Comprehensive genomic profiling enables the detection of genomic biomarkers in advanced solid tumors. However, efficient patient screening for the success of precision oncology remains challenging ...due to substantial barriers, such as genotyping costs and accessibility to matched therapies. To address these challenges, we launched GI‐SCREEN, a nationwide gastrointestinal cancer genomic screening project within the SCRUM‐Japan network in 2015 with the specific purpose of matching patients with a diverse portfolio of affiliated interventional targeted therapy trials. Subsequently, we initiated the molecular profiling projects GOZILA, MONSTAR‐SCREEN‐1, and MONSTAR‐SCREEN‐2, which incorporate tissue and plasma multiomics approaches to accurately identify patients with advanced solid tumors who would benefit from matched therapies. These projects have led to a significant increase in patient participation in targeted clinical trials and the approval of several therapeutics and companion diagnostics. Additionally, clinicogenomic analyses utilizing the SCRUM‐Japan database have provided new insights into the molecular mechanisms of advanced solid tumors. In this review, we describe the path to the realization of cancer precision medicine for patients with advanced solid tumors based on the SCRUM‐Japan GI‐SCREEN and MONSTAR‐SCREEN platforms.
Recent advances in precision oncology have highlighted the necessity of performing genotyping for patients with advanced cancer to select appropriate therapies. However, the pace of innovation in precision oncology is limited by the logistical hindrance of patient identification and the need for large‐scale cancer genomic screening platforms. In the submitted article, we reviewed the development of the SCRUM‐Japan GI‐SCREEN and MONSTAR‐SCREEN Project, a nationwide cancer genomic screening project in Japan, conducted to facilitate precision oncology.
Microsatellite Instability (MSI) status is an established predictive biomarker for the treatment of the anti‐programmed death 1 (PD‐1) antibody. The current approach to determine the MSI status in ...tumours requires matched normal DNA. Some mononucleotide microsatellite markers are known to have few variant alleles in both Caucasians and Asians. Therefore, the length of these microsatellite makers is almost confined within the quasi‐monomorphic variation range (QMVR). Considering the application of MSI testing for various types of cancers, a simple, sensitive and inexpensive method is desired. This study assessed the clinical utility of the QMVR for determining the MSI status in patients with unresectable metastatic colorectal cancer (mCRC). The study enrolled 435 patients with mCRC. The concordance of the MSI status in mCRC between the standard method using tumour DNA plus matched normal DNA and the testing method using only tumour DNA was evaluated. Eleven (2.5%) MSI‐high cases were detected by both the standard and testing methods. The sensitivity and specificity of the testing method were both 100%, indicating complete concordance between the methods. Among the mononucleotide markers, three and two patients showed discordance for NR‐21 and BAT‐25, respectively. Results from MSI testing with normal tissue indicated that four of five patients had rare germline variants outside the QMVR. For BAT‐26, NR‐24 and MONO‐27, all patients showed complete concordance. Using the QMVR, the MSI status of mCRC can be determined without matched normal DNA.
We assessed the utility of the Quasi‐Monomorphic Variation Range (QMVR) for determining the Microsatellite Instability (MSI) status in patients with metastatic colorectal cancer (mCRC). The MSI status between the standard method using tumour DNA plus matched normal DNA and the testing method using only tumour DNA was completely concordant. By using the QMVR, MSI status of mCRC can be determined without matched normal DNA.
Comprehensive genomic profiling enables genomic biomarker detection in advanced solid tumors. Here, to evaluate the utility of circulating tumor DNA (ctDNA) genotyping, we compare trial enrollment ...using ctDNA sequencing in 1,687 patients with advanced gastrointestinal (GI) cancer in SCRUM-Japan GOZILA (no. UMIN000016343), an observational ctDNA-based screening study, to enrollment using tumor tissue sequencing in the same centers and network (GI-SCREEN, 5,621 patients). ctDNA genotyping significantly shortened the screening duration (11 versus 33 days, P < 0.0001) and improved the trial enrollment rate (9.5 versus 4.1%, P < 0.0001) without compromising treatment efficacy compared to tissue genotyping. We also describe the clonal architecture of ctDNA profiles in ~2,000 patients with advanced GI cancer, which reinforces the relevance of many targetable oncogenic drivers and highlights multiple new drivers as candidates for clinical development. ctDNA genotyping has the potential to accelerate innovation in precision medicine and its delivery to individual patients.
The applicability of circulating tumor DNA (ctDNA) genotyping to inform enrollment of patients with cancer in clinical trials has not been established. We conducted a phase 2 trial to evaluate the ...efficacy of pertuzumab plus trastuzumab for metastatic colorectal cancer (mCRC), with human epidermal growth factor receptor 2 (HER2) amplification prospectively confirmed by tumor tissue or ctDNA analysis ( UMIN000027887 ). HER2 amplification was confirmed in tissue and/or ctDNA in 30 patients with mCRC. The study met the primary endpoint with a confirmed objective response rate of 30% in 27 tissue-positive patients and 28% in 25 ctDNA-positive patients, as compared to an objective response rate of 0% in a matched real-world reference population treated with standard-of-care salvage therapy. Post hoc exploratory analyses revealed that baseline ctDNA genotyping of HER2 copy number and concurrent oncogenic alterations adjusted for tumor fraction stratified patients according to efficacy with similar accuracy to tissue genotyping. Decreased ctDNA fraction 3 weeks after treatment initiation associated with therapeutic response. Pertuzumab plus trastuzumab showed similar efficacy in patients with mCRC with HER2 amplification in tissue or ctDNA, showing that ctDNA genotyping can identify patients who benefit from dual-HER2 blockade as well as monitor treatment response. These findings warrant further use of ctDNA genotyping in clinical trials for HER2-amplified mCRC, which might especially benefit patients in first-line treatment.
Clinical cancer genomic testing based on next‐generation sequencing can help select genotype‐matched therapy and provide diagnostic and prognostic information. Pathological tissue from malignant ...tumors obtained during routine practice are frequently used for genomic testing. This article is aimed to standardize the proper handling of pathological specimens in practice for genomic medicine based on the findings established in “Guidelines on the handling of pathological tissue samples for genomic medicine (in Japanese)” published by The Japanese Society of Pathology (JSP) in 2018. The two‐part practical guidelines are based on empirical data analyses; Part 1 describes the standard preanalytic operating procedures for tissue collection, processing, and storage of formalin‐fixed paraffin‐embedded (FFPE) samples, while Part 2 describes the assessment and selection of FFPE samples appropriate for genomic testing, typically conducted by a pathologist. The guidelines recommend that FFPE sample blocks be used within 3 years from preparation, and the tumor content should be ≥30% (minimum 20%). The empirical data were obtained from clinical studies performed by the JSP in collaboration with leading Japanese cancer genome research projects. The Japanese Ministry of Health, Labour, and Welfare (MHLW) recommended to comply with the JSP practical guidelines in implementing cancer genomic testing under the national health insurance system in over 200 MHLW‐designated core and cooperative cancer genome medicine hospitals in Japan.
Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as "oncogene addiction". A new generation of drugs that ...selectively target such "driver oncogenes" manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an "oncogenic driver" and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy.
We herein report a patient with KRAS wild-type non-small-cell lung cancer (NSCLC) with concurrent STK11 and KEAP1 mutations. A 53-year-old man visited a local doctor with a complaint of left shoulder ...swelling and pain. He was diagnosed with NSCLC cT4N0M1c stage IVB. A comprehensive genome profile test revealed mutations in STK11 and KEAP1 but no KRAS mutations. The patient was refractory to radiotherapy, immunotherapy, and chemotherapy. Thus, STK11 and KEAP1 mutations can be considered resistance mutations that confer resistance to various anticancer therapies in KRAS wild-type NSCLC.
Therapeutic strategies that target the tyrosine kinase MET hold promise for gastric cancer, but the mechanism underlying the antitumor activity of such strategies remains unclear. We examined the ...antitumor action of the MET tyrosine kinase inhibitor crizotinib (PF-02341066) in gastric cancer cells positive or negative for MET amplification. Inhibition of MET signaling by crizotinib or RNA interference-mediated MET depletion resulted in induction of apoptosis accompanied by inhibition of AKT and extracellular signal-regulated kinase phosphorylation in gastric cancer cells with MET amplification but not in those without it, suggesting that MET signaling is essential for the survival of MET amplification-positive cells. Crizotinib upregulated the expression of BIM, a proapoptotic member of the Bcl-2 family, as well as downregulated that of survivin, X-linked inhibitor of apoptosis protein (XIAP), and c-IAP1, members of the inhibitor of apoptosis protein family, in cells with MET amplification. Forced depletion of BIM inhibited crizotinib-induced apoptosis, suggesting that upregulation of BIM contributes to the proapoptotic effect of crizotinib. Crizotinib also exhibited a marked antitumor effect in gastric cancer xenografts positive for MET amplification, whereas it had little effect on those negative for this genetic change. Crizotinib thus shows a marked antitumor action both in vitro and in vivo specifically in gastric cancer cells positive for MET amplification.
A bovine hemoglobin (HbBv) or human adult hemoglobin (HbA) wrapped covalently by human serum albumins (HSAs), hemoglobin–albumin clusters (HbBv–HSA3 and HbA–HSA3), are artificial O2 carriers used as ...a red blood cell substitute. This article describes the physicochemical properties of the HbBv–HSA3 and HbA–HSA3 solutions, and their abilities to restore the systemic condition after resuscitation from hemorrhagic shock in anesthetized rats. The HbBv–HSA3 and HbA–HSA3, which have high colloid osmotic activity, showed equivalent solution characteristics and O2 binding parameters. Shock was induced by 50% blood withdrawal. Rats exhibited hypotension and significant metabolic acidosis. After 15 min, the rats were administered shed autologous blood (SAB), HbBv–HSA3, HbA–HSA3, or Ringer's lactate (RL) solution. Survival rates, circulation parameters, hematological parameters, and blood gas parameters were monitored during the hemorrhagic shock and for 6 h after administration. All rats in the SAB, HbBv–HSA3, and HbA–HSA3 groups survived for 6 h. The HbBv–HSA3 and HbA–HSA3 groups restored mean arterial pressure after the resuscitation. No remarkable difference was observed in the time courses of blood gas parameters in any resuscitated group except for the RL group. Serum biochemical tests showed increases in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the HbBv–HSA3 and HbA–HSA3 groups compared to the SAB group. Therefore, we observed other rats awakened after resuscitation with HbA–HSA3 for 7 days. The blood cell count, AST, and ALT recovered to the baseline values by 7 days. All the results implied that HbBv–HSA3 and HbA–HSA3 clusters provide restoration from hemorrhagic shock as an alternative material for SAB transfusion.
The molecular mechanism by which epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) induce apoptosis in non-small cell-lung cancer (NSCLC) cells that are positive for activating ...mutations of the EGFR remains unclear. In this study, we report the effects of the EGFR-TKI gefitinib on expression of the antiapoptotic protein survivin that have functional consequences in EGFR mutation-positive NSCLC cells. Immunoblot analysis revealed that gefitinib downregulated survivin expression, likely through inhibition of the PI3K-AKT signaling pathway, in NSCLC cells positive for EGFR mutation. Stable overexpression of survivin attenuated gefitinib-induced apoptosis and also inhibited the antitumor effect of gefitinib in human tumor xenografts. Furthermore, the combination of survivin overexpression with inhibition of the gefitinib-induced upregulation of the proapoptotic protein BIM attenuated gefitinib-induced apoptosis to a greater extent than either approach alone. Our results indicate that downregulation of survivin plays a pivotal role in gefitinib-induced apoptosis in EGFR mutation-positive NSCLC cells. Furthermore, they suggest that simultaneous interruption of the PI3K-AKT-survivin and MEK-ERK-BIM signaling pathways is responsible for EGFR-TKI-induced apoptotic death in these cells.
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