Can breastfeeding reduce the risk of breast cancer?

Breastfeeding can reduce the risk of developing breast cancer, but requires breastfeeding to be continuous for a relatively long time.

Sources:
https://www.mdanderson.org/publications/focused-on-health/breastfeeding-breast-cancer-prevention.h19-1589046.html
https://www.ncbi.nlm.nih.gov/pubmed/12133652?dopt=Abstract