GI / Nutritional Part 2 (Colorectal cancer - Gastric carcinoma) Flashcards
What is the MCC of LBO in adults?
Colorectal cancer (CRC)
also the MCC of occult bleed
MCC of CRC?
colorectal cancer
adenomatous polyps
What are the 4 different stages of polyps concerning malignancy likelihood/development?
- Hyperplastic
- Tubular
- Tubulovillous
- Villous
From least likely to most likely to be cancerous (HTTV)
Villous are villains
What size of a colorectal polyp is concerning?
1 cm or greater
less than this = unlikely to be malignant
RF of CRC (non-genetic)
age > 50 yo
IBD
Obesity, smoking, ETOH
What type of IBD is MC for CRC?
UC
> Crohn’s
What are the genetic predospitions to CRC? (4)
1) Familial Adenomatous Polyposis (FAP)
2) Turcot Syndrome
3) Lynch Syndrome (Hereditary Nonpolyposis CRC)
4) Puetz-Jebher’s Syndrome
Familial Adenomatous Polyposis (FAP) is a genetic mutation of the _ gene
APC
adenomatous polyposis coli (APC) gene
tumor supressor gene
What are the characteristics of Familial Adenomatous Polyposis (FAP) and the resulting treatment?
adenomas of colon at childhood
almost all will develop colon cancer by age 45yrs; prophylactic colectomy best for survival
What are the characteristics of Turcot syndrome and how does it differ from FAP?
FAP-like syndrome + CNS tumors (medulloblastoma, glial tumors)
FAP on steroids
Inheritance pattern of Lynch Syndrome and genes affected?
Hereditary Nonpolyposis CRC
Autosomal dominant
LADS (lynch autosomal dominant syndrome)
loss of function in DNA mismatch repair genes (MLH1, MSH2/6, PMS3)
What are the age differences of Lynch Syndrome vs FAP?
1) Lynch occurs at a mean age of late 40s
2) FAP = childhood adenomas
Difference between type I and type II Lynch syndrome
1)type I: esp. seen on right side
2)type II: ↑ risk of extra-colonic cancers (esp. endometrial)
Inheritance pattern of Puetz-Jegher’s Syndrome and associated characteristics
Autosomal dominant (like lynch syndrome)
hamartomatous polyps, mucocutaneous hyperpigmentation (lips, oral mucosa, hands) – risk of breast/pancreatic cance
In general what are the common clinical manifestations of the 4 CRCs?
- Iron deficiency anemia
- rectal bleeding
- abd pain
- change in bowel movements
advanced disease: ascites, abdominal masses, hepatomegaly
Clinical manifestations of right sided (proximal) CRC
Just general CRC symptoms
chronic occult bleeding
Clinical manifestations of left sided (distal) CRC
bowel obstruction; present later & cause changes in stool diameter – may develop Streptococcus bovis endocarditis
What are the characteristics of LOW risk CRC? (3)
hint, one is the size
*pedunculated
*tubular
*<1cm
What are the characteristics of HIGH risk CRC? (3)
*sessile (flat)
*villous (finger-like projections)
*>1cm
1st line diagnosis of CRC
Colonscopy + bx
If you were to do a barium enema for CRC, what is classic finding?
apple core lesion
constriction of lumen
Tumor marker for monitoring CRC
CEA
Carcinoembryonic antigen
Screening age for CRC and 3 screening options
assuming no RF
45 yo
1) q 10 years for colonoscopy
2) q 1 year fecal occult blood testing alone
3) flexible sigmoidoscopy q5yrs + fecal occult blood testing q3yrs
Screening frequency for CRC with the following level of RF
1) low
2) high
3) mega
1) low risk: q5-10yrs
1-2 polyps, <1cm, tubular, low grade
2) high risk: q1-3yrs
≥3 polyps, ≥1cm, sessile/villous, high grade
3) mega risk: q2-6mo
≥10 polyps
You have Lynch Syndrome (or a FH?), what is the screening protocol?
colonoscopy q1-2yrs beginning at 20-25yrs
remember, cancer typically appears in 40s
You have FAP (or a FH?), what is the screening protocol?
flexible sigmoidoscopy annually beginning 10-12yrs
appears in childhood
Overall management of non-metastatic CRC
surgical resection followed by post-op chemo
radical vs endoscopic
chemo to destroy residual cells and prevent METS
Mangement of METS CRC?
Palliative chemo :(
What chemo is used for CRC?
FOLFOX
FOLFIRI
VGEF inhibitor (bevacizumab)
folinic acid and leucovorin Ca2+ is used in FOLFOX and FOLFIRI (along with other chemo agents)
MCC of gastroenteritis?
Viruses
rotavirus and norovirus
Length of subacute diarrhea
2-4 weeks
above this = chronic (4+ weeks)
below this = acute (< 2 weeks)
MCC of foodborne disease outbreak
Norovirus
Common locations to get norovirus?
Cruise ships and daycare
Overall, if you want to use diagnostics for viral gastroenteritis, what might you use?
PCR
also antigen tests and stool analysis
it seems
All viral gastroenteritis have supportive treatment as management, but this virus has a prevention
Rotavirus
VACCINATE YOUR KIDDOS
Which causitive organism for gastroenteritis holds a risk of Guillain-Barre? hemolytic uremic syndrome (HUS)?
GB = Campylobacter jejuni
HUS = E. coli, Shiga-toxin-producing (STEC)
only sometimes!
How might you get Campylobacter jejuni infection?
for bacterial gastroenteritis
Think dairy/ animal exposure
at camp drinking milk
poultry, unpasteurized milk, untreated water, new pets, dairy farms
Treatment of Campylobacter jejuni
Supportive typically
azithromycin x3d or erythromycin x5d can shorten duration when given early in illness
Symptoms of E. coli, Shiga-toxin-producing (STEC) and what should be monitored
hemorrhagic colitis w/ bloody diarrhea
monitor: CBC/BUN/Cr for HUS
Treatment of E. coli, Shiga-toxin-producing (STEC)
Supportive
abx not recommended d/t HUS risk!!!
Dx and treatment of C diff
DX: two-step:
1) enzyme immunoassay for glutamine
2) dehydrogenase w/ confirmatory toxin testing by NAAT or toxin immunoassay
Metro for mild
Vanc for severe
Fidaxomicin for continuous relapse
What is the causitive agent for traveler’s diarrhea? Symptoms?
E coli
s/s = watery diarrhea + abd cramps
Treatment of E coli induced gastroenteritis
Traveler’s diarrhea
azithromycin or cipro x3d may ↓ duration
Complications of non-typhoid salmonella?
Spread of infection systemically
salmonella = systemic
bacteremia, osteomyelitis, brain abscess, meningitis
Tx of non-typhoid salmonella
Rocephin + azithromycin OR amoxicillin OR bactrim
ONLY in patients with high risk of systemic disease: 3mo, chronic GI dz, HIV/immunocompromised
What are the hosts for salmonella typhi and the presentation?
Humans
sys symptoms + bloody diarrhea, then HSM & rose spots by wk2
humans are the only natural hosts!
Treatment of salmonella typhi
Rocephin OR Azithromycin
+/- steroids in kiddos with enteric fever
monotherapy unlike non-typhoid salmonella?
Common outbreak location of shigella and s/s
Daycare
s/s vary - watery or bloody diarrhea w/ systemic symptoms
Treatment of shigella
rocephin OR azithromycin OR FQ
What is the causative agent of gastroenteritis that leads to this characteristic finding - “rice water diarrhea”?
Vibrio cholerae
Apart from rice water diarrhea, what are the symptoms of Vibrio cholerae and why does this make sense?
LOTS of watery diarrhea with no pain, but electrolyte abnormalities
from losing soooo much liquid
Treatment of Vibrio cholerae
Rocephin OR Azithromycin OR Cipro OR Tetracycline
very similar to shigella
What bacterial enteritis is often cause by exposure to any of the following:
SWINE; pork, milk, well water, chitterlings, tofu
Yersinia enterocolitica
uncommon in US
What is Yersinia enterocolitica often mistaken for?
Appendicitis
very similar s/s - but bloody diarrhea is seen!
Treatment of Yersinia enterocolitica
parenteral 3rd gen ceph, Bactrim, aminoglycosides, FQs, tetracycline, doxy, chloramphenicol – only for neonates/IC
What are the two common causes of parasitic gastroenteritis?
Giardia lamblia
Entamoeba histolytica
What is Giardia lamblia aka and what exposures often lead to it?
backpacker’s diarrhea
daycare, camping trips, contaminated water
s/s of Giardia lamblia
acute – watery diarrhea, foul-smell, flatulence, anorexia; can lead to FTT
treatment of Giardia lamblia
tinidazole x1, metronidazole x5-10d, nitazoxanide x3d
remember, parasitic
What are the s/s of Entamoeba histolytica caused by? How does this present?
intestinal amebiasis
gradual onset bloody diarrhea, lower abd. pain, tenesmus, wt loss; complications: toxic megacolon, fulm. colitis
Dx and treatment of Entamoeba histolytica and why this makes sense
Stool O&P
metronidazole then paramomycin
remember, fungal
What antidiarrheal is indicated in patients with inflammatory diarrhea?
Bismuths
antimicrobial properties; salicylate: anti-secretory & anti-inflammatory properties
Apart from pepto, what is another bismuth?
Kaopectate
pectate kinda sounds like pepto
SE of bismuths and CI
dark colored stools, darkening of tongue
CI in kiddos d/t Reye’s syndrome (because salicylate)
What two antidiarrheals bind to gut opioid receptors, thereby decreasing peristalsis? Which one increases anal sphincter tone as well?
Diphenoxylate and loperamide
loperamide also increases anal tone
should not be used in inflammatory diarrhea as a result!
Indications for Diphenoxylate and loperamide
non-invasive diarrhea
watery/non-bacterial?
Why use anticholinergics for diarrhea and what are they?
Decreases gut secretions (can’t poop)
inhibits Ach-related GI motility
Phenobarbital, Hyoscyamine, Atropine, Scopolamine
MOA of zofran and suffix of generic names?
blocks serotonin receptors
-setron meds (sim to serotonin)
SE of -setron (anti-emetic anti-cholinergic) meds
neuro: HA, fatigue, sedation
cardiac: QT prolongation, arrhythmias
GI: bloating, diarrhea, constipation
What are the dopamine blockers used as anti-emetics? (3)
Prochlorperazine
Promethazine
Metoclopramide
blocks CNS dopamine receptors; mild antihistaminic/antimuscarinic
SE of dopamine blockers used as anti-emetics?
QT prolongation, anticholinergic, drowsiness
also EPS: rigidity, bradykinesia, tremor, akathisia, parkinsonism: rigidity, tremor
Treatment of dystonic reactions (dyskenesia) from EPS 2ndary to dopamine blockers
IV diphenhydramine
Benadryl
MCC of ACUTE lower GI bleed
diverticulosis
chronic = CRC, remember :)
Diverticulosis is outpouchings due to herniation of the mucosa into the wall of the colon along natural openings at the () of the colon
vasa recta
Most common location vs site of bleeding for diverticulosis
Location = Left colon
Bleeding site = Right colon
MC location of diverticulitis
sigmoid colon
remember, this is at the LLQ, which is why you feel pain there!
Dx of diverticulosis vs diverticulitis
diverticulosis = incidental colonscopy
diverticulitis = CT w/ IV contrast after characteristic symptoms
Treatment of diverticulitis
Metro + cipro OR levaquin for uncomplicated
with a clear liquid diet
Surgery: refractory to medical therapy, frequent recurrences, perforation, strictures
MCC of Esophageal Neoplasms in US vs worldwide
US = adenocarcinoma
WW = squamous cell
MC location of esophageal adenocarcinoma VS squamous cell
adenocarcinoma = distal esophagus, esophagogastric junction
squamous cell= mid to upper third of the esophagus
which esophageal neoplasm can be a complication of barret’s esophagus?
adenocarcinoma
What are the characteristic findings of an esophageal neoplasm?
*progressive dysphagia – solid food dysphagia progressing to include fluids
*odynophagia
*weight loss
think esophageal problems
Dx of esophageal neoplasms
Upper endoscopy w/ bx
Management of esophageal neoplasms
Resection + chemo OR
radiation + chemo (5-FU)
palliative stenting (advanced)
Management of Barrett’s
endoscopic eval q3-5yrs
watchful waiting and observing the esopahgus
What esophageal disease can lead to Plummer-Vinson Syndrome and what is it? Why is it a concern?
Esophageal Strictures
*dysphagia + webs + iron deficiency anemia
*may be associated w/ atrophic glossitis
*increased risk for esophageal SCC
MC location of esophageal webs vs Shatzki Rings?
Esophageal Strictures
Esophageal Web = mid-upper esophagus
Shatzki Ring = lower esophagus (at the squamocolumnar junction)
Rings fall down d/t gravity
Webs can attach high in the sky
Risks of Esophageal Strictures
hiatal hernia
d/t compromised anatomy?
MC symptom of Esophageal Strictures
be specific
Dysphagia (esp. to solids)
Diagnosis and treatment of Esophageal Strictures
Barium esophagram (swallow)
Symptomatic: dilation
MC gastric carcinoma and biggest RF
Adenocarcinoma
H. pylori biggest risk factor
MC symptoms associated with gastric carcinoma
weight loss & persistent abdominal pain
early satiety also seen
think what would happen if your stomach was having issues
What are the palpable LNs sometimes associated with gastric carcinoma
*supraclavicular lymph nodes (Virchow’s node)
*umbilical LN (Sister Mary Joseph’s node)
*left axillary LN (Irish sign)
*palpable nodule on rectal exam (Blumer’s shelf)
Diagnostic of choice for gastric carcinoma and what imaging is used for METS
Upper endoscopy w/ bx standard
Abdominal/pelvic CT (METS)
CXR sometimes
What are the lab findings characteristic of gastric carcinoma? (2)
1) microcytic/hypochromic anemia
2) + guaiac
iron deficiency anemia?
Treatment of early local disease gastric carcinoma
endoscopic resection
other therapies depending on location and course of disease (gastrectomy, chemo, radiation)
