The tale of TILs in breast cancer: A report from The International Immuno-Oncology Biomarker Working Group.
Khalid El Bairi,
Harry R Haynes,
Elizabeth Blackley,
Susan Fineberg,
Jeffrey Shear,
Sophia Turner,
Juliana Ribeiro de Freitas,
Daniel Sur,
Luis Claudio Amendola,
Masoumeh Gharib,
Amine Kallala,
Indu Arun,
Farid Azmoudeh-Ardalan,
Luciana Fujimoto,
Luz F Sua,
Shi-Wei Liu,
Huang-Chun Lien,
Pawan Kirtani,
Marcelo Balancin,
Hicham El Attar,
Prerna Guleria,
Wenxian Yang,
Emad Shash,
I-Chun Chen,
Veronica Bautista,
Jose Fernando Do Prado Moura,
Bernardo L Rapoport,
Carlos Castaneda,
Eunice Spengler,
Gabriela Acosta-Haab,
Isabel Frahm,
Joselyn Sanchez,
Miluska Castillo,
Najat Bouchmaa,
Reena R Md Zin,
Ruohong Shui,
Timothy Onyuma,
Wentao Yang,
Zaheed Husain,
Karen Willard-Gallo,
An Coosemans,
Edith A Perez,
Elena Provenzano,
Paula Gonzalez Ericsson,
Eduardo Richardet,
Ravi Mehrotra,
Sandra Sarancone,
Anna Ehinger,
David L Rimm,
John M S Bartlett,
Giuseppe Viale,
Carsten Denkert,
Akira I Hida,
Christos Sotiriou,
Sibylle Loibl,
Stephen M Hewitt,
Sunil Badve,
William Fraser Symmans,
Rim S Kim,
Giancarlo Pruneri,
Shom Goel,
Prudence A Francis,
Gloria Inurrigarro,
Rin Yamaguchi,
Hernan Garcia-Rivello,
Hugo Horlings,
Said Afqir,
Roberto Salgado,
Sylvia Adams,
Marleen Kok,
Maria Vittoria Dieci,
Stefan Michiels,
Sandra Demaria,
Sherene Loi,
Abstract
The advent of immune-checkpoint inhibitors (ICI) in modern oncology has significantly improved survival in several cancer settings. A subgroup of women with breast cancer (BC) has immunogenic infiltration of lymphocytes with expression of programmed death-ligand 1 (PD-L1). These patients may potentially benefit from ICI targeting the programmed death 1 (PD-1)/PD-L1 signaling axis. The use of tumor-infiltrating lymphocytes (TILs) as predictive and prognostic biomarkers has been under intense examination. Emerging data suggest that TILs are associated with response to both cytotoxic treatments and immunotherapy, particularly for patients with triple-negative BC. In this review from The International Immuno-Oncology Biomarker Working Group, we discuss (a) the biological understanding of TILs, (b) their analytical and clinical validity and efforts toward the clinical utility in BC, and (c) the current status of PD-L1 and TIL testing across different continents, including experiences from low-to-middle-income countries, incorporating also the view of a patient advocate. This information will help set the stage for future approaches to optimize the understanding and clinical utilization of TIL analysis in patients with BC.