Colorectal Cancer Flashcards
What does colon cancer normally begin with?
- Almost all cancers are thought to arise from a polyp
What are some risk factors for developing colon cancer?
A. Age
a. Rises sharply after 45, and almost all cases occur over the age of 50
B. Fam Hx
C. Inflammatory Bowel Disease
a. Begins to rise about 8 years past the onset of Crohns or UC. Screening is important
D. Dietary Factors and Chemoprevention
a. Diets rich in red meat and fats are associated with colorectal carcinomas.
b. Diets high in fruits, veggies, and fiber are at a decreased risk
c. Prolonged NSAID use is also associated
E. Other Factors
a. Blacks > whites
b. DM, smoking, metabolic syndrome associated
What KIND of cancer is most colon cancer?
adenocarcinoma. It tends to be slower growing.
What are some clinical signs that you may have a Right sided colon cancer?
chronic blood loss→ anemia, fatigue, weakness
What are some clinical signs that you might have a left sided colon cancer?
Left Sided Colon Cancers: smaller in diameter, often involved obstructive symptoms: colicky pain, change in bowel habits. Sometimes stool is marked blood, although not required
What will a physical exam reveal for colon cancer?
Physical Exam is usually unremarkable until late in the disease. Sometimes a palpable mass is felt
What are the two types of colorectal polyps?
- hyperplastic –> not cancerous precursor
2. adenoma –> important precursor
Cancer arises from what type of polyp? How can risk of cancer be reduced?
most arise from adenomatous polyps, and you should excise them to decrease risk.
What labs are indicated in colon cancer?
a. CBC → anemia
b. Elevated liver tests→ (esp alkaline phosphatase) usually suspicious for metastizes.
c. CEA level
i. Should normalize after resection
ii. >5 ng/mL is not a good prognosis
What is Familial Adenomatous Polyposis syndrome?
It is an autosomal dominant disease. It is on chromosome 5q APC gene. By age 30-40, there are 100’s of adenomas present in the colon. If this goes untreated, by age 40-50 there is a 100% chance of colon cancer. Tx: removal of colon
What is HNPCC or Lynch Syndrome?
It is a hereditary non polyposis colorectal cancer. It accounts for 5-10% of colon cancer. Familes with HNPCC have a 70-90% chance of developing colorectal cancer. Usually diagnosed with colon cancer around 45 years old. Genetic testing is available.
What are some symptoms of colon cancer?
change in bowel habits, bright red or dark stool, stools that appear narrow or thinner than others, discomfort in the abdomen, including frequent gas, pains, bloating, fullness and cramps. Unexplained weight loss, tiredness.
What is the number one best way to screen for colon cancer?
colonoscopy
Where are most colon cancers located?
2/3 are found in the descending colon
What are the current guidelines for screening of colon cancer?
M and W after age 50…
1. fecal occult blood test annually or flexible sigmoidoscopy every 5 years
or
2. colonscopy every 10 years
or
3. double contrast barium enema every 5 years.