A Rare Case of Nasal Sarcoma with BCOR Internal Tandem Duplication Showing Complete Pathologic Response to the VDC-IE Chemotherapy Protocol.

Sarcoma with BCOR genetic alteration is an exceptionally rare and emerging subtype of sarcoma. It is categorized into two types: BCOR-related gene fusions such as BCOR::CCNB3 sarcomas and other BCOR-rearranged sarcoma and sarcomas with internal tandem duplication of BCOR genes such as infantile undifferentiated round cell sarcomas and primitive myxoid mesenchymal tumors of infancy. BCOR::CCNB3 sarcomas predominantly arise in bone rather than soft tissue and exhibit a higher occurrence in children and adolescent males, whereas sarcomas with BCOR internal tandem duplication show a wider age range but usually arise in the first year of life. Due to their rarity, there is ongoing debate and uncertainty regarding the best treatment approach, with a lack of specific clinical trials addressing these tumors. In this report, we present a unique case of sarcoma with internal tandem duplication of BCOR gene originating in the nasal region. The tumor was successfully and completely resected using the standard VDC-IE chemotherapy protocol, resulting in an unprecedented 100 percent tumor necrosis. The patient has completed the protocol and remains recurrence-free 13 months after diagnosis. This case suggests potential efficacy of the standard VDC-IE protocol in achieving remarkable responses in BCOR rearrangement sarcomas, including the internal tandem duplication subtype. However, further studies are needed to determine the optimal treatment strategies for this disease.

The O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and clinical outcomes of Ewing sarcoma patients treated with irinotecan and temozolomide.

Background: There remains an unmet need to identify molecular biomarkers in Ewing sarcoma (ES). We sought to assess the influence of the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation on response and progression-free survival (PFS) following initiation of irinotecan and temozolomide (IT), PFS following initiation of vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (VDC-IE), and overall survival (OS). Materials and methods: Data of advanced ES patients, treated with IT were retrospectively collected. Patients were required to have progression after prior VDC-IE. MGMT promoter methylation was assessed on non-decalcified Formalin-fixed paraffin embedded (FFPE) tissue using methylation sensitive restriction enzyme-quantitative PCR (MSRE-qPCR). Survival was estimated by the Kaplan-Meier method. Results: A total of 20 ES patients underwent MGMT promoter methylation testing, and were eligible for analysis. Five patients (25%) had methylated MGMT, whereas the remaining (15; 75%) had unmethylated promoter. Five (25%) had objective response to IT, with no observed difference by promoter methylation (p = 0.76). Median PFS from initiation of IT for methylated vs. unmethylated MGMT patients was 4.9 and 1.2 months, respectively, p = 0.69. Median PFS from date of initiation of VDC-IE was significantly superior in the methylated group; 27.8 vs. 8.6 months, p = 0.034. Median OS was superior but not statistically significant in the methylated group. Conclusion: MGMT-promoter methylation did not correlate with clinical activity or outcomes following the IT regimen for advanced ES. However, methylated MGMT predicted significantly superior PFS following initiation of the standard VDC-IE protocol.

A Comparative Analysis of Breast and Ovarian Cancer-related Gene Mutations in Canadian and Saudi Arabian Patients with Breast Cancer.

Previous reports have indicated that patients with breast cancer who are from the Eastern Province of Saudi Arabia have a different gene expression profile from that known for their age-matched North American population. In the present study, breast tumor samples from Canadian and Saudi Arabian patients were screened for known and unknown mutations within BRCA1 and BRCA2 as well as 21 additional genes, including, ATM, BARD1, CDH1, P53, EPCAM, MSH6, and RAD50, which have been implicated in breast and ovarian cancer predisposition. A total of 129 non-synonymous mutations were identified by Ion Torrent amplicon sequencing. Forty-one mutations in 18 genes were unique to the Canadian population and 59 mutations in 20 genes were unique to the Saudi Arabian population. A total of 55/129 unique mutations in 22 genes were not previously reported in the database. Twenty-nine mutations in 16 genes were common to both populations; one of these mutations was not previously reported in the database. The most frequently mutated gene in both populations was the BRCA2 gene, followed by BRCA1 and TP53. Unique to this work is the identification of mutations frequently found in the Saudi Arabian population that are rare in the Canadian population. This work will allow direction of genetic analysis resources toward the clinical needs of each particular population.

Novel KRAS gene mutations in sporadic colorectal cancer.

INTRODUCTION: In this article, we report 7 novel KRAS gene mutations discovered while retrospectively studying the prevalence and pattern of KRAS mutations in cancerous tissue obtained from 56 Saudi sporadic colorectal cancer patients from the Eastern Province. METHODS: Genomic DNA was extracted from formalin-fixed, paraffin-embedded cancerous and noncancerous colorectal tissues. Successful and specific PCR products were then bi-directionally sequenced to detect exon 4 mutations while Mutector II Detection Kits were used for identifying mutations in codons 12, 13 and 61. The functional impact of the novel mutations was assessed using bioinformatics tools and molecular modeling. RESULTS: KRAS gene mutations were detected in the cancer tissue of 24 cases (42.85%). Of these, 11 had exon 4 mutations (19.64%). They harbored 8 different mutations all of which except two altered the KRAS protein amino acid sequence and all except one were novel as revealed by COSMIC database. The detected novel mutations were found to be somatic. One mutation is predicted to be benign. The remaining mutations are predicted to cause substantial changes in the protein structure. Of these, the Q150X nonsense mutation is the second truncating mutation to be reported in colorectal cancer in the literature. CONCLUSIONS: Our discovery of novel exon 4 KRAS mutations that are, so far, unique to Saudi colorectal cancer patients may be attributed to environmental factors and/or racial/ethnic variations due to genetic differences. Alternatively, it may be related to paucity of clinical studies on mutations other than those in codons 12, 13, 61 and 146. Further KRAS testing on a large number of patients of various ethnicities, particularly beyond the most common hotspot alleles in exons 2 and 3 is needed to assess the prevalence and explore the exact prognostic and predictive significance of the discovered novel mutations as well as their possible role in colorectal carcinogenesis.