Is there any relationship between drug addiction and the development of a signet ring cell carcinoma of the stomach?

We present three young patients diagnosed with signet ring cell carcinoma of the stomach. All had in common the smoking rather than the injecting route of administration of drugs, such as heroin. In the smoking route, pieces of nickel scourer are mixed with the drug. This heavy metal has known carcinogenic effects. Chronic exposure of the gastric mucosa to nickel, from oropharynx, could be a risk factor for the development of gastric adenocarcinoma in heroin smoking addicts.