31st May is widely recognised as the World No Tobacco Day. While this has to be a continuous effort, it is still a good idea to use this time of the year to increase our awareness about the most dangerous side effect of tobacco chewing, i.e Oral Cancer, its causes & prevalence in India and also some of the basic yet critical steps to give us the best chance of beating it. 
Today, oral cancer is the sixth most common type of cancer worldwide with India contributing to almost one-third of the total numbers. It is estimated that oral cancer constitutes close to 30% of all cancers in India making it easily the most common cancer in India.
India also has the unwanted distinction of being among the top three countries to have the highest number of oral cancer cases. Oral squamous cell carcinoma (OSCC) is the most common type of oral malignancy which unfortunately has a high mortality rate as well. 
Oral cancer is an extremely important health issue in our country as it is one of the most common types of cancer affecting a large population. It is the low-income population which is most vulnerable due to high exposure to the various risk factors as well as lack of knowledge regarding most of these.  Low social economic class is associated with factors like lack of adequate nutrition, access to health care facilities, poor sanitary & hygiene conditions and lack of awareness about the key risk factors of oral cancer. Most of the population in our country are not fortunate enough to have access to an organized and regulated cancer care system. A diagnosis of cancer often leads to prohibitively high personal health expenditures which can be damaging for the entire family, often throwing off the complete financial stability of not only the patient but his / her immediate family as well.

Key Causes of Oral Cancer
Fortunately, unlike some other cancers, there are certain behaviours or habits that clearly puts one at greater risk of contracting Oral Cancer.  Some of these are:

• Use of Tobacco – As mentioned in the start of this article, tobacco usage is probably the most well-known and widely advertised cause of Oral Cancer is consumption of different forms of Tobacco which includes factory made cigarettes, cigars & loose tobacco which is smoked in pipes and is the key component of handmade cigarettes.
• Smokeless tobacco (SLT) is acknowledged as one of the biggest risk factors for oral cancer. A widely followed practice in India is consumption of tobacco without combustion. The tobacco is placed in contact with mucous membranes of the user(s) through which the nicotine is absorbed.   SLT is consumed in multiple ways varying from chewing tobacco not mixed with any other ingredient to a mixture of tobacco with other ingredients such as in betel quid, areca nut with tobacco, Naswar, paan-masala with tobacco, Gutkha, Khaini, and Mishri to name a few.  Smokeless tobacco contains around 28 known carcinogens making it one of the most deadly risk factors for Oral Cancer.
• Alcohol – Consumption of alcohol is another important risk factor for oral cancer. The risk associated with alcohol increases with number of drinks consumed in a week, and should ideally be limited to 1-2 drinks per day. As per some studies, alcohol consumption significantly increases the probability of contracting oral cancer both among current users and past drinkers. 
• Oral Hygiene- Poor oral hygiene is yet another cause of oral cancer. In one study, more than 85% of oral cancer patients had poor oral hygiene. Poor oral hygiene related attributable risk is lesser for men and significantly higher for women in India. People who have been wearing dentures for more than 15 years and not visiting a dentist regularly is a segment with a very high risk of suffering from Oral cancer
• Diet- The role of diet takes special importance in countries like India, which are fast moving towards industrialization and westernization. We have historically had a predominantly plant-based diet and with the growing influence of western life style we are moving towards a diet rich in animal proteins. When we consider this in conjunction with other harmful habits like smoking and alcohol, the effect would be an increase in the chronic disease burden especially cancer
• Human papillomavirus (HPV)—HPV 16 is one of the other leading causes of Oral cancer. HPV is known to infect the mouth and throat and cause cancers of the oropharynx (back of the throat, including the base of the tongue and tonsils). HPV is believed to be the main cause of oropharyngeal cancers

Preventive measures

• DO NOT consume any type of tobacco product either by SMOKING OR CHEWING. If you are a smoker, even casually, decide to stop NOW. It is not enough to reduce your tobacco intake; this has to stop completely.  It is vital to Say NO to Tobacco in any form if we are to fight Oral Cancer
• Improvement in Oral Hygiene - Even though this seems basic, it is important to thoroughly brush and floss your teeth regularly. An unhealthy mouth compromises the immunity and adversely affects the body’s ability to fight off potential cancers.
• Consume Alcohol only in moderation (One to two drinks per day) and r never binge drink. The risk of developing oral cancer has a direct correlation with the amount and length of time alcohol and tobacco products are used.
• Limit your exposure to the sun. It is very important and yet often ignored. Please be mindful of using UV-A/B-blocking sun protection on the lips during exposure to the sun. Repeated & prolonged exposure to the sun enhances the risk of cancer on the lips. There are a lot of easily available sunscreen tubes to for everyday use. 
• Exercise regularly. This is yet another habit that will hold you in good stead for a number of health-related issues. An active lifestyle, amongst other benefits is known to boost the immune system and help to protect the body against multiple ailments including cancer.
• Diet – The diet should be rich in cruciferous vegetables like (like cabbage and broccoli), beans, berries, leafy vegetables, flaxseed, garlic, grapes, green tea, soy and tomatoes as these foods are known for their role in Cancer prevention
• Not only the diet but even the style of preparing it matters! Replace frying and grilling with other alternative methods of cooking like baking, boiling or steaming. It is also a good idea to introduce healthy spices like garlic, ginger and curry powder for added flavour & taste.
• Schedule regular appointments with your dentist regularly (minimum once every six months) and ask for an oral cancer screening 
• Do a self-exam at home once a month. This will only take a few minutes of your time, but is an extremely important step in preventing Oral Cancer. Use a mouth mirror for those hard-to-see areas. Ensure you check the back and sides of the tongue. Look out for anything suspicious like lumps, bumps, tender areas, white, red or grey patches. In case you encounter any of these, see your dentist at the earliest for a detailed investigation.

Diagnosis of Oral Cancer
In a country like India, where there is such a high prevalence of Oral Cancer, it becomes increasingly important to detect the disease early to reduce the mortality rate of patients suffering from oral cancer. The belief is that if there is a lesion which is detected & treated at a premalignant stage, then the probability of the lesion developing into a cancer is very low
There is naturally a great amount of demand for oral cancer diagnostic techniques that are non-invasive in nature, give results fast and are easy-to-use. In the diagnosis of oral cancer, the lesions in the mouth are first observed by a physician. In the case of suspected malignancy, it is further referred to an oral or maxillofacial surgeon who conducts the relevant clinical exams. In the case of oral cancer, the role of a dentist becomes vital as he has a pivotal role in the early examination of occurrence
Some of the most commonly techniques used for detection of oral cancer include

• Physical Examination including Self examination
• Vital Staining techniques
• Histopathological examination
• Biopsy 
• Imaging Techniques like MRI, CT, PET Scan & X-Ray
• Biomarker detection and biosensors – 

Future Outlook
India is unfortunately but rightfully considered as the world capital for oral cancer cases as it shares one-third of the global burden. The southern parts of the country present the highest incidence rate of oral cancer amongst women – not only in India but globally as well. The genetic and epigenetic are the two major aspects that greatly impact the occurrence of oral cancer. A significant portion (more than 60%) of oral cancer detections in India happen in the advanced stages in comparison to only 40% in developed countries. This single factor contributes to a greatly increased mortality rate in India. As mentioned earlier, the financial burden of the treatment towards Oral Cancer is very high and most of the patients are forced to leave the treatment midway, which further adds to the mortality rate. The treatment of oral cancer majorly depends on the location and size of the tumour, along with the feasibility of organ preservation in the patient. Radiotherapy and surgery are two of the most recommended approaches which are adopted in the earlier stages of oral cancer.
Taking steps for prevention, early detection and timely treatment are critical aspects to tackle the growing oral cancer-related burden in India. The awareness needs to be spread among the population about the causes and consequences of oral cancer; the importance of quitting tobacco, alcohol, and maintaining oral hygiene. It is important that the population are aware of the serious implications for driving them to take some of the preventive measures including giving up / not being addicted to tobacco
Comprehending the importance, numerous research & awareness groups are working on techniques that could aid in early diagnosis of oral cancer. There are multiple Government driven initiatives that aim to drive awareness about the magnitude of the problem of Oral Cancer and the simple yet critical preventive measures to avoid it. There are also several help groups whose key purpose is to educate people about the harmful effects of tobacco and enable them to leave this habit.
Apart from physical examination, the other recommended techniques are Diagnostic Imaging modalities like X-Rays, CT Scan, PET Scan, MRI and Endoscopy. Histopathological examination, vital staining techniques, biopsies such as brush biopsy, biomarker detection with biosensors or immunohistochemistry, radiology, and optical imaging systems are some of the most frequently employed measures for diagnosis of oral cancer in India. Medical and technological research institutes in India have been working together to develop and deliver innovative technologies to fulfil the requirement of a growing and diverse population. 
The conventional diagnostic methods are often expensive, take a lot of time, is dependent on expert technicians which itself is a short supply in our country, and sometimes require surgical intervention. The newer biosensor-based oral cancer biomarker sensing techniques are perceived to possess great potential to be incorporated in meaningful diagnostic practices. 
Although numerous studies have been published, India presently is yet to have a sustainable solution for non-invasive, easy-to-use, fast & cost-effective techniques that are not dependent on a high amount of human expertise to process, evaluate and interpret the test results. Emerging advanced commercialized techniques need government support and encouragement by professionals for integration in clinical diagnostic practices.

References:

https://www.jpsr.pharmainfo.in/Documents/Volumes/vol7Issue10/jpsr07101509.pdf
http://ijbc.ir/article-1-14-en.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515567/
https://main.mohfw.gov.in/sites/default/files/Cancer%20Prevention%20And%20Control%20In%20India.pdf