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Biomedical subjects

C B Pratt

Publications and source records attributed to C B Pratt.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1995

Imaging features of ovarian metastases from colonic adenocarcinoma in adolescents.

This paper describes the imaging features of ovarian metastases from adenocarcinoma of the colon in adolescent females. We reviewed retrospectively abdominal and pelvic computed tomographic and pelvic ultrasound examinations, histologic slices, and clinical charts of six adolescent females with ovarian metastases secondary to adenocarcinoma of the colon. One patient had ovarian metastasis at presentation and was presumed to have a primary ovarian tumor. The ovarian metastases were either solid (n = 3), complex with both solid and cystic components (n = 2), or multilocular cysts (n = 1). The ovarian lesions were large, ranging from 6 cm to 18 cm in diameter. Colorectal carcinoma in adolescent females is frequently associated with ovarian metastases. One imaging characteristic differs in adult and adolescent ovarian metastases, although they do have features in common: in adolescents, a smaller proportion of colorectal ovarian metastases are multicystic (17%) compared with the adult series (45%). These lesions are frequently large and may be complex, multicystic, or solid. Although it is a rare disease, the differential diagnosis of adnexal masses in adolescent females should include ovarian metastases from adenocarcinoma of the colon.

Adenocarcinoma↗
PubMed1995

A phase I study of sulofenur in refractory pediatric malignant solid tumors.

The diarylsulfonylureas have shown promise in xenograft models of childhood cancer. Sulofenur has been evaluated in phase I and II trials in adults with a variety of solid tumors, but the toxicity and maximum tolerated dose of sulofenur in children and adolescents have not been determined. In a phase I study, sulofenur was administered to 13 patients with refractory pediatric malignant solid tumors. Daily dosages of 640, 800, and 960 mg/M2 in two divided oral doses were given for 5 consecutive days each week for 3 weeks. The primary and dose-limiting toxicity was methemoglobinemia, which occurred at all dose levels and required transfusions of packed red blood cells, administration of methylene blue, or both. Anemia and, less frequently, leukopenia and thrombocytopenia were also observed. A maximum tolerated daily dosage was not defined, as methemoglobinemia was noted with each dosage level. There were no measurable tumor responses. The toxicity of this agent makes it unattractive for further investigation in pediatric patients.

Adolescent↗
PubMed1995

Ifosfamide/carboplatin/etoposide (ICE) for recurrent malignant solid tumors of childhood: a Pediatric Oncology Group Phase I/II study.

PURPOSE: The combination of ifosfamide (I) and etoposide (E) was useful in salvaging patients with recurrent/resistant malignant solid tumors of childhood. Carboplatin (C), active against a number of pediatric cancers, was added to I and E to form a three-drug combination called ICE to improve the response rate. PATIENTS AND METHODS: ICE, consisting of I 1.5 g/m2 plus E 100 mg/m2 i.v.q.d. x 3 plus C i.v. on day 3 only, was given in 21-28-day intervals. C was started at 300 mg/m2, and the dose was escalated in 25% increments, with three evaluable patients treated at each level. RESULTS: Ninety-two patients were enrolled in this phase I/II study between July 1990 and April 1993. A total of 331 courses of ICE was administered. Median courses of ICE received were three (range, 1-16). The maximum tolerated dose (MTD) for C when used in combination was found to be 635 mg/m2. The response rate for ICE at the MTD for C was complete response (CR) 26% and CR + partial response (PR) 53%. The response was even better in those who received C at the MTD: 32% achieving a CR and 63% a CR + PR. Pancytopenia was the dose-limiting toxicity. Thirteen episodes of bacterial infection were reported, none fatal. Only one patient developed a Fanconi-like syndrome. CONCLUSION: The MTD of C when used with I and E was found to be 635 mg/m2. The overall CR + PR rate for all patients treated at all C dose levels was 53%. Best responses were seen in non-Hodgkin's lymphoma, neuroblastoma, soft tissue sarcomas, and Wilms' tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Subsequent malignancies in children and adolescents after treatment for Hodgkin's disease.

PURPOSE: We assessed the cumulative risk of malignancies following treatment for Hodgkin's disease in childhood and adolescence and investigated related patient and treatment characteristics. PATIENTS AND METHODS: Medical records of 499 Hodgkin's disease patients treated between 1962 and 1993 were reviewed. There were 385 adolescents (> or = 10 years of age at diagnosis) and 114 preadolescents (< 10 years). Most patients (n = 346) were treated with radiation plus multiagent chemotherapy, while 30 received only chemotherapy and 123 only radiation therapy. Radiation doses ranged from 20 to 42 Gy. RESULTS: At a median follow-up duration of 9 years (range, 0.1 to 27.4), 25 patients have had second malignancies: 19 solid tumors, four acute nonlymphoblastic leukemias (ANLLs), 1 non-Hodgkin's lymphoma (NHL), and one chronic myeloid leukemia (CML). Three patients have had a third malignancy. The estimated cumulative risk of second malignancies increased from 1.5% at 5 years to 7.7% at 15 years. All but two of the patients with second malignancies were > or = 10 years of age at initial diagnosis, which reflects the higher risk among patients treated for Hodgkin's disease as adolescents (P = .01). Second malignancies were more common among female patients (P = .0002), even when those breast cancer were excluded (P = .007), and in those treated for recurrent Hodgkin's disease (P = .02). Patients with ANLL/NHL were older at diagnosis of Hodgkin's disease than those with solid tumors, (median age, 18.3 v 13.8 years; P = .04). There was no difference between groups treated with radiation therapy alone, chemotherapy alone, or radiation plus multiagent chemotherapy. CONCLUSION: Adolescents treated for Hodgkin's disease are at greater at risk of second malignancies than younger patients. Overall, adolescent females treated for recurrent Hodgkin's disease appear to be at greatest risk, while preadolescents appear to be protected from this late complication.

Adolescent↗
PubMed1994

Phase II study of 5-fluorouracil/leucovorin for pediatric patients with malignant solid tumors.

BACKGROUND: 5-Fluorouracil (5-FU) activity for various carcinomas of adults has been enhanced through the synergistic effect of leucovorin. Few pediatric studies of 5-FU in pediatric patients have been previously reported. METHODS: Fifty-eight patients were treated with a 4-hour infusion of leucovorin, 400 mg/m2, administered daily for 5 days every 3-4 weeks. 5-Fluorouracil was administered by bolus injection 1 hour into each leucovorin infusion. Eleven adolescent patients with colorectal carcinoma, Stage 3 or 4, were treated with therapeutic intent, and other patients with a variety of drug-resistant pediatric solid neoplasms received similar treatment. RESULTS: Patients with measurable disease of colorectal carcinoma responded favorably to 5-FU/leucovorin. Stable disease activity was seen with other tumor types. Specifically, there were no objective responses in 12 patients with Ewing's Sarcoma or 11 with osteosarcoma. There were 4 deaths in this study from causes related to toxicity. Nonfatal grade 3/4 toxicities included mucositis, rash, myelosuppression, nausea, vomiting, diarrhea, and infection. CONCLUSION: The authors do not plan further evaluation of 5-FU/leucovorin in additional pediatric patients with colon cancer or other heavily pretreated malignant solid tumors and are presently treating their patients with colon carcinoma with 5-FU/leucovorin/interferon-alpha 2a.

Adolescent↗
PubMed1994

Pediatric brachytherapy. The St. Jude Children's Research Hospital experience.

BACKGROUND: The use of interstitial, intracavitary, and permanent placement of radioactive isotopes has become a common practice in adult oncology patients based on numerous reports indicating improved local control and survival when used. These same irradiation techniques and treatments have been infrequently used for children with malignant disease despite known dose localization properties that allow for highly focal irradiation delivery with rapid reduction of the dose in nearby normal tissues. The noted benefit of decreased late complications noted in the adult series is also attractive, especially when considering the treatment of children. METHODS: Between May, 1981 and December 15, 1992, 46 children with non-CNS primary malignancy received 50 brachytherapy applications for primary therapy (n = 11 sites), as a boost in conjunction with external beam irradiation (n = 16 sites), or as treatment of recurrent disease or a second malignant neoplasm in a previously irradiated region that precluded further external irradiation or for metastatic disease (n = 23 sites). The most common tumor histologies were rhabdomyosarcoma (n = 14), soft tissue sarcoma (n = 10) and retinoblastoma (n = 10). Patient age at implantation ranged from 8 weeks to 24 years; follow-up maintained in all patients and has ranged from 2-115 months (median, 39 months). RESULTS: Forty-three of 50 sites receiving brachytherapy have maintained continuous disease free intervals, ranging from 2 to 115 months postimplantation (median, 41 months). The seven local failures occurred 2-20 months postimplant (median, 6 months). Severe complications occurred in 12 patients, two which were life threatening but resolved without further incident. CONCLUSIONS: Based on this ongoing clinical investigation, the authors recommend brachytherapy for selected pediatric malignancies and continue to evaluate the various factors associated with local control, local failures, and complications.

Adolescent↗
PubMed1994

Phase I study of escalating targeted doses of carboplatin combined with ifosfamide and etoposide in treatment of newly diagnosed pediatric solid tumors.

BACKGROUND: The combination of carboplatin, ifosfamide, and etoposide has shown promising activity in a variety of relapsed childhood solid tumors but has not been studied in newly diagnosed patients. PURPOSE: The tolerance for and activity of escalating targeted doses of carboplatin combined with ifosfamide and etoposide (ICE) were assessed in children with advanced germ cell tumors or other rare solid tumors for which no standard therapy exists. METHODS: Fifteen children with newly diagnosed solid tumors received ICE chemotherapy. Individualized carboplatin doses were calculated to achieve a target area under the concentration x time curve (AUC) and adjusted for the glomerular filtration rate (estimated by 99mTc-labeled diethylene-triamine pentaacetic acid clearance). Cohorts of at least three patients received carboplatin at an initial target AUC of 6 mg.min/mL, with escalations of 2 mg.min/mL in subsequent cohorts. Carboplatin was given on day 1, followed by ifosfamide at 2 g/m2 per day and etoposide at 100 mg/m2 per day on days 2 through 4. All patients received at least two courses of therapy in the absence of progressive disease, and as many as eight courses could be given. RESULTS: The 15 patients received a total of 46 assessable courses of ICE. Myelosuppression was the dominant toxicity; 30 courses (67%) resulted in hospitalization for febrile neutropenia. Neutropenia was dose limiting at the carboplatin target AUC of 12 mg.min/mL. One complete and eight partial responses were seen in the 14 assessable patients; two additional patients had at least partial responses documented at surgery or autopsy. Six patients are without evidence of disease at a median of 548 days after diagnosis. CONCLUSION: ICE chemotherapy, with the carboplatin dose based on a target AUC of 10 mg.min/mL, is tolerable and has significant activity in a variety of rare malignancies, including extragonadal germ cell tumors. IMPLICATIONS: The combination of carboplatin, etoposide, and ifosfamide holds promise in the treatment of rare pediatric malignancies.

Antineoplastic Combined Chemotherapy Protocols↗