Oncology - STS, HS, Mammary Flashcards
What are soft tissue sarcomas?
Mesenchymal tumors/spindle cell tumors - it is an umbrella term
What tumors are soft tissue sarcomas?
Fibrosarcoma, peripheral nerve sheath tumor, myxosarcoma, liposarcoma, rhabdomyosarcoma, synovial cell sarcoma, and lymphangiosarcomas
Soft tissue sarcomas are typically solitary/in multiples.
solitary
What age of dogs and cats typically get soft tissue sarcomas?
older dogs and cats
Where else, aside from the skin, can soft tissue sarcomas be seen?
GI tract, liver, and bladder possible
What is the behavior of STS?
slow growing/insidious onset
STS are __________.
a. not encapsulated
b. pseudoencapsulated
c. encapsulated
b. pseudoencapsulated
What grade of STS are more likely to recur and metastasize?
Grade III
What size STS generally have a poor response to chemo and/or radiation?
Bulky tumors - >5cm
Is an FNA or a biopsy preferred for STS diagnosis?
biopsy
What type of biopsy is preferred for STS diagnosis?
incisional - can be misleading
How do you need to position your biopsy for STS?
Position so that the biopsy tract is removed with surgery
What is staging for STS based on?
Minimum database, FNA local lymph node, 3 view chest rads and CT scan for surgical planning
What makes STS tumors especially difficult to excise?
They have spindles that can spread out from the tumor
What is grading of STS based on?
differentiation, mitosis, and necrosis
What treatment can be done for STS?
Wide surgery, +/- radiation therapy, +/- chemotherapy
What margins do you want for STS?
3cm lateral and 1 fascial plane
What may make it difficult to get complete excision for STS?
Less likely if >5 cm
Deep location
Invasive
Can STS recur after surgery?
Yes, the potential for recurrence is greater with a greater grade
If you chose not to do wide therapy for STS, what are the other options?
Amputation/hemipelvectomy or marginal excision with radiation therapy
When you take a STS out, what do you want to do before placing it into formalin?
pin it out and ink to help prevent shrinkage in formalin
What type of radiation do you want to use with STS if you got marginal excision?
Definitive radiation
Stereotactic doesn’t seem to work as well
What side effects are associated with definitive radiation for STS?
Acute skin effects and a long term potential for secondary tumors
What is the chemotherapy agent of choice for STS? When is it indicated?
Doxorubicin
Indicated for grade III STS
What is the average time to metastatic disease development from STS diagnosis?
1 year
What are the negative prognostic factors for recurrence of STS?
Large tumor size, incomplete excision, and high grade
What are the negative prognostic factors for metastatic disease of STS?
Grade, necrosis, mitotic index, and local regrowth
What is the MST for dogs with a grade I STS?
48 months
What is the MST for dogs with a grade II STS?
17 months
What is the MST for dogs with a grade III STS?
7.8 months
Can STS be cured?
Yes, with proper planning some can be cured
What type of neoplasia is a cutaneous histiocytoma?
A benign skin tumor that is a solitary lesion with rapid growth, but has spontaneous regression in 1-2 months
Where can histiocytic sarcomas (HS) be located?
They can be localized anywhere in the body or can be disseminated
What is the origin of hemophagocytic HS?
macrophage origin
What do hemophagocytic HS do?
Eat the RBCs
How are HS diagnosed?
Cytology or biopsy
Definitive diagnosis can be difficult
What may be needed for a definitive diagnosis for HS?
ICC/IHC
CD18 stain
What is needed for staging of HS?
minimum database, chest rads, abdominal ultrasound
How is the disseminated form for HS treated?
It is rapidly fatal and difficult to treat
How is localized HS treated?
Surgery if you can. radiation therapy, and chemotherapy
What is the treatment of choice for HS?
CCNU/lomustine
What are the most common tumors of intact female dogs?
mammary tumors
What percentage of canine mammary tumors are considered malignant? How many of them metastasize?
50% are malignant - 50% of those metastasize
What are the 3 major factors important in development of canine mammary tumors?
Age, hormonal exposure, and breed
What age is malignant canine mammary tumors associated with?
middle-older age
During what time in life is obesity especially an issue for canine mammary tumors?
9-12 months of life because adipose tissue produces estrogens and is inflammatory
What is field carcinogenesis?
when the entire mammary chain is exposed to estrogen
What mammary glands most commonly develop tumors first?
the caudal two glands
What is needed for diagnosis of canine mammary tumors?
Minimum database, FNA, chest x-rays, FNA to rule out other tumor types, and biopsy
What are the most common mammary tumors that we find?
carcinomas - malignant epithelial tumors
What are the types of malignant epithelial tumors that can be a canine mammary tumor?
In order from least to most aggressive - carcinoma in situ, complex carcinoma, simple tubulopapillary carcinoma, simple solid carcinoma, and simple anaplastic carcinoma
What is grading for canine mammary tumors based on?
tubule formation, nuclear pleomorphism, and mitotic index
What are some prognostic factors for canine mammary tumors?
Tumor size, differentiation, histologic classification, detection off lymphatic vessel invasion (BAD), and regional LN metastasis and distant metastasis
What are the treatment options for canine mammary tumors?
surgery, radiation therapy, and chemotherapy
What are the types of surgery that can be done for canine mammary tumors?
Simple lumpectomy, mastectomy, regional mastectomy, chain mastectomy, and bilateral mastectomies
What surgery should you start with first in dogs with canine mammary tumors?
conservative surgery
What surgery is recommended for dogs with one mammary tumor?
Surgery to completely remove the tumor
What surgery is recommended for dogs with multiple mammary tumors?
regional mastectomy or unilateral chain mastectomy
What surgery is recommended for intact dogs with multiple tumors?
unilateral or bilateral mastectomies
An OHE is recommended for intact females with mammary tumors. When should it be done?
It should be done before removal of the mammary glands
Why are inflammatory canine carcinomas in the mammary glands so bad?
They are highly metastatic and have local coagulopathies
When should radiation therapy be considered for canine mammary tumors?
if there are incompletely removed tumors
When is chemotherapy indicated for canine mammary tumors?
If the tumor is >3cm, if it has metastasized, or if it is inflammatory or an osteosarcoma
What chemotherapy agent is recommended for canine mammary tumors?
Doxorubicin or carboplatin
What is the prognosis for canine mammary tumors?
Overall great, but a worse prognosis is associated with high grade, inflammatory, or OSA
What are the three risk factors for feline mammary tumors?
Age, hormonal exposure, and breed
___% of cats have more than one mammary tumor.
60%
What age is associated with diagnosing mammary tumors in cats?
older cats
What is the malignancy percentage and metastasis percentage for feline mammary tumors?
85-95% are malignant and 90% are metastatic
What is needed for staging of feline mammary tumors?
minimum database, chest rads, AUS, and FNA of LN
What benign tumors can be feline mammary tumors?
Very rare - adenomas, ductal adenoma, and fibroadenoma
What malignant tumors can be feline mammary tumors?
simple carcinoma or other types of carcinoma
What are the prognostic factors for feline mammary tumors?
Grade, lymphovascular invasion, positive LN, +/- Siamese, size
What treatment can be done for feline mammary tumors?
surgery, radiation, and chemotherapy
What is the recommended surgical approach for feline mammary tumors?
Chain mastectomy - we need to be aggressive because they are aggressive
IF you do radiation therapy for feline mammary tumors, what type do you do?
palliative
What chemotherapy options are there for feline mammary tumors?
Doxorubicin, mitoxantrone, or carboplatin
When is chemotherapy indicated for feline mammary tumors?
High grade and vascular invasion, >3cm, or if there is LN involvement
Overall, what is the most common type of mammary tumor in dogs and cats?
carcinoma