Yasushi Okusa

Surgical strategy for patients with gastric carcinoma with submucosal invasion. A multivariate analysis

Background. Early gastric cancer can be treated by endoscopic excision or simple wedge surgical resection. Standard gastrectomy often is advised if submucosal invasion is found, even though only 15–25% of these patients have lymph node metastases. In this study, the risk of lymph node involvement was examined by multivariate analysis to develop a simple discriminant function for surgical decision making in this setting.

Prognostic impact of stromal cell‐derived urokinase–type plasminogen activator in gastric carcinoma

Urokinase‐type plasminogen activator (uPA) plays an important role in the destruction of the extracellular matrix and basement membrane around cancer cells. In the current study, the authors investigated uPA expression in cancer cells and stromal cells in patients with gastric carcinoma.

Correlation between Telomerase Activity and DNA Ploidy in Gastric Cancer

Telomerase has been reported to be activated in most immortal cells and human cancers. In the present study, we assessed the correlation between telomerase activity and cellular DNA ploidy level in gastric cancer. Telomerase activity was determined semiquantitatively using the telomeric repeat amplification protocol assay, a polymerase-chain-reaction-based assay, in surgical specimens of primary tumors obtained from 36 patients with gastric cancer. No correlation was observed between telomerase activity and the proliferating cell nuclear antigen labeling index. In contrast, a positive linear correlation was observed between telomerase activity and the DNA index (r = 0.59; p < 0.01). Tumor cells with aneuploid patterns showed higher telomerase activity than those with diploid patterns (27.6 ± 5.8 vs. 5.8 ± 1.1%; p < 0.01). Telomerase activity of tumors with liver metastases was significantly higher than activity of those without metastases (34.5 ± 16.6 vs. 11.8 ± 2.4; p < 0.05). There was a trend toward a lower survival rate in 9 patients with a telomerase activity of 20% or higher compared to 27 patients with telomerase activity lower than 20%. These results suggest that the telomerase activity of gastric cancer tissue may reflect the malignant potential of the tumor.

Clinical significance of telomerase activity in biopsy specimens of gastric cancer.

Telomerase has been reported to be activated in most immortal cells and human cancers. The purpose of this study was to assess the clinical significance of telomerase activity in biopsy specimens of gastric cancer. Telomerase activity in endoscopic biopsy specimens obtained preoperatively from 31 patients with gastric cancer was determined semiquantitatively using the telomeric repeat amplification protocol assay, a polymerase chain reaction-based assay. Cancer tissues had significantly higher telomerase activity than adjacent normal tissues (13.9 +/-2.0% vs. 7.0 +/- 0.8%; p < 0.05). The ratio of the telomerase activity in cancer tissues to that in normal tissues (telomerase index) was significantly higher in tumors invading the proper muscle layer or deeper or in tumors with moderate or marked lymphatic invasion than in tumors without these invasive factors (4.7 +/- 1.4 vs. 1.1 +/- 0.1 for depth of invasion and 4.4 +/- 1.3 vs. 1.2 +/- 0.2 for lymphatic invasion; p < 0.05 for both). These results suggest that the analysis of telomerase activity in biopsy specimens might contribute to preoperative assessment of the invasive activity or stage of gastric cancer.

Relationship Between Nodal Stage and the Number of Dissected Perigastric Nodes in Gastric Cancer

To evaluate the rationality of the current nodal staging system in gastric cancer, we retrospectively analyzed 152 patients with perigastric node involvement localized to a single station, in whom the route of metastasis to distant nodes was limited. No significant differences in pathology or survival were observed between patients with stage n1 and those with stage n2–3 nodal involvement, but the mean (standard deviation) number of perigastric nodes dissected was 22.6 (12.6) in those with stage n1 involvement and 18.5 (9.5) in those with stage n2-3 involvement (P=0.04). When perigastric node involvement was localized to station 3, the mean number of dissected station 3 nodes was 7.7 (4.2) in n1 patients and 5.3 (2.8) in n2-3 patients (P=0.04). This tendency was also observed in patients with perigastric node involvement limited to either station 1 (P=0.08) or station 6 (P=0.11). Thus, patients with fewer perigastric nodes may have more lymphatics that bypass perigastric nodes and empty directly into distant nodes, increasing the likelihood of skip metastases. The number of positive nodes, affected to a lesser degree by lymphatic distribution than the location of positive nodes, should be incorporated into the staging criteria.

Immunohistochemical staining for the p53 protein and proliferating cell nuclear antigen in familial clustering of gastric cancer.

Purpose of this study was to assess the role of p53 gene and tumor proliferating activity in familial clustering of gastric cancer.

Effect of Blood Transfusions on Survival after Curative Resection for Advanced Gastric Cancer.

手術前後の輸血が胃癌切除後の予後と関連するか否かを検討した.教室における初発進行胃癌治癒切除症例を入院中の輸血たついて非輸血群144例,輸血量1,000ml未満の少量輸血群72例,1,000ml以上の大量輸血群69例に分けて比較すると,大量輸血群の生存率は非輸血群に比べ有意に低かった.両群間に進行程度の差がみられたため因子別に検討すると,深達度漿膜下層(ss)以上の症例およびリンパ節転移がないか1群までの症例で大量輸血群の生存率が非輸血群に比べ低かった.ss以上の症例では両群間に深達度,リンパ節転移の差はなかった.さらにss以上の症例について生存率に関与しうる11の臨床病理学的因子を選びCoxの比例ハザードモデルによる解析を行うと,周術期の輸血はリンパ節転移,腫瘍最大径,静脈侵襲とならんで有意に予後と関連していた.以上より進行胃癌治癒切除例,特に深達度ss以上の症例では周術期における輸血が切除後の生存率を悪くする可能性が示唆された.