Carcinoma of Oral Cavity

CARCINOMA OF ORAL CAVITY
  • It is the most common cancer in males in India.
SITE OF ORAL CARCINOMA
  • The most common type of oral cancer in India is buccal mucosa (38%) followed by anterior tongue secondly (16%) and thirdly lower alveolus (15.7%). So when the percentages of buccal mucosa and lower alveolus are combined it is alveobuccal complex (53.7%), the most common type of oral cancer in India. The"coffin corner" at the posterior tongue/floor of the mouth is a common site for cancer but may be missed
  • Worldwide the most common type of oral cancer is the carcinoma of the lip and secondly carcinoma of the tongue.
  • Base of Tongue and soft palate are not included in Oral cavity cancer(thet are included in Oropharyngeal carcinoma)
HISTOLOGICAL TYPE OF ORAL CARCINOMA
  • M/C variety of buccal cancer is squamous cell cancer.
  • Verrucous carcinoma is a variety of well-differentiated squamous cell carcinoma which is locally aggressive involving the bone but lymph node metastasis is uncommon.Presents as large,fungating,soft,papillary lesion in the mouth. Histologically show marked hyperkeratosis and acanthosis with dysplasia limited to deeper layers. Repeated biopsies report it as squamous papilloma.
ETIOLOGY OF ORAL CARCINOMA
  • The etiology of SCC appears to be multifactorial and strongly related to lifestyle, mostly habits and diet (particularly tobacco alone or in betel, smoking and alcohol use). Candida albicans and viruses, such as herpes viruses and papillomaviruses,Syphillis may be implicated in some cases
  • Immune defects or immunosuppression, defects of carcinogen metabolism, or defects in DNA-repair enzymes(involvement of tumor suppressor genes (TSGs), particularly in chromosomes 3, 9, 11, and 17) underlie some cases of SCC.
  • Sunlight exposure predisposes to lip cancer.
CLINICAL FEATURES OF ORAL CARCINOMA
  • Initial symptoms include sore throat, bleeding, dysphagia and odynophagia, referred otalgia(from trigeminal nerve), and voice changes, including a muffled quality or hot potato voice
  • Trismus indicates advanced disease - results from involvement of the pterygoid musculature.
  • Spread is local, especially through muscle and bone
  • Incidence of cervical metastasis in head and neck cancers (in decreasing order).Metastases to distant sites are uncommon.
  1. Tongue (most common)
  2. Floor of mouth
  3. Lower alveolus
  4. Buccal mucosa
  5. Upper alveolus
  6. Hard palate
  • In Hard palate cancers lymph node metastasis is least common.
  • Second primary tumor of head and neck is most commonly seen in malignancy of Oral cavity.
PREMALIGNANT LESIONS OF ORAL CAVITY
  • Leukoplakia is the most common premalignant lesions. But, the risk of malignant transformation of erythroplakia is 17 times higher than that seen with leukoplakia.
  • The most common predisposing factor for both these conditions is smoking.
  • Erythroplakia is a red patch or plaque on the mucosal surface. The red colour is due to decreased keratinization, and as a result the red vascular connective tissue of the submucosa shines through.
  • Treatment is excision biopsy and follow up.

High risk Medium risk Equivocal risk
Leukoplakia
Erythroplakia
Chronic hyperplastic candidiasis
Oral submucosal fibrosis
Syphilitic glossitis
Sideropenic dysphagia
Oral lichen planus
Dyskeratosis congenita
Discoid lupus erythematosu
INVESTIGATIONS IN A CASE OF ORAL CARCINOMA
  • Biopsy of the ulcer or growth and lymph node.
  • Pan endoscopy
  • Chest X ray: may be indicated because the lungs are the most common site for metastases and a site for second primary carcinomas.
  • CT scan of Head and neck:to evaluate primary tumor,its extension in the lymph nodes and surrounding mandibular bone.
  • MRI of Head and neck:to evaluate soft tissue involvement.
TNM STAGING OF ORAL CARCINOMA
  • Primary tumor, as follows:
  • T0 - No primary tumor
  • Tis - Carcinoma in situ
  • T1 - Tumor 2 cm or smaller
  • T2 - Tumor 4 cm or smaller
  • T3 - Tumor larger than 4 cm
  • T4 - Tumor larger than 4 cm and deep invasion to muscle, bone, or deep structures (eg, antrum)
Lymphatic node involvement, as follows:
  • N0: No regional lymph node metastasis
  • N1: Metastasis in a single ipsilateral lymph node
  • N2a: Metastasis in a single ipsilateral lymph node >3 cm but not > 6 cm
  • N2b: Metastasis in multiple ipsilateral lymph nodes, none >6 cm in greatest dimension
  • N2c: Metastasis in bilateral or contralateral lymph nodes, none >6 cm in greatest dimension
  • N3: Metastasis in any lymph node >6 cm
Tumor metastasis(M), as follows:
  • M0 - No metastasis
  • M1 - Metastasis noted
Staging
  1. Stage I : T1, N0, M0.
  2. Stage II : T2, N0, M0.
  3. Stage III :
  • T3, N0, M0
  • T1, T2, T3, N1, M0
Stage IV :
  • T4, N0, M0
  • Any T, N2 or N3, M0
  • Any T, any N, any M
TREATMENT OF ORAL CARCINOMA
  • Treatment involves both surgery and/or radiotherapy (& chemotherapy for advanced lesions).
  • Ablative surgery ideally excises the cancer with at least a 2-cm margin of clinically normal tissue.
  • If at least 1 node has clinical signs of invasion, a reasonable presumption is that others may be involved and must be removed by traditional radical neck dissection. Functional neck dissections (modified to preserve the jugular, sternomastoid, or accessory nerve, while ensuring complete removal of involved nodes) have gained popularity. Moderate dose radiotherapy may be given in a patient with lymph node metastasis.
  1. Longer-term complications of radiotherapy, such as dry mouth (xerostomia), loss of taste, osteoradionecrosis (ORN) (less commonly).
  2. Specific complications from the surgery of OSCC may include infection and rupture of the carotid artery, salivary fistulae, and thoracic duct leakage (chylorrhea). Trismus in oral cancer patients is severe in those treated with Surgery and Radiotherapy.
  • Reconstruction :Free flaps/Pedicle flaps/Hard tissue.
  • Abbey-Estlander flap is used in the reconstruction of Lip.
PROGNOSIS OF ORAL CARCINOMA
  • Oral malignancy with best prognosis is carcinoma lips.
  • Oral cancer with worst prognosis is floor of mouth carcinoma.
Exam Question
  • Referred otalgia can be due to Carcinoma oral cavity.
  • In Hard palate cancers lymph node metastasis is least common.
  • Probable diagnosis in a patient chewing tobacco for the past 50 years presenting with a six months history of a large, fungating, soft papillary lesions in the oral cavity penetrating into the mandible,Lymph nodes not palpable and biopsy showing benign appearing papillomatosis with hyperkeratosis and acanthosis infiltrating the subjacent tissues is Verrucous carcinoma.
  • Alveobuccal complex is the commonest site of oral cancer among Indian population.
  • Abbey-Estlander flap is used in the reconstruction of Lip.
  • Malignant potential for erythroplakia is 17 times higher than in leukoplakia.
  • Erythroplakia is a red patch or plaque on the mucosal surface. The red colour is due to decreased keratinization.
  • The most common pre-malignant condition of oral carcinoma is Leukoplakia.
  • Erythroplakia,Leukoplakia, Submucosal fibrosis predisposes to oral cancer.
  • Lichen Planus does not predispose to Oral Carcinoma.
  • Oral Carcinoma:Systemic Metastasis is un-common and responds to Radiotherapy.
  • Predisposing factors for development of oral carcinoma are Smoking,Alcohol, Syphilis.
  • Commonest cancer of the oral cavity is Squamous cell carcinoma.
  • Trismus in oral cancer patients is severe in those treated with Surgery and Radiotherapy.
  • Ca. Lip. has best prognosis.
  • Second primary tumor of head and neck is most commonly seen in malignancy of Oral cavity.
  • Base of tongue and soft palate is not included in oral cavity carcinoma.
  • 3 cm oral cavity tumor with single ipsilateral 5 cm lymph node with no distant metastases; stage of tumor is T2N2aM0.
  • Most common cancer in males in India is Ca oral cavity.
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