Improvement in histologic response but not survival in osteosarcoma patients treated with intensified chemotherapy: a randomized phase III trial of the European Osteosarcoma Intergroup

The multidisciplinary management of osteosarcoma

Patients with suspected or confirmed osteosarcoma should be evaluated and treated at a comprehensive cancer center within a multidisciplinary sarcoma program that includes pediatric, medical and radiation oncologists, orthopedic and surgical oncologists, musculoskeletal pathologists, and radiologists. Successful treatment involves proper diagnosis, neoadjuvant and adjuvant multi-agent chemotherapy, and aggressive surgery with an emphasis toward limb-preserving procedures. Treatment of osteosarcoma should be undertaken within the framework of large cooperative group clinical trials for children, adolescents, and adults. Patients treated with osteosarcoma should be followed closely both for recurrence of disease and for development of late effects of the treatment of their cancer. The treatment of metastatic, recurrent and/or refractory disease is more controversial. Despite advances in systemic treatment, surgical technique, and supportive care, the overall outcome is still poor.

Risk stratification based on the clinical factors at diagnosis is closely related to the survival of localized osteosarcoma

BACKGROUND

Survival of osteosarcoma patients has reached a plateau with the addition of chemotherapy and in part predicted based on histologic response. Risk-adapted therapy might be an alternative approach. We aimed to identify risk groups using clinical variables available at time of diagnosis in order to better predict outcomes and form the basis for risk-adapted therapy.

METHODS

This retrospective study analyzed 288 patients with high-grade osteosarcoma of their extremities. Clinicopathologic variables were analyzed to identify factors relevant to risk stratification.

RESULTS

A risk assessment system was developed using age, maximal tumor length (MTL) and tumor location. Index scores were based on the sum total of factor scores, for each of the following: Age (years); "1" for >or=40 or 12-14 (female) or 13-15 (male), "0" for other ages; MTL (cm); "2" for >or=8, "1" for 6-8, "0" for <or=6; Tumor location; "1" for humerus, "0" for elsewhere. Index score 0 or 1 was assigned as low-risk, 2 as intermediate-risk, and 3 or 4 as high-risk. Of the 288 patients, 98 (34.0%) were designated as low-risk, 128 (44.4%) as intermediate-risk and 62 (21.6%) as high-risk. Risk group was related to histologic response and survival. While 63.3% of low-risk patients were good responders, only 43.0% and 33.9% of intermediate- and high-risk patients were good responders. Ten-year event-free survival (EFS) was 81.6 +/- 3.9% for low-risk group, but 31.6 +/- 6.0% for high-risk group.

CONCLUSION

We defined three risk groups that could be used as basis of risk-adapted therapy for osteosarcoma.

Effect of time to resumption of chemotherapy after definitive surgery on prognosis for non-metastatic osteosarcoma

BACKGROUND

The dose intensity of chemotherapy has been described as affecting the outcome of the treatment of a number of different types of tumors. A delay in the resumption of chemotherapy after definitive surgery for the treatment of osteosarcoma can decrease the overall dose intensity. The goal of this study was to assess the prognostic significance of the time to resumption of chemotherapy after definitive surgery in patients with localized osteosarcoma in an extremity.

METHODS

The relationships of the time between definitive surgery and resumption of chemotherapy with death and adverse events in 703 patients with a localized resectable osteosarcoma in an extremity (556 treated in the Children's Oncology Group [COG] Study [INT 0133] and 147 treated at five tertiary care cancer centers) were assessed with use of Cox proportional hazards models.

RESULTS

The twenty-fifth, fiftieth, and seventy-fifth percentiles of time from definitive surgery to resumption of chemotherapy were twelve, sixteen, and twenty-one days, respectively. Overall survival was poorer for patients who had had a delay of greater than twenty-one days before the resumption of chemotherapy compared with those who had had a shorter delay (hazard ratio = 1.57 [95% confidence interval = 1.04 to 2.36]; p = 0.03). Of seventy-one COG-study patients with postoperative complications, 32% (twenty-three) had a delay of more than twenty-one days before resumption of chemotherapy, but 20% (eighty-nine) of 444 patients with no complications had a similar delay.

CONCLUSIONS

In this retrospective analysis, increased time from the definitive surgery to the resumption of chemotherapy was found to be associated with an increased risk of death of patients with localized osteosarcoma in an extremity. Within the limitations of a retrospective study, the data indicate that it is best to resume chemotherapy within twenty-one days after definitive surgery. Surgeons, oncologists, patients, and those responsible for scheduling need to work together to ensure timely resumption of chemotherapy after surgery.

Immunohistochemical Estimates of Angiogenesis, Proliferative Activity, p53 Expression, and Multiple Drug Resistance Have No Prognostic Impact in Osteosarcoma: A Comparative Clinicopathological Investigation

Purpose. To investigate angiogenesis, multiple drug resistance (MDR) and proliferative activity as prognostic variables in patients suffering from osteosarcoma. Methods. Histologic biopsies from 117 patients treated in the period from 1972 through 1999 were immunohistologically investigated regarding angiogenesis (CD34), proliferative activity (MIB-1), and the expression of p53 and MDR (P-glycoprotein (Pgp); clones JSB-1, C494, and MRK16). Quantitative and semiquantitative scores of immunoreactive cells were analyzed statistically along with retrospectively obtained clinicopathologic variables. Results. Chemotherapy reduced the rate of amputations (P = .00002). The Pgp was overexpressed (score ≥2) in 48% of the primary, diagnostic biopsies, and high Pgp correlated with high Pgp in postsurgical specimens (P = .003). In contrast, no such associations were disclosed for estimates of angiogenesis (P = .64) and p53 (P > .32), whereas the MIB-1 index was reduced in the post-chemotherapy specimens (P = .02). The overall, disease-specific survival was 47%, increasing to 54% in patients receiving pre-operative chemotherapy. Statistical analyses showed prognostic impact exclusively by patient age and type of osteosarcoma. Discussion. The studied series of patients documented already prior to the chemotherapy era, a rather excellent survival and estimates of angiogenesis, proliferation, p53, and Pgp expressions, did not demonstrate sufficient power to serve as predictors of treatment response or survival.

Evaluation of chemotherapy response in osteosarcoma with FDG-PET

OBJECTIVE

The objective of this study is to evaluate the utility of positron emission tomography (PET) with 2-deoxy-[(18)F] fluoro-D-glucose (FDG) in the assessment of the chemotherapy response of osteosarcoma when compared with the degree of necrosis determined histologically.

METHODS

Whole-body FDG-PET scan was performed on 11 patients with osteosarcoma. All patients received neoadjuvant chemotherapy. The tumor size changes on magnetic resonance imaging; FDG-PET standardized uptake values prior to (SUV(1)) and following (SUV(2)) chemotherapy were analyzed and correlated with response to chemotherapy as assessed using histopathology in surgically excised tumors. Nine patients underwent FDG-PET scan both prior to and following neoadjuvant chemotherapy. The remaining two patients were examined only prior to surgery.

RESULTS

Histologically, five patients had a good histologic response to chemotherapy (>==90% necrosis). The changes in tumor size did not correlate with histologic response (P > 0.05). SUV(2) with good response was significantly lower than that with poor response (1.93 +/- 0.50, 5.86 +/- 2.55, respectively). Both the positive and negative predictive values of the SUV(2) of less than 2.5 for a good response were 100%. Patients with good response showed a significantly higher ratio of SUV2 to SUV1 (SUV(2:1)) than patients with poor response (0.74 +/- 0.11, 0.26 +/- 0.39, respectively, P < 0.05). The positive and negative predictive values of SUV(2:1) </= 0.5 for good and poor responses were 80% and 100%, respectively.

CONCLUSIONS

FDG-PET imaging of osteosarcoma correlates positively with histologic response to neoadjuvant chemotherapy. SUV(2) and SUV(2:1) could be feasible as non-invasive surrogate predictors of response in osteosarcoma patients.

Methotrexate for high-grade osteosarcoma in children and young adults

BACKGROUND

The majority of the currently used treatment protocols for osteosarcoma are based on a combination of doxorubicin, cisplatin, methotrexate (MTX) and/or ifosfamide, of which MTX seems to be one of the most active drugs. However, in the literature, this has not been unambiguously proven.

OBJECTIVES

To compare the effectiveness of treatment including MTX with treatment without MTX for children and young adults (up to 21 years) with primary high-grade osteosarcoma.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, issue 3, 2008), MEDLINE (1966 to July 2008) and EMBASE (1980 to July 2008). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing trials databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the effectiveness of treatment including MTX with treatment without MTX in the treatment of paediatric high-grade osteosarcoma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed the study selection. One reviewer performed the data extraction and quality assessment, which was checked by another reviewer.

MAIN RESULTS

We could not identify any studies in which the only difference between the treatment groups was the use of MTX.We did identify a RCT comparing MTX with cisplatin (n=30 children). The risk of bias in this study was difficult to assess due to a lack of reporting. Survival could not be evaluated, but no evidence of a significant difference in response rate between the treatment groups was identified (RR=0.44; 95% CI 0.17 to 1.13; P=0.09). A significant difference in the occurrence of toxicities in favour of MTX was identified, but with regard to quality of life treatment with cisplatin seemed to give better results.For other combinations of treatment including and not including MTX no studies were identified.

AUTHORS' CONCLUSIONS

Since no RCTs or CCTs in which only the use of MTX differed between the treatment groups were identified, no definitive conclusions can be made about the effects on antitumour efficacy, toxicities and quality of life of the addition of MTX to treatment of children and young adults with primary high-grade osteosarcoma. The same is true for combinations of treatment including and not including MTX other than treatment with MTX versus treatment with cisplatin. Only 1 RCT comparing MTX with cisplatin treatment was available and therefore, no definitive conclusions can be made about the effectiveness of these agents in children and young adults with primary high-grade osteosarcoma. Furthermore, this study was performed in a different treatment era. Nowadays single agent treatment of osteosarcoma is considered inadequate. Based on the currently available evidence, we are not able to give recommendations for the use of MTX in clinical practice. More high quality research is needed.

International collaboration is feasible in trials for rare conditions: the EURAMOS experience

The introduction of multi-agent chemotherapy dramatically improved the outcome for patients with osteosarcoma. However, we appear to have reached a plateau in outcome with a long-term event-free survival of 60-70%. Therefore, detection of further improvements will likely require larger numbers of patients. This goal is best achieved via randomized clinical trials (RCTs) requiring large-scale cooperation and collaboration. With this background, four multinational groups agreed on the merits of collaboration: Children's Oncology Group (COG), Cooperative Osteosarcoma Study Group (COSS), European Osteosarcoma Intergroup (EOI) and Scandinavian Sarcoma Group (SSG); they designed a study to determine whether altering postoperative therapy based on histological response improved the outcome. The study design includes a backbone of 10 weeks of preoperative therapy using MAP (methotrexate, Adriamycin and cisplatin). Following surgery, patients are stratified according to histological response. Patients classified as "good responders" (>or=90% necrosis) are randomized to continue MAP or to receive MAP followed by maintenance pegylated interferon, while "poor responders" (<90% necrosis) are randomized to either continue MAP or to receive MAPIE (MAP+ifosfamide, etoposide). The design includes the registration of 1,400 patients over 4 years as well as the evaluation of quality of life using two different instruments. The group has established an efficient infrastructure to ensure successful implementation of the trial. This has included the EURAMOS Intergroup Safety Desk, which has established an international system for SAE, SAR and SUSAR reporting to the relevant competent authorities and ethics committees for each participating country. The group has also developed trial site monitoring and data center audits with funding from the European Science Foundation (ESF). The ESF has also funded three training courses to familiarize institutional staff with the requirements of multinational GCP trials. We have established a successful collaboration, and as of February 2008, 901 patients have been enrolled (COG 448; COSS 226; EOI 181; SSG 46) from 249 institutions in 16 different countries. As expected, 80% of the patients are <18 years of age, and accrual into the Quality of Life sub-study is proceeding as planned with 90% of the subjects agreeing to participate. International awareness is increasing and procedures for applicant countries wishing to join the collaboration have been implemented. Details about EURAMOS can be found at www.euramos.org. International trials in rare diseases are practicable with appropriate funding, planning and support. Although the implementation of such trials is difficult and time consuming, it is a worthwhile effort to rapidly complete RCTs and identify interventions that will improve the outcome of all osteosarcoma patients.EURAMOS-1 is the fastest accruing osteosarcoma trial and is already the largest osteosarcoma study conducted.

Osteosarcoma: the European Osteosarcoma Intergroup (EOI) perspective

In the late 1970s, there was confusion regarding the best management for osteosarcoma. The benefit of chemotherapy had not been established and which chemotherapy could be used was even more uncertain. The European Osteosarcoma Intergroup (EOI) was established in order to conduct randomised studies to determine the best treatment for this tumour. Their first study 80831 established that a two drug combination of CDDP/DOX was safe and improved the survival rate over previous regimes with suboptimal chemotherapy. The CDDP/DOX was superior to a less intense CDDP/DOX/MTX regime. The second study 80861 compared the CDDP/DOX arm with a multi-drug Rosen-T10 regime. In almost 400 patients, there was the difference in outcome between the two arms. However, adherence to the protocol and completion of allocated treatment was substantially less good in the prolonged 42 week multi-drug regime compared to the two drug arm. The third study 80961 investigated interval compression i.e. if the CDDP/DOX when given every 2 weeks with GCSF superior to the same two drugs given every 3 weeks. There was no difference in survival between the arms, although there was a better histologic response rate in the compressed arm. Three randomised controlled trials on this rare disease have taken more than 20 years to accrue a sufficient sample of patients. The overall outcome has changed little in this time. Large multinational studies are needed to be able to answer these important questions in a timely fashion.

Biomarkers in Osteosarcoma

Osteosarcoma is the most common primary tumor of bone and accounts for approximately 19% of all malignant tumors of bone. It is the third most common malignant tumor in teenagers. More than twenty years ago, the advent of a multidisciplinary approach that combined multi-agent chemotherapy and limb-sparing surgery greatly improved the survival rate of patients with osteosarcoma. Unfortunately, since that time, survival rates have not dramatically improved. To date, the most powerful predictors of outcome have remained the ability to detect metastatic disease at diagnosis and the histopathologic response of the tumor to preoperative chemotherapy. Presently, 80% of patients who do not have distant metastases at initial diagnosis will become long-term survivors. Unfortunately, this means that approximately 20% of patients who do not present with metastases at diagnosis will not survive. This group of patients appears to be resistant to current treatment as attempts to intensify therapy after surgery for patients with a poor histopathologic response has not significantly improved survival rates. It is these patients that are in the greatest need of additional clinically relevant markers for prognosis and who can be most helped by molecular analysis. While steady progress has been made in the identification of genetic alterations in osteosarcoma, no individual molecular marker has thus far been demonstrated to have a better prognostic significance in the treatment of osteosarcomas than the current clinical markers. Thus there is clearly a need to employ new comprehensive analysis technologies to develop significantly more informative classification systems and to identify new therapeutic targets.

Cathepsin L inhibition suppresses drug resistance in vitro and in vivo: a putative mechanism

Cathepsin L is a lysosomal enzyme thought to play a key role in malignant transformation. Recent work from our laboratory has demonstrated that this enzyme may also regulate cancer cell resistance to chemotherapy. The present study was undertaken to define the relevance of targeting cathepsin L in the suppression of drug resistance in vitro and in vivo and also to understand the mechanism(s) of its action. In vitro experiments indicated that cancer cell adaptation to increased amounts of doxorubicin over time was prevented in the presence of a cathepsin L inhibitor, suggesting that inhibition of this enzyme not only reverses but also prevents the development of drug resistance. The combination of the cathepsin L inhibitor with doxorubicin also strongly suppressed the proliferation of drug-resistant tumors in nude mice. An investigation of the underlying mechanism(s) led to the finding that the active form of this enzyme shuttles between the cytoplasm and nucleus. As a result, its inhibition stabilizes and enhances the availability of cytoplasmic and nuclear protein drug targets including estrogen receptor-alpha, Bcr-Abl, topoisomerase-IIalpha, histone deacetylase 1, and the androgen receptor. In support of this, the cellular response to doxorubicin, tamoxifen, imatinib, trichostatin A, and flutamide increased in the presence of the cathepsin L inhibitor. Together, these findings provided evidence for the potential role of cathepsin L as a target to suppress cancer resistance to chemotherapy and uncovered a novel mechanism by which protease inhibition-mediated drug target stabilization may enhance cellular visibility and, thus, susceptibility to anticancer agents.

Expression of macrophage migration inhibitory factor relates to survival in high-grade osteosarcoma

Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is implicated in many aspects of tumor progression, including cell proliferation, invasion, and angiogenesis. We asked if MIF expression predicts survival and if it is associated with angiogenesis and cell invasion in osteosarcoma. We performed immunohistochemistry for MIF expression in prechemotherapy biopsy specimens of 58 patients with osteosarcoma. To investigate the role of MIF in angiogenesis, microvessel density was measured and compared with MIF expression. We also treated osteosarcoma cell lines (U2-OS and MG63) with MIF and measured vascular endothelial growth factor, a potent proangiogenic factor, by enzyme-linked immunosorbent assay. To study the role of MIF in cell invasion, Boyden chamber assay was performed after knockdown of MIF by short interfering RNA. MIF independently predicted overall survival and metastasis-free survival. MIF expression correlated with microvessel density and induced a dose-dependent increase in vascular endothelial growth factor. Knockdown of MIF by short interfering RNA resulted in decreased cell invasion. These results suggest MIF could serve as a prognostic marker and a potential therapeutic target for osteosarcoma.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Intraarterial chemotherapy for extremity osteosarcoma and MFH in adults

The neoadjuvant treatment of osteosarcoma using intravenous agents has resulted in survival rates of 55% to 77% [3, 5, 6, 20, 22, 35]. We designed a neoadjuvant chemotherapy protocol using combined intraarterial and intravenous agents to treat high-grade osteosarcoma and malignant fibrous histiocytoma of bone in an attempt to improve survival. We report the results of treating 53 adults (age 18-77 years) diagnosed with nonmetastatic extremity osteosarcoma or malignant fibrous histiocytoma. Preoperative chemotherapy consisted of intravenous doxorubicin followed by intraarterial cisplatinum administered repetitively every 3 weeks for three to five cycles, depending on tumor response assessed by serial arteriography. Dose and duration of cisplatin were adjusted for tumor size. After resection, good responders (90% or greater necrosis) underwent treatment with the same agents and poor responders were treated with alternative agents for longer duration. Minimum followup was 24 months (mean, 111 months; range, 24-235 months). Estimated Kaplan-Meier survival at 10 years was 82% and event-free survival was 79%. Forty-one patients (77%) had a good histologic response and 92% (49 of 53) underwent limb-sparing procedures. Local recurrence occurred in two patients (4%). These results compared favorably with those reported in the current literature.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Bone tumors in adolescents and young adults

OPINION STATEMENT

Bone tumors, particularly osteosarcomas and members of the Ewing Sarcoma Family of Tumors (ESFT), are typical malignancies of adolescents and young adults. Current diagnostic and therapeutic guidelines for patients of all ages were developed in this specific age group. The aim of bone sarcoma therapy should be to cure the patient from both the primary tumor and all (micro-)metastatic deposits while maintaining as much (extremity) function and causing as few treatment-specific late effects as possible. Bone sarcoma therapy requires close multidisciplinary cooperation. Usually, it consists of induction chemotherapy, followed by local therapy of the primary tumor (and, if present, primary metastases) and further, adjuvant chemotherapy. Local treatment for osteosarcoma should be surgery whenever feasible. Surgery is also gaining importance in ESFT, which was long considered a domain of radiotherapy. Modern reconstructive techniques continue to expand the indications for limb salvage, particularly for patients who have not yet reached skeletal maturity. Treatment within the framework of prospective, multi-institutional trials should be considered standard of care not only for children, but also for affected adolescents and (young) adults. Such trials are essential in guaranteeing that all patients have access to appropriate care and that progress from biological studies can be translated into prognostic improvements without undue delay. The rarity of bone sarcomas increasingly requires trials to be multinational.

Replacement of the hip in children with a tumor in the proximal part of the femur

BACKGROUND

Children rarely require hip replacement, and therefore very little is known about the most effective procedure for children who require hip replacement after proximal femoral resection for a tumor.

METHODS

We reviewed the outcome of forty hip replacements in children between two and fifteen years old who had a proximal femoral replacement for malignant disease. Twenty-one children survived the illness and were followed for three to twenty-one years. Cemented acetabular components were used initially to restore hip function, but, in more recent procedures, unipolar replacements and uncemented implants were used.

RESULTS

Children who were over the age of eleven years at the time of surgery had a rate of failure (defined as revision of the acetabular component) of 25% at ten years compared with a rate of 75% in younger children. Unipolar replacements in children of all ages failed by ten years, either because of pain or subluxation that led to revision. In children over the age of eleven years, both cemented and uncemented acetabular implants performed well.

CONCLUSIONS

The preferred method for restoration of hip function in children under the age of eleven years following proximal femoral resection for a tumor remains unclear. We recommend that at the initial hip surgery an attempt should be made to cause as little damage as possible to the acetabulum, but most children will inevitably need revision surgery as they get older. We hope that this study will guide others in their decision-making with regard to this relatively rare condition.

Prognostic significance of 18F-FDG uptake in primary osteosarcoma after but not before chemotherapy: a possible association with autocrine motility factor/phosphoglucose isomerase expression

Response to neoadjuvant chemotherapy is a significant prognostic factor for osteosarcoma (OS). 18-F-fluorodeoxy-D: -glucose (FDG) positron emission tomography (PET) is a noninvasive imaging modality that correlates with histological grading in musculoskeletal sarcomas. To determine the prognostic value of FDG PET in patients receiving chemotherapy, 13 patients were evaluated by FDG-PET, and followed for more than 4 years. FDG PET standardized uptake values before (SUV1) and after (SUV2) chemotherapy were analyzed and correlated with the expression of metastasis-related glycolytic enzyme, autocrine motility factor (AMF)/phosphoglucose isomerase (PGI) by immunohistochemical examination in surgically excised tumors. Although mean SUV1 for OS patients with metastatic lesions were similar to those in the completely disease-free (CDF) group (6.5 vs. 6.6, respectively, P = 0.975), mean SUV2 for OS with metastatic lesions were significantly higher than those in the CDF group (5.1 vs. 2.5, respectively, P = 0.0445). Interestingly, immunohistochemical analysis using anti-AMF/PGI antibody revealed that SUV2 correlated significantly with the AMF/PGI staining titers (P = 0.0303), while no correlation between SUV1 and the AMF/PGI staining titers existed (P = 0.964). The present study suggests that FDG PET after chemotherapy may provide information for AMF/PGI-related metastatic potentiality of residual tumors located out side of the area surgically resected afterward, and then lead to a useful prediction of the patients' prognosis.

Intravenous administration of the conditionally replicative adenovirus Ad5-Delta24RGD induces regression of osteosarcoma lung metastases

Metastatic osteosarcoma (OS) has a very poor prognosis. New treatments are therefore wanted. The conditionally replicative adenovirus Ad5-Δ24RGD has shown promising anti-tumor effects on local cancers, including OS. The purpose of this study was to determine whether intravenous administration of Ad5-Δ24RGD could suppress growth of human OS lung metastases. Mice bearing SaOs-lm7 OS lung metastases were treated with Ad5-Δ24RGD at weeks 1, 2 and 3 or weeks 5, 6 and 7 after tumor cell injection. Virus treatment at weeks 1–3 did not cause a statistically significant effect on lung weight and total body weight. However, the number of macroscopic lung tumor nodules was reduced from a median of >158 in PBS-treated control mice to 58 in Ad5-Δ24RGD-treated mice (p = 0.15). Moreover, mice treated at weeks 5–7 showed a significantly reduced lung weight (decrease of tumor mass, p < 0.05), a significantly increased body weight gain (decrease of disease symptoms, p < 0.005) and a reduced number of macroscopic lung tumor nodules (median 60 versus > 149, p = 0.12) compared to PBS treated control animals. Adenovirus hexon expression was detected in lung tumor nodules at sacrifice three weeks after the last intravenous adenovirus administration, suggesting ongoing viral infection. These findings suggest that systemic administration of Ad5-Δ24RGD might be a promising new treatment strategy for metastatic osteosarcoma.

Sarcoma

Sarcomas comprise a heterogeneous group of mesenchymal neoplasms. They can be grouped into 2 general categories, soft tissue sarcoma and primary bone sarcoma, which have different staging and treatment approaches. This review includes a discussion of both soft tissue sarcomas (malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, synovial sarcoma, dermatofibrosarcoma protuberans, angiosarcoma, Kaposi sarcoma, gastrointestinal stromal tumor, aggressive fibromatosis or desmoid tumor, rhabdomyosarcoma, and primary alveolar soft-part sarcoma) and primary bone sarcomas (osteosarcoma, Ewing sarcoma, giant cell tumor, and chondrosarcoma). The 3 most important prognostic variables are grade, size, and location of the primary tumor. The approach to a patient with a sarcoma begins with a biopsy that obtains adequate tissue for diagnosis without interfering with subsequent optimal definitive surgery. Subsequent treatment depends on the specific type of sarcoma. Because sarcomas are relatively uncommon yet comprise a wide variety of different entities, evaluation by oncology teams who have expertise in the field is recommended. Treatment and follow-up guidelines have been published by the National Comprehensive Cancer Network (www.nccn.org).

Doxorubicin and Cisplatin Regimen for High-Grade Osteosarcoma or Malignant Fibrous Histiocytoma (MFH) of the Bone

The increasing complexity of cancer chemotherapy increases the requirement that pharmacists be familiar with these highly toxic agents. This column will review various issues related to preparation, dispensing, and administration of cancer chemotherapy, and review various agents, both commercially available and investigational, used to treat malignant diseases.

Functional imaging of multidrug resistance in an orthotopic model of osteosarcoma using 99mTc-sestamibi

PURPOSE

The purpose of this work was the development of an orthotopic model of osteosarcoma based on luciferase-expressing tumour cells for the in vivo imaging of multidrug resistance (MDR) with (99m)Tc-sestamibi.

METHODS

Doxorubicin-sensitive (143B-luc(+)) and resistant (MNNG/HOS-luc(+)) osteosarcoma cell lines expressing different levels of P-glycoprotein and carrying a luciferase reporter gene were inoculated into the tibia of nude mice. Local tumour growth was monitored weekly by bioluminescence imaging and X-ray. After tumour growth, a (99m)Tc-sestamibi dynamic study was performed. A subset of animals was pre-treated with an MDR inhibitor (PSC833). Images were analysed for calculation of (99m)Tc-sestamibi washout half-life (t (1/2)), percentage washout rate (%WR) and tumour/non-tumour (T/NT) ratio.

RESULTS

A progressively increasing bioluminescent signal was detected in the proximal tibia after 2 weeks. The t (1/2) of (99m)Tc-sestamibi was significantly shorter (p < 0.05) in drug-resistant MNNG/HOS-luc(+) tumours (t (1/2) = 87.3 +/- 15.7 min) than in drug-sensitive 143B-luc(+) tumours (t (1/2) = 161.0 +/- 47.4 min) and decreased significantly with PSC833 (t (1/2) = 173.0 +/- 24.5 min, p < 0.05). No significant effects of PSC833 were observed in 143B-luc(+) tumours. The T/NT ratio was significantly lower (p < 0.05) in MNNG/HOS-luc(+) tumours than in 143B-luc(+) tumours at early (1.55 +/- 0.22 vs 2.14 +/- 0.36) and delayed times (1.12 +/- 0.11 vs 1.62 +/- 0.33). PSC833 had no significant effects on the T/NT ratios of either tumour.

CONCLUSION

The orthotopic injection of tumour cells provides an animal model suitable for functional imaging of MDR. In vivo bioluminescence imaging allows the non-invasive monitoring of tumour growth. The kinetic analysis of (99m)Tc-sestamibi washout provides information on the functional activity of MDR related to P-glycoprotein expression and its pharmacological inhibition in osteosarcoma.

Pan-European Sarcoma Trials: Moving Forward in a Climate of Increasing Economic and Regulatory Pressure

Advances in sarcoma treatment are largely based on investigator-initiated, multicentric and interdisciplinary clinical trials. The EU's Good Clinical Practice Directive 2001/20/EC, effective since 2004, was meant to harmonize the conditions for clinical trials across Europe, but, instead, the challenge of initiating and running multinational, noncommercial clinical trials has become greater than ever. Institutions participating in existing noncommercial Pan-European studies are struggling to cope with increased administrative and financial burdens, and few new studies are initiated any more. The aim of a conference entitled “Pan-European Sarcoma Trials: Moving Forward in a Climate of Increasing Economic and Regulatory Pressure,” held in Stuttgart, Germany, 30 November–2 December 2006 as part of the European Science Foundation's ECT-program, was not only to provide an overview of currently active and planned multinational studies on osteo-, Ewing's, and soft tissue sarcoma, but also to draw on areas of synergy between various established sarcoma groups in Europe to define plausible survival strategies for collaborative, interdisciplinary, patient-oriented research.