Table 1.
Characteristics of included studies
| Study ID | Country | Study design | Center Multi/single | Sample size | Age Median (range) | Gender Male n (%) | Interventions | Outcomes | Full text/abstractd | |
|---|---|---|---|---|---|---|---|---|---|---|
| Effectiveness | Safety | |||||||||
| Controlled study | ||||||||||
| Arai 2021 [21] | Japan | Retrospective observational study-cohort | Multi |
108 RAM + PTX: 21 Taxane: 87 |
63 (25–83) | 62 (57.4) | RAM + PTX; taxane | – | AEs | Full text |
| Ishikawa 2020 [26] | Japan | Retrospective observational study-cohort | Single |
128 RAM + PTX: 93 RAM + nab-PTX: 35 |
RAM + PTX: 67.2 (30–84) RAM + nab-PTX: 66.6 (34–79) |
89 (70) | RAM + nab-PTX; RAM + PTX | ORR, OS, PFS (RECIST 1.1) | AEs (CTCAE 4.0) | Full text |
| Okunaka 2020a [24]/Okunaka 2020b [23]a | Japan | Retrospective observational study-cohort | Single |
251 RAM + nab-PTX: 113 RAM + PTX: 138 |
nab-PTX + RAM: 67 (25–84) PTX + RAM: 69 (40–85) |
166 (66.1) | RAM + nab-PTX; RAM + PTX | ORR, DCR, OS, PFS (RECIST 1.1) | TRAEs (CTCAE 4.0) | Full text |
| Imazeki 2019 [30] | Japan | Retrospective observational study-cohort | Multi |
154 PTX + RAM: 91 PTX: 63 |
PTX + RAM: 64 PTX: 64 |
110 (71.4) | RAM + PTX; PTX | ORR, DCR, OS, PFS | AEs | Abstract |
| Jung 2018 [34] | Korea | Retrospective observational study-cohort | Multi |
265 RAM: 37 RAM + PTX: 228 |
RAM + PTX: 57 (23–81) RAM: 62 (35–80) |
178 (67.2) | RAM + PTX; RAM | ORR, DCR, OS, PFS (RECIST 1.1) | TRAEs (CTCAE 4.0) | Full text |
| Masuishi 2018 [32] | Japan | Retrospective observational study-cohort | Multi |
305 RAM + PTX: 127 PTX: 178 |
– | – | RAM + PTX; PTX | OS, PFS | AEs | Abstract |
| Shoji 2018 [31] | Japan | Retrospective observational study-cohort | Single |
85 RAM + PTX: 28 PTX: 29 IRI: 28 |
75 (71–85) | – | RAM + PTX; PTX; IRI | ORR, OS, PFS | – | Abstract |
| Kusumoto 2017 [38] | Japan | Retrospective observational study-cohort | NR |
RAM + PTX: 18 PTX: NR |
– | – | RAM + PTX; PTX | ORR, DCR, OS, PFS | AEs | Abstract |
| Non-controlled study | ||||||||||
| Sakai 2017 [36]b | Japan | Retrospective observational study-cohort | Single |
RAM + PTX: 20 RAM: 2 |
– | – | RAM + PTX; RAM | PFS | – | Abstract |
| Han 2021 [20] | Korea | Retrospective observational study-cohort | Multi | 1063 | 60 (1–88) | 724 (68.1) | RAM + PTX | ORR, DCR, OS, PFS (RECIST 1.1) | TRAEs (CTCAE 5.0) | Full text |
| Hashida 2021 [19] | Japan | Retrospective observational study-cohort | Single | 43 | 70 (36–90) | 28 (65.1) | RAM + nab-PTX | ORR, DCR, OS, PFS (RECIST 1.1) | AEs (CTCAE 4.0) | Full text |
| Komatsu 2021 [18] | Japan | Retrospective observational study-cohort | Multi | 3650 | – | 2677 (73.3) | RAM + taxane (PTX or nab-PTX) | – | – | Full text |
| Kim 2020 [25] | Korea | Prospective observational study-cohort | NR | 116 | 58 (47–63) | 71 (61.2) | RAM + PTX | ORR, DCR, OS, PFS (RECIST 1.1) | – | Full text |
| Sasaki 2020 [22] | Japan | Retrospective observational study-cohort | Single | 149 | – | 106 (71.1) | RAM + taxane (PTX or nab-PTX) | ORR, DCR, PFS (RECIST 1.1) | TRAEs (CTCAE 5.0) | Full text |
| Kashiwada 2019a [29] | Japan | Retrospective observational study-cohort | Single | 41 | – | – | RAM + PTX | OS, PFS | – | Abstract |
| Kashiwada 2019b [28] | Japan | Retrospective observational study-cohort | Single | 14 | – | – | RAM + nab-PTX | ORR, DCR, PFS | TRAEs | Abstract |
| Natsume 2019 [27] | Japan | Retrospective observational study-cohort | Single | 26 | 67 (40–81) | 8 (30.8) | RAM or RAM + PTX | ORR, OS, PFS (Subgroup- PlGF-low, PlGF-high)c (RECIST 1.1) | – | Full text |
| Fukuda 2018 [35] | Japan | Retrospective observational study-cohort | Single | 89 | 67 (35–83) | 47 (52.8) | RAM + PTX | ORR, DCR, OS, PFS (RECIST 1.1) | TRAEs (CTCAE 4.0) | Full text |
| Kusumoto 2018 [33] | Japan | Retrospective observational study-cohort | Single | 25 | – | – | RAM + PTX | ORR, DCR, OS, PFS | AEs | Abstract |
| Matsumoto 2017 [37] | Japan | Retrospective observational study-cohort | Single | 37 | – | – | RAM + PTX | ORR, OS, PFS | AEs | Abstract |
| Lim 2016 [41] | Korea | Retrospective observational study-cohort | NR | 70 | – | – | RAM + PTX | ORR, DCR, PFS | – | Abstract |
| Shinohara 2016 [40] | Japan | Retrospective observational study-case series | NR | 8 | – | – | RAM + PTX | ORR | AEs (CTCAE 4.0) | Abstract |
| Tozawa 2016 [39] | Japan | Retrospective observational study-cohort | NR | 20 | – | – | RAM + PTX | PFS | – | Abstract |
AEs adverse events, CTCAE Common Terminology Criteria for Adverse Events version, DCR disease control rate, IRI irinotecan, nab-PTX albumin-bound paclitaxel, NR not reported, ORR objective response rate, OS overall survival, PFS profession-free survival, PTX paclitaxel, RAM ramucirumab, RECIST response evaluation criteria in solid tumors, TRAEs treatment-related adverse events
aOkunaka 2020a (full text) and Okunaka 2020b (conference abstract) were multiple reports of the same study, and only the outcome data from Okunaka 2020a were included in the data analysis
bAlthough patients in Sakai 2017 received RAM or RAM + PTX, no result was reported in the original study about patients receiving RAM, so in this SLR, we deemed it non-controlled study
cData from Natsume 2019 were not included in the analysis because although patients were treated with RAM or RAM + PTX, no separate results were reported by intervention
dAll abstract studies were conference abstracts derived from the Japanese Society of Medical Oncology (JSMO) Annual Meeting, the European Society for Medical Oncology (ESMO) Congress, the ESMO World Congress on Gastrointestinal (GI) Cancer, the American Society of Clinical Oncology (ASCO) Annual Meeting, the ASCO Symposium on GI Cancer, and the Asia Pacific Digestive Week (APDW) Innovative Approaches to Gastroenterology