29. Colorectal Cancer Flashcards
true or false: colorectal cancer is the most common malignancy
false - third most common
what are some risk factors of colorectal cancer
- age (risk increases > 40, but most cases are > 50)
- family hx of colorectal cancer
- personal hx of colorectal cancer
- IBD
- lifestyle (smoking, T2DM, western diet, alcohol, obesity)
- hereditary (hereditary nonpolyposis colorectal cancer - HNPCC and familial adenomatous polyposis - FAP)
what are the early symptoms of colorectal cancer
- blood in stool (hematochezia)
- black tarry stools (melena)
- abdominal pain
- change in bowel habits
what are the common metastatic sites of colorectal cancer
liver, lungs and peritoneum
if someone has colon cancer, where are the metastasis most likely to initially present?
due to venous drainage of the intestinal tract via the portal system, the first site is usually the liver
if someone has a tumor that arises from the distal rectum, where are the metastasis most likely to initially present?
the inferior rectal vein drains into the inferior vena cava therefore usually metastasize to the lungs first
what are the major screening tests used for colorectal cancer
FIT test, sigmoidoscopy, barium enema and colonoscopy
how are average risk individuals aged 50 - 74 screened for colorectal cancer?
FIT test
explain what test is used to screen high risk individuals for colorectal cancer
- if a patient has ONE first degree relative that was diagnosed with colorectal cancer under the age of 60 -> colonoscopy
- if a patient has TWO first degree relatives with colon cancer -> colonoscopy
- if a patient has one family member diagnosed over the age of 60 with colorectal cancer -> FIT test
- distant family members with colon cancer -> FIT test
the vast majority of colorectal cancers are __________ that arise from the mucosa
endoluminal adenocarcinomas
true or false: CEA is used to diagnose colorectal cancers
false - CEA has a low diagnostic ability as there are many non-cancer related causes of an elevated CEA
true or false: most colorectal cancer develop in the glandular cells in the inner lining (mucosa) of the colon or rectal wall, either on the wall itself or within a polp
true
know the stages of colorectal cancer
stage I - confined to bowel mucosa / no bowel wall involvement
stage II - extended through bowel wall / no lymph node involvement
stage III - lymph node involvement
stage IV - distant metastases
the most reliable prognostic factor for colorectal cancer is
the stage
fwhat are some negative prognostic factors for colorectal cancer
- high grade
- increased CEA levels at time of diagnosis
- degree of tumor perforation through bowel wall
- > 4 nodes involved
- rectal cancer has worse prognosis than colon cancer
- lymphovascular invasion
what is the treatment for stage I colon cancer
surgery
what is the treatment stage II colon cancer
surgery +/- adjunct chemo
what is the treatment of stage III colon cancer
chemo + adjunct chemo x 6 months
what is the treatment of stage IV colon cancer
palliative chemo
what is the treatment of stage I rectal cancer
surgery
what is the treatment of stage II rectal cancer
surgery + adjuvant chemo x 6 months + rads
what is the treatment of stage III rectal cancer
surgery + adjuvant chemo x 6 months + rads
what is the treatment of stage IV rectal cancer
palliative chemo
if a patient has high risk stage II or stage III colorectal cancer, when should their chemo be started with regards to when they had they’re surgery
start chemo 8 weeks after surgery
