TILs Immunophenotype in Breast Cancer Predicts Local Failure and Overall Survival: Analysis in a Large Radiotherapy Trial with Long-Term Follow-Up

Ewan Millar; Lois Browne; Iveta Slapetova; Fei Shang; Yuqi Ren; Rachel Bradshaw; Heather Ann Brauer; Sandra O'Toole; Julia Beretov; Renee Whan; Peter H Graham

doi:10.3390/cancers12092365

TILs Immunophenotype in Breast Cancer Predicts Local Failure and Overall Survival: Analysis in a Large Radiotherapy Trial with Long-Term Follow-Up

Cancers (Basel). 2020 Aug 21;12(9):2365. doi: 10.3390/cancers12092365.

Authors

Ewan Millar^{1

2

3}, Lois Browne⁴, Iveta Slapetova⁵, Fei Shang⁵, Yuqi Ren⁶, Rachel Bradshaw⁶, Heather Ann Brauer⁶, Sandra O'Toole^{7

8

9}, Julia Beretov^{1

2

4}, Renee Whan⁵, Peter H Graham^{2

4}

Affiliations

¹ Department of Anatomical Pathology, NSW Health Pathology, St George Hospital, Kogarah, NSW 2217, Australia.
² Faculty of Medicine, St George & Sutherland Clinical School, University of New South Wales Sydney, Kensington, NSW 2052, Australia.
³ Faculty of Medicine & Health Sciences, Sydney Western University, Campbelltown, NSW 2560, Australia.
⁴ Cancer Care Centre, St George Hospital, Kogarah, NSW 2217, Australia.
⁵ Biomedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales Sydney, Kensington, NSW 2052, Australia.
⁶ NanoString Technologies Inc., Seattle, WA 98109, USA.
⁷ Department of Anatomical Pathology, NSW Health Pathology, Royal Prince Alfred Hospital, Camperdown, NSW 2217, Australia.
⁸ Garvan Institute of Medical Research, Victoria Street, Darlinghurst, NSW 2010, Australia.
⁹ Faculty of Medicine, University of Sydney, Camperdown, NSW 2050, Australia.

Abstract

Aim: To determine the prognostic significance of the immunophenotype of tumour-infiltrating lymphocytes (TILs) within a cohort of breast cancer patients with long-term follow-up.

Methods: Multiplexed immunofluorescence and automated image analysis were used to assess the expression of CD3, CD8, CD20, CD68, Fox P3, PD-1 and PD-L1 in a clinical trial of local excision and radiotherapy randomised to a cavity boost or not (n = 485, median follow-up 16 years). Kaplan-Meier and Cox multivariate analysis (MVA) methodology were used to ascertain relationships with local recurrence (LR), overall survival (OS) and disease-free survival (DFS). NanoString BC360 gene expression panel was applied to a subset of luminal patients to identify pathways associated with LR.

Results: LR was predicted by low CD8 in MVA in the whole cohort (HR 2.34, CI 1.4-4.02, p = 0.002) and luminal tumours (HR 2.19, CI 1.23-3.92, p = 0.008) with associations with increased stromal components, decreased Tregs (FoxP3), inflammatory chemokines and SOX2. Poor OS was associated with low CD20 in the whole cohort (HR 1.73, CI 1.2-2.4, p = 0.002) and luminal tumours on MVA and low PD-L1 in triple-negative cancer (HR 3.44, CI 1.5-7, p = 0.003).

Conclusions: Immunophenotype adds further prognostic data to help further stratify risk of LR and OS even in TILs low-luminal tumours.

Keywords: breast cancer; immunophenotype; prognosis; tumour infiltrating lymphocytes (TILs).