Investigation The relationship between chemotherapy and intestinal parasitic infections in cancer patients undergoing chemotherapy

Cancer or neoplasia is recognized as abnormal,uncontrolled growth of cells. New cases of cancer reported everyday. Development of medical science led to diagnostic and treatment methods for cancer. Many drugs are used in cancer chemotherapy and can treat a wide range of cancers. These drugs work in different ways and can lead to deficiency of immune cells and humoral responses. So it is expected that people treating with these drugs show higher rates of parasitic infections. This study was done to compare intestinal parasitic infections in cancer patients undergoing chemotherapy with healthy ones and with cancer patients that were not undergoing chemotherapy. In this case-control study three groups of people were selected. First group were 250 cancer patients undergoing chemotherapy for at least 1 month. Second group were 250 healthy people with immunocompetency. Third group were 100 cancer patients not that undergoing chemotherapy and radiotherapy. We take a stool specimen from each person. Specimens examined by direct (for diarrheal ones) and formalin-ether (for all). In order to investigate the presence of Cryptosporidium parvum, we take a thin smear from each specimen and stained it by Zeil Nelson method. Frequency of intestinal parasitic infections in first, second and third group were 24.8%, 33.6% and 28%; respectively; but differences were not statistically significant (P=0.09%). In another investigation of intestinal parasites in three groups, infection rate of E.hartmani in second group and G.lamblia in first group was significantly higher. Infection rates of other parasites were not significantly different. Overally in three groups, most frequent parasites were B.hominis 12.8%, E.coli 11.7% and G.lamblia 4.3%,Cryptosporidium infection was not seen. Despite our hypothesis, prevalence of intestinal parasitic infections in three groups were not significantly different.Drugs used in cancer chemotherapy may have suppressive effects on parasites or kill them. In another hand, cancer patients despite their depressed immunity may show parasitic infection less than expectedbecause of less exposure to parasites due to special medical care.