Discussion
tumor, micronucleus, lymphocytopenia, thrombocytopenia, micronuclei, esophageal cancers, spermatogenesis, gastric cardia, prostate cancer, radiation-induced micronucleus
ESOPHAGEAL CANCER, TUMOR, ASPERMATOGENESIS, LYMPHOCYTOPENIA, THROMBOCYTOPENIA, DNA DAMAGE, CHROMOSOMAL ABNORMALITIES, PROSTATE CANCER, COMPLICATIONS
In the current study we assessed the effectiveness of oral famotidine as a redioprotective agent in reducing hematological complications of radiotherapy among a population of patients with gastric cardia and esophageal cancers. Our findings revealed that there was a significant reduction in thrombocytopenia in the famotidine group compared to placebo group. Moreover, the lymphocyte and platelet counts were also significantly different between famotidine and placebo groups after four weeks.In a study conducted by Razzaghdoust et al., the effect of famotidine (80 mg/day) as a radioprotective agent on rectal mucosa was evaluated in a group of prostate cancer patients treated with radiotherapy [Consistent with the results of our study, it was previously shown that among a population of prostate cancer patients undergoing radiation therapy, famotidine had a significant impact on reducing lymphocytopenia caused by radiation therapy [Also in murine models, the significant role of famotidine as a radioprotector has been observed [In another murine study, radioprotective effect of vitamin C and famotidine has been indicated, as they could significantly decrease cytotoxic effect of radiation on spermatogenesis in mice by probable mechanism of radical scavenging [With regard to the reduction in the number of hematological cells as a result of irradiation therapy, apoptosis has been revealed to be the main culprit. Being a strong scavenger of In another study antioxidation and immunomodulation have been proposed as influential mechanisms of cimetidine radioprotective effects [One of the consequences of DNA damage and repair is micronucleus formation. The number of micronucleated cells represents the cytogenetic damage caused by X-irradiation. Cimetidine was found to have a dose-dependent protective significant effect against radiation-induced micronucleus formation in human peripheral blood lymphocytes [In an experimental study to assess a combination of melatonin and famotidine as radioprotectors, Samei et al. has concluded that the radioprotective effect of combined famotidine and melatonin was the same as famotidine alone. However, famotidine has been shown to be a good radioprotective agent for normal tissue, its accretion in tumor tissues may cause a reduction in the efficacy of radiotherapy. What’s more, the results of the 2,2-diphenylpicrylhydrazyl (DPPH) assay, has demonstrated that famotidine did not have any antioxidant capacity and the 20 µg/ml and 40 µg/ml concentrations did not differ significantly. Even so, the 80 µg/ml dose of famotidine was significantly different from other doses [A dose of 5 mg/kg for famotidine was suggested to be significantly effective before 4 Gy irradiation, resulting in approximately 50% reduction in DNA damage in vivo in mouse leukocytes [It has been shown in another study that with regard to radioprotective role, famotidine alone can be as effective as it is in combination with other drugs [A DRF of 1.5–2 has been previously reported for cimetidine, ranitidine and famotidine. All three drugs were revealed to significantly decrease the frequency of radiation-induced micronuclei and chromosomal abnormalities at different doses. However, famotidine was shown to be significantly more effective compared to either cimetidine or ranitidine [