Retrospective cohort study of tumor-infiltrating clonal hematopoiesis and pan-cancer prognosis in patients with solid tumors

Tumor-infiltrating clonal hematopoiesis (TI-CH) indicates the infiltration of somatically mutated hematopoietic cells into the tumor environment. The clinical relevance of TI-CH in solid tumors is poorly understood. A retrospective cohort study analyzed whole-genome sequencing data of patients with solid tumors from the Genomics England 100 000 Genomes Project between 2015 and 2019. The primary outcome was the prevalence of TI-CH, defined by somatic variants in 74 driver genes (VAF 2% to 30%) in tumor tissue. Among 10 571 patients with solid tumors (mean age 64.68 ± 12.18 years; 60.83% female), TI-CH was detected in 1943 patients (18.38%) with the highest frequency observed in patients with TET2 variants (10.91%) and in patients with endometrial cancer (32%). Older age and prior cytotoxic chemotherapy were significantly associated with an increased likelihood of TI-CH; furthermore, there was as significant association between TI-CH and worse overall survival, particularly in patients with breast cancer. The authors conclude that these findings suggest that TI-CH may serve as a prognostic biomarker in solid tumors.