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Marques A, Cavaco P, Torre C, Sepodes B, Rocha J. Tumor mutational burden in colorectal cancer: Implications for treatment. Crit Rev Oncol Hematol 2024; 197:104342. [PMID: 38614266 DOI: 10.1016/j.critrevonc.2024.104342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/27/2024] [Accepted: 03/29/2024] [Indexed: 04/15/2024] Open
Abstract
Although immune checkpoint inhibitors have revolutionized the treatment of several advanced solid cancers, in colorectal cancer, the transformative benefit of these innovative medicines is currently limited to those with deficient mismatch repair or high microsatellite instability. Tumor mutational burden (TMB) has emerged as a potential predictor of immunotherapy benefit, but the lack of standardization in its assessment and reporting has hindered the introduction of this biomarker in routine clinical practice. Here, we compiled 45 colorectal cancer studies utilizing numerical thresholds for high-TMB. In this group of studies, TMB cut-offs ranged from 6.88 to 41 mut/Mb and were most often set at 10, 17, or 20 mut/Mb. Additionally, we observed divergent TMB definitions and inconsistent disclosure of specific methodological details, which collectively emphasize the substantial lack of harmonization within the field. Ongoing efforts to harmonize TMB assessment will be critical to validate TMB as a predictive marker of immunotherapy response.
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Affiliation(s)
- Adriana Marques
- Research Institute for Medicines (iMed.ULisboa), Lisboa 1649-003, Portugal; Faculdade de Farmácia, Universidade de Lisboa, Lisboa 1649-003, Portugal
| | - Patrícia Cavaco
- Research Institute for Medicines (iMed.ULisboa), Lisboa 1649-003, Portugal; Faculdade de Farmácia, Universidade de Lisboa, Lisboa 1649-003, Portugal; Pharmacy Department, Centro Hospitalar de Lisboa Ocidental, Lisboa 1449-005, Portugal
| | - Carla Torre
- Research Institute for Medicines (iMed.ULisboa), Lisboa 1649-003, Portugal; Faculdade de Farmácia, Universidade de Lisboa, Lisboa 1649-003, Portugal
| | - Bruno Sepodes
- Research Institute for Medicines (iMed.ULisboa), Lisboa 1649-003, Portugal; Faculdade de Farmácia, Universidade de Lisboa, Lisboa 1649-003, Portugal
| | - João Rocha
- Research Institute for Medicines (iMed.ULisboa), Lisboa 1649-003, Portugal; Faculdade de Farmácia, Universidade de Lisboa, Lisboa 1649-003, Portugal.
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Yang L, Liu S, He W, Xiong Z, Xia L. Characterisation of tumor microenvironment and prevalence of CD274/PD-L1 genetic alterations difference in colorectal Cancer. BMC Cancer 2023; 23:221. [PMID: 36894899 PMCID: PMC9996909 DOI: 10.1186/s12885-023-10610-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 02/06/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Large-scale genomic alterations, especially CD274/PD-L1 gene amplification, have great impact on anti-PD-1 efficacy on cancers such as Hodgkin's lymphoma. However, the prevalence of PD-L1 genetic alterations in colorectal cancer (CRC) and its correlation with the tumor immune microenvironment and clinical implications remain unknown. MATERIALS AND METHODS PD-L1 genetic alterations were evaluated in 324 patients with newly diagnosed CRC including 160 mismatch repair-deficient (dMMR) patients and 164 mismatch repair-proficient (pMMR) patients using fluorescence in situ hybridization (FISH) method. The correlation between PD-L1 and the expression of the common immune markers was analyzed. RESULTS Totally 33 (10.2%) patients were identified with aberrant PD-L1 genetic alternations including deletion (2.2%), polysomy (4.9%), and amplification (3.1%); They had more aggressive features such as advanced stage (P = 0.02), shorter overall survival (OS) (P < 0.001) than patients with disomy. The aberrations correlated with positive lymph node (PLN) (p = 0.001), PD-L1 expression by immunohistochemistry (IHC) in tumor cells (TCs) or tumor-infiltrated immunocytes (ICs) (both p < 0.001), and pMMR (p = 0.029). When dMMR and pMMR were analyzed independently, the correlations of aberrant PD-L1 genetic alterations with PD-1 expression (p = 0.016), CD4 + T cells (p = 0.032), CD8 T + cells (p = 0.032) and CD68 + cells (p = 0.04) were only found in dMMR cohort. CONCLUSIONS The prevalence of PD-L1 genetic alterations was relatively low in CRC, but the aberrations usually correlate with aggressive nature. The correlation between PD-L1 genetic alterations and tumor immune features was only observed in dMMR CRC.
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Affiliation(s)
- Lin Yang
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, 1838 Baiyun Avenue North, Guangzhou, 510515, China
| | - Shousheng Liu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Centre for Cancer Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China.,Department of General Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China
| | - Wenzhuo He
- State Key Laboratory of Oncology in South China, Collaborative Innovation Centre for Cancer Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China.,Department of General Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China
| | - Zhenchong Xiong
- State Key Laboratory of Oncology in South China, Collaborative Innovation Centre for Cancer Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China. .,Department of Breast Oncology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China.
| | - Liangping Xia
- State Key Laboratory of Oncology in South China, Collaborative Innovation Centre for Cancer Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China. .,Department of General Medicine, Sun Yat-sen University Cancer Center, 651 Dongfeng Road east, Guangzhou, 510060, China.
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