Alteration of radiation-induced hematotoxicity by amifostine

Lymphopenia and intratumoral lymphocytic balance in the era of cancer immuno-radiotherapy

INTRODUCTION

The immune response has been recognized as a major tumor-eradication component of radiotherapy.

OBJECTIVE

This review studies, under a clinical perspective, two contrasting effects of radiotherapy, namely immunosuppression and radiovaccination.

MATERIALS AND METHODS

We critically reviewed the available clinical and experimental experience on radiotherapy-induced lymphopenia.

RESULTS

Radiation-induced tumor damage promotes radio-vaccination, enhances cytotoxic immune responses, and potentiates immunotherapy. Nevertheless, radiotherapy induces systemic and intratumoral lymphopenia. The above effects are directly related to radiotherapy fractionation and field size/location, and tumor characteristics.

DISCUSSION

Hypofractionated stereotactic and accelerated irradiation better promotes radio-vaccination and produces less severe lymphopenia. Adopting cytoprotective policies and combining lympho-stimulatory agents or agents blocking regulatory lymphocyte activity are awaited to unmask the radio-vaccination effect, enhancing the efficacy immuno-radiotherapy.

CONCLUSION

Radiation-induced lymphopenia and immunosuppression are important issues that should be considered in the design of immuno-radiotherapy clinical trials.

Reduction in radiation-induced lymphocytopenia by famotidine in patients undergoing radiotherapy for prostate cancer

BACKGROUND

Ionizing radiation causes a series of hematological alterations especially profound lymphocytopenia during and after the radiotherapy course. To investigate whether famotidine can reduce hematologic toxicity in patients treated with radiotherapy for prostate cancer.

METHODS

A total of 36 patients undergoing radiotherapy for prostate cancer were randomized to receive either placebo or famotidine tablets. Participants were pretreated with 40 mg of oral famotidine or placebo tablets twice daily, 4 and 3 hr before each radiotherapy fraction. The patients received external-beam radiotherapy up to 70 Gy. Complete blood counts with differential, platelet counts, and hemoglobin levels were obtained at baseline, biweekly during the treatment and once 4 weeks after the end of radiotherapy course. Magnitude of changes from baseline in the hematological parameters was determined and compared using Repeated Measures ANOVA.

RESULTS

Famotidine was well tolerated. A total of 112 blood samples were evaluated. A significant reduction in radiation-induced lymphocytopenia was noted in patients receiving famotidine than in patients receiving placebo (P = 0.006). No significant difference was observed between two groups for the decline in platelets, erythrocytes and leucocytes. For both groups, neutrophil, monocyte, eosinophil, and hemoglobin levels did not change significantly during the treatment.

CONCLUSIONS

Our results indicate that famotidine could result in a significant reduction in radiation-induced lymphocytopenia and may consequently increase radiotherapy efficacy as well as survival times. This radioprotective effect may be chiefly associated with its antioxidant and radical scavenging properties. Further studies are required to confirm these encouraging results.

Radiomodulatory role of Rutin and Quercetin in Swiss Albino mice exposed to the whole body gamma radiation

Context:

Radiation therapy is the prime treatment modality against various cancers. However, its use is limited due to the effects of radiation on normal tissues.

Aims:

In view of this, present study was carried out to evaluate the radioprotective potential of Rutin (RUT) and Quercetin (QRT) in Swiss Albino mice exposed to the whole body gamma radiation. To gain insight into the mechanism of action, RUT and QRT were tested for its antioxidant levels in mice.

Settings and Designs:

Optimum protective dose of RUT and QRT against radiation induced animal mortality was selected by administration of various doses of the RUT and QRT before 10 Gy gamma irradiation.

Materials and Methods:

Swiss Albino mice were used for the assessment of radiation induced sickness along with the survival analysis and anti-oxidative properties of RUT and QRT.

Statistical Analysis Used:

Survival studies were determined using the Kaplan-Meier survival curves.

Results:

The maximum survival was observed with 10 mg/kg. b. wt. and 20 mg/kg. b. wt. of RUT and QRT respectively, this dose was considered as an optimal dose for radioprotection. Treatment of mice with RUT and QRT before irradiation delayed the onset of mortality as compared with the untreated irradiated controls. The oral administration of RUT and QRT resulted in an increase in the radiation tolerance and the dose reduction factor was found to be 1.15 and 1.11 respectively. RUT and QRT pre-treatment significantly (P < 0.01) elevated levels of reduced glutathione, glutathione-S-transferase, catalase, Superoxide dismutase, and a decreased lipid peroxidation in mouse liver homogenate at 24 h after exposure to 4.5 Gy.

Conclusions:

Present findings demonstrate the potential of RUT and QRT in mitigating radiation-induced mortality, which may be attributed to the elevation in the antioxidant status, anti-lipid peroxidative potential.

Allopurinol gel mitigates radiation-induced mucositis and dermatitis

It has not been verified whether allopurinol application is beneficial in decreasing the severity of radiation-induced oral mucositis and dermatitis. Rats were divided into 4 groups and received 15 Gy irradiation on the left whisker pad. Group 1 received only irradiation. Group 2 was maintained by applying allopurinol/carrageenan-mixed gel (allopurinol gel) continuously from 2 days before to 20 days after irradiation. Group 3 had allopurinol gel applied for 20 days after radiation. Group 4 was maintained by applying carrageenan gel continuously from 2 days before to 20 days after irradiation. The intra oral mucosal and acute skin reactions were assessed daily using mucositis and skin score systems. The escape thresholds for mechanical stimulation to the left whisker pad were measured daily. In addition, the irradiated tissues at the endpoint of this study were compared with naïve tissue. Escape threshold in group 2 was significantly higher than that in group 1, and mucositis and skin scores were much improved compared with those of group 1. Concerning escape threshold, mucositis and skin scores in group 3 began to improve 10 days after irradiation. Group 4 showed severe symptoms of mucositis and dermatitis to the same extent as that observed in group 1. In the histophathological study, the tissues of group 1 showed severe inflammatory reactions, compared with those of group 2. These results suggest that allopurinol gel application can mitigate inflammation reactions associated with radiation-induced oral mucositis and dermatitis.

Carcinoma de células escamosas da hipofaringe em mulher jovem com anemia de Fanconi

A anemia de Fanconi é um raro distúrbio autossômico recessivo caracterizado por malformações congênitas, aplasia da medula óssea e instabilidade genômica, com predisposição ao desenvolvimento de neoplasias malignas, em especial as leucemias e os tumores do trato aerodigestivo alto. Em razão de características inerentes à síndrome em questão, o tratamento de tais neoplasias é particularmente difícil. Relata-se o caso de anemia de Fanconi uma jovem de 24 anos, que desenvolveu carcinoma de células escamosas da hipofaringe, na ausência de fatores de risco como o tabagismo e o alcoolismo, e faz-se uma revisão sumária da literatura a respeito do tema.

Squamous cell carcinoma of the hypopharynx in a young woman with Fanconi’s anemia

Fanconi's anemia is a rare autosomal recessive disorder characterized by congenital malformation, bone marrow failure and genomic instability, with a predisposition to develop malignancies, especially the leukemias and upper aerodigestive tract tumors. Due to inherent characteristics to this syndrome, the treatment of such neoplasms is particularly difficult. In this paper we report the case of a 24-year-old woman with Fanconi's anemia who developed a squamous cell carcinoma of the hypopharynx; she had none of the traditional risk factors, such as smoking and alcohol abuse. We also briefly review the literature about this topic.

Amifostine reduces side effects and improves complete response rate during radiotherapy: Results of a meta-analysis

PURPOSE

To evaluate the efficacy of amifostine in diminishing radiotherapy side effects and whether or not it protects the tumor.

METHODS AND MATERIALS

We performed a systematic review and meta-analysis of 14 included randomized controlled trials, comprising 1451 patients, comparing the use of radiotherapy vs. radiotherapy plus amifostine for cancer treatment.

RESULTS

The use of amifostine significantly reduced the risk of developing mucositis (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.29-0.48; p < 0.00001), esophagitis (OR, 0.38; CI, 0.26-0.54; p < 0.00001), acute xerostomia (OR, 0.24; CI, 0.15-0.36; p < 0.00001), late xerostomia (OR, 0.33; CI, 0.21-0.51; p < 0.00001), dysphagia (OR, 0.26; CI, 0.07-0.92; p = 0.04), acute pneumonitis (OR, 0.15; CI, 0.07-0.31; p < 0.00001) and cystitis (OR, 0.17; CI, 0.09-0.32; p < 0.00001). There was no difference in overall response rate between the groups. However, complete response rate was superior for patients using amifostine (OR, 1.81; CI, 1.10-2.96; p = 0.02).

CONCLUSIONS

This systematic review shows that amifostine significantly reduces the side effects of radiation therapy. The efficacy of radiotherapy was not itself affected by the use of this drug and patients receiving amifostine were able to achieve higher rates of complete response.

Vitamin E and L-carnitine, separately or in combination, in the prevention of radiation-induced oral mucositis and myelosuppression: a controlled study in a rat model

The aim of this study was to determine the effects of vitamin E (VE) and L-carnitine (LC) supplementation, separately or in combination, on radiation-induced oral mucositis and myelosuppression. Group 1 received no treatment (control). Group 2 received 15 Gray of 60Co gamma irradiation as a single dose to total cranium (IR). Group 3, 4, and 5 received irradiation plus 40 mg/kg/day VE (IR+VE) or 200 mg/kg/day LC (IR+LC) or in combination (IR+VE+LC) respectively. Clinically and histopathologically, assessments of mucosal reactions were performed by two independent experts in Radiation Oncology and Pathology, respectively. Hematologic analyses and antioxidant enzyme evaluations were also performed. Irradiation significantly increased oral mucositis, and decreased thrombocyte and White Blood Cell counts. A significant increase in malondialdehyde (MDA) levels and decrease in superoxide dismutase (SOD) and catalase (CAT) activities in plasma were found in the IR group. VE and LC administration, separately, plus irradiation significantly delayed the starting day, and reduced the severity of, oral mucositis. This administration also reduced a fall in the numbers of thrombocyte and WBC caused by irradiation, and decreased the MDA level, and increased the activity of SOD and CAT enzymes in the plasma. VE and LC, in combination, plus irradiation did not provide a superior radioprotection against radiation-induced toxicities.

Effects of radiation on the longitudinal trends of hemoglobin levels in the Japanese atomic bomb survivors

The late effects of radiation on the hematopoietic system have not been fully evaluated. We examined the long-term effects of radiation exposure on hemoglobin levels in the Japanese atomic bomb survivors over a 40-year period from 1958 to 1998. Compared to the unexposed survivors, the mean hemoglobin levels for those exposed to a bone marrow dose of 1 Gy were significantly reduced by 0.10 g/dl (95% CI: 0.04 to 0.16) or 0.67% at 40 years of age (P < 0.0001) and by 0.24 g/dl (95% CI: 0.08 to 0.40) or 1.8% at 80 years of age. Radiation effects are greater for smokers than for nonsmokers at age less than 35 years (P < 0.01), although cigarette smoking was associated with increased hemoglobin levels. Sex and birth cohort differences in radiation effects were not found after adjusting for smoking. The radiation-induced reduction in hemoglobin levels could not be explained by the presence of certain anemia-associated diseases.