GI Neoplasia Flashcards
what is interchangeable with carcinoma in situ?
intraepithelial neoplasia
malignancy is defined by?
invasion/metastasis
aneuploidy?
more than 2 chromosomes, inappropriate numbers: chromosomal instability
proto-oncogenes need one or two hits?
one hit
how many hits for TSGs?
two hit
P53 active between which cell phases?
G1 and S
G2 and M
RBactive between which cell phases?
G1 and S
carcinoma is cancer of?
epithelium
sarcoma is cancer of?
mesenchymal
dysplasia signs? 3
disordered
premalignant lesion
mutations
cancer is defined by?
invasion and breach of basement membrane to stroma
bone is a common site for breast and prostate possibly due to?
similar micro environment
example of physiological metaplasia?
cervical transformation zone during menstrual cycle
pathological metaplasia in oesophagus?
barrett’s oesophagus due to chronic GORD
HPV is only on cervix?
ubiquitous: >150 serotypes
What are the high risk cancer HPVs?
16 and 18
What are the low risk cancer HPVs?
6 and 11
what part of HPV genes leads to cervical cancer?
E2 gene disruption during viral genome integration leads to too much E6, E7 then loss of p53 and Rb tumour suppressors
What does HPV E6 and E7 oncoproteins do?
inhibits tumour suppressor protein
cervix intraepithelial neoplasia increased risk are which 2 categories?
ClN2 and ClN3
diagnostic criteria for Barrett’s oesophagus?
endoscopic evidence of columnar
histo: metaplasia (goblet cells)
what gives you an increased 10% lifetime risk of oseophageal adenocarcinoma?
Barrett’s oesophagus
What is the most common familial colorectal cancer syndrome?
Lynch Syndrome
gland fusion or fusion with lamina propria is a feature of?
malignancy
what happens to nucleus of dysplastic cells?
loss of polarity
nuclear atypia
dysplastic changes to basement membrane?
separation of basal cell layer
fused glands in mucosa indicates what?
lamina propria invasion
what is a pre-invasive term for severe dysplasia?
carcinoma in situ
is there metaplastic precursor in breast ductal carcinoma in situ?
Nope.
breach in what = invasive carcinoma for cervix?
basement membrane
breach in what = invasive carcinoma for prostate?
basal cell layer loss
breach in what = invasive carcinoma for breast?
myoepithelial cell layer loss
breach in what = invasive carcinoma for oesophagus?
basement membrane
breach in what = invasive carcinoma for colon?
muscularis mucosae
4 ways of carcinoma spread?
direct
lymphatic
vascular
perineural
what are adenomatous dysplastic polyps?
precursor lesions
Are Tubular adenoma/villous adenoma invasive? what are their features
nope. precursor, no invasion
Tubular: sessile/pedunculated
Villous: large/sessile
if the polyp is >1cm and high grade dysplasia then what?
increased risk of malignancy
cancer risk if you have Familial adenomatous polyposis?
100%
cancer risk if you have lynch syndrome?
70-80%
Familial adenomatous polyposis recessive or dominant?
dominant
where are the lymphatics in the colon?
not in the lamina propria
how to treat adenomatous polyps?
complete excision
are adenomatous polyps invasive?
no invasion beyond muscularis mucosae
are hyperplastic polyps benign? or malignant?
benign
at what point do you get colorectal adenocarcinoma?
invasion beyond muscularis mucosae
what happens to stroma witth colorectal adenocarcinoma?
desmoplastic stromal reaction
3 colorectal cancer pathways
Chromosomal instability microsatellite instability (MSI) CpG island methylator phenotype (CIMP)
which TSGs are lost in carcinoma?
p53
SMAD4/SMAD2
which proto-oncogenes are lost in carcinoma?
K-RAS
what is the most common familial colorectal cancer syndrome?
Lynch Syndrome
Lynch Syndrome dominant or recessive? onset of cancer?
dominant
mean age 45
extracolonic cancers in Lynch Syndrome?
yes
endometrium
renal pelvis
2 things in micro satellite instability pathway?
defective DNA mismatch repair
widespread mutations in DNA micro satellites
where do sessile serrated adenoma/polyps usually arise?
proximal colon
sessile serrated adenoma/polyps easy or heard to detect?
hard to detect at colonoscopy
what is serrated in sessile serrated adenoma/polyps ?
elongation and serration of crypts
How do colorectal cancers grow in:
1. proximal colon
2. distal colon
why?
- bulky, polypoid: due to more liquid stool
2. annular, stenosing, ulcerated: due to more solid stool
invasion assessment of colon cancer. 4 things
muscularis muscosae
lymph nodes
infiltration of adjacent organs
perforation into peritoneal cavity
Australian staging for colorectal cancer: ACPS A ACPS B ACPS C ACPS D
ACPS A: beyond muscularis mucosae
ACPS B: beyond muscularis propria
ACPS C: lymph node metastasis
ACPS D: distant metastase
TMN staging is?
Tumour invasion Tis, T1,2,3,4
Node metastases: N0,1,2
M etastases: Mx, M0,1
what organ is common site of metastases for colorectal cancer?
liver cause of portal system
neoadjuvant therapy is? Grade 1 is best or worse?
pre-operative chemoradiotherapy
grade 1 is complete tumour destruction
early onset cancer should raise suspicion of?
underlying syndrome
2 things that dysplasia has histologically:
nuclear atypia
disordered growth
complete excision of dysplasia will cure?
yes
Cetuximab and panitumumab block what?
EGFR signalling
K-RAS and B-RAF mutation predicts what?
poor response to EGFR-targeted therapy so need to screen before targeted therapy
Colorectal sequence:
normal, then get first hit (APC) dysplastic early adenoma (K-RAS) intermediate adenoma (SMAD4) late adenoma (p53) carcinoma metastasis