Fumio Endoh

Biodegradable mitomycin C microspheres given intra-arterially for inoperable hepatic cancer. With particular reference to a comparison with continuous infusion of mitomycin C and 5-fluorouracil

Thirty‐two patients with inoperable hepatic cancer underwent intra‐arterial hepatic infusion using mitomycin C (MMC) and 5‐fluorourcil (5‐FU) or intra‐arterial hepatic chemoembolization using heated albumin microspheres containing MMC with an average diameter 45 ± 8 μm. Nineteen of the 32 patients received the MMC microsphere treatment and another 13 received the conventional infusion treatment, lasting for 3.4 months. The administered doses of MMC microspheres were 11.7 ± 11.1 mg as MMC in the 12 with metastatic cancer and 6.9 ± 2.1 mg as MMC in the 7 with hepatocellular cancer (HCC). On the contrary, the 13 patients who underwent conventional infusion had average doses of MMC 34.5 ± 17.3 mg and of 5‐FU 13.4 ± 7.7 g, over 3.4 months. An objective tumor response was obtained in 13/19 (68.4%) under MMC microsphere chemoembolization, compared to 6/13 (46.2%) under the conventional infusion. The average level of CEA in the 12 with metastatic cancer, who underwent MMC microsphere therapy, dropped from 57.7 ng/ml to 16.5 ng/ml, while that in the 10 patients on conventional infusion dropped from 24.0 ng/ml to 17.4 ng/ml; that of alpha‐fetoprotein dropped in all 7 with HCC on MMC microsphere chemoembolization, compared to a fall in 1/3 on conventional infusion. With the MMC microsphere treatment, 5 patients from colorectal cancer lived for 15.6 ± 7.6 months, 2 are alive with a long life expectancy; and 7 patients from gastric or pancreatic cancer lived for only 9.3 ± 3.3 months. In case of conventional infusion, 6 patients from colorectal cancer survived for 8.6 ± 3.2 months; and 4 patients from gastric or gallbladder cancer survived for 6.0 ± 1.0 months. The MMC microsphere treatment is superior at P = 0.059 in survival duration to the conventional infusion treatment. However, much the same survival occurred in 7 on MMC microsphere chemoembolization and 3 on continuous infusion.

Effects of intra-arterially infused biodegradable microspheres containing mitomycin C

We prepared biodegradable microspheres containing about 5% mitomycin C (MMC) and of 45 ± 8 μm in diameter. These preparations were infused into the rat hepatic artery as a preclinical model of intra‐arterial infusion treatment for patients with inoperable hepatic tumor. The leaked MMC levels in the hepatic vein decreased below the assay limitation 2 hours after conventional MMC injection, whereas in the case of MMC microsphere the leaked drug levels were maintained at almost the same concentration for over 2 hours after infusion. The entrapped period of MMC microspheres within the hepatic artery was at least 2 weeks, and the necrobiotic foci due to antitumor effects of the condensed MMC released from the microspheres were observed in the area fed by these entrapped arterioles. This phenomenon was never observed in the case of conventional MMC and placebo microspheres. Intra‐arterial infusion of MMC microspheres may be a promising clinical treatment for patients with malignant hepatic tumor.

A clinical pilot study combining surgery with intraoperative pelvic hyperthermochemotherapy to prevent the local recurrence of rectal cancer

Intraoperative pelvic hyperthermochemotherapy (IOPHC) with mitomycin C (MMC) was prescribed for 14 patients with resectable advanced rectal cancer in an attempt to prevent a postoperative local recurrence. Immediately after rectal amputation and extended lymphadenectomy, IOPHC was performed using physiologic saline containing 40 micrograms/mL of MMC at 45.5 +/- 0.6 C for 90 minutes, with an apparatus devised for IOPHC. At the end of IOPHC, the esophageal temperature was 37.2 +/- 0.8 C and cooling was not required. Antitumor efficacy and complications in the IOPHC group were compared with findings in 12 rectal cancer patients who underwent surgery only within the same period of time. Operation time was not prolonged with IOPHC treatment. In cytologic examinations of the pelvic lavage just before IOPHC treatment, viable cancer cells were detected in 6 of the 14 patients but were never detected in the postoperative exudate drained from the pelvic cavity. Of the 12 patients in the control group, 2 had a local recurrence, while in the IOPHC group there was no local recurrence for 16.9 +/- 9.7 months at this writing. Postoperative complications did not differ between the groups. This IOPHC treatment is a favorable method in eradicating cancer cells for postoperative local recurrence of rectal cancer.

Stapled or manual suturing in esophagojejunostomy after total gastrectomy: A comparison of outcome in 379 patients

From January 1983 to December 1989, we performed esophagojejunostomy on 379 patients who underwent total gastrectomy for gastric cancer. A mechanical EEA stapler or conventional manual suturing was used. The clinical outcomes of 199 patients in whom stapling was used (stapler group) and 180 patients in whom manual suturing was done (manual group) were compared. Two of the 199 patients in the stapler group and 3 of the 180 patients in the manual group died of causes directly related to the anastomosis. In the stapler group, 16 stapled anastomoses were formed supradiaphragmatically, and manual suturing was done for 6 patients. The highly placed anastomosis was formed without left thoracotomy or with median sternotomy in 8 of the 16 patients in whom the stapling device was used and in 1 of the 6 patients in whom manual suturing was used. The incidence of anastomotic leakage and stenosis did not differ between the groups. Thus, the mechanical stapler facilitated the construction of a rapid, reliable esophagojejunostomic anastomosis.

Continued in vitro and in vivo release of an antitumor drug from albumin microspheres

Heated albumin microspheres with an average diameter of 45±8 μm and containing mitomycin C, released, in vitro, about 20% of this antibiotic over a 3-day period. VX-2 tumors were implanted into the hind leg of rabbits and the drug-containing microspheres were injected into the femoral artery of these animals. High levels of the drug were maintained for several hours in the tumor and growth of the tumor was inhibited considerably, compared to findings in control rabbits given the conventional mitomycin C. Half the number of the rabbits treated with our new method are alive with no evidence of tumor.

Two-color flow cytometric analysis of splenic lymphocyte subpopulations in patients with gastric cancer

Lymphocyte subpopulations of the spleen were assayed in 26 patients with gastric cancer and 5 patients with benign disease using two-color flow cytometric analysis. The ratio of Leu 2a+·Leu 15+ cells, or suppressor T cells, in the gastric cancer patients was about 6 per cent, being higher than that in the patients with benign disease (p<0.05). There were fewer Leu 7+·Leu 11− cells, or natural killer-NK-cells, in the gastric cancer patients in stage III or IV than in those with stages I or II (p<0.05). The ratio of Leu 3a+·Leu 8− cells, or helper T cells, in the stage IV patients accounted for about 15 per cent of the splenic lymphocytes, which was less than that seen in the patients in stages I or II (p<0.05). The ratio of Leu 2a+·Leu 15− cells, or cytotoxic T cells, was approximately twice that of suppressor T cells. The pre-operative administration of lentinan plus OK-432 increased the ratio of Leu 4+·HLA-DR+ cells, or activated T cells, and cytotoxic T cells (p<0.05 and p<0.01, respectively). The above results suggest that lymphocyte subpopulations in the spleen may have more immuno-suppressive potential in proportion with the stage of gastric cancer, but that this reduced immune state may be altered when lentinan and OK-432 are given to these patients.

Intra-arterial administration of heated albumin microspheres containing mitomycin C to rabbits with VX-2 tumor

In an attempt to enhance antitumor effects, we prepared heated albumin microspheres containing mitomycin C (MMC). These MMC microspheres have an average diameter of 45±8 μm and contain about 5 per cent of MMC. The intra-arterial MMC microsphere treatment, for albino rabbits with implanted VX-2 tumor, increased remarkably the tissue MMC levels, compared to that with conventional MMC, and resulted in conspicuous antitumor efficacy. This approach to antitumor chemotherapy should be effective for selected patients with malignant tumor receiving a blood supply from an end-artery.

Enhanced antitumor efficacy with a combination of hyperthermochemotherapy and thermosensitization with polyamine antimetabolites in nude mice

In an attempt to enhance the antitumor effects of hyperthermochemotherapy, methylglyoxal-bis-guanylhydrazone (MGBG) and alpha-difluoromethylornithine (DFMO) were used in combination with hyperthermochemotherapy of 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) against human gastric cancer (ST-2) xenotransplanted into nude mice. After priming with DFMO and MGBG, ACNU was given ip and subsequently, a 23 minute-hyperthermia was carried out by placing the leg with the tumor into a water bath of a temperature of 43.5±0.1°C. The second hyperthermic treatment was given in the same manner after 48 hours. MGBG and DFMO were administered for 4 successive days from the previous day of the first hyperthermia. In mice treated with DFMO plus MGBG, either tumor growth or tumor tripling time was much the same as in the control, while in mice given MGBG, DFMO plus heat, there was a diminution in tumor growth. Hyperthermia together with MGBG, DFMO plus ACNU brought about remarkable antiproliferative effects on ST-2 tumor growth, compared to three regimens with MGBG, DFMO plus heat, MGBG, DFMO plus ACNU, as well as ACNU plus heat. These data suggest that a combination of MGBG with DFMO leads to a favorable thermosensitization to the antitumor efficacy of ACNU.

Combined therapy of polyamine antimetabolites and antitumor drugs for human gastric cancer xenotransplanted into nude mice.

Antitumor therapies using polyamine antimetabolites combined with 1-(4-amino-2-methyl-5-pyrimidyl)methyl-3(2-chloroethyl)-3-nitrosourea (ACNU) or fluorinated pyrimidines for human gastric cancer xenotransplanted into nude mice were studied to determine inhibiting post-therapeutic regrowth of the tumor after cessation of antitumor treatments with polyamine antimetabolites alone. ACNU 20 mg/kg, fluorinated pyrimidine, 5-FU 52.8 mg/kg and 5′-deoxy-5-fluorouridine (5′-DFUR) 100 mg/kg as well as polyamine antimetabolites, alpha-difluoromethylornithine (DFMO) 1000 mg/kg and methylglyoxal-bis-guanylhydrazone (MGBG) 50 mg/kg were given intraperitoneally for 5 successive days. When DFMO and MGBG were combined with ACNU, the post-therapeutic regrowth was definitely inhibited, while combined treatments with 5-FU or 5′-DFUR did not inhibit the regrowth. Post-therapeutic DNA biosynthesis was suppressed in mice given DFMO, MGBG plus ACNU. On the contrary, in mice treated with DFMO, MGBG plus 5-FU or 5′-DFUR, suppression of DNA biosynthesis was not observed. Tumor tissue spermine levels in the DFMO, MGBG plus 5-FU or 5′-DFUR group remained unchanged, compared to those in the DFMO + MGBG group. In mice given DFMO, MGBG plus ACNU, however, spermine levels were markedly depressed; and the ACNU alone depressed also the tissue spermine levels. These different results between nitrosourea and fluorinated pyrimidines may relate to mechanisms of action of these antitumor drugs.