MCT Flashcards
What’s the best-described genetic abnormality for canine MCT?
c-kit mutation.
- Kit = tyrosine kinase
- ligand = SCF
- mutation will lead to autophosphorylation.
- in the juxta membrane domain (exons 11-12) or the extracellular domain (exons 8-9)
What % of dogs will have multiple MCT on presentation?
11-14%
What’s the % of GI ulceration in dogs with MCT on necropsy?
35-83%
What mediator is thought to be responsible for hypotension during MCT degranulation?
Prostaglandin D
What’s AgNOR and how does that influence outcome in canine cutaneous MCT?
It’s a measure of the speed of cell cycle progression.
- Average AgNORs per cell < 1.7: No dogs died due to MCT-associated disease
- Average AgNORs per cell > 2.25: Significantly decreased survival
- Average AgNORs per cell > 4: Significantly decreased survival:
– 66.7% of dogs died from MCT-associated disease
– MST 17 weeks
What’s ki67 and how does that influence outcome in canine cutaneous MCT?
It’s a measure of numbers of cells that are actively dividing.
- >23 per grid area = shorter survival time
What’s Ag67
it’s the product of AgNOR and ki67
- if it’s >54 = shorter DFI
- increased risk of MCT mortality and metastasis
- significantly associated with an increased incidence and
rate of MCT recurrence at the original surgical site:
– 40% of dogs died due to MCT before 12 months postdiagnosis
What’s the metastatic rate of undifferentiated canine MCT?
55-90%; most will die of MCT within a year
What’s the outcome with MI < 5 vs > 5 for canine MCT?
< 5: MST = 80 months
> 5: MST = 3 months
What are 3 negative prognostic indicators for canine SQ MCT?
- MI > 4
- infiltrative pattern
- presence of multi-nucleation
What’s the LN metastatic rate of muzzle MCT in dogs?
50%, but can still live for 14 months
In what scenario is LN metastasis going in limit the survival time for canine MCT?
if the primary tumour is undifferentiated, then if there is also LN met, the MST = 194d compared to 503d. Treatment of the LN improves survival (240 vs 42 days).
Describe the MCT staging system.
Stage 0: microscopic, incompletely removed, no mets
Stage 1: single cutaneous mass, no LN mets
Stage 2: single cutaneous mass with regional LN metastasis
Stage 3: multiple cutaneous masses; large infiltrating tumours with or without regional LN mets
Stage 4: distant met
What classifies as Kiupel high grade canine cMCT?
- MI >7/ 10hpf
- at least 3 bizzare nuclei in 10 hpf
- at least 3 multinucleation in 10 hpf
- karyomegaly (>10% of nucleus)
What’s the % of normal sized LN that will still be metastatic in canine MCT?
50%
What factor is significantly associated with a HN>0 LN?
primary mass >3cm.
What are some minimum histological margins that did not show recurrence/ metastasis in canine cutaneous MCT?
lateral margins ≥ 10 mm and deep margins ≥ 4 mm.
What’s the accuracy of pre-tx biopsy for canine cutaneous MCT regarding the grade?
Fairly accurate!
overall concordance rate of 96% based on the Patnaik grading system, and an overall concordance rate of 92% based on the Kiupel grading system.
All discrepancies underestimated the grade of the MCT.
In this 2011 study, they found needle core to be the most accurate- but could be due to lower numbers in each case, and there was no statistical significance between the different sampling procedures (wedge, punch, needle core).
What’s the 2 year control rate of stage 0 canine MCT with adjuvant radiation therapy?
85-95% control rate
What’s the utility or re-excision or RT of incomplete/ close margin MCT
Either modality (Sx, RT) can significantly improve survival time compared to no treatment (2930d vs 2194 vs 710). Local recurrence occurred in 13% of the re-excision group, 8% of the radiation therapy group, and 38% of the comparison group.
What’s the prognostic value of removing HN2 & HN3 lymph nodes?
On multivariable analysis, the risk of tumour progression and tumour-related death were 5.47 and 3.61 times higher in the LNS group, respectively (P < 0.001)
Marconato et al 2018.
What’s the false-negative rate for LNs FNA vs Sx?
In one study in 2017:
High proportions of false-negative results were found in mesenteric T-cell lymphoma (22/35, 63%, mainly cats), metastatic sarcoma (8/14, 57%) and metastatic mast cell tumour (15/48, 31%, mainly dogs).
Report data on MCT discrepancies = 10-50%
What’s the recurrence rate for incompletely low/ intermediate grade canine MCT?
10-30%
(but studies still showed increased local recurrence and/or decreased ST in dogs with incompletely removed MCT)
What are the reported the local recurrence rate post surgery for canine MCT?
local recurrence rate ranging from 19% to 35.9% after surgery, regardless of histological margins