Respiratory System

Question 1

Nasal planum

SCC is a relatively common tumor in ___, but rare in ___

These tumors are thought to be ____-induced and may represent a malignant transformation from keratosis or carcinoma in situ to SCC

Many cats are ___

Answer 1

cats, dogs

sunlight

white or partially white (95%)

Question 2

The prognosis after nasal planum resection is generally good in dogs.

Local recurrence was reported in two of six dogs treated with surgery alone in one study, both with incomplete histologic excision.

Seven dogs with more advanced tumors were treated with a combination of surgery and adjuvant radiation therapy (RT), and all seven dogs had local tumor recurrence with a median time to recurrence of 9 weeks.

Local recurrence was not reported in three dogs treated with combined nasal planum resection- incisivectomy and five of six dogs treated with combined nasal planum resection-bilateral maxillectomy.

Question 3

Nasal planum

The prognosis is very good in cats after surgery.

In one study of 61 cats with SCC,

local tumor recurrence was reported in less than 10% of cats,

median disease-free intervals (DFIs) of 594 days and 426 days for cats with isolated nasal planum SCC and SCC in multiple locations, respectively, when treated with surgery alone

The median survival times (MSTs) for surgically treated cats in this study were 673 days and 530 days for cats with isolated nasal planum SCC and SCC in multiple locations, respectively.

Conservative surgical approaches are not typically recommended as most nasal planum tumors are invasive and recurrence rates are high when an aggressive surgical approach is not utilized. However, surgical curettage and diathermy has been described in 34 cats with nasal planum tumors, including nine cats with carcinoma in situ and seven cats with SCC.

This technique resulted in better cosmesis and good local tumor control with a local tumor recurrence rate of 6% after a median follow-up time of 18 months

Question 4

Nasal Planum

RT: The results have been discouraging in dogs with local recurrence reported in virtually all patients with median times to recurrence of 2 to 3 months

For cats treated with orthovoltage, the 1-year progression-free survival (PFS) rate was 60%, prognostic factors

clinical stage

proliferative fraction.

The median DFIs for 55 cats treated with megavoltage in two studies was 361 to 916 days, with a MST of 902 days.

Cats with larger tumors had 5.4 and 6.3 times greater risk of recurrence and dying, respectively, than cats with smaller tumors.

For 15 cats treated with an accelerated RT protocol using protons, the PFS rate was 64% and the MST was 946 days

Question 5

Strontium Plesiotherapy

When using this technique, less than 10% of the radiation dose penetrates to a depth of 3 mm, and hence this treatment is primarily indicated for cats with superficial and minimally invasive SCCs.

In two studies totaling 64 cats treated with 90Sr,

Complete response (CR) rate was 88%;

Local recurrence was reported in 20% of cats, and 33% of cats developed new lesions in different locations.

The median progression-free interval was 1710 days (4.7 yr), with 1- and 3-year disease-free rates of 89% and 82%, respectively.
The over- all MST was 3076 days (8.4 yr), and cats with a CR had significantly longer MSTs.

Question 6

Chemotherapy: Nasal planum

The most common reported use for chemotherapy in cats with nasal planum SCC is intralesional, either alone or with electrochemotherapy.

In one study of 23 cats treated with intratumoral administration of carboplatin to treat SCC of the nasal planum, there was no systemic toxicity and local side effects were minimal and self-limiting.

A CR was noted in 73% of cats, with a 30% local recurrence rate and a mean PFS time of 16 months.

Intralesional carboplatin was combined with superficial orthovoltage RT in six cats; all cats achieved a CR and five of six cats had local tumor control at 6 months posttreatment.18

Electrochemotherapy utilizing bleomycin has been described in two case series for a total of 15 cats with nasal planum SCC.

CR was noted in 75% to 86%

DFI between 7 to 36 months.

No local or systemic side effects were noted.2

Question 7

Photodynamic Therapy

Photodynamic therapy is the use of applied light after the administration of a photosensitizer. The photosensitizer is activated by the light to form free radicals, which results in the induction of cell death

Due to the limited penetration of light into the tissue, the treatment depth is considered 5 mm or less.21

Photodynamic therapy has been described for the treatment of nasal planum SCC in cats.In a large prospective study of 55 cats treated with photodynamic therapy using 5-aminolevulinic acid (5-ALA) as a photosensitizer,

Overall response rate was 96% with 85% of cats having a CR.

51% of cats with a CR developed local recurrence w

Median time to recurrence of 157 days. At a median follow-up time of 38 months,

45% of cats were alive without recurrence and 33% of cats were euthanatized because of local recurrence.

In a study of 61 cats assessing response to photodynamic therapy based on tumor staging, 49%, 12%, and 39% of cats demonstrated complete, partial, and no responses, respectively.

The rate of CR was significantly associated with stage; CR was noted in 100% of noninvasive tumors measuring <1.5 cm in diameter, 56% of invasive tumors measuring <1.5 cm in diameter, and 18% of invasive tumors measuring >1.5 cm in diameter

Question 8

OTHER: Nasal planum

Cryosurgery, using liquid nitrogen to freeze SCC lesions, has been described in two studies totaling 101 cats, and is primarily indicated for the treatment of small (<5 mm), superficial, and noninvasive SCC lesions.

The response rate for cats with nasal planum SCC was 81% after two to three treatments.

The local tumor recurrence rates are between 17% and 73% with a median DFI of 184 days to 26.7 months

Question 9

Canine sinonasal tumors

____ breeds (long-nosed) or dogs living in urban environments, with resultant increased nasal filtering of pollutants, may be at higher risk for developing nasal cancer - not beeen proven

Risk factors?

Answer 9

Dolichocephalic

Exposure to tabacco smoke, indoor exposure to fossil fuel combusiton products

Question 10

Canine sinonasal tumors

Metastatic rate?

Answer 10

Low at diagnosis, 40-50% at time of death

Question 11

Modified Adams Clinical Staging for Nasosinal Tumors

Stage 1: confined to 1 nasal passage

Stage 2: any bone involvement

Stage 3: orbit involved, or nasopharyngeal, or SQ, or submusal mass

Stage 4: tumor causing lysis of cribiform plate

Answer 11

Stage 1: MST 23.4 months

Stage 2: 6.7 months

Question 12

Canine sinonasal tumors

Regional LN cytology is positive for metastasis in as many as 10% to 24% of cases and is most commonly associated with carcinoma.

The reported risk of pulmonary metastasis at the time of diagnosis is 2% to 10%.

Question 13

Negative predictors of survival from various studies include

Answer 13

age (>10 years)

Epistaxis

duration of clinical signs

advanced local tumor stage

Question 14

Feline sinonasal tumors

Nasal and sinus cavity tumors in the cat are malignant in more than ____ of the histologically diagnosed cases

X-rays highest predictive value for cancer include

• displacement of midline structures,
• unilateral changes such as
  
  • soft tissue opacity
  • loss of turbinate detail,
  • evidence of bone invasion.

Answer 14

90%

Question 15

Cancer of the Larynx and Trachea

Incidence and Risk Factors

• Arctic breeds, such as the Alaskan malamute or Siberian husky, account for 27% of canine laryngo-tracheal tumors.
• Significant correlations have been found between Siamese and domestic long-haired cats and lymphoma, and domestic long-haired cats and adenocarcinoma

Question 16

Young dogs, often 3 to 4 months of age, with active osteochondral ossification sites, are at a higher risk of ______, _____, and ______

Answer 16

Benign tracheal chondromas, osteochrondromas, osteochondral dysplasia

Question 17

Cats with laryngeal and tracheal masses have radiographic abnormalities in ____% of cases

Answer 17

88%

Question 18

Benign osteochondromas in young dogs have an excellent prognosis after surgical resection.

Macroscopic invasion of the trachea by thyroid carcinoma has been shown to be a significant negative predictor for DFI; this is seen in up to 24% of dogs with differentiated follicular cell thyroid carcinomas with a median survival time (MST) of 2.5 months

The prognosis for cats with tracheal carcinomas is poor as most historically have been euthanized immediately after or within a few days of diagnosis due to poor quality of life and rapid progression of disease.

Aggressive management in cats with solid laryngeal and tracheal tumors, including combinations of surgical resection, RT, and chemotherapy, have resulted in MSTs of 4 to 5 months with <10% of cats alive at 1 year.

More favorable prognoses with durable remission and survival times (STs) can be expected in cats with laryngeal and tracheal lymphoma after RT, chemother-apy, or combo

One cat with laryngeal SCC was treated with prednisolone and had a ST of 180 days.

A combination of local excision, RT, and melphalan and prednisolone was successful in long-term control of a feline laryngeal plasmacytoma.

Permanent tracheostomies in five cats with laryngeal carcinoma resulted in STs of 2 to 281 days, with two cats dying from tracheostomy occlusion and three cats from progressive disease.

Question 19

The incidence of primary lung cancer in dogs and cats presenting for necropsy is less than ____%.

Answer 19

1%

Question 20

___ cats have been reported to be overrepresented

Answer 20

Persian

Question 21

Risk fatcors for pulmonary neoplasia in dogs and cats?

Answer 21

No definitive risk factors have been identified in dogs and cats.

Question 22

Increased risk of lung cancer was found in dogs with increased amounts of anthracosis,

Anthracosis has also been correlated to high EGFR expression in canine primary lung tumors.

Cytologic analysis of bronchoalveolar lavage fluid also revealed increased anthracosis in dogs exposed to passive tobacco smoke compared with dogs without a history of exposure.

In the experimental setting, laboratory dogs trained to smoke cigarettes through a tracheostoma (in the presence or absence of asbestos exposure) did develop lung cancer at a higher rate than control dogs

Experimentally induced exposure to radiation, such as plutonium, also significantly increases the occurrence of lung cancer when inhaled as an aerosol in research dogs.

Question 23

Pulmonary tumors can arise from any tissue in the lung, but most commonly they originate from the _____ or ______.

Answer 23

epithelium of the airways, alveolar parenchyma

Question 24

Approximately 85% of canine primary epithelial lung tumors are bronchoalveolar in origin, whereas adenocarcinoma, adenosquamous carcinoma, and SCC collectively comprise the remaining 13% to 15% of primary epithelial lung tumors

Question 25

Primary pulmonary histiocytic sarcoma (HS) may also represent a significant percentage of diagnosed lung tumors, particularly in predisposed breeds such as miniature schnauzers.

Question 26

Adenocarcinoma represents 60% to 70% of feline lung tumors, whereas bronchoalveolar carcinoma, SCC, and adenosquamous carcinoma are less common.

Question 27

Small cell carcinoma represents approximately 25% of human pulmonary neoplasms, but rarely occurs in the dog or cat.

Question 28

Lung tumors can spread by local invasion or via hematogenous and lymphatic routes, resulting in locoregional spread to other areas of the lung or LNs, or distant metastasis.

Intrapulmonary metastases are believed to occur through vascular and lymphatic invasion or intraairway seeding.

Local vascular or lymphatic invasion was present in 71% of canine pulmonary malignant tumors in one study, and 23% had distant metastasis beyond the tracheo- bronchial LNs.

SCC and anaplastic carcinomas have metastatic rates exceeding 50% and 90%, respectively, and are more likely to metastasize than adenocarcinoma or bronchoalveolar carcinoma.

Question 29

Metastasis is common in the cat with a reported metastatic rate of 76%.

The size of the largest mass has also been associated with metastatic potential in the cat. Metastasis to bone or the nervous system is not uncommon in dogs or cats.

Metastasis to he digits, otherwise known as acrometastasis or lung-digit syndrome, is a common and well-described clinical phenomenon in cats.

Question 30

The most common clinical sign reported in dogs with pulmonary neoplasia is coughing, which is noted in 52% to 93% of dogs.

Other clinical signs include dyspnea (6%–24%), lethargy (12%–18%), hyporexia (13%), weight loss (7%–12%), hemoptysis (3%–9%), and lameness, likely secondary to hypertrophic osteopathy (HO, 4%).

Question 31

Clinical signs in cats:

signs referable to the respiratory tract are common with dyspnea (20%–65%), cough (29%–53%), tachypnea (9%–14%), and hemoptysis (10%) being noted regularly.

Question 32

Several reports of cats with concurrent pulmonary neoplasia and digit metastasis can be found in the veterinary literature; this phenomenon has been noted with both pulmonary adenocarcinoma and SCC.

Question 33

Immunohistochemistry or possibly immunocytochemistry using antibodies directed against thyroid transcription factor-1, cytokeratin, vimentin, or others may be useful in differentiating primary lung tumors from metastatic disease.

Antibodies against CD18 and CD204 may also be useful for differentiating pulmonary tumors of histiocytic origin.

Question 34

Prognostic factors included the presence of clinical signs,

• Dogs with clinical signs associated with a primary lung tumor had an MST of 240 days compared with 545 days for asymptomatic dogs

clinical stage,

• Dogs with single solitary lung tumors (T1 clinical stage) had an MST of 790 days, which was significantly longer than dogs with multiple lung tumors (T2 clinical stage, 196 days) and dogs with lung tumors invading into adjacent structures (T3 clinical stage, 81 days).

tumor type

histologic grade

MST for dogs with grade I lung carcinomas was 790 days, and this was significantly longer than the MSTs of 251 days and 5 days for dogs with grade II and III lung carcinomas, respectively.281

Question 35

Factors significantly associated with remission included limited degree of primary tumor involvement,

In a separate study of 15 dogs, trends for longer STs were noted in dogs with adenocarcinoma versus SCC, dogs with peripheral lesions versus lesions that involved an entire lobe, and dogs with tumor volume <100 cm3 compared with dogs with tumor volume >100 cm3.282

normal sized LNs,

The MST for dogs with no evidence of LN (N0) was 452 days, and this was significantly longer than the MST of 26 days for dogs with tracheobronchial LN metastasis (N1).281

In another study, dogs with LN enlargement diagnosed before surgery survived for a median time of 60 days, whereas dogs without LN enlargement had a MST of 285 days.

A similar finding was noted in a more recent study where dogs with lymphadenomegaly had MSTs of 126 days versus a MST that had not been reached in the dogs without lymphadenomegaly.284

lack of metastatic disease.

Question 36

In dogs for which a surgical remission could be achieved, MST is 330 days versus 28 days in dogs that could not be rendered free of visible disease.

Although not statistically significant, the mean ST of dogs with SCC was 8 months and the mean ST of dogs with adenocarcinoma was 19 months in one study.282

Question 37

The prognosis is guarded to poor for cats with primary lung carcinomas. In one retrospective study of 21 cats treated with lung lobectomy,28

overall MST was 115 days (4 mo).

The only prognostic factor in this study was histologic grade; the MST for cats with moderately differentiated carcinomas was 698 days compared with only 75 days for cats with poorly differentiated carcinomas.

In a separate study, cats with low-grade tumors had an MST of 730 days compared with 105 days for cats with high-grade tumors.287

Question 38

Similar to dogs, LN enlargement in cats significantly decreased MST to 65 days from 498 days for cats with no evidence of lymphadenomegaly.

The TNM staging scheme also correlated with ST in cats; cats staged T1N0M0 live significantly longer than cats with higher stages.

In this same study, the MST in cats with clinical signs was 4 days compared with 578 days in asymptomatic cats.2

Pleural effusion has been identified as a negative prognostic factor;

Two studies, the MST were less than 3 days and 31 to 467 days in cats with and without pleural effusion, respectively.