Study	Reason for exclusion
Ahn 2002	According to information provided by the first author about 2/3 of included participants had undergone gastric resection and were treated in adjuvant/additive intention.
Ajani 2002	Article about study published elsewhere (Van Cutsem 2006).
Ajani 2006	Non‐randomised phase II study.
Akagi 2010	Other indication (patients underwent macroscopically curative resection).
Akazawa 1985	Study not randomised.
Andrić 2012	Interventions not relevant for any of the comparisons specified.
Anonymous 1979	Not all participants were randomised (some were directly assigned to 1 treatment arm according to their prior chemotherapy). Systematic cross‐over between treatment arms.
Anonymous 1982	Study began as three‐arm comparison of FAMe, FAMi and FIMe regimens. FMe was added to randomization later. ICRF‐159 =dexrazoxaneL None of the possible permutations between these regimens fit our study comparisons
Anonymous 1983	18 of 82 included participants were crossed over (< 10 %)
Anonymous 1984	Compared FA, FAMe, and FAMi. None of the possible permutations between these regimens fit our study comparisons.
Aoyama 1981	Study not randomised
Bajetta 1998	Participants not randomised to different chemotherapy regimens, but to one regimen (FEP) with or without GM‐CSF
Baker 1976	Participants with different advanced gastrointestinal cancers were included in the study. No separate results given for gastric cancer participants.
Balana 1990	Preliminary publication.
Berenberg 1989	Final publication: Berenberg 1995 (excluded).
Berenberg 1995	Compares different single‐agent chemotherapy regimens.
Beretta 1983	Published as abstract only. No further information obtained by contacting the first author.
Beretta 1989	Published as abstract only. No further information obtained by contacting the first author.
Berglund 2006	Other indications.
Bi 2011	Cross‐over study.
Bjerkeset 1986	Study included participants with different advanced gastrointestinal cancers. No separate results given for gastric cancer participants.
Bruckner 1986	Preliminary publication.
Brugarolas 1975	Study published as abstract only with insufficient data available. According to information provided by the first author no further analysis was performed as the study was terminated early due to slow accrual.
Bugat 2003	Secondary publication.
Buroker 1979	Does not compare different intravenous combination chemotherapy regimens but 1 intravenous regimen with or without an additional oral chemotherapy (methyl‐CCNU).
Cai 2011	Not an RCT, retrospective analysis of an RCT.
Cascinu 1994	Final publication: Cascinu 1995 (excluded).
Cascinu 1995	Participants not randomised to different chemotherapy regimens but to reduced glutathione or placebo to prevent cisplatin‐induced neurotoxicity.
Cascinu 1996	Participants not randomised to different chemotherapy regimens but to different doses of G‐CSF as supportive therapy.
Chau 2013	Testing VEGF inhibitor (ramucirumab) as second‐line therapy.
Chen 2011	Gimeracil + oteracil, neither contains a 5‐FU prodrug nor is equivalent to S‐1. So this combination does not fit any comparison.
Chlebowski 1979	One study arm was treated with oral 5‐FU.
Chlebowski 1985	Insufficient information for calculation of HRs given in the publication or provided by the author.
Chu 2006	Missing information to calculate HRs for OS
Chung 2011	Not an RCT.
Coates 1984	Included 108 participants with advanced cancer (only 5 gastric cancer patients).
Cocconi 1982	Systematic cross‐over between study groups (< 10 % of included participants).
Cocconi 1992	Final publication: Cocconi 1994 (included).
Colucci 1991	Final publication: Colucci 1995 (included).
Constenla 2002	Study not randomised.
Coombes 1994	Compares different single agents.
Cullinan 1993	Final publication: Cullinan 1994 (included).
Cunningham 2008	Wider indication (inclusion of patients with squamous cell carcinoma of the oesophagus as well).
De Lisi 1985	Final publication: De Lisi 1986 (included).
De Lisi 1988	Second publication to De Lisi 1986 (included).
Diaz‐Rubio 1991	Preliminary publication.
Douglass 1983	Final publication: Douglass 1984 (excluded).
Douglass 1984	Not all participants were randomised. Some were directly assigned to 1 study arm according to their prior treatment.
Duffour 2006	Interventions not relevant for any of the comparisons specified.
Figoli 1991	Study not randomised. Two consecutive regimens were compared.
Ford 2014	Second‐line CTX.
Fuchs 2014	Testing VEGF inhibitor (ramucirumab) as second‐line therapy.
Fujii 1983	Study not randomised.
Furue 1985	Schizophyllan: mushroom polysaccharide with immunomodulatory properties (biologic therapy), no chemotherapy.
Furukawa 1995	Although described as advanced gastric cancer in the title, according to the text of the article the study compared different adjuvant chemotherapy regimens.
Gao 2010	inclusion pf patients with squamous epithelium carcinoma.
Gioffre 1984	Study not randomised.
Glimelius 1994	Final publication: Glimelius 1997 (excluded).
Glimelius 1995	Study includes participants with different inoperable cancers. Cross‐over from BSC to chemotherapy arm permitted. Primary aim: cost‐effectiveness.
Glimelius 1997	Study compares chemotherapy versus best supportive care. Provision of chemotherapy upon request in the best supportive care group was requested by the research ethics committee, and 12 of 30 participants (19.6%) randomised to best supportive care finally received chemotherapy (cross‐over).
Goseki 1995	Participants were not randomised between different chemotherapy regimens but to methionine‐depleted total parenteral nutrition versus a conventional amino acid solution.
Grau 1988	All participants were treated with chemotherapy after resection (no advanced/metastatic disease).
Grieco 1984	Study not randomised.
Gubanski 2010	Prescheduled cross‐over between study arms after four courses.
Guimbaud 2014	Considerable use of second‐line therapy.
Gupta 1982	Insufficient data on survival available.
Haas 1983	Cross‐over after failure was encouraged.
Hawkins 2003	Preliminary data.
Hoffman 1998	Retrospective analysis of clinical benefit and quality of life in participants with different inoperable gastrointestinal cancers.
Icli 1993	Study not randomised.
Imada 1999	Includes participants treated in adjuvant intention after curative resection of gastric cancer.
Inoue 1989	Participants with ascites were treated with intraperitoneal chemotherapy.
Jeung 2011	Interventions not relevant for any of the comparisons specified.
Kang 2007	Interventions not relevant for any of the comparisons specified.
Kelsen 1990	Preliminary publication.
Kilickap 2011	Not an RCT.
Kim 1991	Final publication: Kim 1993 (excluded).
Kim 1993	According to information provided by author (YSP) allocation was done by alternation (not truly randomised).
Kim 2012	Interventions not relevant for any of the comparisons specified.
Kim 2013	Meta‐analysis is examining second‐line therapy vs BSC.
Kitamura 1995	Study compares the effect of different amino‐acid solutions (methionine‐free amino‐acid solution versus commercial amino‐acid solution) in addition to 5‐FU chemotherapy.
Koizumi 1996	Compares different dosages of cisplatin (60 mg and 80 mg) within the same chemotherapy regimen.
Koizumi 2004	Interventions not relevant for any of the comparisons specified.
Koizumi 2012	Not an RCT.
Koizumi 2013	Testing irinotecan plus cisplatin versus irinotecan as second‐line therapy.
Kolaric 1986	Participants with stomach and rectosigmoid cancer included. No separate information about gastric cancer provided.
Kondo 2000	Study uses oral 5‐FU (no intravenous chemotherapy, varying bioavailability).
Kono 2002	Study treatment: adoptive immunotherapy.
Kornek 2002	Does not compare different chemotherapy regimens but the same chemotherapy with or without G‐CSF and/or erythropoietin.
Kosaka 1995	One group was treated with intra‐arterial chemotherapy.
Kovach 1974	Insufficient data for calculation of HRs given (P value missing).
Kuitunen 1991	Final publication: Pyrhönen 1995 (included).
Kurihara 1991	Compared: tegafur + mitomycin C (FTM), uracil‐tegafur + mitomycin C (UFTM), 5'deoxy‐flurorouridine + cisplatin (5'P), etoposide + doxorubicin + cisplatin (EAP), and 5‐fluorouracil + cisplatin (FP). Firstly, none of the possible permutations between these regimens fit our study comparisons. Secondly, the Ohkuwa 2000 paper resembles a “pooled ” analysis (of other RCTs such as Kurihara 1991) rather than an original RCT.
Kurihara 1995	Participants randomised to either methionine‐free or commercial amino‐acid solution, with the same (mitomycin C/fluorouracil) chemotherapy in both groups.
Kurihara 1995a	Final publication: Koizumi 1996 (excluded).
Lacave 1985	Final publication: Lacave 1987 (excluded).
Lacave 1987	Does not compare different intravenous chemotherapy regimens but 1 intravenous chemotherapy with or without an additional oral chemotherapy (methyl‐CCNU).
Lee 2008	Interventions not relevant for any of the comparisons specified.
Lee 2012	Gastrointestinal endoscopy.
Levard 1998	Participants had oesophageal squamous cell carcinoma.
Li 2002	Drug under investigation was never approved, and the regimen does not fit any of our 10 comparisons. Also their trial was not solely done in gastric cancer patients, but also included patients with colorectal, oesophageal, and liver cancer.
Li 2007	Missing information to calculate HRs for OS.
Li 2011	Not relevant for any of the comparisons.
Li 2013	Testing second‐line apatinib.
Lim 2011	Not relevant for any of the comparisons.
Livstone 1977	Radiochemotherapy is compared to systemic intravenous chemotherapy.
Lordick 2013	Testing whether cetuximab (EGFR targeted mAB) should be included as first‐line in combination with capecitabine and cisplatin.
Lorenzen 2007	Not a randomised trial.
Luelmo 2006	Interventions not relevant for any of the comparisons specified.
Malik 1990	Study not randomised. Includes participants with gastric and colorectal cancer.
Maruta 2007	Second‐line chemotherapy.
Massuti 1994	Published as abstract only. No further information obtained by contact with the first author.
Massuti 1995	Published as abstract only. No further information obtained by contact with the first author.
Mochiki 2012	Interventions not relevant for any of the comparisons specified.
Moertel 1976	Insufficient information for calculation of HRs given.
Moertel 1979	The combination therapy arm consisted of only 1ne oral agent (methyl‐CCNU, no intravenous chemotherapy), in addition to 5‐FU which was used as single‐agent.
Moertel 1979a	Not all participants were randomised (some were directly assigned to 1 treatment arm according to their prior treatment). Systematic cross‐over between study groups.
Moore 2005	Secondary publication.
Mustacchi 1997	Study included participants with different advanced cancers (only 3 patients with gastric cancer).
Nakajima 1984	Study compares different adjuvant chemotherapies.
Nakao 1983	Study treatment included schizophyllan (mushroom polysaccharide with immunomodulatory effects, biological therapy).
Nakashima 2008	The treatment for each patient was decided by the patient’s choice or randomisation (not a randomised trial).
Niitani 1987	Compares different modes of application of the same chemotherapy (continuous and intermittent oral administration of 5´deoxy‐5‐fluorouridine), not different chemotherapy regimens.
Nordin 2001	Study presents different interpretations of quality of life data from a previously performed study (Glimelius 1997). The study included advanced gastric cancer participants, but was excluded because of cross‐over.
Novik 1999	Compares different single agents.
Ohtsu 2011	Testing whether bevacizumab (VEGF targeted mAB) should be included in first‐line chemotherapy combinations.
Okines 2010	Not an RCT.
Osawa 1996	Study treatment: adjuvant chemo‐immunotherapy.
Pannettiere 1984	Compares 2 modes of application (sequential versus simultaneous) of 1 chemotherapy regimen (FAM).
Park 2004	Interim analysis of Park 2006.
Park 2006	Interventions not relevant for any of the comparisons specified.
Park 2008	Interventions not eligible for any of the comparisons specified.
Popliela 1982	Study treatment: chemo‐immunotherapy.
Popov 1999	Final publication: Popov 2000 (excluded).
Popov 2000	Compares different applications of doxorubicin (bolus versus 8‐hour infusion) in the same chemotherapy regimen (EAP), not different chemotherapy regimens.
Pozzo 2004	Interventions not relevant for any of the comparisons specified.
Pyrhonen 1992	Final publication: Pyrhönen 1995 (included).
Queisser 1984	Compared 5‐fluorouracil and carmustine with or without adriamycin. This does not fit our study comparisons.
Rake 1979	39 of 77 included participants receiving chemotherapy as additive therapy after non‐curative resection with histological evidence of residual disease.
Roth 1994	Final publication: Roth 1999 (included).
Roth 1995	Final publication: Roth 1999 (included).
Roth 1997	Final publication: Roth 1999 (included).
Sakata 1982	Participants were treated with OK‐432 (streptococcal preparation, biological response modifier).
Sakata 1988	Study included participants with various gastrointestinal tumors, which were treated with a biological therapy.
Sakata 1992	Study included participants with different adenocarcinomas.
Sasagawa 1994	Insufficient information for calculation of HRs given.
Sasaki 1989	Publication presents only preliminary results of this study. No information about final results provided by the first author.
Sasaki 1990	Study not randomised.
Sasaki 1992	Study includes participants with colorectal and gastric cancer. Insufficient information given about results in gastric cancer.
Sasaki 1995	Study includes participants with colorectal and gastric cancer. Insufficient information given about results in gastric cancer.
Sato 1991	Study summarises the experience of angiotensin II‐induced hypertension to enhance drug delivery for chemotherapy. Participants were not randomised to different chemotherapy regimens.
Sato 1995	Participants were not randomised to different chemotherapy regimens but to angiotensin II‐induced hypertension to enhance chemotherapy effects or control.
Satoh 2013	Text needed.
Satoh 2014	Testing whether lapatinib (HER2 inhibitor) should be used in second‐line therapy in HER2‐amplified Asian population.
Schmid 2003	Study not randomised.
Shen 2009	No information on overall survival.
Shin 2007	Interventions not relevant for any of the comparisons specified.
Shinoda 1995	Reporting standards to be insufficient and/or the dose schedule to be different from other studies.
Shu 1999	Study compared the effect of intraperitoneal combined with intravenous to only intravenous chemotherapy.
Shudong 1996	Insufficient information for calculation of HRs given.
Smith 1983	Study included various advanced adenocarcinomas of the gastrointestinal tract (only 5 participants with gastric cancer).
Sun 2004	Interventions not relevant for any of the comparisons specified (radiochemotherapy).
Sym 2013	A study in participants refractory to first‐line chemotherapy ‐ thus no first‐line treatment.
Taal 1990	Study not randomised.
Taguchi 1985	Study treatment includes lentinan (mushroom polysaccharide with immunomodulatory properties, biological therapy).
Takahashi 1991	Study participants had resectable tumours. One group received intraarterial chemotherapy.
Tebbutt 2002	Not eligible for any of the comparisons specified.
Tebbutt 2007	Not relevant for any of the comparisons (docetaxel in both treatment arms).
Tebbutt 2010	Included esophageal cancer patients.
Thuss‐Patience 2011	Second‐line therapy.
Tsushima 1991	Study treatment includes OK (streptococcal preparation, biologic response modifier).
Van Cutsem 2009	Targeted therapy.
Vanhoefer 2000	Compared methotrexate, fluorouracil, and doxorubicin versus etoposide, leucovorin, and fluorouracil versus infusional fluorouracil and cisplatin. None of the possible permutations between these regimens fit our study comparisons
Vaughn 1980	Study included participants with advanced gastrointestinal malignancies (only 11 participants with gastric cancer).
Vestlev 1990	Inconclusive data (time to progression and survival identical).
Villar 1987	Study included participants (13 of 46) with only microscopic disease in the resection margins.
Voznyi 1978	One study arm consisted only of oral chemotherapy (CCNU). Two other of 5 study arms differed from others only in the addition of oral CCNU (does not compare different intravenous chemotherapy regimens).
Wadler 2002	Study treatment includes interferon and filgrastim (biological therapy).
Wakui 1983	Participants had various gastrointestinal malignancies. Therapy includes levamisole (antihelmintic drug with immunomodulatory properties).
Wakui 1983a	Participants had various gastrointestinal malignancies. Therapy included levamisole (antihelmintic drug with immunomodulatory properties).
Wakui 1986	Study treatment includes lentinan (mushroom polysaccharide with immunomodulatory properties, biological therapy).
Wang 2007	Not relevant for any of the comparisons.
Waters 1999	Paper reports long‐term follow‐up of the study published by Webb 1997 (included)
Wilke 2014	Testing VEGF inhibitor (ramucirumab) as second‐line therapy.
Wils 1991	Compared 5‐fluorouracil, adriamycin and methotrexate vs 5‐fluorouracil, adriamycin and mitomycin‐C. This does not fit our study comparisons
Wils 1994	Published as abstract only, no further information about final results obtained by contacting the first author.
Xu 2013	Tested recombinant human endostatin, and regimen does not fit our comparisons.
Yamada 1994	According to information provided by the first author the study was not randomised.
Yin 1996	Study treatment includes Elemene (product isolated from the Chinese medical herb Rhizoma zedoariae, biological therapy).
Yoshida 2003	Compares the feasibility of personalised chemotherapy (according to the expression of molecular markers) with standard therapy.
Yoshikawa 2011	Tested a chemoimmunotherapy combination.
Yoshino 2007	Intervention not eligible for any of the comparisons specified.
Yun 2010	Intervention not eligible for any of the comparisons specified.
Zhao 2009	missing information to calculate HRs for OS.
Zironi 1992	Final publication: Cocconi 1994 (included)

5‐FU: 5‐Fluorouracil
 A: adriamycin (also known as doxorubicin)
 BSC: best supportive care
 CTX: chemotherapy
 FA: folinic acid
 FAMe: 5‐FU 325mg/m² d 1‐5, A 40mg/m² d 1 until d 36, Me 110mg/m² orally at d 1 repeated at d 71
 FAMi: 5‐FU 275mg/m² d 1‐5, A 30mg/m² d 1 until d 36, M 10mg/m² d1 repeated at d 71
 FIMe: 5‐FU 325mg/m² d 1‐5 repeated at d 36, ICRF‐159 500mg/m² orally at d 2‐4 and d 36‐38, Me 110mg/m² orally at d 1 repeated at d 71
 FMe: 5‐FU 300 mg/m² d 1‐5 repeated at d 36, Me 175 mg/m² orally at d 1 repeated at d 50
 G‐CSF: granulocyte‐macrophage colony‐stimulating factor
 HR: hazard ratio
 ICRF: razoxane
 M: mitomycin C
 Me: semustine (also known as methyl‐CCNU)
 OS: overall survival
 RCT: randomised controlled trial
 VEGF: vascular endothelial growth factor