Can antibiotics and proton pump inhibitors alter the effectiveness of treatment for patients with non-small cell lung cancer?

This study examined the effects of antibiotics or proton pump inhibitor (PPI) drugs on treatment for patients with non-small cell lung cancer (NSCLC). The authors found that both antibiotics and PPIs reduced the effectiveness of biological therapy but not chemotherapy.

Not all patients with NSCLC respond to chemotherapy, such as docetaxel (Taxotere), or biological therapy, such as atezolizumab (Tecentriq). Some evidence suggests that other drugs interact with and reduce the effectiveness of chemotherapy/biological therapy. These include antibiotics, to treat infections, and proton pump inhibitors (PPIs), to treat acid in the gut. It is unclear if patients who take antibiotics or PPIs during treatment for NSCLC have poorer treatment results.

1512 patients with NSCLC were divided into two groups. The first group (757 patients) were given atezolizumab. The second group (755 patients) were given docetaxel. In the first group, 169 patients also received antibiotics, 234 patients received PPIs and 74 received both antibiotics and PPIs during treatment. In the second group, 202 patients received antibiotics, 260 patients received PPIs and 82 patients received both antibiotics and PPIs during treatment. Patients were followed for an average of 19.2 months.

Overall, patients’ chances of survival were reduced by 20% with antibiotics and 26% with PPIs. In the atezolizumab group, the chance of survival was reduced by 32% by antibiotics. Patients who did not take antibiotics survived for 14.1 months compared to 8.5 months in patients who did. PPIs reduced the chance of survival by 45%, from 14.5 months to 9.6 months. In the docetaxel group, no differences were seen between patients who received antibiotics or PPIs and those that did not.

PPIs reduced the time before the cancer worsened. Overall, patients who took PPIs had a 14% reduced chance of survival without cancer worsening. In the atezolizumab group, this was a 30% reduced chance. On average, patients who did not take PPIs survived for 2.8 months without cancer worsening compared to 1.9 months in patients who received PPIs. Antibiotics did not alter patients’ survival without cancer worsening. In the docetaxel group, neither antibiotics nor PPIs altered patients’ survival without cancer worsening.

The authors concluded that antibiotics and PPIs reduce the effectiveness of atezolizumab treatment for patients with NSCLC.

The manufacturer of atezolizumab, Genetech, funded this research. This study was limited by its use of medical records data of a trial not focused on antibiotic or PPI use in patients. This also meant that there were small numbers of patients who were taking antibiotics and/or PPIs.  Therefore, the results should be validated in a larger, more focused study.