BOWEL OBSTRUCTION CAUSED BY COLORECTAL CANCER

Abstract

Colorectal cancer (CRC) ranks third among oncological diseases worldwide, with approximately 1.9 million new cases in 2020. Intestinal obstruction, occurring in 10–20% of CRC patients, is one of the most severe complications, often presenting as the initial manifestation of the disease. This thesis analyzes the epidemiology, pathogenesis, clinical features, and current challenges in the diagnosis and treatment of this complication. Obstruction, predominantly in the left colon (80% of cases), is caused by mechanical luminal narrowing due to tumors, metastases, adhesions, or fibrosis, leading to fluid accumulation, tissue ischemia, and, in severe cases, necrosis. Emergency surgeries are associated with high mortality rates (20–30%), particularly among elderly patients (median age 70 years) with advanced stages (T3/T4) and comorbidities. In Ukraine, especially in the southeastern regions, the high incidence of CRC is linked to carcinogenic environmental pollution, with a mortality-to-incidence ratio of 53.4–76%. Key challenges include nonspecific symptoms (pain, nausea, constipation), risk of complications (perforation, peritonitis), and limited options for radical treatment in advanced stages. Five-year survival rates for patients with obstruction are 30–40%, compared to 60–70% for those without. The thesis emphasizes the critical role of screening (colonoscopy, fecal tests), prevention, and early diagnosis in reducing mortality and improving quality of life, particularly in high-risk oncological regions.