Findings

What do systematic reviews say?

2 questions · 2 findings · 1 reviews

No studies found 0 · 0%GRADE not reported 0 · 0%Very low 0 · 0%Low 0 · 0%Moderate 2 · 100%High 0 · 0%

Overall breast cancer incidence · women with above‐average risk of developing breast cancer

Tamoxifen probably leads to lower overall breast cancer incidence compared with placebo (moderate certainty).

1 finding from 1 review

Risk‐reducing medications for primary breast cancer: a network meta‐analysis 2019 · Cochrane Headline outcomes only
RR 0.68 [0.62, 0.76]
3 studies · 22832 participants
Moderate

Severe toxicity · women with above‐average risk of developing breast cancer

Tamoxifen probably leads to higher severe toxicity compared with placebo (moderate certainty).

1 finding from 1 review

Risk‐reducing medications for primary breast cancer: a network meta‐analysis 2019 · Cochrane Headline outcomes only
RR 1.28 [1.12, 1.47]
2 studies · 20361 participants
Moderate