Mammary

Question 1

Gemignani, JAVMA, 2018:
Mammary adenocarcinoma in cats
What % of cats had tumors in >1 mammary gland?
What % of cats had lymphatic invasion and what % had vascular invasion?
What % of lymph nodes removed had evidence of metastasis?
What % of cats had evidence of distant metastasis?
Incomplete and narrow margins were reported in what % of unilateral vs bilateral mastectomy cases?
Post-op complication rate?
Factors associated with disease progression?
Benefits of bilateral mastectomy over unilateral mastectomy?
Treatment with adjuvant chemotherapy was protective against death - true or false?

Answer 1

Gemignani, JAVMA, 2018:
33% had tumors in >1 mammary gland
40% had lymphatic invasion and 15% had vascular invasion
44% of lymph nodes removed had evidence of metastasis
0% had distant metastasis
Incomplete and narrow margins were reported in 24% of unilateral vs 10% of bilateral mastectomy cases
Post-op complication rate: 29% (more common with bilateral vs unilateral mastectomy, and more common with single-session bilateral vs staged bilateral mastectomy)
Factors associated with disease progression: unilateral mastectomy, tumor ulceration, lymph node metastasis at the time of surgery, tumors arising in a 4th (inguinal) mammary gland
Benefits of bilateral mastectomy over unilateral mastectomy: improved progression-free interval and MST
True

Question 2

Litterine-Kaufman, JAVMA, 2019:
Mammary masses in dogs
What % of the masses were benign or non-neoplastic?
What % of the masses were not of mammary origin?
Masses from which mammary glands had a lower prevalence of malignancy compared to the other glands?

Answer 2

Litterine-Kaufman, JAVMA, 2019:
85% were benign or non-neoplastic
5% were not of mammary origin
Masses from the 4th (caudal abdominal) mammary gland had a lower prevalence of malignancy than the other mammary glands combined

Question 3

Evans
Complications with Mastectomy
JAVMA 2021

Answer 3

Complications 17%

Increased odds with:
~Increased BW
~Bilateral mastectomy
~No PO antibiotics in chain mastectomy

Decreased odds
~concurrent OVE/OHE

Question 4

Litterine-Kaufman
Mammary glands of dogs
JAVMA 2019

Answer 4

85% non-neoplastic
15% neoplastic

Prevalence of malignancy
less in 4th

Not related to malignancy
~Age
~reproductive status
~quantity of masses

Question 5

Gemignani
Feline mammary adenocarcinoma
JAVMA 2018

Answer 5

Complications
~unilateral 20%
~staged bilateral 36% (sign)
~Single-session bilateral 41% (sign)

Median progression-free
~bilateral 542 d (*sign)
~unilateral 289 d

Factors for progression
~unilateral mastectomy
~tumor ulceration
~LN mets (*sign)
~4th mammary gland

Chemo decreased disease-related deaths

Question 6

Gemignani et al JAVMA 2018
What are significant risk factors for disease progression in cats with mammary adenocarcinoma?

Answer 6

1. unilateral mastectomy (vs bilateral)
2. tumor ulceration
3. lymph node metastasis
4. tumors arising from the 4th mammary gland

Question 7

Gemignani et al JAVMA 2018
What are risk factors for death due to mammary adenocarcinoma in cats?

Answer 7

lymph node metastasis
Development of regional of distant metastasis

Question 8

Litterine-Kaufman et a JAVMA 2019
What percentage of canine mammary gland region masses are benign? Malignant?

Answer 8

85% benign
15% malignant

Question 9

Litterine-Kaufman et a JAVMA 2019
What factors were not associated with the presence of malignant canine mammary masses?

Answer 9

age
reproductive status
single vs multiple masses
presence of mass in 4th mammary gland