PIK3CA

This study investigates predictive biomarkers for immune checkpoint inhibitor (ICI) response in metastatic urothelial carcinoma. Researchers found that ICI responders exhibited higher tumor mutational burden (TMB) and enriched mutations in genes such as PIK3CA. Functional in vitro and in vivo studies demonstrated that PIK3CA mutations enhance tumor immunogenicity by activating the IRF1-NLRC5-MHC-I axis, thereby improving antigen presentation and CD8+ T-cell cytotoxic response. These findings suggest that PIK3CA mutation could serve as a biomarker to predict ICI sensitivity and represents a novel immune-modulating mechanism.

This retrospective study investigated the clinical, surgical, and molecular characteristics and outcomes of 52 adult patients with H3 K27-altered diffuse midline glioma (DMG) treated with surgical resection. The median overall survival was 17.8 months. Genomic profiling revealed a distinct molecular landscape dominated by H3F3A mutations, frequently co-occurring with TP53 mutations, and a significant enrichment of mutations within the RTK/RAS/PI3K signaling pathway, involving NF1, FGFR1, and PIK3CA. Postoperative adjuvant radiotherapy combined with temozolomide emerged as the sole independent protective factor for overall survival. While maximal safe resection is considered essential, molecular targeted therapies did not achieve independent statistical significance.

This prospective observational study assessed the utility of circulating tumor DNA (ctDNA) for mutational profiling and dynamic monitoring in 33 patients with metastatic colorectal cancer receiving palliative chemotherapy. ctDNA was detected in most patients at baseline, revealing frequent mutations in APC, TP53, KRAS, and PIK3CA. Good concordance was observed between plasma ctDNA profiles and tissue data. Longitudinal analysis showed the emergence of acquired mutations, particularly RAS mutations under anti-EGFR therapy, and correlated high ctDNA levels with shorter overall survival. These findings highlight ctDNA's potential to guide personalized treatment strategies and monitor resistance.

This prospective study evaluated gene expression profiling of seven genes (EGFR, FGFR2, PIK3CA, PTEN, SMAD4, STK11, TP53) in cell-free RNA (cfRNA) from exhaled breath condensate (EBC) in patients with advanced lung adenocarcinoma. Results indicated that PIK3CA showed the best diagnostic performance in distinguishing patients from healthy controls. High expression of FGFR2 and PIK3CA was associated with significantly shorter overall survival, highlighting their prognostic relevance. EGFR expression demonstrated a strong correlation between EBC and plasma, and low EGFR expression was linked to longer survival in patients receiving chemotherapy alone. This non-invasive EBC-based approach offers potential for molecular characterization and patient stratification.

This review examines established and emerging biomarkers for stratifying patients with early-stage breast cancer to optimize adjuvant systemic therapy. It highlights that while clinicopathological factors remain fundamental, decision-making is increasingly driven by precise biological markers. ER and HER2 status are crucial, and multigene assays refine recurrence risk and chemotherapy benefit in hormone receptor-positive cancers. Immune and DNA-repair biomarkers inform targeted therapies in HER2-positive and triple-negative subtypes, while mutation profiling of genes like ESR1, PIK3CA, AKT, MTOR, and PTEN guides targeted treatments. Emerging approaches, including liquid biopsy and artificial intelligence, offer dynamic insights but require prospective validation.

This study analyzed the genomic profile of 480 patients with metastatic adenocarcinoma of unknown primary (ACUP) using the FoundationOne CDx platform. The most frequent mutations included TP53, KRAS, and CDKN2A. Results showed that GNAS and PIK3CA mutations were associated with better overall survival. Conversely, ARID1A and NOTCH1 alterations were linked to a worse prognosis. These findings highlight the significance of specific genomic alterations as prognostic markers in ACUP.

This meta-analysis investigated the efficacy of rechallenging with CDK4/6 inhibitors (CDK4/6i) after progression in patients with HR-positive, HER2-negative advanced/metastatic breast cancer. The study included 1396 patients from eight clinical trials, comparing CDK4/6i rechallenge plus endocrine therapy to endocrine therapy alone. Results indicated a significant improvement in median progression-free survival (PFS) of 5.8 months versus 3.7 months. A greater benefit was observed when switching to a different CDK4/6 inhibitor, particularly with abemaciclib, but no overall survival benefit was demonstrated.