PGR and neoplasm: After adjusting for baseline PgR status, tumor size, and age at diagnosis, the association between baseline proliferation and RFI remained non-significant IHC-Ki67 (HR = 1.76, 95 %CI: 0.23–13.50) and SSP-Ki67(HR = 0.65, 95 %CI: 0.21–2.03).