MCT Flashcards
In dogs treated with DRT for MCTs, what is the difference in DFI for dogs w microscopic disease vs. gross disease?
54 vs. 12 mos.
gross dz dogs live longer if mass is < 9 cm3
The local recurrence rate for dogs receiving DRT for MCTs ranges from:
5 to 20%
Using prophylactic LN irradiation for the treatment of canine MCT has what effect on MST/DFI/DFS?
No significant difference
In a study of dogs w cutaneous MCT & LN mets, what was the median DFI when given 57 Gy to local site & metastatic LNs?
41 mos
had late effects
In a study of incompletely resected Gr III MCTs using DRT of 2.88 Gy x 18, what was: MST? Median DFI? 1 yr local control % 2 yr local control %
28 mos
28 mos
65%
26%
In a study of 44 dogs with oral, perioral, & mucocutaneous MCT,
What % of dogs had LN mets on admission?
MST for dogs w LN mets vs. w/o mets?
Overall MST?
59%
14 mos vs. >36 mos (NR)
52 mos
(Hillman)
In a study of 24 dogs w MCT on the muzzle, it was found that tumors in this location have HIGHER or LOWER risk of metastasis vs. MCTs on the extremity & trunk?
HIGHER
Geiger
In a study of 17 dogs using PRT + Palladia + pred for MCTs not amenable to surgery, what was the:
ORR?
Median PFI?
Median time to max response?
76%
10 mos
1 month
In a study of 17 dogs using RT + Palladia + pred for MCTs not amenable to surgery, what % GI toxicity and hepatotoxicity?
Severity of RT-induced effects?
100%
80%
Minimal
In a study of 17 dogs using RT + Palladia + pred for MCTs not amenable to surgery, what were the effect of the presence of mutant c-KIT on:
PFI?
Survival time?
decreased PFI
no difference in ST
A significant number of MCTs have mutation in the c-KIT gene involving what exons?
8 (etracellular domain), 9, 11, 12 (juxtamembrane)
c-KIT mutation apear in 25-30@ of Gr II/III MCTs
Histamine release from MCT granules act on what receptors?
Dogs w MCT have increased plasma histamine and decreased what?
parietal cells via H2 receptors resulting in HCl secretion
plasma gastrin levels
MCTs stain positive to which 3 stains?
vimentin
tryptase
CD117 (KIT)
In dogs with undifferentiated MCTs, what % range are metastatic?
Most die within what time?
55-96%
most die ≤ 1 yr (Gr III)
What MI is used as a cut off for difference in MCT survival?
What are the MST above and below this point?
5
If MI ≤ 5, MST = 80 mos
If MI > 5, MST = 3 mos
The presence of c-KIT mutations in MCTs correlates with increase in what 3 things?
recurrence
metastasis
death due to disease
Of the following locations, in which ones do reports support association with more aggressive behavior: preputial, inguinal, subungual, mucocutaneous, muzzle, scrotal, preputial, oral.
Muzzle, scrotal, preputial
Regarding SQ MCT in the dog without c-KIT mutations, what are the 2 yr and 5 yr survival?
92%
86%
Regarding SQ MCT in the dog, list 3 histologic features associated with decreased survival.
MI > 4
infiltrative growth pattern
multinucleation
For dogs with visceral MCT, name a symptom at diagnosis that decreased survival. What was the MST for these dogs?
systemic clinical signs
3 mos
What is the recurrence rate of incompletely excised Grade II MCTs in the dog?
23%
What is the benefit to adjunct steroids in cases of complete excision of canine MCTs treated w Sx + RT?
None
Regarding canine MCTs, list 3 situations where patients should be treated as if there is a high capacity for metastasis
- Intermediate tumors w mets
- high MI
- mucocutaneous
In dogs with MCTs, prednisone as the sole tx has what ORR?
70-75%
Pred causes apoptosis, decr. growth & reproduction rate of tumor cells
NOT cytotoxic
Ancillary tx of MCTs involves use of drugs related to agents released by MCT granules. Name the classes of drugs and give examples
H1 blockers - diphenhydramine, chlorpheniramine
H2 blockers - cimetidine, famotidine, ranitidine
PPI - omiperazole; use w gross disease
Protamine sulfate - heparin antagonist used in cases of hemorrhage
Are SQ MCTs in dogs MORE or LESS aggressive than dermal MCTs?
Does the Patnik scale apply to SQ MCTs?
LESS
No
(8% local recurrence, median DFI = 68 mos
Regarding grading MCT, the Kiupel system (two tier) considers high grad to have what 4 features? (???)
- > 7 MI/10 HPF
- ≥ 3 multinucleated cells/10 HPF
- ≥ 3 bizzare nuclei/10HPF
- karyomegaly
In a study of cats with cutaneous MCTs treated w Sr-90ß irradiation +/- steroids:
MST?
local control?
did any cats die of disease?
36 mos
98%
No
In cats, MCTs with a high MI correlates with what 3 things?
recurrence
survival
2nd MCT development