Fact-sheet: Epidermoid carcinoma of the oral cavity
Updated on 03/28/2019 at 9:40 AM
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Definition
Squamous cell carcinoma of the oral cavity:
- mobile tongue (anterior to the circumvallate papillae)
- floor of the mouth
- glossopelvine sulcus (between the floor of the mouth and the ventral surface of the tongue)
- retromolar trigone
- gingival regions
- vestibules (outside the dental arches, inside the lips)
- labial regions
- buccal regions
Clinical features
Sometimes an incidental finding during examination of the oral cavity.
Mild and subtle presenting signs: a simple discomfort with a sensation of food catching, irritation from a denture or an aggressive decayed tooth, persistent "mucosal inflammation," gingival bleeding, a loose tooth. The persistence and constancy of the sign, its unilaterality, and its consistent localization to the same site should raise concern.
Later, pain on swallowing appears, often accompanied by referred otalgia, foul breath due to frequently associated anaerobic infection, dysphagia, dysarthria, progressive and inexorable limitation of mouth opening or tongue protrusion, and the occurrence of oral bleeding—all findings suggestive of malignancy.
General condition is usually preserved as long as oral intake remains possible.
CT
For the oropharynx and oral cavity, MRI is the reference examination.
CT is sufficient for large tumors that are not amenable to curative treatment.
MRI
Sequences and planes:
– Over the nodal regions: TSE T2 without fat sat, axial
– Over the tumor:
• TSE T2 with fat saturation, axial
• SE T1 without contrast, non-fat sat, axial
• T1 gadolinium fat sat, axial + additional plane depending on location:
– Tonsil and IMC: coronal
– Soft palate: coronal +/- sagittal
– Posterior pharyngeal wall: sagittal
– Tongue base: sagittal
– Mobile tongue and floor of mouth: coronal +/- sagittal
The appearance of the tumor (ulcerated lesion, vegetating...), its level, its volume, and its extent must be specified +++
Management
1) BRACHYTHERAPY OF THE PRIMARY TUMOR
Using iridium-192, brachytherapy is applicable only to certain locations (lips, tongue, anterior floor of mouth). Among the irradiation techniques, it is the most locally effective, but it is contraindicated if the tumor is in contact with bone, since beyond 50 Gy it causes osteonecrosis. This technique is now performed only in a few centers.
2) EXCLUSIVE EXTERNAL BEAM RADIOTHERAPY
Exclusive external beam radiotherapy is used:
● on the primary tumor
● on lymph nodes that are clinically palpable and characterized by CT
3) COMBINED RADIOSURGICAL TREATMENT
Most often, tumor and nodal surgery is followed by external beam radiotherapy to the tumor site and nodal regions, at doses adjusted according to the histological findings of the surgical specimen. If the resection margins are questionable or insufficient, a full dose of exclusive radiotherapy is applied. In case of ongoing progression or recurrence, salvage radiotherapy is used, delivered at full dose. Conversely, surgery may also be used as salvage treatment after failure of exclusive full-dose radiotherapy to the tumor site and nodal regions.
4) CHEMOTHERAPY
There is currently no curative chemotherapy for squamous cell carcinomas of the oral cavity. When administered, it most often currently combines 5-fluorouracil with platinum derivatives (cisplatin and carboplatin).
For the oral cavity, it is used in combination with radiotherapy as a radiosensitizer (concomitant chemoradiotherapy).
5) THERAPEUTIC CHOICE
- Regarding the tumor
● For T1/T2 lesions distant from bony structures: surgery or brachytherapy.
● For T1/T2 lesions close to bone: surgery.
● For T3/T4 lesions: surgery, if locally feasible and "reasonable," followed by external beam radiotherapy (tumor resection generally being considered systematically marginal). In case of surgical contraindication (comorbidity, patient's general condition, to a lesser extent age, patient refusal): external beam radiotherapy alone or concomitant chemoradiotherapy.
- Regarding the nodal regions
● neck dissection if surgery is decided for the primary tumor;
● external beam radiotherapy to the lymphatic drainage areas if external beam radiotherapy of the primary tumor is decided;
● systematic neck dissection in case of brachytherapy of the primary tumor in a N0 neck; however, in case of a palpable lymph node, brachytherapy is generally abandoned in favor of surgery, which treats both the tumor and the nodal regions at the same time.
Differential diagnosis
- Lymphomas,
- Accessory salivary gland tumors (cylindromas)
- Other causes of ulceration: aphthous ulcers, herpes, bullous dermatologic disease, primary syphilis, tuberculosis, cat scratch disease, CMV or histoplasmosis ulceration in immunocompromised patients...