What do systematic reviews say?

Chemotherapy vs chemotherapy alone

Chemotherapy showed no clear difference in overall survival (non‐taxane monotherapy vs taxane monotherapy) compared with chemotherapy (low certainty).

• Salvage systemic therapy for advanced gastric and oesophago‐gastric junction adenocarcinoma 2020 · Cochrane Headline outcomes only
  HR 1.13 [0.86, 1.48]
  1 study · 219 participants
  Low

Chemotherapy vs chemotherapy alone

Chemotherapy showed no clear difference in overall survival (taxane‐containing doublet therapy vs taxane… compared with chemotherapy (low certainty).

• Salvage systemic therapy for advanced gastric and oesophago‐gastric junction adenocarcinoma 2020 · Cochrane Headline outcomes only
  HR 1.05 [0.72, 1.54]
  2 studies · 121 participants
  Low

Chemotherapy vs chemotherapy alone

• Salvage systemic therapy for advanced gastric and oesophago‐gastric junction adenocarcinoma 2020 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 107 participants
  High

Chemotherapy vs biological therapy

Chemotherapy showed no clear difference in overall survival compared with biological therapy (moderate certainty).

• Salvage systemic therapy for advanced gastric and oesophago‐gastric junction adenocarcinoma 2020 · Cochrane Headline outcomes only
  HR 0.82 [0.66, 1.02]
  1 study · 395 participants
  Moderate

Concomitant (concurrent) chemoradiotherapy vs chemoradiotherapy plus surgery

Chemoradiotherapy showed no clear difference in overall survival compared with chemoradiotherapy plus surgery (high certainty).

• Chemoradiotherapy versus chemoradiotherapy plus surgery for esophageal cancer 2017 · Cochrane Headline outcomes only
  HR 0.99 [0.79, 1.24]
  2 studies · 431 participants
  High

Delayed chemotherapy vs immediate chemotherapy

Delayed chemotherapy showed no clear difference in overall survival compared with immediate chemotherapy (low certainty).

• Survival differences with immediate versus delayed chemotherapy for asymptomatic incurable metastatic colorectal cancer 2018 · Cochrane Headline outcomes only
  HR 1.17 [0.93, 1.46]
  3 studies · 351 participants
  Low

Perioperative chemotherapy vs primary surgery

Perioperative chemotherapy leads to lower overall survival by chemo‐/radiotherapy ‐ Chemotherapy only compared with primary surgery (high certainty).

• Perioperative chemo(radio)therapy versus primary surgery for resectable adenocarcinoma of the stomach,… 2013 · Cochrane Headline outcomes only
  HR 0.83 [0.75, 0.91]
  10 studies · 2033 participants
  High

Perioperative chemotherapy vs primary surgery

Perioperative chemotherapy probably leads to lower overall survival by chemo‐/radiotherapy ‐ Chemoradiotherapy compared with primary surgery (moderate certainty).

• Perioperative chemo(radio)therapy versus primary surgery for resectable adenocarcinoma of the stomach,… 2013 · Cochrane Headline outcomes only
  HR 0.7 [0.5, 0.99]
  4 studies · 389 participants
  Moderate

Anti‐angiogenic therapy vs no anti‐angiogenic therapy

Anti‐angiogenic therapy showed no clear difference in overall survival ( compared with no anti‐angiogenic therapy (high certainty).

• Anti‐angiogenic therapy for high‐grade glioma 2018 · Cochrane Headline outcomes only
  HR 0.95 [0.88, 1.02]
  11 studies · 3743 participants
  High
• Anti‐angiogenic therapy for high‐grade glioma 2018 · Cochrane Headline outcomes only
  HR 0.93 [0.86, 1.02]
  8 studies · 2833 participants
  High
• Anti‐angiogenic therapy for high‐grade glioma 2018 · Cochrane Headline outcomes only
  HR 0.99 [0.85, 1.16]
  3 studies · 910 participants
  Moderate

Bevacizumab plus chemotherapy vs chemotherapy alone

Chemotherapy + bevacizumab leads to lower overall survival compared with chemotherapy (high certainty).

• Second‐line systemic therapy for metastatic colorectal cancer 2017 · Cochrane Headline outcomes only
  HR 0.79 [0.7, 0.88]
  4 studies · 1723 participants
  High

Cediranib plus chemotherapy vs placebo plus chemotherapy

Cediranib plus chemotherapy showed no clear difference in overall survival compared with placebo plus chemotherapy (low certainty).

• Vascular endothelial growth factor (VEGF) targeting therapy for persistent, recurrent, or metastatic cervical cancer 2021 · Cochrane Headline outcomes only
  HR 0.94 [0.53, 1.65]
  1 study · 69 participants
  Low

Extended‐field radiotherapy vs pelvic radiotherapy

Extended‐field radiotherapy probably leads to lower overall survival compared with pelvic radiotherapy (moderate certainty).

• Extended‐field radiotherapy for locally advanced cervical cancer 2018 · Cochrane Headline outcomes only
  HR 0.67 [0.48, 0.94]
  1 study · 337 participants
  Moderate

Extended‐field radiotherapy vs pelvic chemoradiotherapy

Extended‐field radiotherapy probably leads to lower overall survival compared with pelvic chemoradiotherapy (moderate certainty).

• Extended‐field radiotherapy for locally advanced cervical cancer 2018 · Cochrane Headline outcomes only
  HR 0.5 [0.39, 0.64]
  1 study · 389 participants
  Moderate

Bevacizumab plus chemotherapy vs chemotherapy alone

Bevacizumab plus chemotherapy may leads to lower overall survival compared with chemotherapy (low certainty).

• Vascular endothelial growth factor (VEGF) targeting therapy for persistent, recurrent, or metastatic cervical cancer 2021 · Cochrane Headline outcomes only
  HR 0.77 [0.62, 0.95]
  1 study · 452 participants
  Low

Hypofractionated radiotherapy vs radiotherapy

Hypofractionated radiotherapy showed no clear difference in overall survival compared with conventional radiotherapy (moderate certainty).

• Radiotherapy for diffuse brainstem glioma in children and young adults 2016 · Cochrane Headline outcomes only
  HR 1.03 [0.53, 2.01]
  1 study · 71 participants
  Moderate

Low‐dose adjuvant radiotherapy vs standard‐dose adjuvant radiotherapy

The review found no eligible studies for this question.

• De‐intensified adjuvant (chemo)radiotherapy versus standard adjuvant chemoradiotherapy post transoral minimally… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Hyperfractionated radiotherapy vs radiotherapy

Hyperfractionated radiotherapy showed no clear difference in overall survival compared with conventional radiotherapy (low certainty).

• Radiotherapy for diffuse brainstem glioma in children and young adults 2016 · Cochrane Headline outcomes only
  HR 1.07 [0.75, 1.53]
  1 study · 130 participants
  Low

Extended‐field chemoradiotherapy vs pelvic chemoradiotherapy

It is very uncertain whether extended‐field chemoradiotherapy changes overall survival compared with pelvic chemoradiotherapy (very low certainty).

• Extended‐field radiotherapy for locally advanced cervical cancer 2018 · Cochrane Headline outcomes only
  HR 0.37 [0.14, 0.96]
  1 study · 74 participants
  Very low

Biochemotherapy vs chemotherapy alone

Biochemotherapy showed no clear difference in overall survival† compared with chemotherapy (high certainty).

• Systemic treatments for metastatic cutaneous melanoma 2018 · Cochrane Headline outcomes only
  HR 0.94 [0.84, 1.06]
  1317 participants
  High

Chemotherapy vs placebo, best supportive care (BSC) or no treatment

Chemotherapy probably leads to lower overall survival compared with placebo, best supportive care (BSC) or no treatment (moderate certainty).

• Salvage systemic therapy for advanced gastric and oesophago‐gastric junction adenocarcinoma 2020 · Cochrane Headline outcomes only
  HR 0.66 [0.52, 0.83]
  2 studies · 547 participants
  Moderate