Kazuya Endo

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.

EXPRESSION OF THE METASTASIS-ASSOCIATED MTA1 PROTEIN AND ITS RELATIONSHIP TO DEACETYLATION OF THE HISTONE H4 IN ESOPHAGEAL SQUAMOUS CELL CARCINOMAS

Metastasis‐associated protein MTA1 and histone deacetylase form a protein complex with histone deacetylase activity that plays an important role in histone deacetylation, alteration of chromatin structure and transcriptional control. The precise role of the MTA1 protein in the malignant progression of human cancers remains unknown, however, especially its overexpression and relationship with histone acetylation/deacetylation in experimental and clinical tumors. The expression levels of MTA1 protein and the acetylation levels of histone H4 were examined in 70 cases of surgically resected esophageal squamous cell carcinomas, using immunohistochemistry. The intensities of immunostaining of MTA1 protein and acetylated histone H4 in carcinoma tissues (Ca) were compared to normal epithelium (N) contained in the same section. Thirty of 70 cases (42.9%) displayed overexpression of MTA1 protein (N < Ca). Cancers overexpressing MTA1 protein invaded deeper into the esophageal wall (p < 0.005) and showed significantly higher degrees of lymph node metastasis (p < 0.01), higher pathological stage, more lymphatic involvement and poorer prognosis (p < 0.05) than the remaining cases. The acetylation levels of histone H4 inversely correlated to the depth of cancer invasion and pathological stage (p < 0.05), and the patients with higher level of histone H4 acetylation had a better prognosis (p < 0.05). Furthermore, immunostaining patterns of MTA1 and acetylated histone H4 were inversely correlated (p < 0.001), demonstrating the relationship of deacetylation of histone H4 in MTA1‐overexpressing carcinomas. In conclusion, the data suggest that the overexpression of MTA1 protein and acetylation level of histone H4 protein, both of which are closely related, might be useful predictors of malignant potential of esophageal squamous cell carcinomas. Thus, strategies involving inhibition of MTA1 function as well as inhibition of histone deacetylation could be novel approaches for the treatment of esophageal squamous cell carcinomas.

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.

Expression of glutathione s‐transferasepi and sensitivity of human gastric cancer cells to cisplatin

Background. The authors examined the correlation between the expression of glutathione S‐transferase‐pi (GSTπ) and the sensitivity of gastric cancer to anticancer agents.

Suppressed MKP-1 Is an Independent Predictor of Outcome in Patients with Hepatocellular Carcinoma

Objective: An increase in the activity of mitogen-activated protein kinases (MAPKs) has been correlated with a more malignant phenotype in several tumor models in vivo. This study was designed to clarify the expression of MKP-1 in surgically resected hepatocellular carcinoma (HCC). Methods: We reviewed the cases of 77 patients who had undergone initial liver resection for HCC without preoperative treatment. Immunohistochemical analysis of MKP-1 was performed on paraffin-embedded tissues. The correlation between MKP-1 expression and clinical outcome was investigated. Results: Tumor cells were immunohistochemically stained for MKP-1 expression, and the same levels as in normal hepatocytes were detected in 66 (85%) of 77 HCC patients, being decreased in 11 (15%) HCCs. Decreased MKP-1 expression significantly correlated with serum α-fetoprotein levels and tumor size (p < 0.05). The disease-free survival rates in MKP-1-negative and -positive patients were 0 and 31.0% at 5 years, respectively (p < 0.01). The survival rates after a surgical resection in MKP-1-negative and -positive patients were 18.2 and 65.5% at 5 years, respectively (p < 0.01). Conclusions: The MKP-1 expression in HCC was an independent prognostic factor for outcome in HCC patients. In the future, it will be useful to explore whether the phosphatase expression might account for the response to HCC treatments targeting at MAPK activation.

Gastric adenosquamous carcinoma producing granulocyte-colony stimulating factor

We report a case of adenosquamous carcinoma of the stomach that produced granulocyte-colony stimulating factor (G-CSF). The patient, who had an admission diagnosis of advanced gastric cancer, had marked leukocytosis without evidence of infection. After leukemia and metastatic leukemoid reaction were excluded by bone marrow examination, a G-CSF-producing cancer was suspected as the cause of the abnormally elevated serum G-CSF level. The resected stomach tumor was histologically diagnosed as adenosquamous carcinoma; positive expression of G-CSF by tumor cells was shown with immunohistochemical detection, which confirmed the preoperative diagnosis. Recurrent disease in the liver and lymph nodes, accompanied by leukocytosis and re-elevation of serum G-CSF, developed just 3 months after the curative gastrectomy and adjuvant chemotherapy. All of the recurrent disease was resected, restoring normal levels of serum G-CSF. The patient survived for almost 2 years after the initial surgery with extensive chemotherapy, including weekly treatment with paclitaxel, before finally succumbing to liver failure secondary to extensive liver metastasis.

Clinical efficacy of S-1 combined with cisplatin for advanced gastric cancer

Several chemotherapy regimens used against advanced gastric cancer have been studied extensively over the decades in an attempt to further improve the prognosis of patients. To date, no standard chemotherapeutic regimens have been established worldwide. S-1 (TS-1®), a combination of ftorafur and two modulators, gimestat (CDHP) and oxonic acid, in a molar ratio of 1 : 0.4 : 1, has been widely used in Japan for the treatment of advanced gastric cancer, and much attention has been paid to attempts to increase its antitumor effect by combining it with other chemotherapeutic drugs. We treated 12 patients with advanced gastric cancer with 80 mg/m2 of S-1 for 21 days and 60 mg/m2 of cisplatin (CDDP) on day 8 every 5 weeks. The treatment was continued until disease progression, unacceptable toxicity, or the patients refusal. Eight out of 12 evaluable patients achieved a partial response (PR), with a response rate of 66.7%. The incidence of grade 3 or 4 adverse effects, including myelosuppression and gastrointestinal toxicities, was 16.6%. None of the patients treated with this regimen died of adverse effects and none required hospitalization for the toxicity. We conclude that the combination of S-1 and CDDP seems to have a high therapeutic index, enhancing the antitumor effect of S-1 while maintaining modest adverse effects, thus suggesting the possible use of this combination based at the outpatient clinic (apart from a short stay in hospital during the infusion of CDDP with hydration). Further study with a large number of patients may be needed to confirm the combination of S-1 and CDDP to be an appropriate first-line chemotherapy for gastric cancer.

Prognostic significance of tumor markers in peritoneal lavage in advanced gastric cancer.

Objective: Predicting peritoneal dissemination of cancer is very difficult whatever method of examination is used. Recently, a cytological examination of peritoneal lavage has been shown to be a feasible measure to predict an early state of peritoneal seeding. The predictive value of the levels of tumor markers in peritoneal lavage for peritoneal metastasis from gastric carcinoma was thus studied. Methods: In 229 patients gastric cancer tumor markers, CEA, CA 125, and CA 19-9, in peritoneal lavage were intraoperatively evaluated using a chemiluminescent enzyme immunoassay. Results: CEA in peritoneal lavage at a cutoff level of 0.5 ng/ml showed overall a higher sensitivity of 75.8% at a specificity of 90.8% for a diagnosis of peritoneal dissemination including cytologically positive peritoneal lavage [CY(+)] than CA 125 or CA 19-9 in peritoneal lavage. The CEA level in peritoneal lavage as well as both serosal invasion and the CA 125 level in peritoneal lavage were significant factors for the prediction of peritoneal dissemination including CY(+) with a relative risk of 6.6, 14.1 and 9.4. In patients undergoing curative operations, the recurrence rate for peritoneal dissemination and liver metastasis in cases with CEA levels in peritoneal lavage of ≧0.5 ng/ml was significantly higher than that in cases with CEA levels of <0.5 ng/ml (p < 0.0001, p < 0.002). Conclusions: These finding suggest that the CEA level in peritoneal lavage is thus considered to be a predictor of peritoneal dissemination including CY(+).

Impact of perioperative peripheral blood values on postoperative complications after esophageal surgery

PurposePrediction of the postoperative course of esophagectomy is an important part of the strict perioperative management of patients undergoing surgery for esophageal cancer.MethodsTo evaluate their clinical importance, peripheral blood values, including white blood cell count (WBC), lymphocyte count, and the levels of total protein, transferrin, factor XIII, D-dimer, fibrin, and fibrinogen degradation products (FDP) were measured before and after esophagectomy for esophageal cancer in 24 patients.ResultsThe preoperative WBC and the pre- and postoperative lymphocyte count were decreased remarkably in patients who received preoperative chemoradiotherapy. The values of perioperative serum transferrin were significantly lower in patients with postoperative pneumonia than in those without. The activity of plasma factor XIII was suppressed on postoperative day (POD) 7 in patients with pneumonia and on POD 14 in patients with leakage.ConclusionsThese results suggest that patients who receive preoperative chemoradiotherapy are potentially immunosuppressed, the preoperative serum transferrin level is a possible predictive marker of postoperative pneumonia, and suppression of factor XIII activity is related to anastomotic insufficiency.