cancer

what is the definition of “tumor”

swelling of a tissue caused bu an abnormal growth of cells

what is the definition of “metastasis”

spread of cancer from its origin to other tissues

what is local metastasis?

cancer spreads to the regional lymph nodes

what is distant metastasis?

cancer spreads to other organs, including lung (common) and liver

what is the definition of “benign tumor”

a tumor that is unlikely to metastasize but can still have a negative impact on quality of life

what is the definition of “malignant tumor/cancer”

a tumor w/ the potential to metastasize

what two key pieces of information do you need to determine treatment options?

1. what type of tumor are you dealing with?

2. has the tumor spread anywhere else in the body?

T/F - biopsies allow pathologists to assign a grade to samples.

true!

what procedures can you do to know what type of tumor you’re dealing with?

1. FNAs

2. biopsy

what is the definition of “grading”

based on microscopic features correlated to a tumor’s likely behavior

what is the definition of “staging”

the process of performing diagnostic tests to determine the extent of cancer within the body.

what is tumor stage determined by?

• local extent of the tumor

• presence of metastasis in lymph nodes and distant sites

what tests do we usually perform to stage a pet’s cancer?

• x-rays

• US

• CT

• biopsy

• FNAs

what are the two types of treatment options for cancer?

• local therapy

• systemic therapy

what are the types of local therapy?

• surgery

• radiation therapy

what are the different types of radiation therapy?

• palliative

• definitive

what are the different types of systemic therapy?

• cytotoxic chemotherapy drugs

  • small-molecule inhibitors

what is the definition of “complete remission”

all of the grossly detectable tumor is gone

what is the definition of “partial remission”

most of the grossly detectable tumor is gone (30-50%)

what is the definition of “stable disease”

the tumor hasn’t gotten smaller, but it also hasn’t grown

what is the definition of “progressive disease”

the tumor is growing or new tumors have formed

when do acute side effects of radiation therapy occur?

• occur in rapidly dividing tissues (skin + GI)

• occur during the course of radiation delivery

when do late side effects of radiation therapy occur?

• occur in slow dividing tissues (connective tissues, bone, + nerves)

• occur a long time after radiation therapy delivered

what are some acute effects of radiation therapy?

• alopecia

• dry desquamation (damaged skin)

• moist desquamation

• mucositis

what are some acute effects of radiation therapy?

• permanent alopecia

• leukotrichia (white hair follicles)

• fibrosis (scarring)

• osteonecrosis (dead bone)

• keratoconjunctivitis sicca (dry eye)

• cataracts

• second cancer (rare)

what causes the side effects of chemotherapy?

injury to rapidly dividing cells other than cancer cells like precursor cells in the bone marrow, intestinal crypt cells in the intestines and hair follicles

• BAG

  • B -bone marrow

  • A - alopecia

  • G - gastrointestinal disturbances

what are other common chemotherapy side effects?

• extravasation of chemo drugs

• cardiotoxicity

• nephrotoxicity

• hepatotoxicity

• fatal pulmonary edema in cats

• sterile hemorrhagic cystitis

• PU/PD/polyphagia/panting

what are common cancers in the dog?

• lymphoma

• osteaosarcoma

• mast cell tumor (MCT)

• hemangiosarcoma

• dermal hemangiosarcoma

• soft tissue sarcoma

• transitional cell sarcoma (TCC)

what age group and breeds are most affected by lymphoma?

• middle aged-older dogs

• golden retrievers*, boxers*, basset hound, labrador retriever, german shepherd

what’s the most common presenting sign for lymphoma?

non-painful generalized peripheral lymphadenomegaly

what are the locations of superficial lymph nodes?

• mandibular

• prescapular

• axillary

• inguinal

• popliteal

which superficial lymph nodes are normally palpable compared to the rest?

• mandibular

• prescapular

• popliteal

what is the gold standard treatment for lymphoma patients?

• CHOP

  • cyclophosphamide

  • vincristine

  • doxorubicin

  • prednisone

what breeds are most affected by lymphoma?

• large to giant breed dogs

  • rottweilers, saint bernards, golden retrievers, great danes, german shepherd

what’s the most common presenting sign for osteosarcoma?

similar to an injury to a joint and ,ay progress from mild or intermittent lameness to non-weight bearing lameness 2/ swelling of local soft tissue

what are common locations for osteosarcoma?

• away from elbow

  • proximal humerus

  • distal radius

• toward knee

  • distal femur

  • proximal tibia

what is the gold standard treatment for osteosarcoma patients?

amputation

is surgery is not done, what other course of action can be taken to make sure your osteosarcoma patient is comfortable?

• NSAIDs

• tramadol

• gabapentin

• bisphosphonates

• radiation therapy

why is systemic therapy often indicated after amputation of an osteosarcoma pt?

it is highly metastatic

T/F - mast cell tumor is the most common skin cancer in the dog.

true

which breeds are predisposed to MCT?

mainly brachycephalic breeds (pugs, boxers, boston terriers) but can also be seen in labrador retrievers, staffordshire terriers, and shar-peis

what are some important questions to ask owners during history when looking at a MCT pt and why?

• ask abt: vomiting, diarrhea, dark colored stools (melena) and anorexia

• could indicate GI ulceration due to histamine release

what are treatments for MCT?

• surgery

• chemotherapy

what is hemangiosarcoma?

cancer that arises form the lining of blood vessels

where does hemangiosarcoma most often happen?

spleen

where else can a hemangiosarcoma occur?

the heart

what breeds are predisposed to hemangiosarcoma?

german shepherds, golden retrievers, labrador retrievers

what are some clinical signs of hemangiosarcoma (HSA)?

• pale gums

• distended abdomen

• palpable fluid wave

• weak femoral pulses

• exercise intolerance

• weakness

• collapse

• tachypnea

what are some treatments for HSA?

• splenectomy

• chemotherapy

what is a dermal hemangiosarcoma?

dark dots on skin induced by UV light radiation

how can dermal hemangiosarcoma be treated?

surgical excision

where can soft tissue sarcomas occur?

anywhere in the body, usually limbs

what ways can be used to treat soft tissue sarcomas?

surgery and radiation

what is transitional cell carcinoma (TCC)?

tumor of urinary tract

which breeds are predisposed to TCC?

scottish terriers, west highland white terriers, shetland sheep dog, beagles, wire haired fox terrier

what are some common signs of TCC?

• urinary tract infection symptoms like:

  • stranguria

  • hematuria

  • pollakuria

  • dysuria

  • recurrent urinary tract infections

    • maybe: lameness, weight loss, lethargy

what are risk factors of TCC?

• breed

• exposure to old flea dips

• exposure to herbicides

• cystocentesis risks spreading TCC

• cigarette smoke

which vegetables can be used to decrease the risk of TCC?

broccoli and carrots

what are some treatments for TCC?

• injectable chemo

• NSAIDs

• radiation

• urethral or ureteral stents

what are common cancers in the cat?

• lymphoma

• feline injection site sarcoma (FISS)

• oral squamous cell carcinoma

how does lymphoma usually present in cats?

• alimentary/GI tract

• mediastinal lymphoma

• extranodal - nasal, renal, CNS, and retrobulbar

what’s the most common type of GI lymphoma in cats?

low grade, small cell variant

what are some clinical signs of GI lymphoma in cats?

• anorexia

• diarrhea

• vomiting

• weight loss

what are clinical signs of nasal lymphoma?

• nasal discharge

• sneezing

• stridor/stertor

• ocular discharge

• facial asymmetry

how do feline injection site sarcomas (FISS) form?

associated with vaccination and other injection sites

why is injection site important in relation to FISS?

because vaccines used to be given between the shoulder blades and the sarcomas would go unnoticed by owners until the tumor was too big to surgically remove

where should vaccines be administered in case a patient formed a FISS and needed an amputation?

• limbs

• tail

what are the AAFP recommended vaccine locations?

• right front

  • feline panleukopenia

  • feline herpesvirus-1

  • feline calicivirus

• right rear

  • rabies

• left rear

  • FeLV

what is the AAFP’s 3-2-1 rule pertaining to when to biopsy a lump that develops post-injection?

• a lump that persists for 3 months+

• a lump becomes larger than 2 cm in diameter

• a lump continues to increase in size for >1 month after an injection

what’s the most common oral tumor in cats?

oral squamous cell carcinoma

where can oral squamous cell carcinoma develop?

anywhere in the mouth

what are risk factors for oral squamous cell carcinoma?

• tobacco smoke

• ± high intake of canned food

• ± flea collars (of the older brands)

what are some clinical signs of oral squamous cell carcinoma?

• blood stained water or saliva

• ptyalism (excessive salivation)

• pain on palpation of face or jaw

• halitosis (fetid odor to breath)

• scratching or pawing at face

• anorexia and/or weight loss

• ± observing mass

what are treatment options for oral squamous cell carcinoma?

radiation and chemotherapy (± surgery depending on tumor)

what are some non-cancerous lesions in the mouth that cats are commonly diagnosed with?

• proliferative gingivostomatitis
  stomatitis secondary to viral infections

• eosinophilic or rodent ulcers

• feline oral resorptive ulcers

• nasopharyngeal polyps