High-doses of proton pump inhibitors in refractory gastro-intestinal cancer: A case series and the state of art

Background In recent years, proton pump inhibitors (PPIs) have been investigated at high-dose to modulate tumour microenvironment acidification thus restoring chemotherapeutic sensitivity. Moreover, several clinical data supports the role of cytotoxic drugs at low-dose continuously delivered as anticancer therapy. Methods Clinical records of three patients affected with gastrointestinal cancer refractory to standard treatments, who had received a combination of high-dose rabeprazole and metronomic chemotherapy were reviewed. Results The first case, a 78-year-old man was treated for lung metastasis from colon adenocarcinoma. The second case, a 73-year-old man was treated for metastatic rectal cancer to the liver. The third one, a 68-year-old man, underwent the combination regimen for colon cancer with lung, liver and peritoneal metastases. Conclusions Despite the failure of previous standard chemotherapy for metastatic disease, good clinical outcome was shown in these patients treated with an unconventional association of high-dose PPIs and metronomic chemotherapy.