Biomedical subjects

R Barakat

Publications and source records attributed to R Barakat.

At least 37 records · Page 2Linked to original sources

PubMed1995

Dose escalation of paclitaxel with high-dose cyclophosphamide, with analysis of progenitor-cell mobilization and hematologic support of advanced ovarian cancer patients receiving rapidly sequenced high-dose carboplatin/cyclophosphamide courses.

PURPOSE: We commenced a phase I study of escalating dose Taxol (paclitaxel; Bristol-Myers Squibb Co, Wallingford, CT) in addition to cyclophosphamide, to assess its impact on both antitumor efficacy and mobilization of peripheral-blood progenitor cells (PBP). PATIENTS AND METHODS: Induction therapy consisted of two cycles of cyclophosphamide 3.0 g/m2 plus escalating-dose Taxol (dose levels I to IV, 150, 200, 250, and 300 mg/m2, respectively) in cohorts of three, plus filgrastim granulocyte colony-stimulating factor [G-CSF]) and leukaphereses to harvest PBP, followed by four courses of rapidly cycled carboplatin and cyclophosphamide (1,000 and 1,500 mg/m2 per course, respectively), for which hematopoietic rescue was achieved with PBP. RESULTS: Sixteen patients completed all planned cycles of Taxol/cyclophosphamide. Fifty-four cycles of carboplatin/cyclophosphamide were given and rescued with PBP. The median interval between treatments for Taxol/cyclophosphamide courses was 14 days (range, 13 to 21). Twelve patients completed all planned cycles of carboplatin/cyclophosphamide. The median inter-treatment interval for carboplatin/cyclophosphamide courses when rescue was achieved with Taxol/cyclophosphamide-primed PBP was 17 days (range, 14 to 25). The median number of days to recovery of an absolute neutrophil count (ANC) greater than 0.5 was 8 (range, 5 to 12), and of self-sustaining platelet count greater than 20 x 10(9)/L, 11 (range, 8 to 15). There was one episode of fatal sepsis. Of 13 patients assessable for response, there were five patients with pathologic complete responses (38.5%), six patients with microscopic residual disease (46%), and two patients with pathologic partial responses, for an overall response rate of 100%. CONCLUSION: The addition of escalating-dose Taxol to high-dose cyclophosphamide does not compromise PBP mobilization. The use of PBP mobilized in this fashion provides reliable engraftment after sequential administration of high-dose carboplatin/cyclophosphamide. Toxicities produced with this approach are manageable. The response rates demonstrated are promising and warrant further evaluation.

Adenocarcinoma↗

PubMed1995

Schistosoma mansoni in the Nile Delta, Egypt. A large scale epidemiological study in Kafr El Sheikh Governorate.

This is an early descriptive report of the 'Epidemiology 123' project in Egypt which makes use of large probability sampling methods. These results focus on Schistosoma mansoni infection in the northern Nile Delta Governorate of Kafr El Sheikh. A probability sample of 18,777 persons, representing the rural population of the entire Governorate, was drawn. The sample was designed not to exclude villages based on location or presence of health care facilities and to include representation of the smaller ezbas or hamlets. The objective was to obtain detailed estimates on age and sex specific patterns of S. mansoni infection, and to provide a baseline for prospective studies. Stool specimens were examined by the Kato method. The estimated prevalence of S. monsoni infection in the rural population was 39.3% (SE +/- 3.3) in 44 villages and ezbas after weighing for the effects of the sample design. The estimated geometric mean egg count per gram stool (GMEC) was 72.9 (SE +/- 7.3). Prevalence and GMEC varied considerably by village and ezba, with ezbas having a significantly higher prevalence. Villages and ezba specific prevalence was strongly associated with GMEC (r2 = 0.61, p < 0.001). The prevalence of S. mansoni infection increased by age to 55.4% (SE +/- 3.2) at age 16, without significant change in the adult ages. There was no gender difference until age six, after which males were consistently higher until middle age, when the differences converged. The age and sex specific pattern of GMEC varied widely, however, when the GMEC data were collapsed into five year age groups, GMEC peaked at 81.5 (SE / + - 12.1) epg in the 10 to 14 year age group. These estimates provide the basis for evaluating control measures for reducing prevalence, intensity of infection, and transmission.

Adolescent↗

PubMed1995

Impact of population-based selective chemotherapy on prevalence and intensity of Schistosoma mansoni infections in the Nile Delta: Kafr El Sheikh.

The impact of selective treatment with praziquantel (40 mg/kg) on Schistosoma mansoni prevalence and intensity of infection in two annual follow-up examinations was measured. The target population was the entire rural area of the northern Nile Delta Governorate, Kafr El Sheikh, from which a probability sample was drawn. The sample included 44 villages and hamlets (ezba). Baseline prevalence was determined by the examination of stool by two Kato slides and all infected persons treated and reexamined one year later. Those found infected in the second round were treated and examined again one year later. The prevalence and geometric mean egg count declined across all ages in each follow-up (prevalence: 39.3% (SE +/- 3.3), 28.4% (SE +/- 2.6), and 22.4% (SE +/- 2.3), respectively; and GMEC: 72.9 (SE +/- 7.3), 52.5 (SE +/- 4.5), and 41.9 (SE +/- 2.4), respectively). Reduction in prevalence varied considerably by village and ezba and was strongly related to the proportion of the village or ezba population that was infected and treated (r2 = 0.29). This latter observation provides a rationale for the maximum application of chemotherapy in the endemic Nile Delta community.

Adolescent↗

PubMed1995

Patterns of infection, incidence and reinfection with Schistosoma mansoni in Nile Delta Governorate: Kafr El Sheikh.

Two annual follow-up measures of incidence, reinfection after treatment and reversion rates were estimated in a large prospective study of Schistosoma mansoni located in the northern Nile Delta of Kafr El Sheikh. Rates were estimated in a cohort established from a probability sample of the entire rural area of Kafr El Sheikh. Infection was determined by the examination of two Kato stool slides. The weighted first and second annual overall incidence rates were 20.4%, SE +/- 1.4 and 15.9%, SE +/- 1.4, respectively. Geometric mean egg counts in incident cases were 35.6 epg, SE +/- 1.2 and 31.0, SE +/- 1.6 in the first and second follow-ups. Incidence was strongly associated with first round prevalence (r2 = 0.34). Reinfection rates were higher: 33.4%, SE +/- 3.1 and 31.0%, SE +/- 2.1. Reinfection was associated with incidence (r2 = 0.32). Reversion rates were highest in children 0 to 4 years old (61.2%, SE +/- 18.1 and 78.5%, SE +/- 7.0, respectively) and increased from the first to second follow-up: 37.2%, SE +/- 3.4 and 47.0%, SE +/- 3.7, respectively. Patterns of these rates by village community, age and sex are also given over both follow-up examinations and comparison with limited data on rates of S. mansoni infection from previous studies, suggests a stable pattern of transmission over time in the Nile Delta.

Adolescent↗

PubMed1994

Phase II trial of docetaxel in patients with platinum-refractory advanced ovarian cancer.

PURPOSE: This phase II study was conducted to evaluate the efficacy and toxicity of docetaxel in the treatment of patients with platinum-refractory ovarian cancer. PATIENTS AND METHODS: Twenty-five patients with platinum-refractory advanced ovarian cancer were treated. Twenty of the patients had failed to respond to platinum-based front-line chemotherapy and five had failed to respond to platinum-based therapy repeated at relapse. One patient had received prior pelvic radiation therapy. Patients were required to have bidimensionally measurable disease. Docetaxel was administered at a dose of 100 mg/m2 intravenously (i.v.) over 1 hour every 21 days. Twenty patients received no corticosteroid premedication and five received premedication with corticosteroids and antihistamines. RESULTS: Eight of 23 assessable patients (35%) had a partial response (PR; 95% confidence interval, 16% to 57%). The median response duration was 5 months. Hospitalization for toxicity, predominantly neutropenic fever, occurred in 12 patients (48%) and 16% of courses. Anemia was common in the study population. Nonhematologic toxicities included alopecia, rash, fluid retention, diarrhea, peripheral neuropathy, and hypersensitivity reactions. CONCLUSION: Docetaxel demonstrates significant activity in patients with platinum-refractory advanced ovarian cancer. Routine premedication is recommended. Further investigations of this agent in ovarian cancer, including combinations with other active agents, appear indicated.

Adult↗

PubMed1994

Intraperitoneal Taxol (paclitaxel) in the management of ovarian cancer.

In an effort to examine the safety and pharmacology of the intraperitoneal (i.p.) delivery of paclitaxel, 25 patients (24 with ovarian cancer) were treated in a phase I dose escalation trial. The drug was administered in normal saline every 3 to 4 weeks, starting at a dose of 25 mg/m2. The dose-limiting toxicity at doses at or above 175 mg/m2 was abdominal pain. A 3-log pharmacokinetic advantage for peritoneal cavity exposure to paclitaxel, compared with the systemic compartment, was observed. High levels of drug persisted within the cavity for longer than 48 hours following a single treatment. In addition, significant paclitaxel concentrations were found in the systemic compartment after i.p. treatment, despite the pharmacokinetic advantage demonstrated for cavity exposure. Several patients exhibited clinical and laboratory evidence of an antitumor response. On the basis of these data, further exploration of a potential role for i.p. paclitaxel in the management of ovarian cancer appears justified.

Dexamethasone↗

PubMed1993

Intraperitoneal chemotherapy in the management of ovarian cancer.

During the past decade, intraperitoneal therapy of ovarian cancer has evolved from a pharmacologic model into an established treatment technique for women with this malignancy. Approximately 40% of patients with small-volume residual ovarian cancer (microscopic disease or macroscopic tumor, < or = 0.5 cm in maximum tumor diameter), after an objective response to initial organoplatinum-based systemic chemotherapy, may have a surgically documented complete response to platinum-based intraperitoneal chemotherapy. Patients who have not responded to systemic platinum administration rarely will respond to the drug given intraperitoneally, despite the presence of only small-volume residual disease when this regional treatment strategy is used. Other agents with antineoplastic activity after intraperitoneal administration in women with ovarian cancer include mitoxantrone, taxol, alpha-interferon and gamma-interferon, and interleukin-2. Although intraperitoneal therapy currently is being examined as a component of the initial chemotherapeutic program for patients with ovarian cancer, a precise role for regional drug delivery in this clinical setting remains to be defined.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

Epithelial ovarian cancer in the elderly. The Memorial Sloan-Kettering Cancer Center experience.

BACKGROUND: There is evidence of differences between older (> or = 65 years of age) and younger (< 65 years of age) women with ovarian cancer. METHODS: To evaluate differences in the care of older versus younger patients with ovarian cancer, a retrospective review was conducted of the records of 146 patients who had their initial surgery for ovarian cancer at the Memorial Sloan-Kettering Cancer Center from January 1987-January 1991. RESULTS: There was a significant difference in stage at presentation between the older (48 patients) and younger (98 patients) populations (Stage I/II: older 10%; younger 25%; P < 0.05). Although there was no statistically significant difference in the distributions of patients according to tumor grade between the two groups, 10% of the younger patients had ovarian cancer of low malignant potential, compared to only 2% of older patients (P < 0.1). Forty-six percent of the younger patients entered an intensive initial chemotherapy trial compared to only 17% of the older patients (P < 0.001), principally due to comorbid medical conditions (e.g., heart disease). Finally, whereas the relative number of younger to older patients with ovarian cancer undergoing initial surgery at this institution was 2:1, the relative number of totally new patients to the service (including referral for initial treatment or salvage programs) was 4:1 (P < 0.001), suggesting that older patients with ovarian cancer are less likely to be referred for secondary experimental programs than for initial treatment. CONCLUSIONS: These data suggest that there are major differences between the presentation and treatment strategies of older compared to younger patients with ovarian cancer.

Adult↗

PubMed1993

Evidence for persistence of mitoxantrone within the peritoneal cavity following intraperitoneal delivery.

In clinical trials examining the intraperitoneal (ip) administration of mitoxantrone as therapy of platinum-refractory small-volume residual ovarian cancer, the characteristic "blue color" of the agent has been demonstrated to stain the surface of the peritoneal cavity and to persist for > or = 1 month following the last course of therapy. To determine if this blue staining material contains potentially cytotoxic concentrations of mitoxantrone, we analyzed tissue obtained at exploratory laparotomy in six women who had last received the agent administered ip from 6-22 weeks prior to surgery. Concentrations of mitoxantrone ranged from < 0.1 to 13.8 micrograms/g of tissue examined. Since any mitoxantrone present on the peritoneal surface will be highly protein bound, any residual drug may not have cytotoxic potential. The dose-response curves of mitoxantrone in a human clonogenic cytotoxicity assay against the RPMI 2780/S human ovarian cell line were virtually identical when the cells were incubated in either 5 or 50% fetal bovine serum, suggesting that protein binding will not significantly impair mitoxantrone-induced tumor cell killing. We conclude that the ip administration of mitoxantrone may lead to prolonged exposure of surface tumor to the high local concentrations of the active cytotoxic agent. This effect may contribute significantly to the antineoplastic potential of ip mitoxantrone in patients with small-volume residual ovarian cancer.

Dose-Response Relationship, Drug↗

PubMed1993

The use of recombinant human erythropoietin to prevent carboplatin-induced anemia.

Anemia is a frequent and potentially serious toxicity associated with the use of carboplatin, particularly when this agent is administered in the salvage setting. In an effort to evaluate a possible role for human erythropoietin (rh-E) in preventing or minimizing carboplatin-induced anemia we analyzed the impact of the agent on anemia and transfusion requirements of women with ovarian cancer who were treated on one of two nonrandomized trials employing identical second-line carboplatin-based intraperitoneal regimens, with the only difference in the regimens being the addition of rh-E (Study 1, without rh-E; Study 2, with rh-E). There was a statistically significant difference in the incidence of documented nadir hemoglobin levels of < 9 g/dl (Study 1, 60%; Study 2, 13%; P < 0.005) and < 8 g/dl (Study 1, 33%; Study 3, 6%; P < 0.05). We also observed a threefold reduction in transfusion requirements with the use of rh-E (Study 1, 23%; Study 2, 6%), but this difference was not statistically significant with the limited sample size evaluated. In this nonrandomized comparison of two identical chemotherapy programs we have demonstrated that rh-E significantly reduced the incidence and severity of anemia associated with carboplatin-based chemotherapy. A randomized trial examining the potential impact of rh-E on carboplatin-induced anemia and transfusion requirements is warranted.

Adult↗

PubMed1993

Salvage intraperitoneal mitoxantrone therapy of ovarian cancer: influence of increasing the volume of treatment.

Despite the demonstrated activity of intraperitoneal mitoxantrone in patients with small volume-platinum-refractory ovarian cancer, previous reports have revealed that many patients fail to achieve adequate distribution of the cytotoxic drug throughout the peritoneal cavity when delivered in a "standard" 2-liter treatment volume. In an effort to improve the distribution and therapeutic efficacy of intraperitoneal mitoxantrone, 22 patients with platinum-refractory ovarian cancer were treated with the drug at a dose of 10 mg/m2 given in 2 liters of normal saline followed by an additional 1-2 liters every 2 weeks for eight cycles. The surgically defined complete response rate in 17 patients evaluable for response with platinum-refractory ovarian cancer was 24%, with an overall response rate of 29%. Of 18 in which the influence of treatment volume could be examined (4 patients developed catheter failure), 12 (67%) were able to tolerate a 4-liter treatment volume for > 80% of courses, with a total of 15 patients (83%) receiving treatment with a minimum of a 3-liter treatment volume. We conclude that it is possible to safely increase the intraperitoneal treatment volume to 3-4 liters in most patients undergoing this therapeutic strategy. While the impact on therapeutic efficacy of expanding the volume employed for cytotoxic drug delivery remains to be defined, in theory this approach may optimize the opportunity for agents achieving high-intraperitoneal concentrations to produce their maximal cytotoxic effect.

Adult↗

PubMed1993

Impact of age on survival of patients with ovarian cancer.

In an effort to determine if there are significant differences in outcome between elderly (> or = 65 years of age) and younger (< 65 years of age) women with epithelial ovarian cancer we examined the survival of patients with this malignancy who underwent their initial surgical evaluation at the Memorial Sloan-Kettering Cancer Center from January 1987-January 1991. The actuarial median overall survival for the 98 younger patients has not been reached but will exceed 4 years, compared to a median survival of 24 months for the 48 elderly patients (P < 0.0001). For individuals with advanced (stages 3-4) disease, excluding patients with tumors of low malignant potential, the median survival for the younger patient population has also not been reached and will exceed 4 years, compared to 21 months for the older population (P < 0.0001). Even in the limited number of patients with local/regional (stages 1-2) ovarian cancer, there was a statistically significant superior survival for the younger group of patients (P < 0.02). With a single exception, all deaths were believed to be due principally to disease progression, rather than to an unrelated comorbid medical event. We conclude that elderly patients with ovarian cancer experience a significantly inferior survival than younger individuals with this malignancy. Evaluation of larger populations will be required to confirm the results of this analysis and to probe for explanations for the striking survival differences we have observed.

Adult↗

PubMed1993

Mitomycin-C plus a 3-day continuous intravenous infusion of 5-fluorouracil: an inactive salvage regimen for platinum-resistant ovarian carcinoma.

In a Phase II trial, patients with refractory ovarian cancer were given 10 mg/m2 mitomycin-C i.v. every 8 weeks and 1000 mg/m2/day 5-fluorouracil for 3 consecutive days by continuous intravenous infusion repeated every 4 weeks. Sixteen heavily pretreated patients with platinum-resistant disease were treated and no major responses were observed. Only 2 patients required subsequent dose reduction for myelotoxicity. No sign of gastrointestinal toxicity was seen. This regimen is inactive as salvage treatment for refractory ovarian cancer.

Adult↗

PubMed1993

Evidence supporting the superiority of intraperitoneal cisplatin compared to intraperitoneal carboplatin for salvage therapy of small-volume residual ovarian cancer.

PURPOSE: To examine the relative efficacy of cisplatin-based intraperitoneal (IP) therapy versus carboplatin-based IP therapy as salvage treatment of small-volume residual ovarian cancer. PATIENTS AND METHODS: We retrospectively examined the surgically defined response rates of patients with ovarian cancer treated at the Memorial Sloan-Kettering Cancer Center on four organoplatinum-based salvage IP trials (cisplatin/etoposide, cisplatin/cytarabine, carboplatin/etoposide, carboplatin/etoposide + recombinant human erythropoietin). Additional criteria for inclusion in this analysis were: (a) small-volume residual disease (microscopic disease only or largest residual tumor mass < or = 0.5 cm) when IP therapy was initiated; (b) prior response to organoplatinum-based systemic therapy; (c) laparotomy evaluation for response to the IP salvage program. RESULTS: The surgically documented complete response rate for patients with microscopic disease treated with cisplatin-based or carboplatin-based therapy was 46% (6/13) versus 38% (6/16), respectively (P > 0.25). In contrast, the surgically documented overall and complete response rates for patients with small-volume macroscopic disease treated with cisplatin or carboplatin were 71% (12/17) versus 32% (6/19) (P < 0.05, chi 2 test with Yates' correction), and 41% (6/17) versus 11% (2/19) (p < 0.1), respectively. CONCLUSION: In agreement with experimental data demonstrating that the concentration of platinum within tumor is higher following equimolar doses of cisplatin, compared to carboplatin, we have observed, in this retrospective analysis, a higher surgically documented response rate for patients with small-volume residual macroscopic ovarian cancer receiving salvage cisplatin-based IP therapy. While a randomized trial will be required to definitively address the question of the relative effectiveness of the two commercially available organoplatinum agents for IP treatment of ovarian cancer, our data suggest that cisplatin is the superior agent for regional therapy in this disease.

Carboplatin↗

PubMed1993

Diethyldithiocarbamate chemoprotection of carboplatin--induced hematological toxicity.

Carboplatin therapy has a more favorable toxicity profile than cisplatin and, given in appropriate doses, is equivalent in efficacy to cisplatin for suboptimal ovarian cancer. However myelosuppression frequently curtails therapy with carboplatin. Diethyldithiocarbamate (DDTC) is a thiol compound and heavy-metal-chelating agent that has been shown to protect against carboplatin-induced bone marrow suppression in animal models. This pilot study was undertaken to evaluate the ability of DDTC to ameliorate the degree and/or duration of myelosuppression from carboplatin chemotherapy in patients with relapsed ovarian cancer. Ten patients who had previously demonstrated a response to platinum-based chemotherapy, were treated with single-agent intravenous carboplatin 400 mg/m2 administered over 30-60 min every 4 weeks. Patients received their first cycle of carboplatin without DDTC, and their second cycle with DDTC. DDTC at 600 mg/m2 was infused over 3 h commencing 30 min prior to carboplatin and was well tolerated. Treatment with DDTC did not decrease the degree of leukopenia or thrombocytopenia associated with carboplatin chemotherapy, nor did it decrease the duration of myelosuppression. This clinical study demonstrates no evidence of a bone-marrow-protective effect for this dose and schedule of DDTC in patients receiving carboplatin chemotherapy.

Adenocarcinoma, Papillary↗

PubMed1993

Phase II trial of zeniplatin (CL 286,558), a new patinum compound, in patients with advanced ovarian cancer previously treated with organoplatinum-based therapy.

There is a critical need to find new chemotherapeutic agents that are active in platinum-refractory ovarian cancer. A phase II trial of zeniplatin (CL 286,558), a third-generation platinum compound, was conducted in 31 patients with advanced ovarian cancer to examine the safety and activity of the agent when used as a salvage treatment in individuals previously exposed to organoplatinum-based therapy. In general the drug was well tolerated, with moderate emesis and bone marrow suppression being observed in most patients. An unexpected side-effect was significant fever, of unknown etiology, which was noted in 16% of patients. Out of 20 patients, 2 (10%; 95% confidence intervals: 1%-32%) with clinically defined platinum-refractory disease achieved a partial response. Unfortunately, although we have defined definite but modest activity for zeniplatin in platinum-refractory ovarian cancer, further development of this drug has been discontinued because of the severe renal toxicity observed in other clinical trials of this cytotoxic agent.

Adult↗

PubMed1993

Intraperitoneal administration of Taxol in the management of ovarian cancer.

The safety and pharmacology of the intraperitoneal administration of Taxol was evaluated by treatment of 25 patients (24 with ovarian cancer) on a phase I dose-escalation trial. The drug was delivered in 2 L of normal saline every 3 to 4 weeks, with a starting dose of 25 mg/m2. The dose-limiting toxicity was abdominal pain at Taxol doses greater than 125 mg/m2. A 3-log pharmacokinetic advantage for peritoneal cavity exposure to Taxol, compared to the systemic compartment, was demonstrated following intraperitoneal delivery. In addition, high levels of Taxol persisted within the cavity for more than 48 hours following a single treatment. Despite the major pharmacokinetic advantage for peritoneal cavity exposure, significant concentrations of Taxol were demonstrated within the systemic compartment after intraperitoneal treatment. Several patients exhibited clinical and laboratory evidence of an antitumor response. Further exploration of a possible role for the intraperitoneal administration of Taxol in the management of ovarian cancer appears indicated.

Female↗

PubMed1993

An epidemiological assessment of Ambrosia maritima on the transmission of schistosomiasis in the Egyptian Nile Delta.

Ambrosia maritima (Damsissa), a proven molluscicide, was investigated in a seven year epidemiological trial in four villages in the northern Egyptian Nile Delta. Schistosoma mansoni prevalence and other measures of infection were initially high in the four villages before the trial began. Two villages were used to test the impact of A. maritima application both on snail populations and on infection in the village population. Two villages were held as controls and not treated with A. maritima. The entire population of all four villages was included in the study. Prevalence and other measures of infection fell dramatically following treatment with praziquantel 40 mg kg-1 body weight. On annual follow ups, the prevalence of infection and geometric mean egg counts began to increase back to original levels in both test and control villages; age adjusted incidence rates were lower in one test village, but higher in the other when compared to the control villages. Snail populations were destroyed in the treated canals and drains located near the test villages. The lack of a clear epidemiologic impact is discussed.

Adolescent↗