Chapter 22 - Oral Tumors Flashcards
Oral cancer accounts for what percentage of all cancer in dogs and cats?
6 to 7% - dogs, 4th most common cancer overall
3% - cats
Oropharyngeal cancer is how many times more common in dogs than cats? Is there a sex predisposition in dogs?
2.6x more common in male dogs
Male sex predisposition for OMM and tonsillar SCC
Whar are the most common malignant tumors in the oral cavity in dogs and cats?
Dogs:
- Melanoma
- Squamous cell carcinoma
- Fibrosarcoma
Cats:
- Squamous cell carcinoma
- Fibrosarcoma - 13% of al oral tumors
In what size of dogs is malignant melanoma more common?
Small breeds
How many of oral malignant melanomas are amelanotic melanomas?
1/3
Which IHC markers can differentiate an amelanotic melanoma from other oral tumors (4)?
Melan A, S100, PNL2, tyrosinase (TRP1/2)
93% sensitive
100% specific
What is the metastatic rate of oral malignant melanomas?
To which places does it most commonly metastasize?
Metastatic rate is dependent on what (3)?
Death due to pulmonary metastasis occurs in what % of dogs?
80%
RegionalLN (75%), lungs (90%)
Site, size, WHO stage
Up to 70%
What can increase the risk of SCC development in cats (4)?
Flea collars 5x
Canned food 3x
Canned tuna 4.7x
Household smoke 2.5x
What gene is thought to be possibly mutated in cats with oral SCC that are exposed to environmental smoke?
p53
What paraneoplastic syndrome has been associated with cats with oral SCC?
Hypercalcemia - PTH-rp mediated
What is the metastatic rate to LN and lungs in cats with oral SCC?
30% mandibular LN mets
10% pulmonary mets
Rare and infrequent
What is the metastatic rate for dogs with non-tonsillar vs tonsillar/tongue oral SCC? Most common metastatic site?
Non-tonsillar: 20%
Tonsillar/tongue: 70%
What percentage of dogs with oral SCC have bone involvement?
80%
What percentage of dogs with oral malignant melanoma have bone involvement?
90%
What percentage of dogs with oral fibrosarcoma have bone involvement?
60-70%
What percentage of dogs with oral acanthomatous ameloblastomas have bone involvement?
80-100%
How commonly do cats with oral SCC and fibrosarcoma have bone involvement?
Common
Oral fibrosarcoma in dogs tends to occur in what size, breed, and age?
Large sized
Goldens and Labradors; Goldens especially for hi-low FSA
7.3 - 8.6 (young adults)
Most common location in dogs with oral SCC?
Rostral
Most common location for oral high-low fibrosarcoma?
Hard palate and maxillary arcade - between the canine and carnassial teeth
What is the treatment of choice for biopsy results that suggest fibromas or low grade fibrosarcoma?
Aggressive surgery and/or RT
What is the metastatic rate of oral fibrosarcomas in dogs and where does it metastasize? Hi-low FSA met rate?
FSA - up to 30% met rate
Lungs and regional LNs (equally)
High low FSA 12-20% met rate
What are epulides and what were the three types? What is the new term for these lesions?
Benign gingival proliferations arising from the periodontal ligament that appear similar to gingival hyperplasia
Old terminology: epulides
- Acanthomatous
- Fibromatous
- Ossifying
New terminology:
Acanthomatous ameloblastoma
Peripheral odontogenic fibroma = included ossifying and firbous epulides
What are peripheral odontogenic fibromas?
___% of feline peripheral odontogenic fibromas occur in cats less than ___ yrs.
What is the mean age at presentation for dogs?
Metastatic rate?
Slow growing, firm masses that are usually covered by intact epithelium
50% occur in cats less than 3 yrs
Dogs - 8 to 9 years
0%
Most common site for peripheral odontogenic fibromas?
Maxilla, rostral to the third premolar teeth
Recurrence rate in dogs?
3-yr PFS with RT in dogs?
0-17% (even if bone not removed)
86%
What dog breeds (2) are predisposed to acanthomatous ameloblastoma development?
What is the site of predilection?
Do they metastasize?
Shetland Sheepdog and Old English sheepdogs
7 to 10 years
Rostral mandible
Out of the epulides, this is the ONLY ONE that invades bone in 80-100% of cases
0% metastatic rate
What paraneoplastic syndrome has been associated in a cat ith gingival vascular hamartroma?
Hyperglycemia
In px with oral tumors, bone lysis is not radiographically evident until ___ % or more of the cortex is destroyed.
40%
Except for _____, the majority of oral tumors invade the bone.
Peripheral odontogenic fibromas
What are the minimum margins needed for malignant oral tumors in dogs?What about cats?
2cm - dogs
>2cm in cats because of high chance of recurrence with SCC
What are the most common intraoperative and post operative complications of oral tumors when treated with sx?
Intraoperative - blood loss and hypotension
Post operative - incisional dehisence, epistaxis, increased salivation, mandibular drift and malocclusion, difficulty prehending food
Are enteral tubes recommended for dogs and cats after oral surgery?
Only for cats with any type of mandibulectomy because eating can be difficult for 2 to 4 months following surgery
What oral tumors are known to be responsive to RT (3)?
Malignant melanoma
Canine oral SCC
Acanthomatous ameloblastoma
What oral tumors are considered to be RT resistant?
Feline SCC
Fibrosarcoma
What radiosensitizers have been used in cats (3) with oral SCC and dogs (1) with oral melanoma?
Cats - etanidazole, gemcitabine (not recommended because of significant hematologic and local tissue toxicities)
Dogs - platinum drugs
Late complications in oral tumors treated with full fractionation RT occur in less than ___% of the cases.
<5%
For which oral tumors is chemotherapy potentially indicated (2)?
Oral melanoma in dogs
Tonsillar SCC in dogs and cats
Bulky dz, metastatic dz present
ORR of piroxicam in dogs with oral SCC?
17% (1 CR, 2 PR)
ORR and MST in dogs with oral SCC when treated with piroxicam and cisplatin? Nephrotoxicity?
ORR of piroxicam and carboplatin?
Piroxicam and cisplatin:
56% ORR
MST 8m
41% nephrotoxicity
Piroxicam and carbo:
ORR 57%
Sustained in all dogs at median follow up of 534d
Palladia ORR and clinical benefit in dogs with oral SCC?
ORR 75%
Clinical benefit 88%
Recently, ___ was shown to decrease SCC growth in vitro in tumors that over-expressed ___.
YM 155 (a survivin inhibitor) Survivin
Which oral tumor has an unacceptable recurrance rate despite complete resection and needs to be addressed with wider resections or other adjuvant therapies such as RT?
Oral fibrosarcomas
With surgery for oral melanomas, the disease is usually controlled in ___% of the cases.
75%
Most common cause of death in dogs with OMM?Time to metastasis?
Metastasis
10m
What factors affect prognosis in dogs with oral melanoma when treated with sx (3)?
Tumor size: <2cm vs >2cm
Stage - mets vs no mets
Ability of the first sx to achieve local control
What is the reported ORR and MST of hypofractionated RT in cats with OMM?
60% ORR
MST 146 days(4.8m)
What is the MST for dogs melanoma in the tongue, lip, hard palate, and maxilla, when treated with a combination of treatments?
Tongue - MST > 551 d
Lip - MST 580d
Hard palate - MST 330d
Maxillary - MST 320d
Lowe met rates for tongue and lip*
Although most small intestinal neoplasia is ___ in dogs, most rectal tumors are ____. Examples of the second blank?
Malignant
Benign: rectal polyps, adenomas, carcinoma in situ
What are the most common intestinal tumors in dogs and cats?
Dogs: * Lymphoma * Adenocarcinoma * GIST/leiomyosarcomas Cats: * Lymphoma * Adenocarcinoma * Mast cell tumor
What breeds of dogs are associated with predisposition of intestinal tumors? (2)In what breed of dogs are MCT overrepresented?
Collies and GSDMaltese
Infection with what bacteria is associated with an increased risk of gastric cancer in humans?Association of this bacteria an lymphoma has been reported in which spp?
Helicobacter pyloriCat
What type of intestinal cancer has been reported in a dof 4 weeks after initiation of cyclosporine and ketaconazole for anal furunculosis?
LymphomaThere is an association between cyclosporin and lymphoma in patients with transplants