Carcinoma of the Colon

V. Mukesh Krishna

Epidemology:

International > Colorectal Cancer (CRC) is the 3rd most common cancer in men (663,000 cases, 10.0% of the total cancers) and the second in women (570,000 cases, 9.4% of the total cases) worldwide.

India >Males = 4.3/1,00,000Females = 3.4/ 1,00,000

Race > Higher Incidence in African Americans

Sex > almost equal (ratio of 1.2:1)

Age > 55-65 years

Geographic > Countries which are more industrialized like U.S., Canada, UK, Western Europe, Australia have a much higher incidence than less industrialized parts of the world like Asia, Africa, and South America.

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Etiology / Risks• Age > 60 Yrs• Diet high in red or processed meats• Ulcerative colitis or Crohn’s Disease• Have a family history of colon cancer• Other Cancers Breast, uterine, or ovarian cancer• Familial Adenomatous Polyposis (FAP).• Hereditary non-polyposis colorectal cancer (HNPCC)

syndromes• Smoking & Alcohol• Obesity• Drug effects: Recent studies have suggested that estrogen

replacement therapy and NSAID’s such as aspirin may reduce colorectal cancer risk.

How Does Colorectal Cancer Develop?

Symptoms / Presentation• Abdominal pain and tenderness in the lower abdomen• Blood in the stool / Rectal bleeding• Diarrhea, constipation, or other change in bowel habits• Narrow stools / ribbon-like stools• Weight loss with no known reason• Unexplained, persistent nausea or vomiting• Few present with – Intestinal Obstruction / Peritonitis in Emergency• Iron-deficiency anemia, • Change in bowel habits

• Right-sided lesions are more likely to bleed and cause diarrhea, while left-sided tumors are usually detected later and could present with bowel obstruction.

Sites of Colon Cancer:

Tumors on Left Side of Colon• Intestinal Obstruction• Lower Abdominal Pain ( Colicky )• Abdominal Distention• Alternating Diarrhoea & Constipation

Sigmoid Tumors

Transverse Colon Tumors• Tenesmus + Passage of Mucus & Blood

• Mistaken for Ca Stomach – Position , Anemia + Lassitude Caecum & Ascending Colon Tumors• Sever Anemia• Mass in Rt. Iliac Fossa

Examination & Investigations• Digital rectal exam• Fecal occult blood test (FOBT)• Sigmoidoscopy ( Flexible )• Colonoscopy• Radiology

– Double Contrast Barium Enema – USG ( Liver Metastases )– Spiral CT ( Elderly )

• Future Techniques– Stool DNA Testing– Capsule Endoscopy– Virtual Colonoscopy

( CT Colonography )

Double-contrast Barium Enema

Differential Diagnoses

• Arteriovenous malformation (AVM)• Carcinoid/Neuroendocrine Tumors and Rare Tumors of

GI Tract• Crohn’s Disease• Diverticulosis, Small Intestinal• Gastrointestinal Lymphoma• Ileus• Ischemic bowel• Small Intestinal Carcinomas• Ulcerative Colitis

Staging :DukesTNMJass

Treatment :1) Surgical

Ca Ceacum > Rt. Hemicolectomy Hepatic Flexure

Pelvic Colon

2) Palliative Chemo ( In Advanced Stages )

• TS-inhibitors– Raltitrexed– Multitargeted Antifolat

• Oral 5-FU prodrugs– Capecitabine– UFT (Ftorafur + Uracil)– S-1– Emitefur

• New 5-FU modulators– 5-Ethyniluracil– Trimetrexate

• Other new compounds– Irinotecan– Oxaliplatin

Others :

• Bevacizumab (Avastin) anti-angiogenesis drug ( humanized monoclonal antibody to (VEGF)

• EGFR - Targeted monoclonal antibodies.• Cetuximab (Erbitux)• Panitumumab (Vectibix)

3) Radiotherapy

• ( Stage III ) - Used in combination with chemotherapy

• ( Stage IV + Liver Spread ) – • Ablation• Delivering chemotherapy or radiation directly into the liver• Cryotherapy• Combined with Surgery

Prevention :

A ) Screening : ( Reduces Mortality Risk Upto 15% )Testing options for the early detection of colorectal cancer and adenomatous polyps for asymptomatic adults aged 50 > years

• Tests that detect adenomatous polyps and cancer• Flexible sigmoidoscopy every 5 years, or• Colonoscopy every 10 years, or• Double-contrast barium enema every 5 years, or• computed tomographic colonography every 5 years• Colonoscopy in every 10 Years ( High Risk Individuals )

• Tests that primarily detect cancer• Annual guaiac-based fecal occult blood test with high test

sensitivity for cancer, or• Annual fecal immunochemical test with high test sensitivity for

cancer, or• Stool DNA test with high sensitivity for cancer, interval uncertain

B ) Lifestyle Modification & Others• Low-fat and high-fiber diets • Avoid diet high in red or processed meats, or meats cooked at

high temperatures• Eat a variety of fruits and vegetables every day.• Engage in physical activity every day.• NSAIDs• Quit Smoking & Alcohol

THANK YOU