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Biomedical subjects

C B Pratt

Publications and source records attributed to C B Pratt.

At least 19 recordsLinked to original sources
PubMed1996

Alveolar soft part sarcoma in children and adolescents: clinical features and outcome of 11 patients.

The clinical features and response to therapy of pediatric alveolar soft part sarcoma, a rare soft tissue sarcoma of uncertain histogenesis, have not been previously described in detail in the literature. We retrospectively reviewed the clinical characteristics of all patients with alveolar soft part sarcoma who were seen at our institution over a 32-year period. We found 11 patients with the diagnosis of alveolar soft part sarcoma. Their ages ranged from 2.8-16 years (median 9.8). Staging was determined using the Intergroup Rhabdomyosarcoma Study clinical grouping system and the UICC TNM system. Accordingly, there were six patients with grossly resected tumors (clinical groups I and II) and five with unresected or metastatic disease (clinical groups III and IV). Children with resected disease were more likely to have smaller noninvasive tumors. The main feature predictive of survival was tumor resectability, since chemotherapy in various combinations failed to produce significant tumor responses. Nine patients are disease-free with a median follow-up of 11.9 years. Surgical resection remains the mainstay of therapy for pediatric alveolar soft part sarcoma. Since active chemotherapy agents have not been identified, patients with unresected or metastatic disease may benefit from experimental agents. The survival rate of this cohort is superior to that seen in adults.

Adolescent↗
PubMed1996

Outcome in 43 children presenting with metastatic Ewing sarcoma: the St. Jude Children's Research Hospital experience, 1962 to 1992.

The purpose of this work was to review the St. Jude Children's Research Hospital experience of patients presenting with metastatic Ewing sarcoma over a 30-year period. Forty-three of 212 cases of Ewing sarcoma presented with metastases at diagnosis. These patients were analyzed to determine whether primary tumor site or size, metastatic site(s), or advances in therapy have had a positive impact on survival. The overall survival for our 43 patients was 35% (95% confidence intervals, 20% to 50%). Comparing patients treated prior to 1979 with those treated after 1979, the overall survival was significantly different (P = 0.0002). Comparing overall survival between pelvic and non-pelvic primaries (P = 0.24), among metastatic sites (P = 0.83), and between tumors measuring > 8 cm in diameter to tumors measuring < 8 cm in diameter (P = 0.12), no significant differences were observed. Approximately one-third of patients presenting with metastatic Ewing sarcoma may achieve long-term survival. Children with metastatic Ewing sarcoma may benefit from clinical trials which intensify the doses of doxorubicin, and the highly effective combination of ifosfamide/etoposide.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Role of irradiation in management of synovial sarcoma: St. Jude Children's Research Hospital experience.

The role of irradiation in the management of synovial sarcoma (SS) in pediatric patients is evaluated. The review covers all children seen at St. Jude Children's Research Hospital between May 1969 and December 1992 with the diagnosis of soft tissue sarcoma, of the 37 patients with the subtype SS, 16 received irradiation for the management of primary site disease. There were four IRS Group I, six Group II, four Group III, and two Group IV patients receiving irradiation. Tumor grade included seven Grade II, and nine Grade III lesions. TMN staging identified eight T1 and eight T2 lesions. Follow-up has ranged from 14 to 117 months (med = 33 months). All IRS Group I patients had documented local control. Five of six IRS Group II and 4/4 Group III patients have had documented local control at last follow-up. IRS Group IV patients had either local control tumor stabilization (n=1) or evidence of tumor regression (n=1) at autopsy. Complications following irradiation include wound dehiscence (n=1), surgery to revise a painful scar (n=1) extremity length discrepancy (n=2), and femoral head avascular necrosis (n=1). At last follow-up, 10 of 14 patients receiving curative intent irradiation remain alive. This review indicates questionable benefit to the addition of irradiation for patients with adequate surgical resection and having "good" tumor characteristics (Grade I, II; IRS Group I, TMN T1A,T1B. For lesions that have had incomplete resection or partial response to chemotherapy, there is evidence that irradiation may provide durable local control. The role of irradiation in those patients with IRS Group IV disease is at present confined to palliative roles until the time when more effective chemotherapy will mandate the decision to treat primary disease for curative measures.

Adolescent↗
PubMed1996

Treatment outcome and dose-response relationship in infants younger than 1 year treated for retinoblastoma with primary irradiation.

Thirty-three infants ( < 1 year at diagnosis) were treated for retinoblastoma with primary irradiation at St. Jude Children's Research Hospital (SJCRH) between 1963 and June 1992. Staging of the 44 treated eyes was as follows: Reese-Ellsworth (R-E) Groups I (n = 20), Group II (n = 9), Group III (n = 6), Group IV (n = 2), Group V (n = 7). Irradiation was delivered using either a single anterior field (31 eyes) or lens-sparing techniques (13 eyes). Total doses ranged from 21-45 Gy (median = 36 Gy) in fractions of 150-180 cGy (n = 34) or > 180 cGy (n = 10). One child died of metastatic disease at 42 months. Three patients have developed second malignant neoplasms; two have succumbed at 88 and 125 months post-RB diagnosis; the remaining patients are alive at 6-259 months postdiagnosis (median follow-up = 127 months). Local control with irradiation alone and supplemented cryotherapy given within 2 months (n = 2) was maintained in 29 eyes, with no statistical difference seen for total doses < or = 36 Gy (21/8 eyes) vs. > 36 Gy (8/16). Of 15 eyes that required salvage therapy, tumor control has been maintained in 13. Enucleation was required for four patients, two with recurrent retinoblastoma and one with a phthisical eye. Cataract formation was documented in 23 eyes (87.5%) treated with lens-sparing techniques developed cataract. At last follow-up, 23 of 30 patients tested (77%) had visual acuity of 20/100 or better. This experience confirms early observations in that doses > or = 36 Gy do not appear to improve local control with irradiation alone in infants ( < 365 days) with retinoblastoma.

Cryotherapy↗
PubMed1996

Response of pediatric malignant solid tumors following ifosfamide or ifosfamide/carboplatin/etoposide: a single hospital experience.

One hundred thirty-eight pediatric patients have received treatment for malignant solid tumors with ifosfamide with mesna, and 71 have received a combination with ifosfamide/carboplatin/etoposide (ICE). Responses were obtained in many types of pediatric tumors, yet comparison of responses was not possible because of inadequate numbers of tumors of differing histiotypes. Comparison of results between patients with all tumors treated with ifosfamide or ICE indicated that there was a higher response rate for patients treated with ICE, with an estimated odds ratio of 2.74 (95% C.I. 1.45-5.179). Excluding patients without prior chemotherapy and radiotherapy, the odds ratio for 2.801 (95% C.I. 1.45-5.4) suggests a similar result. There remain no guarantees that the more costly treatment with ICE, which requires cytokine support, will offer therapeutic benefits against resistant solid tumors.

Antineoplastic Agents, Alkylating↗
PubMed1996

Topoisomerase I interactive drugs in children with cancer.

Topotecan, irinotecan, and 9-aminocamptothecin (9-AC) are analogs of the plant alkaloid 20(S)-camptothecin (CMT), the prototypical DNA topoisomerase I interactive agent. These agents interact with the topoisomerase I-DNA complex and prevent resealing topoisomerase I-mediated DNA single-strand breaks. This eventual leads to double-strand DNA breaks and apoptosis or cell death. Topotecan, irinotecan, and 9-AC have shown significant activity in mice bearing pediatric solid tumor xenografts; the greatest antitumor responses were found with protracted continuous schedules. Preclinical data also suggest that maintenance of an exposure-duration threshold (EDT) may be required to achieve optimal cytotoxicity. Pediatric Phase I trials have evaluated the toxicity and safety to camptothecin analogs in children with relapsed solid tumors and relapsed acute leukemia. The primary dose-limiting toxicity (DLT) for the CMT analogs in children has been myelosuppression, except for mucositis observed with the 120-hr continuous topotecan infusion schedule. Pharmacodynamic relationships with these analogs have been reported between systemic exposure, and myelosuppression and mucositis. Although not a primary objective of the early Phase I studies, antitumor responses have been reported. In this review, the pharmacokinetic and pharmacodynamics of the CMT analogs studied in children are summarized, and future studies of these agents are discussed.

Animals↗
PubMed1996

Malignant melanoma in children: imaging spectrum.

OBJECTIVE: The objective of this study was to investigate the role of diagnostic imaging in detecting unsuspected metastatic disease in children with malignant melanoma. This has not been well studied previously. MATERIALS AND METHODS: We correlated imaging findings of 33 children diagnosed with melanoma with the level of invasion and clinical stage of disease. RESULTS: Clinically undetectable metastases were identified in eight patients (25 %), four of whom had multiple metastases. All eight patients had deep lesions (Clark's level IV or V) or unknown primary sites of disease. CONCLUSION: Children with thick melanomas and those with unknown site of primary tumors are at increased risk of having clinically unsuspected metastases and should undergo CT of the chest, abdomen, and local-regional nodal basins at diagnosis to determine disease extent.

Abdominal Neoplasms↗
PubMed1996

Phase I trial and pharmacokinetic (PK) and pharmacodynamics (PD) study of topotecan using a five-day course in children with refractory solid tumors: a pediatric oncology group study.

PURPOSE: A phase I trial was conducted in children with refractory solid tumors to determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics, and pharmacodynamics for topotecan administered by a 30-min infusion for 5 consecutive days. PATIENTS AND METHODS: Forty children with a variety of recurrent solid tumors, including nine patients with neuroblastoma and 10 with brain tumors, were given topotecan as a 30-min infusion for 5 consecutive days, beginning with a dose of 1.4 mg/m2/day. The dose was escalated in 20% increments after establishing that DLT was not present at the prior dose. Drug toxicity was graded using standard criteria. Dose-limiting toxicity was defined as grade 3 or 4 nonhematopoietic toxicity or grade 4 hematopoietic toxicity lasting > 7 days. Pharmacokinetic studies were performed during the first infusion course. RESULTS: The DLT was hematopoietic and involved both platelets and neutrophils. Grade 4 hematopoietic toxicity of brief duration was seen at all dose levels. Over half of the patients received red blood cell transfusion support, and 19/40 received platelet transfusions. Hospital admissions for fever and neutropenia or for documented infections occurred in 32 of 169 courses of therapy. Gastrointestinal symptoms with nausea and vomiting or diarrhea were mild to moderate in 12 of the 40 patients. Antitumor responses were seen in three patients with neuroblastoma. An additional four patients (one with neuroblastoma, two with anaplastic astrocytomas, one with Ewing) had stable disease with continued therapy for > 6 months. Using a limited sampling model, pharmacokinetic studies were performed in 36 of the 40 patients. Topotecan lactone and total clearance were similar to those reported in other pediatric populations receiving topotecan by continuous infusion. A pharmacodynamic relation between systemic exposure to topotecan lactone and myclosuppression was observed. CONCLUSIONS: In heavily pretreated children, the MTD for topotecan given by intermittent 30-min infusion for 5 days is 1.4 mg/m2 without GCSF and 2.0 mg/m2/day with GCSF. The dose-limiting toxicity is hematopoietic. Data from this study provide the basis for further studies of topotecan in children with cancer.

Adolescent↗
PubMed1996

Second malignancies after Ewing's sarcoma: radiation dose-dependency of secondary sarcomas.

BACKGROUND: An excess risk of second malignancies has been reported in survivors of Ewing's sarcoma. We examined a multiinstitutional data base to reevaluate the risk among survivors of Ewing's sarcoma and to identify possible causal factors. METHODS: Information was derived from a data base that included 266 survivors of Ewing's sarcoma. Cumulative incidence rates of second malignancies were calculated. Contributions of clinical features, type and dose of chemotherapy, and cumulative radiation dose to the risk of second malignancies were evaluated. RESULTS: After a median follow-up duration of 9.5 years (range, 3.0 to 30), 16 patients have developed second malignancies, which included 10 sarcomas (five osteosarcomas, three fibrosarcomas, and two malignant fibrous histiocytomas) and six other malignancies (acute myeloblastic leukemia, acute lymphoblastic leukemia, meningioma, bronchioalveolar carcinoma, basal cell carcinoma, and carcinoma-in-situ of the cervix). The median latency to the diagnosis of the second malignancy was 7.6 years (range, 3.5 to 25.7). The estimated cumulative incidence rates at 20 years for any second malignancy and for secondary sarcoma were 9.2% (SD = 2.7%) and 6.5% (SD = 2.4%), respectively. The cumulative incidence rate of secondary sarcoma was radiation dose-dependent (P = .002). No secondary sarcomas developed among patients who had received less than 48 Gy, while the absolute risk of secondary sarcoma was 130 cases per 10,000 person-years of observation among patients who had received > or = 60 Gy. CONCLUSION: The overall risk of second malignancies after Ewing's sarcomas is similar to that associated with treatment for other childhood cancers. The radiation dose-dependency of secondary sarcomas justifies modification in therapy to reduce radiation doses.

Adolescent↗
PubMed1996

Escalating systemic exposure of continuous infusion topotecan in children with recurrent acute leukemia.

PURPOSE: To determine the maximum-tolerated systemic exposure (MTSE) and exposure-limiting toxicity of continuous infusion topotecan in children with recurrent acute leukemia. PATIENTS AND METHODS: Patients received escalating levels of topotecan systemic exposure as measured by steady-state topotecan lactone concentration (Css). Samples obtained within the first 24 hours were measured by high-pressure liquid chromatography (HPLC) for topotecan. A two-compartment model was fit to the data using a Bayesian algorithm. Css was calculated for each patient; if it differed by more than 20% of target, a new dosage was begun within 6 hours. Follow-up concentrations were obtained as well as serial plasma samples postinfusion. Toxicity and evidence of activity were assessed after each course. RESULTS: Thirteen boys and five girls received 23 courses of topotecan. Target Css ranged from 1.0 to 5.3 ng/mL (topotecan doses, 0.5 to 3.3 mg/m2/d). Nineteen of 23 courses were within +/- 20% of target after adjustment (range, 77% to 139%). The MTSE was 4.0 ng/mL, and mucositis was exposure-limiting at 5.3 ng/mL. A significant relation between topotecan lactone Css and the severity of mucositis was observed. Myelosuppression was experienced but was not considered exposure-limiting. One complete response and one partial response were noted. CONCLUSION: The MTSE for continuous infusion topotecan was 4.0 ng/mL. Responses were noted at Css comparable to those producing responses in a severe combined immunodeficiency (SCID) mouse model. Further studies of topotecan are warranted.

Acute Disease↗
PubMed1996

Fractures in children treated with radiotherapy for soft tissue sarcoma.

There is a clear association between multimodal therapy for bone tumors and the development of skeletal complications; however, this has not been addressed in children with soft tissue sarcomas. We reviewed records of the 70 children treated for soft tissue sarcoma of the lower extremity at St. Jude Children's Research Hospital between 1962 and 1991. Of the 12 patients who received radiation after surgical excision of their tumors, three subsequently developed fractures. Two of the three had also received chemotherapy. Our findings indicate that, although the risk of fracture after therapy for soft tissue sarcoma may be multifactorial, radiation may play a significant role. Minimizing the size of surgical incisions, improving radiotherapy techniques, maximizing chemotherapy, and emphasizing physical therapy and appropriate follow up can all serve to decrease long-term toxicities. Such optimal use of therapy could subsequently reduce side effects, such as osteoporosis and muscle and bone atrophy, that predispose patients to fractures.

Adolescent↗
PubMed1996

Ongoing clinical studies of ifosfamide for pediatric cancer in the United States.

This article gives highlights of ongoing pediatric solid tumor and leukemia trials in the United States that use ifosfamide in combination with mesna. These trials are being carried out both by large cooperative groups and single institutions. Some role for ifosfamide with mesna in the front-line treatment of sarcomas is assured. Neurotoxicity, nephrotoxicity, and other unusual toxicities are discussed.

Antineoplastic Agents↗
PubMed1995

Outcome of treatment for childhood cancer in black as compared with white children. The St Jude Children's Research Hospital experience, 1962 through 1992.

OBJECTIVE: To determine whether there is a racial difference in prognosis among childhood cancers. DESIGN: An overall (30-year) survival analysis by race was followed by separate studies for "early" and "recent" treatment eras, defined by time points at which significantly improved outcome was demonstrated for specific tumor types. Stratified analyses were performed to adjust for recognized prognostic features. SETTING: Pediatric oncology research and treatment center. PATIENTS: The study included 798 black and 4507 white children with newly diagnosed malignancies treated from January 1962 through June 1992. These patients were accepted for treatment regardless of their financial status and were enrolled on disease-specific protocols. RESULTS: Across the 30-year study period, black children had a significantly poorer rate of survival than white children (P < .001, log-rank test). In the early treatment era, a significant difference was seen for all forms of cancer combined (P < .001), with 10-year Kaplan-Meier estimates (+/- SE) of 37% +/- 3% for black children and 50% +/- 1% for white children. This difference largely reflected the poorer prognosis of black children with the most common childhood cancer, acute lymphoblastic leukemia. In the recent treatment era, there were no significant differences in treatment outcome by race for specific disease categories or for all forms of cancer combined. Ten-year survival rates were 67% +/- 6% for black children and 66% +/- 3% for white children, indicating a significantly greater improvement in the former group. CONCLUSION: With equal access to effective contemporary treatment, black children with cancer fare as well as white children when treated with protocol-based therapy at a pediatric oncology research center.

Adolescent↗
PubMed1995

Embryonal malignancies of unknown primary origin in children.

BACKGROUND: Little is known about embryonal malignancies of unknown primary origin in children. All such cases referred to a pediatric cancer center over a 30-year period were reviewed to delineate their clinical and prognostic features and to develop recommendations for evaluation and therapy. METHODS: Seventeen patients with embryonal malignancies of unknown primary origin were identified by reviewing the institutional solid tumor database. The medical records, imaging studies, laboratory records, and pathology reports for each patient were reviewed and tabulated. RESULTS: Pathology review confirmed the original histologic diagnosis in 15 of the cases. Final diagnoses after review were rhabdomyosarcoma (n = 9), neuroblastoma (n = 7), and Ewing's sarcoma (n = 1). At initial evaluation, an extensive array of radiologic studies revealed multiple abnormalities in 16 cases. Bone marrow sampling and urinary catecholamine analysis were valuable diagnostic tools. A primary site of origin was identified in five patients: by interval assessments during treatment in two cases, and at autopsy in three. Although the median survival was only 6 months, 3 patients are alive at 12, 15 and 17 years after diagnosis. CONCLUSIONS: An exhaustive search for a primary lesion appears unwarranted in children with disseminated embryonal malignancies. Tumor sampling should be adequate for the pathologic work-up to determine the definitive diagnosis. Although the chances of cure are slight, tumor specific therapy may improve the interval of disease control, the quality of life, and the possibility of long term survival.

Adolescent↗
PubMed1995

Malignant melanocytic lesions of unknown primary site in children and adolescents.

BACKGROUND: Metastatic melanoma with an unidentified primary site represents 4% of all newly diagnosed cases of malignant melanoma in adults. Little is known of the incidence and clinicopathologic features of this clinical entity in the pediatric population. METHODS: We reviewed all previously diagnosed cases of malignant melanoma in children and adolescents (< 21 years) who were treated at our institution and identified three patients who presented with metastatic melanocytic lesions with an unidentified primary site. RESULTS: This clinical presentation accounted for 9% of all malignant melanocytic lesions treated at our center over a 20-year period. The clinicopathologic features were similar to those seen in adults. Two patients died of progressive disease within two years of presentation; the third is alive and disease-free 18 years post-diagnosis. CONCLUSIONS: Although uncommon in the pediatric population, malignant melanoma should be considered in the differential diagnosis of poorly differentiated disseminated malignancy that involves lymph nodes or viscera with no identifiable primary tumor.

Adolescent↗
PubMed1995

Use of irradiation for therapy of retinoblastoma in children more than 1 year old: the St. Jude Children's Research Hospital experience and review of literature.

Fifteen children (> 1 year old at diagnosis) were treated for retinoblastoma (RB) with primary irradiation at St. Jude Children's Research Hospital between January 1963 and January 1992. Staging of the 19 treated eyes was as follows: Reese-Ellsworth (R-E) Groups I and II, n = 7; Group III, n = 3; Group IV, n = 1; Group V, n = 7; information on one globe is incomplete. Total dosage ranged from 25 to 45 Gy (median = 40 Gy) in fractions of 170-225 cGy delivered 5 x/week (n = 13) or 225-265 cGy delivered 4 x/week (n = 4 eyes) or x 5/week (n = 2 eyes). Treatment techniques included anterior field (n = 11) or lens-sparing technique (n = 8). One patient has died of progressive central nervous system (CNS) disease at 13 months; one patient succumbed to second malignant neoplasm within the irradiated field at 194 months; the remaining 13 patients remain alive from 27 to 301 months (median = 178 months). Local control with irradiation alone has been maintained in 12 eyes. Four eyes with local recurrence were salvaged using cryotherapy or reirradiation. Enucleation was required for three eyes for progressive disease at 4, 7, and 7 months postirradiation. Cataract formation was documented in nine eyes treated with anterior fields and in one patient treated with lens-sparing technique. At last follow-up, 7 patients had visual acuity of 20/100 or better. Radiation dose of 40 Gy appears to be adequate for local control of early stage RB (R-E Groups I-III and VB whose tumors are R-E Groups I-III) in patients > 1 year old. The results of this limited series which has lengthy follow-up is compared with the results of previously published data in an effort to define the benefits and disadvantages of the different treatment techniques which have been reported in the treatment of RB in children > 1 year old.

Cataract↗