A practical approach to the clinical diagnosis of Ewing's sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue.

BACKGROUND: Over 90% of Ewing's sarcoma/primitive neuroectodermal tumour (ES/PNET) cases have the t(11;22) chromosomal rearrangement, which is also found in other small round cell tumours, including desmoplastic small round cell tumour (DSRCT) and clear cell sarcoma (CCS). Although this rearrangement can be analysed by fluorescence in situ hybridisation (FISH) using routinely formalin fixed, paraffin wax embedded (FFPE) tissues when fresh or frozen tissues are not available, a sensitive and convenient detection method is needed for routine clinical diagnosis. AIMS: To investigate the usefulness of newly developed probes for detecting EWS rearrangement resulting from chromosomal translocations using FISH and FFPE tissue in the clinical diagnosis of ES/PNET, DSRCT, and CCS. METHODS: Sixteen ES/PNETs, six DSRCTs, and six CCSs were studied. Three poorly differentiated synovial sarcomas, three alveolar rhabdomyosarcomas, and three neuroblastomas served as negative controls. Interphase FISH analysis was performed on FFPE tissue sections with a commercially available EWSR1 (22q12) dual colour, breakapart rearrangement probe. RESULTS: One fused signal and one split signal of orange and green, demonstrating rearrangement of the EWS gene, was detected in 14 of 16 ES/PNETs, all six DRSCTs, and five of six CCSs, but not in the negative controls. CONCLUSIONS: Interphase FISH using this newly developed probe is sensitive and specific for detecting the EWS gene on FFPE tissues and is of value in the routine clinical diagnosis of ES/PNET, DSRCT, and CCS.

Thallium-201 scintigraphy to assess effect of chemotherapy in osteosarcoma.

UNLABELLED: Imaging results in patients with high-grade osteosarcoma of the extremities were reviewed to determine whether scintigraphic appearance correlated with histologic response to preoperative chemotherapy. METHODS: Histologically, the percent tumor necrosis in specimens from 30 patients were classified into three grades: grade 1 = necrosis less than 60%, grade 2 = 60%-89% necrosis and grade 3 = diffuse necrosis greater than 90% based upon whole transverse sections. Scintigraphically, we analyzed 201TI uptake before and after preoperative chemotherapy. The changes in the tumor-to-background ratio were defined by an alteration ratio. RESULTS: Of the 11 patients with a grade 1 response, the ratio showed -67.1% +/- 45.4% (mean +/- s.d.). Of the 9 patients with a grade 2 response, the ratio showed 37.9% +/- 29.9% of the 10 patients with a grade 3 response the ratio showed 105.5% +/- 12.4%. The ratios correlated well with the histologic grades (p < 0.0001; analysis of variance). CONCLUSION: Thallium-201 scintigraphy accurately assesses the effect of chemotherapy on osteosarcoma.

Analysis of metastatic spread and growth of tumor cells in mice with depressed natural killer activity by anti-asialo GM1 antibody or anticancer agents.

The mechanism of artificial and spontaneous metastases of tumor was analyzed in B16 melanoma cells and C57BL/6 mice by using anti-asialo GM1 antibody and anticancer agents. Single administrations of 500 micrograms anti-asialo GM1 antibody resulted in significantly decreased NK activity in spleen cells of C57BL/6 mice, lasting 10 days from the day following administration. Treatment with anti-asialo GM1 antibody never decreased the function of T lymphocytes measured by blastogenesis with phytohemagglutinin or T cell growth factor. The tumoricidal functions of activated macrophages but not of resident macrophages were decreased by in vivo treatment with anti-asialo GM1 antibody. The anti-asialo GM1 antibody was evaluated in terms of the enhancing effect on pulmonary metastases with regard to the timing of administration. Treatment with anti-asialo GM1 antibody 1 day before or on the day of tumor inoculation resulted in a substantial increase in the number of artificial pulmonary metastases. In the experimental system of spontaneous metastases, anti-asialo GM1 antibody most effectively increased the number of pulmonary metastases when administered 1-2 weeks before the removal of primary tumor, when the tumor cells are thought to be released into blood circulation from the primary site. In addition, accelerated growth of transplanted tumors at the primary site was observed in mice treated with anti-asialo GM1 antibody. These results strongly suggest that anti-asialo GM1 antibody enhances the incidence of in vivo tumor metastases and the growth of transplanted tumor mainly by suppressing the function of NK cells. The maximum effective dose (MED) of mitomycin C or its derivative (M-83) suppressed NK activity significantly, and pretreatment with these anticancer agents enhanced the growth of the artificial pulmonary and liver metastases. In contrast, the MED of cDDP showed no effect on the NK activity or the numbers of pulmonary and liver metastases. These results indicate that the depression of NK activity induced by chemotherapy results in the promotion of metastatic disease. From these studies it can be concluded that NK cells have a key role in the control of metastases of malignant disease, and that support of NK activity is very important for the prevention of metastases.

Charges on proteins and distances of electron transfer in metalloprotein redox reactions.

A modified form of the Debye-Marcus equation relating electron transfer rate constants to charges on proteins and distances of electron transfer has been applied to the reaction of chemically modified cytochrome f, in which positively charged amino groups are replaced with negatively charged carboxyl groups. The rate of electron transfer from reduced cytochrome f to ferricyanide decreased with increasing ionic strength when the native and singly substituted cytochrome f were used, although a sharp decrease was observed in the former case. When doubly or more than triply substituted cytochrome f was used, the rate of electron transfer was almost constant or increased with increasing ionic strength, respectively. The kinetic-ionic strength effects on this reaction can be well explained by the Debye-Marcus equation in which the charge and radius of the protein are treated as variable parameters. The results show the importance of local positive charges of about 2.0 on native cytochrome f and effective radius of about 11 A of cytochrome f for the electron transfer to ferricyanide. Since the net charge on the native cytochrome f is negative and the calculated radius of the protein is 22.8 A, the above results indicate that positive charges on the electron transfer site control the electrostatic interactions in this reaction. Previously reported data which had been analyzed by using the total net charge and full radius of the protein, were also well explained by the local charge and effective radius of the protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Human mucus protease inhibitor in airway fluids is a potential defensive compound against infection with influenza A and Sendai viruses.

Tryptase Clara, a trypsin-like protease localized exclusively in and secreted from Clara cells to the bronchial epithelium of rat, proteolytically activates the infectivity of influenza A virus [H. Kido, Y. Yokogoshi, K. Sakai, M. Tashiro, Y. Kishino, A. Fukutomi, and N. Katunuma (1992) J. Biol. Chem. 267, 13573-13579]. We report here that human mucus protease inhibitor (MPI), a major inhibitor of granulocyte elastase in the lining fluids of the human respiratory tract, significantly inhibited proteolytic activation of the infectivity of influenza A and Sendai viruses by tryptase Clara in vitro and multi-cycles of mouse-adapted influenza A virus replication in rat lungs in vitro. Recombinant MPI and the C- but not the N-terminal domain of the MPI inhibited both the proteolytic activity of tryptase Clara and the activation of virus infection. The 50% inhibitory concentrations of recombinant MPI and the C-terminal domain for tryptase Clara with Sendai virus envelope glycoprotein as substrate were 7.4 and 61.6 nM, respectively. These results indicate that MPI is a defensive compound against virus infection. Since there is evidence suggesting that concentrations of MPI in respiratory fluids are insufficient for prevention of virus infection, administration of MPI in the airway may be useful for treatment of these virus infections.

Prognostic relevance of rosette-like features in osteosarcoma.

AIMS: To clarify the prognostic relevance of rosette-like features and other clinicopathological and immunohistochemical variables in patients with osteosarcoma. METHODS: Clinicopathological and immunohistochemical variables were analysed in 131 patients with non-metastatic high grade conventional osteosarcoma, with particular attention to the prognostic impact of rosette-like features. RESULTS: Rosette-like features were present in 18 (14%) cases. Rosette-like features were significantly associated with the osteoblastic subtype, numerous osteoclast-like giant cells, moderate pleomorphism, frequent haemangiopericytoma-like vascular patterns, epithelioid cytological features, positive immunoreactivity for epithelial membrane antigen and CD56, and negative staining for cytokeratin. In a multivariate analysis, rosette-like features (relative risk (RR), 3.8), a poor chemotherapy effect (RR, 2.9), and a tumour size of 10 cm or more (RR, 2.8) were identified as unfavourable prognostic factors. CONCLUSIONS: Rosette-like features can easily be identified from routine histological slides and the relative risk in patients with non-metastatic, conventional osteosarcoma is as high as other well known prognostic factors, including large size and poor chemotherapy effect.

Osteosarcoma with cytokeratin expression: a clinicopathological study of six cases with an emphasis on differential diagnosis from metastatic cancer.

AIMS: To clarify the clinicopathological profile of osteosarcomas showing an intensely positive immunoreaction for cytokeratin. METHODS: Clinicopathological and immunohistochemical features were analysed in 131 patients with non-metastatic, conventional osteosarcoma, treated in Akita University and National Cancer Centre in Tokyo between 1972 and 1999. RESULTS: Six patients (4.5%; mean age, 32 years; four men, two women) had osteosarcomas showing intense cytokeratin expression. Tumours were located on the long bones of the extremities in five patients and the ilium in one. Osteoid formations were found in biopsied specimens in all cases. Three tumours were classified as osteoblastic osteosarcoma, two as fibroblastic, and one as chondroblastic. In three tumours classified as the osteoblastic subtype, epithelioid features were prominent, and four tumours showed pronounced cellular pleomorphism. In contrast to the expression of cytokeratin, epithelial membrane antigen was negative in all cases. Surgery with a wide excisional margin was performed in six patients. Preoperative and postoperative chemotherapy was given to five of the six patients, but the effects of these agents were negligible. Three of the six patients developed lung metastases, whereas the other three patients have remained well with no evidence of local recurrence or distant metastasis. CONCLUSIONS: Osteosarcoma with intense immunoreaction for cytokeratin was rare. The clinicopathological features were similar to those of patients with conventional osteosarcoma, except for a higher age, chemotherapy resistance, histological epithelioid features, and pleomorphism. This study indicates that osteoid formation and negative expression of epithelial membrane antigen are key features in the differentiation from metastatic carcinoma.

Prognostic significance of grading (MIB-1 system) in patients with myxoid liposarcoma.

AIMS: To determine the relation between clinical outcome and tumour grade defined by a MIB-1 (Ki-67) score based grading system. METHOD: The clinical and pathological features of 50 patients with myxoid liposarcoma were evaluated, and MIB-1 immunostaining was performed to grade these patients' tumours. Univariate and multivariate analyses were conducted to evaluate survival. Clinical follow up details were available for all patients (median, 46.5 months; range, 9-408). RESULTS: Univariate analysis revealed that the tumour site (p < 0.05), round cell component content (p < 0.01), necrosis (p < 0.01), mitosis (p < 0.01), MIB-1 labelling index (p < 0.001), and tumour grade (p < 0.001) had a significant impact on overall survival. Multivariate analysis showed that, of the variables evaluated, the tumour grade defined by a MIB-1 score based grading system was the most significant adverse prognostic factor. CONCLUSION: Tumour grade determined by the grading system using the MIB-1 score (MIB-1 system) is a very strong prognostic factor in patients with myxoid liposarcoma.

Low grade malignant peripheral nerve sheath tumour: varied cytological and histological patterns.

BACKGROUND: A small number of malignant peripheral nerve sheath tumours (MPNSTs) are low grade, and the nature of these low grade tumours has never been systematically assessed. AIMS: To describe the clinicopathological, immunohistochemical, and ultrastructural features of low grade MPNST and to discuss the main differential diagnoses. METHODS: Four cases of low grade MPNST were studied, including one coexistent with neurofibromatosis type 1. The tumours were analysed with respect to nuclear atypia, cellularity, nuclear enlargement, hyperchromasia, mitotic rate, and necrosis. Immunohistochemistry was performed by standard techniques, and an ultrastructural study was performed on one tumour. RESULTS: The ages of the patients ranged from 32 to 72 years (mean, 58). Two were male and two were female. Three tumours occurred in the deep tissue, including one in the retroperitoneum, and one was located in the dermal and subcutaneous tissue. The maximum diameters of the tumours ranged from 3.5 to 8.0 cm. Microscopically, all tumours showed moderate hypercellularity, an increased nuclear to cytoplasmic ratio, and hyperchromasia, but exhibited varied growth patterns, including those that were atypical neurofibroma-like, low grade fibromyxoid sarcoma-like, low grade epithelioid, and haemangiopericytoma-like. All tumours showed immunoreactivity for S-100 protein and vimentin. CONCLUSIONS: These findings suggest that careful clinical and histological evaluation, along with S-100 protein immunostaining, are essential for the accurate diagnosis of low grade MPNST.

Histamine release induced by human natriuretic peptide from rat peritoneal mast cells.

We have been interested in the effects of some popular peptides on tracheal smooth muscle. Previously, we reported that atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) had dose-dependent relaxant effects on guinea pig tracheal smooth muscle. In this study, we compared the effects of ANP, BNP and CNP on histamine release from rat peritoneal mast cells. ANP and BNP were more potent than CNP, dose-dependently increasing histamine release at a concentration of 10(-7) M or higher. CNP induced histamine release at a concentration of 10(-6) M or higher. Extracellular calcium inhibited the histamine release induced by all 3 peptides. In conclusion, the effects of these 3 peptides in rat peritoneal mast cells demonstrated adverse reactions for respiratory diseases, although our previous results showed that these peptides caused relaxation of guinea pig tracheal smooth muscle. We should note that the drugs have different actions in each organ.

Cellular proteases involved in the pathogenicity of enveloped animal viruses, human immunodeficiency virus, influenza virus A and Sendai virus.

In enveloped viruses, post-translational proteolytic activation is a critical step for the fusion activity and thus for the infectivity of the virus. In addition to the membrane receptors for the viruses, proteolytic activation is indispensable for effective virus spread in the infected host and it is a prime determinant for pathogenicity. Here we described the host cellular processing proteases, tryptase Clara and tryptase TL2, which proteolytically activate the infectivity of influenza A and Sendai viruses in the respiratory tract and HIV-1 in human CD4+ T cells, respectively. A novel trypsin-like protease, designated tryptase Clara, was purified from rat lung. The enzyme is localized in Clara cells of the bronchial epithelium and is secreted into the airway lumen. The enzyme specifically recognizes the consensus cleavage motif Gln(Glu)-X-Arg of influenza A and Sendai viruses and proteolytically activates the envelope fusion glycoproteins of the progeny viruses extracellularly in the airway lumen. Human mucus protease inhibitor and pulmonary surfactant in airway fluid inhibited the proteolytic activation of these viruses and also suppressed multiple cycles of viral replication in vitro. These results suggest that an imbalance between the amount of tryptase Clara and that of endogenous inhibitors in airway fluid is a prime determinant for pneumopathogenicity of the viruses. Therefore supplementing an endogenous inhibitor at therapeutic doses may protect against virus infection. In HIV-1 infection, binding of the gp120 envelope glycoprotein to the CD4 receptor is not sufficient in itself to allow virus entry, and an additional component(s) in the membrane is required for cell infection as a cofactor. We isolated a serine protease named tryptase TL2, in the membrane of CD4+ lymphocytes, which specifically binds to the V3 loop of HIV-1 gp120 as a cofactor. After binding, tryptase TL2 proteolytically processed gp120 into two protein species of 70 and 50 kDa and the cleavage was suppressed by a neutralizing antibody against the V3 loop. The amino acids that constitute the cleavage sites in the V3 loop of almost all HIV isolates are variable, but they are restricted to those which are susceptible to chymotryptic and/or tryptic enzyme. The multi-substrate specificity of tryptase TL2, which has tryptic and chymotryptic specificities, may correspond tot he variability of the V3 loop. The selective cleavage of the V3 loop by tryptase TL2 may lead to a conformational change of gp120, resulting in the dissociation of gp120 from gp41, exposing the fusogenic domain of the transmembrane protein gp41 following virus-host cell fusion.

Color tuning mechanism of human red and green visual pigments.

We investigated the molecular mechanism of a rather large red shift of 31 nm in a human red pigment compared with a human green pigment. In this analysis, we paid special attention to the phenomenon of nonadditivity of spectral shifts due to substitution of the key amino acids (OH-bearing amino acids) and the phenomenon of cooperativity by which the spectral shifts due to substitution of the key amino acids in the protein environment of red pigment are about 1.5 times larger than that in the protein environment of green pigment. The analysis was made by using a model of three active sites on which the key amino acids are located and four effective sites by which the effect of the key amino acids is modified. As a result, we found that the interaction between the active sites that occurs through the repolarization of the chromophore induced by the key amino acid is essential for the nonadditivity phenomenon. We also found that the interaction between the active site and the effective site plays a major role in the cooperativity phenomenon. More directly, we say that the highly polarizable property of the chromophore is the origin of the rather large red shift in red pigment. Based on these analyses, we conclude that the interaction between the polarizable chromophore and the protein moiety has the capability of producing a significant spectral shift, at least 1000 cm-1, even by substitution of moderate polar residues of the OH-bearing amino acids.

A malignant peripheral nerve-sheath tumour responding to chemotherapy.

A malignant peripheral nerve-sheath tumour developed in the right S1 nerve root in a man aged 30 causing back pain and sciatica. CT and MRI revealed a destructive tumour of the sacrum invading the retroperitoneal space. The tumour was not resectable with an adequate margin. Chemotherapy, consisting of high-dose ifosfamide followed by a combination of vincristine, doxorubicin and cyclophosphamide, was given with success. Malignant peripheral nerve-sheath tumours are thought to respond weakly to chemotherapy, but the response in our patient was complete.

On clinical usefulness of Tl-201 scintigraphy for the management of malignant soft tissue tumors.

The purpose of this study was to investigate Tl-201 as a tumor scanning agent in patients with malignant soft tissue sarcomas and to establish the sensitivity of this type of scintigraphy concerning local recurrences or metastases that may remain clinically suspected. Seventy-eight patients with malignant soft tissue sarcomas and 22 with benign soft tissue tumors were studied. Of these 78 malignant soft tissue sarcomas patients, the sensitivity of Tl-201 (81.2%) was higher than that of Ga-67 (68.8%). Thirty-three out of 78 patients received a total of 95 consecutive scintigraphic follow-up examinations. Therapeutic effects was assessed by comparing the results of Tl-201 examinations with the clinical findings. Of these 33 patients, the therapeutic effects observed were as follows: complete remission 1, partial remission 8, progress of disease 1, and no remarkable change 23. Tl-201 scintigraphy has proved itself very useful not only in clinically detecting the malignant soft tissue sarcomas and in assessing therapeutic effects on these diseases, but also in assessing the follow-up patients with malignant soft tissue sarcomas.

Comparison of Tc-99m pertechnetate with Tl-201 and Ga-67 scintigraphy of malignant soft-tissue tumors.

Tc-99m pertechnetate scintigraphy was compared with Tl-201 chloride and Ga-67 citrate to evaluate the avidity of Tc-99m pertechtate for malignant soft-tissue tumors. Twenty-three patients with malignant soft-tissue tumors underwent scintigraphic studies. All 23 received Tc-99m and Tl-201, whereas 14 also were injected with Ga-67. In 21 (91%) of the 23 patients, Tc-99m accumulated extensively in the tumors. Tl-201 accumulated in 12 (52%) of the 23 tumors. Ga-67 accumulated in only 5 (36%) of the 14 tumors. The avidity of Tc-99m for myxoid tumors was markedly different from the other two agents. Tc-99m accumulated in all eight myxoid tumors, while neither Tl-201 or Ga-67 showed marked accumulation except for one patient with increased accumulation of Tl-201. This study shows that Tc-99m pertechnetate has the potential to localize malignant soft-tissue tumors and may be useful in the evaluation of these tumors.

[Preoperative systemic chemotherapy of patients with osteosarcoma: a preliminary study of nine cases].

Nine patients with osteosarcoma were treated with cisplatinum and high-dose methotrexate therapy. According to the clinical responses to each drug, we selected and used the effective one with adriamycin or bleomycin, cyclophosphamide and actinomycin-D combination therapy. We treated patients with these protocols for several months (two and one-half to eight months). Both high-dose methotrexate and cisplatinum were effective in two cases, methotrexate or cisplatinum was effective in two patients individually (both resistant), but ifosfamide was effective in one case. No differences between any drug in the pattern of effective drug response. It is possible to exclude non-effective drugs from the preoperative schedule according to the degree of clinical responses manifested within one or two weeks. This preliminary study suggested that intensive systemic preoperative chemotherapy will control primary and micrometastatic lesions of osteosarcoma and improve the treatment for primary and advanced osteosarcoma.

[Adjuvant chemotherapy in the treatment of primary soft tissue sarcomas, with special reference to intra-arterial infusion chemotherapy].

Seventy-eight cases of adjuvant chemotherapy for primary soft tissue sarcoma including 51 cases of intra-arterial infusion chemotherapy were studied. The patients ranged in age from 1 to 92 years with a median age of 34 years. Thirty-nine patients were male and 39 were female. The seventy-eight cases were comprized of 17 rhabdomyosarcoma, 12 liposarcoma, 12 neurogenic sarcoma, 10 malignant fibrous histiocytoma, 8 leiomyosarcoma, 7 angiosarcoma, 8 others and 4 unclassified sarcomas. Fifty-one patients with soft tissue sarcoma of the extremities were treated by intra-arterial infusion chemotherapy with either VCQ (Vincristine and Carbazilquinone) or VCQ, A (Vincristine, Carbazilquinone and Adriamycin). Out of 42 patients with measurable lesions, 2 CR, 4 PR, 33 NC and 3 PD were obtained. Histological examinations demonstrated histological effect of GI 19, G IIa 11 and G IIb 7 by Ohboshi and Shimosato's criteria. Remarkable effects of treatment were noted in most rhabdomyosarcoma patients. After intra-arterial infusion chemotherapy, a variety of surgical procedures ranging from marginal resection and wide resection to radical amputation were employed in 44 patients. Local recurrence was 27% and distant metastasis developed in 47% of cases.

[TNM classification of bone and soft tissue sarcomas].

TNM classification of bone and soft tissue sarcomas was published by UICC in 1987. Histological grading (G) is an important factor in this classification, but the criteria of G categories are not so clear. In addition, lymph node metastasis is very rare in bone and soft tissue sarcoma. Therefore, prognostic factors are limited to T, M and G categories. Since correlation between the stage (UICC) and the survival rate was not found in patients with osteosarcoma, TNM classification (UICC) has not been used widely in the field of orthopedic oncology. The Musculoskeletal Tumor Committee of the Japanese Orthopaedic Association proposed another TNM classification of osteosarcoma based on multivariate analysis. T1 is less than 15 cm and T2 is 15 cm or larger in maximal diameter. N and M are same with the UICC criteria. Serum alkaline phosphatase level (A) is included in this classification in which A0 is less than the normal value x2.5, and A1 is the normal value x2.5 or more. G categories are separated into two groups according to the mitotic rate in a high power field (x200); G1 is assigned to the tumor with 0-9/1 HPF and G2 is assigned to those with 10 or more/1 HPF. Reclassification of osteosar-coma by this modified TNM system indicated that there was a correlation between the survival rate and the stage.

[Treatment of rhabdomyosarcoma at the National Cancer Center Hospital].

Seventy-nine patients with rhabdomyosarcoma (RMS) received treatment at the National Cancer Center Hospital between 1962 and 1985. The patients ranged in age from 4 months to 74 years with a median age of 6 years. Forty-six patients were male and 33 were female. The primary tumor site of RMS was the same as in the previous report. The head and neck region was the most frequent site (40.5%), followed by the extremities (34.1%), genitourinary region (15.2%), trunk (5.1%) and retroperitoneum (5.1%). Histologic types were embryonal RMS in 45 patients, alveolar RMS in 23 patients, pleomorphic RMS in 8 patients and unclassified RMS in 3 patients. As of October 1985, 14 of the 79 patients were still alive. Between 1962 and 1971, 38 patients were not treated by any protocol. After 1972, 41 patients received treatment using a 3 stage-related, multiple-modality program. In the first protocol, chemotherapy consisted of Vincristine, Cyclophosphamide, and Actinomycin-D, and 1 of 18 patients have survived more than 5 years. The cumulative 5-year survival rate of the first protocol was 11.1%. In the second treatment program, which involved Adriamycin in addition to the 3 drugs cited above, 4 of 23 patients have survived more than 5 years. The cumulative 5-year survival rate, 33.2%, was very improved.

[Diagnosis and treatment of metastatic bone cancer of the extremities].

Eight hundred and thirty-six patients with metastatic cancer in the bone excluding autopsy findings, occurring between January, 1976 and December, 1985 were reviewed. The most frequent site of primary focus was the breast (33.2%), followed by lung (24.6%). Three hundred and forty-two patients (40.9%) were male and 494 (59.1%) female. Diagnosis of bone metastasis was based on abnormal accumulation in the bone scintigram and abnormal findings in the bone X-ray at the same site. Out of 836 patients, 285 had metastatic skeletal lesion including extremities and 43 had a solitary lesion of the extremity. The most frequent site of bone metastases in the extremity was proximal femur and involvement of the femur was 65.2% and that of humerus was 25.6%. The majority of the patients were treated by irradiation (24.9%), irradiation with chemotherapy and/or hormone therapy (21.1%), chemotherapy (18.6%) and chemotherapy with hormone therapy (17.2%), on the other hand, only 25(8.8%) of 285 patients were treated by surgical procedures. Cumulative survival rate after diagnosis of bone metastasis varied with site of primary focus and 5 year survival rate of all cases was 6.1%. Clinical courses after skeletal metastasis were separated into two types, and one type was breast type which was slow and other type was lung type which was rapid. The most important factor for the prognosis of the patients with bone metastasis is thought to be the primary site of origin.