Famotidine as a radioprotector for rectal mucosa in prostate cancer patients treated with radiotherapy: phase I/II randomized placebo-controlled trial.

BACKGROUND AND PURPOSE: Acute bowel toxicity significantly affects the quality of life of patients treated with pelvic radiotherapy. This study was performed to assess whether pretreatment with famotidine can reduce acute radiation toxicities in patients undergoing radiotherapy for prostate cancer. PATIENTS AND METHODS: Between April 2012 and February 2013, 36 patients undergoing radiotherapy for prostate cancer were enrolled to receive either placebo or famotidine. The patients received external-beam radiotherapy up to 70 Gy at daily fractions of 1.8-2 Gy (5 days/week). Oral famotidine 40 mg (80 mg/day) or placebo was administered twice daily (4 and 3 h prior to each radiotherapy fraction). Bowel and bladder acute toxicities were evaluated weekly during radiotherapy and once thereafter according to RTOG grading criteria. RESULTS: Famotidine was well tolerated. No grade III or higher acute toxicities were noted in the two groups. Grade II rectal toxicity developed significantly more often in patients receiving placebo than in patients receiving famotidine (10/18 vs. 2/16, p=0.009). Moreover, no rectal bleeding occurred in the famotidine group, while 5 patients in the placebo group experienced rectal bleeding during treatment (p=0.046). The duration of rectal toxicity in the radiotherapy course was also reduced in the famotidine group (15.7 vs. 25.2 days, p=0.027). No significant difference between the two groups was observed in terms of urinary toxicity. CONCLUSION: We demonstrated for the first time that famotidine significantly reduces radiation-induced injury on rectal mucosa representing a suitable radioprotector for patients treated with radiotherapy for prostate cancer.

Radioprotective Effects of Sulfur-containing Mineral Water of Ramsar Hot Spring with High Natural Background Radiation on Mouse Bone Marrow Cells.

BACKGROUND: We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation. OBJECTIVE: The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells. METHOD: Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed). Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy). 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes. RESULTS: A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE) and decreases in polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte ratio (PCEs/PCEs+NCEs) (P < 0.001) in sulfur-containing hot spring water compared to sulfur-free hot spring mineral water. Also, apparently there was a significant difference between drinking water and sulfur-containing hot spring water in micronuclei polychromatic erythrocyte and polychromatic erythrocyte/polychromatic erythrocyte+ normochromatic erythrocyte ratio. CONCLUSION: The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.