Recently, we reported on troubling research that found a link between proton pump inhibitor drugs, the world’s most popular medications for heartburn, and gastrointestinal cancer. In a wide-ranging study of nearly 63,500 patients, a group of physicians from the University of Hong Kong concluded that, for those patients who received a proton pump inhibitor as part of treatment for the H. pylori infection, the risk of developing gastric cancer increased by over 200%.
Proton Pump Inhibitors Decrease Efficacy Of Leading GI Cancer Treatment, Study Finds
Now, a new study out of the University of Alberta in Canada has added to concerns over the safety of proton pump inhibitors. Last year, a group of researchers at the University found in a retrospective study of 545 colorectal patients that patients who took a proton pump inhibitor fared worse in their treatment than patients who avoided the medications.
Researchers believe that PPI drugs, by inhibiting the release of stomach acid, could make it harder for the body to absorb capecitabine, one of the leading chemotherapy drugs used to tackle gastrointestinal cancers.
A similar mechanism of action has been proposed to explain the link between proton pump inhibitors, osteoporosis and an increased risk for bone fracture; the drugs may inhibit the absorption of calcium in the gut, leading to weaker bones that break more easily.
PPI Drugs May Inhibit Absorption Of Chemotherapy Drug
In their earlier research, the team from the University of Alberta observed that, among PPI patients, gastrointestinal cancers tended to progress at a quicker rate, resulting in lower survival rates. To add to their understanding of the issue, the group focused in their new study on comparing recurrence-free survival rates between two groups of patients: those who were taking XELOX, a combination of capecitabine and another chemo agent, oxaliplatin, and those being treated with FOLFOX, a cocktail of three chemo drugs, including oxaliplatin, that does not contain capecitabine.
From a group of 389 patients, the researchers found that 23.4% of patients receiving XELOX were also using PPI drugs during their course of treatment. A higher proportion, 28%, of FOLFOX patients were taking proton pump inhibitors. Each of the 389 patients had been diagnosed with a stage 2 or stage 3 colorectal cancer; all of the patients had undergone tumor-removal surgery at a treatment center in Alberta.
Higher Risk Of Death In PPI Patients
Their results are alarming. In patients who received XELOX while taking a PPI drug, recurrence-free survival rates were significantly lower than for patients in the FOLFOX group. “In the XELOX treatment group,” Clinical Oncology News writes, “the percentage of patients free of recurrence or still alive at three years after treatment was 69.5% compared with 82.6% for patients not also taking PPIs.” In other words, the introduction of a PPI appeared to decrease life expectancy substantially.
Another analysis of the data revealed that taking a PPI drug doubled the risk of a cancer recurrence or death. The same relationship was not observed in the group of patients receiving the FOLFOX treatment regimen, a finding that “implicates capecitabine as the determining factor,” Clinical Oncology News reports.
These results are particularly troubling because XELOX, not FOLFOX, appears to be the more effective drug combination. In patients who were not taking a PPI drug, patients who received XELOX had fewer cancer recurrences than patients who were administered FOLFOX.
“PPI Use In XELOX-Treated Patients Should Be Avoided”
Speaking to Clinical Oncology News, the study’s lead author, Grace Wong, said, “our results suggest that PPIs negatively impacted recurrence-free survival in early-stage XELOX-treated patients, and yielding no significant effect among FOLFOX-treated patients. The clinical implication is that PPI use in XELOX-treated patients should be avoided to maximize chemotherapy efficacy.”
Taken in total, recent research on PPI drugs suggests that, not only can these medications increase the risk for gastrointestinal cancer, but they may also make the cancers harder to treat.