248b GI cancers Flashcards Preview

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Flashcards in 248b GI cancers Deck (13):
1

colorectal cancer - what genetic syndromes predispose people to CRC? what is mutated? other components?

FAP - AD APC gene mutation on 5q; pancolonic (+ rectum) with 1000's of polyps at young age; all progress to CRC

Gardner - FAP + osseous and soft tissue tumors, dark retinal pugmentation

Turcot - FAP + malignant CNS tumor (turcot = turban)

HNPCC/Lynch syndrome - AD DNA mismatch repair genes; 80% progress to CRC; proximal colon always involved

2

risk factors for CRC

IBD
tobacco
large villous adenomas
JPS
Peutz-jeghers syndrome

3

pancreatic adenocarcinoma - where does it arise from? what part of pancreas? tumor marker?

pancreatic ducts --> disorganized glandular structure w/ cellular infiltration

more common in pancreatic head --> obstructive jaundice

CA-19-9

4

pancreatic adenocarcinoma - prognosis? risk factors?

death within 1 year

tobacco #1 risk factor

chronic pancreatitis

DM

Age > 50

Jews and AA males

5

pancreatic adenocarcinoma - presentation?

abdominal pain radiating to back

weight loss (due to malabsorption and anorexia)

Trousseau syndrome --> migratory thrombophlebitis (red, tender on palpation of extremities)

obstructive jaundice w/ palpable, nontender gallbladder

6

CRC most common location? presentation based on location?

rectosigmoid > ascending > descending

ascending - exophytic mass (grows outward), iron deficiency anemia, weight loss (obstruction)

descending - infiltrating mass, partial obstruction, colicky pain, hematochezia (red blood)

7

CRC molecular pathogenesis

2 pathways --> CRC

1) microsatellite instability pathway (15%): DNA mismatch repair mutation --> sporadic and HNPCC

2) APC/B-catenin (chromosomal instability) 85% --> sporadic cancer

Order of gene events= AK-53: APC loss (colon at risk) --> K-RAS mutation (adenoma) --> p53, DCC (carcinoma)

8

how long does CRC take to develop?

10-15 years

9

follow up marker for CRC?

CEA (carcinoembryonic antigen)

10

tumor vs stone blocking bile duct in pancreas?

tumor - no pain, obstructive jaundice

stone - very painful

10

tumor vs stone blocking bile duct in pancreas?

tumor - no pain, obstructive jaundice

stone - very painful

11

what is activated that causes pancreatitis?

premature activation of trypsinogen

11

what is activated that causes pancreatitis?

premature activation of trypsinogen