[Cancer metastasis and recurrence from the standpoint of amplification and expression of oncogenes in human malignant tumors]

We investigated the amplification and expression of oncogenes in human malignant tumors. The survival rates of patients with c-erbB, c-erbB-2, and int-2 oncogene amplification/expression were significantly lower than those of the patients without gene amplification/expression. Many distant organ metastases were observed in esophageal cancer patients with int-2 amplification, in gastric cancer patients with c-erbB-2 over-expression, and in breast cancer patients with int-2 and c-erbB-2 amplification. These results suggest that the amplification/expression of these oncogenes may serve as good markers for determining the biological malignancy of cancers.

[Response to rechallenged tamoxifen of metastatic breast cancer relapsed after surgical adjuvant tamoxifen treatment]

Tamoxifen (TAM), an antiestrogen was administered 20 mg b.i.d. to 20 patients with recurrent breast cancer at the time of first relapse who had been treated with the adjuvant therapy including TAM 10 mg b.i.d.. Patients who had been treated with TAM at least 1 year and in which the relapse had occurred after 3 months or more after the cessation of adjuvant treatment were enrolled in the study. Sixteen patients were evaluated, and a complete response was observed in 3 (19%), partial response in 1 (6%), no change in 5 (31%), and progressive disease in 7 (44%). The response rate was shown to be 25% with 95% confidence interval: 3.8-46.2%. The duration of response ranged from 23+ to 32 weeks. Patients who have received postoperative adjuvant therapy including TAM and have relapsed after the cessation of therapy may retain hormone dependency in responding to a further TAM treatment at the time of relapse of malignancy.

[Preclinical screening of chemotherapeutic and endocrine agents using human tumor xenografts--nude mouse system]

Although newly developed antitumor agents had been screened using cultured human cell lines and rodent tumor systems, it was apparent that the positive antitumor activity of the agents on these experimental tumors is not a sufficient but a necessary condition to elucidate the antitumor activity on clinical human cancers. We have clarified that the chemosensitivity of human gastric, breast colon carcinoma xenografts could reproduce the essentially identical chemosensitivity of clinical carcinomas when the maximum tolerable doses of the conventionally available agents were administered to tumor bearing nude mice, and human breast carcinoma xenografts had a similar estrogen dependency and endocrine sensitivity to clinical human breast cancer. These findings indicated that the human tumor xenografts--nude mouse is an appropriate model to predict the clinical antitumor activity of newly developed antitumor agents.

Endothelin-1 inhibits adipogenic differentiation of 3T3-L1 preadipocytes

The effect of endothelin (ET)-1 on the adipogenic differentiation of 3T3-L1 preadipocytes was examined. Cellular morphology and lipoprotein lipase activity were used as differentiation markers. ET-1 inhibited the hormone-induced adipogenic differentiation of 3T3-L1 preadipocytes morphologically and biochemically in a dose-dependent manner. These findings promote ET-1 as a potent inhibitor of adipogenic differentiation, playing an important role in cellular differentiation of preadipocytes and making it a significant regulator of lipid metabolism.

[Antitumor activity and toxicity of KB-5424 R, a newly developed antitumor platinum compound]

KB-5424 (ab-(3-aminopyrrolidine)-cd-[glycolato (2-)-0, 0'] platinum (II) is a newly developed antitumor platinum compound which was synthesized at Kanebo Institute for Cancer Research. When the antitumor activity of KB-5424 was evaluated using several rodent tumors, no significant differences were observed between the antitumor activities of KB-5424, cisplatin (CDDP) and DWA-2114 R (DWA). KB-5424 was divided into two kinds of optical isomers, KB-5424 R and KB-5424 S, of which antitumor activity was compared each other. The maximum increased life span (ILSmax) on L 1210 of KB-5424 R was almost equal to that of CDDP and better than those of KB-5424 S and carboplatin (CBDCA). The antitumor activity of KB-5424 R on a human tumor xenograft MX-1 was almost identical to those of CDDP and CBDCA and better than that of DWA. Since the nephrotoxicity of KB-5424 R was significantly reduced comparing with CDDP, this newly developed antitumor platinum compound was thought to be a promising agent for the clinical application.

[Modified operation for an early stage gastric cancer]

The standard operation for gastric cancer is carried out for advanced gastric cancer with serosal invasion accompanying patent disseminative metastasis to the peritoneum of the omental bursa and lymph node metastases. It consists of subtotal or total gastrectomy, omentobursectomy and extended lymph node dissection. An early stage cancer, which in Japan accounts for almost a half of the resectable cases of gastric cancer, shows no serosal invasion, and lymph node metastases are rare if the cancer remains intramucosal. Such cases represent about a half the cases of the early stage cancer. The diagnosis of the early stage cancer, especially if it remains intramucosal, is made by means of preoperative radiological and endoscopic examinations and intraoperative examination. Since 1977 we have been performing a modified operation as well for cases of the early stage cancer. The surgical procedure is as follows: reduction in the size of gastric resection by 2/3, pylorus-preserving gastrectomy and proximal gastric resection; preservation of the distal portion of the greater omentum and transverse incision of the upper abdomen instead of upper midline incision to prevent ileus due to intestinal adhesion to abdominal wound around umbilicus; sparing bursectomy; narrowing the area of lymph node dissection; sparing thoracotomy for cancer in the esophagogastric junction; sparing splenopancreatectomy; preservation of the hepatic branch of the vagal nerve and postoperative temporary oral administration of cholagogue to prevent postgastrectomy cholelithiasis. In addition, the primary lesion is isolated from the blood circulation by means of ligation of the drainage veins to diminish metastasis through the blood vessels (hepatic metastasis, etc.), which is the main cause recurrence after surgery for the early stage cancer. The results of this new surgery are satisfactory; the five-year postoperative survival rate is 100.0% and it reduced the time needed for surgery, anesthesia and blood transfusion.

Location of the disulfide bonds in the antitumor protein neocarzinostatin

Two disulfide bonds in the antitumor antibiotic neocarzinostatin were determined chemically. The peptic and peptic/thermolytic peptides from the native protein were isolated by gel filtration and ion-exchange chromatography followed by reverse-phase HPLC. The cystine peptides obtained were oxidized separately by performic acid treatment and further separated by HPLC into cysteic acid peptides. Sequence analyses of the isolated peptides revealed the location of the disulfide bonds at Cys37-Cys47 and Cys88-Cys93.

In vitro and in vivo antitumor effects of murine monoclonal antibody NCC-ST-421 reacting with dimeric Le(a) (Le(a)/Le(a)) epitope

A murine monoclonal antibody (MAb), NCC-ST-421 (IgG3), was raised by using a human gastric cancer xenograft St-4 as immunogen. Immunization was achieved by transferring immunocompetent normal BALB/c mouse spleen cells into BALB/c-nu/nu mice bearing St-4 tumors. Hybridomas were produced from spleen cells of the mice after rejection of the tumors and were screened for preferential reactivity with cancers on formalin-fixed paraffin sections, as described previously for establishment of MAb NCC-ST-439 (M. Watanabe et al., Jpn. J. Cancer Res., 76: 43-52, 1985). The immunobiological and immunochemical properties of the new MAb NCC-ST-421 are described here. The MAb is essentially directed to a structure with dimeric Le(a) (V4III4Fuc2Lc6Cer) epitope (Gal beta 1----3[Fuc alpha 1----4]GlcNAc beta 1----3Gal beta 1----3[Fuc alpha 1----4]GlcNAc beta 1----3Gal beta 1----4Glc beta 1----1 Cer). It cross-reacts with Le(a) but does not show any effect on Le(a)-positive RBC in vitro or on Le(a)-positive tissue loci in vivo. ST-421 strongly induced antibody-dependent cellular cytotoxicity using human peripheral blood leukocytes as effector cells with a variety of human tumor cells, using the short-term 51Cr release assay. It also showed striking complement-dependent cytotoxicity with a human complement source and was able to produce lysis of a variety of human cancer cell lines, supporting its observed ability to cause cytotoxic suppression of tumor growth in nude mice. In another series of experiments, i.p. injection of ST-421 completely inhibited growth of human tumor xenografts in nu/nu mice, and this inhibitory activity was closely dependent on expression of the dimeric Le(a) antigen on the cell surface. While Le(a) antigen was expressed in the kidneys of nu/nu mice, infusion of ST-421 in these mice did not cause histological change in kidney tissue. This finding suggests that the MAb does not damage normal cells or tissues which contain cross-reacting Le(a) antigen. These results demonstrate that ST-421 exerts a significant antitumor effect in vitro as well as in vivo, does not affect Le(a) antigen expressed on normal tissues, and therefore has potential application in therapy of certain types of human cancer which express the dimeric Le(a) antigen.

Antitumor activity of fluoropyrimidines and thymidylate synthetase inhibition

Experimental chemotherapy with 5-fluorouracil (5-FU; 60 mg/kg), 1-hexylcarbamoyl-5-fluorouracil (HCFU; 70 mg/kg), 3-(3-(6-benzoyloxy-3-cyano-2-pyridyloxycarbonyl)benzoyl)-1-ethoxym ethyl-5- fluorouracil (BOF-A2; 30 mg/kg) and UFT (20 mg/kg as tegafur with uracil at a molar ratio of 1:4) was performed using human gastric (H-111) and colon (Co-4) carcinoma strains in nude mice. 5-FU was administered ip with a q4d x 3 schedule and the other agents were given po daily for three weeks. Concentrations of 5-FU in the serum and the tumor were assessed by gas chromatography-mass fragmentography, two hours or 12 days (5-FU) after the last treatment, and thymidylate synthetase (TS) was assayed according to the method of Spears et al. using the same schedule. The antitumor activity of the agents was assessed in terms of the actual tumor weight at the end of the experiment. HCFU was effective against both strains and 5-FU was effective against Co-4, although the other agents were ineffective against either strain. Statistically significant correlations were found between the serum and tumor concentrations of 5-FU and antitumor activity. Statistically significant correlations were also observed between the antitumor activity and TS inhibition rate (TSIR) and the activity of free thymidylate synthetase (TSfree), with higher TSIR and lower TSfree resulting in higher antitumor activity. Therefore, TSIR and TSfree were thought to be promising indicators for predicting the antitumor activity of fluoropyrimidines.

Significance of int-2/hst-1 coamplification as a prognostic factor in patients with esophageal squamous carcinoma

The correlation between the clinical outcome in patients with esophageal squamous cell carcinoma and coamplification of the proto-oncogenes int-2 and hst-1, which are partially homologous to angiogenesis-inducing fibroblast growth factor, was analyzed retrospectively. Coamplification of these genes was examined by slot-blot hybridization using DNAs extracted from formalin-fixed and paraffin-embedded blocks of tissues. These tissues were obtained from 107 patients with esophageal squamous cell carcinoma who had undergone radical surgery. Int-2/hst-1 coamplification greater than 3-fold was observed in the primary tumors of 30 of 107 cases (28%), and in the metastatic lymph nodes of 12 of 40 cases (30%). The cumulative survival rate of patients with int-2/hst-1 coamplification in the primary tumors was significantly lower than that of the patients without coamplification (P less than 0.001), and there were no significant differences between the clinicopathological backgrounds of the 2 groups. Int-2/hst-1 coamplification was also significantly correlated with a high incidence of eventual metastasis in distant organs in these patients. These results suggest that int-2/hst-1 coamplification is a new biological indicator of prognosis and distant organ metastasis in patients with esophageal squamous cell carcinoma.

[Cooperative study of surgical adjuvant chemotherapy for colorectal cancer (third report): five-year results. Cooperative Study Group of Surgical Adjuvant Chemotherapy for Colorectal Cancer in Japan]

A randomized controlled study was carried out by the envelope method with 491 institutions in participation across the country in order to find an optimal surgical adjuvant chemotherapy for curatively resected colorectal cancer. The schedules for drug administration were different in four districts: ACNU + Futraful (FT) group and FT alone group in the Hokkaido-Shikoku district; the same schedule groups plus untreated group in the Chubu-Kinki district; MMC+FT group, FT alone group in the Tohoku-Kanto district; and ADM+FT group and FT alone group in the Chugoku-Kyushu district. The numbers of patients admitted to this study were 2,450 cases with colon cancer and 2,456 cases met the evaluation criteria of this study. The 5-year survival rate on the whole did not differ from combination therapy to single drug therapy in either colon cancer or rectal cancer, but in Dukes C rectal cancer the five-year survival rate tended to be higher with the combination therapies. In n2 (+) or a2(s) rectal cancer in particular, combination therapies with MMC and FT and with ADM and FT achieved significantly higher five-year survival rate, and the rate of local recurrence was significantly lower with ADM+FT.

Japanese early phase II study of droloxifene in the treatment of advanced breast cancer. Preliminary dose-finding study

Droloxifene, a new tamoxifen (TAM)-derived compound, has excellent antiestrogenic activity. This compound exhibits less endogenously estrogenic but higher antiestrogenic activity, with better tolerability than TAM in experimental models. Two phase II studies of droloxifene were performed in 47 Japanese institutions to assess the optimal dose. The first was a randomized comparative study using 20, 40, and 80 mg, respectively, once a day. The other was a pilot study using 120 mg once a day. The subjects of both studies were women with primary or recurrent advanced breast cancer, regardless of estrogen receptor status and menopausal status. Of 94 patients enrolled in the comparative study, 22, 26, and 23 were evaluable in the 20-, 40-, and 80-mg groups, respectively. Of the 71 evaluable patients, 14 (19.7%) were negative for estrogen receptor, and 36 (50.7%) had a previous history of TAM therapy. The response rate complete response + partial response (CR + PR) was 13.6% for 20 mg, 15.4% for 40 mg, and 17.4% for 80 mg. The rate of no change (NC) was 31.9%, 46.1%, and 47.8%, and that of progressive disease (PD) was 54.5%, 38.5% and 34.8%, respectively, in the 20-, 40-, and 80-mg groups. In the other study, 16 patients were enrolled in the pilot study with 120 mg of droloxifene, of whom 14 were evaluable. The response rate was slightly higher: four responders (28.6%) were assessed as CR + PR, six (42.9%) as NC, and four (28.6%) as PD. These results suggest that the response rate may be dose-dependent and that PD rates seem lower in the higher doses. No serious side effects were encountered, and droloxifene was well tolerated even in the higher doses. At present, a final randomized dose-finding study with 80 mg/day and 120 mg/day is being carried out.

[Experimental combined chemo- and endocrine therapy with UFT and tamoxifen in human breast carcinoma xenografts serially transplanted into nude mice]

We have investigated the experimental combined chemo- and endocrine therapy of UFT and tamoxifen (TAM) on two human breast carcinoma xenografts, R-27 and Br-10 with estrogen receptors (ER) serially transplanted into nude mice. When sc inoculated tumor started the exponential growth, the treatments were initiated in four groups which were control, UFT 20 mg/kg (as tegafur) po daily for 18 times, TAM 5 mg/kg im twice a week for 6 times and UFT + TAM groups. The antitumor activity of the agents were assessed by the growth curves, the lowest T/C ratios of the relative mean tumor weight and the actual tumor weights at the end of the experiments. TAM alone was effective on both R-27 and ineffective on Br-10, while UFT alone was ineffective on R-27 and Br-10. The combination antitumor activity was observed in R-27 but not in Br-10. When 5 mg of TAM per kg and 20 mg of UFT per kg as tegafur was administered daily po for 2 wk, there were no statistically significant differences between the concentration of 5-FU in UFT alone and UFT + TAM groups for the two strains. By the assay of ER and progesterone receptors using the same specimen, it was observed that ER was stable by the treatment of UFT, while ER was suppressed by the treatment of TAM in both tumor strains. In addition, this suppression of ER by TAM alone was enhanced by the combined treatment with UFT in both the strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical study of pirarubicin for breast cancer in Japan. Clinical Study Group of THP for Breast Cancer in Japan

The efficacy and toxicity of (2''R)-4'-O-tetrahydropyranyl adriamycin (THP) were assessed in the treatment of patients with advanced breast cancer by the Japan THP Study Group. Mean plasma levels of THP after single-dose administration revealed triexponential decay characterized by an initial half-life of 0.89 h. A higher concentration of THP was obtained in the metastatic lymph nodes than in the breast cancer tissue at 4 h after administration (4.01 vs. 1.17 micrograms/g). Whereas 1 complete (CR) and 12 partial response (PR) were observed in 56 evaluable patients after administration of THP alone (23.2%), 1 CR and 12 PR were observed in 37 evaluable patients who had combination therapy including THP (35.1%). Multivariate analysis of prognostic factor revealed that the site of metastases had the most valuable prognostic significance; second was irradiation in the previous treatment, and third was the disease-free interval. Life-table analysis adjusted with the Cox proportional hazard model revealed a similar survival curve of patients receiving THP-cyclophosphamide, adriamycin, and 5-fluorouracil (CAF) to that of those receiving CAF only in spite of the low incidence of toxicity in the THP therapy.

[MTT assay using fresh surgical specimens with reference to the transfer system and reproducibility in "test center" method]

A chemosensitivity test (MTT assay) was conducted using 59 fresh surgical specimens collected from Keio University, Kitasato Institute Hospital and 14 affiliated hospitals, in order to assess the specimen transfer system and the reproducibility of the assay results obtained at Keio University and Kitasato Institute Hospital. Although the optical density yielded by the tumor cells in a number of 5 x 10(4)/well and the number of evaluable cases were significantly reduced through the transfer, the chemosensitivity pattern of the specimen was identical before and after the transfer. Fifty seven of 59 cases were evaluable and the concordant rate of the assay results between the two institutes was 80.6% (108/134) among each case-drug combination. Since the transfer system of the specimen was established and the reproducibility of the assay results in two institutes was confirmed, the "test center" method of the MTT assay appears to be possible by collecting the surgical specimens from the affiliated hospitals.

Antitumor activity and pharmacokinetics of a morpholino-anthracycline derivative (KRN8602) against human breast carcinoma xenografts serially transplanted into nude mice

The antitumor activity and pharmacokinetics of (7R, 8S, 10S)-10-((3-deamino- 3-(4-morpholino)-2,3,6-trideoxy-alpha-L-lyxo-hexopyranosyl)oxy)-8- ethyl- 7,8,9,10-tetrahydro-1,6,7,8,11-pentahydroxy-5,12-naphthacenedione hydrochloride (KRN8602) were evaluated using five human breast carcinoma xenografts in nude mice. The maximum non-toxic dose of KRN8602 was 2 mg/kg by q4d x 3 intraperitoneal and peroral administration. KRN8602 showed significant antitumor activity against MX-1, which is less sensitive to adriamycin, with the chemotherapeutic indices of 13.0 for po administration and 9.5 for ip injection. Although KRN8602 also inhibited the growth of T-61 significantly, the antitumor activity of this agent against the other three breast carcinoma xenografts was limited. To elucidate this discrepancy, pharmacokinetic analysis and MTT assay were conducted using the KRN8602-sensitive MX-1 and KRN8602-insensitive R-27. While no differences were observed in the area under the curve and the peak concentration of KRN8602 for each tumor, a difference in the sensitivity of the tumor strains was obvious in MTT assay. The efficacy of this agent seemed to depend on the sensitivity of each type of tumor cell rather than the concentration of agent in tumor tissues. If it were possible to select patients with sensitive tumor cells to this agent by the MTT assay, the phase II trial might be completed within a short period by reducing the number of studied patients.

[Preoperative oral antimicrobial bowel preparations in elective colorectal surgery]

Colorectal surgery is associated with high incidence of postoperative wound infection due to contamination of the field of operation by organisms from the intestine. A consecutive series of 300 patients undergoing elective operations on the colon and rectum, was studied to determine the efficacy of oral antibacterial preparations on the influence of intestinal organisms at operation and the incidence of postoperative wound infection. The patients were divided into four groups as their preoperative bowel preparations as follows; 1st group: mechanical preparation alone, 2nd group: mechanical preparation and oral kanamycin, 3rd group: mechanical preparation and oral kanamycin and metronidazole, and 4th group: mechanical preparation and oral polymyxin B and metronidazole. The results of bacteriological studies on specimens taken by swab from colonic lumen and wound at operation showed effectiveness of kanamycin and polymyxin B against aerobic gram-negative rods and metronidazole against anaerobes. The rates of postoperative wound infection were 47.5% in 1st group, 27% in 2nd group, 12% 3rd group, and 2.7% in 4th group, respectively.

A phase I study of toremifene

A Phase I study of the new antiestrogenic drug toremifene was carried out in 27 Japanese women, using oral doses of 10-480 mg per day for one or five days. Serum concentrations reached a dose-dependent maximum 2-6 hours after each oral administration. Side effects were generally mild.

Nude mouse resists hepatic metastasis of the allogeneic tumor, colon-26

The ability of the host-immune defense mechanism of nude mice and their immunocompetent littermates to prevent liver metastases from the murine colon carcinoma, colon-26, was assessed. Give thousand tumor cells suspended in 0.05 ml of Hank's balanced salt solution were inoculated into the spleens of BALB/c nu/+ and BALB/c nu/nu mice. On the 21st day after inoculation, all the mice were sacrificed, and the liver metastases counted and the livers weighed. All the BALB/c nu/+ mice were found to have developed hepatic metastases with a mean of 10 nodules, whereas no hepatic metastases were observed in any of the 10 BALB/c nude mice. On the other hand, 4 of 6 nude mice developed hepatic metastases after treatment with anti-asialo GM1 antibody. These results indicate that the BALB/c nude mouse has an excellent host-immune defense mechanism for preventing liver metastasis, with NK cells in the liver and/or blood circulation perhaps playing an important role.

The antitumor effects of adriamycin entrapped in liposomes on lymph node metastases

Adriamycin (ADM) entrapped in liposomes (Lip-ADM) was prepared and its therapeutic effects studied using the mouse leukemia cell line, P388, which metastasized to axillary lymph nodes after inoculation into the foot pads of CDF1 mice. Lip-ADM injections (7.5 mg/kg) were given into the foot pad at two-day intervals. Two series of experiments were performed; one in which Lip-ADM was administered on days 1,3 and 5 following tumor inoculation, and the other in which it was administered on days 5 and 7. Both Lip-ADM injection regimens significantly inhibited metastases to the lymph nodes as compared with mice given injection of saline solution. Furthermore, the therapeutic effects of three Lip-ADM injections were significantly greater than the effects of free ADM. Histological examinations of lymph nodes revealed that three injections of Lip-ADM completely eliminated tumor cells, whereas viable tumor cells were still observed in the lymph nodes after treatment with free ADM. The results of this study suggest that Lip-ADM is useful for the treatment of lymph nodes metastases and that the local injection of Lip-ADM, through such means as endoscopy, would be recommended as a clinical mode of application.

[Phase I study of FK 435]

We performed phase I study of FK 435, a new antiestrogen, in 30 patients with advanced breast cancer. Slight to moderate adverse reactions were noted as follows. Single-dose study: anorexia, nausea, lassitude in one patient (80 mg), decreased serum calcium in one (160 mg), redness, tenderness in one, facial flushing, hot flushes, headache in one (320 mg). Repeated-dose study: anorexia, nausea in one patient (40 mg/day), anorexia, diarrhea, increased FSH in one, increased PRL in one (80 mg/day). FK 435 was well tolerated. Tmax was 3-5 hours, T1/2 about 25 hours. Most of FK 435 was excreted into urine as glucuronide.

Atrial natriuretic polypeptide after burn injury: blood levels and physiological role in rats

To define the relationship between atrial natriuretic polypeptide and the physiological changes of water and electrolytes after burns, the changes in plasma hormonal levels, including atrial natriuretic polypeptide, and urinary water and sodium excretions were examined in burned rats. Further, to elucidate the physiological significance of atrial natriuretic polypeptide after burns, the effects of a specific antiserum against atrial natriuretic polypeptide were determined in burned rats. Plasma atrial natriuretic polypeptide levels in rats following 30 per cent BSA full skin thickness burns were elevated for sustained periods (432.3 +/- 156.5 pg/ml, P less than 0.01 on day 1 postburn, 244.5 +/- 73.7 pg/ml, P less than 0.05 on day 3 postburn). Urine volume and sodium excretion decreased significantly during the first 72 h after burns. On day 3 postburn, urine volume and sodium excretion began to increase significantly. Specific rabbit antiserum against atrial natriuretic polypeptide was injected into the burned rats during this diuretic phase. Significant inhibition of diuresis and natriuresis was observed after the injection of antiserum (27.5 +/- 2.4 per cen decrease in urine volume, 57.1 +/- 10.4 per cent decrease in sodium excretion). These results suggest that atrial natriuretic polypeptide plays a physiological role in the regulation of urinary water and sodium excretion after burns.