**3. Incidence and mortality**

The clinical conditions such as nodular lesions, painless small ulcers, or growths present in very early preclinical invasive early stage cancers culminate the disease. Changes can be easily seen and are clinically detectable through careful visual inspection, and palpation of the oral mucosa was the hallmark of processes. Highlighting the disease prognosis that localized early head and neck cancers ˂4 cm that has not spread to the regional lymph nodes can be successfully treated with either radiotherapy or surgery resulting in 80% of 5-year survival rates [9]. Leukoplakia may be clinically categorized as homogeneous or nonhomogeneous condition, in which a white snowy plaque or patch will form on the tongue. If the lesions have a thin, flat, uniform, smooth, and white appearance, it is categorized as homogeneous, and nonhomogeneous lesions may have a white and red appearance or tiny, white, pinhead-size raised nodules on a reddish background or a proliferative, warty presence. Erythroplakia exists as a red patch with a smooth or granular surface that cannot be categorized clinically or pathologically as any other definable disease [10]. Erythroplakia has a higher chance than leukoplakia

**Figure 1.** Head and Neck Cancer Regions.

2 Prevention, Detection and Management of Oral Cancer

to anchorage occult invasive cancer and to undergo malignant transformation.

Interweaving white lines (known as *Wickham's striae*) with a reddish border or as a mix of reddish and ulcerated areas will appear on oral lichen planus. OSMF, mostly restricted to the people of Indian subcontinent origin and in certain Pacific islands such as the Mariana Islands, presents with a blanching of the oral mucosa, burning sensation, and intolerance to spicy food. As the disease progresses, hardening and weaken of the oral and pharyngeal mucosa occur, leading to reduced mouth opening and difficulty in swallowing and speaking. Smokers who smoke with the lighted end of the tobacco product inside the mouth, known as WHO conveyed that head and neck cancer occurrence and death are high in India, Papua New Guinea, and Taiwan, China, where the habit of chewing betel quid's with tobacco or without tobacco or areca nut chewing is common, as well as in France, Eastern Europe, and parts of South America such as Brazil and Uruguay, where tobacco smoking and alcohol ingestion are high. The age-standardized incidence rates for men are, on average, twice as high as those for women. WHO reported that in selected countries where some reliable cancer registries exist, India is highest and Belarus is lowest, with incidence rates changing by more than five times in men and women. The estimated age-standardized incidence rates of head and neck cancer also fluctuate among countries in different regions [6].

In South and Southeast Asia, buccal (cheek) mucosa is the most common site for head and neck cancer; the tongue is the most prominent site in all other regions [12]. Regional differences in frequency and the site of occurrence are related to the major causes, which are betel quid and tobacco chewing in South and Southeast Asia and alcohol and smoking in Western countries [13]. The mortality rates of head and neck cancer range between 1 and 15 per 100,000 persons in different regions; mortality rates exceed 10 per 100,000 in Eastern European countries, such as the Czech Republic, Hungary, and the Slovak Republic. Head and neck cancer mortality rates are influenced by head and neck cancer incidence, access to treatment, and deviations in site distribution.

The trends in incidence and mortality among men and women are closely correlated with the patterns and trends in tobacco and alcohol use. Increase in tobacco and areca nut chewing and alcohol consumption causes an elevated incidence rate which has been reported in Karachi [14] and in Taiwan [15]. Head and neck cancer incidence and mortality rates have been gradually falling over the past 2 decades because of declining smoking prevalence and alcohol ingestion in the US [16]. However, because of human papillomavirus (HPV), there is an increase in cancers at the base of the tongue, which has been observed in white men in the United States [17].

It was reported that over the past 2 decades, incidence and mortality rates for head and neck cancer have been declining steadily in most European countries. The increasing rates had been observed in some Central European countries, such as Hungary and the Slovak Republic, reflecting changes in alcohol and tobacco consumption [18]. There was a steady decrease in the mortality rate of head and neck cancer in France since reaching a peak in the early 1990s and the decline correlated with the reduction in alcohol consumption. Incidence and mortality have been stable in the Nordic countries, the Russian Federation, and the United Kingdom. Mortality rates have been steadily declining in Australia and Hong Kong SAR, China but increasing in Japan and the Republic of Korea [19].

the associated cancer burden has declined as a result [22]; currently, 1.5 and 2% of all cancer deaths in HICs and LMICs, respectively, are attributed to high salt intake, compared with 2.2 and 2.7%, respectively, in 1990 is highlighted by Lim and others. In the United Kingdom, 10% of new stomach cancer cases diagnosed in 2010 may be attributable to high salt intake [23].

Introductory Chapter: Head and Neck Cancer http://dx.doi.org/10.5772/intechopen.86272 5

Over the past era, key factor in the decline in cancer incidence reported to be the better food preservation methods and reducing the salt. The levels of red meat consumption in recent decades may explain the low colorectal cancer rates in southern Asia [21], as well as the high rates in many Western European countries were reported [24, 25]. Researchers find association for obesity and overweight to cancer is firmer than the dietary evidence has been reported, indicating that 3 and 6% of cancer deaths in LMICs and HICs, respectively, can be attributed to excess weight, as quantified by the body mass index (BMI) [26, 27]. High BMI was raised as a cause of cancer deaths more substantively in LMICs, a 54% increase over the past 30 years,

A buccal mucosa carcinoma is a violent form of head and neck cancer associated with the high rate of locoregional reappearance and poor existence [29]. It is the most common cancer in men and the third most common cancer in women in India [30]. National Cancer Registry Program (India) has stated approximately 13,500 cases of buccal mucosa carcinoma from various Indian cancer registries [31]. Indian Council of Medical Research guideline on buccal mucosa carcinoma management reported that there is the absence of national and international data specifically on buccal mucosa cancer, and very few randomized studies from India on various aspects of buccal mucosa cancer are available [32]. Tumor thickness and other prognostic factors were institutes to be not correct predictors of relapse and most of the studies were not adequately powered to draw a definite conclusion. Patients with head and neck cancer observed by computed tomography, magnetic resonance imaging (MRI), ultrasound-guided fine needle aspiration biopsy, and positron emission tomography (PET) have significant false positive and false negative results, invariably not capable of detecting nodal metastasis [33, 34]. Genetic alterations recognized to date have not been used clinically in the assessment of surgical margins, and no study has developed a gene signature that can accurately predict which patients with buccal cancer are at a higher risk of disease recurrence. Traditional surgical procedures may miss involved lymph nodes due to a limitation in histopathology examinations [35]. Lymph-node metastasis can be predicted by gene expression profiles of primary oral cavity squamous cell carcinomas [36]. Further, markers of prognosis will be validated by qRT-PCR technique. Gene expression profiles of primary tumor and their matched normal mucosa and comparing with different tumor stage and lymph-node status and to identify clinically significant prognostic markers

Increase in the incidence of buccal mucosa carcinoma was observed from the hospital registry over the last 15 years [3]. The incidence and cumulative risk of buccal mucosa cancer in

**Figure 2** describes the mechanism of salivary involvement with diet and cancer.

compared with a 26% increase in HICs over the same period [28].

**5. Buccal mucosa cancer—our perspective**

is warranted.

## **4. Diet and head and neck cancer**

The current report highlighted that about 15% of all cancer deaths are related to unhealthy diets, including high intake of red meat, processed meat, and sodium, as well as low intake of fruits and vegetables [20]. Most research is still not consistent about specific nutritional items yet for the cause of cancer geographically [21]. The most current comprehensive review of diet and cancer risks confirms an elevated risk related to red and processed meat but finds less evidence supporting the benefit of the consumption of fruits and vegetables in reducing risk [22]. When well-established risk factors are included in the estimation of cancer, the variations in the strength of the evidence in different studies over time makes the measurement of dietary intake problematic in epidemiological studies. Nearly 5% of cancer deaths worldwide (387,000) would be attributable to dietary risk factors [20]. Ingestion of red meat and processed meat increases the risk of colorectal cancer by an estimate of 43% [21]. Ingestion of red meat and processed meat is generally rising in low- and middle-income countries (LMICs), but is stable in high-income countries (HICs). Another major dietary risk factor is high salt intake, which increases the risk of stomach cancer. Globally, salt intake has declined, and

**Figure 2.** The mechanism of salivary involvement with diet and cancer.

the associated cancer burden has declined as a result [22]; currently, 1.5 and 2% of all cancer deaths in HICs and LMICs, respectively, are attributed to high salt intake, compared with 2.2 and 2.7%, respectively, in 1990 is highlighted by Lim and others. In the United Kingdom, 10% of new stomach cancer cases diagnosed in 2010 may be attributable to high salt intake [23].

**Figure 2** describes the mechanism of salivary involvement with diet and cancer.

Over the past era, key factor in the decline in cancer incidence reported to be the better food preservation methods and reducing the salt. The levels of red meat consumption in recent decades may explain the low colorectal cancer rates in southern Asia [21], as well as the high rates in many Western European countries were reported [24, 25]. Researchers find association for obesity and overweight to cancer is firmer than the dietary evidence has been reported, indicating that 3 and 6% of cancer deaths in LMICs and HICs, respectively, can be attributed to excess weight, as quantified by the body mass index (BMI) [26, 27]. High BMI was raised as a cause of cancer deaths more substantively in LMICs, a 54% increase over the past 30 years, compared with a 26% increase in HICs over the same period [28].
