Molecular Signatures of KRAS-Mutated Lung Adenocarcinoma: Analysis of Concomitant EGFR, ALK, STK11, and PD-L1 Status

Comprehensive genomic profiling reveals a unique genomic landscape in solid tumors in an Indian cancer cohort of 1000 patients: a single institutional experience

The use of Comprehensive Genomic Profiling (CGP) in clinical practice to detect broad-spectrum therapeutic, prognostic, and predictive biomarkers, including tumor mutational burden (TMB), microsatellite instability (MSI), somatic BRCA (sBRCA) and other homologous recombination repair genes (HRRs) provides a more cost-efficient and tissue-preserving approach than serial single-biomarker analysis. A total of 1000 biopsy-proven cancer patients at the HCG cancer center were profiled in an IRB-approved prospective study. The findings were discussed in the multidisciplinary molecular tumor board (MTB), and recommendations were documented in electronic medical records (EMRs) for clinical management and follow-up. A total of 1747 genomic alterations were detected (mean 1.7 mutations/sample), with 80% of patients having genetic alterations with therapeutic and prognostic implications (Tier I-32%, Tier II-50%). CGP revealed a greater number of druggable genes (47%) than did small panels (14%). Tumor-agnostic markers for immunotherapy (IO) were observed in 16% of the current cohort, based on which IO was initiated. In 13.5% of the cohort, alterations in the HRR pathway including sBRCA (5.5%) were detected providing an option for treatment with platinum or PARP inhibitors. Other significant alterations included those in EGFR, KRAS/BRAF, PIK3CA, cKIT, PDGFRA, ARID1A, ARID2, and FGFR. RNA sequencing revealed 55 + RNA alterations, including those in TMPRSS-ERG, RPS6KB1-VMP1, EML4-ALK, NTRK, PDGFRA and EWSR. Clinical outcome data were available via EMR for 618 patients (62%), out of whom 419 patients had druggable mutations (67%; 95% CI 88.9-93.9%) and 39 patients had 1 or more mutations with prognostic implications. However, only 200 patients (44%; 95% CI 39.1-48.1%) were included in the MTB discussion. Based on genomics reports, the treatment regimen was changed for 137 and 61 patients with and without clinical inputs from the MTB, respectively. The overall change in therapy based on CGP in the clinical cohort was 43%, which was greater in patients enrolled for MTB than in patients who had not undergone MTB. At the interim analysis, with a median follow-up of 18 months (range 12-24 months) after the change in therapy as per genomics report, 97 patients (71%) were found to be alive thus establishing the importance of CGP and MTB in personalized genomics-driven treatment.

Activity and resistance to KRASG12C inhibitors in non-small cell lung cancer and colorectal cancer

Non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) are associated with a high mortality rate. Mutations in the V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) proto-oncogene GTPase (KRAS) are frequently observed in these cancers. Owing to its structural attributes, KRAS has traditionally been regarded as an "undruggable" target. However, recent advances have identified a novel mutational regulatory site, KRASG12C switch II, leading to the development of two KRASG12C inhibitors (adagrasib and sotorasib) that are FDA-approved. This groundbreaking discovery has revolutionized our understanding of the KRAS locus and offers treatment options for patients with NSCLC harboring KRAS mutations. Due to the presence of alternative resistance pathways, the use of KRASG12C inhibitors as a standalone treatment for patients with CRC is not considered optimal. However, the combination of KRASG12C inhibitors with other targeted drugs has demonstrated greater efficacy in CRC patients harboring KRAS mutations. Furthermore, NSCLC and CRC patients harboring KRASG12C mutations inevitably develop primary or acquired resistance to drug therapy. By gaining a comprehensive understanding of resistance mechanisms, such as secondary mutations of KRAS, mutations of downstream intermediates, co-mutations with KRAS, receptor tyrosine kinase (RTK) activation, Epithelial-Mesenchymal Transitions (EMTs), and tumor remodeling, the implementation of KRASG12C inhibitor-based combination therapy holds promise as a viable solution. Furthermore, the emergence of protein hydrolysis-targeted chimeras and molecular glue technologies has been facilitated by collaborative efforts in structural science and pharmacology. This paper aims to provide a comprehensive review of the recent advancements in various aspects related to the KRAS gene, including the KRAS signaling pathway, tumor immunity, and immune microenvironment crosstalk, as well as the latest developments in KRASG12C inhibitors and mechanisms of resistance. In addition, this study discusses the strategies used to address drug resistance in light of the crosstalk between these factors. In the coming years, there will likely be advancements in the development of more efficacious pharmaceuticals and targeted therapeutic approaches for treating NSCLC and CRC. Consequently, individuals with KRAS-mutant NSCLC may experience a prolonged response duration and improved treatment outcomes.