Clinical Aspects of Colorectal Carcinoma Flashcards
Other than a change in bowel movements, blood in stool, pain, cramps, and tenesmus, what other complications can arise from left sided colorectal carcinoma?
Obstruction, perforation, fistula -> cancer can spread through bowel wall into another organ like bladder or vagina
What is the best way to diagnose colorectal carcinoma? What is suboptimal?
Colonoscopy with biopsy
-> flexible sigmoidoscopy only evaluates left colon and would miss right-sided lesions
What would Lower GI series show on left-sided colorectal carcinoma?
Also known as barium enema X-ray: Would show apple-core lesion of black within the otherwise white colon
What are the options for diagnosis of CRC if a patient doesn’t want to do enema or colonoscopy?
CT colonography
-> if test is positive, patient will need a colonoscopy anyway for definitive diagnosis
Do hyperplastic polyps on colonic sigmoidoscopy warrant colonoscopy? What size of lesion of adenomatous polyp is considered to have malignant potential?
Hyperplastic -> NO
Adenomatous -> >1cm have malignant potential (advanced)
Finding one of these of any size warrants full colonoscopy
Are symptomatic patients screened for cancer?
No, they undergo a diagnostic workup
Screening is for asymptomatic patients
What is surveillance?
Screening for colon cancer in patients with a history of cancer or pre-malignant lesions
When should average risk patients begin screening by colonoscopy?
Age 50, or age 45 if African American
What are the alternatives to screening by colonoscopy every 10 years?
- Yearly fecal occult blood test (FOBT)
- Yearly fecal immunochemical testing (FIT) - more sensitive
- Flexible sigmoidoscopy every 5 years
- CT colonography every 5 years
What would be the flexible sigmoidoscopy and CT colonography findings which would prompt colonoscopy?
Flexible sigmoidoscopy - cannot be done if FOBT+. Also, if adenoma is found.
CT colonography - polyp >6mm is found
When should you have colonoscopies starting before age 50 (assuming no inherited syndromes)?
First degree relative who has colon cancer should start screening at age 40 or 10 years before youngest relative at their CRC diagnosis
When should colonoscopy done if you had a history of CRC?
If colonoscopy was incomplete prior to resection - 6 months, otherwise 3 years, then every 5 years
What is the colonscopy protocol for IBD?
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
When can genetic testing for FAP be done now? What is the screening protocol?
Age 10-12
Generally, screening of first degree relatives should be done annually until age 35-40. If there is polyposis -> colectomy
What drugs have been shown to impede progression of the APC sequence and why?
COX-2 inhibitors - i.e. aspirin, sulindac
COX-2 overexpression has been linked to colorectal carcinoma (inflammation -> more mutations)
What is the surveillance for Lynch syndrome?
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
What is a common obstructive complication of Peutz-Jeghers Syndrome?
Small Bowel intussusception
-> hamartomatous masses are used as a nidus for too much peristalsis, pushing them into the later sections of bowel
What are the extra-colonic cancers which are at increased risk in PJS?
Breast and GI (i.e. pancreatic) as well as pelvic (testicular, ovarian, cervical)
What is the surveillance of PJS?
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
What is neo-adjuvant / adjuvant therapy for CRC and when is it used?
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)
When can surgery for liver metastases be done?
When the metastases are isolated based on CT scan -> only 1 or 2
What is done for CRC in advanced disease?
Advanced metastasis - chemotherapy
Very advanced with obstruction - stent palliation if entirely inoperable
How can CRC be prevented via lifestyle modifications and supplementations?
Diet: decrease red meat / fat, increase fiber
Avoid obesity and smoking
Use aspirin and COX-2 selective NSAIDs
Calcium, antioxidants, folate
