Sa Medicine -- Mammary Cancer

Front 1

What is the most common tumor in female dogs?

Back 1

--mammary tumor

--50 -70% of all tumors in female dogs

Front 2

Mean age of dogs with malignant tumors? Benign?

Back 2

--malignant: 9-11y

--benign: 7-9y

Front 3

Do small or large breed dogs have higher risk of mammary cancer?

Back 3

--small breed dogs

Front 4

Dogs spayed before first estrus cycle have ___% chance of mammary cancer.

Back 4

-- <0.5%

Front 5

Dogs spayed before second estrus cycle have ___% chance of mammary cancer.

Back 5

--8% chance

Front 6

Dogs spayed before third estrus cycle have ___% chance of mammary cancer.

Back 6

--26%

Front 7

After third estrus cycle, any benefit of spay?

Back 7

--no preventative benefit of spay beyond 3rd

Front 8

Exposure to pharmacologic hormones (progestins and estrogens) increases risk of mammary cancer in dogs. T/F?

Back 8

--true

--2.3x inc. risk

Front 9

Why is it a good idea to remove benign mammary tumors?

Back 9

--they progress to malignant tumors in time

>> accumulation of mutations, etc.

Front 10

Progression of benign mammary tumors to malignant ones?

Back 10

--normal ductal lumen

--benign proliferation

--atypical hyperplasia

--ductal carcinoma in situ

--invasive carcinoma

Front 11

How does estrogen promote the development of mammary cancer?

Back 11

--estrogen and progesterone inc. epithelial cell proliferation

--estrogen is mutagenic to epithelial cell DNA

--progesterone and estrogen increase expression of growth hormone receptors and GH secretion

Front 12

Hormonal _____ is associated with poorly differentiated/malignant tumors.

Back 12

--hormonal independency

>> loss of receptors increases aggression

Front 13

Which are more likely to have hormone receptor positive tumors: dogs that are intact, younger, and in estrus, or dogs that are spayed, older, and in anestrus?

Back 13

--dogs that are intact, younger, and in estrus

Front 14

Risk assoc. with estrogen therapy in dogs?

Back 14

--bone marrow suppression

--delayed growth plate closure

Front 15

What is recommended to all dogs with estrogen-receptor positive tumors?

Back 15

--hormone inhibition therapy

Front 16

What are BRCA1 and BRCA2? Dog equivalent?

Back 16

--gene mutations that are assoc. with an 85% risk of breast cancer in humans

--germline mutations in BRCA1 and BRCA2 were found to be assoc. with inc. risk in English Springer Spaniels

Front 17

Risk factors for mammary tumors in dogs?

Back 17

--hormone exposure (late spay or intact)

--BRCA1 or BRCA2

--obesity

Front 18

Why is obesity a risk factor for mammary cancer?

Back 18

--adipose tissue produces estrogen

--leptin increases estrogen binding

--obesity assoc. with dec. sex hormone binding globulins >> inc. serum free estrogen levels

Front 19

Which mammary glands are most commonly affected?

Back 19

--4th and 5th (70%)

Front 20

Intact females are more likely to have?

Back 20

--more likely to have more than one mass on diagnosis

Front 21

What is inflammatory mammary carcinoma?

Back 21

--ulcerative mass with poor demarcation and a warm, irritated area

--pain, anorexia, febrile, weight loss, weakeness

--often assoc. w/ pelvic limb edema and lameness

Front 22

Distant metastatic sites of mammary cancer?

Back 22

--lymph nodes, liver, lungs, bone

Front 23

What is the gold standard for mammary tumor diagnosis?

Back 23

--biopsy & histology

>> cytology is 90% but histology is best

Front 24

With mammary tumors, it is important to do what?

Back 24

--FNA of regional lymph nodes, even if normal size

Front 25

TNM staging of mammary tumors?

Back 25

--stage 1: T1 <3cm, N0, M0

--stage 2: T2 3-5cm, N0, M0

--stage 3: T3 >5cm, N0, M0

--stage 4: T1-3, N1, M0

--stage 5: T1-3, N0-1, M1

Front 26

Treatment of mammary tumors?

Back 26

--surgical excision for benign and malignant masses!

Front 27

Simple mastectomy and radical mastectomy have similar MST in dogs. T/F?

Back 27

--true

Front 28

Contraindications for mammary tumor surgery?

Back 28

--metastatic disease

--inflammatory carcinoma

Front 29

What is a local mastectomy?

Back 29

-- removal of a single mammary gland, >1cm, moveable/fixed masses

Front 30

What is a regional mastectomy?

Back 30

--removal of > or = mammary glands and assoc. LNs

Front 31

What is a unilateral mastectomy? Indication?

Back 31

--removal of entire mammary chain

>> indicated when mammary masses involve > or = ipsilateral mammary glands

Front 32

What is a bilateral mastectomy? Indication?

Back 32

--remove both mammary chains

--multiple and bilateral mammary glands involved

Front 33

Chemotherapy for mammary carcinoma? Used how? MST?

Back 33

-- 5-fluoroucil + cyclophosphamide

--used after surgical resection

--MST 24mo v. 6 mo

Front 34

Best treatment for dogs with inflammatory mammary carcinoma?

Back 34

--piroxicam (NSAID)
>> tumors are Cox-2 expressing

--radiation therapy

Front 35

Treatment for metastatic bone lesions?

Back 35

--bisphosphonates (pamidrinate/zoladronate)

AND

--palliative radiation

Front 36

Should hormone therapy (e.g. tamoxifen) be used in dogs?

Back 36

--no

--adverse effects: vulvar swelling, vaginal discharge, incontinence, UTI, stump pyometra, signs of estrous

Front 37

Ovariohysterectomy performed at the time of mammary tumor excision reduced risk of new tumors by ___%.

Back 37

--50%

Front 38

Poor prognostic factors for mammary tumors? Which histologic grades and types are worst?

Back 38

--anaplastic carcinoma is most malignant

--sarcomas poor prognosis compared to carcinomas

--invasion, intravascular growth

--decreased expression of estrogen receptors

--metastatic disease

Front 39

Better prognostic factors for mammary tumors?

Back 39

--tumor size <3cm
>> better prognosis and lower recurrence
--lower stage better prognosis

Front 40

Which breed is predisposed to mammary tumors?

Back 40

--siamese cats

Front 41

Intact cats have ___x increased risk of mammary cancer.

Back 41

7x

Front 42

Most mammary tumors in cats are _____ ______ ______. This means they are more aggressive.

Back 42

--not hormone responsive

>> lack estrogen and progesterone receptors

Front 43

If spayed before 6 mo, cats have a ___% reduced risk of mammary cancer.

Back 43

91%

Front 44

Treatment of cats with _____ increases risk of mammary tumor malignancy.

Back 44

--progesterone

Front 45

Majority of cats have only one mammary tumor. T/F?

Back 45

--false

Front 46

Which glands are more commonly affected in cats?

Back 46

--cranial glands

Front 47

Large masses in cats may have?

Back 47

--ulceration

--inflammation

--infection

Front 48

Staging in cats?

Back 48

--CBC/chem/UA

--chest rads

--FNA of mass and LNs

--abdominal US and CT

--biopsy

Front 49

TNM Staging: T in cats?

Back 49

T1: <2cm

T2: 2-3cm

T3: >3cm

Front 50

TNM Staging in cats?

Back 50

--stage 1: T1 <2cm, N0, M0
--stage 2: T2 2-3cm, N0, M0
--stage 3: T3 >3cm, N0/N1, M0
T1/T2, N1, M0
--stage 4: any T, any N, M1

Front 51

What is mammary hyperplasia? Go away when?

Back 51

--proliferation of interlobular ducts and stromal cells

--hormonally-induced in progestin-treated female and male cats

--go away when spayed

Front 52

Prognostic indicators in cats?

Back 52

--involvement of lymph or blood vv.

--bigger masses, shorter MST
--LN invovlement

--pure breed cats (esp. siamese) have worst prognosis

Front 53

Treatment of mammary tumors in cats?

Back 53

--chain resection with single mass

--bilateral chain mastectomy if both sides

--en bloc resections if fixed masses involve mm.

Front 54

MST for surgery + chemo?

Back 54

--2000 days (sx + chemo) vs. 414 days (sx only)

Front 55

Chemo drugs for mammary tumor?

Back 55

--doxorubicin + cyclophosphamide