Hidenori Mukaida

Clinical significance of the expression of epidermal growth factor and its receptor in esophageal cancer

The epidermal growth factor receptor (EGFR) level in 56 esophageal cancer tissues was measured by 125I‐EGF binding assay to elucidate its role in tumor progression. The survival rate of patients with high EGFR level (more than 50 fmol/mg protein) was significantly lower than that of patients with low EGFR level (less than 50 fmol/mg protein, P less than 0.01), although a correlation between EGFR level and the pathologic findings was not observed. The expression of EGF was examined immunohistochemically using anti‐EGF monoclonal antibody in 100 esophageal cancer tissues; EGF‐positive tumor cells were detected in 92.0%. The immunoreactivity of EGF was classified arbitrarily into four grades according to the number of stained tumor cells. The expression of EGF significantly correlated with the differentiation of esophageal squamous cell carcinoma (P less than 0.01, by chi‐square test). The survival rate of patients with high EGF immunoreactivity (Grade 2 or 3) was much lower than in those with lower grade (0 or 1) tumors, (P less than 0.01). Patients with both high EGFR level and EGF immunoreactivity had a much worse prognosis than if both were low. Furthermore, the mitotic index was higher in groups with both high EGFR and EGF than if both were low (16.39 ± 5.35 versus 6.90 ± 3.31). These results suggest that EGF and EGFR in the autocrine system may play an important role in tumor progression in esophageal cancer and their expression could be of prognostic significance.

Relationship between epidermal growth factor receptor status and various prognostic factors in human breast cancer

Relationship between epidermal growth factor receptor (EGFR) status and various prognostic factors was investigated in 91 human breast cancer tissues. Epidermal growth factor receptor was measured by biochemical competitive binding assay using iodine 125 epidermal growth factor (125I)‐EGF. The EGFR status was not correlated with axillary lymph node involvement, tumor size, stage, and histologic type, but significantly correlated with histologic grading (P < 0.05) and lymphatic invasion (P < 0.01). Between EGFR and estrogen receptor (ER) status, a clear inverse relationship was observed (P < 0.01). The Ki‐67‐positive stained cell rate, which reveals the proportion of cycling cells, was significantly higher in EGFR‐positive tumor tissues than in EGFR‐negative cases. Furthermore, preliminary postoperative survey demonstrated a high tendency of recurrence rate of patients with EGFR‐positive tumors as compared with those with EGFR‐negative tumors. These data suggest that EGFR status may be important for the prediction of biologically high malignant potential.

POOR PROGNOSIS IN ESOPHAGEAL CANCER PATIENTS WITH POSTOPERATIVE COMPLICATIONS

We investigated the relationship between postoperative complications and prognosis in esophageal cancer patients. Two hundred five patients with esophageal cancer were divided into three case groups. Group A (n = 100) consisted of cases without postoperative complications. Groups B (n = 58) and C (n = 47) consisted of cases with minor and major postoperative complications. The 5-year survival rates were 41.8%, 21.3%, and 20.2% in groups A, B, and C, respectively. There was a significant difference in the prognosis between groups A and B, and also between groups A and C. Any patients who died within 5 years without a relapse their cases were excluded from the study; the 5-year survival rates were 46.7%, 32.3%, and 22.5% in groups A, B, and C, respectively, with a significant difference between groups A and B. There were no significant differences between the three groups regarding the patient characteristics. These results therefore indicate that postoperative complications might contribute to a poor prognosis in cancer patients.

LAPAROSCOPIC RESECTION OF SUBMUCOSAL GASTRIC TUMORS

In order to elucidate the efficacy in gastric surgery, we evaluated seven resected cases of a submucosal gastric tumor in which laparoscopic techniques were used. The patients consisted of 1 man and 6 women. The tumors were located in the upper, middle, and lower third of the stomach in 4, 1, and 2 cases, respectively. Three tumors were located mainly on the anterior gastric wall, 2 were on the posterior wall, and 2 were on the lesser curvature. The resected tumor size averaged 3.2×2.6 cm. The tumors were classified as intraluminal type (4 cases) and the extraluminal type (3 cases) according to the classification of growth type. A histopathological examination identified 4 leiomyomas, 1 leiomyosarcoma, and 4 smooth muscle tumors of indeterminate malignant potential. After a tumor resection, no recurrence of the lesions occurred during the postoperative follow-up. An extraluminal growing tumor was easily resected by the laparoscopic method without any additional procedures, and this therefore seemed to be a good indication for the laparoscopic method. In contrast, an intraluminal tumor was found to be more difficult to resect using the laparoscopic method without a companion method, e.g., intraoperative endoscopy, because of the difficulties in the detection and resection of the tumor from the serosal side. A more efficient technique must therefore be developed for this type of tumor.

Antineoplastic effect of erbstatin on human mammary and esophageal tumors in athymic nude mice

The growth of MCF-7, a human mammary carcinoma, in athymic nude mice was inhibited by intraperitoneal administration of erbstatin for 14 days in combination with an iron chelator, foroxymithine, which inhibits the decomposition of erbstatin. Another human mammary carcinoma, Br-10, was not affected. Foroxymithine alone had no anti-tumor activity. In four esophageal tumors, erbstatin retarded tumor growth. There were no side-effects in any erbstatin-treated group. Levels of epidermal growth factor receptors were not changed throughout treatment with erbstatin at any dose. Erbstatin, a tyrosine kinase inhibitor, may have an antineoplastic effect against human mammary and esophageal tumors.

Detection of androgen receptors in human esophageal cancer

The incidence of esophageal cancer is much higher in men than in women and the prognosis is generally worse in men than in women. This seems to depend on the difference in the hormonal environments of the patient. In this paper, androgen receptors (AR) were measured in 21 cases of human esophageal cancer. Of these, two cases of esophageal cancer xenografts implanted into nude mice were AR positive. In EH-1, an established cell line from human esophageal cancer, the number of binding sites was increased and tumor growth was enhanced by testosterone administration. On the other hand, the number of binding sites was decreased and tumor growth was suppressed by castration. The administration of estrogen, however, did not inhibit tumor growth.

Expression of human epidermal growth factor and its receptor in esophageal cancer

The expression of human epidermal growth factor (hEGF) was examined immunohistochemically in 86 esophageal cancer lesions, comprising 67 primary tumors and 19 metastatic lymph nodes. In the normal esophagus, the parabasal and intermediate cell layers showed a weak expression of hEGF, however, hEGF-positive tumor cells were detected in 62 (92.5 per cent) of the 67 primary esophageal carcinomas and in 18 (94.7 per cent) of the 19 metastatic lymph nodes. In this study, the immunoreactivity of hEGF was classified into 4 grades according to the number of stained tumor cells. A significant correlation was observed between the histologic type and the grade of hEGF immunoreactivity (Chisquare test, p<0.01). hEGF immunoreactivity in well differentiated squamous cell carcinomas was significantly higher than in other squamous cell carcinomas, although there were no correlations between other pathological findings and hEGF immunoreactivity. Patients with hEGF immunoreactivities of grades II or III had much worse prognoses than those with grades 0 or I (p<0.05). In 22 esophageal carcinomas and 10 normal esophageal mucosae, EGF receptor (EGFR) contents were measured by the competitive binding assay. The average EGFR content (101.3±35.7 fmol/mg protein, mean±SE) of the esophageal carcinomas was significantly higher than that (5.3±1.2) of the normal esophageal mucosae (p<0.05). Moreover, in hEGF negative tumors, EGFR contents were lower than in hEGF positive tumors. These results suggest that hEGF and EGFR show increased production in squamous cell carcinomas and could to be useful prognostic factors in patients with esophageal cancer.

Finger bougie method compared with pyloroplasty in the gastric replacement of the esophagus

To elucidate the necessity of pyloroplasty for the gastric tube through the posterior mediastinum in esophageal surgery, gastric emptying and duodenogastric reflux (DGR) were evaluated in 16 cases undergoing an anterior pylorectomy (group P) and in 16 cases treated by the finger bougie method (group F). First, the obstruction and reflux symptoms were examined based on a patient questionnaire using a brief scoring system. The median value of the symptom score showed the patients in P to have more symptoms than those in F; however, the difference was not significant (8.0 vs 6.0). Secondly, the swallowed Tc O4− (85 MBq) was counted using a gamma camera at three sites on the sternal bone in the upright position based on a gastric transit scintigram. Both the descending time of the RI peak and the clearance rates were similar between the two groups. Thirdly, intragastric 24-h pH monitoring was carried out. Antimony pH sensors were anchored 5 and 15 cm below the esophagogastrostomy. We could not find any difference between the two groups in both the % time pH>4 and %time pH>7. These findings thus revealed no big difference between groups P and F. The finger bougie method to drain the vagotomized posterior mediastinal stomach was found to achieve results similar to conventional pyloroplasty, while it was also simpler and safer.

Bypass operation for advanced esophageal cancer —An analysis of 93 cases—

From 1973 to 1987, 235 patients with esophageal squamous cell carcinoma were treated at Hiroshima University. Of these patients, 121 (51.5 per cent) were submitted to esophagectomy, 93 (39.6 per cent) to bypass surgery and 21 (8.9 per cent) to either exploratory or no surgery. In this report, the 93 cases who underwent bypass surgery were analysed. Ten patients died within thirty days after their operation (10.8 per cent) and there were 33 cases of hospital death (35.5 per cent). Following the bypass surgery, 49 (59.0 per cent) cases were able to tolerate over 50 per cent of their normal oral intake and 22 cases (26.5 per cent) were able to tolerate between 25 per cent and 50 per cent. For twelve cases (14.6 per cent), however, oral ingestion proved impossible up until the time of death due to such complications as leakage. The overall survival rates were 44.3 per cent at 6 months, 12.7 per cent at 1 year and 2.8 per cent at 5 years, respectively. Two cases survived for over 5 years. Hyperthermia was applied in combination with chemotherapy from 1981, however, no case survived for over one year without radiation therapy. Recently, radiation plus hyperthermia is being performed in combination with immunochemotherapy.

Clinical evaluation of adjuvant chemoradiotherapy with CDDP, 5-Fu, and VP-16 for advanced esophageal cancer

OBJECTIVES The aim of this study was to evaluate the efficacy of adjuvant chemoradiotherapy following surgery in patients with advanced esophageal cancer. SUBJECTS AND METHODS We followed the cases of 57 such patients treated at our hospital, involving 19 who received adjuvant chemoradiotherapy (CR group), 19 who received radiotherapy alone (R group), and 19 who did received neither (N group). In the CR group, chemotherapy, consisting of cis-diaminodichloroplatinum (CDDP), 5-fluorouracil (5-FU), and etoposide (VP-16), was combined with radiotherapy was administered from 4 weeks after surgery. Concurrent radiotherapy was started at 3 weeks after esophagectomy. CDDP at 50 mg/m2 was administered on days 1 and 7.5-FU at 500 mg/m2 and VP-16 at 60 mg/m2 were administered on days 3, 4, and 5. Thirteen patients (68.4%) were treated with more than 2 cycles of chemotherapy combined with radiation. RESULTS Side-effects of severe anorexia (grade 3) and leukocytopenia (< 1900/microliter) were observed in 47% and 39% of the patients, respectively. However no treatment-related death was observed. The 5-year-survival rate was 25.2%, 18.9%, and 15.8%, in the CR group, R group, and N group, respectively. The recurrence rate was 66.7% in the CR group, which was higher than in the matched control groups (46.2% in the N group and 54.5% in the R group), but with no a significant difference. CONCLUSION These results suggested that adjuvant chemoradiotherapy did not contribute to improvement in prognosis for these patients with advanced esophageal cancer.