Study reveals pregnancy reprograms breast cells, reducing cancer risk

An early age of pregnancy (25 years and younger) is known to reduce the overall risk of breast cancer by over 30%, suggests findings of a recent study.

CSHL Assistant Professor Camila dos Santos spent several years teasing out the molecular details behind the protective effects of pregnancy.

She discovered that one-way breast cells protect themselves from cancer after pregnancy in mice is to tuck away a particularly potent cancer gene, cMYC, where it cannot cause harm.

Another trick is to keep breast cells suspended in a state of "pre-senescence," a moment in the cell's life cycle between dying, living, and potential cancer.

These findings provide new insights into future cancer treatment and better ways to identify risk before a tumour develops.

Pregnancy blocks the deadly action of cMYC by rolling the gene away.

Dos Santos suggests a familiar image: Pregnancy turns off the cMYC gene and turns on another set of genes that promotes senescence.

Cells repeat the pattern open and closed DNA in subsequent pregnancies.