Caving-in on oral cancer

Oral cavity cancer is a potentially preventable condition due to its relationship with familiar risk factors and easy detectability, write Dr Girish S Shetkar

Oral cancer is the sixth most common cancer worldwide with India contributing to one-third of the total burden. Every year, globally more than 3,50,000 new cases are diagnosed and 1,77,000 deaths occur, though with significant geographic and risk factor variations. In India, every year around 1,36,000 new cases and about 57,000 deaths are reported. Oral cancer is the most common cancer in India, accounting for over 30% of all cancers. We are on the brink of an oral cancer epidemic.

A majority (60-80%) of oral cancer patients present at an advanced stage, which would have a significant impact on cure rates, important functions like chewing, swallowing, speech and breathing, the cosmesis, and lastly the increased costs of treatment.

Oral squamous cell carcinomas (OSCC) contributes over 90% of all oral cancers and the term oral cancer is applied as synonymous with OSCC. Oral cancer commonly arises from potentially malignant lesions (earlier known as ‘pre-cancer’ or ‘pre-malignant’) such as oral submucous fibrosis, leukoplakia (whitish patch), erythroplakia (reddish patch), oral lichen planus (a chronic inflammatory autoimmune disease), proliferative verrucous leukoplakia which is the commonest and are currently known as oral potentially malignant disorders (OPMDs). The early detection and management of OPMDs are necessary to minimise or even eliminate the risk of transformation into oral cancer.

The oral cavity includes the lips, buccal mucosa, gums, oral tongue, the floor of the mouth, upper and lower jawbones, and hard palate — oral cancer or OPMDs can occur at any of these subsites.

The important causative factors for oral cancer are:

Tobacco consumption in any form: Smoked tobacco — beedis, cigarettes, hookah, cigars, E-cigarettes, smokeless/chewable tobacco — pan masala, gutkha, paan/betel quid, betel nut, khaini, mishri, mawa, kharra, zarda, snuff.

Alcohol use.

Poor oral hygiene.

Sharp tooth or an ill-fitting denture causing chronic irritation to the oral mucosa.

A diet low in fresh fruit and vegetable intake. About 85-90% of oral cancers are related to tobacco and alcohol use, which are the two most important risk factors. As per the Global Adult Tobacco Survey India (2009-10), 35% of the adult population in the country consume tobacco in one form or the other.

Signs & symptoms of oral cancer/OPMDs:

White, or red patch in the mouth.

Persistent or non-healing sores or ulcers in the mouth for > 2-3 weeks.

Swellings or lumps on lips, gums, or other areas inside the mouth, and in the neck.

Unexplained numbness, loss of sensation, or pain in any area of face, mouth or neck.

Difficulty in chewing or swallowing.

Dentures not fitting or becoming uncomfortable.

Difficulty in moving the tongue or progressively decreased mouth opening.

Diagnosis: Oral cancer is detected by:

A proper physical examination of the mouth and neck regions to check for any suspicious changes in the oral cavity, and enlarged/significant lymph nodes in the neck.

A biopsy (incisional/punch) is the gold standard for diagnosing oral cancer. A tissue sample is taken from the most representative portion of the suspicious oral lesion and sent for histopathological examination.

Imaging — the commonly used imaging techniques are computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) CT scan. Once the disease extension and staging is confirmed, the patient is prepared for definitive curative-intent treatment.

Treatment: Surgery is the mainstay for curable oral cancer. It involves a few standard procedures.

Removal of cancerous growth and involved structures in the oral cavity with proper margins.

Removal of the same side neck lymph nodes with a potential for harbouring disease.

An appropriate reconstructive procedure by using skin, muscle, or bone-in different combinations from other parts of the body to cover the defect and achieve better functional and aesthetic results.

Surgery alone would suffice in early-stage (Stage I & II) cancer treatment. But, for advanced stages (Stage III & IV), multi-disciplinary management involving upfront surgery, followed by either radiation or chemoradiation will be required as part of the curative treatment.

Post-treatment follow-up: The post-treatment surveillance of oral cancer patients by clinical assessment, baseline and annual imaging would aid in early detection of any recurrence or a new primary cancer (especially due to the field cancerisation changes seen in oral cancer patients — prolonged exposure to carcinogens, usually tobacco, results in multifocal areas of precancerous changes at various rates within the entire field).

Routine surveillance can also facilitate multidisciplinary care involving a speech and swallowing therapist, dentist, physiotherapist, psycho-oncologist, and dietitian.

The post-treatment monitoring and follow-up would also help to detect and manage late complications if any.

By early diagnosis and proper treatment of oral cancer, the cure rates can be as high as 85-90%. It would also significantly lower the cost and improve the functional and cosmetic outcomes associated with treatment, thereby better quality of life for patients.

(The author is a consultant in head & neck oncology.)