Clinical Aspects of Colorectal Carcinoma

Question 1

Other than a change in bowel movements, blood in stool, pain, cramps, and tenesmus, what other complications can arise from left sided colorectal carcinoma?

Answer 1

Obstruction, perforation, fistula -> cancer can spread through bowel wall into another organ like bladder or vagina

Question 2

What is the best way to diagnose colorectal carcinoma? What is suboptimal?

Answer 2

Colonoscopy with biopsy

-> flexible sigmoidoscopy only evaluates left colon and would miss right-sided lesions

Question 3

What would Lower GI series show on left-sided colorectal carcinoma?

Answer 3

Also known as barium enema X-ray: Would show apple-core lesion of black within the otherwise white colon

Question 4

What are the options for diagnosis of CRC if a patient doesn’t want to do enema or colonoscopy?

Answer 4

CT colonography

-> if test is positive, patient will need a colonoscopy anyway for definitive diagnosis

Question 5

Do hyperplastic polyps on colonic sigmoidoscopy warrant colonoscopy? What size of lesion of adenomatous polyp is considered to have malignant potential?

Answer 5

Hyperplastic -> NO

Adenomatous -> >1cm have malignant potential (advanced)
Finding one of these of any size warrants full colonoscopy

Question 6

Are symptomatic patients screened for cancer?

Answer 6

No, they undergo a diagnostic workup

Screening is for asymptomatic patients

Question 7

What is surveillance?

Answer 7

Screening for colon cancer in patients with a history of cancer or pre-malignant lesions

Question 8

When should average risk patients begin screening by colonoscopy?

Answer 8

Age 50, or age 45 if African American

Question 9

What are the alternatives to screening by colonoscopy every 10 years?

Answer 9

1. Yearly fecal occult blood test (FOBT)
2. Yearly fecal immunochemical testing (FIT) - more sensitive
3. Flexible sigmoidoscopy every 5 years
4. CT colonography every 5 years

Question 10

What would be the flexible sigmoidoscopy and CT colonography findings which would prompt colonoscopy?

Answer 10

Flexible sigmoidoscopy - cannot be done if FOBT+. Also, if adenoma is found.

CT colonography - polyp >6mm is found

Question 11

When should you have colonoscopies starting before age 50 (assuming no inherited syndromes)?

Answer 11

First degree relative who has colon cancer should start screening at age 40 or 10 years before youngest relative at their CRC diagnosis

Question 12

When should colonoscopy done if you had a history of CRC?

Answer 12

If colonoscopy was incomplete prior to resection - 6 months, otherwise 3 years, then every 5 years

Question 13

What is the colonscopy protocol for IBD?

Answer 13

Colonoscopy every 1-2 years beginning 8-10 years after diagnosis of pancolitis or subtotal colitis

Take 4 biopsies every 10 cm
-> colectomy for dysplasia

Question 14

When can genetic testing for FAP be done now? What is the screening protocol?

Answer 14

Age 10-12

Generally, screening of first degree relatives should be done annually until age 35-40. If there is polyposis -> colectomy

Question 15

What drugs have been shown to impede progression of the APC sequence and why?

Answer 15

COX-2 inhibitors - i.e. aspirin, sulindac

COX-2 overexpression has been linked to colorectal carcinoma (inflammation -> more mutations)

Question 16

What is the surveillance for Lynch syndrome?

Answer 16

Colonoscopy every 1-2 years beginning at age 20-25 or 10 years before the youngest case of CRC identified in family

Annual after age 40-45

Annual screening for endometrial and ovarian cancer beginning at age 25-35

Question 17

What is a common obstructive complication of Peutz-Jeghers Syndrome?

Answer 17

Small Bowel intussusception

-> hamartomatous masses are used as a nidus for too much peristalsis, pushing them into the later sections of bowel

Question 18

What are the extra-colonic cancers which are at increased risk in PJS?

Answer 18

Breast and GI (i.e. pancreatic) as well as pelvic (testicular, ovarian, cervical)

Question 19

What is the surveillance of PJS?

Answer 19

EGD beginning at age 10 for intestinal hamartomas

Colonoscopies every 3 years beginning at age 25 looking for CRC

Breast surveillance starting at age 25

Abdominal / pelvic exams with PAPs starting at age 25

Question 20

What is neo-adjuvant / adjuvant therapy for CRC and when is it used?

Answer 20

Neoadjuvant - surgery with PRE-operative chemo
-> Stage II (no lymph node involvement)

Adjuvant - surgery with POST-operative chemo -> used when lymph node involvement is seen (Stage III)

Question 21

When can surgery for liver metastases be done?

Answer 21

When the metastases are isolated based on CT scan -> only 1 or 2

Question 22

What is done for CRC in advanced disease?

Answer 22

Advanced metastasis - chemotherapy

Very advanced with obstruction - stent palliation if entirely inoperable

Question 23

How can CRC be prevented via lifestyle modifications and supplementations?

Answer 23

Diet: decrease red meat / fat, increase fiber

Avoid obesity and smoking

Use aspirin and COX-2 selective NSAIDs

Calcium, antioxidants, folate