Risk Factors And Treatment For Oral Cancer

Risk Factors And Treatment Modalities For Oral Cancer

Risk Factors oral cancer

Risk factors are habits, aspects of lifestyle and chronic health problems that increase the likelihood of developing a disease. For oral cancer following are the risk factors:

General

• Gender: Oral cancer is twice as common in men as in women. This difference may be related to the use of alcohol and tobacco, a major oral cancer risk factor that is seen more commonly in men than women. According to the American Cancer Society, the gender difference is decreasing among oral cancer patients as more women are using tobacco and drinking.
• Age: The average age at diagnosis for oral cancer is 62, and two-thirds of individuals with this disease are over age 55.
• Ultraviolet light: Cancers of the lip are more common among people who work outdoors or others with prolonged exposure to sunlight.
• Poor nutrition: Studies have found a link between diets low in fruits and vegetables and an increased oral cancer risk.

Genetics oral cancer

• Genetic syndromes: Some inherited genetic mutations, which cause different syndromes in the body, carry a high risk of oral cancer. These include:
• Fanconi anemia: This blood condition is caused by inherited abnormalities in several genes. Problems can begin at an early age and often lead to leukemia or aplastic anemia. The risk of oral cancer among people with Fanconi anemia is up to 500 times higher than among the general population.
• Dyskeratosis congenita: This genetically linked syndrome can also cause aplastic anemia, and carries a very high-risk of oral cancer occurring at an early age.

oral cancer Lifestyle

• Tobacco use: About 80% of people with oral cancers use tobacco in the form of cigarettes, chewing tobacco or snuff. The risk of developing oral cancer depends on the duration and frequency of tobacco use. Smoking can lead to cancer in the mouth or throat, and oral tobacco products are associated with cancer in the cheeks, gums, and inner surface of the lips.
• Alcohol: About 70% of people diagnosed with oral cancer are heavy drinkers. This risk is higher for people who use both alcohol and tobacco. For people who smoke and drink heavily, the risk of oral cancer may be as high as 100% more than the risk for people who do not smoke or drink.
• Betel quid: Many people in Southeast Asia, South Asia, and others parts of the world chew betel quid, a leaf from the betel plant wrapped around areca nut and lime. Chewing gutka, a combination of betel quid and tobacco, is also common. Both of these substances are associated with an increased oral cancer risks.

Other Conditions oral cancer

• Human papillomavirus (HPV) infection: Human papilloma viruses, or HPV, include about 100 similar viruses. Many HPVs cause warts, but some are involved in cancer. Most noteworthy, HPV is tied to the development of cervical cancer. HPV is also a risk factor for oral cancers. About 25 % of patients with these cancers are infected with the same HPVs as are seen in with cervical cancer. In particular, there is a strong link between HPV-16 and oral cancer. People with oral cancers linked to HPV tend to not be smokers or drinkers, and usually have a good prognosis. Typically, HPV infections in the mouth and throat do not produce any symptoms, and only a small percentage of these infections develop into cancer.
• Immune system suppression: Taking drugs that suppress the immune system, such as those used to prevent rejection of a transplant organ or to treat certain immune diseases, may increase the risk of oral cancer.
• Lichen planus: People with a severe case of this illness, which usually causes an itchy rash but sometimes appears as white lines or spots in the mouth and throat, may have a higher risk of oral cancer. Lichen planus usually affects middle-aged people.
• Graft-versus-host disease (GVHD): This condition can occur after a stem-cell transplant, in which bone marrow is replaced following cancer occurrence or treatment. The new stem cells may have an immune response against the patient’s own cells, and tissues in the body may be destroyed as a result. GVHD increases the likelihood of oral cancer, which can develop as soon as 2 years later.

Treatment Modalities for Oral Cancer

Main treatment modalities for oral cancer are surgery, chemotherapy and radiotherapy or the combination of these procedures.

Various other new therapies are also developed in modern era to treat the oral cancer, i.e. photodynamic therapy, intensity modulated radiation therapy, gene therapy, intra lesional chemotherapy, intra-arterial chemotherapy, immunotherapy and last but not the least cancer vaccines.

Surgery for Oral Cancer

Surgical treatment in aspect of oral cancer should be excision of the lesion.

Oral cancer should be excised by leaving the proper adequate margins of normal tissue, so that residual tumor cell should not remain in the surgical field. Following are the surgeries:

• Enbloc Resection: In this procedure, complete tumor is removed with proper adequate margins of normal tissue. Localized tumor without suspected cervical lymphatic involvements is treated by this method.
• Radical neck resection: In this, the local lesions with a suspected cervical lymph node involvement undergoes a wide resection of primary tumor along with the dissection of the involved part of neck.
• Commando Operation: In this, en bloc resection of primary tumor is done along with the involved osseous structures and it is combined with radical neck resection.

Palliative Treatment oral cancer

Oral cancers which should not be resectable in them debulking or deliberate subtotal removal of tumor is carried out. This leads to pain relief. Only advantage of the treatment is that patient’s quality of life is improved.

Reconstruction

This is done to repair the cosmetic defect and to reestablish the function of the lost tissue.

Radiotherapy oral cancer

Radiation is delivered by three principle methods, i.e.

Teletherapy: In which beam from external source is directed towards a tumor.

Interstital brachy therapy: In which, the radioactive source is placed on or within the body.

Intraoperative brachy therapy: In which radioactive material may be placed in the operating room while the wound is still open after surgical removal of cancer mass.

Chemotherapy oral cancer

• It is used in the treatment of malignant tumor. It selectively kill’s tumor cells by virtue of cell kinetic proliferation character and cell biology.
• It produces only partial or temporary tumor regression.
• It may be used in combination with radiotherapy or surgery or as palliative treatment.

Drugs used are methotrexate, cisplatin, vincristine, bleomycin, adriamycin. Often it is given intra-arterially through external carotid artery using arterial pump or by increasing the height of the drip more than l3 feet, so as to attain a pressure more than systolic pressure. Chemotherapy can also be given IV or orally postoperatively.

New Modalities of Treatment of Oral Cancer

Oral Cancer – Photodynamic Therapy

• It was introduced by Von Tappener and Jadlbaner in 1904.
• Principle of the therapy is selective uptake as well as retention of administered photosensitizer in tumor which is followed by irradiation with LASER. This causes necrosis of tumor due to origin of singlet oxygen.
• Photosensitizing agent used is porphyrin.

Method oral cancer

• Photosensitizing agent, i.e. porphyrin is injected, i.e. 2 mg/ kg in blood.
• Porphyrin comes in contact with all the blood cells, but its contact is more with tumor cells.
• After 48 hours of infusion of porphyrin, LASER of wavelength 628–635 leads to activation of tumor at an interval of 3 to 6 hours.
• Wavelength emitted by LASER is absorbed by porphyrins and there is production of oxygen.
• Produced oxygen destroys cancer cells and blood vessels.

Intralesional and Intra-arterial Chemotherapy

• In intralesional chemotherapy, drug is inserted in the tumor. Drug remains till the tumor and does not spread to other normal tissues. This decreases the adverse effects of drug.
• In intra-arterial chemotherapy, drug is inserted into the arteries which supplies to the tumor.
• Intensity Modulated Radiation Therapy
• It is also known as tomotherapy.
• In this method software passes a radiation beam to the area of tumor.
• It decreases adverse effects of drug to the normal and healthy tissue.

Gene Therapy oral cancer

In this method, in which functional genetic material is inserted into the target cells for replacing defective gene.

Immunotherapy

This method leads to the stimulation, repairing and also enhances the body’s immune response. This is done by following methods, i.e. immunologic gene therapy and radioimmunotherapy.

Cancer Vaccines oral cancer

• They are of two types, i.e. therapeutic vaccines and preventive/prophylactic vaccines.
• Therapeutic vaccines: It helps in the treatment of cancer by blocking the growth of existing cells and also prevents recurrence. It consists of adjuvant vaccines, DNA vaccines, whole cell tumor vaccine, etc.
• Preventive/prophylactic vaccines: They provide protection against the virus which leads to cancer.