title: Intratumoral Immune Responses Can Distinguish New Primary and True Recurrence Types of Ipsilateral Breast Tumor Recurrences (IBTR).
abstract: Ipsilateral breast tumor recurrence (IBTR) is an increasingly common clinical challenge. IBTRs include True Recurrences (TR; persistent disease) and New Primaries (NP; de novo tumors), but discrimination between these is difficult. We assessed tumor infiltrating leukocytes (TIL) as biomarkers for distinguishing these types of IBTR using primary tumors and matched IBTRs from 24 breast cancer patients, half of which were identified as putative TRs and half as NPs using a previously reported clinical algorithm. Intratumoral lymphocyte populations (CD3, CD8, CD4, CD25, FOXP3, TIA1, CD20) and macrophages (CD68) were quantified by immunohistochemistry in each tumor. Compared to matched primaries, TRs showed significant trends towards increased CD3(+) and CD8(+) TIL, while these populations were often diminished in NPs. Comparison of IBTRs showed that TRs had significantly higher levels of CD3(+) (P = 0.0136), CD8(+) (P = 0.0092), and CD25(+) (P = 0.0159) TIL than NPs. We conclude that TIL may be a novel diagnostic biomarker to distinguish NP from TR IBTRs.
authors.affiliation: Deeley Research Centre, Vancouver Island Cancer Centre, British Columbia Cancer Agency, 2410 Lee Avenue, Victoria, BC, Canada, V8R 6V5.
authors.forename: Nathan R
authors.initials: NR
authors.lastname: West
authors.forename: Valerie
authors.initials: V
authors.lastname: Panet-Raymond
authors.forename: Pauline T
authors.initials: PT
authors.lastname: Truong
authors.forename: Cheryl
authors.initials: C
authors.lastname: Alexander
authors.forename: Sindy
authors.initials: S
authors.lastname: Babinszky
authors.forename: Katy
authors.initials: K
authors.lastname: Milne
authors.forename: Louetta A
authors.initials: LA
authors.lastname: Ross
authors.forename: Steven
authors.initials: S
authors.lastname: Loken
authors.forename: Peter H
authors.initials: PH
authors.lastname: Watson