Colorectal

Question 1

How is the colon divided?

Answer 1

The colon is divided into 8 regions: Cecum, Ascending colon, Descending colon, Splenic flexure, Hepatic flexure, Transverse colon, Sigmoid colon, and Rectum.

Question 2

What adjacent structures of the pelvis can colorectal cancer invade?

Answer 2

Colorectal cancer can invade adjacent structures of the pelvis such as the prostate, bladder, vagina, and sacrum.

Question 3

What are the major blood vessels associated with the colon?

Answer 3

Major blood vessels include the Hepatic portal vein, Aorta, Inferior vena cava, Superior mesenteric artery, and Inferior mesenteric artery and vein.

Question 4

What is the function of the taeniae coli?

Answer 4

Taeniae coli are bands of muscle that help in the movement of the colon.

Question 5

What are haustra?

Answer 5

Haustra are pouches formed by the contraction of the taeniae coli in the colon.

Question 6

What is the role of the external anal sphincter muscle?

Answer 6

The external anal sphincter muscle controls the expulsion of feces.

Question 7

What are the three main divisions of the large intestine?

Answer 7

The three main divisions of the large intestine are the cecum, colon, and rectum.

Question 8

What attaches to the cecum?

Answer 8

The slender vermiform appendix attaches to the posteromedial surface of the colon.

Question 9

What is the longest portion of the large intestine?

Answer 9

The colon is the longest portion of the large intestine and can be subdivided into four portions.

Question 10

What are the four portions of the colon?

Answer 10

The four portions of the colon are ascending, transverse, descending, and sigmoid.

Question 11

What are the four main layers of the bowel?

Answer 11

The four main layers of the bowel are: Mucosa, Submucosa, Muscularis propria, and Serosa.

Question 12

Where does colorectal cancer start?

Answer 12

Colorectal cancer starts in the innermost layer, which is the mucosa.

Question 13

What layers does colorectal cancer grow through?

Answer 13

Colorectal cancer can grow outward through some or all of the other layers.

Question 14

What are the four main layers of the bowel?

Answer 14

The four main layers of the bowel are: Mucosa, Submucosa, Muscularis propria, and Serosa.

Question 15

Where does colorectal cancer start?

Answer 15

Colorectal cancer starts in the innermost layer, which is the mucosa.

Question 16

What is the rank of colorectal cancer in terms of commonality?

Answer 16

3rd most common cancer in both men and women

Question 17

Is colorectal cancer more common in men or women?

Answer 17

More common in men

Question 18

What percentage of cases of colorectal cancer occur in people older than 55 years of age?

Answer 18

90% of cases occur in people older than 55 years of age

Question 19

What is the rank of colorectal cancer as a cause of cancer death in the USA?

Answer 19

2nd leading cause of cancer death in the USA

Question 20

What dietary factors contribute to colorectal cancer?

Answer 20

A diet high in animal fat and low in fiber is largely attributed to colorectal cancer.

Question 21

What lifestyle factors are associated with colorectal cancer?

Answer 21

Obesity, smoking, excessive alcohol consumption, and minimal physical activity.

Question 22

What chronic condition is a risk factor for colorectal cancer?

Answer 22

Chronic ulcerative colitis.

Question 23

What genetic conditions increase the risk of colorectal cancer?

Answer 23

Genetic familial adenomatous polyposis, Gardner syndrome, and Lynch syndrome.

Question 24

What is a sign of colorectal cancer related to bowel movements?

Answer 24

Change in bowel habits

Question 25

What is hematochezia?

Answer 25

Hematochezia refers to the passage of fresh blood through the anus.

Question 26

What symptom may indicate colorectal cancer involving stool consistency?

Answer 26

Diarrhea

Question 27

What is a common sign of colorectal cancer involving blood?

Answer 27

Rectal bleeding

Question 28

What does bright red blood in the toilet or stools indicate?

Answer 28

Bright red blood in toilet or stools can be a sign of colorectal cancer.

Question 29

What is a characteristic of stools that may suggest colorectal cancer?

Answer 29

Small caliber stools

Question 30

How does lymphatic spread occur in colorectal cancer?

Answer 30

Lymphatic spread is orderly, with the initial nodes involved for rectal cancer being the perirectal nodes.

Question 31

Which organs are commonly affected by hematogenous spread of colorectal cancer?

Answer 31

Commonly affected organs include the liver, lung, bone, ovaries, and adrenal glands.

Question 32

Which organ is the most common site for hematogenous spread of colorectal cancer?

Answer 32

The liver is the most common site for hematogenous spread.

Question 33

What is peritoneal seeding?

Answer 33

Peritoneal seeding refers to the spread of lesions within the peritoneal cavity.

Question 34

What percentage of colon cancer cases are classified as primary?

Answer 34

54% of colon cancer cases are classified as primary.

Question 35

What is the most common lymphatic spread site for rectal cancer?

Answer 35

Rectal cancer most commonly spreads to internal iliac nodes.

Question 36

What is the recommended age to start a colonoscopy for colorectal cancer?

Answer 36

Age 45 ## Footnote Colonoscopy examines the entire colon and can visualize polyps.

Question 37

How often should a colonoscopy be done?

Answer 37

Every 10 years

Question 38

How often should a sigmoidoscopy be done?

Answer 38

Every 5 years

Question 39

What is a DRE?

Answer 39

Digital rectal exam

Question 40

How often should a fecal occult blood test (FOBT) be done?

Answer 40

Every 3 years

Question 41

What is carcinoembryonic antigen (CEA)?

Answer 41

A type of protein molecule that may be associated with certain malignant tumors such as colon and ovarian cancer.

Question 42

What type of cancer accounts for over 90% of colorectal cancer cases?

Answer 42

Adenocarcinomas

Question 43

What are the other types of tumors associated with colorectal cancer?

Answer 43

Leiomyosarcoma, Lymphoma, Carcinoid, Neuroendocrine cancer, Squamous cell carcinoma

Question 44

What are the main staging systems for colorectal cancer?

Answer 44

TNM, Dukes, Modified Astler-Coller ## Footnote TNM is most often used.

Question 45

What is the treatment of choice for rectal cancer?

Answer 45

The treatment of choice for rectal cancer is surgery.

Question 46

What is the most common site of colon cancer?

Answer 46

The rectum is the most common site of colon cancer.

Question 47

What does the surgical treatment for rectal cancer involve?

Answer 47

The tumor, adequate margin, and draining lymph nodes are removed.

Question 48

What are the two common surgical procedures for rectal cancer?

Answer 48

The two common procedures are Low Anterior Resection (LAR) and Abdominoperineal Resection.

Question 49

What is Low Anterior Resection (LAR)?

Answer 49

LAR involves the removal of the tumor plus a margin and the immediately adjacent lymph nodes. The bowel is then re-anastomosed, so a colostomy is not necessary.

Question 50

What is Abdominoperineal Resection?

Answer 50

Abdominoperineal resection is used for patients with rectal cancer in the lower third of the rectum.

Question 51

How is Abdominoperineal Resection performed?

Answer 51

An anterior incision is made into the abdominal wall to construct a colostomy.

Question 52

What is the most commonly used radiation therapy for colorectal cancer?

Answer 52

EBRT (External Beam Radiation Therapy) is most commonly used as adjuvant therapy.

Question 53

What is the recommended radiation dose if microscopic disease is left after surgery?

Answer 53

60 Gy is recommended if microscopic disease is left.

Question 54

What is the recommended radiation dose if gross disease is left after surgery?

Answer 54

70 Gy is recommended if gross disease is left.

Question 55

What dose may patients receive during an IORT procedure?

Answer 55

Patients may receive a dose of 1000 to 2000 Gy of electrons in a single fraction directly to the tumor bed.

Question 56

What is a common chemotherapy drug used for colorectal cancer?

Answer 56

5-fluorouracil (5-FU) is a common chemotherapy drug.

Question 57

Name two targeted therapies used in colorectal cancer treatment.

Answer 57

Bevacizumab and Cetuximab are two targeted therapies used.

Question 58

What is the patient position for radiation set-up in colorectal cancer?

Answer 58

Prone position

Question 59

What is the purpose of a full bladder during radiation set-up?

Answer 59

To displace the small bowel

Question 60

How is the reduction of the small bowel dose achieved?

Answer 60

Through patient positioning and positioning devices, bladder distention, multiple-shaped fields, and dosimetric weighting.

Question 61

What is given during simulation to assess the small bowel in the field?

Answer 61

Oral contrast

Question 62

What is the purpose of using contrast during simulation?

Answer 62

It allows blood vessels to be highlighted and assists in outlining lymph node groups at risk.

Question 63

What are the types of field arrangements used in radiation therapy of colorectal tumors?

Answer 63

4 field or 3 field (PA and Laterals)

Question 64

Name two types of radiation therapy used to treat colorectal cancer.

Answer 64

IMRT and VMAT

Question 65

What is a Belly Board used for?

Answer 65

The Belly Board is used for positioning a colorectal cancer.

Question 66

Can patients be positioned supine during treatment?

Answer 66

Yes, patients may be positioned supine if treated using volume-modulated arc therapy (VMAT) or intensity-modulated radiation therapy (IMRT).

Question 67

What is an advantage of the supine position?

Answer 67

The supine position is more stable and comfortable for the patient than prone.

Question 68

What is becoming a more commonly used approach for treating rectal cancer?

Answer 68

VMAT consisting of two full arcs is becoming more commonly used than 3D conformal prone treatment fields.

Question 69

What is the standard dose for treating rectal cancer?

Answer 69

The standard dose is 60-70 Gy.

Question 70

What are the critical structures for treatment of ascending or descending colon cancer?

Answer 70

The critical structures include the kidneys and the small bowel.

Question 71

What are the acute radiation side effects for colorectal cancer treatment?

Answer 71

Diarrhea, abdominal cramps and bloating, proctitis, bloody or mucus discharge, dysuria, perineal skin reaction, leukopenia, thrombocytopenia. ## Footnote GI and hematologic toxicities are increased when chemotherapy is also used with radiation therapy.

Question 72

What are the chronic radiation side effects for colorectal cancer treatment?

Answer 72

Radiation proctitis, radiation ulceration, persistent diarrhea, increased bowel frequency, fistula, urinary incontinence, bladder atrophy. ## Footnote The most common long-term complication is damage to the small bowel that results in enteritis, adhesions, and obstruction.

Question 73

What are recommended foods for patients receiving pelvic irradiation?

Answer 73

White bread, meat baked, broiled, or roasted until tender, macaroni, cooked vegetables, peeled apples and bananas.

Question 74

What foods should be avoided for patients receiving pelvic irradiation?

Answer 74

Whole-grain breads or cereals, fried or fatty foods, milk and milk products, raw vegetables, fresh fruit.