Cochrane · systematic review · CD005195
Selenium for preventing cancer
Vinceti, M, Filippini, T, Del Giovane, C, et al. · Cochrane Database of Systematic Reviews · 2018 · Cochrane Library
Gynaecological, Neuro-oncology and Orphan CancerAMSTAR 2: not assessed
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
15
current version
GRADE rated
15
No studies
0
Included studies
NR
No studies 0 · 0%Ungraded 0 · 0%Very low 7 · 46.7%Low 0 · 0%Moderate 2 · 13.3%High 6 · 40%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Questions and results
Highest compared with lowest selenium exposure for preventing cancer in randomised controlled studies with low risk of bias
Population: Participants in trials with low risk of bias
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Any cancer risk No. of participants: 19,475 (3 RCTs) Highest vs lowest selenium exposure | RR 1.01 [0.93, 1.1] | NR | High |
Cancer mortality risk No. of participants: 17,448 (1 RCT) Highest vs lowest selenium exposure | RR 1.02 [0.8, 1.3] | NR | High |
Colorectal cancer risk No. of participants: 19,009 (2 RCTs) Highest vs lowest selenium exposure | RR 0.99 [0.69, 1.43] | NR | High |
Non‐melanoma skin cancer risk No. of participants: 2027 (2 RCTs) Highest vs lowest selenium exposure | RR 1.16 [0.3, 4.42] | NR | Moderate Downgraded: inconsistency |
Lung cancer risk No. of participants: 19,009 (2 RCTs) Highest vs lowest selenium exposure | RR 1.16 [0.89, 1.5] | NR | High |
Breast cancer risk No. of participants: 802 (1 RCT) Highest vs lowest selenium exposure | RR 2.04 [0.44, 9.55] | NR | Moderate Downgraded: imprecision |
Bladder cancer risk No. of participants: 19,009 (2 RCTs) Highest vs lowest selenium exposure | RR 1.07 [0.76, 1.52] | NR | High |
Prostate cancer risk No. of participants: 18,942 (4 RCTs) Highest vs lowest selenium exposure | RR 1.01 [0.9, 1.14] | NR | High |
Highest compared with lowest selenium exposure for preventing cancer in observational studies
Population: Participants in non experimental cohort studies on selenium and cancer
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Any cancer risk No. of participants: 76,239 (7 observational studies) Highest vs lowest selenium exposure | OR 0.72 [0.55, 0.93] | NR | Very low Downgraded: risk of bias |
Cancer mortality risk No. of participants: 183,863 (7 observational studies) Highest vs lowest selenium exposure | OR 0.76 [0.59, 0.97] | NR | Very low Downgraded: risk of bias |
Colorectal cancer risk No. of participants: 712,746 (6 observational studies) Highest vs lowest selenium exposure | OR 0.82 [0.72, 0.94] | NR | Very low Downgraded: risk of bias |
Lung cancer risk No. of participants: 371,067 (11 observational studies) Highest vs lowest selenium exposure | OR 0.82 [0.59, 1.14] | NR | Very low Downgraded: risk of bias, imprecision, inconsistency |
Breast cancer risk (women) No. of participants: 169,028 (8 observational studies) Highest vs lowest selenium exposure | OR 1.09 [0.87, 1.37] | NR | Very low Downgraded: risk of bias, imprecision |
Bladder cancer risk No. of participants: 279,100 (5 observational studies) Highest vs lowest selenium exposure | OR 0.67 [0.46, 0.97] | NR | Very low Downgraded: risk of bias, imprecision |
Prostate cancer risk No. of participants: 576,667 (21 observational studies) Highest vs lowest selenium exposure | OR 0.84 [0.75, 0.95] | NR | Very low Downgraded: risk of bias, publication bias |