KRAS, NRAS and BRAF Mutational Profile of Colorectal Cancer in a Series of Moroccan Patients.

OBJECTIVES: The present study aimed to evaluate the frequencies of KRAS, NRAS, and BRAF mutations and their possible associations with clinicopathological features in 249 Moroccan patients with colorectal cancer (CRC). METHODS: A retrospective investigation of a cohort of formalin-fixed paraffin-embedded tissues of 249 patients with CRC was screened for KRAS/NRAS/BRAF mutations using Idylla™ technology and pyrosequencing. RESULTS: KRAS, NRAS, and BRAF mutations were revealed in 46.6% (116/249), 5.6% (14/249), and 2.4% (6/249) of patients. KRAS exon 2 mutations were identified in 87.9% of patients (102/116). KRAS G12D and G12 C were the most frequent, at 32.8% and 12.93%, respectively. Among the patients with KRAS exon 2 wild-type (wt), 27.6% (32/116) harbored additional KRAS mutations. Concurrent KRAS mutations were identified in 9.5% (11/116); including six in codon 146 (A146P/T/V), three in codon 61 (Q61H/L/R), one in codon 12 (G12 A and Q61H), and one in codon 13 (G13D and Q61 L). Among the NRAS exon 2 wt patients, 64.3% (9/14) harbored additional NRAS mutations. Concurrent NRAS mutations were identified in 28.6% (4/14) of NRAS-mutant patients. Since 3.2% wt KRAS were identified with NRAS mutations, concomitant KRAS and NRAS mutations were identified in 2.4% (6/249) of patients. KRAS mutations were higher in the >50-year-old age-group (P = .031), and the tumor location was revealed to be significantly associated with KRAS mutations (P = .028) predominantly in left colon (27.5%) and colon (42.2%) locations. NRAS mutations were most prevalent in the left colon (42.8%) and in well-differentiated tumors (64.2%). CONCLUSION: Detection of KRAS mutations, particularly the G12 C subtype, may be significant for patients with CRC and has possible therapeutic implications. However, rare KRAS concomitant mutations in CRC patients suggest that each individual may present distinct therapeutic responses. KRAS testing alongside the identification of other affected genes in the same patient will make the treatments even more personalized by contributing more accurately to the clinical decision process. Overall, early diagnosis using novel molecular techniques may improve the management of CRC by providing the most efficient therapies for Moroccan patients.

Prevalence and patterns of mutations in RAS/RAF/MEK/ERK/MAPK signaling pathway in colorectal cancer in North Africa.

BACKGROUND: Our review discuss (i) the findings from analyzed data that have examined KRAS, NRAS and BRAF mutations in patients with colorectal cancer (CRC) in North Africa and to compare its prevalence with that shown in other populations and (ii) the possible role of dietary and lifestyle factors with CRC risk.  METHODS: Using electronic databases, a systematic literature search was performed for the KRAS, NRAS, and BRAF mutations in CRC patients from Morocco, Tunisia, Algeria and Lybia.  RESULTS: Seventeen studies were identified through electronic searches with six studies conducted in Morocco, eight in Tunisia, two in Algeria, and one in Libya. A total of 1843 CRC patients were included 576 (31.3%) in Morocco, 641 (34.8%) in Tunisia, 592 (32.1%) in Algeria, and 34 (1.8%) in Libya. Overall, the average age of patients was 52.7 years old. Patients were predominantly male (56.6%). The mutation rates of KRAS, NRAS and BRAF were 46.4%, 3.2% and 3.5% of all patients, respectively. A broad range of reported KRAS mutation frequencies have been reported in North Africa countries. The KRAS mutation frequency was 23.9% to 51% in Morocco, 23.1% to 68.2% in Tunisia, 31.4% to 50% in Algeria, and 38.2% in Libya. The G12D was the most frequently identified KRAS exon 2 mutations (31.6%), followed by G12V (25.4%), G13D (15.5%), G12C (10.2%), G12A (6.9%), and G12S (6.4%). G12R, G13V, G13C and G13R are less than 5%. There are important differences among North Africa countries. In Morocco and Tunisia, there is a higher prevalence of G12D mutation in KRAS exon 2 (≈50%). The most frequently mutation type in KRAS exon 3 was Q61L (40%). A59T and Q61E mutations were also found. In KRAS exon 4, the most common mutation was A146T (50%), followed by K117N (33.3%), A146P (8.3%) and A146V (8.3%). CONCLUSION: KRAS mutated CRC patients in North Africa have been identified with incidence closer to the European figures. Beside established anti-CRC treatment, better understanding of the causality of CRC can be established by combining epidemiology and genetic/epigenetic on CRC etiology. This approach may be able to significantly reduce the burden of CRC in North Africa.

Genetic Profiling of Non-Small Cell Lung Cancer in Moroccan Patients by Targeted Next-Generation Sequencing.

OBJECTIVES: We retrospectively analyzed the next-generation sequencing (NGS) results from diagnosed NSCLC patients to identify and compare genomic alterations of NSCLC between Moroccan patients and the Cancer Genome Atlas (TCGA). We also aimed to investigate the distribution and frequency of concurrent genomic alterations. METHODS: From December 2022 to December 2023, a retrospective study of 76 formalin-fixed paraffin-embedded (FFPE) samples have been profiled using the Oncomine™ Precision Assay on the Ion Torrent™ Genexus™ Integrated Sequencer across the panel of 50 key genes that are applicable for the selection of targeted therapy. RESULTS: Seventy of the 76 FFPE sequenced samples carried at least one genetic alteration in the tested genes. The study identified 234 genetic alterations in 18 genes. Targetable genetic alterations in EGFR, KRAS, MET, BRAF, ALK, RET and ROS1 were identified in 84.3% of tumors. EGFR and KRAS mutations were frequently reported, occurring in 24.3% and 22.9% of cases, respectively. The untargetable genetic alterations were found in 74.3% of the specimens in FGFR3, TP53, ERBB2, PIK3CA, CDKN2A, PDL1, FGFR1, PTEN, CHEK2 and ERBB3. There were additional uncommon/rare mutations in EGFR, BRAF, RET and ROS1. Comparing the prevalence of selected mutated genes in the NSCLC patients from the TCGA database identified substantial differences in EGFR (24.3%, vs14.97%), KRAS (22.9%, vs 25.99%), and TP53 (34.3%, vs 50.94%). ALK, ROS1, and RET gene rearrangements were detected in 4.3% of the 70 tumors tested. The ALK/RET/MET/ROS1/EML4 fusions were detected in 11.4% of samples. Co-alterations occurred in 67.1% of specimens. Co-occurring driver gene mutations were observed in 44.3%. TP53 mutations co-occurred driver gene mutations in 30% of tumors. Three cases (4.3%) harbored concurrent FGFR3, TP53, and PIK3CA alterations. CONCLUSION: Our results regarding the proportion of samples with actionable mutations demonstrate the value of NGS testing for NSCLC patients in a real-world clinical diagnostic setting.

Neutralising antibodies against SARS-CoV-2 give important information on Covid-19 epidemic evolution in Rabat, Morocco, March 2020-February 2021.

Background: The SARS-CoV-2 is an extremely contagious and acute viral disease mainly affecting humans. Objective: To estimate seroprevalence of SARS-CoV-2 neutralizing antibodies (NAbs) for illegible armed force individuals living in Rabat, Morocco. Method: A convenience sample (N = 2662) was conducted from May 2020 to February 2021. We used the standard neutralization assay to quantify the NAbs titers. A serum was positive when the titer was 1:4. High positive NAbs titers were defined when ≥ 1:32. Results: Demographic and socioeconomic status did not affect seroprevalence data. An overall seroprevalence of 24,9% was found. Sera from blood donors, young recruits and auto-immune population had lower NAbs titers. However, titers were above 1:16 in 9% of the population with high risk of SARS-CoV-2 exposure. Seropositivity increased over time with values reaching peaks after the epidemic waves (2.4% in May 2020; 16.2% in August 2020; 22.7% in December 2020 and 37% in February 2021). Conclusion: And increase of NAbs was observed over time and correlated with the post-epidemic waves of COVID-19 in Morocco.

[A Corynebacterium striatum endocarditis on a carrier of pacemaker]. / Endocardite à Corynebacterium striatum chez un porteur de stimulateur cardiaque.

We report a new case of a Corynebacterium striatum endocarditis on a carrier of a pacemaker. Corynebacterium striatum was isolated from blood culture, the pulse generator and the pacing lead. A literature review of Corynebacterium striatum endocarditis on a carrier of pacemaker was conducted.