Kolorektales

Kolorektales refers to colorectal cancer, a malignant tumor that originates in the colon or rectum. It is among the most common cancers worldwide and a leading cause of cancer-related death. Most colorectal cancers arise from adenomatous polyps through the adenoma-carcinoma sequence, but they can also develop via other pathways, including microsatellite instability.

Risk factors include age, family history and inherited syndromes (such as Lynch syndrome and familial adenomatous polyposis), and inflammatory bowel disease. Lifestyle factors such as high red and processed meat intake, obesity, physical inactivity, smoking, and heavy alcohol use also contribute to risk.

Screening methods are used to detect cancer at earlier, more curable stages. Colonoscopy is the preferred test in many guidelines, but sigmoidoscopy, stool-based tests (fecal immunochemical test or guaiac-based tests), and CT colonography are also available options. Regular screening reduces mortality by identifying precancerous polyps and early-stage cancers.

Diagnosis typically involves colonoscopy with biopsy and histopathological assessment. Staging uses the TNM system and imaging studies to determine the extent of spread, which guides treatment decisions.

Treatment depends on the stage and may involve surgical resection of the tumor with removal of regional lymph nodes. Rectal cancer often requires neoadjuvant chemoradiation. In advanced disease, systemic therapies such as chemotherapy, targeted therapy, and immunotherapy are used; choices depend on tumor characteristics, including genetic and molecular markers.

Prognosis varies with stage at diagnosis. Early detection through screening improves survival. Preventive measures include lifestyle modifications, such as healthy diet, regular exercise, maintaining a healthy weight, avoiding tobacco, and limiting alcohol.