When used correctly, a class of heartburn drugs called proton pump inhibitors can prevent esophageal cancer. Used incorrectly, they may increase the risk of gastric cancer. An article in Science News warned that up to 69 percent of these drugs may be prescribed with no medical reason, so we need to pay more attention to the risks and benefits.
Proton pump inhibitors are the most powerful option for reducing stomach acid. They block the production of acid at the cellular level. Well known brands are Prilosec, Nexium, and Aciphex. Valid indications for these drugs include:
2. Gastroesophageal reflux disease (GERD)
3. Erosive esophagitis
4. Frequent heartburn caused by excess stomach acid
However, Reference 1 reported that proton pump inhibitors may also be viewed as lifestyle drugs, used to prevent heartburn from partying, or prescribed for patients who simply expect a prescription.
Several studies have linked proton pump inhibitors to higher rates of gastric cancer. The reduction in acid production leads to increased secretion of gastrin, and too much gastrin is associated with the development of gastric cancer. However, it is difficult to separate the effects of the drugs from the risk of the patient's original condition. Many patients on these drugs have been infected with Helicobacter pylori, and are at increased risk for gastric cancer on that basis.
The authors of Reference 2 compared gastric cancer rates in people taking two different classes of heartburn drugs: proton pump inhibitors and histamine-2-antagonists. Zantac and Tagamet are examples of histamine-2-antagonists, and are less potent at reducing stomach acid. By comparing the effects of these two different drug classes, researchers hoped to separate the risks of proton pump inhibitors from the risks of the disease they were treating.
The results indicated a higher risk of gastric cancer for patients on proton pump inhibitors. However, the numbers were too small for definitive conclusions. The authors noted that the proton pump inhibitor group may have contained patients with more severe disease to start with.