Tumor mutational burden (TMB) is a genomic biomarker that predicts favorable responses to immune checkpoint inhibitors (ICIs). Here, we set out to assess the predictive value of TMB on long-term survival outcomes in patients undergoing ICIs. We systematically searched PubMed, Embase, CENTRAL and clinicaltrials.gov from inception to 6 August 2019. We included retrospective studies or clinical trials of ICIs that reported hazard ratios (HRs) for overall survival (OS) and/or progression-free survival (PFS) according to TMB. Data on 5712 patients from 26 studies were included. Among patients who received ICIs, high TMB groups showed better OS (HR 0.53, 95% CI 0.42 to 0.67) and PFS (HR 0.52, 95% CI 0.40 to 0.67) compared to low TMB groups. In patients with high TMB, those who received ICIs had a better OS (HR 0.69, 95% CI 0.50 to 0.95) and PFS (HR = 0.66, 95% CI = 0.47 to 0.92) compared to those who received chemotherapy alone, while in patients with low TMB, such ICI benefits of OS or PFS were not statistically significant. In conclusion, TMB may be an effective biomarker to predict survival in patients undergoing ICI treatment. The role of TMB in identifying patient groups who may benefit from ICIs should be determined in future randomized controlled trials.
Bibliographical noteFunding Information:
Yonsei University College of Medicine, Seoul 03722, Korea; firstname.lastname@example.org Department of Internal Medicine IV, Medical University Innsbruck, 6020 Innsbruck, Austria; email@example.com Luton & Dunstable University Hospital NHS Foundation Trust, Luton LU4 0DZ, UK; firstname.lastname@example.org Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA; email@example.com Department of Medical Oncology, Amsterdam UMC, Cancer Center Amsterdam, VU University, 1081 HV Amsterdam, The Netherlands; firstname.lastname@example.org Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea Department of Pediatrics, Yonsei University College of Medicine, Seoul 03722, Korea Internal Medicine V, Department of Hematology & Oncology, Medical University Innsbruck, 6020 Innsbruck, Austria; email@example.com Tyrolean Cancer Research Institute, 6020 Innsbruck, Austria Correspondence: firstname.lastname@example.org (J.K.); email@example.com (J.I.S.); Tel.: +82-2-2019-3369 (J.K.); +82-2-2228-2050 (J.I.S.)
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.
All Science Journal Classification (ASJC) codes
- Cancer Research