Takao Ishizuka

Seven Tumor Markers in Benign and Malignant Germ Cell Tumors of the Ovary

Seven tumor markers were analyzed clinically in 135 patients with germ cell tumors of the ovary who were treated in Tokai Ovarian Tumor Study Group, an association comprising Nagoya University and its affiliated hospitals, between January 1979 and September 1990. Positive rate of AFP was 100% (36/36) in yolk sac tumor, 61.9% (13/21) in immature teratoma, and 11.8% (2/17) in dysgerminoma, but there were no positive cases of mature cystic teratoma with malignant transformation (0/7) and mature cystic teratoma (0/31). Positive rate of CA125 was over 50% in all tumor types except mature cystic teratoma, which showed a positive rate of 23.7%. CA125 was useful for the screening of malignant germ cell tumors. CA19-9 showed a high positive rate in teratomatous tumors, which were immature teratoma, mature cystic teratoma with malignant transformation, and mature cystic teratoma. Dysgerminoma and yolk sac tumor, especially dysgerminoma, had a high positive rate of LDH. TPA and CEA were not considered useful tumor markers for germ cell tumors of the ovary.

Intracranial metastasis of choriocarcinoma. A clinicopathologic study

In an attempt to improve the diagnosis and treatment of intracranial metastases of choriocarcinoma, the authors carried out a clinicopathologic investigation of 36 patients with choriocarcinoma metastasized in the brain. Analysis on the autopsy findings of 30 cases with documented intracranial metastases of choriocarcinoma proved neurosurgical resectability in most cases. After initiation of the clinical use of dactinomycin in 1965, 5 of 10 patients in the surgically treated group, and 1 of 17 in the group without surgery, survived for more than 6 months after development of neurologic symptoms. Intracranial metastases of choriocarcinoma should be treated as follows: (1) if symptoms of increased intracranial pressure progress to a life‐threatening situation, removal of tumor or, at least, decompression should be immediately performed; (2) multidrug chemotherapy supplemented by whole‐brain irradiation should be started within several days after surgery; and (3) if symptoms are not present, chemotherapy combined with irradiation is the first treatment of choice.

Polyembryoma of ovary producing alpha-fetoprotein and HCG: Immunoperoxidase and electron microscopic study

Polyembryoma of ovary producing alpha‐fetoprotein (AFP) and human chorionic gonadotropin (HCG) was studied by indirect immunoperoxidase method for AFP and HCG, and electron microscopy. Clinically, this patient showed pseudoprecocious puberty caused by elevated HCG which is synthesized by trophoblastic cells in polyembryoma. She is put under VAC (vincristine, actinomycin‐D, cyclophosphamide) chemotherapy after operation and shows no signs of recurrence including reelevation of serum AFP at five months after operation. Embryoid bodies which we studied correspond to normal embryo at 15‐ or 16‐day stage. Immunoperoxidase study showed that AFP is synthesized by yolk sac cells of the embryoid bodies and HCG is synthesized by syncytiotrophoblastic cells. The finding about AFP synthesis suggests that normal embryo at 15‐ or 16‐day stage may begin AFP synthesis. Electron microscopic study showed that each part of the embryoid bodies had some characteristic structures. Most striking features found in the cytodifferentiation of the embryoid bodies were noticed in some special differentiation of plasma membrane and existence of surface coat. Desmosomes were found in endodermal cells and yolk sac cells. Ectodermal cells were attached to each other by zonulae occludentes and adhaerentes. Microvilli were found in ectodermal cells and yolk sac cells. Two different kinds of surface coat were found in mesodermal cells and lining cells of yolk sac cavity: thin‐layered deposit of electron‐dense material covering the plasma membrane facing intercellular space of mesodermal cells and endodermal cells, and thick‐layered deposit of electron‐dense material which covered the plasma membrane facing yolk sac cavity of endodermal cells and yolk sac cells. Presence of similar characteristic material in RER of yolk sac cells led us to speculate that thick deposit was synthesized by yolk sac cells and secreted into yolk sac cavity. Combined with immunoperoxidase study by light microscopy, we assume that this thick‐layered deposit has some close relation to AFP.

Randomised study of immunotherapy with OK-432 in uterine cervical carcinoma

OK-432, a streptococcal preparation, was administered to patients with stage Ib and II cervical carcinoma except for adeno- and adenosquamous carcinomas. To evaluate the efficacy of OK-432 precisely, 177 patients were stratified by clinical stage, radiotherapy, and lymph node metastasis after complete radical hysterectomy and pelvic lymphadenectomy. Within each stratum, patients were divided randomly into OK-432 and control groups. 85 patients received OK-432 and 92 patients did not. No significant difference was observed in overall 5-year disease free rates between the OK-432 and the control groups, although the mean diameter of erythema on SU-polysaccharide (SU-PS) skin test was larger in the OK-432 group than in the control group. In stage IIb, a significant difference was observed between the OK-432 and control groups. This difference, however, could be attributed in part to the different incidence of the lymph node metastasis. In stage II without lymph node metastasis, 5-year disease free rate was significantly higher in the OK-432 group.

Histopathologic classification of uterine choriocarcinoma.

Histopathologic features of uterine choriocarcinoma were studied to establish new criteria for grading malignancy of the disease. Thirteen items of histopathologic findings concerning the degree of differentiation and the forms of masses of trophoblasts (Trs), the manner of Tr invasion, and host response of surrounding tissues were studied with relationship to prognosis in 70 patients with uterine lesions (alive, 49; dead, 21). Chi‐square test results were examined for each item in relation to prognosis of the patients. Four items were thought to have significance and were selected as criteria: (1) island formation; (2) massive proliferation of intermediate‐type Trs; (3) rectangular infiltration of Trs to surrounding muscle fibers; and (4) atypia of Trs at the end‐point of tumor invasion. A discriminant analysis was carried out (under the standardization of tumor extension and the historical staging of treatment). From the results obtained in discriminant analysis, scores were given to the four items that existed in the specimen. New criteria for grading malignancy are proposed based on scoring these four items. The algebraic sum of the scores had a possible range of +4 to −16. Patients with scores of −9 and above had a low‐grade malignancy with a mortality rate of 7%. Patients with scores of −10 and lower had a mortality of 69% and were classified as having tumors of high‐grade malignancy.

Methotrexate-induced resistance to dactinomycin in choriocarcinoma

NaUCC‐2, a choriocarcinoma cell line, was derived from a patient who had a very poor clinical response to combination chemotherapy. Methotrexate (MTX) might have inhibited the antitumor effect of dactinomycin. To investigate this point, in vitro studies were performed to determine the sensitivity and uptake of MTX and dactinomycin (administered individually and in combination) to NaUCC‐2 and three other choriocarcinoma cell lines. Dihydrofolate reductase (DHFR) concentrations were studied as well. Although NaUCC‐2 showed sensitivity to MTX and dactinomycin, which were comparable to the other cell lines when they were given separately, NaUCC‐2 was unique in that the combination of MTX and dactinomycin was less lethal than dactinomycin given by itself. The uptake of MTX in NaUCC‐2 was significantly higher than that in the other cell lines, and MTX also induced an increase in dactinomycin uptake in NaUCC‐2. There was no significant difference in DHFR activity. Although additional studies are necessary to determine the mechanism responsible for this effect, these findings suggest that a mechanism other than drug uptake or DHFR activity must play a role in the drug resistance for choriocarcinoma. These findings also suggest that the most commonly used combination chemotherapy for choriocarcinoma, dactinomycin and MTX, may not always be the best method.

Prophylactic effect of bestatin on the onset of invasive mole — clinical and fundamental studies

This study was performed to determine whether bestatin (Ubenimex) has clinical prophylactic effects on the onset of invasive mole and a direct inhibitory effect on the growth of hydatidiform molar cells. A total of 49 patients with hydatidiform mole treated at Nagoya University Hospital from 1984 to 1990 were randomly divided into two groups, a bestatin administered-group and a bestatin non-administered group. Patients in the bestatin group were given 30 mg of bestatin orally and daily for three months just after their molar deliveries. There was no significant difference in age, gravidity, parity and gestational weeks between the two groups. There was also no significant difference in the duration of human chorionic gonadotropin (hCG) negative conversion in patients without invasive mole between the two groups. However, the incidence of invasive mole in the bestatin group (2/25, 8%) was significantly lower than that of the non-bestatin group (7/24, 29.2%). Nevertheless, there was no significant difference between the two groups in such immunological parameters as PHA skin test, PPD skin test, PHA stimulation index (PHA-SI), white blood cell (WBC) count lymphocytes % per WBC, OKT 3% per lymphocytes, OKT 4% per lymphocytes, OKT4/OKT8 and Leu 11% per lymphocytes. In vitro studies were performed with primary cultured hydatidiform moles. The result was that bestatin inhibited the secretion of hCG and3H-thymidine uptake of hydatidiform molar cells. Thus, a possibility was suggested that bestatin directly inhibits the growth of hydatidiform molar cells and prevents the onset of invasive mole.

Mechanism of Methotrexate-sensitivity of Choriocarcinoma Cells in Culture

Four cell lines established from choriocarcinoma were compared for sensitivity to methotrexate (MTX). In this paper, we have compared the relative gene copy number of dihydrofolate reductase (DHFR), the target enzyme of methotrexate (MTX), in order to clarify whether or not amplification of the gene is involved in the relative resistance to MTX observed for one of the cell lines, designated NaUCC‐1, which is 4‐ to 5‐fold more resistant to MTX as compared with the other cell lines and exhibits a reduced uptake of [3H]MTX. Neither dot blot nor Southern blot hybridization revealed any significant difference in the gene copy number among the four cell lines. Therefore, the resistance to MTX of the NaUCC‐1 line is explained by a reduced uptake of the drug, rather than amplification of the target gene.

Determination of phosphatidylglycerol in amniotic fluid for prediction of foetal lung maturity by microbore-column liquid chromatography.

Phosphatidylglycerol (PG) has been determined in amniotic fluid from 55 patients by using a microbore-column liquid chromatographic system. The present analysis time is 1 h 40 min for pretreatment of amniotic fluid and 20 min for a chromatographic run. From 2 ml of amniotic fluid, the PG content has been determined between 1.0 and 0.05 mg/dl. The detection limit of PG is 10 ng. As the injection volume (0.5 microliter) is small, repeated analyses are possible if necessary. It is concluded that, in the case of PG values over 0.10 mg/dl, a mother can deliver an infant without respiratory distress syndrome. This method is useful not only for the prenatal evaluation of lung maturity, but also for the assessment of any therapeutic effect.