I Miyazaki

Expression of C-erbB-2 oncoprotein in gastric carcinoma. Immunoreactivity for C-erbB-2 protein is an independent indicator of poor short-term prognosis in patients with gastric carcinoma

Correlations of c‐erbB‐2 protein expression with clinical outcomes of gastric carcinomas were studied in 189 gastric carcinomas. There were 23 (12.2%) carcinomas with evidence of c‐erbB‐2 protein in which the reaction was localized to the cell membrane. There was no significant association between c‐erbB‐2 staining and the macroscopic or histologic type of the carcinomas. c‐erbB‐2‐stained tumors were more likely to be associated with serosal invasion, nodal involvement, and peritoneal metastasis, than c‐erbB‐2‐unstained ones. In addition, c‐erbB‐2 was stained in none of early gastric carcinomas. The 5‐year survival rates of the c‐erbB‐2 protein‐positive and the protein‐negative group were 11% and 50%, respectively. When the c‐erbB‐2 tissue status and seven clinicopathologic variables as conventional prognostic factors were entered simultaneously into the Cox regression model, serosal invasion, hepatic metastasis, peritoneal metastasis, nodal status, and c‐erbB‐2 tissue status emerged as independent prognostic variables. The results suggested that c‐erbB‐2 protein expression might be enhanced in advanced stages during the progression of gastric carcinoma. In this particular group of patients, immunoreactivity for c‐erbB‐2 protein is an indicator of poor short‐term prognosis.

Growth fractions in gastric carcinomas determined with monoclonal antibody Ki‐67

The growth fractions of 101 gastric carcinomas were determined in situ by immunostaining with the monoclonal antibody Ki‐67 and the results correlated with the histopathologic findings, bromodeoxyuridine (BrdU) labeling index, and DNA ploidy pattern. DNA ploidy patterns were determined by flow cytometric analysis. The Ki‐67 labeling rates are rated from 4.6% to 82% (mean, 22%). A significant correlation was found between Ki‐67 labeling rates and BrdU labeling indices. Sixty‐seven percent of tumors with lymph node metastases showed Ki‐67 labeling rates of greater than 22%, whereas 33% of tumors without lymph node metastases showed Ki‐67 labeling rates of less than 22%. There was a significant correlation between these two groups. Tumors with vessel invasion more often have higher Ki‐67 labeling rates than those without vessel invasion. By the DNA ploidy classification, the mean Ki‐67 labeling rates of aneuploid tumors was significantly higher than that of diploid tumors. This method yielded similar results to those obtained by BrdU labeling and flow cytometric study. The measurement of Ki‐67 labeling rates may be useful to decide the therapeutic modalities.

Interrelationship between Transforming Growth Factor-α and Epidermal Growth Factor Receptor in Advanced Gastric Cancer

An immunohistochemical study for transforming growth factor-alpha (TGF alpha) and epidermal growth factor receptor (EGFR) was made with 167 primary tumors of advanced gastric cancer to demonstrate the potential existence of autocrine mechanism. TGF alpha stained positively in 87 (52%), and EGFR in 68 (41%) of the tumors. The authors classified the tumors into the following three groups: group 1 with neither TGF alpha nor EGFR staining positively (63 tumors); group 2 with either TGF alpha or EGFR staining positively (53 tumors); group 3 with both TGF alpha and EGFR staining positively (51 tumors). The incidence rates of macroscopically infiltrative tumors and large tumor measuring 6 cm or more in diameter were significantly higher for group 3 than for groups 1 and 2. The patients of group 3 had the poorest prognosis, with a 5-year survival rate of only 12%, while the 5-year survival rates were 45 and 36% for groups 1 and 2. There was a significant difference in survival between the patients of group 1 and those of group 3. Bromodeoxyuridine labeling indices were significantly higher in the tumors belonging to group 3 (median 15.8%) than in those of group 1 (median 10.8%). The results suggest that the autocrine mechanism between TGF alpha and EGFR may play an important role in the progression of gastric cancer, and that when such a mechanism becomes operative, prognosis may be poor.

Prognostic value of S-phase fraction and DNA ploidy studied with in vivo administration of bromodeoxyuridine on human gastric cancers

The authors studied the prognostic values of DNA ploidy pattern and proliferative activity with in vivo administration of bromodeoxyuridine in human gastric cancers. Fresh specimens surgically removed from 117 patients with gastric cancer were investigated by flow cytometric study using a monoclonal antibody to bromodeoxyuridine. DNA ploidy patterns were classified into four types according to the bivariate BrdUrd/DNA distribution: D1, tumors with single diploid population; D2, tumors which showed mosaic of diploid and aneuploid population; A1, tumors with single aneuploid population; and A2, several aneuploid populations without diploid population. The numbers of cases of each ploidy pattern were as follows: D1, 36 cases (30.8%); D2, 38 cases (32.5%); A1, 15 cases (12.8%); and A2, 27 cases (23.1%). DNA ploidy pattern and S‐phase fraction (SPF) showed no relation with clinicopathologic findings, except for type A2. In type A2, lymph node metastasis and lymphatic vessel invasion were observed more often than type D1. The SPF calculated from the bivariate BrdUrd/DNA distribution was higher in aneuploidy (D2, A1, and A2) than in diploidy (D1) (P < 0.01). Also, A2 exhibited a higher SPF than A1 (P < 0.01). Furthermore, SPF correlated with DNA index significantly (P < 0.01). Patients who showed aneuploid tumors, DNA ploidy type A2, or SPF of more than 10% survived 3 years less than those with diploid tumors, DNA ploidy type D1, or SPF of less than 10%, respectively (P < 0.05). By analyzing with the Coxs proportional hazards model, it is revealed that DNA ploidy and SPF are one of the independent factors of prognostic significance. The results indicated that the patients with aneuploid tumors or highly proliferative tumors had a poor prognosis and that DNA ploidy pattern and SPF were useful prognostic factors for gastric cancers.

Amplification of Epidermal Growth Factor Receptor Gene and Its Relationship to Survival in Human Gastric Cancer

The correlation between the clinical features in 103 patients with primary gastric carcinoma and amplification of epidermal growth factor receptor (EGFR) gene was analyzed retrospectively. EGFR gene amplification was examined by slot-blot hybridization using DNA extracted from formalin-fixed, paraffin-embedded tissues. EGFR expression was also examined immunohistochemically using the same tissues with a monoclonal antibody that is monospecific for EGFR. In 5 of 103 cases (4.9%), a 2- to 11-fold amplification of EGFR gene was detected. Four of these 5 cases were poorly differentiated adenocarcinomas. All of them had overexpressions of EGFR. The cumulative survival rate of patients with EGFR gene amplification was significantly lower than that of the patients without amplification (p < 0.05) and all of them died within 3 years. Except for tumor size (p < 0.03), there were no significant clinicopathologic differences between the two groups. On the other hand, 41 of 103 cases (39.8%) exhibited expression of EGFR. However, there was no significant correlation between EGFR expression and clinicopathologic factors or prognosis. These results indicate that EGFR gene amplification may occur in advanced stages during the progression and be an important indicator of poor short-term prognosis in gastric carcinoma.

Proliferative activity and malignancy in human gastric cancers significance of the proliferation rate and its clinical application

The authors sought useful indicators for predicting the proliferative activity of human gastric cancer and attempted to evaluate its clinical significance. One hundred seventy‐two patients with gastric cancer were entered in this study. All patients received bromodeoxyuridine at 200 to 1000 mg/body before laparotomy. Cell kinetics studies using the migration chase method were done for 56 patients, and the DNA synthesis time (Ts) was found to be prolonged in tumors, especially in aneuploid tumors, compared with normal mucosae. Ts correlated with bromodeoxyuridine (BrdUrd) labeling indices (LI) (r = 0.453, P < 0.0005) and DNA indices (DI) (r = 0.534, P < 0.0005). Thus, the DNA synthesis time was significantly prolonged in the tumors having a high S‐phase fraction or DNA aneuploidy. The result of multivariate analysis indicated that LI/DI was the most potent indicator for predicting the proliferation rate (PR), which was : calculated by the formula LI/Ts, and correlated significantly with PR (r = 0.863, P < 0.0001). As was clear from the result of Coxs proportional hazard model, the predieted proliferation rate (pPR) was the most notable factor for the prognosis because pPR correlated clinically with metastasis, such as that to liver and lymph nodes. The patients with a high pPR (> 10%) had a worse prognosis (4‐year survival rate: 16.3%) than did those with a low value (< 10%) (4‐year survival rate: 85.1%). In vitro pPR obtained by in vitro BrdUrd labeling of the specimens obtained at biopsy correlated significantly with the in vivo pPR (r = 0.960, P < 0.0001). The authors concluded that the proliferation rate was the most important factor in judging the malignancy of human gastric cancers and that this rate should be most helpful in determining the treatment and evaluating the prognosis of individual patients.

Effects of piroxicam and esculetin on the MDA-MB-231 human breast cancer cell line

We investigated the effects of piroxicam, esculetin, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) on a human breast cancer cell line (MDA-MB-231). Both piroxicam and esculetin suppressed cell growth and thymidine incorporation, though esculetin was more active in inhibiting cell growth in the presence of linoleic acid (LA). Esculetin reduced the secretion of LTB independent of LA. Piroxicam reduced the secretion of PGE in the absence of LA but only at higher concentrations in the presence of LA. When the relationship between cell growth and PGE and LTB concentration was evaluated by multivariate regression analysis, cell growth was associated with the PGE and LTB concentration when the cells were treated with esculetin alone or with esculetin and LA. Cell growth was associated only with the PGE concentration when they were treated with piroxicam alone or with piroxicam and LA. Therefore, it appears that the growth of MDA-MB-231 cells in vitro is affected by both lipoxygenase and cyclooxygenase products, though lipoxygenase inhibition is more active than cyclooxygenase inhibition on suppression of cell growth in the presence of LA.

Correlation of c-erbB-2 Protein Expression and Lymph Node Status in Early Gastric Cancer

For the prediction of nodal status of early gastric cancer, sections of formalin-fixed, paraffin-embedded tissue from 220 early gastric cancers were analyzed immunohistochemically, using a polyclonal antibody against erbB-2 protein. The data of erbB-2 protein expression have been correlated with pathologic data, and a logistic regression analysis was made for the estimation of the significant factors responsible for lymph node metastasis. A pattern consistent with cell membrane staining was regarded as most specific for the erbB-2 expression. There were 22 (10%) cancers with evidence of erbB-2 protein expression. Positive staining was associated with only lymph node metastasis. The risk of lymph node metastasis was 3-fold greater in tumors having erbB-2 protein expression than in tumors without the expression. When the erbB-2 tissue status and clinicopathological parameters were entered into the logistic regression analysis, erbB-2 protein expression emerged as one of the independent significant factors for lymph node metastasis. These results indicate that early gastric cancer with erbB-2 protein expression may represent a potential risk of lymph node metastasis.

Association of Immunohistochemical Detection of Urokinase-Type Plasminogen Activator with Metastasis and Prognosis in Colorectal Cancer

We evaluated urokinase-type plasminogen activator (uPA) expression with immunohistochemistry in 90 cases of colorectal cancer and compared it with the clinicopathological findings. Patients who had cancer cells which were stained intensively relative to the background were recognized as uPA-positive patients. The uPA-positive rate was 36.7% (33/90) in total cases. There was a significant correlation was also seen between uPA expression and liver metastasis. Prognosis was poorer in the uPA-positive patients than in the uPA-negative patients. Therefore, uPA may be a good predictor of metastasis and prognosis.

Effect of intra-hepatoarterial infusion of MMC and CDDP for gastric cancer patients with liver metastases

The influence of operative treatment and chemotherapy on the prognosis in 93 gastric cancer patients with liver metastasis was studied. Chemotherapy included the systemic administration of mitomycin C (MMC) (39 patients), an intra-hepatoarterial infusion of MMC (MMC IAC group) (19 patients) and an intra-hepatoarterial infusion of MMC and cisplatin (CDDP) (MMC + CDDP IAC group) (24 patients). Either MMC or MMC and CDDP were given in 1–4 courses every 3–4 weeks from the first one to two post operative weeks. The response rate was 4 per cent (1/23), 29 per cent (5/17) and 73 per cent (17/23) for MMC systemic administration, MMC IAC and MMC + CDDP IAC, respectively, with a significantly high rate of effectiveness for the MMC + CDDP IAC. In addition, regarding the median survival period, the MMC + CDDP IAC group showed 11.8 months, as compared with 2.9 months for other chemotherapeutic treatments, indicating a good prognosis regardless of any possible resection of the primary lesion. A Cox proportional hazard model revealed the treatment by MMC + CDDP IAC alone to be a significant independent factor. These results indicated that MMC + CDDP intra-arterial chemotherapy is an effective approach to gastric cancer with liver metastasis.