colorectal cancer Flashcards
risk factors for colorectal cancer
age (>50)
Ashkenazi Jewish highest risk, African American
History of bowel disease/polyps (UC, Crohn’s)
Diet (high fat, low fiber, alcohol, low antioxidant/calcium/Vitamin D)
obesity, physical inactivity
diabetes
HNPCC, FAP
inherited conditions giving you high risk of colorectal cancer
- Hereditary non-polyposis colorectal cancer (HNPCC): 80% risk of developing colon cancer by age 44
- Familial adenomatous polyposis (FAP): 100% risk of developing colon cancer (average age 39)
specific screening guidelines for colorectal cancer
beginning at age 45 (earlier if high risk)
-yearly blood stool test (FOBT) or fecal immunochemical test (FIT) AND one of the following: flexible sigmoidoscopy, double contrast barium enema, CT colonography every 5 years, or colonoscopy every 10 years
when do you screen at a younger age?
family history of HNPCC: age 30
family history of FAP: puberty
UC or Crohn’s: 8 years after onset of pancolitis
Colorectal cancer or polyps in a 1st degree relative: age 40 or 10 years before youngest case in family, whichever is earlier
personal history of adenoma w/ polypectomy: 3 years after initial
importance of KRAS mutational status
if wild type: may respond to anti-EGFR therapy
if mutant: will be unresponsive, and worse prognosis
KRAS vs BRAF implications in therapy?
KRAS mutation= resistance to EGFR inhibitors
BRAF mutation= resistance to chemotherapy
1st line combo therapy for colorectal cancer
FOLFOX: fluorouracil, leucovorin, oxaliplatin
agents that target EGFR
what is the CRC marker?
cetuximab
panitumumab
CRC marker is KRAS wild-type
agents that target VEGF
bevacizumab
ramucirumab
Ziv-Aflibercept (a decoy receptor)
agents that target PD1 with CRC marker microsatellite instability high (MSI-h)
pembrolizumab
nivolumab
agents that target CTLA-4
what is the CRC marker?
ipilimumab
CRC marker is microsatellite instability high (MSI-h)
agents that target PD1 with CRC marker deficient mismatch repair (dMMR)
dostarlimab
agent that is a VEGF receptor inhibitor
regorafenib
agent that is a BRAF inhibitor
what is the CRC marker?
encorafenib
CRC marker is BRAF V600E mutation
agents that target HER2 and what is the CRC marker
trastuzumab
lapatinib
tucatinib
pertuzumab
CRC marker is HER2 positive tumors