Colorectal Cancer

Question 1

What BV supplies the first 2/3 of Colon?

Answer 1

Superior Mesenteric artery

Question 2

What BV supplies the last 1/3 of colon?

Answer 2

Inferior Mesenteric Arteral

Question 3

What are the 4 layers of the colon wall?

Answer 3

Mucosa
Submucosa
Muscularis Propria
Serosa

Question 4

What is the most lethal cancer?

Answer 4

Lung Cancer

Question 5

How common is colorectal cancer?

Answer 5

3rd most common cancer.

Question 6

Most common cancer?

Answer 6

Prostate/Breast

Question 7

2nd most common cancer?

Answer 7

Lung cancer

Question 8

What are the 4 Genetic Palyers in colon cancer?

Answer 8

APC tumor suppressor
K-RAS proto onco-gene
DCC tumor suppressor
p53 tumor suppressor

Question 9

What are the steps of the Carcinoma sequence?

Answer 9

Mucosa ==> Adenoma ==> in situ ==> Invasive Cancer

Question 10

What is the mutation inherent in FAP?

Answer 10

APC gene mutation on chromosome 5q

Question 11

What is the inheritance pattern of FAP?

Answer 11

Autosomal Dominant

Question 12

What is the treatment for FAP?

Answer 12

Total Colectomy

Question 13

What is the genetic defect in Hereditary Nonpolyposis colon cancer? (lynch syndrome)

Answer 13

Mismatch repair gene

Hundreds of polyps, accellerated progression

Question 14

Treatment for HNCC/Lynch syndrome.

Answer 14

Colectomy

Question 15

HNCC is also associated with…………………… cancer.

Answer 15

Endometrial and ovarian cancers.

Question 16

What are the symptoms of polyps?

Answer 16

Asymptomatic. May have positive Fecal Occult Blood Test when advanced.

Question 17

What is required to prepare for a colonoscopy?

Answer 17

Clean out colon

Question 18

What is difference between Flexible sigmoidoscopy and colonoscopy.

Answer 18

FS only goes to splenic flexure.

Question 19

What are rhe benefits of doing stool based studies?

Answer 19

Stool Guiac and Fecal immunochemical test can diagnose while being less invasive.

Question 20

What are the screening regimens for Colorectal cancer?

Answer 20

Colonoscopy every 10 years
or
Flex Sigmoidoscopy every 5 years 
High sensitivity FOBT every 3 years 
or
High sense FOBT every year.

Question 21

What are the screening reccomendations for colorectal cancer?

Answer 21

Avg risk? asymptomatic, no family history of cancer, no personal risk of polyps or cancer

start at 50yo
Repeat every 10 years
repeat sooner is polyps found

Question 22

What are the screening reccomendations for colorectal cancer with a Hx of Cancer?

Answer 22

start earlier, repeat more frequently

Question 23

What are the screening reccomendations for colorectal cancer with a Hx IBS(UC or CD)?

Answer 23

Colonoscopy 8-10 years after onset, 4 random biopsies every 10 years. repeat Every 1-2 years.

Question 24

What are the screening reccomendations for colorectal cancer with a Hx of Lynch syndrome?

Answer 24

Colonoscopy 20-25yo
repeat 1-2 years
endometrial surveilance annually.
Urinalysis annually

Question 25

What are the screening reccomendations for colorectal cancer with a Hx of APC/FAP mutation?

Answer 25

Colonoscopy age 10-12 repeat 1-2 years colectomy once polyps are seen. Ileorectal/ileo-anal every 1-2 years

Question 26

Diagnostic tests for Colorectal cancer?

Answer 26

``` XR Abdomen, CTbdomen/Pelvis Colonoscopy -biopsy and tattoo Proctoscopy -biopsy and measure distance from sphincters CBC/CMP CEA-serum tumor marker CT Chest/abdomen/pelvis Biopsy of Metastatic lesions US or MRI for rectal cancer ```

Question 27

Tumor Staging of Colorectal Cancer

Answer 27

``` Tis-intraepithelial T1- MM into SM T2- invades MP T3- invades PCR tissues T4a Penetrates peritoneum T4b invades adjacent organs. ```

Question 28

General staging of Colorectal cancer

Answer 28

TNM= Tumor- invasion Depth of primary tumor Node Extent of Regional LN Mets- Presence of Distant Mets

Question 29

Nodal staging of CRC

Answer 29

N0 no regional node mets N1- Mets in 1-3 regional nodes N2- Mets in 4+ regional noedes 15 nodes need to be examined

Question 30

Mets Staging of CRC

Answer 30

MO- no distant mets | M1- Distant Mets

Question 31

Definition of Colectomy

Answer 31

Resected colon with associated mesentery

Question 32

Low anterior Resection Definition

Answer 32

Rectosigmoid resection ext below peritoneal reflection w/ associated mesorectum

Question 33

Abdominal Perineal Resection definition

Answer 33

Anal Sphincters, anal opening, and associated mesorectum.

Question 34

How to decide what Treatment to use for colon cancer?

Answer 34

T1, T2, T3 = Surgical resection T3, T4 = Resections with chemo N1, N2 = resection with chemo Liver or lung mets = Resection with Chemo Mets disease = Chemo -bleeding, obstruction or perforation = Palliative resection

Question 35

How to decide what Treatment to use for colon cancer?

Answer 35

tis, T1 = Transanal excision T2 Resection T3, T4, N+ = Neoadjuvant Chemo and Resection

Question 36

What are the ongoing Sureillance guidelines after Tx of Colorectal Cancer?

Answer 36

H &P every 3-6mon x 5y CEA every 3-6mon x 5y CT C/A/P annually x5 y