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.