LB Disease - Colonic Polyps and Cancer

Question 1

What is the association between colon polyps and colon cancer?

Answer 1

Colon cancers are believed to arise from adenomatous polyps (and ultimately the colon epithelia)

Question 2

What are the types of colon polyps?

Answer 2

Hyperplastic (non-neoplastic)

Adenomatous (tubular, tubulovillous and villous)

Question 3

What are characteristics of adenomatous polyps?

Answer 3

• Large, villous adenomas have highest malignant potential
• Progression to cancer from early adenoma takes approximately 10 years
• Almost all colon cancers arise from adenomas
• Only 1% of adenomatous polyps ever become malignant

Question 4

What are the risk factors for colon cancer?

Answer 4

• Age > 50
• Personal history of CRC or adenomatous polyps
• Family history of CRC
• Inflammatory bowel disease
• Ulcerative Colitis
• Crohn’s Disease
• Familial colon cancer syndromes

Question 5

Describe several types of Familial colon cancer syndromes.

Answer 5

1. Familial adenomatous polyposis (FAP)
   - Autosomal dominant syndrome resulting from mutation in the APC gene
   - Hundreds of adenomas in the colon
   - Nearly 100% risk of cancer (mean age of 40) if not treated
   - Patients usually require a colectomy at young age
   - Annual flex sig beginning age 10-12
2. Hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome)
   - Occurrence of CRC in at least three 1st degree relatives over at least 2 generations with at least 1 person diagnosed < age 50
   - Screening colonoscopy at age 20-25, or 10 years earlier than youngest age of diagnosis in family

Question 6

How do we stage colon cancer?

Answer 6

TMN and Dukes Criteria

Question 7

How do we treat colon cancer?

Answer 7

The rate of survival of patients with colorectal carcinoma is based on the stage of disease. Unfortunately, 45% of patients first come to medical attention with stage III or IV disease.

Surgery alone is curative for early-stage colorectal cancers.

Surgery and adjuvant chemotherapy alone are recommended for stage III colon cancer.

For patients with stage II and III rectal cancer, the combination of postoperative radiation and 5-fluorouracil (± leucovorin) has been found to significantly reduce the recurrence rate, cancer-related deaths, and overall mortality. Independent of nodal status, preoperative chemoradiotherapy followed adjuvant chemotherapy is recommended for patients with locally advanced rectal cancers.

For patients with stage IV disease, palliative surgery, chemotherapy, and radiation therapy are the mainstays of therapy

Question 8

What are latest colon cancer screening recommendations?

Answer 8

Beginning at age 50 years old, with a colonoscopy every 10 years.

UNLESS you have a family history of CRC then its a colonoscopy every 5 years beginning at age 40 years, or 10 years younger than earliest diagnosis, whichever comes first

Question 9

What are the clinical findings in a patient with colorectal cancer?

Answer 9

• Change in bowel habits, pain, bleeding, constipation

- Change in stool diameter, weight loss

Question 10

What puts you at an increased risk for colorectal cancer?

Answer 10

High fat/low fiber diet, smoking, ulcerative colitis

Question 11

How do we diagnose colorectal cancer?

Answer 11

Exam: Occult bleeding on DRE

Labs: Increased CEA, Colonoscopy with biopsy, BE: mass

Question 12

How do we treat colorectal cancer?

Answer 12

• Colectomy
• Chemotherapy: 5-FU
• Radiation therapy

Question 13

What do you see with a barium enema in a patient with colorectal cancer?

Answer 13

Apple core lesion