasis of gastric cancer.

Direct evidence of tumour seeding in distant organs at the time of surgery for gastric cancer is not available. An immunocytochemical assay for epithelial cytokeratin protein may fill this gap since it is a feature of epithelial cells that would not normally be present in bone marrow. The bone marrow of 46 patients with primary gastric cancer was examined for tumour cells, using immunocytochemical techniques and antibody reacting with cytokeratin, a component of the intracytoplasmic network of intermediate filaments. The monoclonal antibody CK2 recognises a single cytokeratin polypeptide (human cytokeratin no. 18) commonly present in epithelial cells. The expression of tumour-suppressor genes p53 and RB for the primary lesion was also determined using the monoclonal antibodies PAb 1801 and 3H9 respectively, and the proliferating activity was determined by the Ki-67 antigen labelling index for MIB-1 antibody staining. Of these 46 patients, 15 (32.6%) presented with cytokeratin-positive cells at the time of primary surgery. The positive findings were related to the undifferentiated tissue type and to the prominent depth of invasion, but not to other clinicopathological factors. In 2 of 15 (13.3%) patients, the depth of invasion was limited to the mucosa. The metastatic potential to bone marrow did not relate to expressions of p53 and RB genes, or to the proliferating activity of MIB-1 staining for the primary lesion of gastric cancer. As tumour cells in bone marrow are indicative of the general disseminative capability of an individual tumour, this technique may be useful for identifying patients at high risk of metastasis from a gastric tumour.

Intratumoral neovascularization and growth pattern in early gastric carcinoma

The growth pattern of early gastric carcinoma, based on a volumetric analysis, reflects biologic characteristics of the tumor. The authors investigated the microvessel density (MVD), expression of vascular endothelial growth factor (VEGF), and growth patterns in early gastric carcinoma.

Expression of multidrug‐resistance‐associated protein (MRP) and chemosensitivity in human gastric cancer

Evidence has accumulated that, in addition to the MDRI gene‐coded P‐glycoprotein (Pgp), multidrug resistance‐associated protein (MRP) also mediates the multidrug resistance (MDR) of various human tumors. In the case of gastric cancer, there is little or no involvement of P‐glycoprotein, and the mechanisms of MDR remain to be understood. To search for a possible relationship between expression of MRP and sensitivity to anti‐cancer agents in gastric cancer, 4 gastric cancer cell lines, 43 human gastric carcinomas and 17 adjacent normal gastric tissue samples were analyzed. Expression of MRP mRNA was evaluated using reverse transcription PCR (RT‐PCR) and Southern hybridization. Sensitivity of the test samples to the anti‐cancer drugs cisplatin (CDDP), doxorubicin (DXR) and etoposide (VP‐16) was examined using the MTT{3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl [2H]‐tetrazolium bromide} assay. Immunohistochemical staining with the use of the MRP antibody (MRPrI) was done to confirm the findings regarding the expression of mRNA levels. The MRP expression evaluated with RT‐PCR and Southern hybridization as well as with immunohistochemical staining revealed that 23 of 43 gastric‐cancer tissues (53.5%), 15 of 17 normal gastric tissues (88%) and 3 of 4 gastric‐cancer cell lines (75%) were positive. The MTT assay showed that DXR was significantly more sensitive (p < 0.01) in gastric carcinoma tissues lacking MRP expression than in those with positive expression. The same tendency was seen with the other agents used. Of the cell lines, one which showed no MRP expression also had a higher sensitivity to CDDP, DXR and VP‐16 than the other positive cases. These results show that MRP expression is involved in MDR of human gastric cancer and is inversely related to the chemosensitivity of tumor cells against some anticancer drugs.

Multidrug resistance-associated protein expression in clinical gastric carcinoma

We examined the relationship between the expression of a multidrug resistance‐associated protein (MRP) and the biologic factors regarding invasion and metastasis of human gastric cancer.