Hematopoietic Malignancies Part 1 Flashcards
What is lymphoma ?
Lymphoma is a malignant tumor of lymphoid tissue
What is the prevalence of lymphoma?
Makes up 80 % of all hematopoietic tumors
and 1/4 of all canine cancer
Which breeds are predisposed to lymphoma?
Rottweilers, Boxers, Bull mastiffs, Golden Retrievers
Airdale Terriers
What are the 4 most common type of cancer that results in HYPERCALCEMIA
Anal sac adenocarcinoma, myeloma, mammary tumors and lymphoma
What are the clinical signs of canine lymphoma?
generalized painless lymphadenopathy
- others are non-specific unless lesion is affecting the organs
How would you dx canine lymphoma ?
- FNA / Cytology - majority of cases
IF FNA is not diagnostic –> use 2-5 - Biopsy -> Necessary to DETERMINE SUBTYPES through histopathology
- PCR for antigen receptor rearrangements (PARR)
- Flow cytometry
- Immunophenotype
What is a normal lymph node cytology like ?
90% small lymphocytes
10% - other cells
What is a reactive lymph node cytology like ?
75-80% small lymph nodes
20-25% plasma cells
neutrophils and macrophages
When you see that there is >50% large lymphocytes or lymphoblasts, what grade of lymphoma does that indicate?
INTERMEDIATE to HIGH grade lymphoma
What is the advantage of histopathology?
Ability to evaluate the archietecture throughout the ENTIRE NODE
What is the most common B cell lymphoid tumor ?
Diffuse Large B Cell LSA / High Grade B Cell (50%)
What is the most common T cell/NK lymphoid cancer?
Peripheral T cell Lymphoma
What are the three histologic subtypes that have been prognostic
Diffuse Large B cell Lymphoma (high grade)
Peripheral T Cell Lymphoma (high grade)
Indolent T Cell Lymphoma (low grade)
How does PARR work?
Lymphocytes carry unique DNA sequence
With differentiation, there is rearrangement of genes in response to stimuli
- B cells carry Ig
- T cells carry T cell receptor
With neoplastic lymphoid cells - DNA is PERMANENTLY rearranged within the cell - CLONAL/ HOMOGENOUS population
What is immunophenotyping and how is it done?
testing that can discern B cell lymphoid cancer or T cell lymphoid cancer
- immunohistochemistry (on tissue)
- flow cytometry (cells suspended in fluid)
- PCR / PARR for lymphoid cancer (on smears)
- immunocytochemistry (on smears)
Describe the WHO Clinical Staging of Canine Lymphoma
Stage I - affects solitary node
Stage II - affects regional nodes-
Stage III - affects peripheral node
Stage IV - LIVER/SPLEEN/ MEDIASTINUM with/without peripheral nodes
Stage V - other ‘weird’ places : bone marrow or non lymphoid tissues
Substage a: animal does not present with systemic signs
Substage b : animal presents with systemic signs
Hypercalcemia is usually associated with B or T cell lymphoma?
T
What happens if you do not treat a dog with lymphoma?
Develop progressive anorexia, v+, d+
Survival ~ 4-6 weeks
CURES for HIGH GRADE LYMPHOMA are RARE. THERAPY is only PALLIATIVE
FACT
What are the 6 chemotherapeutic drugs that can be used to treat lymphoma ?
Prednisone Doxorubicin Vincristine Cyclophosphamide L-Asparaginase CCNE
Name the 4 criterias for remission
Complete response : normal palpation and imaging
Partial response : >30% reduction
Stable Dz: no partial response and no progressive dz
Progressive Dz: >20% increase
Name the 4 criterias for remission
Complete response : normal palpation and imaging
Partial response : >30% reduction
Stable Dz: no partial response and no progressive dz
Progressive Dz: >20% increase
How do you assess response to therapy?
physical examination - node assessment and measurements… and palpation of spleen
Imaging may be necessary
How do you treat High Grade Lymphoma using a single agent therapy?
- Glucocorticoids - animal will live for another 1-2 months
- Chemo
- Vincristine
- Cyclophosphamide
- L- Aspariginase
- Lomustine / CCNU
- 50% response of 203 .months duration
What is the STRONGEST chemotherapeutuc agent that you can use for High Grade Lymphoma
Doxorubicin
- higher response/longer remission duration of 6-7 months
Why are multiple agents preferred for the treatment of High grade lymphoma
Larger tumor volume = higher rate of mutations
Inherently resistant neoplastic cells are present
Different mechanisms of action of each agent and you can minimize overlapping toxicities –> BETTER RESPONSE
Explain the CHOP based protocol for High Grade LSA
Cyclophosphamide
Hydroxydaunorubicin (Doxorubicin)
Oncovin = Vincristine
Prednisone
- 80-90% response with remission of 9-12 months
When does one begin therapy?
AFTER a confirmation of lymphoma is obtained
Under the many actions of prednisone, a reduction in size of the lesion/ LN is NOT dx for lymphoma or any other cancer.
WORD.
When does one begin therapy?
AFTER a confirmation of lymphoma is obtained
Under the many actions of prednisone, a reduction in size of the lesion/ LN is NOT dx for lymphoma or any other cancer.
WORD.
How does radiation cause cell death
Double stranded breaks in DNA
MULTI AGENT Chemo are typically NOT used for low grade, small cell lymphoma
true
How do you treat low grade, small cell lymphoma ?
Prednisone and/or chlorambucil for those that have signs or internal involvement.
What is the epidemiology of feline LSA ?
Higher risk patients - FeLV, FIV and cats exposed to passive cigarette smoke
- Heritable in Siamese cats - young
What is the prognosis for low grade/small cell lymphoma ?
GREAT. > 90% alive after 1.5 years of dx
What are the three major forms of lymphoma in cats?
Lymphocytic = low grade
Intermediate grade - rare
Lymphoblastic - high grade
What are the three major forms of lymphoma in cats?
Lymphocytic = low grade
How can Lymphoblastic / high grade lymphoma(feline) be diagnosed?
FNA
Where is the most common anatomic location for lymphoma
Gastrointestinal
Gastrointestinal lymphoma is associated with _____ infection.
Helicobacter
How do you dx feline lymphoma?
Radiographs
Abdominal U/S
How do you dx feline lymphoma?
Radiographs
Abdominal U/S
Endoscopy
Surgical Exploratory –> BIOPSY !
What is Lymphocytic GI lymphoma?
Small mature lymphocytes
- can be a challenge to differentiate from IBD
Differentiate Lymphocytic GI lymphoma and IBD
IBD - mixed population
Lymphoma - monoclonal population of T cells
Multi agent chemo is NOT necessary for Feline LymphoCYTIC Lymphoma. How do you tx it then?
FACT
Prednisone and Chlorambucil
How would you treat LymphoBLASTIC Lymphoma ?
COP or CHOP protocol
In cats, doxorubicin alone is ineffective
