Week 5: Hereditary Colorectal and Polyposis

Colorectal Cancer is the ___ most commonly diagnosed cancer among both men and women

3rd

Males have a __in__ risk of CRC

1 in 26

Males have a __in__ risk of CRC

1 in 24

What is the shifting age incidence trend for CRC?

shifting younger but the trends are driven by older individuals who have the highest rates

-risk of disease is rising by 2.4% per year in those <50y

Localized survival rate

cancer confined to rectum

91% colon

90% rectal

Regional survival rate

cancer has spread to nearby tissues or lymph nodes

73% colon

74% rectal

Distal survival rate

Has spread to further parts of the body

13% colon

18% rectal

Proximal colon

cecum, ascending, transverse colon

Distal colon

descending colon, sigmoid, and rectum

What is the majority made of?

colon

5 feet long

The rectum

the final 6 inches of the digestive system

What is the biggest risk factor for CRC?

Family HX of CRC

WHat percent of all CRC are caused by lifestyle factors?

55%

about ___ of people dx with CRC have a family history of the disease

30%

Having FDR with CRC leads to a ___ times risk to develop CRC

2-4

Most CRC start as a ___

polyp

How long do polyps take to grow and become cancerous?

10-15yrs

What is the most common type of polyp?

Adenocarcinoma (90%)

What are the subtypes of adenocarcinomas?

Mucinous adenocarinoma (10-15%)

Signet ring cell - <1% of all colon cancers - aggressive

Rare types of polyps found in the colon or rectum?

Carcinoid tumors

neuroendocrine

primary colorectal lymphoma

Colorectal sarcomas

Melanoma

Different descriptions of polyps?

Pedunculated

Sessile

Serrated

Pedunculated

Mushrrom

easy to remove

Sessile

Flat or dome shaped

more likely to be cancerous

Serrated

Saw-toothed appearance

Have a significant increased risk

Types of polyps HAS

Hamartomatous

Adenomatous

Serrated

Adenomatous Polyps types

Tubular (most common -80%)

Tubulovillous

Villous adenomas (least common)

Approximately how many of all colonic polyps adenomas?

2/3

Larger adenomas with a ____ growth pattern are more likely to have cancer cells in them

villous

Do all adenomas have some degree of dypslasia?

yes

Types of serrated polyps

Sessile Serrated - most common precancerous

Traditional serrated

Hyperplastic - most common

Where are serrated polyps found?

usually in sigmoid colon and rectum

serrated polyps cause about __ of colon cancers and _ of colon polyps

20-30%

15%

Hyperplastic polyps

most common non-neoplastic polyps in colon

found in 7-40% of people

75% of serrated polyps

Low risk

End of colon and the rectum

Hamartomatous Polyps JIP

Juvenile polyps - most common polyp in children

Intestinal ganglioneuromas

Peuts Jeghers

Hamartomatous polyps malignancy

Rarely malignant but can transform into cancer

What kind of polyps are common in people with inflammatory bowel disease

Crohn’s disease or ulcerative colitis

(low risk)

Factors that can make a polyp more likley to contain cancer?

Size - larger than 1 cm

Number - more than 3 polyps

Histology - cells look abnormal

Screening for CRC

Colonoscopy, sigmoidoscopy, CT colonography, stool tests

Colonoscopy

thin, flexible,lighted tube to check for polyps

views the entire RECTUM and ENTIRE COLON

Most effective way to screen for early stage CRC

Requires full prep

Polyps CAN BE REMOVED

NCCN gen pop colonoscopy recs?

47-75 years every 10 years

Sigmoidoscopy

short, thin, flexible, lighted tube to check for polyps

View inside the rectum and LOWER THIRD of colon

CT colonography

Virtual colonoscopy

used x-rays - small exposure to radiation

full prep needed

CANNOT REMOVE POLYPS

-repeat every 5 years if negative

Stool tests

Guaic-based fecal occult blood test

Fecal immunochemical test

FIT-DNA test

gFOBT

Finds hidden blood in the stool

• cannot determine if blood is from the colon or other part of GI

• MUST BE DONE EVERY YEAR

• some foods can impact results

FIT

Finds hidden blood

-done every year

-Can be + from ulcers or hemmorrhoids

—> not affected by foods and drugs

FITDNA test (cologuard)

Looks for ABNORMAL SECTIONS OF DNA or hidden blood

-EVERY 3 years

—> NO drug or dietary restrictions before testing

DX of CRC?

symptoms —> colonoscopy

What is a early warning sign of CRC cancer

Iron deficiency anemia (50% colon), (30% rectal)

Why anemia?

bc angiogenesis and new blood vessels are fragile and burst easily

—> as the tumor grows larger, bleeding and blood loss becomes worse

Slow blood loss is characterist of tumors located on what side of the colon?

Right

Treatment for CRC?

Surgery is the main treatment

Colectomy

Types of colectomies?

Total -remove entire

Partial - leaving part of colon

Hemicolectomy - removing left or right portion of colon

Proctocolectomy - removing both colon and rectum

What is an ostomy?

ileostomy or colostomy - creates new pathway for waste

Protocolectomy

J-pouch surgery - J-shaped pouch collects wast

Benign colon disease

IBD - Ulcertative colitis, crohn disease

—> increased risk of colorectal cancer risk

Diverticulitis

Inflammation of diverticula

diverticula = small , bulging pouches that form the wall of the colon