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Prognostic factors and imaging patterns of recurrent pulmonary nodules after thoracotomy in children with osteosarcoma.

BACKGROUND: In children with osteosarcoma who have undergone thoracotomy, it often is difficult to distinguish metastatic from benign recurrent pulmonary nodules. The authors of this study sought to identify any computed tomography (CT) imaging pattern of recurrent pulmonary metastases in this patient population. The authors also sought to identify associated prognostic factors. METHODS: CT scans obtained after thoracotomy were available for 35 patients with osteosarcoma who had undergone resection of presumed pulmonary metastases at St. Jude Children's Research Hospital (Memphis, TN). CT scans obtained before the initial thoracotomy were available for 33 of the 35. The authors recorded location, histologic diagnosis, and time of development of the original pulmonary nodules, time of recurrence of pulmonary disease; the location of recurrent nodules, and the presence of calcification, adenopathy, or progressive pleural disease, as well as patient demographic data, survival data, and location of the primary tumor site. RESULTS: Pulmonary nodules recurred in 32 of the 35 patients after thoracotomy. Nineteen of these patients underwent resection of the recurrent lesions and 1 who died underwent an autopsy; 18 of the 20 patients had metastatic disease. The only CT finding consistently associated with recurrent metastatic disease was progressive pleural thickening, which predicted a poor outcome. The occurrence of a solitary pulmonary nodule in the lung contralateral to the previous surgery was associated almost always with a benign process. CONCLUSIONS: CT imaging cannot distinguish reliably between benign and metastatic recurrent pulmonary disease after thoracotomy in patients with osteosarcoma. Recurrent pulmonary disease in this set of patients is likely to be metastatic, and aggressive surgical intervention is probably warranted. In this study, patients who had progressive pleural disease after thoracotomy consistently experienced pulmonary metastatic recurrence and had a poor prognosis.

Adolescent↗

Loss of p16(INK4a) expression correlates with decreased survival in pediatric osteosarcomas.

Abnormalities of the G1 cell-cycle checkpoint are commonly reported in cancers at various anatomic sites. pRB, p16(INK4a) and cyclin D1 are critical G1-checkpoint proteins responsible for maintaining the balance of cellular proliferation. We examined a series of 38 pediatric osteosarcomas for abnormal expression of pRB, p16(INK4a) and cyclin D1 by immunohistochemical analysis of archival biopsy specimens. Overall, 17/38 (45%) osteosarcomas showed evidence of G1-checkpoint abrogation, including 11/38 (29%) with loss of pRB expression and 6/38 (16%) with loss of p16(INK4a) expression. Cyclin D1 over-expression was not detected. There was an inverse correlation between loss of pRB and p16(INK4a) expression (p = 0.07). pRB and p16(INK4a) abnormalities were independent of site of disease, presence of metastasis at diagnosis and percentage of tumor necrosis in the resection specimen. Clinical follow-up was available on all patients (median 31.6 months, range 5.9-116 months). Absence of p16(INK4a) expression significantly correlated with decreased survival in univariate analysis (p = 0.03), while loss of pRB expression did not affect survival. Immunohistochemical analysis of p16(INK4a) expression in pediatric osteosarcomas may be a useful adjunctive marker of prognosis.

Adolescent↗

Can cure in patients with osteosarcoma be achieved exclusively with chemotherapy and abrogation of surgery?

BACKGROUND: Contemporary therapy for osteosarcoma is comprised of initial treatment with chemotherapy and surgical extirpation of the primary tumor in the affected bone. In view of the major advances forged by chemotherapy in the treatment of the primary tumor, an attempt was made to destroy the tumor exclusively with this therapeutic modality and abrogate surgery. METHODS: Thirty-one consecutive patients were treated. All had localized disease (absence of metastases) at the time of diagnosis. Initial treatment with chemotherapy was comprised of high-dose methotrexate and leucovorin rescue (MTX-LF) in 3 patients and intraarterial cisplatin in 28 patients. Clinical, radiologic, angiographic, radionuclide, and histologic investigations were utilized to assess the efficacy of treatment. After a response at 3 months, entry into the study was permitted and treatment was maintained for a total of 18-21 months with a combination of agents comprised of MTX-LF, intraarterial cisplatin, and doxorubicin. Patients were monitored closely for disease recurrence with the investigations outlined earlier. Two informed consents were required: one at the time of diagnosis and another at 3 months after the initial response had been attained. RESULTS: Only 3 of 31 patients were cured with the administration of chemotherapy alone. Local recurrence and pulmonary metastases were not reported to develop in these 3 patients during a follow-up period of 204+ to 225+ months. Four other patients also possibly were cured with chemotherapy alone. At their request, several months after the cessation of chemotherapy, they underwent surgical extirpation of the tumor. No evidence of viable tumor was found. These patients remained free of disease for 192+ to 216+ months. Thus, only seven patients did not develop local recurrence and/or pulmonary metastases. Among the remaining 24 patients, 9 developed local recurrences without pulmonary metastases 14-74 months (median, 30 months) after the initial response. Eight of the nine patients were rendered tumor free by extirpation of the local recurrence. Two of these eight patients subsequently died, one of the acquired immunodeficiency syndrome (AIDS) and the other of varicella septicemia. The ninth patient refused amputation and died of metabolic complications. Three other patients developed local recurrences 20-69 months and pulmonary metastases 10-98 months after achievement of the initial response. These patients were rendered tumor free by extirpation of the local recurrence and metastasectomy. One of these patients also later died of AIDS. In the remaining 12 patients, local recurrences developed 5-29 months (median, 14 months) after the initial response was achieved. The patients also developed pulmonary metastases 11-60 months after the initial response. In eight patients the local recurrences were extirpated and metastasectomy was performed; however, these patients later died of recurrent pulmonary metastases. The remaining four patients refused to undergo extirpation of the local recurrence. The pulmonary metastases were not resected. They failed to respond to alternate therapy. Thus, the tumor-free survival rate was 23% (7 of 31 patients): 3 patients who were treated with chemotherapy only and 4 patients who were treated with chemotherapy plus surgery. The overall survival rate (patients who remained free of disease and those who underwent resection for local recurrence and metastasectomy) was 48% (15 of 31 patients). Prior to the deaths from AIDS and varicella septicemia, the overall survival was 58% (18 of 31 patients). CONCLUSIONS: Utilizing the regimen employed in the current study, only 3 of 31 patients with osteosarcoma (10%) were cured exclusively with chemotherapy. Four additional patients who underwent extirpation of the primary tumor without disease recurrence and in whom no viable tumor was found in the resected specimens possibly could increase the number of patients who potentially were cured with chemotherapy to 7 (23%). With an overall expected cure rate of 50-65% with "conventional" sin whom no viable tumor was found in the resected specimens possibly could increase the number of patients who potentially were cured with chemotherapy to 7 (23%). With an overall expected cure rate of 50-65% with "conventional" strategies, the results of the current study do not justify the adoption of current forms of chemotherapy as exclusive treatments for osteosarcoma.

Adolescent↗

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.

Adolescent↗

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

BACKGROUND: Recurrent osteosarcoma is a drug-resistant disease with a dismal prognosis. The objective of this Phase II study was to evaluate the activity of ecteinascidin 743 (ET-743) as a salvage therapy in these patients. METHODS: Patients with recurrent osteosarcoma who had received standard chemotherapeutic agents were eligible. ET-743 was administered at a dose of 1500 microg/m(2) as a 24-hour infusion every 3 weeks. Pharmacokinetic studies were performed during the first cycle. RESULTS: Twenty-five patients were enrolled, 23 of whom were assessable for response (median age of 18 years; range, 12-67 years). The median number of previous chemotherapeutic agents was five (range, three to eight previous agents). Sixty-one cycles were administered (median number of cycles per patient was 2; range, 1-9 cycles per patient). Three patients (12%) achieved minor responses (49% 36% and 25%, respectively). Fifteen patients (60%) developed a transient elevation of hepatic transaminases (Grade 3 or 4 [according to the National Cancer Institute Common Toxicity Criteria]), which was not cumulative. Grade 3 or 4 neutropenia and thrombocytopenia were observed in 12 patients (48%) and 6 patients (24%), respectively. The mean area under the curve (AUC) in 4 patients experiencing Grade 4 toxicity (76.4 +/- 29.3 ng x hr/mL) was significantly greater (P = 0.034) than that in those for whom the most severe toxicity was Grade 3 (39.5 +/- 17.2 ng x hr/mL [n = 12]) or Grade 1-2 (52.6 +/- 15.6 ng x hr/mL [n = 5]). There were no other significant correlations found between pharmacokinetic variables and patient characteristics, toxicity, or therapeutic response. CONCLUSIONS: ET-743 was found to be well tolerated in heavily pretreated osteosarcoma patients but had limited antitumor activity as a single agent. The combination of ET-743 with cisplatin or doxorubicin should be considered.

Adolescent↗

Single and multiple metachronous osteosarcoma tumors after therapy.

BACKGROUND: The objective of the current study was to determine the incidence, clinical and pathologic characteristics, and outcome of patients with conventional osteosarcoma who developed metachronous tumors after treatment for the primary tumor and prevention of pulmonary metastases. METHODS: The medical records of 270 pediatric patients (younger than age 18 years) were reviewed. The prevention and absence of pulmonary metastases was confirmed by chest radiographs and computerized scans of the lungs. Radionuclide bone scans were used to confirm the absence of skeletal metastases. RESULTS: Eleven patients with metachronous tumors were identified. Index primary tumors involved the femur (n = 8), the tibia (n = 2), and the radius (n = 1). Single metachronous tumors developed in the femur (n = 6), in the humerus (n = 1), and multifocal in multiple bones (n = 4). Two patients later developed second metachronous tumors. The interval between identification of the primary tumor to development of the single metachronous tumors varied from 11 months to 78 months and from 12 months to 42 months for synchronous multifocal tumors. Metachronous tumors were treated with single-agent cisplatin or ifosfamide. Only 1 patient experienced > 90% tumor necrosis. Pulmonary metastases were not detected in 10 of 11 patients at the time metachronous tumors were discovered. In the 11th patient, synchronous pulmonary metastasis with the metachronous tumor was noted. Three patients had a prior history of bilateral retinoblastoma. The Li-Fraumeni syndrome may have been present in another patient. Six patients died. Five patients have survived for 20+ to 50+ months after the appearance, treatment, and resection of metachronous tumors. CONCLUSIONS: With improvement in the cure rate, metachronous osteosarcoma should be recognized as an important sequela in long-term survivors. The etiology of this disease is unknown. Speculation rests on a skeletal multicentric origin, which includes an inherited predisposition to develop osteosarcoma in retinoblastoma and in the Li-Fraumeni syndrome. Meticulous follow-up is required to permit early detection and successful therapeutic intervention.

Adolescent↗

Evaluation of P-glycoprotein, HER-2/ErbB-2, p53, and Bcl-2 in primary tumor and metachronous lung metastases in patients with high-grade osteosarcoma.

BACKGROUND: Investigation of the relation between primary tumor and metastatic disease is necessary for the identification of predictive factors for postrecurrence survival (PRS) in patients with recurrent osteosarcoma. METHODS: Cellular levels of P-glycoprotein, ErbB-2, p53, and Bcl-2 expression were evaluated in primary tumor biopsy and metachronous pulmonary metastasis specimens from 19 patients with high-grade osteosarcoma. Results were analyzed for differences between primary tumor and pulmonary metastases and for correlations between expression patterns and survival. RESULTS: Positive staining in lung metastases was noted in 68%, 53%, 32%, and 84% of patients for P-glycoprotein, ErbB-2, p53, and Bcl-2, respectively. These percentages were higher than those observed in primary tumor specimens for all genetic markers evaluated, with a significant difference in the percentage of patients with positive staining for P-glycoprotein (68% vs. 32%; P = 0.05) and a near-significant difference in the percentage of patients with positive staining for Bcl-2 (84% vs. 53%; P = 0.08). Patients with ErbB-2 expression in the primary tumor were more likely to have multiple metastases and shorter recurrence-free intervals compared with patients in whom ErbB-2 expression was not observed, whereas differences in P-glycoprotein, p53, and Bcl-2 expression were not related to differences in metastatic pattern. PRS was influenced by p53 expression levels in pulmonary metastases, with patients who had negative staining for p53 having a significantly better PRS rate relative to patients with positive staining for p53 (3-year PRS rate: p53-negative, 64%; p53-positive, 17%; P = 0.008). CONCLUSIONS: In the current study of patients with high-grade osteosarcoma, most patients exhibited increased cellular expression of P-glycoprotein, ErbB-2, and Bcl-2 in recurrent pulmonary metastases compared with primary tumor. Further studies aimed at investigating the relation between altered p53 expression in lung metastases and postrecurrence survival are recommended.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

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.

Adolescent↗

Metastatic osteosarcoma at diagnosis: prognostic factors and long-term outcome--the French pediatric experience.

BACKGROUND: The objective of this report was to estimate long-term outcome and prognostic factors in children and adolescents who presented with metastatic osteosarcoma at diagnosis. Patients were treated in six French pediatric oncology centers with surgery and multiagent chemotherapy, mainly with high-dose methotrexate. Their medical records were reviewed retrospectively. METHODS: The medical records of patients who were treated for metastatic osteosarcoma from 1987 to 2000 were reviewed. Patients were treated with the chemotherapy regimens recommended for nonmetastatic disease in children (the French Society of Pediatric Oncology OS 87 and OS 94 protocols) or, in a few patients, with other chemotherapy regimens. Surgical excision of the primary tumor and, when possible, of all metastatic sites was performed based on a personalized assessment of each patient's situation. RESULTS: Seventy-eight patients age < 20 years were treated. Forty-six patients (59%) had only 1 metastatic site (35 to the lungs and 11 to bone). Twenty-eight patients (36%) achieved a complete remission after combination chemotherapy and surgery. The event-free survival and overall survival rates at 5 years were 14% and 19%, respectively. To date, 14 patients (18%) have remained alive with a median follow-up of 112 months. Pretreatment features associated with a shorter event-free survival in the multivariate analysis were metastasis to at least two organs and high alkaline phosphatase level. Patients with at least 1 of these poor prognostic factors had a 2.6% event-free survival rate at 5 years despite treatment. CONCLUSIONS: The survival of patients with metastatic osteosarcoma were treated with conventional chemotherapy and surgery remained very poor. Patients should be classified into different prognostic groups and treated accordingly. New therapeutic approaches are warranted to improve the prognosis for patients with the most severe disease.

Adolescent↗

Resection of recurrent pulmonary metastases in patients with osteosarcoma.

BACKGROUND: Surgical resection of lung metastases is widely accepted in osteosarcoma patients. Few data exist on treatment of recurrent pulmonary metastases. The authors of the current study retrospectively analyzed patients with osteosarcoma who received surgery for recurrent lung metastases. METHODS: From 1980 to 2001, 127 metastasectomies were performed on 94 patients. Criteria of eligibility were no metastases beyond the lung, no local recurrence, possibility of achieving complete resection of metastases without causing respiratory insufficiency, acceptable operative risk. Data were statistically elaborated with survival analysis according to Kaplan-Meier method of univariate analysis, life tables and Gehan statistic model, and multivariate analysis using Cox regression test. Results were considered in terms of time from first (DFI1) and second (DFI2) metastasectomy. RESULTS: Of 94 patients operated upon twice, 59 (62.7%) died. Thirty-five (37.3%) are alive; 31 (32.9%) of these are continuously disease-free. The 3- and 5-year event-free actuarial survival curve from first metastasectomy was 45%, and 38%, respectively, whereas from the second metastasectomy, it was 33% and 32%, respectively. According to a Cox regression model, DFI1 has a risk of death of 0.974 times and DFI2 of 0.972 times for every additional month of survival. In multivariate analysis, Cox regression test showed the best predictive model of local recurrence and number of metastases (P = 0.0014). CONCLUSIONS: The authors concluded that patients persistently free of the primary osteosarcoma who developed recurrent resectable metastatic disease of the lung should be considered for reoperation a second, third, or fourth time, as these patients had similar DFI curves after five-years.

Adolescent↗

Prognostic factors for osteosarcoma of the extremity treated with neoadjuvant chemotherapy: 15-year experience in 789 patients treated at a single institution.

BACKGROUND: The evaluation variables influencing systemic and local recurrence and final outcome are extremely important in defining risk-adapted treatments for patients with nonmetastatic osteosarcoma of the extremity. METHODS: A homogeneous group of 789 patients treated at a single institution between March 1983 and March 1999 with different protocols of neoadjuvant chemotherapy, with a minimum followup of 5 years, were retrospectively evaluated in relation to gender, age, serum levels of alkaline phosphatase, tumor site and size of the pathologic fracture, type of surgery, protocol of chemotherapy, surgical margins, and histologic response to preoperative treatment. RESULTS: The 5-year event-free survival (EFS) and overall survival rates were 60.1% and 67.5%, respectively. Upon univariate analysis, EFS was significantly related to the age of patients, serum value of alkaline phosphatase, tumor volume, histologic subtype, type of surgery, surgical margins, histologic response to preoperative treatment, and chemotherapy protocol. Local recurrences (4.8%) were significantly correlated with surgical margins. The 5-year post-recurrence EFS survival was 17% and was significantly lower for patients who had a local recurrence and metastases than for those with metastases only. Patients who had a recurrence only in the lung had a post-recurrence survival rate significantly better than others, correlated with the number of metastatic nodules and the length of the disease-free interval. CONCLUSIONS: Upon multivariate analysis, age < or = 14 years, high serum levels of alkaline phosphatase, tumor volume > 200 mL, a two-drug regimen chemotherapy, inadequate surgical margins, and poor histologic response to treatment maintained independent prognostic values on the outcome of nonmetastatic osteosarcoma of the extremities. These factors must be considered when deciding risk-adapted treatments for osteosarcoma patients.

Adolescent↗

Influence of local recurrence on survival in patients with extremity osteosarcoma treated with neoadjuvant chemotherapy: the experience of a single institution with 44 patients.

BACKGROUND: Risk factors for local recurrence (LR) after osteosarcoma, such as surgical margins and histologic response to preoperative treatment, have been well documented, whereas the outcome for patients who locally recur has not been well established yet. METHODS: Retrospective analysis of the management and outcome of 44 patients who developed LR after treatment of osteosarcoma of the extremities with neoadjuvant chemotherapy was performed in a single institution between 1983 and 1999. RESULTS: In 24 patients (54.5%), LR was the first sign of recurrence; in 8 patients (18.2%) LR followed systemic recurrence and in 12 patients (27.3%), the 2 events, local and systemic recurrence, were concurrent. Of the 44 patients, 26 with local recurrences were free of disease, but only 5 were long-term event-free survivors, and 39 patients developed further recurrences: 37 died of the tumor and 2 were alive with uncontrolled disease at the time of last follow-up. The 5-year disease-free survival rate after the last recurrence was 15.9%; it was 25.9% for patients who achieved remission and 0% for the others. The only prognostic factor identified for post-LR disease-free survival was the presence of systemic recurrence at the time of diagnosis of LR or before (5-year postrecurrence event-free survival rate of 29.1% for patients without metastases at the time of local recurrence vs. 0% for those with metastases; P = .02). CONCLUSIONS: These results confirm that patients with osteosarcoma of the extremities who develop LR are at a very significantly high risk of developing metastatic disease and dying of the tumor.

Adolescent↗

Treatment algorithm for locally recurrent osteosarcoma based on local disease-free interval and the presence of lung metastasis.

BACKGROUND: Local recurrence in osteosarcoma is clinically distinct from metastasis, although associated with a similar reduction in survival. The prognostic factors in locally recurrent osteosarcoma were investigated and these factors were translated into a management strategy. METHODS: In all, 407 consecutive patients with skeletal osteosarcoma between 1977 and 2002 were analyzed. Twenty-three patients with resectable local recurrence were analyzed. Clinical and tumor-related factors were assessed for significance in relation to survival and a management strategy was formulated based on factors found to be independently significant for survival. RESULTS: Seventeen of the 23 patients underwent primary resections and initial treatment, yielding an overall local recurrence rate of 4.2% for resectable cancer. Median time to local recurrence was 13 months (95% confidence interval, 9-16 months). The 5-year and 10-year survival rates in the recurrent cases were 29% and 10%, respectively. All patients received chemotherapy both for their primary and recurrent disease. Increased risk of local recurrence (P < .0001) was strongly correlated with positive margins of resection. The rate of local recurrence was not related to chemotherapy-associated necrosis in the primary tumor. Nevertheless, neoadjuvant therapy halved the risk of local recurrence (odds ratio, 1.92; P = .3, power 10%). The strongest correlate with poor survival was local recurrence within the first year after primary resection (P = .001), followed by metastasis at the time of first local recurrence (P = .04) and failure to achieve clinical remission after disease recurrence (P = .04). Chemotherapy-associated necrosis and margins of resection of the primary tumor were not significant prognostic variables for survival. Survival differed significantly among patients defined by local disease-free interval and lung metastasis (P = .0001). They required an individualized approach as captured in the management algorithm. CONCLUSION: There is a residual risk of local recurrence in patients despite favorable chemotherapy-associated necrosis and negative margins of resection. A treatment strategy emphasizing clinical remission at all identifiable sites offers the highest likelihood of survival in this patient population.

Adolescent↗

"Skip" metastases in osteosarcoma.

Careful study of 40 cases of osteosarcoma without evidence of multifocal disease, pulmonary metastasis, or history of exposure to predisposing factors has given histologic evidence of microscopic foci of osteosarcoma separate from the primary focus of osteogenic sarcoma. These "skip" lesions are to all pathologic examination completely separate from the primary focus of osteogenic sarcoma. They are more often found proximal to the primary, both intraosseously and transarticularly. Histologically, these "skips" represent areas of osteosarcoma which in many cases are a less-differenitated form of the tumor. The natural history of such tumors with "skips" following ablative surgery is an increased incidence of local recurrence and subsequent pulmonary metastases.

Adolescent↗

Mutations of the CHK2 gene are found in some osteosarcomas, but are rare in breast, lung, and ovarian tumors.

Checkpoint genes, activated in response to DNA damage and other stresses, are frequently targeted for alteration in cancer. Checkpoint kinase 2 (CHK2, CDS1, RAD53) is activated by ataxia telangiectasia mutated (ATM) in response to gamma irradiation. Activated CHK2 stabilizes TP53, and acts on other cell cycle and stress regulators. These findings place CHK2 in the middle of a pathway frequently targeted in cancer. Because of this, and the observation that CHK2 mutations are inherited in some Li-Fraumeni cancer syndrome families, we decided to examine the role of CHK2 mutations in sporadic cancers. Exploiting the genomic sequence of chromosome 22, we looked for mutations in the exons and intron junctions of the CHK2 gene in DNA samples from 170 patients (57 osteosarcomas, 25 other sarcomas, 35 nonsmall-cell lung, 20 ovarian, and 33 breast cancers). Missense mutations affecting the forkhead and kinase domains were detected in four osteosarcomas and in one ovarian and one lung cancer. These findings of CHK2 gene mutations are consistent with osteosarcoma being a defining tumor of Li-Fraumeni syndrome. The occurrence of CHK2 mutations in sporadic cancers emphasizes the importance of the stress pathway which includes TP53.

Amino Acid Substitution↗

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

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

Actins↗

Epithelioid osteosarcoma presenting as a rapidly expanding maxillary mass.

BACKGROUND: Osteosarcomas of the jaws account for less than 10% of reported neoplasms of this type. Patients with osteosarcoma in this region tend to be in the late-third to mid-fourth decades of life. The osteoblastic, chondroblastic, and fibroblastic variants constitute the majority of lesions. METHODS: A mass was observed in the maxilla of a 50-year-old male who presented for a complete odontectomy. Over the ensuing weeks, the mass substantially increased in size, despite multimodality treatment efforts. RESULTS: Radiographic findings revealed a mixed density mass of the left maxilla. Histologic, immunohistochemical, and electron microscopy examination of the tumor showed a malignant mesenchymal neoplasm consisting of sheets of epithelioid and spindle cells exhibiting focal osteoid formation. CONCLUSIONS: We report a rare and aggressive case of epithelioid osteosarcoma arising in the maxillofacial complex.

Epithelioid Cells↗

Malignant bone tumours induced by a local injection of colloidal radioactive 144Cerium in rats as a model for human osteosarcomas.

Lung metastases were observed in 80% to 85% of rats bearing advanced malignant bone tumours (osteogenic osteosarcomas and angiosarcomas). These tumours were induced in 2-month-old Sprague-Dawley rats by inoculation of a colloidal suspension of radioactive cerium (144Ce) into the hind leg, in close contact to the bones of the knee joint. Twenty-eight rats were killed or died spontaneously shortly after detection of palpable tumours at the site of injection: the incidence of lung metastases was 73.3% and 53.8%, respectively, for osteogenic sarcomas and angiosarcomas, showing that most lung metastases are present at the time of diagnosis of the primary tumour. Tumour-cell kinetic parameters were studied in 49 rats bearing tumours following intraperitoneal injection of [3H]thymidine. The labelling index (LI) of the primary tumours was significantly lower in advanced tumours (7.2% for osteosarcomas and 10.1% for angiosarcomas) than than in tumors examined at the time of detection (12.2% and 13.5%, respectively). Mitotic indices (MI) of all tumours were less than 1%. From the curve of the percentage of labelled mitoses (PLM) at different times after [3H]thymidine injection, Ts (6.5 h) and TG2 (1.75 h) were determined. TC and TG1 were also evaluated (18 h and 9.25 h, respectively). These results show that malignant bone tumours induced in rats with 144Ce may be a good model for human osteosarcomas and may be useful in studying the numerous problems in the therapy of malignant bone tumours in man.

Animals↗