Background: Understanding PIK3CA mutations and co-mutations in non-small cell lung carcinoma (NSCLC) is critical to developing personalized treatment strategies. Therefore, this study aims to investigate PIK3CA mutations and the accompanying somatic variations in NSCLC. Methods: This retrospective study included 98 patients over 18 years of age who were diagnosed with NSCLC, operated on, and referred to the Molecular Pathology Laboratory between January 2019 and June 2024 for next-generation sequencing panel tests and ALK-ROS1 FISH analysis. Results: All patients were found to carry PIK3CA mutations. Among the 98 NSCLC patients analyzed, 16 (16.33%) were female and 82 (83.67%) were male. The average age of the patients was 64.53 ± 9.63 years, with an age range of 38–84 years, and the majority were 50 years or older. Of the cases, 51 presented the adenocarcinoma subtype, while the remaining 47 showed the squamous cell carcinoma subtype. A smoking history was present in 77 (78.57%) patients, while 21 (21.43%) had no smoking history. The most frequently detected pathogenic or likely pathogenic PIK3CA variations were c.1633G>A p.E545K (32.65%), c.1624G>A p.E542K (11.22%), c.3140A>G p.H1047R (11.22%), c.3140A>T p.H1047L (5.10%), c.1357G>C p.E453Q (4.08%), and c.3143A>G p.H1048R (2.04%). The top 10 mutations that most commonly accompanied PIK3CA variations were KRAS, NF1, TP53, EGFR, PTEN, BRAF, KIT, CDKN2A, SMARCA4, and ATM mutations, respectively. Conclusions: PIK3CA variations, along with other gene variations, may influence cancer progression and thus may play a crucial role in the determination of targeted treatment strategies.

Lung cancer is the most common cancer type worldwide, with non-small cell lung cancer being the most frequently studied. Identifying of cancer-related genes in non-small cell lung cancer is crucial for developing individualized treatment, particularly as mutation profiles can vary by country and ethnicity. To identify comprehensive mutation profiles in a cohort of Turkish patients with non-small cell lung cancer using the next-generation sequencing. Retrospective cross-sectional study. In total, 72 cancer-related genes and 4149 variants were recorded in the non-small cell lung cancer panel, and their relationship with clinical and histopathological features was investigated through next-generation sequencing. Among 507 patients, 420 (82.8%) were males and 87 (17.2%) were females. Percentages of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (11%), B-Raf proto-oncogene, serine/threonine kinase (8%), and neurofibromatosis type 1 (6%) mutations were higher than those reported in the literature. Males had a higher rate of Kirsten rat sarcoma 2 viral oncogene homolog mutations (P = .102), whereas epidermal growth factor receptor mutations were statistically more common in females (P = .001). Multiple variants of strong significance were identified in 6.3% patients diagnosed with adenocarcinoma, most of whom were smokers. Kirsten rat sarcoma 2 viral oncogene homolog and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha mutations were most commonly observed. This study shows that Turkish patients have higher rates of PIK3CA, BRAF and NF1 mutations compared to the literature. Studies to determine the molecular profile specific to Turkish people will guide clinicians in treatment and contribute significantly to determining priorities in diagnosis.

Introduction: Absence of mismatch repair (MMR) genes in tumor cells or errors in the replication repair process may lead to DNA-MMR deficiency and microsatellite instability (MSI) formation. Specific tumor environments where gene variations are observed are believed to be conducive to the formation of MSI. This study aimed to determine the MSI status, MMR protein expression, and somatic mutation profile in solid organ tumors.Material and methods: In this study, the records of 192 patients with solid organ tumors who were referred to the Molecular Pathology Laboratory between January 2018 and December 2022 were reviewed retrospectively. The MSI profiles of the patients were evaluated using real-time polymerase chain reaction (PCR) and immunohistochemical (IHC) methods. Somatic variations in the patients were detected using an NGS colon cancer panel.Results: In the IHC evaluation, 22 cases showed MMR-deficient (dMMR) or high MSI (MSI-H), and 170 cases showed MMR-proficient (pMMR) or microsatellite stable (MSS). Real-time PCR results on the 22 dMMR cases revealed that 11 cases had MSI-H and 11 cases had MSS status. Among the 170 cases with pMMR, 160 cases were found to have MSS status, while 10 cases had low MSI (MSI-L). NGS analysis revealed that the three most frequent pathogenic variants in all cases were BLM exon 7 c.1544delA, MSH3 exon 7 c.1148delA, and MLH3 exon 2 c.1755delA. MSI-H cancer patients had a higher variation burden compared to MSS cancer patients. The most frequently observed pathogenic variant in both MSI-H and MSS cancer patients was BLM exon 7 c.1544delA.Conclusions: Our study covers not only colorectal cancer patients but also other solid tumor types, providing the first data from the Turkish population on the MSI-H/dMMR status and somatic mutation profile in the presence of this condition.

Background/Aims: Recent studies that reveal the molecular profiles of colorectal carcinomas have demonstrated tumor heterogeneity. Characterization of colorectal carcinoma-specific genomic alterations is essential for developing more successful and targeted treat- ment protocols. Moreover, it is vital in elucidating the pathogenesis and mechanisms of resistance against treatment and predicting prognosis. Materials and Methods: The study included 73 cases diagnosed with colorectal carcinomas and subjected to molecular analysis by the next-generation sequencing. The association between the clinicopathologic parameters and pathogenic mutations detected in 32 genes was evaluated. Results: Pathogenic mutations were determined in a total of 24 genes. The Cell Division Cycle 27 (CDC27), Kirsten rat sarcoma viral proto-oncogene (KRAS), serine/threonine protein kinase B-raf (BRAF), phosphatase and tensin homolog, breast cancer 2 (BRCA2), and phosphotidylinositol-4,5-biphosphate 3-kinase (PIK3CA) mutations were determined at higher rates, with the adenomatous polypo- sis coli mutation determined at a lower rate than in the literature. There were significant positive correlations between CDC27 and phosphatase and tensin homolog (PTEN), PTEN and BRCA2, and PTEN and adenomatous polyposis coli (APC) concomitant muta- tions, whereas negative correlations were present between BRAF and KRAS. Statistically significant relationships were present between KRAS exon 2 and mucinous morphology, PIK3CA and absence of perineural invasion, BRAF and tumor differentiation/localization, MutS homolog 3 (MSH3) and tumor diameter, and BRCA2 and absence of lymph node metastasis. Conclusion: It is necessary to have a comprehensive database of genomic alterations of colorectal carcinomas to interpret mutations more accurately clinically. There are no studies on the frequency of mutations in colorectal carcinomas in the Turkish population; thus, follow-up and treatment protocols are organized following the European and American databases and guidelines. A comprehensive study of the colorectal carcinoma patients’ mutation profile in the Turkish patient cohort by the next-generation sequencing method will help to provide significant therapeutic, prognostic, and predictive data and design more successful treatment and follow-up strategies.

Turkish Journal of Geriatrics is the official publication of Turkish Geriatrics Society and is published four times a year. Turkish Journal of Geriatrics is a peer-reviewed journal and is devoted to high standards of scientific rules and publication ethics.