Colon Cancer Flashcards Preview

Gastrointestinal > Colon Cancer > Flashcards

Flashcards in Colon Cancer Deck (68):
1

What is the flexure of the right colon?

Hepatic flexure

2

What is the flexure on the left side of the colon?

Splenic flexure

3

What are the folds that help hold stool in the rectum?

Transverse rectal folds

4

What are the branches of the SMA?

ileocolic
Right colic
Middle colic

5

What are the branches of the IMA?

Left colic
Sigmoidal
Rectal

6

What is the blood supply to the superior part of the rectum? What is this a branch of?

Superior hemorrhoidal

Branch of the IMA

7

What is the blood supply to the inferior part o the rectum? What are these branches of?

Middle rectal
Inferior rectal

Both branches of the internal iliac

8

What are the four histological layers of the colon?

Mucosa
Submucosa
Muscularis propria
Serosa

9

What are the three big CAs? (as far as incidence, in order)

Prostate/breast
Lung
Colon

10

What are the risk factors for the development of colon CA?

IBDs
Obesity

11

What diet is a risk factor for colon cancer?

Red meats and animal fats

12

What are the three protective factors for colon cancer?

Hormone replacement therapy
NSAID use
Fiberous diet

13

What are the four DNA proteins that are implicated in colon CA?

APC
KRAS
DCC
p53

14

What is the order of genetic mutations of the adenoma-carcinoma sequence?

APC
KRAS
DCC
p53

15

How long does it take for the adenoma-carcinoma sequence to develop?

10 years

16

What changes with APC gene mutation?

Dysplastic aberrant crypt foci

17

What changes with KRAS mutation?

Intermediate adenoma

18

What happens with DCC mutation?

Late adenoma

19

What happens with -53 mutation?

Carcinoma development

20

Most etiologies of colon cancer are from what?

sporadic (80%)

21

What is the genetic mutation in familial adenomatous polyposis? How does this present? What is the treatment for this?

APC gene mutation on chromosome 5q

Tons o' polyps early on
Total colectomy

22

What is Hereditary Non-Polyposis Colon Cancer (HNPCC/lynch syndrome)? Presentation? Treatment?

Mismatch defect in repairing chromosomes

Hundreds of polyps
Total colectomy

23

What are the ssx of early poylps? Late?

asymptomatic early

Maybe positive fecal occult blood test for late

24

What are the three major screening modalities for colon CA screening?

Colonoscopy
Flexible sigmoidoscopy
FOBT

25

What are the two radiological modalities of screening for colon cancer?

Double contract Ba enema

CT colonography

26

What is the gold standard for colon CA screening?

Colonoscopy

27

What is flexible sigmoidoscopy? Advantages/disadvantages?

similar to colonoscopy, but only reaches the splenic flexure

Do not have to prep as much and less sedation

Cannot excise polyps***

28

What does stool guaiac blood test assess for?

Peroxidase activity

29

What does the fecal immunochemical test assess for?

Antibody test

30

What is a double contrast Ba enema?

Rectal air and contrast instilled and visualize the colon wall

Requires cathartic bowel prep

31

What is a CT colonography?

Rectal air and contrast instilled, as well as cathartic bowel prep

32

How often do you repeat colonoscopies? Flexible sigmoidoscopies? FOBTs?

Colonoscopy = 10 yrs
Flexible sigmoid = 5 yrs + FOBT 3 years
FOBT = every 1-3 years

33

What are the three characteristics of "average risk" for colon CA?

Asymptomatic
No family h/o CA
No personal h/o polyps/CA

34

What are the three characteristics of the higher risk pt that should start colonoscopies at age 40, and repeat every 5 years?

-First degree relative less than 60 yo
-2x first degree relatives any age
-Second degree relative age less than 50

35

What should colonoscopies begin with IBDs? What is different about these (frequency, what is done)?

8-10 years, 1-2 years
must collect 4x random biopsies

36

When should colonoscopies begin with lynch syndrome? Frequency?

20-25, repeat 1-2 years

37

When should colonoscopies being in pts with FAP/APC mutation? Frequency? When should a total colectomy be performed?

10-12 yo
Repeat 1-2 years

Colectomy as soon as polyps are seen

38

What are the ssx of colon CA (if any)? (5)

-Vague abdominal pain
-Change in bowel habits
-Bleeding
-Obstruction
-Perforation

39

Where do colon CAs usually metastasize to?

inguinal lymph nodes

40

What is the dye that is used to tattooing the site of a polypectomy?

Methylene blue

41

During a proctoscopy, from where do you measure from to the polyp?

Sphincter

42

What is the serum marker for colon CA? What is this used for?

CEA

Used as a surveillance marker

43

What is the purpose of doing a CT/PET scan after biopsy of a malignant polyp?

Check for mets

44

T1 tumor = ?

Muscularis mucosa into submucosa

45

T2 tumor = ?

INvades muscularis propria

46

T3 tumor = ?

INvades pericolorectal tissues

47

T4a tumor = ?

Penetrates peritoneum

48

T4b tumor = ?

Invades adjacent organs

49

Tis tumor = ?

Intraepithelial

50

N0 = ?

No regional node mets

51

N1 = ?

1-3 mets in nodes

52

N2 = ?

4+ nodes

53

How many nodes need to be examined for adequate node staging?

15 nodes

54

Where are nodes collected from for staging colon CA?

Visceral mesentery

55

What are the M stages?

M0 = no mets
M1 = distant mets

56

What are the margins needed for colon resections? How is this determined?

5 cm

Based on blood supply--All bowel supplied by the resected vessel must be removed

57

What is involved in a colectomy?

Resected colon with associated mesentery

58

What is involved in a low anterior resection (LAR)?

Rectosigmoid resection extending below the peritoneal reflection

59

What is involved in an abdominal perineal resection?

Rectosigmoid resection including anal sphincters, anal opening, and associated mesorectum

60

What is the treatment for T1, T2, or T3 colon cancers?

Surgical resection is enough

61

What is the treatment for T3, T4 colon cancers?

Surgical resection with chemo

62

N1 or N2 colon cancers treatment = ?

Surgical resection + chemo

63

What is done with mets from colon CA to the live or other nearby organs? Why is this different than other CAs?

Resect them--provide better outcome. Others "cat's out of the bag"

64

What are the three palliative resection cases for colon CA?

Bleeding
Perforation
Obstruction

65

What is the treatment for Tis or T1 rectal CA?

Transanal excision

66

What is the treatment for T2 rectal CA?

Surgical resection

67

What is the treatment for T3, T4, or N+ rectal cancer?

Neoadjuvant chemoradiation + surgical resection

68

What are the three surveillance measures for rectal CA? Frequency?

H&P ever 3-6 yrs
CEA " "
Ct x5 years