p.G12C KRAS mutation prevalence in non-small cell lung cancer: Contribution from interregional variability and population substructures among Hispanics

Background: The KRAS exon 2 p. G12C mutation in patients with lung adenocarcinoma has been increasing in relevance due to the development and effectiveness of new treatment medications. Studies around different populations indicate that regional variability between ethnic groups and ancestries could play an essential role in developing this molecular alteration within lung cancer. Methods: In a prospective and retrospective cohort study on samples from lung adenocarcinoma from 1000 patients from different administrative regions in Colombia were tested for the KRAS p.G12C mutation. An analysis of STR populations markers was conducted to identify substructure contributions to mutation prevalence. Results: Included were 979 patients with a national mean frequency for the KRAS exon 2 p.G12C mutation of 7.97% (95%CI 6.27–9.66%). Variation between regions was also identified with Antioquia reaching a positivity value of 12.7% (95%CI 9.1–16.3%) in contrast to other regions such as Bogota DC (Capital region) with 5.4% (2.7–8.2%) and Bolivar with 2.4% (95%CI 0–7.2%) (p-value = 0.00262). Furthermore, Short tandem repeat population substructures were found for eight markers that strongly yielded association with KRAS exon 2 p.G12C frequency reaching an adjusted R2 of 0.945 and a p-value of < 0.0001. Conclusions: Widespread identification of KRAS exon 2 p.G12C mutations, especially in cases where NGS is not easily achieved is feasible at a population based level that can characterize regional and national patterns of mutation status. Furthermore, this type of mutation prevalence follows a population substructure pattern that can be easily determined by population and ancestral markers such as STR

Characteristics and outcomes of thymomas in Latin America: results from over 10 years of experience (CLICaP-LATimus)

Background: Thymomas are a group of rare neoplasms of the anterior mediastinum.The objective of this study was to describe the demographics, clinical characteristicsand treatment approaches in Latin America.Methods: This was a retrospective multicenter cohort study including patients withhistologically proven thymomas diagnosed between 1997 and 2018. Demographics, linicopathological characteristics and therapeutic outcomes were collected locallyand analyzed in a centralized manner.Results: A total of 135 patients were included. Median age at diagnos is was 53 yearsold (19–84), 53.3% (n = 72) of patients were female and 87.4% had an ECOG perfor-mance score ranging from 0–1. A total of 47 patients (34.8%) had metastatic diseaseat diagnosis. Concurrent myasthenia gravis occurred in 21.5% of patients. Surgerywas performed in 74 patients (54.8%), comprising 27 (20%) tumorectomies and47 (34.8%) thymectomies. According to the Masaoka-Koga system, overall survival(OS) at five-years was 73.4%, 63.8% and 51%, at stages I–II, III–IVA and IVB,respectively (p = 0.005). Furthermore, patients with low lactate dehydrogenase(LDH) (≤373 IU/L) at baseline and myasthenia gravis concur rence showed signifi-cantly better OS (p = 0.001 and p = 0.008, respectively). In multivariate analysis, highLDH levels (HR 2.8 [95% confidence interval [CI]: 1.1–7.8]; p = 0.036) at baselineand not performing a surgical resection (HR 4.1 [95% CI: 1.3–12.7]; p = 0.016) weresignificantly associated with increased risk of death.Conclusions: Our data provides the largest insight into the clinical characteristics andoutcomes of patients with thymomas in Latin America. Survival in patients withthymomas continues to be very favorable, especially when subjected to adequatelocal control

Human papillomavirus infection and lung adenocarcinoma: special benefit is observed in patients treated with immune checkpoint inhibitors

Human papilloma virus (HPV) has been associated with the development and modulation of response in a series of neoplasms. In the case of lung adenocarcinoma, its role in etiology and pathogenesis is still controversial. Considering that this infection brings foreign epitopes, it could be of prognostic significance in patients with lung adenocarcinoma treated with immunotherapy