Published online Apr 14, 2017. doi: 10.3748/wjg.v23.i14.2575
Peer-review started: December 11, 2016
First decision: December 29, 2016
Revised: January 26, 2017
Accepted: February 16, 2017
Article in press: February 16, 2017
Published online: April 14, 2017
Processing time: 125 Days and 21 Hours
To explore the effects of omeprazole on chemoradiotherapy efficacy and tumor recurrence in rectal cancer.
The medical data of 125 rectal cancer patients who received the same neoadjuvant chemoradiotherapy (CRT) followed by surgery were retrospectively collected. Patients who received omeprazole (OME) orally at a dose of 20 mg at least once daily for six days and/or intravenously at 40 mg a day were recognized as eligible OME users (EOU). Otherwise, patients were regarded as non-eligible OME users (non-EOU). Moreover, a preferred OME dose cut-off of 200 mg on tumor recurrence was obtained by receiver operating characteristic (ROC) curves. Patients were divided into two groups: the effective OME group (EOG, OME ≥ 200 mg) and the non-effective OME group (non-EOG, OME < 200 mg).
The good response rate of CRT efficacy (50.8%) in EOU was significantly increased compared with non-EOU (30.6%) (P = 0.02). The recurrence rate in the EOG was 10.3%, which was significantly lower compared with 31.3% in non-EOG (P = 0.025). The good response rate of CRT efficacy in EOG was 55.2%, which was obviously higher compared with 36.5% in non-EOG, with a significant difference (P = 0.072). Multivariate Cox analysis demonstrated that OME (non-EOG and EOG) was an independent and significant impact factor for DFS (P = 0.048, HR = 0.30, 95%CI: 0.09-0.99).
When applied as an adjuvant drug in cancer treatment for relieving common side effects of chemotherapy, omeprazole has a synergetic effect in improving CRT efficacy and decreasing rectal cancer recurrence.
Core tip: In in vitro and in vivo studies, proton pump inhibitors (PPIs) induce apoptosis of gastric cancer cells, B-cell tumors and hepatoblastoma cells and promote autophagy in melanoma cells and pancreatic cancer cells. PPIs also sensitize chemo-resistant tumors to cytotoxic drugs and improve the efficacy of T-cell-based cancer immunotherapy. However, whether PPIs affect chemoradiotherapy (CRT) efficacy, decrease tumor recurrence and improve survival in rectal cancer patients remains unclear. In the present study, when used as adjuvant drug in cancer treatment, omeprazole has a synergetic effect in improving CRT efficacy and decreasing recurrences in rectal cancer.