Oesophageal and gastric carcinoma in the Republic of Yemen

Abstract

(Mahboubi et al., 1973), whereas the probable incidence in the Yemen, from the experience of neighbouring countries (Parkin, 1986;Muir et al., 1987;Cook-Mozaffari, 1989), is only moderate by world standards. Comparison of the gastroendoscopic data from Sana'a with that from other centres in the country suggests that the rates may be locally elevated in Sana'a, perhaps because of the unusually high number of female patients.In western populations, where the disease is generally rare but affects men more than women, smoking and alcohol together account for a high proportion of oesophageal cancer risk (Day and Munoz, 1982). In Yemen, as in the highincidence belt of central Asia, cigarette smoking is rare and alcohol consumption is socially unacceptable in the Moslem culture. However, the water-pipe (Mada'a) is widely smoked by both men and women in Yemen, and the leaves of the Qat plant (Catha edulis) are commonly chewed for their mild stimulant properties, attributable to the alkaloid cathinone, which has close structural and pharmacological similarity to amphetamine. Qat contains tannins that thicken the mucosa of the oropharynx and oesophagus (Drake, 1988) and may be carcinogenic (Craddock, 1993). In India, a particularly elevated risk of oesophageal cancer has previously been found for smokers who also chew betel quid without tobacco (Jussawala, 1971).A preliminary survey has been carried out in Sana'a, in which the smoking and Qat-chewing habits, as well as the age/sex and demographic features, of all oesophageal cancer patients diagnosed during 1991 were investigated by questionnaire and were compared with those of gastric cancer patients. Known risk factors are generally dissimilar for the two sites of malignancy, apart from an apparent protective effect of fresh fruit and vegetables that affects both sites (Cook-Mozaffari, 1989;Forman, 1991) and a slight effect of smoking for gastric malignancies that mostly seems to be associated with tumours of the cardia (Rios-Castellanos, 1992). In Sana'a, only 17 male and one female cigarette smoker were found among the total sample of 183 patients, with an even site distribution. Only one patient admitted to drinking alcohol. A higher (but not statistically significant) frequency of Qat chewing and/or water-pipe smoking was found among oesophageal cancer patients for both men and women and for a group (20 men and three women) with tumours at the gastro-oesophageal junction or cardia (Table I).Most Qat chewers were also water-pipe smokers, and numbers were too few to isolate any independent effect of either factor individually. The proportion of chewers and smokers among women was only about half that in men, so that these habits alone could not account for the apparent elevated risk in women seen in Sana'a. No differences were found in the patients' residence and age distribution.A case-control study of oesophageal and gastric cancer is now under way in the Yemen to investigate further these preliminary findings and also to look at other factors which might affect ...

Khat (Catha edulis) consumption causes genotoxic effects in humans

“…Gunaid and co-workers 36 found an indication for an increase in cancer in the cardia and gastroesophageal junction in individuals from Yemen who chewed khat and smoked water pipes, but the number of cases (in total 20) was insufficient to identify independent effects of the 2 factors. In a 2-year follow-up study on head and neck cancer incidence in Saudi Arabia (28 patients), a total of 8 cases of oral cancer were included.…”

Evaluation of the Cytotoxic and Genotoxic Potential of Khat (Catha edulis Forsk) Extracts on Human T Lymphoblastoid Cell Line

“…Two epidemiological studies on different human populations have been performed however, the results of which suggest that khat use may well be associated with an increased risk of cancer of the upper gastrointestinal tract. In the first study a high frequency of khat chewing and water pipe smoking was reported within a group of 3064 men and women with a high frequency of tumour of gastro-oseophageal junction or cardia [15] . The second study, on the other hand, reported an increased incidence of oral cancer among 25 long term khat users who were non-smokers residing in the Asir area of Saudi Arabia [10] .…”

Oral cancer: Breath of death

“…3 Oesophageal and gastric carcinoma have been observed in khat chewers in both men and women in Yemen. 4 There is evidence connecting khat chewing to genetic damage of the oral mucosa and cancer. 5 Mahantayya V. Math, Yashoda R. Kattimani, India…”