Oncology 2

Question 1

Components of staging

Answer 1

1. TNM classification
2. Primary
3. Lymph node
4. Distant metastasis
5. Microscopic vs. Gross Dz

Question 2

TNM classification

Answer 2

TMN staging
1. T= tumour size (primary)
2. N= Lymph node
3. M= Distant metastasis

Question 3

TNM classification example (Canine oral tumour)

Answer 3

Question 4

Tumour size

Answer 4

-physical exam- external measurement but sometimes only shows the tip of the iceberg

Question 5

Advanced imaging

Answer 5

1. CT
2. MRI

Question 6

CT imaging

Answer 6

-sedation/anesthesia

Used for soft tissue/bone/lungs

Question 7

MRI

Answer 7

-expensive
-anesthesia
-time extensive so must be a stable patient

Used for soft tissue, muscle, nerve

Question 8

Lymph node

Answer 8

-check what lymph node is draining tumour
-neoplasia on back end- check lymph nodes on rectal exam (non palpable lymph nodes)

Question 9

FNA screening

Answer 9

Conduct FNA on masses
-Normal size does not mean that there is no metastasis (will see in in 20-46%)
-Cytology can miss tumour if needle not placed perfectly

**histopathology is the gold standard though!!

Question 10

Ultrasound for internal lymph nodes

Answer 10

Look for:
-size
-short/long axis ratio
-homogenecity

But issue with bones and can miss, so use advanced imaging (eg. Sacral/intrathoracic LN)

Question 11

CT testing accuracy

Answer 11

Sensitivity: 10-12%
Specificity: 91-96%

Question 12

Cancer lymphatics/drainage

Answer 12

Tumour may be located in area that should drain in one area, but 28-62% of the time the tumour is actually draining to another lymph node (*can make their own lymphatics)

Question 13

Sentinel lymph node

Answer 13

Determine the 1st draining lymph node
-inject dye, radioopaque agent, near-infrared fluorescence

Question 14

When is sentinel lymph node mapping used?

Answer 14

For cancers that commonly metastasize to LNs
ex. mast cell tumours, oral tumours, anal sac carcinomas

Question 15

Common Distant metastasis

Answer 15

1. Lungs
2. Abdomen (liver, kidneys, spleen, etc.)
3. Brain/CNS
4. Skin/Bone

Question 16

Evaluating lung metastasis

Answer 16

3 view or 4 view rads/CT

Question 17

Evaluating Abdomen (liver, kidneys, spleen, etc.) metastasis

Answer 17

-abdominal US/CT +/- FNA

Question 18

Evaluating brain metastasis

Answer 18

-neuro exam
-CT/MRI

Question 19

Evaluating skin/bone metastasis

Answer 19

-physical exam

Question 20

Co-morbidities in senior patients

Answer 20

-Conduct abdominal US, Systemic CT, and FDG-PET/CT (inject radioactive component to glucose, and tumours love glucose and will suck it up and ID location)

Question 21

TMN variations

Answer 21

-actual classification into stages are based on the tumour type and the TNM
(eg. canine oral tumours and cutaneous mast cell tumours have different staging based on TNM)

Question 22

Microscopic and gross disease

Answer 22

1. When microscopic, easier to miss parts and will result in recurrence
   *sometimes no recurrence because immune system might be good enough to kill remaining tumour cells
2. tumour completely removed (Eg. remove leg) but maybe it already went to the blood= Metastasis
   *often reason that chemotherapy happens after surgery

Question 23

Factors to consider in staging

Answer 23

-risks, cost, benefit
-accessibility (eg. PET-CT)
-metastasis likelihood
-monitoring

Question 24

How much staging should be done?

Answer 24

1. Localized tumour- minimal metastasis, so minimum database needed
2. Microscopic metastasis - likely need chest imaging, abdominal/cardiac US
3. Hematopoietic systemic tumour
   -can stage but already know that it is systemic so not needed if you are already doing treatment anyways

Question 25

Why staging matters?

Answer 25

-treatment/monitoring plan changes 2. prognosis changes