Search

Background BRAF V600E mutation represents a group of colorectal carcinoma with poor prognosis. Although treatment strategies have been recommended after clinical investigations, the progression-free survival is short and unsatisfying. Case presentation Here, we present the case of a 28-year-old male diagnosed with ascending colon adenocarcinoma with multiple liver metastases. Treatment with FOLFIRI plus cetuximab and vemurafenib achieved partial response, following which the patient received conversion surgery with clear resection margin. After disease recurrence, he received combination treatment of nivolumab and regorafenib. Until August 2020, the patient achieved a partial response with more than 12 months progression-free survival. Circulating tumor DNA (ctDNA) was monitored during the patient's treatment. His ctDNA fractions exhibited significant elevation two months before disease progression. As a comparison, the tumor markers were not elevated until the patient was confirmed PD through CT imaging. Conclusion This case exemplifies how liquid biopsy and ctDNA sequencing can aid in real-time molecular characterization of tumors.

Background Previous studies have suggested the efficacy of HER2 antibody (trastuzumab) in scrotal Paget's disease with HER2 amplification or overexpression. However, no report about the effectiveness of HER2 inhibitor (pyrotinib) in those patients has been provided until now. Case presentation We present a case of a Chinese patient with bone-metastatic scrotal Paget's disease harboring triple uncommon HER2 mutations (R678Q/S310Y/S310F). Due to poor conditions (severe anemia, thrombocytopenia, ECOG PS3), this patient could not tolerate traditional chemotherapy and radiotherapy. Then, the patient participated in a registered clinical trial (NCT03239015) about basket trial for intractable cancer. The patient received pyrotinib (400 mg po qd) and achieved a partial response for 4.0 months. Conclusion This is the first report describing a patient with scrotal Paget's disease harboring triple uncommon HER2 mutation who responds well to pyrotinib. This case suggested that HER2 mutation is also a potential biomarker for treatment in extramammary Paget's disease and pyrotinib may be an ideal choice for these patients.

Background: Metastasis suppressor 1 (MTSS1), a potential metastasis suppressor gene associated with tumor progression, may play an important role in cancer development. Our previous study demonstrated that MTSS1 was downregulated significantly when gastric cancer (GC) progressed and metastasized, suggesting that MTSS1 may be involved in the physiopathologic mechanism of GC. Purpose: The objective of this study was to evaluate the effect of MTSS1 expression on the biological behavior of gastric cancer cell both in vitro and in vivo. Materials and methods: The gain-and-loss function of MTSS1 in GC cells were analyzed after transfection with pEGFP-N1-MTSS1 and ShRNA431. Proliferation and invasion abilities were measured by means of plate clone formation assay and transwell assay. To further explore the underlying mechanism of MTSS1-induced tumor restrain, cell cycle distribution was analyzed using flow cytometry. Results: The results revealed that overexpression of MTSS1 significantly reduced proliferation, migration and invasion of GC cells in vivo and in vitro, while downregulation of MTSS1 had the opposite biological manifestations. Moreover, overexpression of MTSS1 induced accumulation of GC cells in G2/M phase, increased phosphorylated Cdc2 expression and decreased Cdc25C and cyclinB1 levels, suggesting MTSS1 could cause G2/M cell cycle arrest. Conclusion: Our data provided insight into an important role for MTSS1 in suppressing tumor cell proliferation, invasion and migration, indicating that MTSS, as a functional tumor suppressor in GC, could be a potential therapeutic target to prevent GC metastasis.

In patients without tissue availability at presentation, the analysis of cell-free DNA derived from liquid biopsy samples, in particular from plasma, represents an established alternative for providing epidermal growth factor receptor (EGFR) mutational testing for treatment decision-making. Compared with quantitative polymerase chain reaction and digital polymerase chain reaction-targeted methods, next-generation sequencing can provide more information about tumor molecular alterations, especially EGFR mutations. Here, we present a case of a patient with non-small cell lung cancer (NSCLC) harboring 3 uncommon mutations of EGFR-R670W in exon 17 and H833V, and H835L in exon 21, as shown by next-generation sequencing of plasma cell-free DNA. To the best of our knowledge, this is the first case report of a patient harboring the R670W mutation. The patient responded well to second-generation tyrosine kinase inhibitors (TKIs). T790M is an acquired resistant mutation in patients with R670W, H833V, and H835L. This is also the first case of a patient harboring the H833V/H835L/T790M triple mutation; the patient had a good response to the third-generation TKI osimertinib. In this work, we also performed a literature review on the clinical characteristics of NSCLC patients with the H833V/H835L double mutation, together with a descriptive analysis about their response to EGFR TKI monotherapy as a first-line treatment, according to data from previous case reports. The results showed that the cohort of NSCLC patients with H833V/H835L responded well to EGFR TKIs; thus, before treatment in clinical practice, screening for EGFR mutations should be conducted and EGFR TKIs should be preferred in NSCLC patients with H833V/H835L mutations.