Colon and Rectal Cancer -Davis

Question 1

What are the symptoms of Colorectal Cancer? How does this differ between cancers in the left and right colon?

Answer 1

-Abdominal pain or discomfort, including cramps or gas
-Blood in the stool, guiac positive hemocult
-Weakness or fatigue
(right colon)
-change in bowel habits or stool’s consistency (left colon=constrictive)
-feeling that the bowel doesn’t completely empty
-weight loss

Question 2

What are 2 of the inherited genetic mutations associated with adenocarcinoma of the colon?

Answer 2

• FAP (mutations in APC gene) =1000s of polyps

- HNPCC (Lynch syndrome) ==> only a few polyps, linked to other cancers (endometrial)

Question 3

What do most cases of colorectal cancer develop from? How long does it generally take to become clinically significant?

Answer 3

polyps

takes 5 years of growth

Question 4

What shape of adenomatous polyp is more likely to progress to cancer, sessile or pedunculated?

Answer 4

sessile (flat)

Question 5

What histologic type of adenomatous polyp is most likely to be cancerous? What size?

Answer 5

Villous

(> tubular and tubulovillous)

> 2.5 cm are 5x as likely to be cancerous

Question 6

How many lymph nodes should be removed in a colectomy?

Answer 6

As many as possible bt at least 12*

Question 7

When can Local transanal resection be used to remove colon cancer?

Answer 7

T1 N0 M0 stage I rectal cancers that are relatively small and not too far from the anus

Question 8

When can transanal endoscopic microsurgery be used to remove colon cancer?

Answer 8

T1 N0 M0 stage I cancers that are higher in the rectum

Question 9

What is a Abdominoperineal (AP) resection?

Answer 9

• One incision in the abdomen, and another in the perineal area around the anus–> allows the surgeon to remove the anus and the tissues surrounding it, including the sphincter muscle
• requires a colostomy

Question 10

What is a pelvic extenteration?

Answer 10

• Remove the rectum, but also nearby organs such as the bladder, prostate (in men), or uterus (in women)
• will need a colostomy and possibly a urostomy if the bladder is removed

Question 11

How does Radiofrequency ablation (RFA) work? Ethanol Ablation?

Answer 11

• RFA uses high-energy radio waves to kill tumors

- Ethanol ablation injects concentrated alcohol directly into the tumor to kill cancer cells

Question 12

How does cryosurgery kill tumors?

Answer 12

by freezing it with a metal probe

Question 13

What artery feeds cancer cells in the liver? What feeds normal cells? What treatment can be used to address this?

Answer 13

• Hepatic A feeds cancer cells
• Portal Vein feeds healthy cells
• hepatic artery embolization

Question 14

What staging is used for colorectal cancer?

Answer 14

TNM Staging:
T (primary tumor)
N (regional lymph nodes)
M (distant metastasis)

Question 15

At what stage has colorectal has the cancer spread to other organs?

Answer 15

Stage IV (poor prognosis)

III is in lymph nodes
II is through the lining of the colon or rectum only

Question 16

What virus can cause a precursor to anal cancer?

Answer 16

Human Papillomavirus (HPV) cause condylomata as precursor lesions associated with anal cancer

Question 17

What is the dentate line? How are tumors originating distally from this staged?

Answer 17

dentate line in the superior aspect of the anus, reflecting the change from squamous epithelium to transitional epithelium

*distal to dentate line staged as skin cancer —> rarely involve lymph nodes or distant mets

Question 18

What is the primary goal of treatment for anal cancer?

Answer 18

organ preservation

-chemo and radiation