Diagnosis and Surgical Management of Oral Cancer Flashcards
Oral cancers are part of a group of cancers commonly referred to as head and neck cancers,
and they comprise about –% of that category.
85
Oral cancer can develop in
any part of the oral cavity or the oropharynx
Origin of Malignancies in the Oral Cavity
(4)
- Epithelium:
- Connective Tissue:
- Salivary Gland:
- Metastatic disease:
- Epithelium:
“90% of oral cancer cases is Squamous cell carcinoma” and they arise in
epithelial surface layer of oral mucosa.
- Connective Tissue:
Sarcomas account for 2% of oral cancer cases. For e.g. Osteosarcoma,
Chondrosarcoma, Ewings sarcoma, Kaposi’s sarcoma, Lymphoma etc.,
- Salivary Gland:
Accounts for 4 to 8% of oral cancer cases. For e.g. Mucoepidermoid carcinoma,
Adenoid cystic carcinoma, Adenocarcinoma, Acinic cell carcinoma etc.,
- Metastatic disease:
Accounts for less than 1%, of oral cancer cases. Most originate from common
primary sites including lung, kidney, skin (melanoma), prostate in men and breast in women. Metastatic to
Mandible and occasionally soft tissues i.e to gingiva or tongue.
“—” is the most common oral malignancy that accounts for –%
of all Oral cancers).
Squamous cell carcinomas
90
- Lip - –%
- Tongue - –%
- Floor of the Mouth - –%
- Palate/tonsil - –%
- Gingiva - –%
- Other - –%
38
22
17
11
6
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The Importance of Oral Cancer Screening
- Early diagnosis, prompt referral and appropriate treatment is critical for favourable
long term prognosis and survival of patients with oral cancer
he Spread of Oral Squamous Cell Carcinoma
Local Invasion
Squamous cell carcinoma of the oral cavity first grows locally by progressive infiltration,
invasion and destruction of the surrounding tissue leaving them poorly demarcated
Squamous cell carcinoma of the oral cavity first grows locally by progressive infiltration,
invasion and destruction of the surrounding tissue leaving them poorly demarcated.
* Important to local extension is the …
* Muscle is easily invaded while periosteum offers a …
anatomic location of the tumor and the adjacent tissues next to
the tumor.
good barrier to invasion.
The Spread of Oral Squamous Cell Carcinoma
Regional Spread through Lymphatic Spread
As the tumor progresses,
the oral cancer spreads to the regional lymph nodes of the neck through the
lymphatic channel.
This is the most important and most frequent pathway for the spread of oral squamous cell
carcinoma.
The Spread of Oral Squamous Cell Carcinoma
Regional Spread through Lymphatic Spread
- The cancer invades the local lymphatic supply and travels to the regional lymph node(s)
draining the site. - Usually oral squamous cell carcinoma spreads to the ipsilateral cervical lymph nodes i.e lymph
nodes on the same side of the neck as the cancer. - The lymph node containing the tumor cells is typically firm to stony hard (Indurated), non-
tender and enlarged. - Lymph nodes are freely movable at first but as the tumor breaks through the capsule, the node
becomes fixed. - Lymphadenopathy does not indicate metastasis for certain as it can result from inflammation
associated with the presence of tumor also.
The Spread of Oral Squamous Cell Carcinoma
Distant Metastasis Through Hematogenous Spread
* In the later stages of the disease process, the tumor …
spreads into the vascular channel
(hematogenous metastasis) and may seed other parenchymal sites if tumor invasion is not
controlled at the lymphatic level.
- The usual sites of secondary spread (distant metastases) include the (5)
lungs, liver, bone, brain, and
adjacent skin, as well as other sites, depending on the tumor histology
Oral Cancer – Diagnosis and Workup
(6)
- Health History
- Detailed Patient History
- Head and Neck examination
- Imaging Studies - Radiographs, CT Scan/MRI exam, Bone Scan, PET Scan
- Biopsy
- Staging and Grading of Oral cancer
Health History
- It is important to evaluate the medical status of the patient in detail before
finalizing a surgical treatment plan.
Detailed Patient History - Signs and Symptoms
(9)
- Painless lump or ulcer (in the early stages)
- Posteriorly no symptom until it reach a size of 2-3 cm swelling then manifests as dysphagia
- Ear pain
- Difficulty in moving the jaw or tongue
- Hoarseness
- Paraesthesia (Tongue, lip etc.,)
- Swelling
- Non healing ulcer
- Absence of symptoms until the tumor metastasize to regional lymph nodes (hard lump on the
neck)
Indirect Laryngoscopy
- As patients diagnosed with oral cancer are also at increased risk for other head and
neck cancers, it is important to examine other areas of the throat for any additional
tumor process,
Oncologic Lymph Node Levels Of The Neck
Level I -
Level II -
Level III -
Level IV -
Level V -
Submental/submandibular nodes
Upper jugular nodes
Middle jugular nodes
Lower jugular nodes
Posterior triangle nodes
The Lymphatic Spread of Tumor is Orderly and Logical
* Lymphatic spread usually occurs first in the
* The most commonly involved node in case of oral and pharyngeal cancer is the
uppermost, then middle and finally the
lower cervical lymph nodes.
subdigastric (juglo-digastric) lymph nodes.
Examination of the Lymph nodes of the Neck
(5)
*Location
*Size(< measured in cm >)
*Tenderness
*Consistency(soft, firm or Hard)
*Mobility(mobile or fixed)
Palpation of the Lymph Nodes of the Neck
* Finding a palpable lymph node is helpful in the management of the
cancer
patient but it is not diagnostic of metastatic tumor.
Occult Metastasis of Primary Tumor to Neck Lymph Nodes
* It is important to be aware of the phenomena of “Occult Metastasis “ of the primary oral
cancer into the Lymph nodes of the neck.
* In this case
you will not be able to detect any lymph node enlargement by routine
clinical and radiographic examination. However, there is microscopic metastasis of the
oral squamous cell carcinoma from the oral cavity into the neck.
Occult Metastasis of Primary Tumor to Neck Lymph Nodes
* In patients with Oral Squamous cell carcinoma, the phenomena of occult metastasis
occurs at rate of
- –% of the floor of mouth lesions
- –% of the tongue lesions
- –% of the gingival lesions
- –% of the tongue lesions
- –% of the lesions of the hard palate
- –% of the lesions of the buccal mucosa
20-35
38-52
17
38-52
22
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Therefore, in order to minimize the risk of tumor recurrence, the surgeons perform a
prophylactic neck dissection to remove some of the most commonly associated lymph
nodes in the neck along with surgical resection of the primary tumor.
Likely sites of involved cervical lymph nodes from the spread of primary
head/neck SCC
Primary Site
(2)
– Lower lip
– Floor of the Mouth
– Posterior mouth
– Oropharynx
Site of Metastasis
(4)
– Submental nodes
– Submental nodes
– Superior jugular/digastric
– Jugulo-digastric chain or retropharyngeal nodes
Radiographic Examination - Panorex
Useful in cases of
bony involvement or to rule out any bony involvement
- Panoramic views shows lytic lesions
C.T.Scan with I.V contrast (Level: From base of skull to clavicles)
C.T Scans help with
precise delineation of the tumor extent and thus provides valuable information
about the size, shape and position of any tumors.
CT Scans with contrast also help reveals
enlarged lymph nodes suggestive of metastatic adenopathy
(seen on C.T.Scan as enhancement of the nodal capsule).
C.T Scans also helps us evaluate adjacent
bony structures and erosions involving the paranasal
sinuses, base of skull and the cervical spine
Magnetic Resonance Imaging (MRI)
* MRI is less commonly used as it is less precise than CT scan in identifying tumor
necrosis and extracapsular spread, but MRI is better in assessing
enlarged lymph
nodes that do not necessarily represent metastasis.
* However, MRI gives a better resolution for soft tissue tumors.
Limitations of C.T.Scan and MRI
- Both C.T.Scan and MRI cannot detect lymph nodes smaller than 1 cm. which, on
occasion, independently of the size, are involved in metastasis (Occult Metastasis)
Management of Oral Cancer
Additional Investigations
(4)
- Bone scan
- PET (Positron Emission Tomography) Scan
- Chest X-ray; if abnormal, then CT Scan of Chest must be examined
- Liver Function test
Bone Scan
* In a patient with squamous cell carcinoma of the oral cavity, it is important to determine the extent of
bone
involvement of the tumor process. Bone scans are highly sensitive in detecting earlier changes in the bone.
- Bone invasion is considered positive when bone scans reveal an asymmetrical or increased activity in the
area of jaw bone which corresponded to the
clinical site of the primary tumor. Thus, they help clinicians
with preoperative evaluation of any evident tumor infiltration of bone.
- Although the Bone scans lack anatomical definition, they are useful in planning treatment for a patient
with
oral cancer planning treatment for a patient with oral cancer.
PET (Positron Emission Tomography) Scan
* PET provides information about the
* Positron emission tomography (PET) has been used to assist in the diagnosis of
* A minimal amount of tumor tissue must be present for the finding to be positive. Thus,
precision of PET is limited to about – mm.
metabolic activity of the tissues.
lymph node
metastasis or spread of tumor to other parts of the body.
5
Purpose and Principles of
TNM Staging System of Malignant Tumors
* Once all clinical and imaging information is collected, the tumor can be accurately staged based
on
AJCC (American Joint Committee on Cancer) -TNM classification.
The — is the most widely used cancer staging system in the world
TNM system
The TNM staging is very useful in facilitating discussion about the
type of malignant tumor that
the patient has between clinicians.
Purpose and Principles of TNM Staging System
Staging looks at the size and depth of the cancer (tumor) and whether it has spread
anywhere else in the body.
As the primary tumor (T) increases in size over time, local invasion occurs followed by
Spread to the regional lymph nodes (N) draining the area of the tumor followed by
Spread to other parts of the body i.e Distant Metastasis (M)
T - the size and depth of the primary tumor
N - whether the cancer has spread to the lymph nodes
M - whether the cancer has spread to another part of the body i.e distant metastases