The incidence of mouth cancers among Iraqi people is reviewed from 1973-2021 in different Iraqi provinces. The incidence rates are also illustrated in relation to age, sex, site of cancer and year of registration. Incidence rate differs widely in relation to locality, age, sex and race. The risk factors for the incidence can be attributed to tobacco and/or alcohol consumption. The relationship between diet and nutrition to the risk of cancer development has been established by several epidemiological and laboratory studies. They indicated that low intake of fruits and vegetables predisposes to increased risk of cancer development. Other risk factors include genetic, sun exposure, mate drinking (tea-like beverage), viral infection, fungal infection and chronic trauma.
Adults and children of both sexes are infected. All authors in Iraq indicated that tongue is the most common site for mouth cancer among Iraqi people. Implementing a national control program should include a primary health care, health education, well-balanced diet, environmental sanitation and health education to stress the important of the hazard of tobacco and alcohol. The knowledge about mouth cancers considerably increased when the subjects received information from their dentists.
Epidemiology, Incidence, Mouth cancer
Mouth cancers are distributed worldwide. They are responsible for millions of morbidity and mortality. Thus, it is a public health problem in many parts of the world. In addition, cancer might be undetectable and unrecorded in many countries. Oral squamous cell carcinoma is the commonest oral malignancy. It is incident in middle-aged and elderly, although it has been recorded in young adults . An estimated 26, 3000 new mouth cancer cases were reported annually over the world which accounts 2.1% of all new cases were recorded . Socio-cultural behaviour for population has an important role in the geographical distribution of the disease . Incidence rate differs widely in relation to locality, age, sex and race. Few studies were carried out in Arab world in relation to the incidence of mouth cancer including Kuwait , United Arab Emirates , Sudan , Saudi Arabia  and Jordan  as well as in Iraq (The present review).
An increase in incidence was noticed in United Kingdom , Netherland and Denmark , India, Pakistan and Bangladesh . In contrast, a decrease in the incidence have reported in USA, Italy, Hong Kong, France, Germany and Australia .
In Iraq, mouth cancer represents 4.5% of all malignant cancers as recorded by Iraq cancer registry , the present review aimed to determine the analysis of Iraqi mouth cancers data according to age, sex, year of registration and cancer site over time.
The incidence rates of mouth cancer are reviewed according to types of patients including age and sex in different Iraqi provinces (Table 1). The incidence is varying from one region to another.
Table 1: Distribution of mouth cancer in relation to province, years of registration, age and gender. View Table 1
Fuoad, et al.,  result has indicated a slight increase in the rate of mouth cancer over time (14.5%) compared to a five-year (2004-2009) retrospective study (12.3%) in Sulaimania  and another previous study in Baghdad during 1991-2000 (9.97%)  as well as in the present review (Table 1 and Table 2). This can be associated to pollution, recurrent explosions and wars in Iraq. Furthermore, it might be related to the practices of tobacco smoking and drinking alcohol in both men and women which increased the risk of lip cancer worldwide , including Iraq [15,18-20]. All authors in Iraq indicated that tongue is the most common site for mouth cancer among Iraqi people (Table 2) which is in agreement with studies in Europe and USA . Buccal mucosa is the most common site in Mosul , Basrah  as well as among Asian populations due to betel quid/tobacco chewing habits . Cheek was the dominant site in women, while lip, face and mouth floor were observed among men. Lip, tongue, gum, palate found among males than females [18-20,22,23].
Table 2: Incidence of mouth cancers and their types in the Iraqi provinces. View Table 2
Mouth cancer affected males more than females (Table 1). This is in agreement with most similar studies in countries around the world where the ratio is 1.5:1 . The incidence can be explained by the contributions of smoking, alcohol or hormonal factors as well as exposure to radiation due to men’s job which lead to incidence of lip cancer . More than 80% or mouth cancers can be attributed to tobacco and/or alcohol consumption . The relationship between diet and nutrition to the risk of cancer development has been established by several epidemiological studies . They indicated that low intake of fruits and vegetables predisposes to increased risk of cancer development. Certain food as processed meats, cakes, desserts, butter, eggs, soups, red meat, salted meat, cheese, pasta or rice and corn bread . More frequent consumption of fruit and vegetables, particularly of carrots, fresh tomatoes and green peppers were associated with reduced risk of oral and pharyngeal cancer  as well as other food as fish, vegetable oil, bread, cereals, protein, fat, fresh meat, chicken, liver, shrimp and fiber . Other risk factors include genetic , sun exposure , mate drinking (tea-like beverage) , viral infection , fungal infection  and chronic trauma .
Mouth cancer is incident among all types of communities and population samples from both urban and rural regions of Iraq. Adults and children of both sexes are infected. It is an important disease and remain challenge to the dentist and since the early diagnosis of oral cancer is vital in the treatment and prognosis of mouth cancer. Dentist should continue to be encouraged to perform mouth cancer examination for all patients.
Therefore, due to lack of effective chemotherapy or vaccine against cancer, an urgent and efficient preventive and control measures is essential. Implementing a national control program should include a primary health care, health education, well-balanced diet, environmental sanitation and health education to stress the important of the hazard of tobacco and alcohol. Well trained health workers chosen from the same community are valuable in the diagnosis and treatment especially in rural areas and far villages in the country. The knowledge about mouth cancers considerably increased when the subjects received information from their dentists.
Ethics committee approval was not requested for this study.
Authors were involved in collecting data, analysis and righting up.