Messenger RNA Expression Levels of CXCR4 Correlate with Metastatic Behavior and Outcome in Patients with Osteosarcoma

PURPOSE

To determine if osteosarcoma cells express chemokine receptors and if their presence or absence relates to clinical features.

EXPERIMENTAL DESIGN

Using fluorescent quantitative real-time PCR, the pattern of 17 chemokine receptors in 3 osteosarcoma cell lines and 68 osteosarcoma patient samples was analyzed.

RESULTS

The expression of the chemokine receptors was generally low among the cell lines. In the high-grade osteosarcoma patient samples (n = 47), CXCR4 was the most commonly expressed (63%) and its expression level was inversely correlated to overall survival (P < 0.0001), event-free survival (P < 0.001), and metastasis-free survival (MFS; P = 0.002). There was also a correlation between the expression level of CXCR4 and the presence of metastasis at diagnosis (P = 0.002). CCR7 was expressed in 43% of the samples and its expression level was inversely correlated with overall survival (P = 0.03) and MFS (P = 0.007). CCR10 mRNA expression level was inversely correlated with MFS (P = 0.009). There was no association between the expression of CXCR4, CCR7, and CCR10. Of the 26 samples studied for stromal cell-derived factor-1 expression, 77% expressed it, but there was no correlation with the clinical variables or CXCR4 expression. Multivariate analysis revealed that mRNA expression level of CXCR4 was the only significant variable for overall survival (P = 0.0006), event-free survival (P = 0.004), and MFS (P = 0.025).

CONCLUSIONS

These data suggest that CXCR4 could be useful as a prognostic factor and as a predictor of potential metastatic development in osteosarcoma. If further studies confirm that it is relevant to metastases in this disease, it could represent a new therapeutic target.

Advances that are changing the diagnosis and treatment of malignant bone tumors

PURPOSE OF REVIEW

Several neoplastic conditions may affect bone. These include primary bone tumors as well as metastatic disease from distant primary sites. Often, these entities produce symptoms that may be difficult to distinguish from those of various rheumatologic entities. The purpose of this review is to discuss recent developments in orthopedic oncology, with special attention given to advances that are changing the diagnosis and treatment of bone sarcomas and carcinomas metastatic to bone.

RECENT FINDINGS

Much effort in the field of musculoskeletal oncology has been dedicated to the elucidation of the molecular mechanisms underlying bone sarcomas, especially in the case of osteogenic sarcoma and Ewing family tumor. Telomere maintenance mechanisms are emerging as potential targets for anticancer therapy. The most exciting advances have been in the development of novel treatments for cancers affecting bone. The anticancer effects of bisphosphonates, cyclooxygenase-2 inhibitors, and statins may expand their indications to the treatment of primary bone tumors. Finally, new expandable implants have been developed for the treatment of bone tumors in growing children. These devices may help solve some of the problems encountered with reconstruction of the growing skeleton.

SUMMARY

Recent discoveries in the molecular mechanisms of bone sarcomas may help to elucidate the pathogenesis of these rare diseases. This, combined with the recent findings of the anticancer effects of bisphosphonates, cyclooxygenase-2 inhibitors, and statins, may lead to the development of novel treatments for sarcomas of bone and of carcinomas metastatic to bone.

TP53 mutations and outcome in osteosarcoma: a prospective, multicenter study

PURPOSE

Mutations of the TP53 gene have been associated with resistance to chemotherapy as well as poor prognosis in many different malignancies. This is the first prospective study of the prognostic value of somatic TP53 mutations in patients with newly diagnosed extremity osteosarcoma.

PATIENTS AND METHODS

One hundred ninety-six patients with high-grade, nonmetastatic osteosarcoma of the extremities were enrolled from seven tertiary care institutions and observed prospectively for tumor recurrence (median follow-up duration, 44 months). All patients received neoadjuvant or adjuvant chemotherapy and surgery. Tumors were analyzed for the presence of TP53 mutations by polymerase chain reaction single-strand conformation polymorphism analysis and direct DNA sequencing. The association of the status of the TP53 gene with the risk of systemic recurrence was examined using survival analyses with traditional and histologic markers as prognostic factors.

RESULTS

Patient age was the only factor that varied with TP53 gene status (P = .05). No relationship was identified between TP53 status and systemic relapse (relative risk, 1.24; P = .41). Analyses based on missense or nonsense mutations gave similar results (P > .10). In multivariate analysis, large (> 9 cm) tumor size (relative risk, 1.9; P = .006) and poor histologic response (< or = 90% necrosis) to chemotherapy (relative risk, 2.14; P = .02) were the only significant independent predictors of systemic outcome.

CONCLUSION

We found no evidence that TP53 mutations predict for development of metastases in patients with high-grade osteosarcoma. Identification of other genes that influence chemotherapy response and clinical outcome in osteosarcoma is needed to facilitate further improvements in patient outcomes.

Elevated Physiologic Tumor Pressure Promotes Proliferation and Chemosensitivity in Human Osteosarcoma

PURPOSE

This study investigates the effect of constitutively raised interstitial fluid pressure on osteosarcoma physiology and chemosensitivity.

EXPERIMENTAL DESIGN

We did pressure and blood flow assessments at the time of open biopsy in patients with the diagnosis of high-grade osteosarcoma and correlated this to survival and chemotherapy-associated tumor necrosis. Osteosarcoma cell lines were then evaluated for proliferative and therapeutic indices in a replicated high-pressure environment.

RESULTS

Sixteen osteosarcomas in vivo were assessed and exhibited elevated interstitial fluid pressures (mean 35.2 +/- SD, 18.6 mmHg). This was not associated with significantly impeded blood flow as measured by a Doppler probe at a single site (P < 0.12). Nonetheless, greater chemotherapy-associated necrosis and associated longer survival were seen in tumors with higher interstitial fluid pressures (P < 0.05). In vitro, cells undergo significant physiologic changes under pressure. Osteosarcoma cell lines grown in a novel hydrostatically pressurized system had variable cell line-specific growth proportional to the level of pressure. They were more proliferative as indicated by cell cycle analysis with more cells in S phase after 48 hours of pressurization (P < 0.01). There was a significant elevation in the cell cycle-related transcription factors E2F-1 (P < 0.03) and E2F-4 (P < 0.002). These changes were associated with increased chemosensitivity. Cells tested under pressure showed an increased sensitivity to cisplatin (P < 0.00006) and doxorubicin (P < 0.03) reminiscent of the increased chemotherapy-associated necrosis seen in tumors with higher interstitial fluid pressure in the clinical study.

CONCLUSIONS

The results of this study suggest that cells in the in vivo pressurized environment are at a higher state of regenerative activity than is demonstrable in conventional cell culture systems. Variations in tumor interstitial fluid pressure have the potential to alter chemotherapeutic effects.

Elucidation of the molecular mechanisms of malignant bone tumors: refining diagnosis and identifying novel targets for treatment

Primary bone tumors are rare, accounting for less than 0.2% of all cancers diagnosed yearly in the United States. Study of the molecular mechanisms of these diseases has given insight into their pathobiology. It has also identified molecular alterations that, if present, may be used in conjunction with histologic evaluation to further refine diagnosis, allowing cases to be stratified into prognostic groups more or less likely to show response to current cytotoxic protocols. Recent findings have lead to the identification of molecular pathways that may serve as targets of novel therapies, especially in the case of Ewing sarcoma. Telomere maintenance mechanisms are also emerging as potential targets for anticancer therapy. As the molecular mechanisms underlying malignant bone tumors are better understood, new anticancer agents targeting specific pathways are likely to emerge. This may make it possible to tailor treatment for each individual patient, using a combination of cytotoxic and targeted therapies based on the histologic and molecular profile of the patient's tumor.

Ewing Sarcomas Withp53Mutation orp16/p14ARFHomozygous Deletion: A Highly Lethal Subset Associated With Poor Chemoresponse

Purpose

EWS-FLI1 fusion type, p53 mutation, and homozygous deletion of p16/p14ARF have each been shown to be prognostically significant in Ewing sarcoma (ES). We provide the first combined prognostic analysis of these three molecular parameters in ES.

Patients and Methods

We studied 60 patients with ES (stage: localized in 54, metastatic in six). All cases were confirmed to contain the EWS-FLI1 (29 type 1, 12 type 2, 14 other types) or EWS-ERG fusions (five cases). Homozygous deletion of p16/p14ARF, and p53 mutations were determined by fluorescent in situ hybridization and Affymetrix (Santa Clara, CA) p53 GeneChip microarray hybridization, respectively.

Results

Eight cases (13.3%) contained point mutations of p53, and eight cases (13.3%) showed p16/p14ARF deletion, including one case with both alterations. Among 32 cases with data on histologic chemoresponse, all 10 with alterations in p53 or p16/p14ARF showed a poor chemoresponse (P = .03). Variables predicting poorer overall survival included p53 mutation alone (P < .001), either p53 or p16/p14ARF alteration (P < .001), and stage (P < .01). In multivariate analysis, alterations of p53 and/or p16/p14ARF as a single variable, was the most adverse prognostic factor (P < .001), followed by stage (P = .04). In a multivariate analysis with alterations of p53 and p16/p14ARF as separate variables, both were significant (P < .001 and P = .03, respectively). Six cases with p16/p14ARF deletion were also studied for co-deletion of the contiguous methylthioadenosine phosphorylase gene, and this was detected in four cases.

Conclusion

Alterations in p53 or p16/p14ARF are found in a fourth of ES cases and define a subset with highly aggressive behavior and poor chemoresponse.

Ankle instability after vascularized fibular harvest for tumor reconstruction

BACKGROUND

The vascularized fibular graft is an important tool in the reconstruction of defects caused by resections of orthopedic tumors. Children often undergo this form of reconstruction, but there is little information about the complications after vascularized fibular graft harvest in this age group.

METHODS

We present a series of 32 patients who underwent this procedure to reconstruct an extremity in our institution. There were 12 children and 20 adults.

RESULTS

The residual distal fibula was significantly longer in adults as compared with children (P < .048). Among children, 3 of 11 undergoing the procedure developed ankle instability, in distinction to adults, none of whom developed this complication (P < .041). This reflects a disruption of normal ankle function that develops in skeletally immature patients with a short residual fibula but not in patients with a longer residual fibula (P < .008). When the sum of patient age in years and residual fibula length in centimeters was less than 16, 3 of 6 patients developed deformity, in contrast to no deformity developing in the remaining 23 when the sum was >16 (P < .004). Adults were more likely to develop pain than instability.

CONCLUSIONS

Our series suggests that children with an age-length sum <16 should be considered for prophylactic tibiofibular synostosis creation.

Biomechanical analysis of anterior poly-methyl-methacrylate reconstruction following total spondylectomy for metastatic disease

STUDY DESIGN

Three reconstruction options were evaluated biomechanically following total spondylectomy using human cadaveric spine specimens. OBJECTIVES.: To evaluate and compare the stability of combined anterior and posterior fixation incorporating poly-methyl-methacrylate with alternative accepted reconstruction techniques.

SUMMARY OF BACKGROUND DATA

Total spondylectomy represents the most radical option for decompression in metastatic spinal cord compression. Poly-methyl-methacrylate is considered a useful adjunct in spinal column stabilization and arthrodesis; however, there is little published biomechanical data to support its use in this setting.

METHODS

Ten fresh-frozen human cadaveric spines (T9-L3) were used. After intact analysis, a total spondylectomy was performed at T12. Three potential reconstruction techniques were tested for their ability to restore stiffness to the specimen: 1) multilevel posterior pedicle screw instrumentation from T10-L2; 2) anterior instrumentation (ATL Z plate II) and rib graft at T11-L1 with multilevel posterior pedicle screw instrumentation from T10-L2; and 3) anterior cement (Simplex P) and pins construct (T12) with multilevel posterior pedicle screw instrumentation from T10-L2. Each of the three potential reconstruction techniques was tested on each specimen in random order using nondestructive testing under load control.

RESULTS

Only combined stabilization techniques (e.g., anterior instrumentation and rib graft with multilevel posterior pedicle screw instrumentation and anterior cement-and-pins construct with multilevel posterior pedicle screw instrumentation) restored stiffness to a level equivalent to or higher than that of the intact spine in all loading modes (P < 0.05). Anterior cement-and-pins construct with multilevel posterior pedicle screw instrumentation provided more stability to the specimen than anterior instrumentation and rib graft with multilevel posterior pedicle screw instrumentation in compression and flexion testing (P < 0.05). Posterior instrumentation alone did not restore stiffness to the intact level in compression and flexion testing (P < 0.005).

CONCLUSIONS

Combined anterior and posterior reconstruction using a cement construct provides equal to or more stability than the intact spine in all testing modes. Posterior stabilization alone is an inferior method of reconstruction following total spondylectomy. Poly-methyl-methacrylate has the advantage over traditional anterior reconstruction techniques in that it can be inserted using a posterior approach.

Percutaneous CT-guided biopsy of osseous lesion of the spine in patients with known or suspected malignancy

BACKGROUND AND PURPOSE

CT-guided spinal biopsy (CTGSB) is considered a safe and accurate procedure. Our goal was to determine the accuracy of a CTGSB of osseous spinal lesions in patients with known or suspected underlying malignancy in reference to major variables such as the radiographic appearance of the biopsied lesion and its location within the spinal column.

METHODS

We retrospectively reviewed results of 410 consecutive percutaneous CTGSB procedures of osseous spinal lesions. Biopsy was determined to be adequate if diagnostic tissue was obtained (n = 401) or unsatisfactory (n = 9) if only blood without cellular elements was present on final pathologic-cytologic examination.

RESULTS

The level of spinal biopsy was cervical in nine patients (2%), thoracic in 123 (31%), lumbar in 164 (42%), and sacral in 96 (25%). The overall diagnostic accuracy of CTGSB was 89%, with a false-negative rate of 11%. Biopsy of lytic lesions yielded an accurate diagnosis in 93% (220 of 236). Despite technical challenges inherent to biopsy of sclerotic lesions, diagnostic accuracy was 76% (63 of 83), although more importantly, 24% (20 of 83) of the results in sclerotic lesions were falsely negative.

CONCLUSION

CTGSB of osseous spinal lesions is an important tool in the workup of patients with known or suspected underlying neoplastic disease. However, a negative result must be confirmed with either close follow-up or, preferably, open biopsy, especially in cases of sclerotic lesions for which diagnostic accuracy is decreased and the false-negative rate is high.

Divergent patterns of telomere maintenance mechanisms among human sarcomas: sharply contrasting prevalence of the alternative lengthening of telomeres mechanism in Ewing's sarcomas and osteosarcomas

Two types of telomere maintenance mechanisms (TMMs) have been described in human tumors: telomerase activation and alternative lengthening of telomeres (ALT). Although the vast majority of epithelial tumors rely on telomerase activation, many mesenchymal tumors rely on ALT for telomere maintenance, but within this tumor group, the TMMs used by translocation-associated sarcomas have not been systematically studied. We studied telomere lengths and telomerase expression and activity in 30 uncultured tumor samples and in 10 cell lines of Ewing's sarcoma, a prototypical translocation-associated sarcoma, and compared the data to an identical analysis of 60 osteosarcomas, the most common type of sarcoma lacking a specific translocation. Telomerase activity was demonstrated in 21 Ewing's sarcoma tumor samples (70%) and in 9 of 10 Ewing's sarcoma cell lines. Evidence of ALT, indicated by the presence of long and heterogeneous telomeres, was observed only in the cell line without telomerase activity and in none of the 30 Ewing's sarcoma tumor samples. The 9 Ewing's sarcoma patients whose tumors lacked detectable telomerase activity did not differ significantly from the remaining patients in age, stage, EWSR1-FLI1 fusion type, prevalence of TP53 point mutations, or overall survival. The low prevalence of ALT in Ewing's sarcoma contrasted sharply with our data on TMMs in 60 osteosarcomas, which showed ALT in 38 of 60 cases (P<0.0001). The present study, together with emerging published data on other sarcoma types, suggests that a predominance of telomerase activation in the absence of ALT may characterize sarcomas with specific chromosomal translocations (such as Ewing's sarcoma), whereas a high prevalence of ALT appears typical of sarcomas with nonspecific complex karyotypes (such as osteosarcoma).

VEGF expression in osteosarcoma correlates with vascular permeability by dynamic MRI

Dynamic enhanced magnetic resonance imaging has been used to assess tumor angiogenesis in osteosarcoma. Vascular endothelial growth factor has been shown to correlate with pulmonary metastasis and a poor prognosis in osteosarcoma. The purpose of this investigation was to determine whether vascular endothelial growth factor expression in osteosarcoma correlates with vascular permeability detected by dynamic enhanced magnetic resonance imaging and to explore the role of dynamic enhanced magnetic resonance imaging as a noninvasive means of assessing tumor angiogenic activity. Fifty-five osteosarcoma patients with osteosarcoma enrolled in a treatment protocol that included dynamic enhanced magnetic resonance imaging. In 15 patients, tumor tissues were available for vascular endothelial growth factor immunohistochemical studies. A two-compartment model used the exchange rate constants (kep) between the plasma and tumor compartments to quantify vascular permeability during dynamic magnetic resonance imaging studies. Immunohistochemical staining for vascular endothelial growth factor was graded according to the intensity and number of positively stained cells. Vascular endothelial growth factor-positive tumors showed higher mean vascular permeability when compared with vascular endothelial growth factor-negative tumors. Vascular permeability also correlated with increasing vascular endothelial growth factor expression. The preliminary results in this study show an association between vascular endothelial growth factor and dynamic MR signal enhancement in osteosarcoma. Dynamic enhanced magnetic resonance imaging should be investigated as a means to prognosticate osteosarcoma patients with osteosarcoma according to their tumor angiogenic activity.

Dickkopf 3 inhibits invasion and motility of Saos-2 osteosarcoma cells by modulating the Wnt-beta-catenin pathway

Osteosarcoma (OS) is a primary malignancy of bone with a tendency to metastasize early. Despite intensive chemotherapy and surgical resection, approximately 30% of patients still develop distant metastasis. Our previous work using clinical OS samples suggested that expression of the Wnt receptor LRP5 might be associated with tumor metastasis. In the present study, we used a Dickkopf (Dkk) family member and a dominant-negative LRP5 receptor construct to modulate Wnt signaling in OS cells. Saos-2 cells, which ectopically express Dkk-3, do not undergo apoptosis and exhibit enhanced resistance to serum starvation and chemotherapy-induced cytotoxicity. Transfection of Dkk-3 and dominant-negative LRP5 into Saos-2 cells significantly reduces invasion capacity and cell motility. This blockade is associated with changes in cell morphology consistent with a less invasive phenotype. In addition, Dkk-3 and dominant-negative LRP5 also induce changes in beta-catenin localization consistent with an increase in cell-cell adhesion. Taken together, these results support a possible role for Wnt signaling in the pathobiology and progression of human OS.

Epiphyseal osteoblastoma of tibia with xanthomatous stromal reaction

Osteoblastoma occurring in long bones has a distinctive predilection for the metaphysis and the diaphysis. Epiphyseal location is rare. Although variation in histologic patterns is a well-known feature of this tumor, xanthomatous stromal reaction has not yet been described. We report a case of a 34-year-old man who developed an osteoblastoma primarily located in the epiphysis of his left tibia with extension into the metaphysis. The striking histologic features included a prominent xanthoma-like stroma consisting of foamy histiocytes in addition to focal areas with classical configuration of an osteoblastoma. The significance of this finding is discussed.

Expression of LDL receptor-related protein 5 (LRP5) as a novel marker for disease progression in high-grade osteosarcoma

The Wingless-type (Wnt) family of proteins and its coreceptor LRP5 have recently been implicated in human skeletal development. Wnt pathway modulates cell fate and cell proliferation during embryonic development and carcinogenesis through activation of receptor-mediated signaling. Osteosarcoma (OS) is a bone-forming tumor of mesenchymal origin whose growth control has been linked to autocrine or paracrine stimulation by several growth factor families. We examined 4 OS cell lines for WNT1, WNT4, WNT5A, WNT7A, WNT11, FZD1-10 and LRP5 expression by reverse transcription polymerase chain reaction (RT-PCR). In addition, RT-PCR for LRP5 expression was performed in 44 OS patient samples and the findings were correlated with clinical data. Expression profiling of Wnts and their receptors revealed the presence of several isoforms in OS cell lines. Overall, 22/44 (50%) of OS patient samples showed evidence of LRP5 expression. Presence of LRP5 correlated significantly with tumor metastasis (p = 0.005) and the chondroblastic subtype of OS (p = 0.045). In addition, patients whose tumors were positive for LRP5 showed a trend toward decreased event-free survival (p = 0.066). No significant association was found between LRP5 expression and age, gender, site of disease, site of metastasis or degree of chemotherapy-induced tumor necrosis. Sequencing of exon 3 of LRP5 in 10 OS patient-derived cell cultures showed no activating mutation of LRP5. These results showed that expression of LRP5 is a common event in OS and strongly suggest a role for LRP and Wnt signaling in the pathobiology and progression of this disease.

The patterns of relapse in osteosarcoma: the Memorial Sloan-Kettering experience

BACKGROUND

With the introduction of intensive high-dose chemotherapy for the treatment of osteosarcoma, changes in the pattern of metastases observed at relapse have been reported. To further investigate this hypothesis, the relapse patterns among groups receiving chemotherapy regimens of variable intensity at Memorial Sloan-Kettering Cancer Center were analyzed.

PROCEDURE

All patients treated with the protocols T4, T5, T7, T10, and T12 were included. Patients were divided into two groups, one including those patients treated with less intense therapy (T4, T5, and T7) and the other, those treated with current regimens (T10 and T12).

RESULTS

Of the 25 patients who relapsed on the earlier protocols, 76% relapsed to the lungs, 8% had local recurrences, and 16% distant metastases to the bone. The median time to first relapse was 12 months. Of the 69 patients who relapsed on the T10 and T12 protocols, 75% relapsed in the lungs, 9% had local recurrences, and 16% distant bone metastases. The median time to first relapse was 17 months. There was no statistically significant difference in the timing of relapse between the two groups studied, although a longer median time to relapse was observed for patients treated on the later protocols. The range of time to relapse was also wider in the later protocols.

CONCLUSIONS

These data do not support the hypothesis that patterns of relapse are changing with alterations in osteosarcoma treatment. This limited single institutional experience can be explored further in the context of a multi-institutional effort.

Salvage reconstruction for lateral ankle instability using a tendon allograft

Lateral ligamentous instability may result after an inversion injury to the ankle. Although it generally responds well to nonsurgical treatment, recurrent cases may warrant surgical intervention. There is extensive literature detailing various procedures designed to restore lateral ankle stability. We describe a case in which a patient had a distal fibulectomy for multiple symptomatic osteochondromas, with reconstruction of the lateral ligament complex using peroneus brevis tendon. The patient subsequently disrupted this surgical construct with a severe inversion injury and had recurrent lateral ankle instability. The lateral ligament complex then was reconstructed using a tibiotalar bone-tendon allograft directed to counteract inversion forces. Fourteen years after the procedure, the patient remains satisfied with a painless, stable ankle. The described technique provides a salvage reconstruction of the lateral ligament complex using allograft tissue, in the unique setting of an absent fibula and deficient peroneus brevis tendon.

PMMA to stabilize bone and deliver antineoplastic and antiresorptive agents

Antineoplastic and antiresorptive drugs added to polymethylmethacrylate cement may prevent local cancer progression and failure of reconstructive devices used to treat patients with pathologic fractures. We tested the mechanical properties of cement containing various amounts of the drugs and found that as much as 2 g of either doxorubicin or pamidronate can be added to Simplex cement and the cement retains 87% of its compressive and tensile strength after 6 months of wet storage. Approximately 1 mg pamidronate elutes from experimental pellets. One half of the drug elution occurs within the first day in experiments that combined doxorubicin and pamidronate, and within 3 days when pamidronate was the only additive. Cement containing these drugs seems to be strong enough, but its fatigue strength should be tested before using it clinically. Sufficient amounts of the tested drugs elute to have potential biologic activity.

Long-term event-free survival after intensive chemotherapy for Ewing's family of tumors in children and young adults

PURPOSE

To improve the long-term event-free survival of patients with Ewing's family of tumors (EFTs) using high-dose, short-term chemotherapy.

PATIENTS AND METHODS

P6 was a prospective study of previously untreated patients with newly diagnosed EFTs. Patients received seven cycles of chemotherapy. Cycles 1, 2, 3, and 6 consisted of cyclophosphamide 2,100 mg/m2/d on days 1 and 2, and a 72-hour continuous infusion of doxorubicin 75 mg/m2 and vincristine 2 mg/m2 starting day 1. Cycles 4, 5, and 7 consisted of 5 consecutive days of ifosfamide 1,800 mg/m2/d and etoposide 100 mg/m2/d.

RESULTS

Sixty-eight patients were enrolled from 1991 to 2001 (median age, 18.7 years; range, 3.7 to 39.9 years). At diagnosis, 44 patients had local-regional disease, and 24 had distant metastases. The 4-year event-free survival (EFS) rate for patients with local-regional disease is 82%; overall survival (OS) is 89%. The 4-year EFS rate for patients with distant metastases is 12%; the OS rate is 17.8%. All events occurred within 51 months of diagnosis. Four patients with distant metastases had progressive disease during therapy, and no patient with local-regional disease experienced disease progression during therapy.

CONCLUSION

Sustained EFS and OS can be achieved with intensive chemotherapy in children and young adults with local-regional EFTs. This therapy is relatively ineffective in the treatment of metastatic EFTs.

Phase II study of ecteinascidin 743 in heavily pretreated patients with recurrent osteosarcoma

BACKGROUND

Recurrent osteosarcoma is a drug-resistant disease with a dismal prognosis. The objective of this Phase II study was to evaluate the activity of ecteinascidin 743 (ET-743) as a salvage therapy in these patients.

METHODS

Patients with recurrent osteosarcoma who had received standard chemotherapeutic agents were eligible. ET-743 was administered at a dose of 1500 microg/m(2) as a 24-hour infusion every 3 weeks. Pharmacokinetic studies were performed during the first cycle.

RESULTS

Twenty-five patients were enrolled, 23 of whom were assessable for response (median age of 18 years; range, 12-67 years). The median number of previous chemotherapeutic agents was five (range, three to eight previous agents). Sixty-one cycles were administered (median number of cycles per patient was 2; range, 1-9 cycles per patient). Three patients (12%) achieved minor responses (49% 36% and 25%, respectively). Fifteen patients (60%) developed a transient elevation of hepatic transaminases (Grade 3 or 4 [according to the National Cancer Institute Common Toxicity Criteria]), which was not cumulative. Grade 3 or 4 neutropenia and thrombocytopenia were observed in 12 patients (48%) and 6 patients (24%), respectively. The mean area under the curve (AUC) in 4 patients experiencing Grade 4 toxicity (76.4 +/- 29.3 ng x hr/mL) was significantly greater (P = 0.034) than that in those for whom the most severe toxicity was Grade 3 (39.5 +/- 17.2 ng x hr/mL [n = 12]) or Grade 1-2 (52.6 +/- 15.6 ng x hr/mL [n = 5]). There were no other significant correlations found between pharmacokinetic variables and patient characteristics, toxicity, or therapeutic response.

CONCLUSIONS

ET-743 was found to be well tolerated in heavily pretreated osteosarcoma patients but had limited antitumor activity as a single agent. The combination of ET-743 with cisplatin or doxorubicin should be considered.

Osteogenic and Ewing sarcomas: estimation of necrotic fraction during induction chemotherapy with dynamic contrast-enhanced MR imaging

Dynamic contrast material-enhanced magnetic resonance (MR) images of primary osteogenic sarcoma (n = 19) and Ewing sarcoma (n = 10) were reviewed in 29 patients undergoing induction chemotherapy before surgery. Histogram distributions containing the initial slope and pharmacokinetic model parameters from individual voxels within each tumor were fitted for each patient. The histogram analysis of initial slope from the tumor correlated well with percentage necrosis as determined at pathologic examination (r = 0.60, P <.001), as did a two-compartment pharmacokinetic model (r = 0.64, P <.001). Both methods predicted tumors with clinically important degrees of necrosis (ie, > or =90%) in a large majority of cases. The ability to determine response to induction chemotherapy by means of noninvasive monitoring of necrotic fraction with perfusion MR imaging methods may provide useful prognostic information and help surgical planning.

mRNA expression levels of E2F transcription factors correlate with dihydrofolate reductase, reduced folate carrier, and thymidylate synthase mRNA expression in osteosarcoma

Previous studies have shown that decreased expression of the reduced folate carrier (RFC) and increased expression of dihydrofolate reductase (DHFR) are associated with intrinsic and acquired methotrexate resistance, respectively, in osteosarcoma (OS). It has also been shown in colorectal cancer that E2F-1 expression correlates with thymidylate synthase (TS) and, to a lesser extent, DHFR expression. To begin to investigate the regulation of DHFR and RFC expression in OS samples, mRNA expression of E2F-1 and E2F-4 were measured in OS tumor samples and related to DHFR, RFC, and TS mRNA expression. Using fluorescent quantitative real-time PCR, 112 human OS patient samples were investigated for potential E2F-1/E2F-4:DHFR, E2F-1/E2F-4:RFC, and E2F-1/E2F-4:TS correlations. The expression ranges for each gene are as follows: DHFR, 0.02-33.13 (median = 0.20); RFC, 0.02-229.13 (median = 1.91); TS, 0.01-9.99 (median = 0.15); E2F-1, 0.05-69.07 (median = 0.52); and E2F-4, 0.24-52.35 (median = 1.45). Spearman correlation coefficients (r(s)) for E2F-1:DHFR, E2F-1:RFC, E2F-1:TS, E2F-4:DHFR, E2F-4:RFC, and E2F-4:TS were calculated to be 0.53, 0.63, 0.60, 0.41, 0.58, and 0.33, respectively (P < 0.001). On the basis of this data, moderate correlations exist between E2F-1/E2F-4 and DHFR, RFC, and TS. These results suggest E2F-1/E2F-4 may play a role in the regulation of RFC expression, which has not been reported previously. The E2F transcription factors are also related to DHFR and TS expression in OS samples, suggesting a possible involvement in methotrexate resistance. Although E2F mRNA levels correlate with DHFR, RFC, and TS mRNA expression, additional experiments are necessary to determine the direct effects of these transcription factors and identify other proteins that may influence this relationship.

Absence of a telomere maintenance mechanism as a favorable prognostic factor in patients with osteosarcoma

There are two telomere maintenance mechanisms (TMMs) in human tumors, telomerase activation (TA) and, more rarely, the process termed alternative lengthening of telomeres (ALT). Unlike most carcinomas, sarcomas, including osteosarcomas (OS), have been reported to display TA and ALT in more balanced proportions and, thus, present an opportunity to examine the impact of different TMMs on clinical tumor behavior. We studied OS samples from 62 patients for molecular evidence of TA and ALT. Kaplan-Meier analysis demonstrated that the absence of both TA and ALT (in 18%) was more strongly associated with improved survival (P = 0.05) than were stage (P = 0.16) or chemotherapy response (P = 0.18) in this group of patients with OS. Subsets of OS cases with either TA or ALT did not differ significantly from each other in clinical outcome. There were no significant associations of presence, absence, or type of TMM with patient age, stage, or chemotherapy response. Thus, the absence of a detectable TMM may identify a favorable clinical subset of OS patients. Our study also suggests that the likelihood of detecting correlations between TMMs and clinical outcome in studies of certain other tumor types might be improved if, in addition to TA, ALT is included in future analyses. Finally, we note that OS cases with a TA-/ALT+ phenotype seem to be as clinically aggressive as TA+ cases in terms of stage and clinical outcome.

Sequence alterations in the reduced folate carrier are observed in osteosarcoma tumor samples

High-dose methotrexate is a standard component of therapy for high-grade osteosarcoma. Its effectiveness may be limited by intrinsic and acquired resistance. Decreased reduced folate carrier (RFC) expression has been shown in approximately half of osteosarcomas at diagnosis. Mutations and polymorphisms in the RFC gene have been reported in various cell lines. The purpose of this study was to investigate sequence alterations in the RFC gene in osteosarcoma tumor samples. The entire coding region of the RFC gene in samples from 162 osteosarcoma patients was screened by DNA single-stranded conformational polymorphism, followed by direct sequencing of any region with altered mobility. A previously identified polymorphism at cDNA position number 174 of RFC exon 2 was observed. Sixty-one samples (37.6%) were heterozygous with both A/G at this position (His(27)/Arg(27)), 52 samples (32.2%) were homozygous with G (Arg(27)), and 49 samples (30.2%) were homozygous with A (His(27)). Fifteen (9.2%) samples were identified with other RFC sequence variants in exon 2, none of which have been reported. The sequence variants in exon 2 included a G to A substitution at cDNA position 231, a G to A substitution at cDNA position 155, a C to T substitution at cDNA position 114, and a T to C substitution at cDNA position 104, resulting in a serine to asparagine substitution at amino acid 46, a glutamate to lysine substitution at amino acid 21, an alanine to valine substitution at amino acid 7, and a serine to proline substitution at amino acid 4, respectively. A deletion of A at cDNA position 126 resulting in a frameshift was also observed. Some of these variants were observed in multiple samples. Eight samples had altered single-stranded conformational polymorphism patterns in exon 3 that were associated with nucleotide changes that altered the amino acid sequence. All of these RFC sequence variants appeared to be heterozygous. Heterozygous C/T and homozygous C also were observed at RFC cDNA position 790 in exon 3, which does not alter the amino acid coding sequence. This study shows that RFC sequence alterations are frequent in samples from osteosarcoma patients. Additional studies are under way to determine the clinical significance of these sequence alterations and their effect on methotrexate transport and resistance.

Metachronous skeletal osteosarcoma in patients treated with adjuvant and neoadjuvant chemotherapy for nonmetastatic osteosarcoma

PURPOSE

The prognosis for patients who develop metachronous skeletal osteosarcoma (OS) has been considered grave compared with that for patients with relapse limited to the lungs. We investigated the incidence and outcome of metachronous skeletal OS after initial treatment of the primary tumor.

PATIENTS AND METHODS

Twenty-three (median age 18.7 years) of 426 patients with nonmetastatic, high-grade primary OS treated at Memorial Sloan-Kettering Cancer Center (New York, NY) between February 1973 and May 2000 developed metachronous skeletal OS. Initial therapy included combination chemotherapy and surgery. Treatment of subsequent relapses consisted of chemotherapy or radiation alone or surgery with or without additional individualized chemotherapy.

RESULTS

The median time from the diagnosis of primary OS to the development of metachronous OS was 1.4 years (range, 0.2 to 11.3 years). Median survival was 1.5 years (95% confidence interval [CI], 0.8 to 6.9 years). Two- and 5-year postmetachronous overall survival was 43.5% (95% CI, 23.2% to 63.7%) and 33% (95% CI, 13% to 53%), respectively. At last follow-up (range, 0.1 to 12.8 years), five (30.4%) patients were alive with no evidence of disease (range, 1.7 to 12.8 years; median, 4.4 years). For 11 patients who developed metachronous OS 24 months or more from initial diagnosis, 5-year postmetachronous survival rate for patients receiving combined modality versus monotherapy was 83% (95% CI, 54% to 100%) and 40% (95% CI, 0% to 83%), respectively.

CONCLUSION

In a small subset of patients who developed late metachronous OS, combined-modality therapy with surgery and aggressive chemotherapy may result in long-term postmetachronous survival. This implies that principles used in treatment of primary OS may be applied to patients with late metachronous skeletal OS.

Second malignant neoplasms in long-term survivors of osteosarcoma: Memorial Sloan-Kettering Cancer Center Experience

BACKGROUND

The authors investigated the incidence and relative risk of secondary malignant neoplasms in long-term survivors of osteosarcoma.

METHODS

A comprehensive list of 509 patients with primary osteosarcoma treated at our institution between February 1973 and March 2000 was identified. All study patients received chemotherapy and/or surgery on one of six different protocols (T4, 5, 7, 10, 12, and CCG-7921/POG-9351). Chemotherapy was scheduled for up to 40 weeks with some variations in the actual treatment period and consisted of various combinations of the following agents: high-dose methotrexate, doxorubicin, bleomycin, cyclophosphamide, dactinomycin, vincristine, cisplatin, and ifosfamide.

RESULTS

Secondary malignant neoplasms (SMN) occurred in 14 of 509 patients. Only one had pulmonary metastasis at diagnosis and subsequent multiple recurrences that required thoracotomies and further modification of the chemotherapy regimen. The median age at diagnosis for osteosarcoma was 16.6 years (range, 3.1-74.4 years). The median follow-up was 5.2 years (range, 0.1-25.0 years). The time interval from diagnosis of the primary osteosarcoma to the development of SMN was 1.3-13.1 years (median, 5.5; 95% confidence interval [CI], 3.6-9.6). The most common SMN occurred in the central nervous system (n = 4): anaplastic glioma, meningioma, high-grade glioma, and maxillary astrocytoma. There were two cases of acute myeloid leukemia and one case each of myelodysplastic syndrome, non-Hodgkin lymphoma, high-grade pleomorphic sarcoma, leiomyosarcoma, fibrosarcoma, breast carcinoma, and mucoepidermoid carcinoma. The overall 5 and 10-year cumulative incidences of SMNs were 1.4% +/- 1.1% and 3.1% +/- 1.8%. The standardized incidence ratio was 4.6 (95% CI, 2.53-7.78, P = 0.00001) for the cohort and 3.64 (95% CI, 1.82-6.52, P = 0.0007) when patients with a history of retinoblastoma or Rothmund-Thomson syndrome were excluded.

CONCLUSIONS

The overall incidence of secondary malignancies in long-term survivors of osteosarcoma was significantly higher than the expected incidence of cancer in the general population. However, the standardized incidence ratios were much lower than those reported for Hodgkin disease and retinoblastoma. Although additional follow-up is warranted, the successes of current treatment regimens consisting of intensive, high-dose chemotherapy in combination with topoisomerase II inhibitors outweigh the risks.

Outcome of primary soft tissue sarcoma of the knee and elbow

PURPOSE

Concern is frequently raised regarding the tolerance of irradiation over a joint space. The purpose of this study was to determine the outcome in terms of relapse and potential complications in patients with knee and elbow soft tissue sarcoma treated with limb-sparing surgery with or without adjuvant radiotherapy (RT).

METHODS AND MATERIALS

A review of our prospective database between June 1982 and December 1999 identified 86 adult patients with primary soft tissue sarcoma arising from the knee (n = 65; 76%) or elbow (n = 21; 24%) treated with limb-sparing surgery. Tumors had high-grade histologic features in 72% and were >5 cm in 48% of patients. Adjuvant RT was given to 46 (54%) of 86 patients. The type of RT was postoperative external beam RT in 63% and brachytherapy in 37%. Of the 46 patients who received RT, 85% (n = 39) had deep, 78% (n = 36) high-grade, and 54% (n = 25) >5-cm tumors. Complications were assessed in terms of wound complications requiring repeated surgery, bone fracture, nerve damage, and joint stiffness.

RESULTS

With a median follow-up of 48 months (range 4-175), the 5-year actuarial rate of local control, distant control, and overall survival was 75% (95% confidence interval [CI] 64-85%), 82% (95% CI 73-91%), and 81% (95% CI 71-91%), respectively. The 5-year local control rate for patients who received RT was 80% vs. 71% for those who did not (p = 0.3). The type of RT did not significantly influence the local control rate. Patients treated with external beam RT had a 5-year local control rate of 84% compared with 73% for those treated with brachytherapy (p = 0.4). On multivariate analysis, tumor size >5 cm retained its significance as an independent predictor of poor local control (p = 0.04; relative risk 3; 95% CI 1-6). In addition, high-grade histologic features emerged as an independent predictor of local recurrence (p = 0.02; relative risk 4; 95% CI 1-20). No statistically significant difference was found between the RT and no-RT group in terms of the 5-year actuarial rate of wound reoperation (10% vs. 3%, p = 0.1), bone fracture (3% vs. 5%, p = 0.5), or nerve damage (6% vs. 3%, p = 0.5). Joint stiffness was significantly higher in the RT group (24% vs. 0%, p = 0.001), but this stiffness was severe to moderate in only 2 patients.

CONCLUSION

On the basis of the findings of this retrospective review, adjuvant RT seems to be relatively well tolerated despite the inclusion of part of the joint space in the irradiation portal. Joint stiffness was seen more frequently with adjuvant RT, but it was moderate to severe in only a small number of patients.

Soft-tissue flap coverage maximizes limb salvage after allograft bone extremity reconstruction

Limb salvage after extremity tumor ablation may include the use of allograft bone. The primary complication of this method is infection of the allograft, which can lead to limb loss in up to 50 percent of cases. The purpose of this study is to evaluate the efficacy of primary muscle flap coverage in the setting of allograft bone limb salvage surgery. This study is a prospective review of all patients with flap coverage of extremity allografts over the 10-year period 1991 to 2001. There were 20 patients (11 male and nine female patients) with an average age of 28 years (range, 6 to 72 years). Flap coverage was primary in 16 patients and delayed in four. Delayed coverage was performed for failed wounds that did not have a primary soft-tissue flap. Pathologic findings included osteosarcoma in nine patients, Ewing sarcoma in five patients, malignant fibrohistiocytoma in two patients, chondrosarcoma in two patients, synovial sarcoma in one patient, and leiomyosarcoma in one patient. Allograft reconstruction was performed for the upper extremity in 12 patients and for the lower extremity in eight patients. Flap reconstruction was accomplished with 20 pedicle flaps in 17 patients (latissimus dorsi, 12; gastrocnemius, four; soleus, three; and fasciocutaneous flap, one) and four free flaps (rectus abdominis, three; latissimus dorsi, one) in four patients. All pedicled flaps survived. There was one flap failure in the entire series, which was a free rectus abdominis flap. This case resulted in the only limb loss noted. The follow-up period ranged from 1 to 50 months (average, 12.35 months). At the time of final follow-up, three patients were dead of disease and 17 were alive with intact extremities. The overall limb salvage rate in the setting of bone allograft and soft-tissue flap coverage was 95 percent (19 of 20). Reoperation for bone-related complications was required in 50 percent (two of four) of cases receiving delayed flap coverage compared with 19 percent (three of 16) of patients with primary flap coverage (statistically not significant). The results of this study support the use of soft-tissue flap coverage for allograft limb reconstruction. In this series, no limb was lost in the setting of a viable flap. Reoperation was markedly reduced in the setting of primary flap coverage. Pedicled or microvascular transfer of well-vascularized muscle can be used to wrap the allograft and minimize devastating wound complications potentially leading to loss of allograft and limb.

Methylthioadenosine phosphorylase gene deletions are common in osteosarcoma

PURPOSE

Methylthioadenosine phosphorylase (MTAP) is an enzyme essential in the salvage of cellular adenine and methionine synthesis. The MTAP gene is located in the 9p21 chromosomal region and its loss is frequently associated with deletion of the tumor suppressor genes p15(INK4b) and p16(INK4a). The aim of this study was to investigate the frequency of molecular alterations in MTAP in osteosarcoma.

EXPERIMENTAL DESIGN

Samples from patients with high-grade osteosarcoma (n = 96) and three osteosarcoma cell lines (HOS, SaOS-2, and U2OS) were analyzed. Genomic DNA was analyzed for MTAP gene deletions by PCR, RNA expression was measured by semiquantitative reverse transcription-PCR, and the protein levels were measured by immunohistochemistry.

RESULT

Deletion of at least one MTAP exon was found in 36 of 96 (37.5%) osteosarcoma patient samples and in one of the three cell lines (HOS). In all cases in which an MTAP gene deletion was observed, there was absence of detectable mRNA and protein. Furthermore, in four osteosarcoma patients, an MTAP deletion which was not evident at diagnosis was detected in subsequent tumor samples.

CONCLUSIONS

The MTAP gene is commonly deleted in osteosarcoma patient samples, leading to an absence of mRNA and protein expression; these results indicate that inhibitors of de novo purine synthesis or methionine depletion may be effective as treatments for osteosarcoma patients whose tumors fail to express MTAP.

Irinotecan for pediatric solid tumors: the Memorial Sloan-Kettering experience

PURPOSE

Irinotecan is a novel antineoplastic agent that works by inhibiting the enzyme, topoisomerase 1. Although not extensively studied in children, preclinical studies and several phase I trials indicate activity against a variety of relapsed solid tumors when administered on a protracted schedule. This report describes an institutional experience with irinotecan for the treatment of pediatric solid tumors.

PATIENTS AND METHODS

Twenty-two heavily pretreated children with multiply relapsed tumors were treated with courses of irinotecan at 20 mg/m2 per day for 10 days [(every day x 5) x 2].

RESULTS

Of the 19 patients evaluable for response, four achieved an objective response, including two complete responses and one partial response among four patients with rhabdomyosarcoma and one additional patient with an undifferentiated sarcoma with rhabdomyoblastic features, and one patient with a fibrosarcoma had stable disease. Among three patients with non-Hodgkin lymphoma, one achieved a partial response and one had stable disease. Diarrhea was the most commonly observed toxicity.

CONCLUSION

Irinotecan appears to have promising single-agent activity, particularly against rhabdomyosarcoma. with minimal hematopoietic toxicity, making it ideal for further evaluation in patients at high risk with newly diagnosed disease, particularly in combination with other active agents with nonoverlapping toxicities.

Resection replantation of the arm for sarcoma: an alternative to amputation

Resection-replantation for primary malignant tumors of the arm as an alternative to forequarter amputation first was reported in 1995. Segmental resection of the upper arm and replantation of the distal segment to the proximal humerus as an alternative to shoulder disarticulation for a large tumor of the humerus is reported. This procedure provides the patient with an aesthetically acceptable single-segment arm, which is useful for activities of daily living and recreation. There has been no local recurrence or metastasis at 5 years followup.

Resection of the sciatic, peroneal, or tibial nerves: assessment of functional status

BACKGROUND

Lower-extremity tumors are often treated by amputation rather than limb-sparing excision that sacrifices the sciatic nerve or a branch. This study assessed the functional outcome of major nerve sacrifice during limb-sparing resections for lower-extremity soft tissue sarcoma.

METHODS

Patients who underwent division of the sciatic, tibial, or peroneal nerve(s) during limb-sparing sarcoma surgery (January 1982 through June 2000) were identified. Eleven surviving patients evaluated their pre- and postoperative functional status by self-administered questionnaire (six sciatic, two tibial, and three peroneal nerve divisions).

RESULTS

Eighteen patients (10 male, 8 female; 14-84 years old) had nine primary and nine locally recurrent tumors. Tumors were high (16) or low grade (two). Five patients died of disease and two died of other causes. Median overall survival was 50 months. One of 11 reported increased pain. Eight had new phantom sensations with a median intensity of 4.5 (1 = least; 10 = most). All patients used an ankle brace to walk after a sciatic (four) or peroneal (one) division. Walking ability and distance after surgery was unchanged (nine), improved (one), and worsened (one). Standing improved in 7 of 11 patients. Proprioception in the affected extremity was retained in six. The median postoperative leg functional score was 8 (1 = worst; 10 = best). No patient developed foot ulcers. One patient underwent amputation for recurrence. All patients preferred their status over having an amputation.

CONCLUSIONS

Objectively and subjectively, division of the major lower-extremity nerves causes acceptable functional deficits in most patients. Resection of affected sciatic nerve (branches) during limb-sparing tumor surgery is an excellent alternative to amputation.

Adjuvant brachytherapy for primary high-grade soft tissue sarcoma of the extremity

BACKGROUND

We reviewed single-institution experience using brachytherapy alone for primary high-grade soft tissue sarcoma of the extremity.

METHODS

Between July 1982 and September 1997, 202 adult patients with primary high-grade soft tissue sarcoma of the extremity were treated with limb-sparing surgery and adjuvant brachytherapy. All patients underwent complete gross resection, but the margin of resection was microscopically positive in 18% of patients. The median dose of brachytherapy was 45 Gy delivered over 5 days. Tumors located in the shoulder or groin were defined as central location. Complications were assessed in terms of wound complications, bone fracture, and peripheral nerve damage.

RESULTS

With a median follow-up of 61 months, the 5-year local control, distant relapse-free survival, and overall survival rates were 84%, 63%, and 70%, respectively. On multivariate analysis, poor local control correlated with shoulder location, positive microscopic margins of resection, and nonshoulder upper extremity site. The 5-year actuarial rates of wound complications requiring reoperation, bone fracture, and grade > or = 3 nerve damage were 12%, 3%, and 5%, respectively.

CONCLUSIONS

Adjuvant brachytherapy provides adequate local control and acceptable morbidity that compares favorably with data reported for external beam radiation. Shoulder tumor location was identified as an independent prognostic factor for poor local control, mandating further improvement in the local management of these tumors.

Impact of SYT-SSX fusion type on the clinical behavior of synovial sarcoma: a multi-institutional retrospective study of 243 patients

Synovial sarcomas are aggressive spindle cell sarcomas containing in some cases areas of epithelial differentiation. They consistently show a specific t(X;18;p11;q11), which usually represents either of two gene fusions, SYT-SSX1 or SYT-SSX2, encoding putative transcriptional proteins differing at 13 amino acid positions. Previous studies have suggested that patients with SYT-SSX2 tumors do better than those with SYT-SSX1 tumors, but the study groups were too limited to be conclusive. To address this issue more definitively, we collected data on SYT-SSX fusion type, pathology, and clinical course in a retrospective multi-institutional study of 243 patients (age range, 6-82) with synovial sarcoma. SYT-SSX1 and SYT-SSX2 fusions were detected in 147 tumors (61%) and 91 tumors (37%), respectively. Histologically, 61 (25%) were classified as biphasic type and 180 (74%) as monophasic type based on the presence or absence of areas of glandular epithelial differentiation, respectively. Median and 5-year overall survivals for the SYT-SSX1 and SYT-SSX2 groups were 6.1 years and 53%, and 13.7 years and 73%, respectively. Overall survival was significantly better among SYT-SSX2 cases (P = 0.03), among cases localized at diagnosis (P < 0.0001), and among patients with primary tumors < 5 cm in greatest dimension (P = 0.01). Age, sex, histological type, and axial versus peripheral primary site had no impact on overall survival. The impact of fusion type on survival remained significant when stratified for primary tumor size (P = 0.03) but was no longer significant when stratified for disease status at presentation. This may reflect the tendency for patients with SYT-SSX1 tumors to present more often with metastatic disease (P = 0.05). Cox regression identified disease status (P < 0.0001) and primary tumor size (P = 0.04) as the only factors independently predictive of overall survival in the subset of 160 patients with information on all of the factors. Within the subset of patients with localized disease at diagnosis (n = 202), the median and 5-year survival for the SYT-SSX1 and the SYT-SSX2 groups were 9.2 years and 61% versus 13.7 years and 77%, respectively. Patients whose tumors contained the SYT-SSX2 fusion (P = 0.08) or were smaller (P = 0.12) showed a trend toward better survival by log-rank test, whereas tumor histology had no impact (P = 0.8). In a Cox regression analysis considering all of the factors, SYT-SSX fusion type emerged as the only independent significant factor (P = 0.04) for overall survival within the subset of 133 patients with localized disease at diagnosis who had information on all of the factors. Among other comparisons, there was a strong association of fusion type and morphology (P < 0.001), with almost all of the SYT-SSX2 tumors showing absence of glandular differentiation (monophasic histology) and almost all of the biphasic tumors containing SYT-SSX1. There was also a statistically significant association of fusion type and patient sex (P = 0.03); specifically, the male:female ratio of SYT-SSX1 cases was 1:1, whereas for SYT-SSX2 cases, it was close to 1:2. Overall, SYT-SSX fusion type appears to be the single most significant prognostic factor by multivariate analysis in patients with localized disease at diagnosis. SYT-SSX fusion type also appears to exert part of its impact on prognosis before presentation through its association with stage at diagnosis. In addition, the associations of SYT-SSX fusion type with patient sex and tumor epithelial differentiation point to interesting mechanistic biological differences.

Intralesional resection of primary and metastatic sarcoma involving the spine: outcome analysis of 59 patients

OBJECTIVE

Surgery plays an important role in achieving local tumor control and cure for primary and metastatic tumors of the spine. As has been established with regard to sarcomas at extraspinal sites, these goals may best be achieved by en bloc resection with negative histological margins. Unfortunately, sarcomas of the spine often present with tumor patterns that are amenable only to intralesional resection, if neurological preservation is a priority. This study is a retrospective analysis of the long-term outcomes of patients who had operations for sarcomas of the spine using modern surgical approaches, intralesional resections, and spinal instrumentation.

METHODS

Between 1985 and 1997, 59 patients had spinal operations for sarcoma involving the extrasacral spine. Data regarding tumor histology, grade, surgical indications, patterns of spinal tumor involvement, and neurological and functional outcomes were reviewed at presentation and at tumor recurrence.

RESULTS

Thirty-five patients underwent a single operation, and 24 patients required reoperation for locally recurrent tumors. At presentation, only nine patients (15%) had tumors that were amenable to marginal or wide resections. Functional outcomes after initial spinal surgery and after operations performed at first tumor recurrence showed that 95% of patients had maintained or regained ambulation. Intradural extension of tumor was seen in 5 of 12 patients who had three or more operations for locally recurrent disease. The median survival from first spine operation was 18 months, and the median event-free interval between the first and second spine operations was 13 months.

CONCLUSION

Surgery for sarcoma of the spine is useful for maintaining or improving neurological and functional outcomes, but local tumor recurrences are common. Because of the anatomy of the tumor at presentation and concern for neurological preservation, few patients are candidates for marginal or wide resections.

Lack of correlation of functional scintigraphy with (99m)technetium-methoxyisobutylisonitrile with histological necrosis following induction chemotherapy or measures of P-glycoprotein expression in high-grade osteosarcoma

In osteosarcoma, some studies have suggested P-glycoprotein expression is a prognostic factor. The clearance of (99m)technetium hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been used in some tumor systems as an in vivo measure of P-glycoprotein-mediated efflux. In this study we explored the correlation between (99m)Tc-MIBI clearance and histological necrosis following induction chemotherapy and P-glycoprotein expression in osteosarcoma. The primary tumors of 20 patients with high-grade osteosarcoma were imaged at diagnosis with (99m)Tc-MIBI, and the uptake ratios and biological half-lives were calculated. P-Glycoprotein expression in the tumor tissue was determined immunohistochemically and by measuring mRNA expression of the multidrug resistance-1 gene. The histological necrosis following induction chemotherapy was assessed by the Huvos grading system. The biological half-life of (99m)Tc-MIBI ranged from 1.4 to 52.5 h. Seven of the 20 tumor samples had a favorable extent of necrosis following induction chemotherapy. The (99m)Tc-MIBI half-life and uptake ratio showed no correlation with histological necrosis following induction chemotherapy. The (99m)Tc-MIBI half-life and uptake ratio did not correlate with either measure of P-glycoprotein expression. The results of this pilot study indicate that (99m)Tc-MIBI imaging is not an effective predictor of histological necrosis following induction chemotherapy in high-grade osteosarcoma. (99m)Tc-MIBI imaging did not correlate with measures of P-glycoprotein expression in the tumor tissue.

Amputation for recurrent soft tissue sarcoma of the extremity: indications and outcome

BACKGROUND

Limb salvage after primary site failure of extremity soft tissue sarcoma is a challenging problem. Amputation may be the most effective treatment option in selected patients with local recurrence. We compared the outcome of patients treated with amputation versus limb-sparing surgery (LSS) for locally recurrent extremity sarcoma.

METHODS

From 1982 to 2000, 1178 patients with localized primary extremity sarcoma underwent LSS. Of these, 204 (17%) developed local recurrence. Eighteen (9%) required major amputation and the remainder underwent LSS, of which 34 were selected for matched-pair analysis according to established prognostic variables. Rates of recurrence or death were estimated by the Kaplan-Meier method. Following adjustment for prognostic variables, a Mantel-Haenszel test was used to compare the outcome between the two treatment groups.

RESULTS

Patients in each group were well matched. All patients had high-grade tumors deep to the fascia. Median time to local recurrence was similar for both groups. Median follow-up was 95 months. Amputation was associated with a significant improvement in local control of disease (94% vs. 74%; P = .04). We observed no difference in disease-free (P = .48), disease-specific (P = .74), or overall survival (P = .93) between the two groups. Median postrecurrence survival was 20 months and 5-year OS was 36% for the entire study group.

CONCLUSIONS

Limb-sparing treatment achieves local control in the majority of recurrent extremity sarcomas for which amputation is infrequently indicated. Amputation improves local disease control but not survival under these circumstances.

Interstitial fluid pressure and blood flow in canine osteosarcoma and other tumors

This study aims to characterize interstitial fluid pressure and blood flow in naturally occurring appendicular bone tumors in dogs because high pressure may influence the response of tumors to chemotherapy and radiation therapy. Eighteen client-owned dogs with naturally occurring appendicular bone tumors were included in this study. At the time of surgical biopsy, interstitial fluid pressure and blood flow were measured using wick-in-needle probes and laser Doppler flowmetry, respectively, within the soft tissue and bony components of the lesions and in normal muscle. Interstitial fluid pressure within the bony and soft tissue components of the tumors was significantly higher than interstitial fluid pressure in normal muscle. Blood flow in the bony component of the tumors was significantly lower than blood flow in normal muscle. There was no significant difference between blood flow in the soft tissue component of the tumors compared with that in normal muscle. Appendicular bone tumors in dogs have significantly higher interstitial fluid pressure and lower blood flow than do adjacent, unaffected soft tissues. The higher interstitial fluid pressure and lower blood flow may reduce tissue oxygenation and impede drug delivery. The effects of increased interstitial fluid pressure and decreased blood flow should be considered in the formulation of treatment strategies for the clinical management of appendicular bone tumors.

Biomechanical evaluation of the origin of the long head of the biceps tendon

PURPOSE

Lesions of the superior glenoid labrum extending anterior and posterior (SLAP) have recently been recognized as important sources of shoulder pain and dysfunction. Among the 4 described types of SLAP lesions, the type II SLAP involves detachment of the superior labrum from the bony glenoid and destabilization of the origin of the long head of the biceps tendon (LHBT). The purpose of this cadaveric biomechanical study was to evaluate the relative contribution regarding linear stiffness and displacement under load of the 2 origins of the LHBT: the superior glenoid labrum and the supraglenoid tubercle (the biceps anchor).

TYPE OF STUDY

Cadaveric biomechanical study.

METHODS

Seven pairs of fresh-frozen cadaveric shoulders were dissected free of all soft tissue except for the glenoid labrum and LHBT. Tension from 0 to 55 N was applied to the LHBT while keeping the tendon perpendicular to the face of the glenoid. Each specimen was tested for linear stiffness and biceps tendon displacement in the intact state, after releasing 1 of the LHBT origins, and after releasing the remaining origin.

RESULTS

The average stiffness of the LHBT origin was 103 N/mm. Sectioning the anchor alone resulted in a 52% reduction in linear stiffness, whereas only detaching the superior glenoid labrum from the 10 o'clock to the 2 o'clock position resulted in a 15% reduction in linear stiffness. Maximum displacement of the biceps tendon origin in the intact state at the 55 N load averaged 0.99 mm. With a minimum load applied, displacement changed less than 1 mm unless both origins were released.

CONCLUSIONS

The results indicate that the biceps anchor is the primary restraint of the LHBT and that the superior labrum is a secondary restraint in regard to linear stiffness. However, disruption of both restraints is required to produce the laxity typically seen in a type II SLAP lesion.

The der(17)t(X;17)(p11;q25) of human alveolar soft part sarcoma fuses the TFE3 transcription factor gene to ASPL, a novel gene at 17q25

Alveolar soft part sarcoma (ASPS) is an unusual tumor with highly characteristic histopathology and ultrastructure, controversial histogenesis, and enigmatic clinical behavior. Recent cytogenetic studies have identified a recurrent der(17) due to a non-reciprocal t(X;17)(p11.2;q25) in this sarcoma. To define the interval containing the Xp11.2 break, we first performed FISH on ASPS cases using YAC probes for OATL1 (Xp11.23) and OATL2 (Xp11.21), and cosmid probes from the intervening genomic region. This localized the breakpoint to a 160 kb interval. The prime candidate within this previously fully sequenced region was TFE3, a transcription factor gene known to be fused to translocation partners on 1 and X in some papillary renal cell carcinomas. Southern blotting using a TFE3 genomic probe identified non-germline bands in several ASPS cases, consistent with rearrangement and possible fusion of TFE3 with a gene on 17q25. Amplification of the 5' portion of cDNAs containing the 3' portion of TFE3 in two different ASPS cases identified a novel sequence, designated ASPL, fused in-frame to TFE3 exon 4 (type 1 fusion) or exon 3 (type 2 fusion). Reverse transcriptase PCR using a forward primer from ASPL and a TFE3 exon 4 reverse primer detected an ASPL-TFE3 fusion transcript in all ASPS cases (12/12: 9 type 1, 3 type 2), establishing the utility of this assay in the diagnosis of ASPS. Using appropriate primers, the reciprocal fusion transcript, TFE3-ASPL, was detected in only one of 12 cases, consistent with the non-reciprocal nature of the translocation in most cases, and supporting ASPL-TFE3 as its oncogenically significant fusion product. ASPL maps to chromosome 17, is ubiquitously expressed, and matches numerous ESTs (Unigene cluster Hs.84128) but no named genes. The ASPL cDNA open reading frame encodes a predicted protein of 476 amino acids that contains within its carboxy-terminal portion of a UBX-like domain that shows significant similarity to predicted proteins of unknown function in several model organisms. The ASPL-TFE3 fusion replaces the N-terminal portion of TFE3 by the fused ASPL sequences, while retaining the TFE3 DNA-binding domain, implicating transcriptional deregulation in the pathogenesis of this tumor, consistent with the biology of several other translocation-associated sarcomas. Oncogene (2001) 20, 48 - 57.

Human epidermal growth factor receptor 2 as a prognostic indicator in osteogenic sarcoma

Prognostic biologic factors that can be assessed at the time of diagnosis for patients with osteogenic sarcoma have not been identified. The current study was designed to evaluate the prognostic significance of the human epidermal growth factor receptor 2 as it relates to histologic response to preoperative chemotherapy and event-free survival. A retrospective immunohistochemical study was performed on material from patients who were newly diagnosed with osteogenic sarcoma who were treated according to the T12 protocol from the authors' institution between 1986 to 1993. Staining for HER2/erbB-2 was accomplished using standard monoclonal antibodies and methods. At the time of initial biopsy, 42.6% of the samples showed HER2/erbB-2 overexpression. Higher levels of expression were observed in samples from patients with clinically detectable metastases at initial presentation and at relapse. Expression of HER2/erbB-2 correlated with inferior event-free survival in patients with nonmetastatic disease (47% versus 79% at 5 years). In addition, HER2/erbB-2 expression was associated with significantly less tumor necrosis after preoperative chemotherapy as determined by the Huvos grading system. These data suggest that HER2/erbB-2 should be evaluated prospectively as a prognostic indicator and clinical trials using antibodies that target this receptor should be considered for the treatment of patients with osteogenic sarcoma.

Prognostic impact of P53 status in Ewing sarcoma

BACKGROUND

Disease stage at the time of diagnosis and response to therapy are the main prognostic factors for patients with Ewing sarcoma or peripheral neuroectodermal tumor (ES/PNET). The primary genetic alteration in ES/PNET, the fusion of the EWS gene with FLI1 or ERG, is diagnostically highly specific for these tumors, and molecular variation in the structure of the EWS-FLI1 fusion gene also is of prognostic significance. In contrast, secondary genetic alterations, such as P53 alterations, are relatively uncommon in ES/PNET, and their prognostic impact has not been extensively studied.

METHODS

Prechemotherapy, paraffin embedded, nondecalcified, primary tumor material in a well-characterized series of 55 patients with ES/PNET with defined EWS-FLI1 fusion transcripts (32 patients with type 1 and 23 patients with other types) was studied retrospectively by immunohistochemical techniques for cell cycle regulators and proliferative markers, such as P53, P21(WAF1), and Ki-67, as well as by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique for apoptosis. Nuclear P53 expression in > 20% of tumor cells was scored as aberrant overexpression. Histologic response to neoadjuvant chemotherapy was assessed.

RESULTS

Aberrant P53 expression (in > 20% of tumor cells) was present in 6 patients (11%) but showed no statistically significant correlation with disease stage, tumor size, proliferation rate (Ki-67), apoptotic rate (TUNEL), or EWS-FLI1 fusion type. By univariate analysis, the P53 > 20% group showed a significantly poorer overall survival among patients with localized disease (n = 43 patients) (P = 0.001) and in the entire study group (P = 0.01). In multivariate Cox analyses of overall survival, P53 > 20% was the strongest negative factor among prognostic factors available at the time of diagnosis (P = 0.001; relative risk [RR] = 9) and when chemotherapy response was included in the analysis (P53 > 20%: P = 0.01; RR = 10).

CONCLUSIONS

P53 alteration appears to define a small clinical subset of patients with ES/PNET with a markedly poor outcome. The current observations warrant a systematic prospective study with comprehensive P53 mutation analysis. [See related article on pages 793-9, this issue.]

Single-stage posterolateral transpedicle approach for spondylectomy, epidural decompression, and circumferential fusion of spinal metastases

STUDY DESIGN

Retrospective review of prospectively maintained institutional spine database.

OBJECTIVES

To assess the pain, neurologic, and functional outcome of patients with metastatic spinal cord compression using a posterolateral transpedicular approach with circumferential fusion.

SUMMARY OF BACKGROUND DATA

Patients with spinal metastases often have patterns of disease requiring both an anterior and posterior surgical decompression and spinal fusion. For patients whose concurrent illness or previous surgery makes an anterior approach difficult, a posterior transpedicular approach was used to resect the involved vertebral bodies, posterior elements, and epidural tumor. This approach provides exposure sufficient to decompress and instrument the anterior and posterior columns.

METHODS

During the past 15 months, 25 patients were operated on using a posterolateral transpedicular approach. The primary indications for surgery were back pain (15 patients) and neurologic progression (10 patients). All patients had vertebral body disease, and 21 patients had high-grade spinal cord compression from epidural disease as assessed by magnetic resonance imaging. Seven patients underwent preoperative embolization for vascular tumors. In each patient, the anterior column was reconstructed with polymethyl methacrylate and Steinmann pins and the posterior column with long segmental fixation.

RESULTS

All patients achieved immediate stability. Pain relief was significant in all 23 patients who had had moderate or severe pain. Neurologic symptoms were stable or improved in 23 patients. One patient with an acutely evolving myelopathy was immediately worse after surgery, and one patient had a delayed neurologic worsening, progressing to paraplegia.

CONCLUSIONS

The posterolateral transpedicular approach provides a wide surgical exposure to decompress and instrument the anterior and posterior spine. This technique avoids the morbidity associated with anterior approaches and provides immediate stability. Vascular tumors may be removed safely after embolization. Patients can be mobilized early after surgery.

Cartilage tumors: evaluation and treatment

The proper treatment of cartilaginous tumors is dependent on the clinicopathologic and radiologic findings. Enchondroma is a benign tumor that is usually asymptomatic and thus should be treated nonoperatively. Symptomatic enchondromas are often treated by intralesional excision. Intramedullary low-grade chondrosarcoma is a malignant tumor that is usually painful. The treatment of low-grade chondrosarcoma may range from intralesional excision with or without adjuvant therapy to wide excision. Although intralesional excisions have a higher bone and joint preservation rate than wide excisions, they may be associated with a higher local recurrence rate. Intermediate- and high-grade chondrosarcomas are treated with wide excisions. The treatment of these cartilaginous lesions should involve a multidisciplinary team including a musculoskeletal surgeon, a radiologist, and a pathologist.

Prognostic impact of INK4A deletion in Ewing sarcoma

BACKGROUND

The primary genetic alteration in > 95% of Ewing sarcomas (ES) is a specific fusion of EWS with FLI1 or ERG. Secondary genetic alterations possibly involved in progression of ES are not well understood. A recent study found loss of the negative cell cycle regulator gene INK4A in 8 of 27 ES samples (30%). To confirm these findings and evaluate their prognostic significance, the authors studied INK4A deletion in 41 ES samples from 39 patients.

METHODS

Using Southern blot analysis with an INK4A p16 cDNA probe, the intensity of the INK4A bands in ES DNA samples was normalized to that of a control probe and compared with nondeleted control DNA; > 50% signal reduction was scored as evidence of deletion. All ES tumor DNA samples previously were confirmed to have EWS rearrangements on the same Southern blots, using a cDNA probe spanning the EWS breakpoint region.

RESULTS

Tumors from 7 patients (18%) showed INK4A deletion independent of disease stage (localized or metastatic) or sample source (primary tumor or metastasis). INK4A was a strong negative factor for disease specific survival in univariate analysis (P = 0.001) and in multivariate analysis including stage (relative risk = 6; P = 0.001).

CONCLUSIONS

INK4A deletions appear to be the most frequent secondary molecular genetic alteration found to date in ES. Their possible clinical usefulness in identifying a subset of ES patients with poor prognosis merits systematic prospective analysis. [See related article on pages 783-92.]

Specificity of TLS-CHOP rearrangement for classic myxoid/round cell liposarcoma: absence in predominantly myxoid well-differentiated liposarcomas

Myxoid liposarcoma (LS), the most common subtype of LS, is known to be characterized by the specific t(12;16) resulting in a TLS-CHOP fusion in almost all cases. We wished to address the following questions: (i) Is this genetic hallmark also present in other types of LS with predominant myxoid change? (ii) What is the proportion of cases with the variant EWS-CHOP fusion? (iii) What is the optimal approach for Southern blot detection of TLS breakpoints? We identified 59 LS characterized histologically by >90% myxoid component, in which frozen tissue tumor was available for DNA extraction. These 59 LS with myxoid features were divided into 2 groups: 42 LS with classic myxoid/round cell appearance (myxoid LS) and 17 well-differentiated LS (WDLS) with a predominant (>90%) myxoid component. Within the myxoid LS group, 29 tumors were low grade and 13 high grade (>20% round cell component). Among the 17 predominantly myxoid WDLS, there were 15 low grade and 2 focally high grade tumors. In addition, we selected as control group, 20 LS of other histological types with minimal or no myxoid change (17 WDLS and 3 pleomorphic LS) and 13 myxofibrosarcomas. Southern blot analysis was performed in all cases using a CHOP cDNA probe, and in all CHOP rearranged cases using a TLS cDNA probe. Probe/enzyme combinations for Southern blot analysis were CHOP exon 3-4 cDNA probe with BamHI or SacI, TLS exon 3-6 cDNA probe with BclI. All 42 cases of myxoid LS showed a CHOP rearrangement and 38 of them also had a TLS rearrangement. Among the 4 myxoid LS without Southern blot evidence of TLS rearrangement, 1 showed an EWS-CHOP fusion by Southern blotting and reverse transcriptase-polymerase chain reaction and in another case, reverse transcriptase-polymerase chain reaction detected a TLS-CHOP fusion transcript. None of the predominantly myxoid WDLS and none of the tumors included in the control group showed rearranegements with CHOP probe. In addition, 12 predominantly myxoid WDLS, 10 other LS, and 5 myxofibrosarcoma from the control group were also tested for TLS rearrangement; all were negative. The TLS-CHOP fusion is highly sensitive and specific for the entity of classic myxoid/round cell LS. Other types of LS, even with a predominant myxoid component, lack the TLS-CHOP rearrangement, confirming that they represent a genetically distinct group of LS. The prevalence of the EWS-CHOP variant fusion was approximately 2% in this series. The optimal enzyme for TLS genomic breakpoint detection is BclI.

Gait characteristics of patients after proximal femoral replacement for malignant bone tumour

We analysed the gait characteristics of 15 patients with prosthetic reconstruction of the proximal femur after resection of a malignant bone tumour using stride analysis and measurement of oxygen consumption. Compared with normal volunteers their gait was slower, with less cadence and reduced stride length. The mean net energy cost of free walking was 141% of normal. The degree of asymmetry of the single-limb support time correlated with the free-walking velocity and the net energy cost. If they used a single cane the subjects walked with less cadence, longer stride length, and prolonged single-limb support times. The net energy cost of walking and asymmetry of the single-limb support time had a negative correlation with the strength of the hip abductor muscles. Their walking performance was better than that of six subjects who had hip disarticulation.

Monoclonality of multifocal myxoid liposarcoma: confirmation by analysis of TLS-CHOP or EWS-CHOP rearrangements

Multifocal presentation, defined as the presence of tumor at two or more anatomically separate sites, before the manifestation of disease in sites where sarcomas usually metastasize (e.g., lungs) occurs in about 1% of extremity soft tissue sarcomas (STSs). Debate still persists whether multifocal STSs represent an unusual pattern of metastasis or multiple separate primary tumors. Among STSs with multifocal presentation, myxoid liposarcoma is the predominant histological type. This subtype of liposarcoma contains the specific t(12;16) chromosomal translocation, which results in rearrangement of the TLS and CHOP genes that is clone specific at the DNA level. We, therefore, sought to address the question of clonality by molecular analysis in six patients who presented with either synchronous or metachronous multifocal myxoid liposarcoma. In all six cases, adequate frozen tumor was available for DNA extraction from at least two distinct anatomical sites. Southern blot analysis using CHOP, TLS, and EWS cDNA probes was performed on genomic DNA. Five cases contained a TLS-CHOP rearrangement, and one case had the variant EWS-CHOP fusion (seen in <5% of cases). The size of the rearranged CHOP fragment differed among the six patients, as expected, but was identical in all anatomically separate tumor samples from each patient. Likewise, the sizes of the rearranged bands observed with either the TLS or EWS probes supported the monoclonality of all cases. Our results confirm the monoclonal origin of multifocal myxoid liposarcoma, establishing the metastatic nature of distant soft tissue lesions in these cases. It remains unclear whether this unusual pattern of metastasis represents an intrinsic property of this subset of myxoid liposarcoma or merely a rare chance occurrence. The clinical outcomes observed in this small series suggest that the prognosis of multifocal myxoid liposarcoma is poor, regardless of its often bland or "low-grade" histological appearance.

MDR1 gene expression and outcome in osteosarcoma: a prospective, multicenter study

PURPOSE

Increased expression of the multidrug resistance gene (MDR1) has been implicated in osteosarcoma prognosis. This study represents the first prospective assessment of the prognostic value of MDR1 mRNA expression in patients with newly diagnosed extremity osteosarcoma.

PATIENTS AND METHODS

A series of patients with high-grade, nonmetastatic extremity osteosarcoma were enrolled from six tertiary care institutions and observed prospectively for tumor recurrence (median follow-up duration, 30 months). All patients were treated with (neo)adjuvant chemotherapy and surgery. Tumors from 123 patients were analyzed for MDR1 mRNA expression. The association of the level of MDR1 expression with the risk of systemic recurrence was examined using survival analyses with traditional and histologic markers as prognostic factors.

RESULTS

Using the highest MDR1 value for each patient, a dose-response relationship was not identified between the level of MDR1 expression and systemic relapse (relative risk, 1.15; P =.44). Analyses based on biopsy or resection values alone gave similar results (P =.11 and.41, respectively, log rank test). In multivariate analysis, large tumor size (> 9 cm) was the only significant independent predictor of systemic outcome (relative risk, 2.8; P =.002).

CONCLUSION

We did not identify any correlation between MDR1 mRNA expression and disease progression in patients with osteosarcoma. It is likely that alterations in other genes are involved in resistance to chemotherapy in osteosarcoma and that they play a more critical role than MDR1 in this disease.