Colorectal cancer

Question 1

Familial adenomatous polyps

Answer 1

1. Familial adenomatous polyp
   - deleted copy of APC gene ( tumor supressor)
   - numerous polyps form on the inside of the colon
   - increased likelihood of cancer under 50

Question 2

The adenocarcinoma sequence - familial adenomatous polyp cancer

Answer 2

1. normal colon mucosa
   -> APC gene mutation -> polyp forming
2. Early adenoma - polyp
   -> KRAS ( oncogene) mutation -> bigger polyps
3. TP53 tumor supressor gene mutation
   T(P53) regulated progress of cell into G2
4. Adenocarcinoma forms

Question 3

Lynch syndrome

Answer 3

1. Heriditiary nonpolyposis colorectal cancer
   - > MMR gene which corrects DNA sequence mismatches during replication
   - > accumulation of mutations - cancer

Question 4

GIST

Answer 4

• caused by mutation of KIT protooncogene
• tumors form in intestinal cells of Cajal
• tumors can become malignant and be found in the large bowel

Question 5

types of colorectal cancer

Answer 5

1. GIST
2. Lynch syndrome
3. Familial adenomatous polyp ( cancer)

Question 6

symptoms of colorectal cancer

Answer 6

1. bleeding from back passage
2. Change in bowel habits
3. Loss of weight
4. Vomiting and fatigue

Question 7

treatment

Answer 7

1. rectal exam - feel for polyps
2. colonoscopy - check for polyps and biopsy
3. barium enema
4. remove colon