Six million cancer patients worldwide receive radiotherapy, either alone or in combination with other cancer treatments annually. The purpose of this study was to investigate, at the structural and molecular levels, the protective effect of N-acetylcysteine (NAC), a powerful antioxidant, against radiotherapy-induced damage on the intestinal system. Three study groups were constituted: control (group 1: no radiotherapy), radiotherapy (RT; group 2), and RT + NAC (group 3). The NAC group received 300 mg/kg NAC orally for five days before irradiation. At the end of the 5th day, 6 Gy was irradiated once, and 300 mg/kg NAC was administered orally for two days following irradiation. NAC drug administration was maintained for a total of seven days. At the end of the study, the rats were euthanized by the administration of anesthetic agents and sacrificed. The malondialdehyde (MDA) levels and caspase-3 expression increased and glutathione (GSH) levels decreased in RT rats compared to the control group ( p < 0.05). NAC reduced MDA levels, and caspase-3 expression, and increased GSH levels in the small intestine caused by RT ( p < 0.05). Therefore, NAC may be useful in the prevention of gastrointestinal syndrome in patients undergoing radiotherapy in the treatment of malignancy. Impact statement: Some six million cancer patients currently receive radiotherapy. Radiotherapy eliminates cancer cells by accelerating their death. However, radiotherapy is not selective, and it therefore harms healthy tissues around cancerous tissue. The latest studies have shown that the irradiation of biological materials causes a rapid increase in reactive oxygen species (ROS) in the tissue as a result of exposure of the target molecule to direct and indirect ionization. N-acetylcysteine (NAC) is an antioxidant that permits the elimination of free oxygen radicals and that contributes to glutathione synthesis. Our study, therefore, examined the effects of radiation resulting from radiotherapy on the small intestine at the molecular level, and prospectively considered the potential protective characteristics of NAC against gastrointestinal syndrome resulting from radiotherapy.

Primary mucinous cystadenocarcinoma (MCA) of the breast was first described by Koenig and Tavassoli in 1998. To our knowledge, only 9 cases of MCA of the breast have been reported. The optimal treatment of MCA could not be defined yet. This article aims to increase the knowledge about this rare variant of breast cancer and to review the literature.

Therapeutic radiation of the pelvic region has been shown to cause damage to testicular germ cells. In this study we aimed to evaluate the effects of a low therapeutic dose of 1 Gy on the induction of cellular and histological damage in early-stage testicular germ cells and the impact of this radiation on offspring sex ratio. Unirradiated and irradiated male rats were mated with unirradiated female rats. Female rats were followed and the sex of the offspring was determined. The male rats were sacrificed at the end of the second week, and the testicular germ cells were subjected to genetic analysis along with cytological and histopathological examination. Sperm DNA was amplified with primers specific to testis-specific Y-linked protein, rat actin beta and testis-specific X-linked genes. The resulting products were separated by capillary electrophoresis. Histopathological changes were investigated by light microscopy along with the TUNEL assay and immunohistochemical staining for caspase-3. There was no significant difference between the two groups for sex ratio and size of offspring. The number of sperm cells bearing X or Y chromosomes’ did not differ significantly between these two groups. However, a 1 Gy dose of radiation caused significant cytopathological and histopathological changes in the testicular tissue. In the irradiated group, edematous regions were evident. The number of caspase-3 positive cells in the germinal epithelium of the seminiferous tubules was also significantly higher in the irradiated group. Our results showed that low-dose radiation induced apoptosis and caused significant cyto- and histopathological changes in the testicular tissue. Further research is required to fully elucidate their contribution to apoptosis and if low-dose radiation may potentially lead to long-term effects in the offspring. These results may also lead us to develop a new technique using the caspase-3 staining to monitor the susceptibility to low dose radiation.