Definition
Colon cancer is a malignant tumor that develops in the mucosa of the colon or rectum. It is one of the most common cancers worldwide but is often curable if diagnosed early.

Pathogenesis
Cancer development is linked to genetic mutations and environmental factors. Polyps, especially adenomatous polyps, can develop into cancer if not removed. Risk factors include age, family history, diets high in red and processed meat, low fiber intake, and inflammatory bowel diseases.

Diagnosis
Diagnosis is made via colonoscopy, allowing direct observation and biopsy. Stool tests for hemoglobin or DNA can be used for screening. Imaging techniques, such as CT or MRI, help assess cancer spread.

Treatment
Treatment depends on the cancer stage:

• Endoscopic or surgical removal: The main treatment in early stages.
• Chemotherapy: Used in advanced stages or post-surgery to reduce recurrence risk.
• Radiotherapy: Common in rectal cancer, applied before or after surgery.
• Immunotherapy: For cancers with specific genetic mutations.

Prevention
Regular screening (colonoscopy starting at age 45 or earlier for those with family history) is critical for early detection of precancerous lesions. A healthy lifestyle, a diet rich in fiber and low in processed foods, and avoiding smoking and alcohol reduce cancer risk.

Early diagnosis and appropriate treatment significantly increase survival rates.