Prevention of radiation-induced central nervous system toxicity: a role for amifostine?
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PURPOSE: To review the role of amifostine (WR-2721) in ameliorating radiation-induced central nervous system (CNS) toxicity. MATERIALS AND METHODS: Literature review and presentation of preliminary animal experiments designed to test the efficacy of both intrathecal and subcutaneous application of amifostine. RESULTS: Despite its inability to cross the blood-brain barrier, amifostine appears promising because it protects blood vessels against radiation-induced damage. Vascular damage is one of the most important components in the development of CNS toxicity after radiotherapy. Furthermore, the increased permeability of the blood-brain barrier during fractionated radiotherapy might allow penetration of amifostine. Three animal studies with systemic administration found positive results after brain irradiation with different fractionation schedules, total doses and amifostine doses. One study where amifostine was given after radiotherapy showed no protection, suggesting that the timing of the drug application is crucial. Further data suggest that either intrathecal or systemic administration might protect the spinal cord as well. In our experience with spinal cord irradiation, systemic administration was more effective than intrathecal. Regarding CNS protection, the optimum dose of amifostine has yet to be determined. CONCLUSION: Several independent experiments provided preliminary evidence that modulation of the radiation response of the CNS in vivo by systemic administration of amifostine is possible and feasible. Additional studies are warranted to investigate the protective effect with differing regimens of administration, more clinically relevant fractionation regimens and longer follow-up. (+info)
Randomized trial of amifostine in locally advanced non-small-cell lung cancer patients receiving chemotherapy and hyperfractionated radiation: radiation therapy oncology group trial 98-01.
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PURPOSE: To test the ability of the cytoprotectant, amifostine, to reduce chemoradiotherapy-induced esophagitis and evaluate its influence on quality of life (QOL) and swallowing symptoms. PATIENTS AND METHODS: A total of 243 patients with stage II to IIIA/B non-small-cell lung cancer received induction paclitaxel 225 mg/m(2) intravenously (IV) days 1 and 22 and carboplatin area under the curve (AUC) days 1 and 22, followed by concurrent weekly paclitaxel (50 mg/m(2) IV) and carboplatin (AUC 2), and hyperfractionated radiation therapy (69.6 Gy at 1.2 Gy bid). Patients were randomly assigned at registration to amifostine (AM) 500 mg IV four times per week or no AM during chemoradiotherapy. Beyond standard toxicity end points, physician dysphagia logs (PDLs), daily patient swallowing diaries, and QOL (EORTC QLQ-C30/LC-13) were also collected. Swallowing AUC analyses were calculated from patient diaries and PDLs. RESULTS: A total of 120 patients were randomly assigned to receive AM, and 122, to receive no AM (one patient was ineligible); 72% received AM per protocol or with a minor deviation. AM was associated with higher rates of acute nausea (P = .03), vomiting (P = .007), cardiovascular toxicity (P = .0001), and infection or febrile neutropenia (P = .03). The rate of >/= grade 3 esophagitis was 30% with AM versus 34% without AM (P = .9). Patient diaries demonstrated lower swallowing dysfunction AUC with amifostine (z test P = .025). QOL was not significantly different between the two arms, except for pain, which showed more clinically meaningful improvement and less deterioration at 6 weeks follow-up (v pretreatment) in the AM arm (P = .003). The median survival rates for both arms were comparable (AM, 17.3 v no AM, 17.9 months; P = .87). CONCLUSION: AM did not significantly reduce esophagitis >/= grade 3 in patients receiving hyperfractionated radiation and chemotherapy. However, patient self-assessments suggested a possible advantage to AM that is being explored with modified dosing route strategies. (+info)
Triplet chemotherapy with docetaxel, gemcitabine and liposomal doxorubicin, supported with subcutaneous amifostine and hemopoietic growth factors, in advanced non-small cell lung cancer.
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The activity of a triplet of chemotherapeutic drugs, namely docetaxel, gemcitabine and liposomal doxorubicin, was investigated in patients with advanced non-small cell lung cancer. The regimen was supported with amifostine cytoprotection (1000mg injected subcutaneously) and hemopoietic growth factors (rhuG-CSF and rhuEPO) in an attempt to minimize the substantial toxicity reported in previous studies investigating docetaxel/gemcitabine chemotherapy. Twenty chemotherapy- naive patients with advanced non-small cell lung cancer (NSCLC) (18 with stage IV and 2 with stage IIIb) were recruited. None of the patients presented with grade 3-4 hematological or non-hematological toxicity. Palmar-plantar erythrodysesthesia grade 2 was noted in 6/20 (30%), mucositisloesophagitis grade 2 in 3/20 (15%) and mild alopecia in 6/20 (30%) patients. No case of interstitial pneumonia was noted. The overall response rate (complete and partial) in 18 evaluable patients was 33% (6/18), with 1/18 (5%) patients achieving complete response. The median survival was 11 months. The efficacy of the regimen was as high as the one reported in gemcitabine/docetaxel studies, but the toxicity was remarkably lower. Amifostine may have contributed to the better tolerance profile observed. (+info)
Amifostine has an inhibitory effect on the radiation-induced p53-branched cascade in the immature mouse ovary.
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The organic thiophosphate, amifostine, is a promising pharmacological compound showing selective protection in many tissues against the toxic side-effects of radiation and cytotoxic drugs. The aim of the present study was to assess the radioprotective effects of amifostine on ovarian follicles. Three-week-old female mice, with or without pretreatment with amifostine, were irradiated with 6.42 Gy of gamma-ray. Reduced proliferation of granulosa cells was verified with BrdU staining and the incidences of follicular degeneration increased in ovarian follicles in the gamma-ray-irradiated mice compared to that of the control or amifostine-treated group. Biochemical changes caused by gamma-irradiation provoked a rise of p53 and Bax protein and a decline of the inactive form in caspase-3 and PARP protein. Caspase-3 and PARP cleaved into active peptides during apoptosis. This process was confirmed by the result of this study, which was that the amount of the stable form decreased immediately after irradiation. In the amifostine treatment group before irradiation, the increased rate of p53 and Bax was suppressed, particularly in the LDs-treated group. The relationship between PARP and caspase-3 levels showed the effect of amifostine exposure before irradiation. In conclusion, amifostine had an inhibitory effect on ovarian programmed cell death induced by gamma-ray, affecting the expression of apoptotic signaling molecules and the level of proliferation of the granulosa cells. (+info)
Induction of caspase 3 activity, bcl-2 bax and p65 gene expression modulation in human acute promyelocytic leukemia HL-60 cells by doxorubicin with amifostine.
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The influence of amifostine alone and in combination with doxorubicin, cytarabine, and etoposide on the cell growth and on bcl-2, bax and p65 gene expression was investigated in human acute promyelocytic leukemia cell line HL-60. No or very little influence of the exposure of HL-60 cells to amifostine (10(-6) to 10(-2) M) on cell proliferation was shown. Proliferation of HL-60 cells exposed to doxorubicin, cytarabine, or etoposide dropped down with increasing doses of these drugs. Only in the case of doxorubicin, more effective inhibition of HL-60 cell growth was observed when combination of doxorubicin, cytarabine or etoposide with amifostine was used. Cytotoxic effect of cytarabine or etoposide was not reduced by amifostine. The lowering of the cytotoxic index (IC50) was observed only when HL-60 cells were preincubated with amifostine followed by doxorubicin treatment. IC50 was estimated as 2.1 x 10(-7) M and 0.9 x 10(-7) M for doxorubicin and doxorubicin with amifostine, respectively. This effect was accompanied by the induction of caspase 3 activity. HL-60 cells treated with doxorubicin alone showed about 35-fold increase in caspase 3 activity. The enzyme activity was stimulated by combination of doxorubicin with amifostine up to 94 times. Furthermore, the expression of bcl-2 and bax genes involved in apoptosis as well as tumor-associated p65 gene were determined. Semiquantitative reverse transcriptase polymerase chain reaction showed a decrease in bcl-2 and an increase in bax and p65 expression in HL-60 cells treated with doxorubicin in combination with amifostine when compared with the cells treated only with doxorubicin. Amifostine may potentiate doxorubicin therapeutic efficiency in human acute promyelocytic leukemia cells. (+info)
Amifostine does not protect against the ototoxicity of high-dose cisplatin combined with etoposide and bleomycin in pediatric germ-cell tumors: a Children's Oncology Group study.
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BACKGROUND: High-dose cisplatin combined with etoposide and bleomycin (HDPEB) improves event-free survival (EFS) in advanced pediatric germ-cell tumors (PGCT), but has significant ototoxicity. Amifostine appears to protect against toxicity. The authors combined amifostine with HDPEB and evaluated the efficacy and toxicity, specifically whether ototoxicity decreased. METHODS: Eligibility criteria included age < 15 years and unresectable Stage III/IV extracranial, extragonadal PGCT. Patients received bleomycin 15 IU/m(2) on Day 1, then etoposide 100 mg/m(2) per day, amifostine 825 mg/m(2) per day, and cisplatin 40 mg/m(2)per day on Days 1-5, intravenously. The cycles were repeated every 3-4 weeks with imaging evaluation after 4 cycles. Patients with residual radiographic abnormalities underwent resection. Patients with residual tumor received two additional HDPEB cycles. Hearing evaluations were required at diagnosis and after two and four cycles. Audiologic results were reviewed and compared with historical controls treated with HDPEB. RESULTS: Twenty-five eligible patients were enrolled between April 2000 and April 2002. Their median age was 1.6 years (range, 0.64-13.9 years), 17 patients were female, 11 had metastases, and 24 had a yolk sac carcinoma component histologically. Primary sites included sacrococcygeal area/pelvis (n = 15), vagina (n = 5), and other (n = 5). Two-year EFS and overall survival were 83.5% +/- 12.8% and 85.6% +/- 12.3%, respectively. Eight patients were removed from the study (four had progressive disease/disease recurrence and four had ototoxicity). Grade 3/4 toxicities included neutropenia (n = 20), thrombocytopenia (n = 14), electrolyte imbalances (n = 14), and gastrointestinal toxicity (n = 12). Twenty-four of 25 patients received hearing evaluations, and 75% had significant hearing loss. CONCLUSIONS: Amifostine did not protect against HDPEB-associated ototoxicity. (+info)
Phase I trial and pharmacokinetics of escalating doses of paclitaxel and concurrent hyperfractionated radiotherapy with or without amifostine in patients with advanced head and neck carcinoma.
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BACKGROUND: Amifostine was developed to protect normal tissues from radiation exposure. The current study was undertaken to determine whether amifostine would allow the delivery of greater numbers of weekly paclitaxel treatments with concomitant, hyperfractionated radiotherapy in patients with advanced head and neck carcinoma. METHODS: Patients received radiation therapy twice daily using 1.6-gray (Gy) fractions up to a total of 70.4 Gy over an elapsed time of 6.5 weeks. All patients received paclitaxel 60 mg/m(2) once weekly starting on Day 1. The number of doses of paclitaxel was escalated from three to a maximum of six in groups of three patients. For the patients who received amifostine, a dose of 400 mg/m(2) was given intravenously over 15 minutes on Days 1-5, 8, 29-33, and 36. Patients underwent surgery for persistent tumor after radiotherapy. The plasma pharmacokinetics of paclitaxel were characterized during treatment with the first weekly dose to determine the effect of concurrently administered amifostine. RESULTS: Thirty-six patients were evaluable for this study. In the absence of amifostine, a maximum of four doses of paclitaxel were tolerated in combination with the radiotherapy. With amifostine, up to five doses of paclitaxel could be given. Generally, the treatment resulted in Grade 2 and 3 stomatitis. Overall, 69% of patients had a complete remission, and 29% had a partial remission. Both progression-free survival and overall survival were 66% at 30 months. Amifostine had no effect on the pharmacokinetics of paclitaxel. CONCLUSIONS: The administration of amifostine allowed the authors to give an additional dose of paclitaxel to patients who were undergoing hyperfractionated radiotherapy for head and neck carcinoma. This treatment regimen resulted in a high frequency of complete remissions and an excellent progression-free survival pattern without compromising the plasma kinetics of paclitaxel. (+info)
A potential synergistic anticancer effect of paclitaxel and amifostine on endometrial cancer.
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Although paclitaxel is one of the most effective chemotherapeutic agents, its usefulness is still limited in advanced and recurrent endometrial cancer. Amifostine protection of normal tissues against the side effects of chemotherapeutic agents has been clinically proven in cancer patients; however, its application in endometrial cancer has not been fully evaluated. We have investigated the use of paclitaxel and amifostine in controlling the growth of poorly differentiated endometrial cancer cells, Hec50co, in vitro and in vivo. Our studies show that amifostine had direct anticancer effects on endometrial cancer cells in vitro by arresting the cell cycle at the G1 phase and inducing apoptosis. Amifostine also inhibited s.c. tumor growth in athymic mice. Paclitaxel IC50 value was reduced from 14 to 2 nmol/L with pretreatment of a single dose of 178 micromol/L of amifostine for 72 hours. Amifostine also synergized with paclitaxel in the arrest of the cell cycle at the G2-M phase and in the induction of apoptosis. This two-drug regimen inhibited s.c. tumor growth as well as improved mouse survival significantly more than paclitaxel alone. Amifostine also significantly improved paclitaxel-induced cytotoxic effects on peripheral blood profiles. Our studies show that amifostine has direct anticancer effects on endometrial cancer. Our data have also shown a potential anticancer synergy between amifostine and paclitaxel in vitro and in vivo, whereas amifostine maintained a protective role in peripheral blood profiles. The dual specificity of amifostine action should be further investigated. (+info)