Luis Bujanda
Digestive specialist and Professor of Medicine at the University of the Basque Country (UPV/EHU)
In general, the article does not say anything new. It provides a general analysis of the incidence of gastric cancer worldwide among men and women and by age, and states that it is the fifth most common cancer. These data are already well known.
The incidence of gastric cancer has two very important conditions. One is Helicobacter pylori. As the article states, three-quarters of gastric cancers are directly related to Helicobacter pylori, although the figure is probably higher, and this is already known.
The other important factor is all dietary conditions and genetic predisposition.
Therefore, Helicobacter pylori plays a fundamental role and runs parallel to the prevalence of the infection worldwide, such that underdeveloped countries have, on the one hand, poorer hygiene and sanitation conditions and higher prevalence rates of Helicobacter pylori, above 50-60%. In contrast, in Western countries such as Spain and others, the prevalence of Helicobacter pylori has fallen dramatically and is now below 35%.
Is prevention necessary? It will depend on the geographical area, fundamentally, and also on the prevalence of Helicobacter pylori infection and the incidence of gastric cancer in different regions. Therefore, it is not possible to give general advice on gastric cancer.
In Spain, the number of cases of gastric cancer has been steadily declining, as have the rates of infection with Helicobacter pylori. In Spain, it ranks eleventh in terms of incidence, so strategies to screen for and treat Helicobacter pylori are probably not cost-effective here. They may be in other countries or with other prevention campaigns, such as those carried out in Japan, with screening through gastroscopy or other techniques.
Therefore, the article as a whole adds little to what is already known and I believe it falls short of expectations regarding Helicobacter pylori or the prevention of gastric cancer. An important role has been played by the vaccine against Helicobacter pylori, which has been discussed for decades but, to date, there is nothing effective to eradicate or prevent this infection. The other treatments have advantages and disadvantages in terms of techniques and diagnostics applicable to the general population, acceptance, and the effects that eradication treatments may have.
As for the incidence of gastric cancer in young people, it is relatively low, probably less than 6%, which is very alarming, but in real terms it is being taken out of context and each cancer should be analysed individually.