Colorectal cancer

Question 1

presentation of colon cancer

Answer 1

varies.... can be:
asymptomatic
weakness/anemia
change in bowel habits (classic)
bloody stool

Question 2

what are the two types of polyps found in the colon and rectum

Answer 2

ademonas

hyperplastic polyps

Question 3

what type of polyp usually causes cancer

Answer 3

pre existing adenomas

hyperplastic polyps have no malignant potential

Question 4

which adenomas have greatest malignant potential

Answer 4

“advanced” adenomas…

tubular adenomas more than 1 cm

villous adenomas

adenomas with high grade dysplasia

sessile serrated polyps more than 1 cm

sessile serrated polyps with dysplasia

traditional serrated adenoma

Question 5

how long does it take for a small adenoma to develop into malignancy

Answer 5

5-10 years

therefore cancer may be prevented by adenoma removal

Question 6

what are average risk patients for colon cancer screening

Answer 6

meet none of criteria for increased risk

50-74 years old, or over 74

Question 7

what are the increased risk patients for colon cancer screening

Answer 7

personal hx of adenomas (particularly advanced or multiple)

1st degree relative age less than 60 with CRC or advanced or multiple adenomas

two or more 1st degree relatives with CRC at any age

longstanding IBD

family hx of familial FAP or HNPCC

Question 8

screening for average risk asymptomatic patients aged 50-74

Answer 8

FIT test every 1-2 years

any positive FIT followed by colonoscopy–> can reduce mortality from CRC

colonoscopy every 10 years is also acceptable screening

Question 9

screening for average risk patients over 74 years old

Answer 9

individually assess screening to balance risk and benefit

*not recommended after age 85

Question 10

screening for patients with 1st degree relative younger than 60 with CRC or advanced adenomas (or two or more 1st degree relatives with CRC at any age)

Answer 10

colonoscopy every 5 years starting at age 40 or 10 years earlier than the age of youngest affected relative at dx

use FOBT, FS and CT colonography only when patients decline colonoscopy or have incomplete colonoscopy

Question 11

screening for patients with IBD involving majority of colon for over 8 years or left colon for over 15 years

Answer 11

colonoscopy every 1-2 years with multiple biopsies to detect occult neoplasia

Question 12

what is FAP

Answer 12

rare autosomal dominant syndrome

germline mutations in adenomatous polyposis coli (APC) gene

presence of 100 or more adenomatous colorectal polyps (can be up to thousands carpeting the mucosa)

polyposis typically develops in the second or third decade of life

colorectal cancer occurs in 100% of untreated individuals by age 45 years

Question 13

FAP screening

Answer 13

geneting counseling and testing should be offered to all 1st degree relatives as soon as possible through the hereditary cancer program at BCCA

people with FAP and their first degree relatives should be followed by GI who will work with BCCA to determine ongoing care

Question 14

what is attenuated FAP (AFAP)

Answer 14

more than 10-20 adenomas but fewer than 100

older age

often right side

up to 80% risk of developing colorectal cancer at an average age of 56 years

Question 15

screening for AFAP

Answer 15

suspect in individuals with more than 10 adenomas during lifetime

refer to hereditary cancer program at BCCA

Question 16

what is HNPCC

Answer 16

aka lynch syndrome

refers to patients who fulfill amsterdam criteria for lynch syndrome

hereditary nonpolyposis colorectal cancer

Question 17

what are the amsterdam criteria

Answer 17

for lynch syndrome

1. at least 3 relatives with lynch syndrome assoc cancer (colorectal, endometrium, small bowel, ureter, renal pelvis)
2. one is 1st degree relative of the other two
3. at least two successive generations affected
4. at least one dx before age 50
5. FAP excluded in the colorectal cancer cases
6. tumours verified with path

Question 18

screening for HNPCC

Answer 18

if have family hx…colonoscopy beginning 10 years earlier than youngest age of family member dx or at age 25

colonoscopy every 2 years until age 40 then annually

refer to BCCA

Question 19

what is the grading system of colon cancer

Answer 19

TNM staging

T1–no deeper than submucosa

T2–not through bowel wall

T3–through bowel wall

T4–through wall involving the serosa or adjacent structure

N1–regional lymph node mets (1-3 nodes)

M1–distant mets (lung, liver, bones) and/or positive peritoneal cytology and/or positive non-regional lymph nodes

Question 20

what is the mainstay of curative colon cancer tx

Answer 20

surgery

removal of segment of colon or rectum and reconnect bowel if possible

Question 21

what % of patients present with each stage of colon cancer

Answer 21

stage I–12%

stage II–24.5%

stage III–32/6%

stage IV–18.6%

Question 22

what role does chemo play in colon chancer

Answer 22

for advanced or high risk tumours

after surgery

for killing cancer cells which may have spread

Question 23

what role does radiation play in rectal cancer

Answer 23

only for rectal surgery

before surgery to shrink it

to reduce risk of cancer returning after surgery

Question 24

what role does radiation play in rectal cancer

Answer 24

only for rectal surgery

before surgery to shrink it

to reduce risk of cancer returning after surgery

Question 25

where are the incisions for a right hemicolectomy

Answer 25

at the ileum and the hepatic flexure

then do an ileocolic anastamosis

Question 26

can you do a colon-to-colon anastamosis in an unprepped bowel?

Answer 26

no…needs to be prepped

Question 27

how do you decide how much bowel to take out in colon cancer surg

Answer 27

depends on the blood supply of the bowel

needs to make sure you dont end up with dead anastamosis

Question 28

how do you decide how much bowel to take out in colon cancer surg

Answer 28

depends on the blood supply of the bowel

needs to make sure you dont end up with dead anastamosis

Question 29

what is a hartman procedure

Answer 29

for obstructing sigmoid cancer

take out the sigmoid colon and do initial colostomy with rectal pouch but then anastamose in a second surgery at the colorectal and close the ostomy site