[Selective tumour chemotherapy using oncobiograms (author's transl)]

Intra-arterial preoperative cytostatic treatment versus preoperative irradiation: A prospective, randomized study of lingual and sublingual carcinomas

BACKGROUND

For several decades, both preoperative intra-arterial chemotherapy and preoperative irradiation have been accepted treatments for patients with tumors of the head and neck. Unfortunately, arguments have often been put forward in favor of one or other of the two methods, but without the performance of an objective, randomized investigation. To resolve this situation, the authors have carried out a multicenter, randomized prospective study of selected patients with a view to deciding which method affords better results in complex tumor therapy from the aspects of survival and postoperative quality of life.

METHODS

One hundred thirty-one patients with operable sublingual or lingual squamous cell carcinoma in stages T2NXM0 to T4MXM0 were randomized into 2 groups: 1 group participated in preoperative chemotherapy with cisplatin and epirubicin (total doses: 200 mg cisplatin, 120 mg epirubicin) via the external carotid artery, whereas the other group received preoperative radiation therapy (46 grays). Following subsequent radical surgery, the patients received regular follow-up for 5 years.

RESULTS

By the end of the 5 years, 95 of the 131 patients had conformed to the protocol. Of those 95, 47 had received preoperative chemotherapy and 48 preoperative irradiation. After 5 years, 18 of the 47 patients who received chemotherapy and 15 of the 48 patients who received irradiation were still alive and tumor free. A few more patients had died of recurrence or regional metastasis in the chemotherapy group (23 patients) than in the irradiation group (20 patients). Occurrence of a second carcinoma was 3 times as frequent in the irradiation group (9 patients) as in the chemotherapy group (3 patients). Overall, the survival rates were by-and-large the same for the two groups. Regarding postoperative quality of life, the chemotherapy group presented a more favorable picture.

CONCLUSIONS

The long term survival results subsequent to preoperative intra-arterial chemotherapy or preoperative radiotherapy were practically the same. Regarding postoperative quality of life, patients who underwent intra-arterial chemotherapy appeared to be in a slightly more favorable situation. The authors consider it important to stress these findings, as they are not aware of a similar randomized study of patients with tumors of the oral cavity.

Three tumor sensitivity tests evaluated with mouse tumors

The predictive value of three types of tumor sensitivity tests was evaluated using mouse tumors. Sensitivities of osteosarcoma C22LR, Lewis lung and M2661 carcinoma were determined for the following drugs: DNA interacting or alkylating agent (doxorubicin, cisplatin, 1,3-bis(2-chloroethyl)-1-nitrosourea, melphalan), antimetabolite (5-fluorouracil, methotrexate) and microtubule inhibitor (vinblastine, vincristine). Volume measurements of the subcutaneously growing tumors after treatment with the same drugs were considered to be the traditional reference system with which the results of the in vitro clonogenic assay, the labeled precursor incorporation assay and the subrenal capsule assay were compared. Results obtained with the in vitro clonogenic assay were highly reproducible. With the 1-h drug exposure technique the predictive accuracy was 71%. This result is in the same range as those found by others for human tumors. Predictive accuracy after continuous drug exposure was only 25%. Vinblastine, vincristine and cisplatin caused no inhibition of labeled precursor incorporation. However, the assay is too unreliable to use, due to the extreme variability when used with the other drugs. From 31 consecutively performed duplicate tests in the subrenal capsule assay, nine showed opposite results. This degree of disagreement between duplicate test results was considered too high to make reliable predictions of tumor sensitivity with this assay.

Application of an in vitro antimetabolic assay to human germ cell testicular tumors for the preclinical evaluation of drug sensitivity

An in vitro assay, which evaluates the effect of drugs on labeled nucleotide precursor incorporation 3H-thymidine and 3H-uridine after 3 hours of in vitro treatment, was applied to human germ cell testicular tumors. The assay was feasible on 78% of the 259 tumors, and the results were evaluable in 95% of these, which shows the good potential of its clinical application. In vitro response rates to conventional agents were comparable to clinical response rates reported in the literature for monochemotherapy regimens, thus demonstrating the accuracy of the assay in reproducing the sensitivity of the tumor type. The specificity of the assay in predicting drug sensitivity of individual tumors was investigated on 28 lesions from 24 patients who had residual disease after surgery. A significant correlation was found between in vitro and clinical sensitivity to the same drugs (P = 0.026), with an overall agreement of 92% when tumor metastases were tested in vitro. In contrast, no significant correlation, and a poor agreement (62%) was found when the primary tumor was tested.

Effects of chitin synthesis inhibitors on incorporation of nucleosides into DNA and RNA in a cell line from Manduca sexta (L)

Five putative chitin synthesis inhibitors (CSI) were tested to determine if they inhibited nucleoside incorporation into acid precipitable material in a cell line from Manduca sexta (L.). The results varied. Diflubenzuron (DFB) (100 micron) inhibited cytidine incorporation by 38%; EL-494 (100 micron) inhibited adenosine incorporation by 43%; Bay Sir 8514 (100 micron) inhibited uridine incorporation by 24%. Superdiflubenzuron (100 micron) was the worst inhibitor overall (18-22%) for the benzoylphenyl urea CSI. The triazine CSI, CGA 19255, was the best inhibitor tested with 60% inhibition for cytidine and 49% for adenosine incorporation into DNA and RNA. Examination of cells incubated with diflubenzuron by scanning electron microscopy revealed distinct external morphological changes. Transmission electron microscopy showed that crystalline structures accumulated in the cytoplasm of cells treated with DFB. The crystalline structures were assumed to be diflubenzuron and they persisted even after diflubenzuron was removed from the medium.

In vitro and in vivo investigations for the development of cytostatic methylhydrazones

In in vitro short-term (3 h) assays, the beta-chloroethyl-methyl-hydrazones B 1 and B 2 inhibit the uptake of 3H-thymidine by EAC and L 1210 leukemia cells, B 2 being 5 to 10 times more effective than B 1. The growth inhibitory effect of both compounds was also confirmed in long-term (7 days) clonal assays using agar-containing glass capillaries, B 2 again being more effective than B 1. In contrast to these differences in vitro, in vivo both substances showed remission to the same degree in EAC- and complete resistance in L 1210-bearing mice. The diverging in vitro/in vivo sensitivities were thought to result from differences in the affinity of the methylhydrazones to the tumor cells: using short exposure periods (3 h) B 1 was more inhibitory than B 2 on both EAC and L 1210 colony growth; i.e., the more hydrophilic B 2 could more easily be washed off. To further test the idea of different cell membrane affinities, the methylhydrazones ZB 1 and P 1 with increasing lipophilic properties were synthesized. In vitro, after both pulse and continuous exposure ZB 1 and P 1 showed enforced inhibitory effects on colony growth. In vivo, ZB 1 and P 1 reduced the tumor weight of EAC mice, while only P 1 increased the survival time of L 1210 mice. The results suggest that from the combination of in vitro/in vivo assays mechanistic conclusions can be derived that are valuable for further development of these cystostatics.

Diagnosis and staging of ovarian cancer

The diagnostic process in ovarian carcinoma is divided into the pre- and intraoperative procedures, examinations of tumor tissue, and follow-up. For preoperative diagnosis, the probability of a palpable adnexal mass being a malignant tumor should first be ascertained by sonography. This should be followed by an appropriate general examination, a search for tumor outside the abdominal cavity and in the liver parenchyma as well as by determination of markers. Intraoperative diagnosis determines the tumor stage and must be carried out all the more comprehensively when the ovarian carcinoma is more limited. Histologic subtype and degree of differentiation are in direct relation to the tumor stage, whereas the size of the primary tumor is often indirectly proportional to its extent. Besides the morphological analysis, the determination of possible chemoresistance and chemosensitivity, as well as further investigations on fresh tumor tissue are included in the tissue examination. Follow-up after a curative operation consists of gynecologic examination and Douglas lavages if tumor is still present in CT Scans and sonographs. To verify a relapse, laparoscopy can be used, but to ascertain a complete remission, a laparotomy is necessary.

Considerations on the carcinogenicity of the mushroom poison gyromitrin and its metabolites

Monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH), but not N-methyl-N-formylhydrazine (MFH), a mushroom poison, can be oxidized by the weak oxidant 2,6-dichlorophenolindophenol. Hydrogen peroxide is formed by this oxidation, and has been found to cause decay of DNA in aqueous solution as measured by the decreased viscosity of a DNA solution in the presence of the hydrazines. Furthermore, MMH and UDMH but not MFH inhibit the incorporation of [3H]thymidine and [3H]uridine into DNA and RNA of Ehrlich ascites carcinoma (EAC) cells. These experiments show that MFH is an inactive compound in contrast to MMH and UDMH. Since the hydrolysis rate of MFH, to produce MMH, is low, it is concluded that MFH must be activated in vivo into toxic metabolites which are ultimately responsible for the known high carcinogenicity of MFH.

[In vitro and in vivo sensitivity of animal and human melanomas to various chemotherapeutical agents]

Thin slices of s.c. implanted B-16 melanomas as well as of human melanomas have been incubated for 5 h with (H3) Uridine and (H3) Thymidine in the presence of different chemotherapeutical agents, whose concentration was equivalent to the tenfold therapeutical daily dose in men. In this short term test model, the sensitivity of a melanoma to a chemotherapeutical agent is indicated by the inhibition of the nucleoside uptake by more than 50%. The in vitro sensitivity rates, each based on 10--30 melanomas, are compared to the in vivo sensitivity rates. Sensitivity is indicated by the increase of life span (greater than 25%) in the melanoma bearing mice respectively by the regression of human melanoma metastases (greater than 50%). -- The in vivo sensitivity of the B-16 melanomas, evaluated by the uridine and/or thymidine uptake, was in line with the in vivo sensitivity to all chemotherapeutical agents with the exeption of Adriamycine and DTIC. The in vitro sensitivity of human melanomas to Dactinomicine, Vincristine, BCNU and DTIC corresponds to the in vivo sensitivity whereas no in vitro/in vivo correspondence could be observed in testing Bleomycine, Procarbacine and 5-Fluorouracile. Comparing the sensitivity of B-16 and human melanomas, similarity was observed in vitro but not in vivo.

[On the problem of praetherapeutic sensitivity testing of human tumours based on incorporation studies of nucleic acid precursors in vitro (author's transl)]

Praetherapeutic sensitivity tests of human solid tumours based on incorporation studies of nucleic acid precursors have been described by various authors. This review intends to show that such tests may only be of rather limited value for the design of individual chemotherapeutic regimens. In many drugs, a correlation between biochemical and clinical effects has not yet been established. The reliability of praetherapeutic sensitivity tests is further impaired by general methodological difficulties of short-term cultures, individual pharmacology and toxicology of cytostatic agents as well as pharmacological and biochemical drug interactions in combination chemotherapy. Praetherapeutic testing with individual cytostatic drugs is discussed.

[Investigations about the incorporation of nucleotide precursors in single cell suspensions of ovarian- and cervix-carcinomas under the influence of cytostatic therapy (author's transl)]

The behaviour of 34 carcinomas of the cervix and 30 ovarian carcinomas under the influence of cytostatic agents was investigated in vitro by the method of Volm et al. The ovarian carcinomas showed a significantly higher incorporation rate of nucleotide precursors in the single cell suspensions. The incorporation rate in "chemosensitive" carcinomas was higher than in "chemoresistent" carcinomas independent of the type of the carcinomas. Carcinomas with a high decrease in incorporation rates of nucleotide precursors under the influence of cytostatic drugs were called chemosensitive. A cyclophosphamide-sensitivity in vitro was found in 9% of the carcinomas of the cervix and in 34% of the ovarian carcinomas. An adriamycin-sensitivity in vitro could be shown in 17% of the carcinomas of the cervix and in 46% of the ovarian carcinomas. These findings agree well with the experiences of cytostatic therapy of these carcinomas.

[Studies on the thymidine-triphosphate synthesis in malignant tumors. II. Effect of hyperthermia, Vitamin K and Cytotoxic agents (author's transl)]

Measurements of the deoxyribonucleoside triphosphate (dNTP) contents, the [14C] thymidine and deoxyuridine incorporation and the "key enzymes" of the thymidine triphosphate (dTTP) synthesis, thymidine kinase and ribonucleotide reductase, in diploid Ehrlich-ascites carcinoma, under the application of hyperthermia, vitamin K and cytocidal agents show: The effect of hyperthermia and menadion (the basic substance of the K vitamins) on the above parameters of dNTP synthesis can explain the labile effects of hyperthemia and vitamin K therapy on cancer growth. Alterations of the dNTP concentrations and demonstrable or absent inhibition of the ribonucleotide reduction with application of fluoruracil, amethopterine, cytosine arabinoside, hydroxyurea, trisethylen iminobenzochinone and daunomycin confirm and supplement our knowledge of the cytostatic action mechanism of these substances. They show moreover by the example of fluoruracil and amethopterine medication that the dTTP concentration estimation after in-vitro incubation of tumour cells with the addition of FU or methotrexat is a better measurement of the therapeutic in-vivo responsiveness of malignant tumours than the previously performed test methods.

Human mammary cancers in nu/nu-mice. A model for testing in research and clinic

37 (85%) of 44 human breast cancers are successfully transplanted on thymus-aplastic nu/nu-mice without adjunctive immunotherapy. 16 weeks after transplantation 4 rapidly growing tumours are showing human, female karyotypes. Subsequent investigations proved a good correlation between original tumour and transplant: histology, 3H-thymidine marking index and receptors of androgen and estorgen.

Clinical correlates of in vitro effect of adriamycin on advanced lung carcinoma

The effect of 1.38 X 10(-5) M adriamycin on tritiated uridine incorporation was studied after 3 hours treatment of suspensions of 25 advanced human lung carcinomas in vitro. The results were correlated with the responses to clinical therapy. All tumours which showed an inhibition of uridine incorporation in vitro of more than 40% were also sensitive to clinical treatment with adriamycin.

[The evaluation of the cyclophosphamide sensitivity of human tumours by determining the incorporation of tritiated uridine and thymidine into the nucleic acids of human tumor cells in vitro in presence of 4-hydroxycyclophosphamide (author's transl)]

A new in vitro assay for screening the sensitivity of human tumour cells against Cyclophosphamide has been developed. While biologically activated Cyclophosphamide was unsuitable because of unpurities in the material, synthetic 4-Hydroxycyclophosphamide was shown to inhibit the incorporation of tritiated uridine and thymidine into the nucleic acids of human tumour cells in vitro. 29 tumours including 14 mammarial carcinomas, 8 ovarial carcinomas and 7 other malignant tumours were tested. While 12 tumours showed a significant and 5 only a slight inhibition of the 3H-uridine incorporation in vitro. 12 tumours showed no effect. Histologically none-differentiated tumours were more sensitive against 4-Hydroxycyclophosphamide as compared with the more differentiated ones. First observations point to 4-Hydroperoxycyclophosphamide instead of 4-Hydroxycyclophosphamide as a more suitable form of activated Cyclophosphamid for the in vitro assay of Cyclophosphamide sensitiveness because of the higher stability and better availability of this compound.

[The effect of cyclophosphamide on tumors in the sensitivity-test (author's transl)]

The sensitivity of tumors to cyclophosphamide was tested in vitro. For this purpose, the urine of cyclophosphamide-treated rats (90 min., 500 mg/kg) was used. This method of activating cyclophosphamid proved more advantageous than other methods; all cytostatically effective metabolites can be used in the test and the production of metabolites can easily be standardized. Consequently results with good reproducibility can be obtained. In various long-term and short-term test models with animal transplantation-tumors in vitro, the effects of the cyclophosphamide metabolites depended on the dose used. This test results in the various test models are comparable. In the tissue-culture of tumors (long-term test) sensitivity was evaluated by using morphological criteria as well as by counting cell numbers. In the short-term test the sensitivity of tumors was found out by influencing the nucleic acid syntheses (3-H-thymidine-, 3-H-uridine-incorporation). As the tissue-culture meets with difficulties as a routine clinical examination, the use of the short-term test is recommended. Using as model the fast proliferating WALKER-256-carcinosarcoma and a slowly proliferating rat adenocarcinoma, the results of the sensitivity-test in vitro were compared with the effects of therapy in animal tests. Tumor remissions corresponding with the results reached in vitro, which depended on dosis, could also be achieved in both transplantation-tumors. Human tumors, tested in in vitro studies (short-term-test), show a different sensitivity to cyclophosphamide.

Sensitivity tests of tumors to cytostatic agents. I. Comparative investigations on transplanted tumors in vivo and in vitro

With series of transplanted tumors, the activities of different cytostatic agents which directly influence the metabolism of nucleic acids (Actinomycin D, adriamycin, daunomycin, 5-fluorouracil, procarbazine, trenimon) was measured by determining 3-H-uridine incorporation in short-term (3hrs) incubations of tumor cell suspensions. Data obtained could be used to predict the response of each tumor to particular cytostatic agents in vivo. The activities of the cytostatic agents as determined using long-term tissue cultures (time of exposure of tumor cells to cytostatic agent 48 hrs were comparable to those obtained with the short-term test. In long-term cultures, determination of cell numbers gave results similar to those obtained by morphological evaluation. In SHORt-term test, differing sensitivities of tumors to cytostatics could be detected.