All mouth cancer patients in Myanmar use smokeless tobacco, study finds

A study in Myanmar has found that all mouth cancer patients use smokeless tobacco, researchers report at the ESMO Asia 2017 Congress. Betel quid chewing often starts in adolescence and is associated with smoking and drinking alcohol, which are also risk factors for oral cancer.

According to GLOBOCAN 2012, more than half of oral cancers in the world occur in Asia where an estimated 168,850 new cases were diagnosed in 2012. Of these, approximately 11% of patients were from Southeast Asia.

Lead author Dr Khin Khin Nwe, medical oncologist, Toungoo General Hospital, Toungoo, Myanmar said: "According to previous studies the incidence of oral cancer, also called mouth cancer, in Southeast Asia has been disturbingly high for many years. It has also been shown that smokeless tobacco use is common in this region - for example in Myanmar more than 50% of men use betel quid."

This observational study investigated the lifestyle behaviors of head and neck cancer patients that may have contributed to their disease. The cross-sectional study was conducted in the medical oncology unit of Toungoo General Hospital in 2016. All head and neck squamous cell cancer (HNSCC) patients who came to the hospital were included in the study. Participants were asked about betel quid chewing, smoking, and alcohol.

Of the 307 cancer patients who visited Toungoo Hospital that year, 67 (22%) had HNSCC and were included in the study. Out of the 67 patients, 41 were male and 26 were female. The mean age was 59.2 years (range 36 to 81) for men and 58.7 years (range 19 to 86) for women. The most common cancer site was oral cavity (34.3%), followed by larynx (25.4%), oropharynx (11.9%), nasopharynx (11.9%), hypopharynx (10.4%), lip (4.5%), and nose (1.5%).

Regarding lifestyle habits of the entire study population, 20 patients (30%) chewed betel only; 19 patients (28%) chewed betel and smoked tobacco; 19 patients (28%) chewed betel, smoked tobacco, and consumed alcohol. Two patients smoked tobacco and drank alcohol, two smoked tobacco only, two had none of the risk factors, and information was unavailable for three patients.

All oral cavity (mouth) cancer patients were betel quid chewers. In addition, 48% smoked tobacco and 44% consumed alcohol. The majority (87%) of mouth cancer patients said they kept betel quid in the buccal cavity (cheek) most of the time.

Nwe said: "We found that all patients with mouth cancer chewed betel quid. Most had started the habit as teenagers and had found it too difficult to quit. Betel quid chewing appeared to interact with tobacco smoking and alcohol drinking in an additive way in this population."

Nwe concluded: "Chewing of betel quid has been common in Southeast Asia, including Myanmar, for a long time and our study shows that it is a public health problem. Efforts are needed to increase awareness of the risks of betel quid chewing so that adolescents do not start the habit and adults are encouraged to quit. This may help to prevent head and neck cancer."

Commenting on the topic, Dr Makoto Tahara, Chief, Department of Head and Neck Medical Oncology, National Cancer Centre Hospital East, Chiba, Japan, said: "Given the number of health issues associated with chewing betel quid, particularly oral cancer and precancerous conditions such as leukoplakia and oral submucous fibrosis, understanding ways to reduce betel quid chewing is of global public health importance. In the last decade, betel quid has been classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC)."

"Limited research has been conducted to understand the behavioral and psychosocial factors that lead individuals to initiate and/or maintain betel quid chewing," he continued. "Determining such psychosocial and behavioral risk factors would help design prevention and treatment programmes aiming to reduce the prevalence of betel quid chewing. In many countries within the Western Pacific region, the long-established behavior of betel quid use is integral to community life, from routine aspects of daily life to ceremonial celebrations. Given the social importance of chewing betel quid, chewers might fear the negative social repercussions associated with quitting. For instance, for an individual attending a social or cultural event where betel quid is offered, refusing it could be construed as an insult by the host."

Tahara said: "Interventions designed to treat or prevent betel quid chewing may need to include a strong social/cultural component. For example, such interventions may provide chewers trying to quit with skills regarding how to deal with the social/cultural pressures to chew. With regards to prevention, if social influence is found to play an important role in chewing initiation among youths and young adults, perhaps social influence-based smoking cessation interventions that have been found to be effective in this age group may be adapted to prevent betel quid initiation."