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

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.

Global protein-expression analysis of bone and soft tissue sarcomas

Analysis of global protein expression, an approach known as expression proteomics, can offer important clues for understanding tumor biology that cannot be obtained by other approaches (e.g., genome or transcriptome analysis). Using two-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry, we performed global protein expression studies of bone and soft tissue sarcomas to develop novel diagnostic and therapeutic biomarkers and allow molecular classification of the tumors. Among 1500 protein variants identified in the two-dimensional gel, 67 proteins correctly distinguished the eight subtypes of 99 histologically classified soft tissue sarcomas. Hierarchical clustering demonstrated leiomyosarcoma and MFH shared a similar protein expression profile, and clear cell sarcoma, synovial sarcoma, and MPNST could be grouped according to their protein expression patterns. Pleomorphic leiomyosarcoma and MFH showed similar tropomyosin isoform expression patterns. Patients with gastrointestinal stromal tumors expressing pfetin protein had better survival than those whose tumors lacked it. We identified 10 protein spots associated with the chemosensitivity of osteosarcoma to preoperative chemotherapy. These 10 spots could be new diagnostic and prognostic markers for osteosarcoma and new therapeutic targets for the disease. Proteomic analysis using 2D-DIGE provides novel information on the biology of bone and soft tissue sarcomas that could be used to diagnosis and treat these tumors.

LEVEL OF EVIDENCE

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

High-dose methotrexate in adults with osteosarcoma: a population pharmacokinetics study and validation of a new limited sampling strategy

Preoperative high-dose methotrexate (HD-MTX) with folinic acid (leucovorin) rescue is still a mainstay in the treatment of osteosarcoma. This anticancer agent is characterized by a narrow therapeutic index and wide interpatients variability. To ensure effective and safe administration of HD-MTX, we had earlier developed an adaptive-dosing schedule with a feedback strategy. In our institute, the MTX dosage was tailored according to individual pharmacokinetics parameters, determined in real time both from two blood samples (3.5 and 4.5 h) and from Bayesian population parameters. Up to 20 g of MTX was safely administered as 8-h infusions. Low MTX elimination rate has, however, been reported in 15-20% of the patients, and forecasting the MTX elimination phase and the management of leucovorin rescue is still a challenging issue in clinical oncology. This study aims at identifying the clinical or biological covariates related to impaired MTX clearance, and at validating a new limited sampling strategy (LSS), allowing for the accurate prediction of the MTX terminal elimination phase. This retrospective study was carried out on 49 patients (30 men, 19 women; mean age, 26.7 years) treated for osteosarcoma with HD-MTX. The population and individual pharmacokinetics parameters were computed, before the identification of the relevant covariates. Different LSSs were then tested, to predict accurately when the MTX plasma concentrations would drop below 0.2 micromol/l, the threshold associated with the end of the rescue of leucovorin with alkaline hydration. Two main covariates (creatinemia clearance and alanine aminotransferase) were correlated with MTX clearance. Conversely, the impact of body surface area on MTX pharmacokinetics was weak, suggesting that dosing schedules based on body surface area were inadequate and potentially hazardous. A new LSS predicting accurately when the MTX concentration would reach 0.2 micromol/l has been validated; blood samples are stopped as soon as the MTX concentration drops to 1 micromol/l. With this LSS, our retrospective study suggests that 60% of the patients would have left the hospital earlier than they actually did owing to a better forecasting of the MTX decrease, thus improving their quality of life while improving the cost-effectiveness for the institute. HD-MTX can be administered safely using an adaptive-dosing strategy with drug monitoring. Moreover, pharmacokinetic modeling permits the accurate forecasting of the MTX elimination profile, thus allowing for a better management of the postinfusion care of cancer patients treated with particularly high doses of this drug.

The Memorial Sloan Kettering Cancer Center experience with outpatient administration of high dose methotrexate with leucovorin rescue

BACKGROUND

We describe the safety and feasibility of an outpatient high dose methotrexate (HDMTX) regimen.

METHODS

HDMTX (12 g/m(2)) is administered in a pediatric day hospital (PDH) intravenously (IV) over 4 hrs. Urinary alkalinization is achieved using an IV bolus of sodium bicarbonate and oral bicarbonate tablets. Daily visits to the PDH follow. Leucovorin is begun 24 hrs. after MTX at a standard dose of 10 mg orally (po) every 6 hrs. (q6h). The leucovorin dose is escalated between a range of 20 mg po q6h to 1 g as a continuous IV drip over 24 hrs. according to an institutional algorithm for levels above 10, 1, and 0.1 micromol/L at 24, 48, and 72 hrs. post-MTX. To evaluate our approach, we conducted a retrospective review of all HDMTX courses administered at the Memorial Sloan Kettering Cancer Center between 1996 and 2002.

RESULTS

Out of a total of 708 MTX courses, 82% were successfully completed as an outpatient. Forty-nine percent of the MTX courses were treated with standard dose leucovorin while 49% required a dose escalation, the majority of which was to 20-30 mg po q6h. Observed toxicity included mild (Grade 0-I) nephrotoxicity and reversible transaminitis in the majority of patients. Myelosuppression was manifested mainly as neutropenia, with Grade III-IV toxicity in 16% of patients.

CONCLUSIONS

Outpatient administration of HDMTX and the required supportive therapy is safe and feasible using the described approach. Approximately half of the patients will require leucovorin dose modification based on serial monitoring of MTX levels.

Telangiectatic osteosarcoma: The St. Jude Children's Research Hospital's experience

BACKGROUND

Telangiectatic osteosarcoma (TOS) is a rare subtype of osteosarcoma (OS). The authors reviewed their experience with TOS to characterize its histologic, radiologic, and clinical features.

METHODS

The authors reviewed records, pathology material, and imaging studies from all patients with TOS who were treated between 1978 and 2005 and compared their outcomes with the outcomes of patients with all other subtypes of high-grade osteosarcoma (OS).

RESULTS

Among 323 patients with OS, 22 patients (6.8%) had TOS. Two additional patients who were treated in Chile on a recent OS trial were included. The median age at diagnosis of the 24 patients was 15.7 years. Four patients (17%) had metastatic disease, and 9 of 21 patients (43%) had pathologic fractures. Only 5 patients (who were treated after 1994) underwent limb-salvage surgery. Estimates of 5-year event-free survival (58.3% +/- 11.9%) and overall survival (66.8% +/- 11.6%) were similar to those for patients with other OS subtypes (P > or = .85). The absence of local disease progression and chemotherapy with > or =3 agents that were active against OS were correlated with improved outcome (P < or = .005). The presence of a pathologic fracture was not associated with surgery type or patient outcome.

CONCLUSIONS

TOS was associated with a high rate of pathologic fracture. With multimodality therapy, the outcome of patients with TOS was similar to that of patients with other high-grade OS subtypes. The absence of local disease progression and chemotherapy with > or =3 active agents were associated with a favorable outcome.

No correlation between methotrexate serum level and histologic response in the pre-operative treatment of extremity osteosarcoma

Our objectives were to evaluate the behavior of different doses of pre-operative methotrexate (MTX) pharmacokinetics, and assess correlations between the osteosarcoma histologic response and MTX serum peak concentrations. In total, 336 patients with osteosarcoma of the extremities were treated with three neoadjuvant protocols of chemotherapy including high-dose MTX (different doses for each protocol), cisplatin and doxorubicin (same doses in all protocols). The doses of MTX were 8 g/m2 in 124 patients, 10 g/m2 in 110 patients and 12 g/m2 in 102 patients. The mean value of peak serum MTX was 801 micromol/l (range 298-1831) with significant intra- and inter-patient variability. For patients treated with 8, 10 and 12 g/m2 it was 587, 735 and 1114 micromol/l, respectively (P < 0.0001). The histologic response to pre-operative chemotherapy was 90% or above tumor necrosis in 62.8% of patients and less than 90% in 37.2%. The grade of histologic response significantly correlated with the histologic subtype of the tumor, whereas no significant association was found between the mean peak of serum MTX and the histologic response. Thus, increasing the dose of MTX increases the MTX serum peaks, but does not correlate with the histologic response of the tumor.

Clinico-histologic parameters of osteosarcoma patients with late relapse

Primary high-grade intramedullary osteosarcoma of the extremities is a clinically aggressive bone tumour. There is an ongoing effort to further improve efficacy of neo-adjuvant chemotherapy and reduce chemotoxicity by trying to identify osteosarcoma patients who are at risk of treatment failure as well as to identify those who can do with less chemotherapy. In only 5% of patients, first distant metastasis or local relapse occurs 5 years or more after initial treatment for osteosarcoma. Patients and physicians can therefore easily erroneously consider a patient with osteosarcoma cured if he or she is disease-free for more than 5 years following diagnosis and treatment. To investigate if these rare late relapsing patients are characterised by specific clinico-pathological features, we examined clinical and histological variables of late relapse (first local recurrence or metastasis 5 years or more after initial diagnosis) out of a total of 2,243 patients, with a special interest in the histological osteosarcoma subtype. In total, 33 patients had a documented relapse 5 years or more after diagnosis. Half of the patients had good response (>or=90% necrosis) to pre-operative chemotherapy and the other half a poor response (<90% necrosis) and late relapses seemed to be more frequently proportionately in those who had a good initial response to chemotherapy. The occurrence of late relapse did not appear to be associated with age or gender. Although not statistically significant, there was a trend for patients with a chondroblastic subtype of osteosarcoma, or a location in the tibia or fibula, to have a higher risk for late relapse.

Pre- and post-chemotherapy alkaline phosphatase levels as prognostic indicators in adults with localised osteosarcoma

The prognostic value of alkaline phosphatase (AP) measured before and after chemotherapy, but before surgery was established in a retrospective survey of patients. The patients were 18 years or older, with non-metastatic high-grade osteosarcoma. Pre-chemotherapy AP was available in 89 cases, post-chemotherapy AP in 86 patients, and both in 71 cases. AP was classified as Normal (< 100% upper limit), High (100% < or = AP < 200%) or Very High (AP > or = 200%). Osteosarcoma subtype was predominantly conventional. No correlation was found between subtype and chemotherapy response, local recurrence or survival. Pre-chemotherapy AP was raised more in the osteoblastic subtype. Post-chemotherapy AP and normalisation were the same among different subtypes. AP was not correlated with local recurrence. Normal or High pre-chemotherapy AP correlated with better survival at 10 years (64% and 70%) than Very High pre-chemotherapy AP (37%, P = 0.005). Post-chemotherapy AP correlated with survival (68%, 39% and 25% in the Normal, High and Very High group, P = 0.0007) and response to chemotherapy (P = 0.049). A pre-chemotherapy AP above twice Normal correlated with worse survival. If AP decreased after chemotherapy, but was still raised, survival was better, but still worse than if AP normalised. A raised post-chemotherapy AP predicts poor chemotherapy response.

Pigment epithelium-derived factor (PEDF)-induced apoptosis and inhibition of vascular endothelial growth factor (VEGF) expression in MG63 human osteosarcoma cells

Pigment epithelium-derived factor (PEDF) has been shown to be the most potent inhibitor of angiogenesis in the mammalian eye, thus suggesting that loss of PEDF is involved in angiogenic eye diseases such as proliferative diabetic retinopathy. Angiogenesis is required for tumor growth and progression as well. We, along with others, have recently found that PEDF could inhibit growth of melanoma and hepatocellular carcinoma in nude mice through its anti-angiogenic effects on tumor endothelial cells. However, the possibility of the direct effect of PEDF on tumor cells has remained. In this study, we investigated the effects of PEDF on growth and vascular endothelial growth factor (VEGF) expression in MG63 human cultured osteosarcoma cells. PEDF decreased viable cell number as well as DNA synthesis in MG63 cells in a dose-dependent manner. Furthermore, PEDF was found to increase caspase-3/7 activity and to subsequently induce apoptotic cell death in MG63 cells. PEDF also inhibited VEGF expression in MG63 cells at both mRNA and protein levels. Our present study provides novel beneficial aspects of PEDF on osteosarcoma cells; one is induction of apoptotic cell death of tumor cells, and the other is the suppression of VEGF expression, which would lead to inhibition of tumor angiogenesis. PEDF therefore might be a promising therapeutic agent for treatment of patients with osteosarcoma.

Prognostic factors in primary central nervous system lymphomas

Efforts to identify survival predictors in primary central nervous system lymphoma (PCNSL) have produced isolated, unconfirmed observations in small retrospective and prospective series. Age and performance status are two unanimously accepted prognostic factors. These and other independent predictors of survival were used by the International Extranodal Lymphoma Study Group (IELSG) to establish a prognostic scoring system able to distinguish risk groups in PCNSL. The IELSG score will improve further with better knowledge of these malignancies, especially with the inclusion of molecular and pharmacogenetic variables able to identify lymphomas with different chemosensitivities or degrees of aggressiveness. In the years ahead, a well-established prognostic score will allow the separation of patients into risk groups, which could result in the application of risk-tailored therapeutic strategies.

Methotrexate levels and outcome in osteosarcoma

BACKGROUND

Peak serum concentrations of methotrexate (MTX) have been reported to correlate with outcome in osteosarcoma (OS). Modification of the MTX dose to achieve peak levels between 700 and 1,000 micromol/L has been recommended. The goal of the study was to assess whether there is a correlation between histologic necrosis of the tumor and/or prognosis with peak MTX serum concentration.

PROCEDURE

Treatment included multi-agent adjuvant chemotherapy, including high-dose MTX (12 g/m2). Peak MTX levels were drawn following a 4-hr infusion. Histologic evaluation for percent necrosis was done at the time of definitive resection.

RESULTS

The median peak MTX level (n = 52 patients) was 1,060 micromol/L (range: 410-4,700 micromol/L), with significant intra-patient and inter-patient variability. Fifty-eight percent of the levels were 1,000 micromol/L or higher. Response to pre-operative chemotherapy was: 18% Grade I necrosis, 35% Grade II, 31% Grade III, and 16% Grade IV. No significant association was found between the mean peak MTX levels and necrosis (P = 0.44). Event-free survival (EFS) for the 48 patients with non-metastatic disease at diagnosis was 76% at 4 years of follow-up, with no association between the mean peak MTX level and EFS (P = 0.24).

CONCLUSIONS

The absence of a demonstrable correlation between peak MTX levels and histologic necrosis or EFS may suggest that most patients achieve therapeutic levels when MTX is given at a dose of 12 g/m(2). The significant degree of intra-patient variability in peak levels poses a dilemma for pharmacokinetic adjustment. Continued use of HD-MTX in all patients, rather than dose adapted therapy, may be justified.

Tumor volume change after chemotheraphy as a predictive factor of disease free survival for osteosarcoma

Change in tumor volume after chemotherapy appears to have a prognostic significance for the outcome of osteosarcoma. A newly developed volume measurement method based on three-dimensional summation with a proved reproducibility was utilized to measure osteosarcoma tumor volume. This retrospective analysis included 38 patients with biopsy- proven, nonsurface, skeletal high-grade osteosarcoma. The treatment was started by using three cycles of preoperative chemotherapy with cisplastin (100 mg/m2) and adriamycin (30 mg/m2). The tumor volume was measured before and after preoperative chemotherapy using three-dimensional magnetic resonance image measurement. The percentage of tumor necrosis was assessed by pathologic exam. After three cycle of postoperative chemotherapy, the patients were followed up at regular interval. For the 23 good responder patients, the mean survival time was 73.2 months (95% confidence interval 61.9-84.5 months), and for the 15 poor responder patients, the mean survival time was 50.8 months (95% confidence interval 38.6-63.1 months) (p<0.05). For the 14 patients with increased tumor volume after chemotherapy, the mean survival time was 47.5 months (range: 36.3-58.6 months) and for the 24 patients with stable or decreased tumor volume, the mean survival time was 74.3 months (range: 63.79-84.88 months) (p<0.05). Among the various factors, histopathologic response and tumor volume change after chemotherapy predicted disease free survival (p<0.05). Change in the tumor volume that was measured with a reproducible method and the histopathologic response after chemotherapy were the important predictors of disease free survival for osteosarcoma patients.

Functional analysis of altered reduced folate carrier sequence changes identified in osteosarcomas

Osteosarcomas are common primary malignant bone tumors that do not respond to conventional low-dose treatments of methotrexate (Mtx), suggesting an intrinsic resistance to this drug. Previous work has shown that cDNAs generated from osteosarcoma mRNA from a fraction of patients contain sequence changes in the reduced folate carrier (RFC), the membrane protein transporter for Mtx. In this study, the functionality of the altered RFC proteins was assessed by fusing the green fluorescent protein (GFP) to the C-terminal, and examining the ability of the transfected constructs to complement a hamster cell line null for the carrier. Confocal microscopy and cell surface biotinylation indicated that all altered proteins were properly localized at the cell membrane. Only one of those examined, Leu291Pro, was unable to complement the null carrier line, but did bind Mtx at the cell surface. Thus, this alteration confers drug resistance since the carrier is unable to translocate the substrate across the cell membrane. Three alterations, Ser46Asn, Ser4Pro and Gly259Trp, while able to complement the carrier null line, conferred some degree of resistance to Mtx via a decreased rate of transport (Vmax). Another set of alterations, Glu21Lys, Ala7Val, and the combined changes Thr222Ile, Met254Thr, complemented the carrier null line and did not confer resistance to Mtx. Thus, some, but not all of these identified alterations in the RFC may contribute to the lack of responsiveness of osteosarcomas to Mtx treatment.

High-dose methotrexate pharmacokinetics and outcome of children and young adults with osteosarcoma

BACKGROUND

High-dose methotrexate (HDMTX) is used frequently in combination regimens that include nephrotoxic chemotherapy. The authors evaluated the impact of factors such as age and prior nephrotoxic agents on MTX pharmacokinetics in children and young adults with osteosarcoma and examined whether MTX pharmacokinetic parameters were associated with outcome.

METHODS

The authors evaluated MTX pharmacokinetics in 140 patients who were treated with 1083 courses of HDMTX on 3 consecutive studies of multiagent chemotherapy at a single institution. The influence of MTX pharmacokinetics on the outcome of 107 patients with localized disease was examined.

RESULTS

Mean peak MTX concentrations > or = 1000 microM were achieved in 135 patients (96%). MTX clearance was decreased after cisplatin therapy (P = 0.01), after cisplatin in combination with ifosfamide therapy (P < 0.0001), and after MTX therapy (P = 0.003). In patients with localized osteosarcoma, a higher mean MTX area under the curve, a higher mean peak concentration of MTX, a longer mean time above a threshold concentration (500 microM), and a lower mean MTX clearance were associated with lower probability of event-free survival (EFS). Patients who had a mean peak MTX plasma concentration > 1500 microM were found to have a worse outcome (estimated 5-year EFS, 58.5% +/- 6.7%) compared with patients who had a mean peak concentration < or = 1500 microM (estimated 5-year EFS, 75.5% +/- 6.6%; P = 0.02).

CONCLUSIONS

When HDMTX (12 g/m(2)) was used with multiagent therapy for patients with osteosarcoma, very high MTX exposures were associated with poorer outcome. The prospective evaluation of MTX pharmacokinetics and their relation to outcome in a large study is warranted to further substantiate the current findings and to elucidate the causative mechanism.

Outcome of flat bone sarcomas (other than Ewing's) in children and adolescents: a study of 25 cases

We analysed the clinical features and outcome of young patients with non-Ewing's flat bone sarcoma treated during the era of contemporary chemotherapy. The characteristics and outcome of 25 patients (15 males and 10 females) with primary or radiation-related flat bone sarcoma treated in the Pediatrics Department at the Institut Gustave Roussy from 1981 to 1999 were reviewed. In all, 20 patients had osteosarcoma, four chondrosarcoma and one malignant fibrous histiocytoma. The age at diagnosis ranged from 2 to 23 years (median, 15 years). Nine tumours were located in the craniofacial bones, 11 in the pelvis and five in flat bones at other sites. Four patients had metastatic disease at diagnosis. Radiation-associated flat bone osteosarcoma was diagnosed in 10 out of 25 cases. The projected overall survival and event-free survival (EFS) rates at 5 years were 45.1 and 34.3% for all the 25 patients. The EFS rate of patients with second bone sarcoma was similar to that of patients with de novo flat bone sarcoma (P=0.1). The aim of treatment was curative for 24 patients, 23 of whom were treated with intensive chemotherapy regimens and 19 with surgery. Significant adverse prognostic factors on survival included incomplete surgical resection (P=0.001) and use of regimens without pre- and postoperative chemotherapy (P=0.007). Nine of the 25 patients were treated with pre- and postoperative chemotherapy and complete surgical resection. Among them, eight are alive with no disease. Radical surgical resection is the overriding prognostic factor for flat bone sarcomas in young patients. Nevertheless, our results suggest a more favourable outcome since the advent of intensive chemotherapy.

Area under the curve of methotrexate and creatinine clearance are outcome-determining factors in primary CNS lymphomas

Although high-dose methotrexate (HD-MTX) is the most effective drug against primary CNS lymphomas (PCNSL), outcome-determining variables related to its administration schedule have not been defined. The impact on toxicity and outcome of the area under the curve (AUC(MTX)), dose intensity (DI(MTX)) and infusion rate (IR(MTX)) of MTX and plasmatic creatinine clearance (CL(crea)) was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-based combinations. Anticonvulsants were administered in 31 pts (69%). Age >60 years, anticonvulsant therapy, slow IR(MTX) (</=800 mgm(-2)h(-1)), and reduced DI(MTX) (</=1000 mgm(-2)wk(-1)) were significantly correlated with low AUC(MTX) values. Seven patients (16%) experienced severe toxicity, which was independently associated with slow CL(crea). A total of 18 (40%) patients achieved complete remission after chemotherapy, which was independently associated with slow CL(crea). In all, 22 patients were alive at a median follow-up of 31 months, with a 3-year OS of 40+/-9%; slow CL(crea) and AUC(MTX) >1100 micromol hl(-1) were independently associated with a better survival. Slow CL(crea) and high AUC(MTX) are favourable outcome-determining factors in PCNSL, while slow CL(crea) is significantly related to higher toxicity. AUC(MTX) significantly correlates with age, anticonvulsant therapy, IR(MTX), and DI(MTX). These findings, which seem to support the choice of an MTX dose >/=3 gm(-2) in a 4-6-h infusion, every 3-4 weeks, deserve to be assessed prospectively in future trials. MTX dose adjustments in patients with fast CL(crea) should be investigated.

Optimal management of methotrexate intoxication in a child with osteosarcoma

OBJECTIVE

To describe the time course and management of methotrexate (MTX) toxicity in a 14-year-old Hispanic boy with osteosarcoma treated with high-dose MTX.

CASE SUMMARY

During the sixth cycle of high-dose MTX, severe intoxication was observed with high MTX plasma concentrations, acute renal failure, and hepatitis, followed by mucositis and moderate myelosuppression. Intensification of urine alkalinization and increased leucovorin dosages did not decrease plasma concentrations of MTX or prevent systemic toxicities. Carboxypeptidase G2 and aminophylline were thus administered as a second-intention rescue strategy. Within 2 weeks, a recovery of clinical symptoms and normalization of the biological abnormalities were observed. Limb salvage surgery was performed, which permitted classifying the patient as an MTX high-responder. Thereafter, MTX was successfully resumed, leading to clinical recovery of the patient. Concomitantly, homocysteine plasma levels, a marker of the pharmacodynamic effect of MTX, were measured. During the intoxication, homocysteine plasma levels were significantly increased, parallel to the excessive MTX plasma concentrations observed.

DISCUSSION

According to the excessive MTX levels measured in this patient, along with the observed clinical (mucositis) and biological (hepatitis, renal injury) adverse effects, we suggest that MTX may be a cause of these complications. Use of the Naranjo probability scale indicated a probable relationship between the complications and MTX.

CONCLUSIONS

This observation shows that severe complications observed during one cycle of high-dose MTX is not predictive of the tolerability of further courses. Optimal management of such complications, using specific therapeutic intervention, may be considered.

Adjuvant therapy of osteosarcoma?A Phase II trial

BACKGROUND

The objective of this study was to estimate the time to treatment failure and survival rate of the three-drug combination of doxorubicin, cisplatin, and ifosfamide as primary and postoperative, adjunctive treatment for teenagers and adults with osteosarcoma (OS).

METHODS

Sixty-three eligible patients with nonmetastatic OS of the extremities were registered from 24 institutions from February, 1992 through December, 1996. Chemotherapy was comprised of doxorubicin at a dose of 75 mg/m2 and cisplatin at a dose of 120 mg/m2, alternating with doxorubicin at a dose of 50 mg/m2 and ifosfamide at a dose of 8 g/m2. Four cycles were given prior to surgical resection, and four cycles were given after surgery. Outcome measures included the time to treatment failure, overall survival, toxicity, and centralized assessment of tumor necrosis.

RESULTS

Thirty-one of 63 eligible patients died, for a 5-year overall survival rate of 58% (95% confidence interval [95% CI], 46-71%). The median time to treatment failure was 19 months (95% CI, 12-41 months). A good pathologic response (> or = 90% necrosis) to neoadjuvant chemotherapy was observed in 48% of patients who underwent surgery. There was no correlation noted between response to neoadjuvant chemotherapy and patient outcome. Grade 4 hematologic toxicities were frequent (89%), although serious nonhematologic toxicities other than nausea and emesis were uncommon.

CONCLUSIONS

The regimen and schedule used in the current study did not improve outcomes compared with prior trials of doxorubicin and cisplatin alone. New, more effective drugs are needed for the treatment of patients with OS. The identification and utilization of molecular markers to predict outcome and response to therapy would facilitate clinical management, limiting exposure to toxic therapies for patients with favorable molecular profiles and identifying those patients who may fail with current approaches as candidates for clinical trials.

Methotrexate pharmacokinetics and survival in osteosarcoma

BACKGROUND

The aim of this study was to analyze the relationship between exposure to high-dose methotrexate (HDMTX) and tumor response in terms of survival in children with osteosarcoma.

PROCEDURE

This study included 44 patients (479 courses) who received a median dose of 5.92 g/m2 of MTX (interquartile range (IQR) 2.37 g/m2) in a 4-hr infusion. The mean area under the concentration-time curve (AUC) estimated by parametric methods (non-parametric expectation maximization, NPEM), and the mean concentration at the end of the infusion were considered to be the exposure parameters. Tumor response was recorded as disease-free survival (DFS), overall survival (OS), and histologic tumor response. The relationship between MTX exposure and survival parameters was analyzed by Cox regression.

RESULTS

The group of 11 patients who were the least exposed to MTX (AUC <2,400 micromol/L hr) presented a high DFS, probably due to the shorter interval of time between MTX courses that led to a higher dose density. In patients with AUC >2,400 micromol/L hr, an increase in the AUC was related to an increase in the DFS. Significant differences were observed in the DFS between patients whose mean AUC was below or above 4,000 micromol/L hr (P=0.024), such that 4,000 micromol/L hr was considered as the minimum AUC to be aimed at for future patients.

CONCLUSIONS

Dose density seems to be an important factor in osteosarcoma response, but this must be confirmed in further studies. In order to improve the response to osteosarcoma in children, it is recommended that the dose of MTX to be increased such as to obtain an AUC higher than 4,000 micromol/L hr.

High-dose methotrexate-induced nephrotoxicity in patients with osteosarcoma

BACKGROUND

High-dose methotrexate (HDMTX)-induced renal dysfunction can be life threatening, because it delays methotrexate (MTX) excretion, thereby exacerbating the other toxicities of MTX. HDMTX-induced nephrotoxicity has been managed with high-dose leucovorin, dialysis-based methods of MTX removal, thymidine, and with the recombinant enzyme, carboxypeptidase-G2 (CPDG2), which cleaves MTX to inactive metabolites. The objectives of the current study were to estimate the current incidence of HDMTX-induced renal dysfunction in patients with osteosarcoma and to compare the efficacy and recovery of renal function for dialysis-based methods of MTX removal with treatment using CPDG2.

METHODS

The literature was reviewed for osteosarcoma trials, use of dialysis-based methods for MTX removal, and reports of MTX-induced nephrotoxicity, including information regarding recovery of renal function. Clinical trial databases of select osteosarcoma studies were reviewed. The efficacy of CPDG2 and renal recovery after CPDG2 rescue was obtained from the database of a compassionate-release trial.

RESULTS

Approximately 1.8% of patients with osteosarcoma (68 of 3887 patients) who received HDMTX developed nephrotoxicity Grade >/= 2. The mortality rate among those patients was 4.4% (3 of 68 patients). Dialysis-based methods of MTX removal were used frequently but had limited effectiveness in removing MTX compared with the rapid reductions > 98% in plasma MTX concentrations achieved with CPDG2. CPDG2 did not appear to increase the time to recovery of renal function compared with supportive treatment that included dialysis-based methods.

CONCLUSIONS

HDMTX-induced renal dysfunction continues to occur in approximately 1.8% of patients with osteosarcoma who are treated on clinical protocols with optimal supportive care. For patients with delayed MTX excretion and high plasma MTX concentrations, CPDG2 should be considered over hemodialysis to lower plasma MTX concentrations rapidly and efficiently.

A phase II study of cisplatin, doxorubicin, and ifosfamide with peripheral blood stem cell support in patients with skeletal osteosarcoma and variant bone tumors with a poor prognosis

BACKGROUND

The authors evaluated the efficacy and toxicity of cisplatin, ifosfamide, and doxorubicin with peripheral blood stem cell (PBSC) support in adult patients with osteosarcomas and variants with a poor prognosis.

METHODS

Between December 1994 and January 2001, 37 patients (20 males and 17 females) with a median age of 38 years (range, 18-63 years) entered the study. Ten patients had pelvic osteosarcomas (OS), 6 had malignant fibrous histiocytomas, 5 had metastatic OS, and 16 had miscellaneous histologies. The authors used doxorubicin (60-75 mg/m(2)) and ifosfamide (10 g/m(2)) followed by granulocyte-colony-stimulating factor (G-CSF) (5 microg/kg twice per day) for mobilization of PBSC, collected at a median of 12 days (range, 10-14 days). Three cycles with cisplatin (120 mg/m(2)), ifosfamide (10 g/m(2)), and doxorubicin (75 mg/m(2)), given 28 days apart, were planned followed by PBSC (2-4 x 10(6) CD34-positive cells/kg) infusion plus G-CSF.

RESULTS

Patients received a median of three cycles (range, one to three cycles) in addition to the mobilizing cycle. The median PBSC collection was 17.5 x 10(6)/kg (range, 13.2-90.8 x 10(6)/kg) with a median of 1 apheresis (range, 1-2 aphereses). Twenty-eight patients underwent surgery, 10 achieved 95-100% necrosis, and 4 achieved 90-94% necrosis. Six patients required early discontinuation of therapy due to toxicities, two patients developed progressive disease, and one patient was deemed unresectable. The median time to progression (TTP) and overall survival by Kaplan-Meier estimates for all 37 patients was 19 months and 49 months, respectively.

CONCLUSIONS

The authors accomplished the objective of improving the rate of necrosis with intensification of preoperative therapy. However, TTP and survival rates remained poor. The toxicity profile of this regimen is prohibitive and alternative strategies need to be investigated.

Reduced folate carrier protein expression in osteosarcoma: implications for the prediction of tumor chemosensitivity

BACKGROUND

High-dose methotrexate (MTX) is an important component of current protocols for the treatment of osteosarcoma. Although MTX uptake proceeds primarily through the reduced folate carrier (RFC) protein and efflux occurs via multidrug resistance protein 1 (MRP1), RFC protein expression in osteosarcoma remains unexamined.

METHODS

RFC and MRP1 expression (normalized to beta-actin expression) was examined with Western blot analysis in 11 osteosarcoma specimens obtained at diagnosis and 9 osteosarcoma specimens obtained on recurrence.

RESULTS

The average RFC level in specimens obtained on recurrence was significantly higher than the level in specimens obtained at diagnosis (P = 0.0005). Furthermore, in all three matched pairs of diagnosis and recurrence specimens, RFC levels were higher in recurrence specimens than in the corresponding diagnosis specimens. Potential correlations between RFC and MRP1 expression and histologic response to preoperative chemotherapy were examined. Tumors with poor histologic responses (i.e., </= 90% necrosis) had significantly lower RFC levels than did those with favorable responses to chemotherapy (P = 0.0016). In contrast, there was no correlation between MRP1 levels at diagnosis and histologic response to chemotherapy (P = 0.8764). The elevated MRP1 levels in specimens obtained on recurrence relative to MRP1 levels in specimens obtained at diagnosis were not statistically significant (P = 0.2056).

CONCLUSIONS

The significant correlation between low RFC levels at diagnosis and poor histologic response to preoperative chemotherapy suggests that RFC levels at diagnosis may be a useful predictor of chemosensitivity and warrants large-scale studies. In addition, postchemotherapy progression to recurrence is associated with a significant increase in RFC expression. To our knowledge, the current study is the first to examine RFC protein levels in tumor specimens. Cancer 2003.

Multiple primary malignancies in osteosarcoma patients. Incidence and predictive value of osteosarcoma subtype for cancer syndromes related with osteosarcoma

The overall incidence of osteosarcoma is low. However, the occurrence of osteosarcoma in a setting of multiple primary tumours is not infrequent, although population-based incidence numbers are unknown. The occurrence of osteosarcoma and other malignancies is frequently related to treatment, and can also be the result of genetic predisposition as in patients with retinoblastoma, Li-Fraumeni syndrome, Werner syndrome and Rothmund-Thomson syndrome. The aim of our study is to establish the incidence of osteosarcoma associated with other malignancies in a populationwide study and to find out if these osteosarcomas have a specific subtype, that could draw attention to a genetic predisposition to malignancy. A list of all patients registered in the Dutch National Pathology Register, named PALGA, with a diagnosis of osteosarcoma between 1975 and May 2000 was retrieved. All patients with another malignancy besides osteosarcoma were selected. All patients registered in the same period with a tonsillectomy served as a control for the occurrence of malignancy in a normal population. In a second step, only osteosarcoma patients with a history of retinoblastoma or a malignancy before the age of 46 years, since these are most probable to have a hereditary cancer syndrome, were retained for further analysis. The osteosarcomas were subtyped as common, chondroblastic, fibroblastic, teleangiectatic, anaplastic, osteoclast-rich or small cell. As a control for osteosarcoma subtypes the data of 570 patients entered in two studies from the European Osteosarcoma Intergroup (EORTC/MRC) were used. Of all 938 patients registered with the diagnosis of osteosarcoma, 66 had a history of multiple primary tumours. Four patients had a surface osteosarcoma, three an extraskeletal osteosarcoma and 59 had intramedullar high-grade osteosarcoma. Of this last group, one patient was known with Rothmund-Thomson syndrome, one had retinoblastoma and 30 had their malignancies before the age of 46. Of these 32 patients, 17 had osteosarcoma of the long bones. Especially women seem to be more susceptible for the development of multiple primaries. In nine patients, the histological subtype could be assessed by revision of available histological slides. All of these patients had an osteosarcoma subtype other than common as opposed to 29% in the control group of the European Osteosarcoma Intergroup. It is concluded that although the incidence of osteosarcoma is low, the occurrence of another malignancy in osteosarcoma patients is higher than in the normal population. Specifically, osteosarcoma patients have a relative risk of 2.4 (95% confidence interval 1.88-3.07) to develop another malignancy. A noncommon subtype of osteosarcoma should draw attention to a possible genetic predisposition of the patient involved.

The association of P-glycoprotein with response to chemotherapy and clinical outcome in patients with osteosarcoma. A meta-analysis

BACKGROUND

There is controversy regarding whether P-glycoprotein (Pgp) may be a prognostic factor for the response to chemotherapy and clinical disease progression in patients with osteosarcoma.

METHODS

The authors conducted a meta-analysis of 14 studies (n = 631 patients) that evaluated the correlation between Pgp and histologic response to chemotherapy and clinical disease progression (death, metastasis, or recurrence). Data were synthesized in receiver operating characteristic curves and with fixed-effects and random-effects likelihood ratios and risk ratios.

RESULTS

Pgp had no discriminating ability for identifying poor responders versus good responders to chemotherapy: The positive likelihood ratio was 1.15 (95% confidence interval [95% CI], 0.93-1.43), and the negative likelihood ratio was 0.88 (95% CI, 0.65-1.18; random-effects calculations). There was some between-study heterogeneity, but no study showed strong discriminating ability. Conversely, Pgp positivity increased the risk of disease progression 1.92-fold (95% CI, 1.18-3.13; random-effects calculations) with some between-study heterogeneity that disappeared when only studies that employed immunohistochemistry were considered (risk ratio, 2.23; 95% CI, 1.37-3.64). The results were robust in various sensitivity analyses, although smaller studies tended to show stronger associations with the risk of disease progression compared with larger studies (P = 0.03).

CONCLUSIONS

The available evidence showed conclusively that Pgp was not associated with the histologic response of patients with osteosarcoma to combination chemotherapy regimens. Conversely, Pgp positivity, as determined by immunohistochemistry, was a strong correlate of more rapid disease progression, although there was heterogeneity across the performed studies that, to some extent, may have reflected bias, differential measurements of Pgp, or confounding with other risk factors.

Clinical and cellular pharmacology in relation to solid tumours of childhood

Our understanding of the clinical and cellular pharmacology of drugs commonly used in the treatment of childhood cancer have increased greatly over the past two decades. However, with the exception of childhood acute lymphoblastic leukaemia (ALL), our current knowledge of factors such as inter-patient pharmacokinetic variability and cellular determinants of chemosensitivity has not been utilized in the design of integrated clinical studies. Recent pre-clinical and clinical evaluation of the topoisomerase I inhibitors topotecan and irinotecan has highlighted the potential importance of pharmacological factors in their effectiveness as cytotoxics. In this review, the clinical and cellular pharmacology of vincristine, actinomycin D, doxorubicin, cyclophosphamide, ifosfamide, cisplatin, carboplatin and etoposide will be discussed in relation to the major paediatric solid tumours. For each disease type, knowledge of the clinical and cellular pharmacology of a candidate drug will be related to pharmacodynamic responses such as response, toxicity and prognosis. For diseases such as Wilms' tumour, osteogenic sarcoma and Ewing's tumour, histological response to initial induction chemotherapy is of prognostic significance, and the depth of response is increasingly recognised as an important determinant of prognosis for high-risk neuroblastoma. For several of these tumour types, the dose-intensity of chemotherapy may be an important variable in determining prognosis. However the relationship between pharmacokinetic variability, cellular pharmacology and the major determinants of chemosensitivity to those drugs employed in first line therapy is unknown. The study of these relationships, by means of up front window studies in children who present with high-risk disease, may be as important as the introduction of new agents. Indeed, the optimisation of current therapies may be required to allow a fully informed selection of those children for whom novel therapies are truly needed. Funding and international collaboration at the clinical and scientific level would be required to achieve these aims.

Neoadjuvant chemotherapy for osteosarcoma of the extremities with metastases at presentation: recent experience at the Rizzoli Institute in 57 patients treated with cisplatin, doxorubicin, and a high dose of methotrexate and ifosfamide

BACKGROUND

Effective adjuvant or neoadjuvant regimens of chemotherapy have dramatically improved the prognosis of patients with high-grade osteosarcoma of the extremity, localized at diagnosis. Currently, little is known about patients with metastatic disease at presentation.

PATIENTS AND METHODS

From May 1995 to May 2000, 57 patients with osteosarcoma of the extremity, metastatic at presentation, were treated according to the following scheme: primary chemotherapy, restaging, simultaneous resection of primary tumor and metastatic lesions, and maintenance chemotherapy.

RESULTS

Thirty-five patients achieved remission. At a follow-up ranging from 2 to 7 years, seven remained continuously free of disease, one died of chemotherapy-related toxicity and 27 patients relapsed. Twenty-one of the 22 patients who never achieved remission died as a result of the tumor, as well as 20 of the 27 who achieved remission but then relapsed. Of the remaining seven relapsing patients, six are alive with uncontrolled disease, while one is alive and free of disease 24 months after the last post-relapse treatment. Two-year event-free survival (EFS) and overall survival (OS) were 21% and 55%, respectively. These results are significantly poorer than those achieved in 128 contemporary patients with non-metastatic disease at presentation, treated with the same chemotherapy protocol (2-year EFS and OS of 75% and 94%, respectively).

CONCLUSIONS

The results of our study confirm that the prognosis of patients with osteosarcoma of the extremity, metastatic at presentation, remains poor, despite the use of aggressive treatments.

Neoadjuvant chemotherapy for high-grade central osteosarcoma of the extremity. Histologic response to preoperative chemotherapy correlates with histologic subtype of the tumor

BACKGROUND

In primary central high-grade osteosarcoma, a number of distinct subtypes have been identified, but little is known about the response to chemotherapy.

METHODS

The authors investigated whether the subtypes correlated with histologic response to chemotherapy in 1058 patients with osteosarcoma of the extremities who were treated with neoadjuvant chemotherapy over the last 20 years. The tumors were classified as osteoblastic (70%), chondroblastic (13%), fibroblastic (9%), and telangiectatic (6%). At diagnosis, 911 patients had localized disease and 147 had resectable lung metastases.

RESULTS

The response to preoperative chemotherapy was good (90% or more tumor necrosis) in 59% of patients and poor (< 90% tumor necrosis) in 41% of patients. The rate of good responses was significantly higher (P = 0.0001) in the fibroblastic (83%) and telangiectatic (80%) tumors and significantly lower in chondroblastic tumors (43%). Prognosis was significantly correlated with the histologic subtypes. The 5-year overall survival rate was significantly higher (P = 0.0001) in fibroblastic (83%) and telangiectatic (75%) tumors than in osteoblastic (62%) and chondroblastic (60%) tumors. In all subtypes, except for the chondroblastic subtype, the 5-year overall survival rate was significantly higher (P = 0.0001) in good responders P = 0.0001 (68%) than in poor responders (52%).

CONCLUSIONS

The authors concluded that the histologic subtype of primary central high-grade osteosarcoma of the extremity was strictly correlated with histologic response to chemotherapy and probably, as a consequence, also with prognosis. Further studies are needed to establish whether these results justify a specific therapeutic approach based on the histologic subtype of the tumor.

Genetic and epigenetic alterations of the cell cycle regulators and tumor suppressor genes in pediatric osteosarcomas

PURPOSE

To analyze the genetic and epigenetic alterations affecting the RB1, TP53, p16INK4, and p21WAF1 tumor suppressor genes, loss of heterozygosity (LOH) at 3q and 18q, and the clinical variables of a series of Spanish children with osteosarcoma. These genetic changes were tested for an association with prognosis.

METHODS

Peripheral blood samples and clinical data were available from 76 patients with osteosarcoma. Paired tissue was available from 41 of them. The mutation and methylation status of p16INK4, p21WAF1, TP53, and RB1 was screened as well as LOH at 3q and 18q.

RESULTS

Loss of heterozygosity affecting RB1 (37.2%), TP53 (42.3%), and 18q (30.8%) and TP53 mutation (39%) were frequently encountered. TP53 mutation was associated with diagnosis at a later age. RB1 alteration was associated with reduced survival and event-free survival. The clinical variables associated with poor prognosis were the presence of metastasis at diagnosis (P = 0.035) or during treatment (P = 0.016) and the chondroblastic histologic subtype (P = 0.007); the response to induction chemotherapy (<90% necrosis) also tended to be related to poor prognosis (P = 0.08).

CONCLUSIONS

RB1, TP53, and possibly other tumor suppressor genes located at 18q and other localizations are involved in pediatric osteosarcoma carcinogenesis, together with other genetic alterations not fully understood to date. Based on these results, the presence of an altered RB1 gene should be regarded as a poor prognostic factor for pediatric osteosarcoma.

Bayesian estimation of methotrexate pharmacokinetic parameters and area under the curve in children and young adults with localised osteosarcoma

BACKGROUND

Methotrexate is the most efficient anticancer drug in osteosarcoma. It requires individual exposure monitoring because of the high doses used, its wide interpatient pharmacokinetic variability and the existence of demonstrated relationships between efficacy, toxicity and serum drug concentrations.

OBJECTIVE

To develop a maximum a posteriori (MAP) Bayesian estimator able to predict individual pharmacokinetic parameters and exposure indices such as area under the curve (AUC) for methotrexate from a few blood samples, in order to prevent toxicity and facilitate further studies of the relationships between efficacy and exposure.

METHODS

Methotrexate population pharmacokinetics were estimated by a retrospective analysis of concentration data from 40 children and young adults by using the nonparametric expectation maximisation method NPEM. A linear two-compartment model with elimination from the central compartment was assumed. Individual pharmacokinetic parameters and AUC were subsequently estimated in 30 other young patients, using MAP Bayesian estimation as implemented in two programs, ADAPT II and an inhouse program Winphar((R)).

RESULTS

The pharmacokinetic parameters used in the model were the volume of the central compartment (V(1)) and the transfer constants (k(10), k(12) and k(21)). The mean values (with percentage coefficient of variation) obtained were: 18.24L (54.1%) and 0.41 (42.3%), 0.0168 (68.7%), and 0.1069 (61.3%) h(-1), respectively. Bayesian forecasting enabled nonbiased estimation of AUC and systemic clearance using a schedule with two sampling times (6 and 24 hours after the beginning of the infusion) and either program. Collection of a third sample at 4 hours improved the precision.

CONCLUSION

The Bayesian adaptive method developed herein allows accurate estimation of individual exposure to methotrexate and can easily be used in clinical practice.

Early blast clearance by remission induction therapy is a major independent prognostic factor for both achievement of complete remission and long-term outcome in acute myeloid leukemia: data from the German AML Cooperative Group (AMLCG) 1992 Trial

Risk assessment in acute myeloid leukemia (AML) using pretreatment characteristics may be improved by incorporating parameters of early response to therapy. In the 1992 trial of the German AML Cooperative Group (AMLCG), the amount of residual leukemic blasts in bone marrow was assessed one week after the first induction course (day 16 blasts). A total of 449 patients 16 to 76 years of age (median, 53 years) with de novo AML entered the trial and were evaluable. Treatment included TAD/HAM (thioguanine, cytosine arabinoside, and daunorubicin/high-dose cytosine arabinoside and mitoxantrone) double induction, TAD consolidation, and randomly either maintenance therapy or S-HAM consolidation. Cytogenetics were favorable, intermediate, unfavorable and not available in 10.0%, 48.3%, 13.1%, and 28.5%, respectively. Day 16 blasts ranged from 0% to 100% (median, 5%, mean +/- SD, 18.6 +/- 28.5%). Complete remission (CR) rate was 72.6%, 17.6% had persistent leukemia (PL), and 9.8% succumbed to hypoplastic death. Median overall survival (OS), event-free survival (EFS), and relapse-free survival (RFS) were 18, 9, and 15 months with 28.4%, 21.6%, and 30.1% at 5 years, respectively. As a continuous variable, day 16 blasts were related to CR rate (P < 0.0001), PL rate (P < 0.0001), OS (P < 0.0001), EFS (P < 0.0001), and RFS (P = 0.0049). Multivariate analyses identified the following parameters to be associated with the respective end points. CR rate: day 16 blasts (P <.0001), age (P =.0036), and LDH (P =.0072); OS: unfavorable cytogenetics (P <.0001), day 16 blasts (P <.0001), age (P <.0001), and LDH (P =.0040); EFS: unfavorable cytogenetics (P <.0001), LDH (P <.0001), day 16 blasts (P <.0001), and age (P =.0061); RFS: unfavorable cytogenetics (P <.0001), LDH (P <.0001), and day 16 blasts (P =.0359). The prognostic significance of day 16 blasts is independent of pretherapeutic parameters and predicts outcome even in patients achieving a CR.

Application of pharmacokinetic modelling to the routine therapeutic drug monitoring of anticancer drugs

Over the last 10 years, proofs of the clinical interest of therapeutic drug monitoring (TDM) of certain anticancer drugs have been established. Numerous studies have shown that TDM is an efficient tool for controlling the toxicity of therapeutic drugs, and a few trials have even demonstrated that it can improve their efficacy. This article critically reviews TDM tools based on pharmacokinetic modelling of anticancer drugs. The administered dose of anticancer drugs is sometimes adjusted individually using either a priori or a posteriori methods. The most frequent clinical application of a priori formulae concerns carboplatin and allows the computation of the first dose based on biometrical and biological data such as weight, age, gender, creatinine clearance and glomerular filtration rate. A posteriori methods use drug plasma concentrations to adjust the subsequent dose(s). Thus, nomograms allowing dose adjustment on the basis of blood concentration are routinely used for 5-fluorouracil given as long continuous infusions. Multilinear regression models have been developed, for example for etoposide, doxorubicin. carboplatin, cyclophosphamide and irinotecan, to predict a single exposure variable [such as area under concentration-time curve (AUC)] from a small number of plasma concentrations obtained at predetermined times after a standard dose. These models can only be applied by using the same dose and schedule as the original study. Bayesian estimation offers more flexibility in blood sampling times and, owing to its precision and to the amount of information provided, is the method of choice for ensuring that a given patient benefits from the desired systemic exposure. Unlike the other a posteriori methods, Bayesian estimation is based on population pharmacokinetic studies and can take into account the effects of different individual factors on the pharmacokinetics of the drug. Bayesian estimators have been used to determine maximum tolerated systemic exposure thresholds (e.g. for topotecan or teniposide) as well as for the routine monitoring of drugs characterized by a very high interindividual pharmacokinetic variability such as methotrexate or carboplatin. The development of these methods has contributed to improving cancer chemotherapy in terms of patient outcome and survival and should be pursued.

Does the histological subtype of high-grade central osteosarcoma influence the response to treatment with chemotherapy and does it affect overall survival? A study on 570 patients of two consecutive trials of the European Osteosarcoma Intergroup

Large randomised trials are mandatory when one wants to examine the effects of different aspects (such as the treatment modality) of a pathological condition on the overall outcome. This is especially true when studying a disease in which there is a multifactorial influence on progression and outcome such as osteosarcoma. Data on 570 patients with biopsy-proven primary central osteosarcoma of an extremity included in two consecutive studies of the European Osteosarcoma Intergroup (EOI) were analysed in order to evaluate if the histological subtype of the biopsy specimen correlated with the subtype of osteosarcoma represented in the resected specimen, if there was a relationship between the histological subtype and overall survival and if there was a relationship between the histological subtype and histological response to chemotherapy. High-grade osteosarcoma, as defined by established criteria, was subtyped as either conventional, chondroblastic, teleangiectatic, small cell, fibroblastic, osteoclast rich, anaplastic and sclerotic/osteoblastic well differentiated. A panel of experienced pathologists with a special interest in bone pathology was appointed to review the histological diagnosis and to assess the tumour response to chemotherapy on the resected specimen of each patient entered into the trials. Subtyping on the biopsy specimen proved to be highly representative for the subtype of the whole tumour. In 102 patients for which subtyping was performed on the biopsy and the resected specimens, there were only two discrepancies. Of the 568 patients for whom subtype was available, 404 (71%) were of the conventional type, 54 (10%) were chondroblastic, 53 (9%) had fibroblastic tumours and the remainder consisted of rare subtypes. A good response to preoperative chemotherapy was defined as 90% or more necrosis. The proportion of patients responding well to chemotherapy differed significantly between subtypes (Chi-square test statistics=11.44, P=0.01 on 3 degrees of freedom (d.f.)). In comparison with the conventional subtype, there was a higher proportion of good responders in the fibroblastic group and a lower proportion of good responders in the chondroblastic group. Good responders had a significantly better survival than patients who responded poorly to the pre-operative chemotherapy (logrank statistic=25.20, P<0.01 on 1 df). Survival did not differ significantly according to subtype (logrank statistic=2.72, P=0.44 on 3 df), although there was a suggestion that patients with chondroblastic tumours experienced a better long-term survival. This large set of prospectively-collected data provides important information on the relationship between pathological subtype, histological response and survival. Histological response has a known prognostic effect on survival, and we have shown that the rates of response differ by subtype. There is some evidence from this study that the specific histological subtypes, i.e. the chondroblastic subtype, experience better survival. However, despite this large multi-institutional study, we have insufficient numbers of non-conventional tumours to examine this unambiguously for these subsets.

High-dose chemotherapy in the treatment of relapsed osteosarcoma: an Italian sarcoma group study

PURPOSE

To study the feasibility and activity of two courses of high-dose chemotherapy (HDCT) in patients with osteosarcoma in metastatic relapse.

PATIENTS AND METHODS

Patients with high-grade osteosarcoma in metastatic relapse (multiple metastases or solitary metastasis at intervals of less than 30 months) were eligible for study. High-dose chemotherapy consisted of carboplatin and etoposide followed by stem-cell rescue. A second course was planned 4 to 6 weeks after the first. Surgery was performed before or after HDCT.

RESULTS

Thirty-two patients were enrolled onto the study. At the end of the treatment, 25 patients were in complete remission (CR), six were alive with disease progression, and one died of toxicity. At present, 14 patients are alive with a median survival time of 23 months from study entry: four are in first CR, three are in second CR, and one is in fourth CR. Six patients are alive with disease. Eighteen patients (56%) died: 17 of disease and one of toxicity. Transplantation-related mortality was 3.1%. The relapse or progression disease rate was 84.4%. The 3-year overall survival rate is 20% and the 3-year disease-free survival rate is 12%.

CONCLUSION

HDCT combined with surgery is feasible and can induce CR in a large portion of patients. Two points, however, need to be considered: only patients who are chemosensitive to induction treatment can obtain CR after HDCT, and the length of remission is short, because most patients relapse. Thus novel strategies are needed to maintain the remission status or to treat patients who do not respond to induction treatment.

High dose ifosfamide in combination with high dose methotrexate, adriamycin and cisplatin in the neoadjuvant treatment of extremity osteosarcoma: preliminary results of an Italian Sarcoma Group/Scandinavian Sarcoma Group pilot study

With the intention of starting an international protocol between Italy and Scandinavia on neoadjuvant treatment of extremity osteosarcoma using the four active drugs at maximum doses (doxorubicin 75 mg/m2 pre-operatively, and 90 mg/m2 post-operatively, cisplatin 120 mg/m2, methotrexate 12 g/m2, and ifosfamide 15 g/m2), a single center (the Rizzoli institute) performed a pilot study to closely monitor toxicity, safety, and tumor necrosis. Only 7 patients (10%) had a reduced number of the scheduled cycles. A total of 1,050 of the expected 1,076 cycles (98%) were administered. Delays and dose reduction were minimal, leading to a mean received dose intensity of 89%. Limb salvage surgery was performed in 59 cases (87%), with 6 amputations and 3 rotation plasties. Chemotherapy-induced necrosis higher than 95% was observed in 38 patients (56%). Eleven patients had total necrosis (16%). At a median follow-up of 60 months (range 50-65 months), 53 patients (73%) were continuously disease-free. Six of the relapsed patients were rescued with further treatments leading to an overall survival of 87%. Hematological toxicity was remarkable despite the use of G-CSF and hospitalization due to febrile neutropenia occurred in 25 patients (37%). Platelet transfusions were required in 77 of the 194 episodes of grade 4 thrombocytopenia, but no case of major bleeding was observed. Red blood cell transfusions were necessary in all patients (in 15 cases perioperatively only). Non-hematological toxicity comprised grade 1-2 nephrotoxicity in 3 cases, CNS toxicity in 2 cases, and dilata- tive cardiopathy leading to heart transplantation in 1 case. In conclusion, the pilot study was feasible in the vast majority of cases with toxicity not superior to that of the previous protocols where chemotherapy was given in lower doses. The rate of limb salvage procedures, event-free survival and overall survival seemed to be higher than in previous protocols. On the basis of this study, in March 1997 the Italian and Scandinavian Sarcoma Groups started a new protocol for osteosarcoma of the extremities.

VCP (p97) regulates NFkappaB signaling pathway, which is important for metastasis of osteosarcoma cell line

In order to identify genes associated with metastasis, suppression subtractive hybridization (SSH) was performed using murine osteosarcoma cell line Dunn and its subline with higher metastatic potential, LM8. SSH revealed expression of the gene encoding valosin-containing protein (VCP; also known as p97) to be constitutively activated in LM8 cells, but it declined in Dunn cells when the cells became confluent. Because VCP is known to be involved in the ubiquitination process of Inhibitor-kappaBalpha (IkappaBalpha), an inhibitor of nuclear factor-kappaB (NFkappaB), whether VCP influences NFkappaB activation or not was examined by using VCP-transfected Dunn cells (Dunn/VCPs). When stimulated with tumor necrosis factor-alpha (TNFalpha), Dunn/VCPs showed constantly activated NFkappaB, although in the original Dunn cells and control vector transfectant (Dunn/Dunn-c) NFkappaB activation ceased when the cells became confluent. Western immunoblot analysis showed an increase of phosphorylated IkappaBalpha (p-IkappaBalpha) in the cytoplasm of confluent Dunn/Dunn-c cells compared to that of Dunn/VCPs. Therefore, decrease of p-IkappaBalpha degrading activity might be responsible for the decrease in NFkappaB activation. In vitro apoptosis assay demonstrated increased apoptosis rates of Dunn/Dunn-c cells after TNFalpha stimulation compared to those of Dunn/VCPs and LM8 cells. In vivo metastasis assay showed increased incidences of metastatic events in Dunn/VCP-1 inoculated male C3H mice compared to those in Dunn/Dunn-c inoculated mice. These findings suggested that VCP expression plays an important role in the metastatic process. Anti-apoptotic potential in these cells owing to constant NFkappaB activation via efficient cytoplasmic p-IkappaBalpha degrading activity may explain the increased metastatic potential of these cells.

Prognostic factors in high-grade osteosarcoma of the extremities or trunk: an analysis of 1,702 patients treated on neoadjuvant cooperative osteosarcoma study group protocols

PURPOSE

To define prognostic factors for response and long-term outcome for a wide spectrum of osteosarcomas, extending well beyond those of the typical young patient with seemingly localized extremity disease.

PATIENTS AND METHODS

A total of 1,702 consecutive newly diagnosed patients with high-grade osteosarcoma of the trunk or limbs registered into the neoadjuvant studies of the Cooperative Osteosarcoma Study Group before July 1998 were entered into an analysis of demographic, tumor-related, and treatment-related variables, response, and survival. The intended therapeutic strategy included preoperative and postoperative chemotherapy with multiple agents as well as surgery of all operable lesions.

RESULTS

Axial tumor site, male sex, and a long history of symptoms were associated with poor response to chemotherapy in univariate and multivariate analysis. Actuarial 10-year overall and event-free survival rates were 59.8% and 48.9%. Among the variables assessable at diagnosis, patient age (actuarial 10-year survival > or = 40, 41.6%; < 40, 60.2%; P =.012), tumor site (axial, 29.2%; limb, 61.7%; P <.0001), and primary metastases (yes, 26.7%; no, 64.4%; P <.0001), and for extremity osteosarcomas, also size (> or = one third, 52.5%; < one third, 66.7%; P <.0001) and location within the limb (proximal, 49.3%; other, 63.9%; P <.0001), had significant influence on outcome. Two additional important prognostic factors were treatment related: response to chemotherapy (poor, 47.2%; good, 73.4%; P <.0001) and the extent of surgery (incomplete, 14.6%; macroscopically complete, 64.8%; P <.0001). All factors except age maintained their significance in multivariate testing, with surgical remission and histologic response emerging as the key prognostic factors.

CONCLUSION

Tumor site and size, primary metastases, response to chemotherapy, and surgical remission are of independent prognostic value in osteosarcoma.

Adjuvant chemotherapy for osteosarcoma may not increase survival after neoadjuvant chemotherapy and surgical resection

BACKGROUND AND OBJECTIVES

Osteosarcoma is a primary malignancy of bone. Current therapy includes neoadjuvant chemotherapy, surgery, and postoperative (adjuvant) chemotherapy. Prolonged treatment with chemotherapeutic agents may place patients at increased risk for complications including secondary malignancy. The authors have had promising results with neoadjuvant therapy and surgery alone in the treatment of osteosarcoma. This study retrospectively examines neoadjuvant therapy and surgery alone for the treatment of primary osteosarcoma of bone with no evidence of distant metastases.

METHODS

Fifty-four patients, with localized osteosarcoma of bone received neoadjuvant therapy followed by definitive surgical resection. Thirty-five patients received chemotherapy after surgery (adjuvant group) and nineteen patients were followed without postoperative chemotherapy (no adjuvant group).

RESULTS

Tumor necrosis was predictive of survival. Kaplan-Meier analysis revealed the use of postoperative chemotherapy was not a predictor of improved outcome. Four patients in the adjuvant therapy group died of secondary malignancy compared with none of the no adjuvant therapy group. Patient age, sex, race, and tumor location were not predictive of survival.

CONCLUSIONS

The use of adjuvant chemotherapy in the treatment of localized osteosarcoma of bone did not increase survival after neoadjuvant therapy and definitive surgical therapy. Instead, there was an increased incidence of secondary malignancy after its use.

In vivo inhibition of tumour growth by dexamethasone in murine osteosarcomas

This study was performed to determine whether glucocorticoid (GC) is an effective inhibitor of tumour growth in murine osteosarcoma (OS) in vivo. The effects of dexamethasone (DEX) on the growth of this tumour were studied in male C3H/He mice. The animals received a dose of 1.25 or 5 microg/g of DEX in 0.1 ml of steroid solution daily intraperitoneally (i.p.) for 14 days. In each DEX-treated group, significant inhibition of the tumour growth curve was seen in a dose- dependent manner compared with the control group (P<0.0001). The percentage of proliferative cell nuclear antigen (PCNA)-positive cells was 22.7% in the 5 microg/g DEX treatment group compared with 67.6% in the control group (P=0.009). Furthermore, mifepristone, a GC receptor antagonist, blocked the inhibition of tumour growth induced by DEX. In the control group, tumour cells showed positive reactivity for nuclear glucocorticoid receptors (GR) by immunohistochemistry. The results of this study indicate that tumour growth inhibition by DEX in murine osteosarcoma may be via GR.

Current treatment of osteosarcoma

A comprehensive multidisciplinary approach has transformed osteosarcoma from a disease with a modest long-term survival to one in which at least two-thirds of patients will be cured. Surgery remains the vital modality for treating the primary tumor, whereas adjuvant chemotherapy plays an essential role in the control of subclinical metastatic disease. Complete surgical excision of the primary tumor remains an essential element of treatment. For many patients, a combination of advances in surgical technique, improved imaging modalities to accurately document tumor extent, and the effect of neoadjuvant chemotherapy has made limb salvage procedures a safe alternative to amputation. In some patients for whom complete surgical excision is impossible, the addition of radiation therapy may allow local tumor control. The most effective chemotherapy agents currently in use include high-dose methotrexate, doxorubicin, cisplatin, and ifosfamide/etoposide. The optimal schedule of therapy is still being investigated, as is the role of dose intensification. Unfortunately, some groups of patients remain at high risk of eventual relapse. Those whose tumors show relatively low degrees of necrosis after administration of chemotherapy have poorer survival than patients with more chemotherapy-responsive tumors. Similarly, patients who present with overt metastatic disease (particularly bone metastases), as well as patients with tumors that recur after treatment, continue to have an unsatisfactory outcome. These groups, in particular, may benefit from future investigations into novel agents, such as biological response modifiers, antiangiogenesis factors, and growth receptor modulation.

Histologic response of high-grade nonmetastatic osteosarcoma of the extremity to chemotherapy,

In 510 patients with osteosarcoma of the extremity treated at the authors' institute between March 1983 and June 1995 with different regimens of neoadjuvant chemotherapy, factors that influenced the histologic response were investigated. The rate of total necrosis was not related to the patients' gender, age, site, size of tumor, serum of alkaline phosphatase values, or route of cisplatin administration. The histologic response significantly and independently correlated with the number of drugs administered before surgery and with the histologic subtype of the tumor. According to the number of drugs used, the percentage of total necrosis was 31% for a four-drug regimen, 18% for a three-drug regimen, and only 1.5% for a two-drug regimen. According to the histologic type, the rates of total necrosis were 41% for telangiectatic tumors, 36% for fibroblastic tumors, 15% for osteoblastic tumors, and 3% for chondroblastic tumors. The authors concluded that in neoadjuvant therapy of osteosarcoma, the histologic response to preoperative treatment, which correlates with prognosis, depends on the effectiveness of the chemotherapy regimen and on some features intrinsically inherent to the tumor. These data should be considered when selecting the type of treatment (adjuvant or neoadjuvant) and the combinations of drugs to be used in preoperative treatment of patients with osteosarcoma.

Antioxidants inhibit TNFalpha-induced motility and invasion of human osteosarcoma cells: possible involvement of NFkappaB activation

Osteosarcoma is the most frequent malignant bone tumor in children. It is highly invasive, however, the mechanisms behind osteosarcoma cell invasion are as yet still unknown. In the present study, treatment with TNFalpha enhanced the invasiveness of two human osteosarcoma cell lines, OST and MNNG. TNFalpha treatment also induced tumor cell motility, adhesion to laminin, the expression of matrix metalloproteinase 9 (MMP9), and the nuclear translocation of nuclear factor kappaB (NFkappaB) in the osteosarcoma cells. Moreover, antioxidants inhibited TNFalpha-induced osteosarcoma cell invasion, motility and NFkappaB nuclear translocation, but not adhesion to laminin or MMP9 expression. NFkappaB decoy, another NFkappaB inhibitor, also inhibited TNFalpha-induced osteosarcoma cell invasion and motility. Therefore, motility and NFkappaB activation were possibly related to TNFalpha-induced osteosarcoma cell invasion. However, adhesion to laminin or MMP did not demonstrate any correlation with TNFalpha-induced osteosarcoma cell invasion. Although NFkappaB is known to regulate TNFalpha-induced phenotypes, it may influence only motility and invasion, but not the MMP or laminin-mediated adhesion of these osteosarcoma cells.

Reconstruction of the proximal humerus with the clavicle after tumor resection: a case report

Reconstruction of the proximal humerus after resection for tumor and modification of the clavicular transposition procedure is described in which the blood supply of the clavicle is preserved and the clavicle is used to bridge the defect. An 11-year-old boy presented with shoulder pain, and the diagnosis was osteosarcoma of the right proximal humerus. After resection of the sarcomatous proximal humerus, the clavicle was released with its periosteum remaining intact, and the clavicle was rotated downward around the acromioclavicular joint. A vascularized fibula supplemented the reconstruction in trying to gain length of the arm. The acromioclavicular joint and the vascular supply of the clavicle were preserved. Internal fixation from the clavicle and the fibula to the distal humerus was made with an AO plate and screws. Muscles around the proximal humerus were reattached to the clavicle. Range of motion of the shoulder was 80 degrees flexion, 85 degrees abduction, 30 degrees external rotation, and 90 degrees internal rotation. Although the postoperative followup is relatively short, only 2 years, the functional advantages of this operation over other forms of reconstruction can be observed.

Tumor volume change as a predictor of chemotherapeutic response in osteosarcoma

The change in osteosarcoma tumor volume after preoperative adjuvant chemotherapy and its relationship to the histopathologic response was investigated using various reproducible volumetric methods. Tumor volume was measured before and after chemotherapy in 41 patients with osteosarcoma using an ellipsoid formula in plain radiography and magnetic resonance imaging and three-dimensional magnetic resonance imaging measurement. Based on intraobserver and interobserver variability for the volumetric measurements of each method, three-dimensional magnetic resonance imaging measurement was the most reproducible. In three-dimensional magnetic resonance measurements, the correlation of the histopathologic response with absolute and relative total tumor volume changes and extraosseous volume change were significant. The good responder group showed a greater reduction in tumor volume after chemotherapy, although there was no significant difference in pretreatment tumor volume between the good and poor responder groups. The group with a decreased or stable tumor volume represented a good histopathologic response with a sensitivity of 85%, specificity of 76%, and positive predictive value of 88%. The change in tumor volume of osteosarcoma measured by three-dimensional magnetic resonance imaging could predict histopathologic response after three cycles of neoadjuvant chemotherapy.

Interleukin-12 induces efficient lysis of natural killer-sensitive and natural killer-resistant human osteosarcoma cells: the synergistic effect of interleukin-2

Previously we demonstrated that some osteosarcoma cell lines varied greatly in their susceptibility to natural killer (NK) cell lysis in vitro. The expression of CD54 and CD58 adhesion molecules on their surface appeared to influence their vulnerability, and the tumour necrosis factor-alpha (TNF-alpha)-induced positive modulation of CD54 increased osteosarcoma susceptibility in vitro. This study investigated whether peripheral blood mononuclear cells from normal healthy donors could be activated by interleukin (IL)-12 and IL-2, separately or in combination, to lyse osteosarcoma cell lines in vitro, as evaluated by using a microcytotoxicity test. In addition, we analysed (by flow cytometry) whether this function correlated with modifications of the CD2, CD11a, CD11b and CD18 molecules, which are involved in the adhesion of effector cells to the counter-receptors (CD54 and CD58) on osteosarcomas. This study demonstrates that incubation with IL-12 and/or IL-2 triggered NK cell cytolytic activity against osteosarcoma targets and that cytolytic activity was enhanced to a greater extent when lymphocytes were incubated simultaneously with a combination of IL-12 and IL-2. The density of CD18 and CD2 molecules involved in NK adhesion was also up-modulated following cytokine incubation. These changes in the density of adhesion molecules can be involved in the increased lytic activity of effector lymphocytes and in the modification of their binding capacity to osteosarcoma target cells.