Abstract 323P
Background
Tumor mutation burden (TMB) may predict immune checkpoint inhibitor (ICI) response. TMB calculation included all nonsynonymous somatic mutations, but not all mutations were favorable and the efficient of TMB is attenuated by including adverse mutations. Moreover, no universal cutoff value of high TMB hindered its application in practice.
Methods
Tumor mutation score (TMS), defined as number of genes with nonsynonymous somatic mutations, was compared with TMB in 10,336 cancer patients from MSK-IMPACT cohort. TMS55, TMS of 55 favorable prognosis genes and TMB were calculated and compared in 1,661 advanced cancer patients treated with ICI and 3,840 matching non-ICI patients of ten major cancer types.
Results
TMS55 was significantly associated with TMB. In 1,661 ICI patients, high TMS55 (TMS55>5) was more robust than high TMB (highest 20% in each histology) in predicting better overall survival. Separately, TMS55 was significantly associated with improved survival in more tumor types than TMB with smaller hazard ratio values, especially in non-small cell lung cancer, melanoma, bladder cancer and colorectal cancer. Conversely, high TMS55 and TMB predicted worse overall survival in 3,840 non-ICI patients.
Conclusions
Novel TMS55 might be better than TMB as biomarker for patients treated with ICI and customized TMS might substitute non-selective TMB as mutation-based biomarker. Easy calculation and universal cutoff value of TMS will not be affected across platforms and is more feasible in clinical, which may greatly promote its application in clinical with further validations.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4P - Impact of chemotherapy and radiotherapy on tissue expander or implant removal in breast cancer patients
Presenter: Sungmi Jung
Session: Poster display session
Resources:
Abstract
5P - Long-term prognostic effect of hormone receptor subtype on breast cancer
Presenter: Ki-tae Hwang
Session: Poster display session
Resources:
Abstract
6P - Effect of apparent diffusion coefficient in predicting pathologic responses in patients with breast cancer treated with neoadjuvant chemotherapy using nanoparticle albumin-bound paclitaxel
Presenter: Yutaka Mizuno
Session: Poster display session
Resources:
Abstract
7P - Current diagnostic strategy for mammographic microcalcification without specific ultrasound abnormality
Presenter: Naoki Sato
Session: Poster display session
Resources:
Abstract
8P - Comparison of standard uptake value of 18F-FDG-PET-CT with tumour-infiltrating lymphocytes in breast cancer ≥1cm
Presenter: Soeun Park
Session: Poster display session
Resources:
Abstract
10P - Prognosis and effect of adjuvant treatment in small, node(-), HER2(+) breast cancer
Presenter: Seungtaek Lim
Session: Poster display session
Resources:
Abstract
11P - The prognosis of rare histopathologic subtype of breast cancer
Presenter: Soo Youn Bae
Session: Poster display session
Resources:
Abstract
12P - Daily collection of physical activity via smartphone application and smart band for development of distress screening tools in breast cancer survivors: A feasibility study
Presenter: Yungil Shin
Session: Poster display session
Resources:
Abstract
13P - Breast cancer distribution in East Azerbaijan, Iran: Results of population-based cancer registry
Presenter: Shima Pashaei
Session: Poster display session
Resources:
Abstract
14P - Validation of the optimum timing of assessment of tumour infiltrating lymphocytes during preoperative chemotherapy for breast cancer
Presenter: Shinichiro Kashiwagi
Session: Poster display session
Resources:
Abstract