Esophageal Cancer Deaths Research Articles

Familial Aggregation of Oesophageal Cancer in Yangcheng County, Shanxi Province, China

Oesophageal cancer is the second most common cause of cancer death in China and is particularly prevalent in northern China. Genetic factors have been studied less than environmental factors in the aetiology of this disease. This study was conducted to evaluate familial aggregation of oesophageal cancer. All households in Yangcheng County were interviewed in 1979 to determine family history of oesophageal cancer. In 1989, vital status for all family members from three Yangcheng villages was determined and re-interviews were conducted among families who reported a positive family history of oesophageal cancer in 1979. Risk of oesophageal cancer was evaluated by comparing family and individual rates of oesophageal cancer during the 1979-1989 interval stratified by the number of family members with oesophageal cancer prior to 1979. More families with prior oesophageal cancer history reported new oesophageal cancer deaths during the follow-up period than families without prior history (19% versus 5%). Oesophageal cancer rates increased with increasing positivity of family history, and adjustment for other risk factors did not substantially alter this result. We conclude that these data provide evidence for familial aggregation of oesophageal cancer.

Post-marketing Drug Surveillance—How Far Have We Got?

The early recognition of serious adverse effects of drugs is clearly important for ensuring optimum health care. Since only about 3000 patients will receive a new drug prior to licensing, it is essential that systems exist to monitor their safety thereafter. Within the United Kingdom, the corner-stone of this post-marketing surveillance has been the yellow card system of reporting adverse drug reactions to the Committee on Safety of Medicines. Now over 25 years old, this mechanism is generally highly successful, even though underreporting is known to occur. In reviewing the future requirements for adverse drug reaction monitoring (in the aftermath of the Opren affair), the Second report of the Working Party on Adverse Drug Reactions [1] concluded that there was a need for other independent systems to monitor new drugs, although they recognized the difficulty of creating, maintaining and funding such enterprises. Apart from Prescription Event Monitoring [2], no other system has been developed in this country. The ideal resource should not only be able to detect adverse reactions with new drugs but also to examine specific drug toxicity issues that arise. Such an issue, raised initially on the theoretical grounds that a reduction in intragastric acidity increases nitrosamines [3], is whether taking the H2-receptor antagonist, cimetidine, might result in the development of gastric cancer. Initially a sharp reduction in the sales of the drug followed this suggestion but today, 10 years later, H2-receptor antagonists, including cimetidine, are amongst the most commonly prescribed drugs. Actual data on the cancer risk have been difficult to obtain but in this issue, Dr ColinJones and a team of distinguished investigators report the results of an ad hoc postmarketing surveillance study of cimetidine which started in 1978. Their paper deals specifically with the incidence of carcinoma of the stomach and oesophagus in a cohort of 9928 patients for whom cimetidine was prescribed 10 years earlier. They conclude that there is no evidence for a link between cimetidine therapy and the subsequent occurrence of gastric carcinoma. However, they did find a small rise in oesophageal cancer deaths in years 7 and 8. What confidence can we take from this result? The question of statistical power needs to be considered. Adverse drug reactions are more difficult when the supposed toxicity already occurs spontaneously in the population. In 1988, stomach and oesophageal malignancy ranked as the third and seventh most common causes of cancer death. [4].Thus if the expected background incidence of deaths from gastric carcinoma is four deaths per 10 000 persons per year (as quoted), a similar cohort of 35 500 patients would need to be studied [5] to exclude a doubling in the incidence of gastric

Post-cimetidine Surveillance for up to Ten Years: Incidence of Carcinoma of the Stomach and Oesophagus

The long-term effects of cimetidine on the occurrence of gastric and oesophageal cancer were assessed in a prospective cohort study of 9928 patients who had been prescribed cimetidine. They were first identified between 1978 and 1980, and cancer registrations and deaths were identified among them over a period of up to 10 years. One hundred and eleven cancers were identified after the start of cimetidine treatment: 71 were adenocarcinomas of the stomach, 27 were carcinomas of the cardia and/or oesophagus (22 adenocarcinomas, five unknown histology) and the remaining 13 tumours were squamous cell cancers of the oesophagus. Only six patients presented with early gastric cancers. Over a period of eight years the ratio of observed to expected (O/E) gastric cancer deaths has fallen from 10.7 (p < 0.001) to 1.2 (NS). The O/E ratio of oesophageal cancer deaths also fell over the first six years of study, from 5.4 (p < 0.01) to 1.4 (NS) but it has risen slightly in years 7 and 8 to 3.7 (p < 0.05). These findings do not suggest that there is an increased risk of developing oesophageal or gastric cancer from cimetidine treatment, and are generally consistent with cimetidine being used inadvertently to treat the early symptoms of gastric and oesophageal cancer. The slight rise in oesophageal cancer deaths in years 7 and 8 was unexpected and will be the subject of further observation.