SynthesisMedicine2022

Prognostic value of metformin in cancers: An updated meta-analysis based on 80 cohort studies.

Jing Yang, Hang Yang, Ling Cao, Yuzhen Yin, Ying Shen, Wei Zhu

Open access · goldAbstract readMeta-Analysis
In one paragraph

Synthesis in Medicine, 2022. The graph read 2 numbers from its abstract, feeding 1 cell of the map, but none could be read as for or against, so it casts no vote. It also reports 2 associations that do not count as treatment evidence, such as HR 0.76 (0.66 to 0.87) for all-cause mortality. Cited by 10 papers.

2numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed
1.2field-weighted citation impact, top 21% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

Read, but not usablea number the graph found but could not read as for or against

All-cause mortalityan association or prognostic statement, not a treatment comparison · t2dfeeds one cell of the map
HR 0.760.66 to 0.87
It showed that metformin was associated with better overall survival (hazard ratio [HR] = 0. 81; 95% confidence interval [CI]: [0.77-0.85]) and cancer-specific survival (HR = 0.79; 95% CI: [0.73-0.86]), and metformin was associated with progression-free survival (HR = 0.76; 95% CI: [0.66-0.87]).
All-cause mortalityan association or prognostic statement, not a treatment comparison · t2dfeeds one cell of the map
HR 0.790.73 to 0.86
It showed that metformin was associated with better overall survival (hazard ratio [HR] = 0. 81; 95% confidence interval [CI]: [0.77-0.85]) and cancer-specific survival (HR = 0.79; 95% CI: [0.73-0.86]), and metformin was associated with progression-free survival (HR = 0.76; 95% CI: [0.66-0.87]).

clause the extractor read what became the number

2 · Its place on the map

Where it lands on the map

Rows are treatments, columns are outcomes. The coloured squares are the cells this paper feeds, coloured by the vote it casts there. Click one to jump to what this paper adds to it.

supports the treatmentfavours the comparatorno clear differenceread, but no usable result
3 · What it changes

What it adds to each cell

For every cell the paper feeds: the belief in the claim with and without this paper, and this paper's estimate drawn against every other readable study in the cell. The ringed dot is this paper.

Metformin×all-cause mortality

No readable resultOpen on the map →What to test next →

1 readable study in this cell: 0 favour the treatment, 1 find no difference, 0 favour the comparator.

Belief with this paper
0.50one trial · 1 family supports, 0 contradict · against placebo
Without itNot a counted family in this claim, so removing it changes nothing.
← favours the treatmentfavours the comparator →
1 · no effect
NCT000387272,779 enrolled · 1996
HR 0.990.79 to 1.25

This paper's own estimate is on a different scale from the rest of the cell, so it is not drawn here.

4 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

5 · Its place in the literature

Who cites it

10 citing papers in PubMed, 15 citations in OpenAlex.

  1. Article
  2. Review
  3. Article
  4. Review
  5. Article
  6. Obesity and its management in primary care setting.Journal of diabetes and its complications · 2025
    Review
  7. Review
  8. Review
  9. Review
  10. Review
6 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

7 · Who and what money

Authors and funding

6 authors at 2 institutions in 3 countries.

Jing YangOncology Center, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Wujiang, Jiangsu Province, P.R. China.ORCID 0000-0002-7763-6571
Hang YangOncology Center, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Wujiang, Jiangsu Province, P.R. China.
Ling CaoOncology Center, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Wujiang, Jiangsu Province, P.R. China.
Yuzhen YinOncology Center, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Wujiang, Jiangsu Province, P.R. China.
Ying ShenDepartment of Endocrinology, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Wujiang, Jiangsu Province, P.R. China.
Wei ZhuDepartment of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, P.R. China.ORCID 0000-0002-5744-5962
West African Science Service Centre on Climate Change and Adapted Land Use · GHNanjing Medical University · CN

Funding

No grant is acknowledged in the PubMed record.

8 · The paper itself

Abstract

The marked sentences are the ones the graph read a number from.

backgroundExperiments have shown that metformin can inhibit cancer cell growth, but clinical observations have been inconsistent, so we pooled the currently available data to evaluate the impact of metformin on cancer survival and progression.

methodsPubMed, web of science, Embase, and Cochrane databases were searched. Pooled hazard ratios (HRs) were identified using a random-effects model to estimate the strength of the association between metformin and survival and progression in cancer patients.

resultsWe incorporated 80 articles published from all databases which satisfied the inclusion criterion. It showed that metformin was associated with better overall survival (hazard ratio [HR] = 0. 81; 95% confidence interval [CI]: [0.77-0.85]) and cancer-specific survival (HR = 0.79; 95% CI: [0.73-0.86]), and metformin was associated with progression-free survival (HR = 0.76; 95% CI: [0.66-0.87]). In patients with diabetes mellitus, the HR of overall survival was 0.79(95% CI: [0.75-0.83]), progression-free survival was 0.72(95% CI: [0.60-0.85]), and the cancer-specific survival was 0.76(95% CI: [0.68-0.86]). It was proposed that metformin can improve the prognosis of cancer patients with diabetes mellitus.

conclusionBased on cohort studies, metformin therapy has potential survival benefits for patients with malignancy, especially with the greatest benefits seen in breast cancer on overall survival, progression-free survival, and cancer-specific survival. And metformin also showed potential benefits in cancer-specific survival in colorectal and prostate cancer.

Indexed as

Breast NeoplasmsDiabetes MellitusMetforminCohort StudiesHumansHypoglycemic AgentsMalePrognosisHypoglycemic AgentsMetformin

Identifiers

PMID36626437
PMCPMC9750609
OpenAlexW4315435992

What Socratic holds

Texttitle and abstract
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.