Pernicious anemia is a risk factor for stomach cancer. However, data by anatomical subsite are not available.
|Risks increased with increasing follow-up duration.|
In addition, patients with pernicious anemia may have an increased risk of esophageal cancer.
In this study, researchers from Sweden evaluated 21,265 patients who were hospitalized for pernicious anemia between 1965 and 1999. Patients were followed for an average of 7.1 years.
The research team estimated relative risk using a standardized incidence ratio (SIR), which was adjusted for sex, age, and calendar year. Swedish nationwide cancer incidence rates were used as reference.
The team identified excess risks for squamous cell carcinoma of the esophagus (SIR 3.3), and stomach cancer distal to the cardia (SIR 2.4), in pernicious anemia patients. These risks increased with increasing follow-up duration.
Furthermore, the researchers found that, among distal stomach cancers, the greatest risk was for carcinoid tumors (SIR 26.4).
However, when compared to the general population, the team were unable to identify an increased risk of adenocarcinoma of the esophagus (SIR 1.7) or gastric cardia (SIR 1.2).
Drs Ye and Nyrén concluded, "Achlorhydria following type A atrophic gastritis is associated with an elevated risk of adenocarcinoma of the non-cardia stomach, and surprisingly, with a risk of esophageal squamous cell carcinoma".
"In contrast, no significant association, either positive or negative, was found with esophageal or cardia adenocarcinoma".
"The mechanism for the observed increased risk of esophageal squamous cell carcinoma warrants further study".