Colonic Polyps and Cancer
Colonic Polyps
A Colonic Polyp is simply an abnormal growth of tissue that protrudes into the inner cavity (lumen) of the large intestine (colon). They are often categorized based on their potential for becoming cancerous:
- Neoplastic Polyps (Adenomas): These growths have the potential to turn into cancer over time.
- Non-Neoplastic Polyps: These are generally harmless and include types like Hyperplastic, Juvenile, Peutz-Jeghers, and Inflammatory polyps.
Adenomas (The Risky Ones):
Adenomas are benign (non-cancerous) growths, but they are considered pre-cancerous. They come in different types (tubular and villous).
- Higher Risk: Polyps that are large (over 2 centimeters) and have a "villous" shape are more likely to transform into malignancy (cancer).
- Lower Risk: Very small polyps (less than 5 millimeters) are often called diminutive polyps and have a very low chance of becoming cancerous.
Risk Factors for Polyps:
- Inherited Susceptibility: A genetic predisposition.
- Diet: Excessive intake of fat combined with a low-fiber diet.
Symptoms and Detection:
- Silent: Most polyps cause no clinical symptoms and are discovered accidentally.
- Possible Symptoms: Abdominal pain, rectal bleeding, changes in bowel habits (diarrhea and constipation), or, rarely, colonic obstruction.
- Detection: The majority of polyps are found during a colonoscopy.
Treatment of Polyps:
- Endoscopic Removal: If an adenoma has not invaded the deeper layers of the bowel wall, it can usually be removed safely during the colonoscopy (endoscopic resection). The removed polyp must be sent for lab analysis (histopathology) to ensure it was completely removed.
- Surgical Removal: If the polyp has invaded deeper layers, surgery is necessary to remove that section of the colon.
Colon Cancer (Colorectal Cancer):
Colon cancer is a major disease that significantly contributes to illness and death worldwide. It usually develops from an adenomatous polyp over many years.
Key Risk Factors:
- Diet: A high-fat, low-fiber diet.
- Smoking.
- Genetic Syndromes: Inherited conditions (polyposis syndromes) that cause numerous polyps.
- Family History: Having a close relative with colorectal cancer.
- Chronic Inflammation: Long-term inflammatory bowel diseases like ulcerative colitis and Crohn's disease.
Symptoms Based on Location:
The way cancer presents depends on which side of the colon it grows:
- Right-Side Tumors: These often grow larger before being noticed and may cause chronic, slow bleeding (leading to anemia) and sometimes a palpable mass (a lump that can be felt).
- Left-Side Tumors: These are more likely to cause symptoms related to obstruction, such as changes in bowel habits, abdominal pain, anemia, and chronic bleeding.
Diagnosis:
- Confirmation: A colonoscopy is essential to visualize the tumor, and a biopsy is taken from the abnormal area for histopathological confirmation.
- Staging: CECT scans of the abdomen and chest are performed to check for any signs of spread (distant metastasis).
Treatment:
- Primary Treatment: Surgery is the main treatment for colon cancer.
- Advanced Disease: For patients whose cancer has spread beyond the surface of the bowel, involves lymph nodes, or has metastasized (e.g., to the liver), chemotherapy is also required.