Multidrug resistance and malignancy in human osteosarcoma.

In osteosarcoma, resistance to chemotherapy and metastatic spread are the most important mechanisms responsible for the failure of current multimodal therapeutic programs. We have shown previously that overexpression of the MDR1 gene product P-glycoprotein is the most important predictor of an adverse clinical course in patients with osteosarcoma. treated with chemotherapy. In this study, we analyzed the relationship between P-glycoprotein expression and local aggressiveness and systemic dissemination of multidrug-resistant (MDR) human osteosarcoma cells. Compared to parental sensitive cells, MDR cells showed a decreased tumorigenicity,and metastatic ability in athymic mice, together with a reduced migratory and invasive ability and a lower homotypic adhesion ability in vitro, suggesting that P-glycoprotein overexpression is associated with a less malignant phenotype. These experimental observations were confirmed by clinical data. In fact, the time of appearance of lung metastases in a series of osteosarcoma patients treated with chemotherapy was significantly shorter in the group of cases with no expression of P-glycoprotein in the primary lesion compared to the group with P-glycoprotein overexpression. Moreover, the incidence of P-glycoprotein overexpression was found to be higher among patients with localized disease at the clinical onset than in patients with evidence of metastasis at the time of diagnosis. These data indicate that, in osteosarcoma, the MDR phenotype is not associated with a more aggressive behavior both in vitro and in clinical settings, suggesting that the previously shown association of the MDR phenotype with a worse outcome in osteosarcoma is not related to a higher metastatic ability of cells with P-glycoprotein overexpression but is more likely due to their lack of responsiveness to cytotoxic drugs.

The Met/HGF receptor is over-expressed in human osteosarcomas and is activated by either a paracrine or an autocrine circuit.

The c-MET oncogene encodes the receptor for the Hepatocyte Growth Factor/Scatter Factor (HGF), a cytokine that stimulates the invasive growth of normal and neoplastic cells. The Met/HGF receptor is expressed by epithelial cells and its ligand by cells of mesenchymal origin. Receptor-ligand interaction occurs via a paracrine circuit. We studied the expression of the Met/HGF receptor and of its ligand in mesenchymal human tumours by examining 39 clinical samples of bone tumours. The Met/HGF receptor was not detectable in the majority of bone tumours, as expected from their mesenchymal origin. Notably, the receptor was overexpressed in 60% of the osteosarcomas examined. In 12 osteosarcoma cell lines the Met/HGF receptor was overexpressed, phosphorylated by HGF stimulation and fully functional. HGF was detected in two out of seven clinical specimens of osteosarcoma. The ligand and the receptor are co-expressed in two clonal osteosarcoma cell lines. In these lines the Met/HGF receptor was constitutively phosphorylated; phosphorylation was suppressed by suramin treatment, a known blocker of autocrine loops. These data suggest that activation of the Met/HGF receptor by a paracrine or an autocrine mechanism might play a role in the particularly aggressive behaviour of osteosarcomas.

The expression of P-glycoprotein is causally related to a less aggressive phenotype in human osteosarcoma cells.

The relationship between P-glycoprotein expression and malignancy is controversial. We have recently found that, in osteosarcoma, multidrug resistance (MDR) is associated with a less aggressive behavior, both in vitro and in clinical settings. In this study, we evaluated whether P-glycoprotein overexpression has a cause-effect relationship with the reduced metastatic potential of MDR cells, or rather reflects a more complex phenotype. MDR1 gene-transfected osteosarcoma cell clones, showing different levels of P-glycoprotein expression, were analysed for their in vitro characteristics and their tumorigenic and metastatic ability in athymic mice. Apart from the different levels of P-glycoprotein, no significant change in the expression of surface antigens or in the differentiative features were observed in the MDR1 gene transfectants compared to the parental cell lines or control clones, obtained by transfection with neo gene alone. In contrast to controls, however, MDR1 transfectants showed a significantly lower ability to grow in semi-solid medium and were completely unable to grow and give lung metastases in athymic mice. These findings indicate that P-glycoprotein overexpression is causally associated with a low malignant potential of osteosarcoma cells, and open new insights on the role and functions of P-glycoprotein activity.

Relationship of chemotherapy-induced necrosis and surgical margins to local recurrence in osteosarcoma.

PURPOSE AND METHODS: To assess patients with high-grade osteosarcoma treated at our institution for various prognostic factors for the development of local recurrence of disease. Follow-up data were available for all patients and the mean follow-up duration was 65 months in surviving patients. RESULTS: There were 28 local recurrences in this study (7%). Of these, only three patients (11%) were alive at the most recent follow-up point, 28, 53, and 54 months after local recurrence. None of 59 patients who were treated primarily with a radical amputation and none of 10 who underwent a rotationplasty developed local recurrence. Four of 48 patients (8%) who had wide amputations, one of whom had an intralesional amputation, and 23 of 237 (10%) who had limb-salvage surgery developed locally recurrent disease. Of 237 patients who underwent limb-sparing resection, three prognostic factors for local control were identified. The strongest association with local recurrence was chemotherapy response (P < .0001), followed closely by surgical margins (P = .0001). Older patients were more likely to have locally recurrent disease (P = .033), with each decade of life older than the first decade having a relative risk of 1.5 times greater per decade (SE = 0.16; 95% confidence interval, 0.034 to .0650). Factors that were not associated with local recurrence included sex, date of diagnosis, and anatomic site of disease. CONCLUSION: Chemotherapy-induced tumor necrosis and surgical margins are important prognostic factors for local control of patients with osteosarcoma.

Predictive factors of histologic response to primary chemotherapy in osteosarcoma of the extremity: study of 272 patients preoperatively treated with high-dose methotrexate, doxorubicin, and cisplatin.

PURPOSE: In osteosarcoma of the extremity, a strong correlation between chemotherapy-induced necrosis and prognosis has been reported. The aim of this study was to investigate the possible factors that influence histologic response to primary chemotherapy. PATIENTS AND METHODS: In 272 patients with high-grade osteosarcoma of the extremity preoperatively treated with high-dose methotrexate (HDMTX), cisplatin (CDP), and doxorubicin (ADM), the histologic response to chemotherapy was evaluated and graded as complete (no viable tumor cells) or incomplete (persistence of viable tumor cells). Several factors, such as metastatic disease to the lung at diagnosis, sex, age, site and tumor volume, histologic subtype, serum alkaline phosphatase, lactate dehydrogenase (LDH), and methotrexate (MTX) pharmacokinetics were investigated to test their predictive significance on histologic response. RESULTS: Fifty-one patients with localized disease (20.6%) and none of the 25 patients with metastatic disease at presentation had a complete histologic response (P = .006). After multivariate analysis, performed on patients with localized disease only, MTX serum peak (> or = 700 micromol/L) and histologic subtype were proven to be significant predictive factors of histologic response. A complete response was seen in 28.8% of patients with 700 micromol/L or greater MTX serum levels and in 9.9% of those patients with lower levels (P = .001). The chondroblastic subtype was less responsive (6.1% of complete response), compared with the osteoblastic (16.3%), fibroblastic (33.3%), and telangiectatic (42.3%). CONCLUSION: Patients with metastatic osteosarcoma and localized chondroblastic osteosarcoma have a reduced chemosensitivity to primary chemotherapy with MTX, CDP, and ADM. MTX serum peak significantly influences tumor necrosis. A dose adaptation of MTX is recommended to obtain a serum peak of 700 micromol/L or greater when MTX is infused in 6 hours.

Long-term outcome for patients with nonmetastatic osteosarcoma of the extremity treated at the istituto ortopedico rizzoli according to the istituto ortopedico rizzoli/osteosarcoma-2 protocol: an updated report.

PURPOSE: To provide an estimate of long-term prognosis for patients with osteosarcoma of the extremity treated in a single institution with neoadjuvant chemotherapy and observed for at least 10 years. PATIENTS AND METHODS: Patients with nonmetastatic osteosarcoma of the extremity were preoperatively treated with high-dose methotrexate, cisplatin, and doxorubicin (ADM). Postoperatively, good responders (90% or more tumor necrosis) received the same three drugs used before surgery, whereas poor responders (less than 90% tumor necrosis) received ifosfamide and etoposide in addition to those three drugs. RESULTS: For the 164 patients who entered the study between September 1986 and December 1989, surgery was a limb salvage in 136 cases (82%) and a good histologic response was observed in 117 patients (71%). At a follow-up ranging from 10 to 13 years (median, 11.5 years), 101 patients (61%) remained continuously free of disease, 61 relapsed, and two died of ADM-induced cardiotoxicity. There were no differences in prognosis between good and poor responding patients. ADM-induced cardiotoxicity (six patients), male infertility (10 of the 12 assessable patients), and second malignancies (seven patients) were the major complications of chemotherapy. Despite the large number of limb salvages performed, only four local recurrences (2.4%) were registered. CONCLUSION: With an aggressive neoadjuvant chemotherapy, it is possible to cure more than 60% of patients with nonmetastatic osteosarcoma of the extremity and amputation may be avoided in more than 80% of them. Because local or systemic relapses, myocardiopathies, and second malignancies are possible even 5 years or more after the beginning of treatment, a long-term follow-up is recommended for these patients.

Analysis of P-glycoprotein expression in osteosarcoma.

Current treatment of high-grade osteosarcoma combines surgical removal of the lesion with chemotherapy. In this study we evaluated whether the expression of P-glycoprotein, a protein closely associated with multidrug resistance, may be helpful in identifying the patients whose tumours will be further resistant to specific agents. By using multidrug-resistant osteosarcoma cell lines as standards, the expression of P-glycoprotein was evaluated in 105 cases of primary and metastatic osteosarcoma by semiquantitative immunofluorescence. Overexpression of the protein was shown in 23% of primary and in 50% of metastatic lesions. In 38 cases, homogeneously treated and followed-up for at least 24 months, overexpression of P-glycoprotein appeared to be associated with a higher relapse rate and with a trend toward a worse outcome. These data support the role of P-glycoprotein in the response to chemotherapy and its involvement in the determination of the outcome of osteosarcoma patients.

Adamantinoma of the long bones. The experience at the Istituto Ortopedico Rizzoli.

All cases of adamantinoma seen at the Istituto Ortopedico Rizzoli were retrospectively reviewed. Although this tumor is exceedingly rare, nine cases were collected. The tumor is composed of four histological patterns: spindle, basaloid, squamoid, and tubular. The prognosis of this tumor depends on the adequacy of therapy. Surgery that is expedient and adequate tends to offer the best prognosis.

Absence of stimulatory effect of g-csf on the growth of human sarcoma-cells.

The Colony-Stimulating Factors (CSFs) are undergoing clinical trials for their ability to stimulate the regeneration of bone marrow in patients receiving anticancer chemotherapy. However, the reported effects on the growth of tumor cell lines of different derivations, including osteosarcoma, raise the possibility that the use of these cytokines may induce proliferative effects also in residual tumor cells. In this study, we have used a panel of 12 human osteosarcoma (2 cell lines and 10 primary cultures) and 7 Ewing's sarcoma cell lines (5 cell lines and 2 primary cultures) to evaluate the presence of the G-CSF receptor by RT-PCR and the effects of recombinant Human (rHu) G-CSF on their in vitro growth ability. RT-PCR did not reveal the presence of G-CSF receptor band in any of the osteosarcoma or Ewing's cell lines examined. Moreover, after exposure to rHuG-CSF, no significant stimulatory or inhibitory effects were observed in any of the cell lines. Therefore, G-CSF may be safely used to stimulate marrow regeneration after high-dose chemotherapy both in osteosarcoma and in Ewing's sarcoma.

Evaluation of osteonectin as a diagnostic marker of osteogenic bone tumors.

Osteonectin (ON), a 32,000-kd glycoprotein involved in the early steps of mineralization of skeletal tissue, is a recognized differentiation marker of normal osteogenic cells. The expression of ON was evaluated in vitro and in tissue sections by the polyclonal antibody bON II. In different cell cultures immunocytochemistry and molecular biology displayed a nonspecific reaction for the antibody, which showed itself to be useless for the in vitro identification of cells of the osteoblastic lineage. The diagnostic use of bON II antibody was investigated by immunohistochemistry on a series of osteogenic and nonosteogenic bone tumors. A strongly positive stain of the entire neoplastic component of osteosarcoma and osteoblastoma and a weaker stain of the mononuclear component of giant cell tumor and chondroblastoma were observed. On the other hand, stains for chondrosarcoma, Ewing's sarcoma, fibrosarcoma, malignant fibrous histiocytoma, and brown tumor from hyperparathyroidism were entirely negative. Our results indicate that ON may be helpful in the histologic diagnosis of bone tumors, particularly in differentiating small cell osteosarcoma from other small round cell tumors.

Adriamycin binding assay: a valuable chemosensitivity test in human osteosarcoma.

The reliability of a simple method evaluating the pattern of subcellular binding of Adriamycin (Adriamycin binding assay, ABA) as an index of sensitivity was demonstrated in different primary cultures and in sensitive and resistant cell lines of human osteosarcoma. After exposure to Adriamycin (10 micrograms/ml for 30 min at 37 degrees C), living sensitive cells showed selective intranuclear uptake of the drug, whereas in resistant cells no distinct subcellular distribution was observed. The binding pattern of Adriamycin in sensitive and in highly resistant cells was inversely related to the expression of P-glycoprotein. However, low levels of resistance in vitro, not detectable by increased levels of expression of P-glycoprotein, were revealed by ABA. The use of ABA in combination with the estimate of P-glycoprotein expression is recommended in clinical practice as an accurate means for predicting the sensitivity of osteosarcoma to Adriamycin.

Giant-cell tumor and chondrosarcomas: grading, treatment and results (studies of 209 and 131 cases).

The Author reviews 209 cases of giant-cell tumor (follow-up 3-42 years in 130 cases) and 131 chondrosarcomas (70 central, 50 peripheral, 11 periosteal; follow-up 10-32 years in 63 cases). Giant-cell tumors are graded into three radiographic types (calm, active, aggressive) and three histologic types (typical, aggressive, sarcoma). Chondrosarcomas were also graded into three radiographic and three histologic types (grades I, II, III). Incidence and mutual relationships of radiographic and histologic grades are presented. In recurrences it is possible to observe a progression of malignancy in giant-cell tumor and - more often - in chondrosarcomas. Results are related to the radiographic and histologic grading and to the type of treatment. Indications for treatment are given according to the experience gained from this study. The Author enumerates the surgical techniques he has found most suitable for the conservative treatment of these tumors when resection is indicated.

P-glycoprotein expression in osteosarcoma: a basis for risk-adapted adjuvant chemotherapy.

Previous reports on osteosarcomas treated with multi-agent chemotherapy have shown that P-glycoprotein expression is a reliable prognostic indicator. The current thinking is that, of the several agents used for the treatment of osteosarcoma, only doxorubicin is involved in drug resistance mediated by P-glycoprotein. This study examines the relationship of P-glycoprotein expression to clinical outcome in osteosarcomas, treated only with doxorubicin in addition to surgery, to determine if the prognostic significance of P-glycoprotein expression reflects the ability of osteosarcoma to respond to this drug. The expression of P-glycoprotein in tumor specimens was assessed by immunohistochemistry in 37 nonmetastatic, operable osteosarcomas treated at a single institution with doxorubicin as a single adjuvant drug. The P-glycoprotein status was analysed in relation to the length of event-free survival. A widespread pattern of P-glycoprotein expression in tumor cells at diagnosis was significantly associated with a higher rate of systemic relapse (p < 0.001). On comparison of this group of patients with a similar series of 92 patients, all treated with multi-agent chemotherapy plus surgery of the primary lesion and previously analysed for P-glycoprotein status, only P-glycoprotein-positive, doxorubicin-resistant tumors consistently benefited from the addition of drugs other than doxorubicin (p < 0.001). Osteosarcomas with different abilities to respond to adjuvant chemotherapy can be identified by the expression of P-glycoprotein in tumor cells at the clinical onset. P-glycoprotein status may serve as a basis for risk-adapted, individualized therapeutic regimens. Standard programs are sufficient for P-glycoprotein-negative osteosarcomas, whereas P-glycoprotein-positive tumors may benefit from the use of more intensive therapeutic approaches.

Neoadjuvant chemotherapy for osteosarcoma of the extremity in patients in the fourth and fifth decade of life.

From January 1986 to March 1993, 29 patients aged between 40 and 60 years with primary high grade osteosarcoma of the extremity were treated at Rizzoli Institute with neoadjuvant chemotherapy. Before surgery patients received cisplatin and adriamycin. Postoperatively, patients with a good histologic response received the same two drugs preoperatively used, while in case of poor response ifosfamide and etoposide were added to cisplatin and adriamycin. Twenty-five patients (86%) were surgically treated with a limb salvage, whereas 4 patients (14%) were amputated. With a median follow-up of 8 years (5-12), the 8-year event-free survival was 57% and the 8-year overall survival was 62%. No chemotherapy-related deaths were recorded and toxicity was manageable. These results are significantly better than those achieved in 24 patients of the same age, treated at Rizzoli Institute between 1975 and 1985 only with surgery (87% of amputation and 17% of 8-year event-free and overall survival) and indicate an advantage for the use of neo-adjuvant chemotherapy also in patients with high grade osteosarcoma of the extremity older than 40 years.

Induction of HLA class II antigens in osteosarcoma cells by interferons and tumor necrosis factor alpha.

In this study we have evaluated the ability of interferons (IFNs) alpha, beta, gamma and Tumor Necrosis Factor (TNF) alpha to modulate the expression of the Major Histocompatibility Complex (MHC) antigens in human osteosarcoma cells. The osteosarcoma cell lines Saos-2 and U-2 OS, treated in vitro with IFNs and TNF alpha, showed an increased expression of class I HLA antigens. However, only IFN gamma and, to a lower extent, IFN beta induced the expression of class II HLA antigens. These effects were dose and time-dependent. Simultaneous treatment with IFN gamma and IFN beta or TNF alpha, which by itself was unable to induce the expression of class II HLA antigens, produced different effects on the two osteosarcoma cell lines: in Saos-2 IFN beta and TNF alpha amplified the effects obtained with IFN gamma alone; in U-2 OS, TNF alpha increased the expression induced by IFN gamma on class II HLA antigens, whereas IFN beta antagonized the effects of IFN gamma. IFN alpha did not influence the induction of class II HLA antigens by IFN gamma in the two osteosarcoma cell lines. IFNs have been introduced in some clinical protocols for the treatment of osteosarcoma, based on their antiproliferative activity. Our findings may contribute to a better knowledge of the effects of IFNs and TNF alpha in osteosarcoma by showing the existence of more complex interactions.

Osteofibrous dysplasia of the tibia and fibula.

Osteofibrous dysplasia of the tibia and fibula is not a well recognized entity. We have seen thirty-five patients with the disease. Twenty-two comparable cases have been reported in the literature with such diagnoses as ossifying fibroma, congenital fibrous dysplasia, and congenital fibrous defect of the tibia. The main differential diagnosis is with fibrous dysplasia and with adamantinoma of a long bone. Twelve of our patients had long-term follow-up and some of the lesions regressed spontaneously. Osteofibrous dysplasia seldom has even a moderate tendency to progress during childhood, but it recurs frequently after curettage or subperiosteal resection. Such recurrences generally are moderately progressive or not progressive at all. Any progression of the lesion comes to an end after puberty. Attempts at radical surgery either primarily or after recurrence do not seem to be necessary. Surgery should be delayed as long as possible and should be restricted to extensive lesions. The results of surgical treatment usually are good even in patients with a recurrence, fracture, or pseudarthrosis.

Periosteal chondroma. A review of twenty cases.

We are reporting on the cases of twenty patients with periosteal chondroma to stress the importance of a proper clinical and radiographic diagnosis of this lesion. Awareness of the features of the lesion helps to prevent overtreatment of this benign condition, because the cytological findings may be ominous. Even the radiographic pattern may be suggestive of malignant disease. Periosteal chondromas apparently arise from under the periosteum of the diaphysis or metaphysis in adolescents and young adults. Close cooperation between the surgeon, the radiologist, and the pathologist is necessary to achieve proper diagnosis and treatment. Marginal excision is usually effective treatment.

Chondrosarcoma of bone. The experience at the Istituto Ortopedico Rizzoli.

We retrospectively reviewed the records of 125 patients with chondrosarcoma seen at the Istituto Ortopedico Rizzoli. All of the patients had been followed for at least five years, and ninety-six patients had been followed for at least ten years. The requirements for the adequacy of treatment were carefully defined. Metastasis and survival were related to the histological grade of the tumor. Nine per cent of the grade-1 lesions and 44 per cent of the grade-3 lesions metastasized. Ninety-four per cent of the patients with grade-1 lesions survived for five years, compared with only 44 per cent of patients with grade-3 lesions. The ten-year survival rates were 87 per cent and 27 per cent, respectively. Adequacy of treatment had an important influence on the incidence of recurrence, length of survival, and length of disease-free survival. The incidence of recurrence in adequately treated patients was 6 per cent, but in inadequately treated patients it was 69 per cent. The five-year survival rates in these two groups were 81 per cent and 53 per cent, respectively. Seventy-eight per cent of the adequately treated patients were disease-free at follow-up (mean, 11.1 years) compared with only 6 per cent of the inadequately treated patients. We compared the results of this review with those of other reviews of chondrosarcoma.

Giant-cell tumor of bone.

Of 327 patients who had a giant-cell tumor of bone and were seen at the Istituto Rizzoli, 293 were treated at the Institute, and 280 of these were followed for two to forty-four years. The distribution according to sex and age of the patient and site of the tumor was similar to the distributions in major reports of large series. The tumor usually involved the metaphysis and the epiphysis, but was occasionally limited to the metaphysis, and in only 2 per cent of the patients was it adjacent to an open growth plate. The tumor on occasion invaded the articular space, also involving the ligaments and the synovial membrane. Extension to an adjacent bone through the joint occurred in 5 per cent of the tumors. Our radiographic grading, which is roughly comparable with the staging system of Enneking et al., was Grade I in 4 per cent, II in 74 per cent, and III in 22 per cent of 266 patients before treatment. A pathological fracture was apparent on the first radiograph in 9 per cent of the patients. In the 280 patients with adequate follow-up, 331 surgical procedures were performed. The rate of local recurrence was 27 per cent in the 151 intralesional procedures, 8 per cent in the 122 marginal excisions, and zero in the fifty-eight wide or radical procedures. These results did not correlate with the radiographic grade of the lesion. Of the fifty-one local recurrences that were seen after treatment at our institution, 90 per cent appeared in the first three years after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Chondroblastoma. A review of seventy cases.

We reviewed the cases of seventy patients with chondroblastoma who were treated at the Istituto Ortopedico Rizzoli between 1949 and 1983 and found that the proximal end of the humerus was the most common location (eighteen), with the proximal end of the femur (fifteen), distal end of the femur (fifteen), and proximal end of the tibia (twelve) being the other frequently involved sites. Sixty-three of the patients were between eleven and thirty years old. Fifty-eight patients sought medical attention because of an aching pain, usually referred to the adjacent joint. Fifty patients were followed for two years or longer after treatment. Seven patients had a local recurrence: four were successfully treated with a repeat curettage and one, by two subsequent marginal excisions; one was advised to have a repeat curettage; and the seventh was advised to have a resection and arthrodesis of the knee. The final functional results were considered to be excellent in forty-seven of the fifty patients who were followed for two years or more.