During pregnancy and lactation, the levels of hormones such as estrogen, progesterone, insulin-like growth factor 1, prolactin, and oxytocin increase, that can increase tumor cell proliferation.[14,15] A weakened immune system during pregnancy and breast remodeling can also affect cancer growth and metastasis.[12] However, despite several studies, the results are inconsistent owing to small population sizes and discrepancies in study methods.[16] Therefore, the notion that PABC itself is associated with poor prognosis remains debatable.[17]. This evidence concerns the gene IGF1 and cancer.