CARCINOMA BUCCAL MUCOSA

Dr. Abhilash G JR-3

ANATOMY The buccal mucosa includes the

mucosal surfaces of the cheek and lips from the line of contact of the opposing lips to the pterygomandibular raphe posteriorly.

This extends to the line of attachment of the mucosa of the upper and lower alveolar ridge superiorly and inferiorly.

The muscle of the cheek is the buccinator muscle.

The buccal fat pad is superficial to the fascia covering the buccinator muscle and gives the cheeks a rounded contour.

Branches of the maxillary and mandibular nerves (cranial nerves V2 and V3) provide sensory innervation to the skin, the cheek, and the mucous membranes lining the cheeks.

The facial nerve (cranial nerve VII) provides motor innervation to the muscles of the cheeks and lips.

The lips and cheeks function together as an oral sphincter propelling food into the oral cavity.

If the facial nerve is paralyzed, food tends to accumulate within the cheek along the affected side so that saliva and food dribble out of the corner of the mouth.

CLINICAL PRESENTATION After carcinoma of the lip, oral tongue, floor of the

mouth, and lower gum, carcinoma of the buccal mucosa is the fifth most common carcinoma of the oral cavity.

It is the most common carcinoma of the oral cavity in India, Malaysia, and Taiwan.

It usually occurs in the sixth and seventh decades of life, and is more prevalent in men than in women.

Tobacco and betel nut chewing appear to play an important role in the cause of these tumors.[

Carcinomas of the buccal mucosa often occur in association with pre-existing leukoplakia and tend to have multiple primary sites and recurrence.

Excision of the oral leukoplakia may reduce the subsequent development of carcinoma.

These tumors usually arise in the area adjacent to the lower molars along the occlusal line of the teeth.

Leukoplakia - A chronic white mucosal macule which cannot be scraped off, cannot be given another specific diagnostic name, and does not disappear with removal of potential etiologic factors (excepting tobacco).

4-18% progress to invasive carcinoma

PREMALIGNANT LESIONS

ERYTHROPLAKIA Erythroplakia is the clinical

diagnostic term - A chronic red mucosal macule which cannot be given another specific diagnostic name and cannot be attributed to traumatic, vascular or inflammatory causes, i.e. it is a diagnosis of exclusion.

Higher risk of cancer development (~ 30%)

ORAL SUB MUCOUS FIBROSIS (SMF)

4.5 – 7.5 % progress to oral cancer

Clinically, there are three distinct types: exophytic, ulcerative, and verrucous.

The patient may present with pain or bleeding, trismus, or cervical lymphadenopathy.

Posterior extension may result in involvement of the lingual or dental nerves, which may cause ear pain.

Extension behind the pterygomandibular raphe into the pterygoid muscles or into the buccinator and masseter muscles may cause trismus.

In advanced stages, the tumor may destroy the entire cheek and invade the adjacent bones and the neck. Infection is common and mastication becomes difficult. Death usually occurs as a result of poor nutrition and general debilitation

Symptoms Signs Associates with Ulcer Ulceration/growth Leukoplakia Burning sensation Induration SMF Mild irritation Ankyloglosia Erythroplakia Pain Bleeding ulcer Earache Trismus Bleeding Parotid enlargement

ROUTES OF SPREAD Infiltrating lesions of the buccal mucosa

can invade the buccinator muscle, extend to the buccal fat pad, and invade the subcutaneous tissue.

Carcinomas of the buccal mucosa frequently spread by direct invasion into the gingivobuccal sulcus, the upper and lower alveolar ridges, the hard palate, the maxilla, and the mandible.

Lymph node metastasis occurs in approximately 9% to 31% of the patients during the course of the disease.

The submandibular lymph nodes are most frequently involved; involvement of the upper cervical and the parotid lymph nodes is less common. The risk of subclinical disease is 16%.

Distant metastases are rare, as patients often die of uncontrolled local disease before distant metastases are manifested clinically.

PATHOLOGY >90 % Squamous cell carcinomas

Spectrum of diseases from benign lesions like leukoplakia, lichen planus, SMF to verrucous carcinoma to well differentiated squamous carcinoma

Malignant Minor salivary gland tumors such as Adenoid cystic, Adenocarcinoma, Mucoepidermiod carcinoma (< 10%) are uncommon

Malignant Melanoma, Lymphoma, sarcoma occur rarely.

DIAGNOSTIC WORK UP History & Clinical examination , including head

& neck examination

Clinical staging

Assessment of performance & nutritional status

Investigations for histological diagnosis – Punch Biopsy

Investigations to determine the extent of the disease

OPG/ Dental occlusal view

CT Scan / MRI for extent of disease

EUA

USG for N0 neck in select cases

Routine Investigations CXR Routine blood counts Blood chemistry profile Urinalysis

STAGING

INTENT OF TREATMENT Stage I – IV A : Curative

Stage IV B-C : Palliative

The aim of treatment: Cure Loco regional control Preservation of anatomy & function Reasonable cosmesis Quality of life

Tumor factors Primary site Size Proximity to bone Status of cervical nodes Tumor pathology ( histological type, grade, & depth of

invasion) Patient factors Age General medical conditions Tolerance of treatment Acceptance of expected sequelae of therapy Socioeconomic considerations

TREATMENT ALGORITHM

T1,T2 TUMORS

Primary Surgery : wide excision +/- marginal

mandibulectomy Radiotherapy : Radical external RT/ Brachytherapy Nodes N0 : Observe or

SOHD ( if cheek flap raised , USG suspicious, thick tumor or poor follow up expected) followed by Frozen section, if positive nodes, MND is required.

N+ : MND/RND Post op RT as per guidelines

T3, T4 TUMORS

Surgery + Post op RT or CT-RT

Primary Surgery : Composite resection of the buccal

mucosa with mandible or upper alveolus or overlying skin with reconstruction

Nodes N0 : SOHD followed by FS, if positive nodes,

MND required. N+ : MND/ RND

VERRUCOUS CARCINOMA Management is controversial Perceived risk that the tumor may become

more aggressive if it recurs after RT. Many tumors that recur after treatment are

biologically more aggressive. Therefore, it is reasonable to treat these lesions with irradiation if surgery is not feasible.

Wang reported a series of patients with verrucous carcinoma treated with RT; the results were comparable to those for patients treated for squamous cell carcinoma.

SURGERY

Used as single modality in early disease (Stage I & II )

Combined with post operative adjuvant radiotherapy in advanced disease(Stage III & IV)

Wide excision of tumor in all dimensions with adequate margins & appropriate neck dissection essential for locoregional control of disease

ADVANTAGES OF SURGERY Treatment time is shorter.

The risk of immediate and late radiation sequel are avoided.

Irradiation is reserved for recurrence, which may not be resectable.

Pathological assessment, accurate staging.

Disadvantage: functional & cosmetic impairment, increased morbidity when bilateral neck is addressed.

Modified neck dissection is sufficient treatment for the ipsilateral neck for patients with N1 without PNE.

Radiation therapy is added for

N1 with PNE/LVI N2,N3 stages, for control of contra lateral

subclinical disease For invasion through the capsule of the node, For multiple positive nodes

NECK DISSECTION

RND : superficial & deep cervical fascia with its enclosed LN (level I-V) is removed in continuity of SCM, omohyoid muscle, internal & external jugular veins, spinal accessory N & submandibular gland

MND : is finding more acceptance & preference to RND in managing N0 neck because of severe morbidity related to RND such as, shoulder dysfunction, poor cosmesis, facial edema (level I-V LN)

SOHND : least morbid, provides most satisfactory sampling of the LN at the level I, II, III which are greatest risk

Extended SOHND : level I-IV LN dissection

MANDIBULECTOMY Marginal mandibulectomy: partial-thickness (marginal)

mandibular resection Segmental Mandibulectomy

For small lesions with minimal bone invasion, a short section of mandible is removed in continuity with the tumor (e.g., removal of the mandible from the angle to the mental foramen).

Hemimandibulectomy- Removal of the mandible symphysis to the condyle on one side.

- Major cosmetic and functional loss - Reconstruction is performed with a composite

osteomyocutaneous flap

MARGINAL MANDIBULECTOMY SEGMENTAL MANDIBULECTOMY

HPE REPORTGross pathology1. Morphology2. Location & extent of the tumor / lesion3. Tumor dimensions 4. Distance from various margins of excision5. Nodal dissection

Microscopy1. Histologic type2. Grade3. Extent of disease including depth of infiltration4. Perineural invasion

5. Lymphovascular invasion

6. Bone / Cartilage / Skin / Soft tissue involvement

7. Margins of excision, submucosal spread, In – situ changes

8. Nodal status – no. & size of nodes, perinodal extension & level of nodes

9. Status of cut margins

Miscellaneous features1. In RND/ MND status of internal jugular vein2. Presence of predisposing factors - leukoplakia, SMF3. Dysplasia/ in situ elements

Unresectable Disease

Primary disease Adequate surgical clearance is not achievable Extensive Infra Temporal Fossa involvement Extensive involvement of base skull Extensive soft tissue disease – skin edema / ulceration

Nodal disease Clinically fixed nodes Infiltration of Internal / Common carotid artery Extensive infiltration of prevertebral muscles

IRRADIATION Better functional and cosmetic outcome

Elective irradiation of the lymph nodes can be included with little added morbidity, whereas the surgeon must either observe the neck or proceed with an elective neck dissection (sometimes bilateral depending on the primary site),

The surgical salvage of irradiation failure is probably more likely than the salvage of a surgical failure.

The risk of postoperative complications is avoided

BRACHYTHERAPY Accessible lesions Small (preferably < 3cm ) tumors Well defined borders Lesion away from bone Superficial lesions

Tumors of the anterior two thirds of the buccal mucosa without involvement of gingiva are ideally suited for brachytherapy alone.

INDICATIONS OF POST OP RT Primary: Advanced primary – T3 or T4 Close or positive margins of excision Depth of invasion High grade tumor LVI & PNI

Nodes: Bulky nodal disease N2/N3 Extra nodal extension Multiple level involvement

IRRADIATION TECHNIQUES

T1 and T2 lesions Ipsilateral field arrangement that includes the

primary lesion and the level I and II lymph nodes.

The anterior and superior borders of the field should be at least 2 cm from the borders of the primary tumor. The posterior border should be at the posterior aspect of the spinous processes if the nodes are to be irradiated.

Inferior border is at the thyroid notch.

T3 and T4 lesions

Patients with significant tumor extension toward the midline are treated with parallel opposed fields weighted 3 : 2 toward the side of the lesion.

The low neck is treated with an anterior field with a 6-MV x-ray beam to 50 Gy in 25 fractions once daily

Target Volumes (Postoperative) CTV - postoperative bed + draining

lymphatics include ipsilateral levels Ia/b, II, and III when electively treating. If high-risk disease, or N+, treat ipsilateral levels I to V.

Consider contralateral neck irradiation if primary lesion approaches midline

PTV - as per general principles

RT DOSE

Doses of 66 Gy in 2-Gy fractions for positive margins.

60 Gy in 2-Gy fractions or 59.4 to 63 Gy in 1.8-Gy fractions to high-risk regions.

54 Gy in 1.8-Gy fractions for low-risk regions.

An LAN is often used, treated to either 50 Gy in 2-Gy fractions or 50.4 Gy in 1.8-Gy fractions.

Interstitial implants with iridium wires or seeds in nylon ribbons can be considered for treatment of early, small lesions that have not invaded the buccogingival sulcus, the gingiva, or bone.

Usually a minimum tumor dose of 60 to 70 Gy in 5 to 8 days is delivered through a single-plane or double-plane implant on the thickness of the lesion.

The buccal mucosa tolerates high-dose RT with a low risk of late complications.

Trismus may develop if the muscles of mastication receive high doses of irradiation.

CHEMOTHERAPY

Cisplatin - Used in NACT (T4b and N3 cases)

- Used in CTRT

THANK YOU