Intestinal Helminths and Protozoan Infections in Patients With Colorectal Cancer: Prevalence and Possible Association With Cancer Pathogenesis

The study will be conducted on the basis of Research Institute of Epidemiology, Microbiology and Infectious Diseases and Research Center of Oncology, Ministry of Public Health of the Republic of Uzbekistan.

All the CRC patients from Research Center of Oncology will be examined with their written concent. Diagnosis of CRC is based on the results of clinical examination, endoscopic, histological, X-ray and laboratory data according to International Classification proposed by the American Joint Committee on Cancer (AJCC) with application TNM (T-tumor, N-nodus, M-metastases) for diagnosis. Descriptors in T (primary tumor) mean the degree of the tumor spreading in layers of the intestine; descriptors in N mean absence of metastases or the number of lymph nodes with metastases; descriptors in M shows absence or presence of remote metastases.

The control group will be a random residents of Tashkent city without any complaints from gastrointestinal tract matched by gender and age to the patients with CRC. Age of individuals under examination will be taken at the range from 17 to 90 years old.

Collection of stool samples Three stool samples for parasitological examination will be taken from both control subjects and CRC patients at 1-2 days interval. Stool samples were collected in individual containers, containing 5 ml of Turdiev's preservative provided conservation and staining of protozoa cysts and eggs of worms for a year. The Turdiev's preservative includes:80 ml of 0.2% aqueous solution of sodium nitrite, 10 ml of formaldehyde, 2 ml of glycerin, 8 ml of Lugol's solution, 250 ml of distilled water.

Collection of material for C. parvum (Cryptosporidium parvum) detection in stool samples will be carried out by preparation of fresh feces thin smears.