09/24/2017

ORAL CANCE

By Dr.Narumalar MBBS., DGO, MS - General Surgery - Sun Mar 06, 11:44 am

Current Management of Oral Cancer

Anatomy

Vermilion to junction of hard and soft palate superiorly.
Inferiorly to circumvallate papillae.

Structures: Lips, alveolar ridges, buccal mucosa, retromolar trigone, hard palate, floor of mouth, mobile tongue.

Functions: Speech, mastication, bolus preparation and initiation of deglutition.

Oral Cancer:
 Female : Male ratio 1 : 2
 Age 45-60 yrs

Carcinogenesis:

 Mutations or deletions that include chromosome 9p, 3p, 17p (Mutation or loss of p53)
 Mutations on chromosomes 11, 14, 13, 6 and 8 – over expression of cyclin D1 protein
 Proto oncogenes studied in head and neck cancers are cyclin D1, VEGF, TGFﻊ, TGFβ, EGF-R
 P16 –ARF Gene locus is altered
 3-7 % incidence of secondary lesion in upper aerodigestive tract, oesophagus or lung.

ETIOLOGY

 Smoking – tobacco
 Spices
 Sharp tooth
 Syphilis
 Spirits
 Supari
 Sepsis
 Submucous fibrosis
 Viruses – herpes, HPV 16 & 18
 Poor nutrition – deficiency of Vit. A & C.

Premalignant lesions:

 Leucoplakia
 Erythroplakia
 Submucous fibrosis

Types:

 Ulcerative
 Exophytic
 Infiltrative
 Verrucous
 Any ulcer present for more than 2 weeks without signs of regression – suspect malignancy.

Clinical features

 Ulcer
 Bleeding
 Numb tongue
 Deviation of tongue
 Nasal block, numb cheek, bleeding nose, loosening of teeth
 Alteration of voice
 Horners syndrome
 Family history of Gorlingoltz syndrome

Regional Nodes:

 Oral cancers spreads to submental, submandibular, deep cervical and retropharyngeal nodes

Investigations:

 X-Ray : Panaromic view + Occlusal view of mandible
 Panaromic view + Occlusal view of maxilla
 X-Ray chest PA view
 Ultrasound abdomen
 CT Scan
 MRI
 PET Scan
 Biopsy – Incisional, excisional
 Direct laryngoscopy
 Bronchoscopy
 Upper GI endoscopy
 Serum tumour markers – alkaline phosphatase, serum Calcium

TNM Classification

 T1 –Tumour <2cm diameter
 T2 – Tumour between 2 and 4 cm
 T3 – Tumour > 4cm
 T4 – Tumour invading into adjascent structures, e.g. muscle, bone
 N0 – No regional lymphnode metastasis
 N1 – Metastasis in single ipsilateral node ≤ 3cm
 N2a – Metastasis in single ipsilateral node >3, <6 cm
 N2b – Metatstasis in multiple ipsilateral nodes <6 cm
 N2c – Metastasis in bilateral or contralateral lymph node <6cm
 N3 – Metastasis in a lymph node more than 6 cm
 M0 – No distant metastasis
 M1 – distant metastasis
 Stage 0 – Tis N0 M0
 Stage 1 – T1 N0 M0
 Stage 2 – T2 N0 M0
 Stage 3 – T3 N0 M0, T1T2T3 N1 M0
 Stage 4 – T4 N0 M0, any T, any N, M1

Treatment of oral cancer

 Early stage disease I & II – Surgery or Radiation
 Late stage disease III & IV – Surgery and Radiation or chemotherapy

Radiotherapy:

 Brachytherapy – Implantation of radium needle, radioactive tantalum wires or 192 iridium wires – kept for 9 to 10 days
 Teletherapy – External beam radiation with telecobalt or linear acclerator – 6000 cGY 5 to 6 weeks
 IMRT – Intensity Modulated Radiation Therapy: Advanced form of three diamensional conformal radiation therapy that reduces photon dosage to surrounding normal tissues
 Hyperfractionation and Acclerated fractionation – Administering radiation in higher doses or more frequent doses than conventional radiation therapy
 Radiation not effective for large volume, low grade neoplasms or tumours in close proximity to mandible
 If index tumour is treated with radiation and neck is N0 or N1 – Nodes are treated with irradiation

Complications of Radiotherapy:

 Mucositis
 Xerostomia
 Loss of taste
 Infection – Especially candidial
 Dental caries
 Osteo radio necrosis

Surgical Treatment

 Early stage disease – Wide local excision and primary closure
 If defect is large, SSG can be sutured and quilted in place
 Advanced Stage disease – For adequate exposure – Mandibulotomy through a lip splitting incision. Alternatively, a visor flap avoiding a lip splitting incision can be made.

Carcinoma Lip:

 Defects involving upto 1/4th of the lip – closed primarily in three layers – mucosa, muscle and skin
 Defects involving 1/4th to ½ of lip – abbe flap for midline defects
 Abbe – Estlander flap for designing oral commissure
 Naso labial flaps for small lateral defects
 Defects more than ½ of lip – for near total loss Karapandzic flaps, cheek advancement flap, gilles fanflaps

Carcinoma Tongue:

 Small tumours – wide local excision and primary closure or closure by secondary intention
 Excision of large tumours – partial or hemiglossectomy
 Preferred reconstruction – radial forearm free flap
 Lateral arm free flap can be used for anterior tongue reconstruction
 A palatal augmentation prosthesis may assist for speech and food propulsion

Radial forearm free flap:

 Reliable, thin, pliable and sensate
 Skin from the antecubital fossa to flexor crease of wrist can be harvested
 Depends on 9-17 fascial branches of radial artery
 Lateral antebrachial cutaneous nerves is harvested along with the flap
 Cephalic vein is also harvested

Carcinoma of floor of mouth:

 Treatment is primarily surgical with excision of involved tongue or mandible to obtain negative margins
 Commando or composite resection
 Smaller defects – SSG from lateral thigh
 Moderate defects involving larger portion of mylohyoid – nasolabial flap, fascial artery musculomucosal flap, forehead flap.
 Local flaps for soft tissue reconstruction – the platysmal and submental myocutaneous pedicled flaps
 For large defects – free flaps

Carcinoma alveolus:
 Tumours that abut the periosteum of the mandible – resect along with adjacent periosteum only
 Tumours adherent to the periosteum, minimal cortical mandibular invasion – excision with marginal mandibulectomy
 Gross invasion of tumour and involvement of inferior alveolar canal – segmental mandibulectomy

Mandibular reconstruction techniques:

 Soft tissue coverage of mandibular reconstruction plates
 Non-vascularized bone grafts
 Vascularised bone flaps

Free flaps:

 Fibular osteocutaneous free flap
 Scapular osteocutaneous free flap
 Iliac crest osteocutaneous free flap
 Radial fore arm osteocutaneous free flap
 Lattismus dorsiserratus rib free flap

Osseointegrated implants:

 Direct anchorage of the implant, e.g. titanium to the bone and the formation of bone on the implant surface
 Supports implant borne dentures facilitates post reconstruction
 Dental rehabilitation
 Placed in one or two stage procedure
 Initial fixtures placed in neomandible allowing 12 weeks for healing
 Implants fitted with transmucosal abutments
 Final soft tissue modifications made and dental prosthesis placed.

Carcinoma buccal mucosa:

 Buccal Cavity Reconstruction
 Small defects– primary closure possible
 Larger superficial defects:
– Quilted skin/mucosal grafts
– Temporoparietal fascial flap (STSG for lining)
 Large full thickness defects:
– Pectoralis major myocutaneous flap Latissimus dorsi myocutaneous flap
– Deep invasion – through and through excision of skin necessiating internal and external lining by fasciocutaneous free flap

Carcinoma palate:

 For progressively destructive tumours – inferior maxillectomy, subtotal maxillectomy, total maxillectomy
 Reconstruction with soft tissue flap – for small defects
 Obturation with dental prosthesis for defects with some remaining palate
 For extensive palatal resection, bony free tissue transfer

Chemotherapy:

 Usually combined with radiation therapy
 Currently used agents are: Cisplatin, Carboplatin, 5-Fluro urasil and taxanes (paclitaxel and docetaxeal)
 Intra arterial delivery increases drug dose to the tumour and decreases toxicity

Indications:

 Poor prognosis stage IV cancer
 Unresectable stage IV disease
 Protocols for organ preservation – larynx, base of tongue, oropharynx and nasopharynx

Comprehensive dental treatment

 Patients prior to chemoradiation should have unsalvageable teeth removed, periodental health maximised and fluoride therapy instituted
 Osteoradio necrosis requires tooth extraction after radio therapy
 Hyperbaric oxygen therapy reverses radiation induced tissue damage
 For osteoradio necrosis, frequently mandibular resection and reconstruction are required

Emerging therapies – new horizons

 Positron emission tomography – recurrent cancer
 Sentinel node biopsy
 Role of surgery for distant metastasis – pulmonary
 Reirradiation in head and neck cancer

New directions in experimental therapy
 Role of molecular markers – provides prognostic data, selection of useful therapeutic modalities, provides target for specific therapy i.e. gene therapy
 Immunotherapy with interleukin -2
 Biological targeted therapies
– monoclonal antibodies against epidermal growth factor
receptor
– CDK (Cyclin Dependent Kinase) inhibitors Flavopiridol
– Intra lesional injection of E1b – deleted adeno virus
ONYX- 015 (adenovirus transfected P53 Gene), causes
tumour cell necrosis and improvement in tumour related symptoms.

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