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Epidemiology of osteosarcoma and Ewing's sarcoma in childhood: a study of 305 cases by the Children's Cancer Group.

BACKGROUND: The Children's Cancer Group conducted a case-control study to determine the role of a broad range of environmental and familial factors in the etiology of Ewing's sarcoma and osteosarcoma in children. These factors included radiation exposure and, for children with osteosarcoma, parental exposure to beryllium. METHODS: The parents of 152 children with osteosarcoma and 153 children with Ewing's sarcoma were interviewed by telephone. Controls were obtained by random digit dialing and were matched to cases by age and race. RESULTS: Female osteosarcoma patients had earlier onset of breast development (age 11.4 vs. 11.8 years, P=0.03) and menarche (age 12.1 vs. 12.5 years, P=0.002) but no significant differences in growth, whereas male osteosarcoma patients were similar in age at the onset of secondary sexual characteristics but reported significantly less weight gain during their growth spurt (6.6 vs. 11.7 kg, P=0.003). For children with Ewing's sarcoma, the growth spurt began earlier (age 12.1 vs. 12.7 years, P=0.12) and resulted in less weight and height gain (5.2 vs. 9.7 kg, P=0.002, and 10.2 vs. 12.7 cm, P=0.02, respectively) for males, but no differences were observed among females. For factors not related to growth and development (including a wide range of occupational, medical, and household exposures), there was little evidence of an etiologic role with respect to either tumor type. CONCLUSIONS: Differences between cases and controls with respect to growth and development showed no consistent pattern. This study did not identify any important risk factors for either type of childhood bone tumor.

Adolescent↗

Imaging assessment of the responses of osteosarcoma patients to preoperative chemotherapy: angiography compared with thallium-201 scintigraphy.

BACKGROUND: Assessment of the responses of osteosarcoma patients to preoperative chemotherapy is of clinical importance. The purpose of this study was to estimate the accuracy of angiography and thallium-201 scintigraphy, compared with histology, in assessing the responses of patients with osteosarcoma to preoperative chemotherapy. METHODS: Nineteen patients with osteosarcoma who were diagnosed between 1992 and 1997 were studied. The findings of angiography and thallium-201 scintigraphy before and after preoperative chemotherapy were compared with the percentage of necrosis of tumor cells and the response grade as determined histologically. Quantitative analysis of the isotopic uptake by thallium-201 scintigraphy before and after chemotherapy, defined as the alteration ratio, was correlated with the percentage of tumor necrosis. RESULTS: Angiography yielded a sensitivity of 88%, a specificity of 73%, and a predictive accuracy of positive test of 70%, whereas thallium-201 scintigraphy achieved 88%, 100%, and 100%, respectively. Both angiographic and scintigraphic assessment showed a significant correlation with response grade as determined histologically (P < 0.05 and P < 0.0003, respectively). The alteration ratio of thallium-201 scintigraphy showed a strong, highly significant correlation with the percentage of tumor necrosis (P < 0.0001). CONCLUSIONS: A change in the tumor uptake of thallium-201 scintigraphy after preoperative chemotherapy can predict the tumor necrosis in osteosarcoma precisely. Thallium scintigraphy is a noninvasive technique and seems to be more useful than angiography in assessing the response of osteosarcoma to preoperative chemotherapy.

Adolescent↗

Expression of interleukin 15 (IL-15) in human rhabdomyosarcoma, osteosarcoma and Ewing's sarcoma.

Interleukin 15 (IL-15) is a recently discovered cytokine that stimulates lymphocyte proliferation and migration via a trimeric receptor sharing the beta and gamma signal transducing chains with the IL-2 receptor. IL-15 is typically produced by normal cells that do not release IL-2, but little information is currently available on human tumors. To assess whether human musculo-skeletal sarcomas produce IL-15, we analyzed surgical specimens and cell lines obtained from rhabdomyosarcoma, osteosarcoma and Ewing's sarcoma. IL-15 mRNA was present in 9/9 surgical specimens (3 Ewing's sarcomas, 5 osteosarcomas and 1 rhabdomyosarcoma). The analysis of a panel of cell lines (7 derived from Ewing's sarcoma, 12 from osteosarcoma and 5 from rhabdomyosarcoma) showed that all rhabdomyosarcoma and osteosarcoma cell lines expressed IL-15 mRNA at levels ranging from low to high, while Ewing's sarcoma cells contained little or no IL-15 message. ELISA assays showed IL-15 release in a subset of rhabdomyosarcomas and osteosarcomas, but not in Ewing's sarcoma. The highest production of IL-15, in the picogram/ml range, was found in rhabdomyosarcoma cell lines RH30 and RD.

Enzyme-Linked Immunosorbent Assay↗

Modulation of resistance to anti-APO-1-induced apoptosis in osteosarcoma cells by cytokines.

The CD95/APO-1 Fas receptor/ligand system plays a crucial role in growth control by mediating apoptosis in lymphoid and non-lymphoid cells. To investigate the role of CD95-mediated apoptosis in osteosarcoma, we studied 3 human osteosarcoma cell lines (HOS/TE 85, MG 63 and Saos-2) and osteoblasts derived from bone biopsies. In contrast to osteoblast-like cells, all cell lines were resistant to anti-APO-1-induced apoptosis despite constitutive CD95 expression at intermediate levels. Blocking of macromolecular synthesis by cycloheximide or actinomycin D or modulation of CD95 expression by cytokines (TNF-alpha and/or gamma-interferon) restored sensitivity to anti-APO-1-induced cell death. PCR analysis of the CD95 transcripts revealed the production of a truncated splice variant that codes for a soluble form of the CD95 receptor. Synthesis and secretion of soluble CD95 protein into the culture supernatant was demonstrated by Western blot analysis. Treatment with sensitizing cytokines led to up-regulation of full-length CD95 transcripts and the encoded membrane-bound CD95 protein but not the truncated mRNA splice variant and the corresponding soluble receptor, as shown by PCR and Western blot analysis. The biological activity of soluble CD95 secreted by osteosarcoma cells was demonstrated by the ability of osteosarcoma supernatants to protect the sensitive T-cell line Jurkat from anti-APO-1-mediated apoptosis. Our results suggest that the production of soluble CD95 by osteosarcoma cell lines that may block physiological death signals and the production of membrane-bound CD95 are differently regulated by cytokines via modulation of RNA splicing.

Antibodies↗

Postirradiation laryngeal osteosarcoma: case report and literature review.

BACKGROUND: Laryngeal sarcoma is a rare disease entity. In review of the literature, chondrosarcoma is the most common sarcoma, followed by fibrosarcoma. Osteosarcoma is very rare; there are only seven cases reported in the literature. Postirradiation sarcoma is a late complication of radiotherapy. Osteosarcoma is the most common type in this group. The larynx is often involved in the radiation field of treatment for head and neck malignancies. However, postirradiation laryngeal osteosarcoma has not yet been reported. METHODS: We present a 56-year-old man who under went radiotherapy for nasopharyngeal carcinoma 32 years ago and later developed a laryngeal osteosarcoma. RESULTS: The patient underwent total laryngectomy but died 1 year and 9 months later with locally extensive disease. CONCLUSIONS: We report the first case of postirradiation laryngeal osteosarcoma. In addition to surgical treatment, adjunctive therapies should be considered for this group of patients.

Fatal Outcome↗

Specific antigen stimulated lymphocyte proliferation in osteosarcoma.

A lymphocyte proliferation assay (LPA) for cellular immune responses to osteosarcoma antigens is described and applied to an examination of peripheral blood lymphocytes (PBL) taken from osteosarcoma patients. The antigen preparations were derived from 3 M KC1 solubilized osteosarcoma, taken from a limited number of patients. Lymphocytes from most tumor-bearing patients were stimulated to significant proliferation when cultured in normal human serum. Such stimulation was observed whether or not the lymphoid cells were preincubated 24 hours at 37 degrees C prior to addition of antigen. Patients whose lesion had been resected and who were without evidence of disease for 5-70 months had diminished proliferative responses. Lymphocytes from normal subjects, from patients having other types of sarcoma, and patients having carcinomas rarely responded to the soluble osteosarcoma antigens. When responsive PBL taken from tumor-bearing patients were cultured in autologous serum, the proliferative responses were abrogated or blocked. Serial assays made in the course of bearing this tumor under a variety of therapeutic regimens, including an immunotherapy protocol, suggest that the LPA may be useful in monitoring clinical progress of the disease and possibly in other immunotherapy protocols for osteosarcoma.

Antigens, Neoplasm↗

Osteosarcoma, fibrous dysplasia, and a chromosomal abnormality in a 3-year-old child.

Osteosarcoma is a type of malignant bone tumor that is rare among children less than five years old. This report describes a 3-year-old boy with osteosarcoma of the right proximal femur and polyostotic fibrous dysplasia of the right femur and tibia. After hemipelvectomy, histologic examination of the amputated limb disclosed that the osteosarcoma had developed in a focus of fibrous dysplasia. Cytogenetic analysis of the patient's blood lymphocytes revealed a 4q-/7p + translocation in all cells. The patient's mother had an identical translocation but did not have a history of osteosarcoma or evidence of fibrous dysplasia. The chromosomal abnormality and the developmental osseous disorder may have predisposed this patient to developing osteosarcoma at an exceptionally young age.

Child, Preschool↗

DNA analysis in the differential diagnosis of osteosarcoma.

The DNA content of osteosarcomas, and of giant cell tumors, osteoblastomas, aneurysmal bone cysts, and fibrous dysplasias was determined by cytophotometry. Out of 158 tumors, 141 were histologically noncontroversial, whereas 17 posed diagnostic difficulties. In the noncontroversial group all 41 benign tumors had a diploid (normal) DNA content. Ninety-two of 96 high-grade osteosarcomas were hyperploid (increased DNA content). The four analyzed low-grade parosteal osteosarcomas were diploid. Among 17 diagnostically controversial cases, nine were primarily diagnosed and treated as benign. Three of these patients, nevertheless, exhibited a malignant clinical course and two had local recurrence. All five proved to have hyperploid tumors. The four nonrecurrent lesions were diploid. Of eight cases primarily evaluated as malignant, one died and two developed local recurrence. These three patients had hyperploid tumors. Among the five nonrecurrent lesions, two were hyperploid and three diploid. Hence, in the diagnostically controversial group, recurrence or death was consistently related to hyperploidy. The current study shows that the vast majority of high-grade osteosarcomas are hyperploid. Benign bone tumors, which may be mixed up histologically with osteosarcoma, are diploid. Routine DNA analysis of primary bone tumors, as an adjunct to histopathologic assessment, can be employed to obtain diagnostic confirmation. In cases presenting histopathologic difficulties, ploidy determination may provide decisive diagnostic information.

Adolescent↗

DNA analysis in the differential diagnosis of osteosarcoma.

The DNA content of osteosarcomas, and of giant cell tumors, osteoblastomas, aneurysmal bone cysts, and fibrous dysplasias was determined by cytophotometry. Of 158 tumors, 141 were histologically noncontroversial, whereas 17 posed diagnostic difficulties. In the noncontroversial group, all 41 benign tumors had a diploid (normal) DNA content. Ninety-two of 96 high-grade osteosarcomas were hyperploid (increased DNA content). The four analyzed low-grade parosteal osteosarcomas were diploid. Among 17 diagnostically controversial cases, nine were primarily diagnosed and treated as benign. Three of these patients, nevertheless, exhibited a malignant clinical course and two had local recurrence. All five proved to have hyperploid tumors. The four nonrecurrent lesions were diploid. Of eight patients primarily evaluated as malignant, one died and two developed local recurrence. These three patients had hyperploid tumors. Among the five nonrecurrent lesions, two were hyperploid and three diploid. In the diagnostically controversial group, recurrence or death was consistently related to hyperploidy. The present study shows that the vast majority of high-grade osteosarcomas are hyperploid. Benign bone tumors, which may be mixed up histologically with osteosarcoma, are diploid. Routine DNA analysis of primary bone tumors, as an adjunct to histopathologic assessment, can be employed to obtain diagnostic confirmation. In cases presenting histopathologic difficulties, ploidy determination may provide decisive diagnostic information.

Adolescent↗

Osteosarcoma and the role of fine-needle aspiration. A study of 51 cases.

Fifty-one patients were evaluated by fine-needle aspiration (FNA) as part of the diagnosis, staging, and management of osteosarcoma. All patients had histologic confirmation of osteosarcoma. Five patients underwent two aspirations each; thus, the total number of aspirates reviewed was 56. Aspirations were performed by interventional radiologists using fluoroscopic guidance. The cytologic features of osteosarcoma were divided into five groups: (1) pleomorphic (malignant fibrous histiocytoma-like); (2) epithelioid; (3) chondroblastic; (4) small cell; and (5) mixed. Although osteoid-like material was seen, it could not be distinguished readily from dense collagen. The chondroid matrix of chondroblastic osteosarcoma was recognized as a granular film with scattered clear bubbles. Fine-needle aspiration was diagnostic of sarcoma in 45 of 56 aspirates (80.4%). In eight aspirates, the cellularity of the smears was insufficient for diagnosis due to extensively osteoblastic tumors (six), necrotic tumor (one), and undetermined causes (one). In three aspirates, failure was attributed to poor cellular preservation due to unknown factors. The authors conclude that FNA is a useful tool in the multidisciplinary diagnosis and management of osteosarcoma. Aspirates should only be evaluated with full knowledge of the clinical and radiographic findings. The most significant limitation of FNA is the inability to detect osteoid.

Adult↗

Small cell osteosarcoma. A clinicopathologic study of 27 cases.

We report a study of 27 patients with small cell osteosarcoma (SCO), 17 from the M. D. Anderson Cancer Center (MDAH) and ten from the Pediatric Oncology Group (POG). There were 12 male patients and 15 female patients; 19 were white, five were black, and three were Hispanic. They ranged from 6 to 28 years of age with a median of 14 years. Histologically there were three patterns: Ewing's-like, lymphoma-like, and spindle cell. All cases showed osteoid formation and a few had chondroid areas. There was cytoplasmic glycogen in ten cases. Initial treatment for MDAH patients included intraarterial infusion of cisplatin in ten, amputation in four, partial mandibulectomies in two, and biopsy with local radiotherapy and systemic chemotherapy in one. All POG patients had resection or amputation followed by adjuvant chemotherapy. Twelve patients are alive, of whom nine have had significant follow-ups for 25 to 90 months. Fourteen patients are dead of lung, spine, and brain metastases from 1 to 23 months after initial diagnosis. One patient is alive with lung relapse at 4 months. In summary, SCO is a high-grade variant of osteosarcoma, with an incidence of up to 4% of all osteosarcomas, that affects patients of the same age group and has the same anatomic location as conventional osteosarcoma. Currently, SCO appears to have a prognosis that is the same as or slightly worse than that of conventional osteosarcoma. Furthermore, although intraarterial infusion is effective for the primary tumors in the bone, distant metastases are difficult to control.

Adolescent↗

Low-grade intraosseous osteosarcoma.

A study of 80 well-differentiated osteosarcomas, 16 from the Mayo Clinic files and 64 from our consultation files, revealed that males and females were about equally affected, most of the patients were young adults, and skeletal distribution was similar to the distribution seen in conventional osteosarcoma. Radiographs generally showed poor margination, suggestive of malignancy. Histologically, the tumors were composed of spindle cells with only minimal atypia. Some tumors had bone spicules similar to those seen in fibrous dysplasia. An invasive growth pattern was the most helpful feature in differentiating low-grade osteosarcoma from fibrous dysplasia. Initial treatment was highly variable. Local excision was almost always associated with recurrence. Wide excision was almost never followed by recurrence. The recurrent tumor was a high-grade, conventional osteosarcoma in 15% of the patients, and this was associated with a poor prognosis. Wide excision seems to be the treatment of choice for this very rare variant of osteosarcoma.

Adolescent↗

Osteosarcomas of the skull. Clinical remarks on 19 cases.

BACKGROUND: Osteosarcomas are typically long bone tumors and rarely affect the skull, with most articles reporting single cases. As elsewhere in the body, these lesions may be classified as primary or secondary, chiefly post-Paget and post-radiation therapy. METHODS: The authors reviewed the osteosarcomas of the skull diagnosed at the Division of Neurosurgery of "La Sapienza" University of Rome. The patients were placed into two groups, according to the treatment received (prechemotherapeutic era and chemotherapeutic era). In the last five patients, a diagnostic-therapeutic protocol was adopted. RESULTS: The most effective investigations are plain radiographs, computed tomography (CT) with bone windows, and magnetic resonance imaging (MRI), with the latter two allowing assessment of the extraosseous extent of the disease. Chemotherapy has changed the prognosis dramatically, achieving cure in some cases (especially in de novo osteosarcomas). Before the age of chemotherapy, the median survival length was 16 months, but since its introduction, five of nine patients in this study are alive 2 years after diagnosis. The onset of metastases, chiefly to the lung, does not necessarily imply a poor prognosis. The authors propose a schedule for the diagnosis and treatment of new cases of osteosarcoma of the skull. CONCLUSIONS: Plain radiographs, CT targeted on the bone, and MRI are the most important diagnostic tools. Aggressive chemotherapy together with surgery (eventually including local radiation therapy in nontotal macroscopic surgical removal of the lesions) can drastically modify the prognosis of de novo and post-radiation therapy osteosarcomas.

Adolescent↗

Osteosarcoma of the hand. A clinicopathologic study of 12 cases.

BACKGROUND: The incidence of osteosarcoma of the hand is about 0.18% of all osteosarcomas. METHODS: This study describes the clinicopathologic profile of 12 patients (3 Mayo Clinic and 9 consultation) with osteosarcoma of the hand (13 tumors). RESULTS: The patients (six male patients, five female, one unknown) were from 16 to 81 years of age (average, 45). Seven tumors were in phalanges and six in metacarpals. Nine tumors were classified as conventional, one as low-grade intraosseous, one as osteoblastoma-like, one as high-grade surface, and one as periosteal osteosarcoma. Recurrent disease developed in all patients in whom the initial operation resulted in intralesional excision or a marginal margin but not in the five patients in whom the initial operation achieved wide margins. Only one patient died of metastatic disease. CONCLUSIONS: The findings in this review support the conclusion that surgical treatment with a wide margin provides good results in patients with osteosarcoma of the hand.

Adolescent↗

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

BACKGROUND: The authors investigated the incidence and relative risk of secondary malignant neoplasms in long-term survivors of osteosarcoma. METHODS: A comprehensive list of 509 patients with primary osteosarcoma treated at our institution between February 1973 and March 2000 was identified. All study patients received chemotherapy and/or surgery on one of six different protocols (T4, 5, 7, 10, 12, and CCG-7921/POG-9351). Chemotherapy was scheduled for up to 40 weeks with some variations in the actual treatment period and consisted of various combinations of the following agents: high-dose methotrexate, doxorubicin, bleomycin, cyclophosphamide, dactinomycin, vincristine, cisplatin, and ifosfamide. RESULTS: Secondary malignant neoplasms (SMN) occurred in 14 of 509 patients. Only one had pulmonary metastasis at diagnosis and subsequent multiple recurrences that required thoracotomies and further modification of the chemotherapy regimen. The median age at diagnosis for osteosarcoma was 16.6 years (range, 3.1-74.4 years). The median follow-up was 5.2 years (range, 0.1-25.0 years). The time interval from diagnosis of the primary osteosarcoma to the development of SMN was 1.3-13.1 years (median, 5.5; 95% confidence interval [CI], 3.6-9.6). The most common SMN occurred in the central nervous system (n = 4): anaplastic glioma, meningioma, high-grade glioma, and maxillary astrocytoma. There were two cases of acute myeloid leukemia and one case each of myelodysplastic syndrome, non-Hodgkin lymphoma, high-grade pleomorphic sarcoma, leiomyosarcoma, fibrosarcoma, breast carcinoma, and mucoepidermoid carcinoma. The overall 5 and 10-year cumulative incidences of SMNs were 1.4% +/- 1.1% and 3.1% +/- 1.8%. The standardized incidence ratio was 4.6 (95% CI, 2.53-7.78, P = 0.00001) for the cohort and 3.64 (95% CI, 1.82-6.52, P = 0.0007) when patients with a history of retinoblastoma or Rothmund-Thomson syndrome were excluded. CONCLUSIONS: The overall incidence of secondary malignancies in long-term survivors of osteosarcoma was significantly higher than the expected incidence of cancer in the general population. However, the standardized incidence ratios were much lower than those reported for Hodgkin disease and retinoblastoma. Although additional follow-up is warranted, the successes of current treatment regimens consisting of intensive, high-dose chemotherapy in combination with topoisomerase II inhibitors outweigh the risks.

Adolescent↗

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.

Acute Kidney Injury↗

Osteosarcoma of the pelvis in children and young adults: the St. Jude Children's Research Hospital experience.

BACKGROUND: Pelvic osteosarcomas are difficult to resect. The authors reviewed their institution's experience with patients who had such tumors to characterize the patients' clinical findings and to assess the impact of surgical resection on outcome. METHODS: A review was conducted of the records from patients with pelvic osteosarcoma who were treated at the authors' institution between January, 1970 and March, 2004. RESULTS: Among 442 patients with osteosarcoma, 19 patients (4%) had high-grade tumors arising in the pelvic bones, including the ilium in 15 patients, the pubis in 2 patients, and the sacrum in 2 patients. The median patient age at diagnosis was 16.8 years. Four tumors were secondary to radiation therapy. Five patients had metastases in the lung (n = 4 patients) or bone (n = 1 patient) at diagnosis. Ten tumors were chondroblastic. The median greatest tumor dimension for the 13 tumors with known size was 10 cm. Ten patients had unresectable pelvic tumors, and 9 patients underwent hemipelvectomy (2 internal and 7 external); complete resection with negative margins was achieved in 5 patients. Four patients survived, including one patient who survived with disease. Of the three patients who survived disease-free, one patient underwent complete resection, one patient underwent incomplete resection (nonviable tumor at the soft tissue margin) with a good response to chemotherapy, and one patient with a sacral tumor underwent radiotherapy only for local control. Of the 9 patients who underwent resection, 7 experienced disease recurrence (n = 5 patients) or progression (n = 2 patients) at distant sites and died. All patients with metastatic disease at diagnosis died. CONCLUSIONS: Pelvic osteosarcomas often were large and unresectable. A high propensity for metastasis contributed to the poor outcome of patients with pelvic osteosarcoma. New therapeutic approaches are needed.

Adolescent↗

Differentially amplified chromosome 12 sequences in low- and high-grade osteosarcoma.

Most osteosarcomas are highly aggressive malignancies characterized by a complex pattern of chromosome abnormalities. However, a subgroup of low-grade, parosteal tumors exhibits a relatively simple aberration pattern dominated by ring chromosomes carrying amplified material from chromosome 12. To assess whether sequences from this chromosome were differentially amplified in low- and high-grade osteosarcomas, copy numbers of the CCND2, ETV6, KRAS2, and D12S85 regions in 12p and the MDM2 region in 12q were evaluated by interphase or metaphase fluorescence in situ hybridization (FISH) in 24 osteosarcomas. Amplification of MDM2 was detected in all five low-grade and four high-grade osteosarcomas, all of which showed ring chromosomes. An overrepresentation of 12p sequences was found in 1/5 low-grade and in 9/19 high-grade tumors. Multicolor single-copy FISH analysis of metaphase cells from six high-grade tumors showed that extra 12p material either occurred together with MDM2 in ring chromosomes or was scattered over the genome as a result of complex structural rearrangements. Most tumors (8/10) not containing amplification of the assessed chromosome 12 loci exhibited a nondiploid pattern at evaluation with probes for centromeric alpha satellite sequences. These findings indicate that gain of sequences from the short arm of chromosome 12 could be a possible genetic pathway in the development of aggressive osteosarcoma.

Adolescent↗