Table 1.
Main characteristics of the included studies.
| Author | Principal Institution(s) Involved | Study Design | Study Period | Number of Patients | Patients’ Disease Characteristics | Oral Anti-cancer Drug | Type of GAS |
|---|---|---|---|---|---|---|---|
| Ha, 2014 [23] | Cross Cancer Institute, Department of Oncology, Edmonton, Alberta, Canada | retrospective | 2006–2013 | 383 | mRCC | Sunitinib | PPI |
| Sun, 2016 [27] | Cross Cancer Institute, Department of Oncology, Edmonton, Alberta, Canada | retrospective | 2008–2012 | 298 | Early stage CRC | Capecitabine | PPI |
| Chu, 2015 [19] | Cross Cancer Institute, Department of Oncology, Edmonton, Alberta, Canada | retrospective | 2007–2012 | 507 | EGFR mutant advanced NSCLC | Erlotinib | PPI, H2RA |
| Zenke, 2016 [30] | Department of Thoracic Oncology, National Cancer Center Hospital East, Kashiwa, Japan | retrospective | 2008–2011 | 130 | EGFR mutant advanced NSCLC | Gefitinib Erlotinib |
PPI, H2RA |
| Kumarakulasinghe, 2016 [24] | Department of Haematology-Oncology, National University Cancer Institute, Singapore | retrospective | 2008–2013 | 157 | EGFR mutant advanced NSCLC | Gefitinib Erlotinib |
PPI, H2RA |
| Chen, 2016 [18] | Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan | retrospective | 2010–2013 | 269 | EGFR mutant advanced NSCLC | EGFR TKIs NOS | PPI |
| Graham, 2016 [21] | Department of Oncology, Cancer Centre of Southeastern Ontario, Queen’s University, Kingston | retrospective | 2005–2011 | 117 | CRC | NA | PPI |
| Chu, 2017 [20] | Cross Cancer Institute, Department of Oncology, Edmonton, Alberta, Canada | retrospective analysis (phase III trial) | 2008–2012 | 545 | GEJC | Capecitabine | PPI |
| Zhang, 2017 [31] | Guangdong Medical University Affiliated Longhua Central Hospital, Shenzhen, China | retrospective | 2008–2016 | 125 | CRC | Capecitabine | PPI |
| Lalani, 2017 [16] | Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, USA | pooled analysis (phase II/III studies) | 2003–2013 | 2188 | mRCC | Sunitinib Axitinib Sorafenib |
PPI |
| McAlister, 2018 [25] | Vanderbilt-Ingram Cancer Center, Nashville, USA | retrospective | 2010–2015 | 90 | mRCC | Pazopanib | PPI, H2RA |
| Tvingsholm, 2018 [28] | Danish Cancer Society Research Center, Copenhagen, Denmark (Danish Cancer Registry) | retrospective | 1995–2011 | 353,071 | Solid Tumors (Danish Cancer Registry) | NA | PPI |
| Wong, 2019 [29] | Cross Cancer Institute, Department of Oncology, Edmonton, Alberta, Canada | retrospective | 2004–2013 | 389 | stage II-III CRC | Capecitabine | PPI |
| Fang, 2019 [21] | Chang Gung Memorial Hospital, Chiayi Branch, Puzi City, Chiayi County, Taiwan | retrospective | 1997–2013 | 1278 | EGFR mutant advanced NSCLC | Gefitinib | PPI |
| Mir, 2019 [17] | Gustave Roussy, Sarcoma Group, Villejuif, France | retrospective | 2005–2007 2008–2010 |
333 | STS | Pazopanib | PPI, H2RA |
| Sharma, 2019 [26] | The University of Mississippi, Oxford, Mississippi, USA (SEER Database) | retrospective | 2007–2012 | 12,538 | Solid Tumors (SEER Database) | TKIs | PPI |
Legend: CRC, colorectal cancer; GEJC, gastro-esophageal junction cancer; EGFR, epidermal growth factor receptor; GAS, gastric acid suppressants; H2RA, histamine-2 receptor antagonists; NA, not applicable; NOS, not otherwise specified; NSCLC, non-small cell lung cancer; PPI, proton-pump inhibitors; mRCC, metastatic renal cell carcinoma; SEER, Surveillance, Epidemiology, and End Results; STS, soft-tissue sarcoma; TKI, tyrosine kinase inhibitors; USA, United States of America.