Oncology

Question 1

What is the reported overall survival time for tonsillar carcinomas in dogs, all treatment modalities combined (surgery, chemotherapy (conventional, tyrosine kinase inhibitors or metronomic chemotherapy), radiotherapy, nonsteroidal anti- inflammatory drugs (NSAIDs) or a combination of these) ?

Answer 1

Overall survival time was 126 days (95% confidence interval [CI], 88-164). Significantly longer survival was seen in dogs without evidence of metastatic disease (median survival time, 381 days; 95% CI, 116-646).

Ref : JVIM dec 2023, Treggiari, Tonsillar carcinoma in dogs: Treatment outcome and potential prognostic factors in 123 cases

Question 2

Between primary tonsillar carcinoma and non-tonsillar oral carcinomas in dogs, which one has the higher potential for local metastatic disease ?

Answer 2

Primary tonsillar carcinoma is reported rarely in dogs when compared to non-tonsillar oral carcinomas and has a higher potential for local metastatic disease (up to 73%), when compared to oral carcinomas in other locations. Metastatic disease usually involves regional lymph nodes (mandibular, retropharyngeal, cervical) and lungs.

Ref : Mas A, Blackwood L, Cripps P, et al. Canine tonsillar squamous cell carcinoma—a multi-centre retrospective review of 44 clinical cases. J Small Anim Pract. 2011;52:359-364.

JVIM dec 2023, Treggiari, Tonsillar carcinoma in dogs: Treatment outcome and potential prognostic factors in 123 cases

Question 3

Which factors are positive prognostic factors for dogs with primary tonsillar carcinoma ?

Answer 3

Absence of metastatic disease, absence of clinicals signs at presentation, surgery (tonsillectomy), use of adjuvant chemotherapy and use of NSAIDs.

Ref : JVIM dec 2023, Treggiari, Tonsillar carcinoma in dogs: Treatment outcome and potential prognostic factors in 123 cases

Question 4

What is the use of telomerase in cancer (and germinal) cells?

Answer 4

It allows replication of telomeres and increase lifespan of cells

Question 5

What is the purpose of mesna administration with cyclophosphamide?

Answer 5

Reduce risks of cystitis (binding in the urine)

Question 6

What is the purpose of the administration of dexrazoxane with Doxorubicin?

Answer 6

Reduce cardiotoxicity and lesions after extravasation

Question 7

What is the difference between overal response rate and clinical benefit?

Answer 7

Clinical benefit also includes stable disease

Question 8

True or false: cross resistance in chemotherapy does not occur with alkylating agents?

Answer 8

True

Question 9

True or false: definitive intent RT protocols usually consist of large number or low dose fractions with more acute side effects and less late side effects

Answer 9

True

Question 10

True or false: palliative intent RT protocols usually consist of small number of high dose fractions with less acute side effects and more late side effects

Answer 10

True

Question 11

How does radiation interact with tissue?

Answer 11

A photon removes an orbiting electron from an atome (ionization) and a second photon is emitted from this action. The electron and secondary photon can interact with the tissue. The electrons emitted damage the tissues.

Question 12

True or false: low energy X-ray (such as brachytherapy) deposit the energy at or just below the skin surface

Answer 12

True (and high energy deposit most at greater depth - “skin sparing”)

Question 13

What are the 4R that determine response to RT?

Answer 13

Repair (intensity of damage)
Redistribution (G1 and mid-S phase cells are more resistant, cells are redistributed into synchron phases)
Repopulation (cellular division)
Reoxygenation (O2 increases RT damages)

Question 14

Of what is predominantly dependent acute toxicity after RT?

Answer 14

The total dose of radiation (higher dose, higher risk) but also shorter time of administration and higher fraction size

Question 15

What type of tissue is mainly affected by acute toxicity of RT? And late toxicity?

Answer 15

Acute: rapidly renewing tissue
Late: slowly proliferating tissue

Question 16

On what depends the likelihood of late toxicity or RT?

Answer 16

The fraction size (the higher, the higher the risk)

Question 17

Do dogs who have Mast cell tumor with KIT mutation respond better to TKI treatment ?

Answer 17

Yes

Question 18

Almost all myelosuppressive chemotherapeutics have a nadir at 6-8 days, except 2 molecules, which ones?

Answer 18

Lomustine in cats: 7-28 days
Carboplatine: 14 days in dogs, 25 days in cats

Question 19

True or false: coadministration of l-asparaginase and vincristine may result in more severe neutropenia

Answer 19

True

Question 20

To which chemotherapeutics MDR-1 dogs are more susceptible?

Answer 20

Vincristine, vinblastine, Doxorubicin…

Question 21

Which chemotherapeutics more frequently produce thrombocytopenia?

Answer 21

Carboplatine, lomustine, Doxorubicin, melphalan…

Question 22

What chemotherapeutics extravasation cause the more damage?

Answer 22

Vincristine, vinblastine, doxorubicine…

Question 23

True or false: Vincristine via a neurotoxic effect may induce iléus in dogs and cats

Answer 23

True

Question 24

What is the impact of liposomal form of Doxorubicin?

Answer 24

Reduced cardiotoxicity but new dermatologic toxicity

Question 25

True or false: vincristine is mainly eliminated via biliary excretion and should be avoided or dose reduced in case of marked cholestasis

Answer 25

True

Question 26

True or false: Vincristine risks to be more neurotoxic in case of MDR-1 dogs

Answer 26

True

Question 27

What is acrolein?

Answer 27

An inactive metabolite of cyclophosphamide that is a direct urothelial irritant

Question 28

What can reduce cystitis secondary to cyclophosphamide ?

Answer 28

Mesna or furosemide administration

Question 29

What type of hypersensitivity reaction may be seen with l-asparaginase? And Doxorubicin?

Answer 29

L-asparaginase : type I (IgE) Doxorubicin: histamine release from mast cells with rapid administration (non IgE)

Question 30

Why is cisplatin contraindicated in cats?

Answer 30

Fatal pulmonary edema

Question 31

What may result from high cumulative doses of lomustine in cats?

Answer 31

Pulmonary hypertension and fibrosis

Question 32

True or false: CSF cytology is more useful for the diagnosis of CNS lymphoma in dogs than in cats

Answer 32

True due to the extradural form preponderance in cats

Question 33

In cats suspected of CNS lymphoma what other 2 sites are frequently involved?

Answer 33

Kidneys and bone marrow

Question 34

What chemotherapeutics may act on a CNS lymphoma?

Answer 34

L-asparaginase, cytosine arabinoside and corticosteroids

Question 35

Name prognostic factors of lymphoma in dogs

Answer 35

Immunophenotype, clinical substage, histopathology, anemia, corticosteroid treatment, cranial mediastinal lymphadenopathy

Question 36

True or false: approximately 10% of acute lymphoblastic leukemia are aleukemic leukemia (absence of peripheral circulation)

Answer 36

True

Question 37

Of leukemia and lymphoma, which one should be CD34+

Answer 37

Leukemia

Question 38

Name myeloma related disorders (4)

Answer 38

Multiple myeloma Extramedullary plasmacytoma IgM macroglobulinemia (Waldenstrom) Ig secreting lymphoma/leukemia

Question 39

True or false: in myeloma related disorders, hyper viscosity syndrome is more frequent with IgM macroglobulinemia

Answer 39

True, due to its high molecular weight

Question 40

What is the diagnosis of multiple myeloma?

Answer 40

Bone marrow plasmacytosis, M-component in the urine or blood and bone/visceral lesion (if the last is absent, progressive increase in M-component should be assessed)

Question 41

What is the predominant M-component in multiple myeloma in dogs? And in cats?

Answer 41

Dogs: IgA (and IgG) Cats: IgG

Question 42

What are two main forms of papilloma associated with age in dogs?

Answer 42

Cutaneous form in older dogs Oral papillomatosis in young or immunocompromised dogs

Question 43

In what tumor may rarely progress papilloma in dogs?

Answer 43

Carcinoma

Question 44

To what might be viral papillomas precursors in cats?

Answer 44

Squamous cell carcinoma

Question 45

To what tumor, sun damage may be a predisposition in dogs and cats?

Answer 45

Cutaneous squamous cell carcinoma

Question 46

What is Bowen disease in cats?

Answer 46

Multicentric in situ SCC, might be due to papillomavirus

Question 47

What is generally the behaviour of melanoma from a mucocutaneous junction? And haired skin?

Answer 47

Mucocutaneous: malignant (including digital) Haired skin: benign

Question 48

True or false: It is difficult to predict the biological behaviour of melanoma in cats based on the mitotic index

Answer 48

True

Question 49

What is the target of the vaccine against melanoma in dogs?

Answer 49

Tyrosinase, an enzyme necessary for the synthesis of melanin

Question 50

What are the IHC markers of GIST?

Answer 50

GIST: KIT +, DOG1 +, vimentin + Leiomyoma/leiomyosarcoma: SMA +

Question 51

True or false: chronic UV light exposure has been associated with dermal hemangiosarcoma along the ventral abdomen or conjunctive

Answer 51

True

Question 52

Does sterilisation have an impact on hemangiosarcoma in dogs?

Answer 52

Yes, female neutered seem overrepresented

Question 53

What biomarker may be useful for hemangiosarcoma?

Answer 53

Collagène XXVII

Question 54

What are the two most common sites of osteosarcoma in dogs?

Answer 54

Proximal humerus and distal radius

Question 55

What are the two main localisation of feline osteosarcoma?

Answer 55

Proximal humerus and digits

Question 56

Brachycephalic breeds are predisposed to high grade or low grade mastocytomas ?

Answer 56

Low grade

Question 57

What coloration and what marker may be useful to see mast cells?

Answer 57

Toluidine blue and CD117

Question 58

What diseases are associated with Langerhans cells?

Answer 58

Histiocytoma, Cutaneous Langerhans cell histiocytosis (dog) Pulmonary Langerhans cell histiocytosis (cats

Question 59

What influences the differentiation of monocytes into macrophages ? And dendritic cells?

Answer 59

M-CSF --> Macrophages GM-CSF --> dendritic cells etc ..

Question 60

What are the cell markers of Langerhans cells?

Answer 60

E-cadherin, CD1a, CD11c/CD18

Question 61

What are the diseases associated with dendritic cells?

Answer 61

Cutaneous and systemic histiocytosis, histiocytic sarcoma and feline progressive histiocytosis

Question 62

What are the cell markers of dendritic cells?

Answer 62

CD1a, CD11c/CD18 and for reactive histiocytosis CD4 and CD90

Question 63

What are the cells of hemophagocytic histiocytic sarcoma and what are the markers?

Answer 63

Macrophages : faible CD1a et CD11d/CD18

Question 64

True or false: malignant mammary tumors are rare in dogs of <5 years old

Answer 64

True

Question 65

True or false: obesity and high fat diets have been linked to increased risk of mammary tumor in dogs

Answer 65

True (higher grade and diagnosed at younger age)

Question 66

What are inflammatory mammary carcinomas?

Answer 66

Rapidly growing tumors with signs of pain, inflammation +/- edema of extremities with a bad prognosis (surgery is not indicated in this case)

Question 67

What are the three "stop" codon?

Answer 67

TAG, TGA, TAA

Question 68

Which class of chemotherapeutics may have cross-resistances ?

Answer 68

Antitumor antibiotics (ex: Doxorubicin) and mitotic inhibitors (ex: vinca alkaloids)

Question 69

Which class of chemotherapeutics are substrate for the MDR pump (p-gp)?

Answer 69

Antitumor antibiotics (ex: Doxorubicin) and mitotic inhibitors (ex: vinca alkaloids)

Question 70

Which chemotherapeutics are the most myelosuppressives ?

Answer 70

Doxorubicine, mitoxantrone, vinblastine, vinorelbine, lomustine, cyclophosphamide, carboplatine

Question 71

In which cell cycle phases are cells most sensitive to radiation therapy?

Answer 71

G2 and M

Question 72

What is the main side effect of rabacfosadine in dogs ?

Answer 72

Dermatologic toxicosis (pruritus, erythema and alopecia)

Question 73

Which vitamin can lower the risks of palmar-plantar erythrodysesthesia in dogs administered IV liposomal Doxorubicin ?

Answer 73

Pyridoxine (vitamin B6)

Question 74

Which chemotherapeutic may induce fatal neurotoxicosis in cats ?

Answer 74

5-FU

Question 75

What are the risk factors for canine dermal SCC?

Answer 75

Thin, non pigmented skin and exposure to sun

Question 76

Which vaccines are associated with feline injection site fibrosarcoma?

Answer 76

Rabies and FeLV vaccines

Question 77

What 3 markers are used for IHC to differentiate between GIST and leiomyosarcoma?

Answer 77

GIST: (c-kit)CD117+, DOG1+, SMA+/- Leiomyosarcoma: CD117-, DOG1-, SMA+

Question 78

What is the main drawback of stereotactic radiotherapy in dogs with osteosarcoma?

Answer 78

The high risk of pathological fracture

Question 79

What has been associated with periarticular histiocytic sarcome ?

Answer 79

Previous joint disease/cranial cruciate ligament rupture

Question 80

Between dogs and cats, which one most frequently has solitary mammary gland tumor ?

Answer 80

Cats

Question 81

What mast cell tumor localisation has the worst outcome?

Answer 81

Scrotal/preputial