THE PATHOLOGY OF POLYOMA INDUCED TUMOURS IN FERRETS.
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One hundred eighty-five dogs with histologically confirmed, measurable malignant tumors were used in a prospective study to determine the response to 2 doses of the anthracycline antitumor antibiotic, doxorubicin. Eighty-three dogs had been refractory to one or more previous treatment modalities (surgery, n = 54; chemotherapy, n = 22; radiation, n = 10; hyperthermia, n = 1; biological response modifier, n = 1). The extent of neoplastic disease was determined immediately prior to and 3 weeks after 2 doses of doxorubicin were administered (30 mg/m2 of body surface area, iv) 21 days apart. Eighty-four percent (n = 157) of the dogs received 2 doses of doxorubicin and were evaluated. Of the 28 dogs ruled ineligible, 4 had serious side effects to the first dose of doxorubicin, and 24 others acquired complications resulting from their malignant tumors. A partial or complete remission was obtained in 41% (64/157) of all evaluable dogs: 26% (11/43) of the dogs with carcinoma, 67% (42/63) of the dogs with lymphoma, and 22% (11/51) of the dogs with sarcoma. Tumors in which there was at least a 50% volume reduction (partial or complete remission) included malignant lymphoma (42/63), fibrosarcoma (1/14), solid follicular thyroid carcinoma (3/13), mammary adenocarcinoma (2/8), hemangiosarcoma (2/8), osteosarcoma (1/6), circumanal carcinoma (3/5), synovial cell sarcoma (2/3), undifferentiated sarcoma (2/3), nasal adenocarcinoma (1/2), liposarcoma (1/2), infiltrating lipoma (1/1), malignant melanoma (1/1), sclerosing mesothelioma (1/1), and neurofibrosarcoma (1/2).(ABSTRACT TRUNCATED AT 250 WORDS)
Hyalinizing spindle cell tumor with giant rosettes (HSCT) is presently considered a low-grade fibrosarcoma and is also considered a variant of low-grade fibromyxoid sarcoma by some. None of the HSCTs in the original series had manifested malignant behavior in the form of metastasis, but since that initial report, 2 patients have been reported with pulmonary metastases and another patient with multiple pulmonary nodules in the absence of an identifiable primary tumor. Our patient is the second recorded case of HSCT with pulmonary metastases at the time of diagnosis. A needle biopsy of the axillary mass in the present case consisted mainly of densely hyalinized collagen, whereas the lung nodules had the characteristic giant collagen rosettes surrounded by a bland spindle cell stroma. This case, in addition to at least 2 others in the literature, has demonstrated that the HSCT is a malignant neoplasm with the capacity to metastasize; however, the presence and even persistence of metastatic lesions in the lung has not altered to date an otherwise indolent clinical course. The fact should not be overlooked that the HSCT is a recently reported entity whose natural history and nosology are subjects of continuing observation, study, and discussion.
BN rats immunized subcutaneously with a viral induced tumor (MST) or with a chemical-induced fibrosarcoma (BC5) were donors of immune spleen cells. Samples of immune spleen cells were tested in vitro against MST and BC5 in a 51Cr release assay before culturing and after 7 days of culture with mitomycin C-treated MST and/or BC5 tumor cells (MSTMit, BC5Mit). These spleen cells were infused in vivo i.v. into x-rayed (400 R) and nonirradiated BN recipients that bore a vascularized and progressive (1 to 1.5 cm in diameter) subcutaneous MST or BC5. Spleen cells from untreated BN donor rats were also tested in vitro and in vivo as controls. Established MST were specifically eliminated by spleen cells immune to MST after culture with MSTMit, but not by spleen cells immune to MST without further culture nor by cultured or uncultured BC5 immune spleen cells and control spleen cells. Also, the growth of BC5 was not affected by MST immune spleen cells cultured for 7 days with MST and/or BC5. Elimination of Moloney sarcoma (MST) in vivo occurred in less than 35 days and was correlated with the generation of cytotoxicity in vitro since only MST immune spleen cells cultured with MSTMit were able to augment significantly their cytotoxic capability in vitro.
In the present study, the expression of P53 and MDM2 proteins were examined in 94 soft-tissue sarcomas (35 malignant fibrohistiocytomas, 15 neurosarcomas, 14 liposarcomas, 13 leiomyosarcomas, 11 fibrosarcomas and 6 dermatofibrosarcomas) by immunohistochemistry. The immunohistochemical findings were correlated with P53 mutation analysis using PCR-SSCP, PCR-HDF and direct sequencing, and MDM2 amplification studies by differential PCR. P53 immunopositivity was found in 25 out of 94 (26.6%) cases. Alterations of the P53 gene were detected in 12 (12.8%) tumors; eight of these tumors revealed P53 immunoreactivity. A high number of P53 positive and P53 mutated tumors were histologically defined as poorly differentiated G3 (64.0% and 75.0%, respectively). MDM2 immunopositivity was revealed in 36 out of 94 (38.3%) cases. MDM2 amplification occurred in 17 tumors (18.1%); only nine of these tumors exhibited MDM2 immunoreactivity. Overall, MDM2 positivity was not associated with MDM2 amplification in 27 out of 94 tumors (28.7%). There was no significant correlation between MDM2 overexpression and histological grade. However, when the samples were stratified by immunophenotype, the majority of tumors (52.5%) with isolated MDM2 overexpression (dissociated from P53 positivity) were defined histologically as low grade (G1 + G2). These results support the notion that besides P53 alterations, MDM2 gene deregulation seems to be an important event in sarcomas evolution. Additionally, the mechanism of MDM2-mediated degradation of P53 protein, without involving stabilization and inactivation of P53 gene, should be considered for better understanding of all features of tumor progression processes.
Experimental immunotherapy with a mixture of allogeneic tumor cells and BCG cell-wall skeleton (BCG-CWS) was carried out against established autochthonous fibrosarcomas induced by 3-methylcholanthrene (MCA) in the subcutaneous tissue of rats. The inhibitory effect on growth in the early stage, tumor-size up to 2 cm in diameter, was significantly observed. No significant difference, however, was shown as compared with the effect of treatment with allogeneic tumor cells alone. That is to say, a more effective inhibition of growth due to the addition of BCG-CWS was not demonstrated.
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C57BL mice are immunized by subcutaneous injection of the T2 syngeneic tumour (MCA fibrosarcoma), followed a week later by surgical removal of the tumour. Such mice can be made hyper-immune by challenging them with mitomycin C-treated T2 cells and they do not develop a tumour after a subsequent inoculum of live T2 cells. Lymph nodes near the site of tumour inoculation are removed after 2 weeks and histological studies show an increase in the number of macrophages and mast cells but not of Lyt-2+ lymphocytes.
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Soft-tissue tumors are similar in their behavior. Benign tumors can be easily resected in most cases, whereas malignant tumors are relentless in their locally invasive characteristics. A clear understanding of the constraints of the pathologist in reaching a confirmed diagnosis and a logical plan utilizing surgery as the major modality of therapy are necessary for successful management of these tumors. It appears that radiation combined with hyperthermia is beginning to play a significant role in the local control of soft-tissue sarcomas and that single or multi-agent chemotherapy may be of benefit in treatment of nonresectable or metastatic soft-tissue sarcomas. For the immediate future, surgery remains the only nonexperimental modality of therapy, but the rapid advances in the other therapy methods are encouraging.
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Hardy-Zuckerman 2 feline sarcoma virus (HZ2-FeSV), isolated from a multicentric feline fibrosarcoma is a replication-defective acute transforming feline retrovirus which originated by transduction of feline c-abl sequences with feline leukemia virus (FeLV) and is known to encode a 110-kilodalton gag-abl fusion protein with tyrosine-specific protein kinase activity (P. Besmer, W. D. Hardy, E. E. Zuckerman, P. J. Bergold, L. Lederman, and H. W. Snyder, Nature (London) 303:825-828, 1983). The nucleotide sequence of the abl segment in the HZ2-FeSV genome was determined and compared with the murine and human v-abl and c-abl sequences. The predicted transforming protein consists of 344 amino acids (aa) of FeLV gag origin, 439 aa of abl origin, and at least 200 aa of FeLV pol origin (p110gag-abl-pol). The 1,317-base-pair HZ2-FeSV v-abl segment (fv-abl) corresponds to 5' abl sequences which include the region known to specify the protein kinase domain. The 5' 189 base pairs of fv-abl correspond to 5' c-abl sequences not contained in Abelson murine leukemia virus (MuLV) v-abl. The mouse c-abl exon which contains these segments was identified, and its nucleotide sequence was determined. Comparison of the predicted amino acid sequence of fv-abl with those of Abelson MuLV v-abl and c-abl revealed five aa differences. The 5' junction between FeLV and abl was found to involve a preferred region in FeLV gag p30 (P. Besmer, J. E. Murphy, P. C. George, F. H. Qiu, P. J. Bergold, L. Lederman, H. W. Snyder, D. Brodeur, E. E. Zuckerman, and W. D. Hardy, Nature (London) 320:415-421, 1986). A six-base homology exists at the recombination site between the parental FeLV and the c-abl sequences. The 3' junction between fv-abl and FeLV pol predicts an in-frame fusion of fv-abl and FeLV pol. A transformed cell line containing a truncated gag-abl-pol protein, p85, that lacks most of the FeLV pol sequences was obtained by transfection of NIH 3T3 mouse cells. This result implies that the pol sequences of the p110gag-abl-pol protein are dispensable for fibroblast transformation. To assess whether the fv-abl segment specifies the unique biological properties of HZ2-FeSV, we constructed a Moloney MuLV-based version of HZ2-FeSV, Mo-MuLV(fv-abl), in which the fv-abl sequences were contained in a genetic context similar to that in HZ2-FeSV.(ABSTRACT TRUNCATED AT 400 WORDS)
The therapeutic results obtained in eight cases of childhood malignant soft-tissue sarcoma are summarized. Male to female ratio was 4:4, four were rhabdomyosarcoma and 5 were defined as Group I/II. Adjuvant combination chemotherapy was administered soon after biopsy (3 cases), or after partial or total resection (3 cases) of the primary tumor. In one case, irradiation was employed and in the remaining case, no further therapy was given after surgery. The three patients who underwent total removal of the tumor followed by adjuvant chemotherapy including adriamycin, and a patient with a partially resected intra-orbital tumor which responded well to a similar form of chemotherapy are currently alive after 26+ to 71+ months. By contrast, four patients whose tumors were too bulky to be resected responded poorly to chemotherapy and died. It must be emphasized that adjuvant chemotherapy is of limited value in the treatment of advanced childhood soft-tissue sarcoma.
The immunohistochemical staining pattern of 18 cases of synovial sarcoma with two epithelial-specific monoclonal antibodies is described. This is compared with normal synovium, cases of giant cell tumour of tendon sheath (benign synovioma) and a variety of spindle celled sarcomas. Sixteen cases of synovial sarcoma showed staining of the epithelial component with at least one antibody. No staining was seen in normal synovium or in giant cell tumours of tendon sheath. A small number of malignant schwannomas contained groups of cells which stained positively whilst other spindle cell sarcomas either did not stain or showed 'cross-reaction' type staining only. These results add weight to the proposition that synovial sarcomas do not arise from normal synovium, despite their morphological similarities, but from mesenchymal connective tissue. It is also shown that immunohistochemical staining with anti-epithelial antibodies will emphasize the biphasic pattern of synovial sarcomas allowing their distinction from other sarcomas.
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