Bladder cancer (BC) is highly immunogenic. Bacillus Calmette-Guérin (BCG) immunotherapy offers the best results in non-muscle-invasive BC (NMIBC). Natural killer cells (NKcs) play decisive roles in BCG-mediated immune response and in general cancer immune-surveillance.
To analyze killer-cell immunoglobulin-like receptors (KIRs), their human leukocyte antigen class-I (HLA-I) ligands, and the expression of DNAX Accessory Molecule-1 (DNAM-1/CD226) on peripheral blood (PB) NKcs, to identify useful predictive biomarkers in BC.
KIR/HLA-ligand genotypes were compared between 132 BC, 201 other solid cancers, 164 plasma cell disorders, and 615 healthy Caucasoid controls. CD226 expression was evaluated by flow cytometry.
KIR/HLA-I interactions and CD226 expression on NKcs (CD226high or CD226low) were compared across study groups, cancer stages, treatments, and progression-free and overall survival of patients, using chi-square, analysis of variance/post hoc, Kaplan-Meier/log-rank, and regression analyses.
Three immunological risk groups were identified: low risk (KIR2DL1-L2+L3-/C1C1- and KIR2DL1+L2+L3+/C1C1+), intermediate risk (rest), and high risk (KIR2DL5+/HLA-C*16+ and KIR2DL1+L2+L3-), which displayed different 10-yr progression-free rates (83.3%, 48.6%, and 0%, respectively; p<0.001) and survival rates (83.3%, 54.3%, and 6.2%, respectively; p<0.001) for muscle-invasive T2/T4, and 10-yr progression-free rates (100%, 81.6%, and 50%, respectively; p<0.05) for NMIBC-T1 treated with BCG. Immunological risk stratification had an independent prognostic value to just histological staging for survival (hazard ratio=2.93, p<0.00001, Harrell C-statistic=0.779). CD226 expression on PB NKcs improved immunological stratification in intermediate-risk T1-T4 BC patients, with survival rates of 94.1% and 66.7% for CD226high and CD226low (p<0.05), respectively.
Immunological risk stratification will complement BC histopathology to improve risk stratification and guide the selection of personalized treatments. Understanding of the molecular mechanisms of NKc tumor immune surveillance will enable the development of future NKc-based therapies.
This work describes a peripheral blood test that aids in our understanding of the immune defense mechanisms against bladder cancer, is useful for classifying patient risk, and will guide personalized treatments.
European urology oncology. 2019 May 14 [Epub ahead of print]
Concepción F Guillamón, Lourdes Gimeno, Gerardo Server, María V Martínez-Sánchez, José F Escudero, Pedro López-Cubillana, Juan Cabezas-Herrera, José A Campillo, Daniel J Abellan, Jerónimo Martínez-García, Jorge Martínez-Escribano, Belén Ferri, María R López-Álvarez, Cristóbal Moreno-Alarcón, María R Moya-Quiles, Manuel Muro, Alfredo Minguela
Immunology Service, Hospital Clínico Universitario Virgen de la Arrixaca (HCUVA) Instituto Murciano de Investigación Biosanitaria (IMIB), Murcia, Spain., Urology, HCUVA-IMIB, Murcia, Spain., Molecular Therapy and Biomarkers Research Group, Clinical Analysis Service, HCUVA-IMIB, Murcia, Spain., Dermatology Services, HCUVA-IMIB, Murcia, Spain., Pathology Services, HCUVA-IMIB, Murcia, Spain., Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK., Immunology Service, Hospital Clínico Universitario Virgen de la Arrixaca (HCUVA) Instituto Murciano de Investigación Biosanitaria (IMIB), Murcia, Spain. Electronic address: .