Colorectal cancer (CRC) starts as non-cancerous polyps inside the colon or rectum. Second leading cause of cancer deaths worldwide (1.9M cases, 930k deaths in 2020).
Types of Colon Cancer
• Adenocarcinoma: >90% of cases. Subtypes: Mucinous Adenocarcinoma (~55% mucin, spreads rapidly) and Signet Cell Carcinoma (rare & aggressive).
• Other Types: GI carcinoid tumors, Lymphoma, GIST (<7000 cases/yr), Sarcoma, Melanoma metastasis, Leiomyosarcoma.
Symptoms & Red Flags
Abdominal pain, bloody/black stool, bowel habit changes (constipation/diarrhea), narrow stool, excessive gas, fatigue/anemia, unexplained weight loss, and feeling of incomplete evacuation.
Numeric & TNM Staging
Numeric: Stage 0 CIS to Stage 4C (distant metastasis).
TNM System: T0-T4b (depth through mucosal/muscle/serosal layers), N0-N2b (lymph node counts), M0-M1c (peritoneal & organ spread).
Diagnostics & Surgical Interventions
Diagnostics: Stool FOBT / FIT (90% detection), Stool DNA test, Colonoscopy with polypectomy, Biopsy, CT scans.
Treatment: Colectomy surgery, Lymph node dissection, Chemotherapy, Laparoscopy, HIPEC (cytoreductive surgery + hyperthermic chemo), HAIP (hepatic artery pump for liver metastasis), Polypectomy, Radiotherapy, Targeted therapy, and Palliative care.