Wenbo Zhou, Huiyan Wang, Yuqi Yang, Fang Guo, Bin Yu, and Zhaoliang Su. Mol. Cells 2022;45:317-28. https://doi.org/10.14348/molcells.2021.0211

Mutations in KRAS, BRAF and PIK3CA are the most common somatic alterations found in the colorectal cancer (CRC) patients from Western countries; but their prevalence and prognostic value have not been adequately assessed in Asian patients. The aim of this study was to determine the mutation frequencies of these genes in Chinese CRC patients and to investigate their impact on prognosis. The sequences of exon 2 of KRAS, exon 15 of BRAF and exons 9 and 20 of PIK3CA were evaluated by PCR and direct sequencing using DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues from primary CRC tumors of 214 patients (colon/rectum: 126/88). KRAS, BRAF and PIK3CA mutations were identified in 44.9% (96/214), 4.2% (9/214) and 12.3% (26/212) CRCs, respectively. The most frequent mutations in KRAS, BRAF and PIK3CA were G12D, V600E and H1047R, respectively. All BRAF and 80.8% PIK3CA mutations were from colon cancer patients. BRAF V600E was associated with advanced TNM (P < 0.001), more distant metastases (P = 0.025), and worse overall survival (OS, P < 0.001; multivariate HR = 4.2, P = 0.004) in colon cancer patients. Compared with KRAS wt/BRAF wt CRC patients (N = 109), those with KRAS codon 13 mutations (N = 25) had significantly worse OS (P = 0.016; multivariate HR = 2.7, P = 0.011), whereas KRAS codon 12-mutated cases were not significantly associated with survival. Among the three most common KRAS mutations, G13D (N = 23) showed significant association with poor OS (P = 0.024; multivariate HR = 2.6, P = 0.016) compared with KRAS wt/BRAF wt patients. Our findings indicate that PI3K/RAS-RAF signaling pathway genes are frequently mutated in Chinese CRC patients, but have different characteristics than found in Western patients. BRAF V600E is an independent prognostic factor for Chinese patients. Our finding that KRAS codon 13 mutations (in particular G13D) are associated with inferior survival in BRAF wild-type CRCs in Chinese patients was not reported thus far. Our data emphasizes the importance of prospective evaluation of molecular features in CRC patients, because a single mutation type may represent a distinct biologic effect and clinical implication.

Background. The association between tumour-infiltrating immune cells and the prognosis of endometrial cancer (EC) is controversial due to the smaller sample sizes and limited statistical power of the extant studies. We carried out a meta-analysis of the relationship between tumour-infiltrating immune cells and EC survival outcomes. Methods. A literature search in multiple databases was carried out up to December 2019. Pooled hazard ratio (HRs) and 95% confidence intervals (CIs) were calculated by the Z-test to assess the association between infiltrating immune cells and overall survival (OS), progression-free survival (PFS), relapse-free survival (RFS), disease-specific survival (DSS), and disease-free survival (DFS). A subgroup analysis was performed based on the localisation of immune cells in tumour parenchyma or stroma, immune markers, and the International Federation of Gynecology and Obstetrics stage. Heterogeneity and publication bias between studies were evaluated by Cochran’s Q-test and Egger regression test, respectively. Results. Seventeen studies were included in the analysis. The pooled HR of OS, PFS, DSS, and DFS indicated that a high CD8⁺ T cell density was associated with a favorable prognosis in EC patients. A significant relationship was found between a high density of CD45RO⁺ T cells and a favorable OS in EC patients, but the FoxP3⁺ T cell density was not associated with either OS or RFS. A high TAM density was associated with a worse PFS. However, a sensitivity analysis indicated that the findings of PFS and DSS in CD8⁺ T cell and PFS in TAM were not robust results. Conclusion. This is the first meta-analysis of the relationship between tumour-infiltrating immune cells and the prognosis of EC. High CD8⁺ and CD45RO⁺ T cell densities in tumours were associated with favorable outcomes in EC patients.