Oral cavity cancer Flashcards
What is the incidence of oral cavity cancer (OCC) in the United States?
∼24,000 cases/yr of OCC in the United States
What % of H&N cancers are OCCs?
OCCs comprise 25%–30% of all H&N cancers.
What are the anatomical borders and of what structures does the OC consist?
Lips, gingiva, upper/lower alveolar ridge, buccal mucosa, retromolar trigone (RMT), hard palate, floor of mouth (FOM), oral tongue.
What is the most and least commonly involved site in OCC?
The lower lip is the most common site (38%), and the buccal mucosa is the least common site (2%). The tongue is involved 22% of the time. (Krolls SO
et al., J Am Dent Assn 1976)
What CNs provide motor and sensory innervation to the oral tongue?
Motor: CN XII
Sensory: CN V3 (lingual branch)
What CNs provide the tongue with taste sensation?
Ant two-thirds of tongue: CN VII (chorda tympani)
Post one-third of tongue: CN IX
Which nerve provides motor innervation to the lips?
The facial nerve (CN VII) provides motor innervation to the lips.
Where is the ant-most border of the OC?
The vermilion border of the lips is the ant-most border of the OC.
Where is the post-most border of the OC?
The hard/soft palate junction superiorly and the circumvallate papillae inferiorly.
What are some premalignant lesions of the OC, and which type has the greatest propensity to progress to invasive cancer?
Erythroplakia (∼30% progression rate) and leukoplakia (4%–18% progression rate)
What are some risk factors that predispose to OCC?
Tobacco and alcohol. Also, betel nut consumption, periodontal Dz, sun exposure (lip).
What are the sup and inf spans of levels II–IV LN chains/levels?
Level II: skull base to bottom of hyoid
Level III: infrahyoid to bottom of cricoid
Level IV: infra-cricoid to clavicles
Where are the levels IA–IB nodes located?
Level IA nodes are submental (space b/t the ant belly of the digastric muscles), and level IB nodes are submandibular (space lat the digastric muscle and mandible).
Where are the levels V–VI nodes located?
Level V nodes are in the post triangle. Level VI nodes are in the central compartment paratracheal/prelaryngeal region.
What is the Delphian node?
The Delphian node is a midline prelaryngeal level VI node.
What is the estimated risk of LN involvement with a T1–T2 primary of the lip, FOM, oral tongue, and buccal mucosa?
The risk of LN involvement is ∼5% for the lip, 20% for the oral tongue, and 10%–20% for the other OC T1–T2 primaries.
What is the estimated risk of LN involvement with a T3–T4 primary of the lip, FOM, oral tongue, and buccal mucosa?
The risk of LN involvement is ∼33% for the lip and 33%–67% for the other OC T3–T4 primaries.
What is the nodal met rate for a T1 vs. T2 lesion of the oral tongue?
The nodal met rate is 14% for T1 tongue lesions and 30% for T2 tongue lesions. (Lindberg R et al., Cancer 1972)
What is the overall and stage-by-stage nodal met rate for FOM lesions?
Overall: 20%–30% T1: 10% T2: 30% T3: 45% T4: >50%
Lesions located where in the OC predispose to bilat LN mets?
Midline and anterolat OC lesions (tongue, FOM) predispose to bilat LN mets.
Which OC cancer has the greatest propensity for LN spread?
Oral tongue cancer has the greatest propensity for LN spread.
What OC subsite is 2nd only to the oral tongue in propensity for nodal spread?
The alveolar ridge/RMT has the 2nd highest propensity for LN spread (3rd highest is FOM).
Can ant oral tongue lesions involve other LN levels without involving level I LNs?
Yes. ∼13% of ant tongue lesions skip the level I LNs. (Byers RM et al., Head Neck 1997)
Which anatomic structure divides the oral tongue from the base of tongue (BOT)?
The circumvallate papillae divide the oral tongue from the BOT.
What is the most common site of minor salivary cancers?
Hard palate
What are common sites of DM for cancers of the OC?
Lungs, bones, and liver
What anatomic structure divides the FOM anteriorly into 2 halves?
The lingual frenulum divides the FOM anteriorly.
Where is the Wharton duct located, and what gland does it drain?
The Wharton duct opens at the ant FOM (midline) and drains the submandibular gland.
From where in the OC do most gingival cancers arise?
Most (80%) gingival cancers arise from the lower gingiva.
Do most lip cancers arise from the upper or lower lip?
Most (∼90%) lip cancers arise from the lower lip.
What are some benign lesions that arise from the lip?
Benign lip lesions include keratoacanthoma, actinic keratosis, hemangiomas, fibromas, HSV, and chancre.
What nodal groups drain the tip of the tongue, the ant tongue, and the post tongue?
Tip of tongue: level IA
Ant tongue: level IB and level III (midjugular)
Post tongue: level IB and level II