Oncology 9 (Oral and GI Tumors)

What are the most common oral tumors in dogs?

1. melanoma

2. squamous cell carcinoma

3. fibrosarcoma 

_% of oral tumors in dogs are benign

~5%, epulides

What are the mot common oral tumors in cats?

1. squamous cell carcinoma (SCC)

2. SCC

3. SCC

4. SCC…

5. fibrosarcoma

What are some clinical signs of oral tumors?

Halitosis

Difficulty chewing, may favor one side of mouth

Drop food out of mouth

Ptylasim - ropey, viscous, often tinged saliva dripping from mouth

Blood in water bowl

Oral tumors can be ____ found on ___.

incidental finding,

routine teeth cleaning or on annual check up 

Where are oral tumors located?

any place in oral cavity,

most commonly along gum line, 

hard palate, soft palate, frenulum, cheeks

Oral tumors can invade into surrounding tissues, including __.

bone

True or False? Staging for oral tumors are similar across types, so you don’t have to know the exact tumor type prior to checking for metastasis.

True

The rates of __ and __ differ between oral tumor types.

invasion, metastasis

True or False? Most malignant oral tumors metastasize at similar rates just at different locations.

False. Most malignant oral tumors metastasize at similar LOCATIONS just at different rates. 

For all oral tumors evaluate for both ___ and ___.

extent of local disease,

metastasis

What is a prognostic indicator with local disease of oral tumors?

size of primary tumor

Where to oral tumors tend to metastasize?

regional lymph nodes, lungs

other: depending on tumor type

What diagnostics are used for staging oral tumors?

• routine bloodwork (CBC, chemistry)

• Imaging of oral cavity (CT preferred over skull radiographs)

• Regional lymph node evaluation (sentinel lnn mapping, attempt to aspirate, remove at surgery)

• Imaging of thoracic cavit (3v CXR, CT scan) 

What is the most common oral tumor in dogs?

Oral malignant melanoma (OMM)

What signalment (age, breed) is seen with OMM?

Older, median 12 years

Breeds: chows, Goldens, Poodles, Cockers etc

Smaller weight dogs may be over-represented but occur in any breed

What clinical signs are seen with OMM?

visible mass (pigmented or not ~30%)

bleeding

halitosis

ptyalism

Describe the behavior of OMM

• almost ALWAYS malignant 

• majority invades bone (locally invasive)

• metastasis is COMMON

  • LNs and lungs most common

  • tonsils

  • other sites

What diagnostics can be used if OMM is suspected?

FNA and cytology (melanomas exfoliate readily)

Biopsy and histopathology (consider sx planning)

Often need IHC for confirmation/guide treatment

Why is OMM diagnosis sometimes difficult?

Can appear similar to other tumors (round cell, carcinoma, sarcoma)

~1/3 of cases are amelanotic (no pigment)

How can you tell a cytology of melanoma vs MCT apart?

Melanoma will have dark gray/black/purple pigment granules,

MCT granules are more red/pink and often have eosinophils around

What IHC stains should be included in a OMM panel?

Melan A,

S100,

PNL2, 

TRP-1,

TRP-2

__ is the most common IHC stain. A negative IHC stain with this stain does/does NOT rule out melanoma.

Melan A

DOES NOT r/o melanoma

What diagnostics can be used to stage OMM?

• CBC, serum chemistry

• LN cytology - even if normal in size (40% have LN mets)

• Thoracic imaging - CT or 3v rads

• Local imaging of mass - CT of head, planning of sx and/r RT

How is OMM clinially staged?

TNM based staging 

Describe TNM staging in OMM

T1: tumor </= 2cm diameter

T2: tumor 2-4cm diameter

T3: tumor >4cm diameter

N0: no evidence of regional ln

N1: histologic/cytologic evidence of regional ln

N2: fixed nodes

M0: no distant met

M1: distant met

What is the TNM for Stage 1 OMM?

T1 N0 M0

What is the TNM for stage 2 OMM?

T2 N0 M0

What is the TNM for stage 3 OMM?

T2 N1 M0 or T3 N0 M0

What is the TNM stage for stage 4 OMM?

Any T, Any N, M1

What is the treatment for OMM?

local therapy (surgery and radiation) proven to be effective

systemic therapy (chemo, immunotherapy, NSAIDs) NOT proven to be effective

MST of OMM if NO treatment?

2 months (due to painful QOL)

For a mandibulectomy what is the MST and recurrence?

MST 9-11 months

22% recurrence 

For a maxillectomy what is the MST and recurrence?

MST 5-10 months

up to 50% recurrence

True or False? OMM is radiation sensitive.

True!

What is the MST, local recurrence, and response rate of radiation therapy for OMM?

MST 4-12 months

Local recurrence 11-27%

Response rate 83-94%

True or False? The cause of death from OMM when doing radiation therapy is often due to the local mass invasion.

False. Cause of death most often due to metastasis.

Dr. L only considered chemotherapy for OMM in what situations?

Considered for gross metastasis in the lungs — still not great tho

If chemo is used for OMM, what chemotherapeutic drugs are used?

Carboplatin

Palladia

What is the response rate with carboplatin in gross OMM disease? For microscopic disease?

gross disease - 28%

microscopic disease - no proven benefit

What immunotherapy can be used for OMM?

melanoma vaccine

The melanoma vaccine used for immunotherapy is a ___ vaccine.

Xenogenic DNA

The target gene for the melanoma vaccine is ___.

human tyrosinase - glycoprotein essential for melanin synthesis

How effective is the melanoma vaccine as an added treatment to surgery?

Some studies show improved survival for patients receiving vx other studies show no difference in survival

Very $$$

What is the OMM MST following surgery if the P is less than 12 yrs? 12 yrs or older?

<12 yrs - 630 days, 21 months

>/=12 yrs - 224 days, 7.5 months

What is the OMM MST following surgery based on the tumor size?

<2 cm - 630 days, 21 months

2-4 cm - 240 days, 8 months

>4 cm - 173 days, 5.7 months

What is the OMM MST following surgery based on metastasis at diagnosis?

No mets - 818 days, 27 months

Mets - 131 days, 4.3 months 

What the OMM MST following surgery based on clinical stage?

Stage 1 - 874 days, 29 months

Stage 2 - 818 days, 27 months

Stage 3 - 207 days, 6.9 months

Stage 4 - 80 days, 2.6 months

Oral squamous cell carcinoma (SCC) in dogs is __% of oral tumors.

<25% 

What signalment (age, breed) of dogs are associated with oral SCC?

Older, 8-10 years

Large breed dogs

True or False? While OMM in dogs often have metastasis, oral SCC mets are less common.

True!

For oral SCC in dogs, __% met to lungs, __% met to lymph nodes. With Tonsillar SCC, up to __%

<35% - lungs

<10% - lymph nodes

70% tonsillar SC

How is oral SCC in dogs diagnosed?

cytology, histopathology

How is oral SCC in dogs staged?

LN evaluation, thoracic imaging

What is the treatment for oral SCC in dogs?

• surgical resection is the standard of care

  • mandibulectomy

  • maxillectomy

• radiation therapy (not as good as in OMM)

  • palliative for gross, curative for microscopic

• Piroxicam (COX2 NSAID)

__% of mandibulectomy in oral SCC dogs are alive at 1 year with a __% recurrence. Compared to __% of maxillectomy dogs at 1 year with a __% recurrence.

manidulectomy - 91% alive at 1yr, 10% recurrence

maxillectomy - 57% alive at 1yr, 30% recurrence

Piroxicam has a __ response rate for oral SCC.

17% 

What are the general prognostic factors for oral SCC in dogs?

Location - rostral vs caudal

Complete vs incomplete resection

Presence of metastasis

What is the 3rd most common oral tumor in dogs?

oral fibrosarcoma (FSA)

What signalment (age, breed) are affected by oral fibrosarcoma (FSA)?

large breed dogs, goldens, labs

younger age, 7-8 yrs

(cats rarely get this too)

Describe the behavior of oral fibrosarcoma in dogs

occasiona lmetastasis, common bone involvement often the hard palate

Histologically the oral FSA is __ grade and biologically __ grade

histo - low

biologically - high

*difficult to differentiate from a fibroma on histopathology

What is the treatment of choice for oral FSA in dogs?

aggressive surgery ± RT

About __% of oral FSA in dogs met to lungs, about __% to LNs.

lungs - 12%

LNs - 20%

What are epulides? What are two types?

benign gingival proliferations 

1. acanthomatous ameloblastoma

2. peripheral odontogenic fibroma 

An epulis is seen on the rostral mandible and appears to be very aggressive locally. What type of epulide is most likely?

Acanthomatous ameloblastoma

What age of animal do you see acanthomatous ameloblastoma?

7-10 yrs, more common in dogs than cats 

An epulis is seen on the maxilla rostral to 3rd premolar. It is slow-growing, firm, and covered by epithelium. What type of epulis is most likely?

peripheral odontogenic fibroma 

___ epulides frequently invade bone whereas ___ epulides tend not to invade bone.

acanthomatous ameloblastoma,

peripheral odontogenic fibroma

True or False? Peripheral odontogenic fibromas are rare in cats but 50% occur in middle aged cats >3 yrs.

False. 50% occur in YOUNG CATS <3 yrs

__% of oral tumors in cats are oral squamous cell carcinoma (SCC)

70-80%

Where does oral SCC in cats like to present?

tongue, pharynx, tonsils

True or False? Oral SCC in cats is very invasive, most will have bone involvement so local control is difficult and metastasis is common.

False. Metastasis is UNCOMMON, but it is locally very invasive with bone involvement

What are proposed etiologies for oral SCC in cats?

flea collars (old generation), canned food, canned tuna, ± exposure to cigarette smoke

How is oral SCC in cats diagnosed?

cytology, histopathology

What diagnostics are done to stage oral SCC in cats?

• bloodwork

• LN evaluation - cytology

• CT imaging often needed for surgical/RT planning

• thoracic imaging (rads/CT)

What is the best treatment for oral SCC in cats?

aggressive sx resection

What must you warn owners about if they are considering surgical resection of their cat’s oral SCC?

Cats often have difficulty eating for 2-4 months post-sx,

Enteral feed tube may be required/recommended

12% of cats never eat voluntarily after sx :(

Besides surgical resection of oral SCC in cats, what other treatments can be considered?

radiation - alone or in combo (sx ± chemo), palliative is minimally effective

chemo - poor response

palliative care - NSAID, pain medications

oral SCC in cats can be frustrating as a medical oncologist to consult on — why?

Very little we can do medically, and quite limited if not surgically resectable…

Summary table for oral tumors in dogs

Malignant Melanoma

1. frequency

2. median age yrs

3. site predilection

4. LN mets

5. distant mets

6. gross apperance

7. Sx response

8. RT response

9. Best tx

10. Cause of death 

Summary table for oral tumors in dogs

1. frequency = 30-40%

2. median age yrs = 12

3. site predilection = gingival, buccal, labial mucosa

4. LN mets = common, 41-74%

5. distant mets = common, 14-92%

6. gross appearance = pigmented (67%), amelanotic (33%), ulcerated

7. Sx response = fair to good

8. RT response = good

9. Best tx = surgery and/or RT ±chemo, ±immunotherapy

10. Cause of death = local or distant disease 

Summary table for oral tumors in dogs

Squamous Cell Carcinoma

1. frequency

2. median age yrs

3. site predilection

4. LN mets

5. distant mets

6. gross appearance

7. Sx response

8. RT response

9. Best tx

10. Cause of death 

Summary table for oral tumors in dogs

1. frequency = 17-25%

2. median age yrs = 8-10 yrs

3. site predilection = rostral mandible 

4. LN mets = rare<40%, tonsil up to 73%

5. distant mets = rare<36%

6. gross appearance = red, cauliflower, ulcerated

7. Sx response = good

8. RT response = good

9. Best tx = surgery and/or RT

10. Cause of death = local or distant disease

Summary table for oral tumors in dogs

Fibrosarcoma 

1. frequency

2. median age yrs

3. site predilection

4. LN mets

5. distant mets

6. gross appearance

7. Sx response

8. RT response

9. Best tx

10. Cause of death 

Summary table for oral tumors in dogs

1. frequency = 8-25%

2. median age yrs = 7-9 yrs

3. site predilection = maxillary gingiva and hard palate 

4. LN mets = occasional 9-28%

5. distant mets = occasional 0-71%

6. gross appearance = flat, firm, ulcerated

7. Sx response = fair to good

8. RT response = poor to fair

9. Best tx = surgery and/or RT

10. Cause of death = local disease 

Summary table for oral tumors in dogs

Acanthomatous Ameloblastoma (epulis)

1. frequency

2. median age yrs

3. site predilection

4. LN mets

5. distant mets

6. gross appearance

7. Sx response

8. RT response

9. Best tx

10. Cause of death 

Summary table for oral tumors in dogs

1. frequency = 5%

2. median age yrs = 8 yrs

3. site predilection = rostral mandible

4. LN mets = none

5. distant mets = none

6. gross appearance = red, cauliflower, ulcerated

7. Sx response = excellent :)

8. RT response = excellent

9. Best tx = surgery

10. Cause of death = rarely tumor related

Summary table for oral tumors in cats 

Squamous Cell Carcinoma

1. frequency

2. median age yrs

3. site predilection

4. LN mets

5. distant mets

6. gross appearance

7. Sx response

8. RT response

9. Best tx 

10. Cause of death

Summary table for oral tumors in cats  

1. frequency = 70-80%

2. median age yrs = 10-12 yrs

3. site predilection = tongue, pharynx, tonsils

4. LN mets = rare

5. distant mets = rare

6. gross appearance = proliferative, ulcerated

7. Sx response = poor :( 

8. RT response = poor :(

9. Best tx = surgery and RT 

10. Cause of death = local disease

Summary table for oral tumors in cats 

Fibrosarcoma

1. frequency

2. median age yrs

3. site predilection

4. LN mets

5. distant mets

6. gross appearance

7. Sx response

8. RT response

9. Best tx 

10. Cause of death

Summary table for oral tumors in cats 

1. frequency = 13-17%

2. median age yrs = 10

3. site predilection = gingiva

4. LN mets = rare

5. distant mets = rare

6. gross appearance = firm

7. Sx response = fair

8. RT response = poor

9. Best tx = surgery and/or RT

10. Cause of death = local disease 

Overall gastric tumors are __ with __% of maligancies.

rare, <1%

Dogs tend to get what type of gastric tumors?

adenocarcinoma (70-80%)

smooth muscle tumors, GIST, lymphoma, others

Cats tend to get what type of gastric tumors?

lymphoma - solitary or component of higher stage dz

adenocarcinoma is rare

What are the risk factors for gastric tumors (adenocarcinoma) in dogs?

breed - Belgian shepherds, rough coated collies

male sex 2.5:1 M to F ratio

What are the risk factors for gastric tumors (lymphoma) in cats?

chronic gastritis

H. pylori infection

What clinical signs are seen with gastric tumors?

vomiting, anorexia, weight loss, anemia

signs may be prolonged

How are gastric tumors diagnosed?

• imaging: radiographs ± contrast, ultrasound, CT

• biopsies and histopathology: endoscopy, sx 

True or False? Surgery, RT, Chemo, and NSAIDs are possible treatment options for gastric tumors.

False. While surgery, chemo, and NSAIDs can be considered depending on gastric tumor, RT is NOT used due to surrounding tissues.

Surgery for gastric masses can be difficult. Why?

Due to location and need to evaluate for intra-abdominal metastasis. (Billroth procedures)

What types of gastric tumors could chemotherapy be considered for?

not effective for adenocarcinomas

GISTs, lymphoma may be exceptions for chemo!

What types of gastric tumors could NSAIDs be considered for?

adenocarcinomas

What types of intestinal tumors are most commonly seen in dogs?

1. lymphoma

2. adenocarcinoma

3. leiomyosarcoma

4. gastrointestinal stromal tumors (GIST)

5. carcinoids

What types of intestinal tumors are most commonly seen in cats?

1. lymphoma

2. adenocarcinoma

3. MCT

What clinical signs appear with proximal intestinal tumor lesions?

vomiting, anorexia, weight loss, melena