Noriyuki Oba

Comparison of doubling times of serum carcinoembryonic antigen produced by various metastatic lesions in recurrent gastric and colorectal carcinomas

The authors measured the serial serum carcinoem‐bryonic antigen (CEA) levels in patients with recurrent gastric or colorectal carcinoma. Among the 45 patients with recurrent gastric carcinomas, those with lung me‐tastases showed the most prolonged CEA doubling time (CEA‐DT), followed by those with liver and peritoneal metastases, respectively. Of the 31 patients with recurrent colorectal carcinomas, those with local recurrence showed the most prolonged CEA‐DT, followed by those with lung, liver, and peritoneal metastases, respectively. A positive correlation was observed for gastric and colorectal carcinomas between CEA‐DT in patients with metastatic lesions and outcome (R=0.84 and 0.93, respectively). The results of the current study suggest that postoperative measurement of CEA‐DT is useful in the determination of region of recurrence of carcinoma, which would permit early surgery and chemotherapy. Measurement of CEA‐DT also may be helpful for the accurate determination of prognosis.

RELATIONSHIP BETWEEN PLASMINOGEN ACTIVATORS AND STOMACH CARCINOMA STAGE

The antigen levels of plasminogen activators (PAs), tissue-type PA (t-PA) and urokinase-type PA (u-PA), were measured in extracts from 30 gastric carcinomas and corresponding normal gastric mucosa. The t-PA level was significantly higher in normal mucosa than in cancer tissue, while the u-PA level was significantly higher in cancer tissue. The u-PA level increased with increasing tumor stage, and there was a significant difference between early and advanced cancer. The u-PA level also increased with the degree of nodal involvement, and it was higher in undifferentiated tumors than in well-differentiated ones. It was higher in cases with venous invasion, liver metastasis or peritoneal dissemination than in cases without these features.

Evaluation of an oleic acid water-in-oil-in-water-type multiple emulsion as potential drug carrier via the enteral route

A water-in-oil-in-water (W/O/W) emulsion composed of oleic acid was used as a carrier of carboxyfluorescein (CF)via the enteral route, as a model for future drug transport. The absorption of CF in the small intestine of rats given the emulsion (W/O/W group) was compared with the absorption in a group administered CF alone (CF group), and a surface-active agent in CF solution (MM group). Higher amounts of CF were absorbed in the W/O/W and MM groups than in the CF group. At 120 min, the amount of CF remaining in the intestinal tract was smaller in the MM group than in the W/O/W group. In the early period, CF excretion into bile was higher in the MM group than in the W/O/W group was higher than in the MM group (non-specific). The blood CF level was significantly higher at 240 and 360 min in the W/O/W group than in the other two groups. The highest concentration in lymph was found in the W/O/W group. The W/O/W emulsion was considered superior to the micelles because it maintained a higher blood level of CF over long periods and transferred it to the lymph. This suggests that the W/O/W emulsion is applicable as a drug carriervia the enteral route.

Metastatic mode of gastric carcinoma by flow cytometric and clinicopathologic parameters

We used flow cytometric and conventional clinicopathologic parameters to analyse the metastatic mode of cancer in 113 stomach cancer patients. Liver metastasis was frequent in cases with intestinal-type cancer, cancer located in the distal stomach, positive venous invasion and aneuploid cancer. Lung and pleural metastasis (excluding nodular lung metastasis), however, were frequent in cases with serosal invasion and diploid cancer. Peritoneal metastasis was frequently seen with tumors located in the proximal or whole stomach, diffuse-type cancer and cancer with serosal invasion. All cases developing bone metastasis were positive for lymph node metastasis. DNA ploidy was partially related to the metastatic mode of stomach cancer, but this was not the sole parameter for predicting metastasis. However, prediction may be possible if based on both DNA ploidy and clinicopathologic parameters, suggesting the possibility of the prophylaxis of recurrence by appropriate postoperative adjuvant therapy.

Video-assisted thoracoscopic esophagectomy in the left lateral decubitus position in an esophageal cancer patient with pectus excavatum.

During thoracic cavity operations, it is difficult to obtain sufficient working space and good operative field visibility in patients with pectus excavatum because the space between the vertebral bodies and sternum is very narrow. Here, we report the successful treatment of esophageal cancer in a patient with pectus excavatum. A 77‐year‐old man with esophageal cancer was referred to our hospital for further treatment. He was diagnosed with multiple early esophageal squamous cell carcinomas. The patient had pectus excavatum, but because it was asymptomatic, a video‐assisted thoracoscopic radical esophagectomy in the left lateral decubitus position without pectus excavatum repair was selected. Despite the patients unusual anatomy, video‐assisted thoracoscopic esophagectomy in the left decubitus position allowed for good operative field visibility, as the videoscope was inserted from the side of the diaphragm. This operative procedure is useful in patients with esophageal cancer who also have pectus excavatum. To the best of our knowledge, this is the second report of video‐assisted thoracoscopic esophagectomy in an esophageal cancer patient with pectus excavatum.

Metastatic mode and DNA ploidy in gastric carcinoma

We studied the amounts of nuclear DNA in gastric cancer metastases histologically and cytochemically by flow cytometry, which was performed retrospectively on paraffin-embedded specimens from 95 patients. At surgery, all cases of aneuploid cancer were positive for lymph node metastases. Liver metastases were frequently seen in aneuploid cancer (63%, P<0.01), while lung metastases were the most common in diploid cancer (50%, P<0.05). The incidence of peritoneal metastasis was high in undifferentiated diploid cancer (72%, P<0.01). Local lymph node recurrence after surgery was more common in aneuploid than in diploid cancer (P<0.01). The incidence of bone and distant lymph node metastasis was found to be strongly dependant on tissue differentiation. The DNA ploidy pattern is thus considered to be closely linked to lymph node, liver, and lung metastases in gastric cancer.