New clinical trial design in precision medicine: discovery, development and direction.

In the era of precision medicine, it has been increasingly recognized that individuals with a certain disease are complex and different from each other. Due to the underestimation of the significant heterogeneity across participants in traditional "one-size-fits-all" trials, patient-centered trials that could provide optimal therapy customization to individuals with specific biomarkers were developed including the basket, umbrella, and platform trial designs under the master protocol framework. In recent years, the successive FDA approval of indications based on biomarker-guided master protocol designs has demonstrated that these new clinical trials are ushering in tremendous opportunities. Despite the rapid increase in the number of basket, umbrella, and platform trials, the current clinical and research understanding of these new trial designs, as compared with traditional trial designs, remains limited. The majority of the research focuses on methodologies, and there is a lack of in-depth insight concerning the underlying biological logic of these new clinical trial designs. Therefore, we provide this comprehensive review of the discovery and development of basket, umbrella, and platform trials and their underlying logic from the perspective of precision medicine. Meanwhile, we discuss future directions on the potential development of these new clinical design in view of the "Precision Pro", "Dynamic Precision", and "Intelligent Precision". This review would assist trial-related researchers to enhance the innovation and feasibility of clinical trial designs by expounding the underlying logic, which be essential to accelerate the progression of precision medicine.

Pan-cancer efficacy and safety of anlotinib plus PD-1 inhibitor in refractory solid tumor: A single-arm, open-label, phase II trial.

The combination of immunotherapy and antiangiogenic agents for the treatment of refractory solid tumor has not been well investigated. Thus, our study aimed to evaluate the efficacy and safety of a new regimen of anlotinib plus PD-1 inhibitor to treat refractory solid tumor. APICAL-RST is an investigator-initiated, open-label, single-arm, phase II trial in patients with heavily treated, refractory, metastatic solid tumor. Eligible patients experienced disease progression during prior therapy without further effective regimen. All patients received anlotinib and PD-1 inhibitor. The primary endpoints were objective response and disease control rates. The secondary endpoints included the ratio of progression-free survival 2 (PFS2)/PFS1, overall survival (OS) and safety. Forty-one patients were recruited in our study; 9 patients achieved a confirmed partial response and 21 patients had stable disease. Objective response rate and disease control rate were 22.0% and 73.2% in the intention-to-treat cohort, and 24.3% and 81.1% in the efficacy-evaluable cohort, respectively. A total of 63.4% (95% confidence interval [CI]: 46.9%-77.4%) of the patients (26/41) presented PFS2/PFS1 >1.3. The median OS was 16.8 months (range: 8.23-24.4), and the 12- and 36-month OS rates were 62.8% and 28.9%, respectively. No significant association was observed between concomitant mutation and efficacy. Thirty-one (75.6%) patients experienced at least one treatment-related adverse event. The most common adverse events were hypothyroidism, hand-foot syndrome and malaise. This phase II trial showed that anlotinib plus PD-1 inhibitor exhibits favorable efficacy and tolerability in patients with refractory solid tumor.

Targeted therapy for intractable cancer on the basis of molecular profiles: An open-label, phase II basket trial (Long March Pathway).

Purpose: We evaluated he effects of molecular guided-targeted therapy for intractable cancer. Also, the epidemiology of druggable gene alterations in Chinese population was investigated. Materials and methods: The Long March Pathway (ClinicalTrials.gov identifier: NCT03239015) is a non-randomized, open-label, phase II trial consisting of several basket studies examining the molecular profiles of intractable cancers in the Chinese population. The trial aimed to 1) evaluate the efficacy of targeted therapy for intractable cancer and 2) identify the molecular epidemiology of the tier II gene alterations among Chinese pan-cancer patients. Results: In the first stage, molecular profiles of 520 intractable pan-cancer patients were identified, and 115 patients were identified to have tier II gene alterations. Then, 27 of these 115 patients received targeted therapy based on molecular profiles. The overall response rate (ORR) was 29.6% (8/27), and the disease control rate (DCR) was 44.4% (12/27). The median duration of response (DOR) was 4.80 months (95% CI, 3.33-27.2), and median progression-free survival (PFS) was 4.67 months (95% CI, 2.33-9.50). In the second stage, molecular epidemiology of 17,841 Chinese pan-cancer patients demonstrated that the frequency of tier II gene alterations across cancer types is 17.7%. Bladder cancer had the most tier-II alterations (26.1%), followed by breast cancer (22.4%), and non-small cell lung cancer (NSCLC; 20.2%). Conclusion: The Long March Pathway trial demonstrated a significant clinical benefit for intractable cancer from molecular-guided targeted therapy in the Chinese population. The frequency of tier II gene alterations across cancer types supports the feasibility of molecular-guided targeted therapy under basket trials.

Privacy-Preserving Decision-Tree Evaluation with Low Complexity for Communication.

Due to the rapid development of machine-learning technology, companies can build complex models to provide prediction or classification services for customers without resources. A large number of related solutions exist to protect the privacy of models and user data. However, these efforts require costly communication and are not resistant to quantum attacks. To solve this problem, we designed a new secure integer-comparison protocol based on fully homomorphic encryption and proposed a client-server classification protocol for decision-tree evaluation based on the secure integer-comparison protocol. Compared to existing work, our classification protocol has a relatively low communication cost and requires only one round of communication with the user to complete the classification task. Moreover, the protocol was built on a fully homomorphic-scheme-based lattice that is resistant to quantum attacks, as opposed to conventional schemes. Finally, we conducted an experimental analysis comparing our protocol with the traditional approach on three datasets. The experimental results showed that the communication cost of our scheme was 20% of the cost of the traditional scheme.

Acquired EML4-ALK fusion and EGFR C797S in cis mutation as resistance mechanisms to osimertinib in a non-small cell lung cancer patient with EGFR L858R/T790M.

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) dramatically improve the clinical outcomes of non-small cell lung cancer (NSCLC) patients harboring EGFR -sensitive mutations. Despite the remarkable efficacy of first-and second-generation EGFR TKIs, disease relapse is inevitable. EGFR T790M mutation is a primary contributor to the acquired resistance to first- and second-generation EGFR TKIs. Osimertinib, which is an irreversible third-generation EGFR TKI, was designed for EGFR -activating mutations as well as the EGFR T790M mutation in patients with advanced NSCLC and has demonstrated a convincing efficacy. However, acquired resistance to osimertinib after treatment inevitably occurs. The acquired resistance mechanisms to osimertinib are highly complicated and not fully understood, encompassing EGFR -dependent as well as EGFR -independent mechanisms. Treatment approaches for patients progressing from osimertinib have not been established. We present a case of a stage IV lung adenocarcinoma patient harboring EGFR L858R, acquired T790M after treatment with first-line gefitinib. She then acquired a new EML4-ALK gene fusion after treatment with osimertinib. A combination targeted therapy of osimertinib plus alectinib was initiated, with a progression-free survival of 5 months without any serious adverse reaction. After disease progression, EGFR C797S in cis was detected with a loss of the EML4-ALK fusion by targeted next-generation sequencing. Then therapy was changed to pemetrexed combined with bevacizumab plus camrelizumab, but no obvious effect was observed. The patient had achieved an overall survival of 31 months. As far as we know, this was the first reported case that an EGFR -mutant NSCLC patient-acquired ALK fusion mediating resistance to osimertinib, and sequential EGFR C797S mutation mediating resistance to combined targeted therapy with osimertinib and alectinib. Our case shows that EML4-ALK fusion is a rare but critical resistance mechanism to osimertinib, and C797S mutation in cis may be an underlying mechanism of acquired resistance mutation in double TKIs therapy. Furthermore, molecular detection and rebiopsy play important roles in the selection of therapeutic strategies when the disease progresses.

Low-dose anti-VEGFR2 therapy promotes anti-tumor immunity in lung adenocarcinoma by down-regulating the expression of layilin on tumor-infiltrating CD8+T cells.

PURPOSE: Our study intended to explore how low-dose anti-angiogenic drugs affected anti-tumor immunity of tumor-infiltrating exhausted CD8+T cells and achieved better clinical response when combined with immunotherapy. We set out to find potential targets or predictive biomarker on CD8+T cells for immunotherapy. METHODS: We tested different doses of anti-VEGFR2 antibody combined with anti-PD1 antibody to treat LUAD in vivo and analyzed tumor-infiltrating CD8+T cells by flow cytometry. CD8+T cells overexpressing LAYN were co-cultured with LA795 cell lines to identify the function of LAYN in CD8+T cells. We also analyzed clinical samples from advanced LUAD patients treated with anti-angiogenesis therapy combined with immunotherapy. RESULTS: Low-dose anti-VEGFR2 antibody combined with anti-PD1 antibody treatment delayed tumor growth and prolonged the survival time of tumor-bearing mice. The number of tumor-infiltrating CD8+T cells was reduced and the expression of LAYN was down-regulated in tumor-infiltrating CD8+T cells in the low-dose anti-VEGFR2 combination group. It was found that LAYN inhibited the killing function of CD8+T cells. In patients with advanced LUAD who received anti-angiogenesis therapy combined with immunotherapy, the LAYN+CD8+T cell subpopulation in good responders was significantly higher than that in poor responders. Furthermore, we demonstrated the expression of LAYN was regulated by upstream transcription factor NR4A1. CONCLUSION: Low-dose anti-VEGFR2 antibody combined with anti-PD1 antibody therapy promoted anti-tumor immunity and the downregulation of LAYN in tumor-infiltrating CD8+T cells played an important role in this process. These findings had implications for improving the efficacy of immune checkpoint blockade therapy and further optimized clinical treatment guidelines in advanced LUAD.

Effect of smoking habits on the efficacy of EGFR-TKI plus anti-angiogenic agent in advanced EGFR-mutant NSCLC.

BACKGROUND: The types of epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC) patients who could obtain significant clinical benefit from the dual inhibition of EGFR/vascular EGFR (VEGFR) pathways remain unclear. No consensus has been reached on the significance of smoking habits in clinical benefit obtained from EGFR-TKI plus anti-angiogenic agents. METHODS: PubMed, EMBASE, and Cochrane databases for all phase II/III randomized clinical trials (RCTs) investigating the efficacy of EGFR-TKI combined with anti-angiogenic agents stratified by smoking habits (updated October 2021) were searched systematically. The primary outcomes were the pooled HRs for PFS/OS in smokers and non-smokers, and differences in efficacy of EGFR-TKI plus anti-angiogenic treatment between smokers and non-smokers, measured by difference in PFS and OS. RESULTS: Seven phase II/III RCTs involving 1452 patients were identified. The pooled analysis demonstrated that EGFR-TKI plus anti-angiogenic agent could decrease the risk of progression by 40% (HR, 0.60; 95%CI 0.48-0.75) in smokers when compared with EGFR-TKI alone, but not in non-smokers (HR, 0.92; 95%CI 0.68-1.25). The comparison analysis further demonstrated that EGFR-mutated NSCLC patients who smoked obtained greater progression-free survival (PFS) benefit from treatment with EGFR-TKI plus anti-angiogenic agents (HR, 0.68; 95%CI 0.51-0.91). Consistent with the results for PFS, smokers receiving EGFR-TKI plus anti-angiogenic agents appeared to exhibit better overall survival (OS) than non-smokers but not to a statistically significant degree (HR, 0.60; 95%CI 0.23-1.52). Meta-regression analysis revealed no significant effect of the line of treatment (P = 0.52), trial phase (P = 0.52), EGFR-TKI type (P = 0.13), or anti-angiogenic agent type (P = 0.50) on PFS effect sizes under multivariate models. CONCLUSION: Comprehensive analysis suggested that EGFR-TKI plus anti-angiogenic agents led to favorable PFS among smoking EGFR-mutant patients, comparable to nonsmokers, which might provide a useful guide for clinicians.

Risk and Incidence of Infection with Bevacizumab in Non-Small-Cell Lung Cancer Patients: A Meta-Analysis.

BACKGROUND: A previous meta-analysis suggested that use of bevacizumab is associated with an increased risk of infection in cancer patients. With the continuous accumulation of evidence in non-small-cell lung cancer (NSCLC), we performed a new, focused meta-analysis of randomized controlled trials (RCTs) to quantify the relative risk (RR) and incidence of infectious complications in those individuals treated with bevacizumab. METHODS: Electronic databases were searched, including PubMed, Embase, and Cochrane databases. Eligible studies were prospective randomized clinical trials of NSCLC patients treated with bevacizumab with toxicity data on infectious complications. RR, overall incidence rates, and 95% confidence intervals (CI) were calculated using fixed- or random-effects models, depending on the heterogeneity of the included studies. RESULTS: A total of 4,545 patients from 14 prospective RCTs were included in the meta-analysis. Treatment with bevacizumab was not associated with an increased risk of all-grade (RR 1.12, 95% CI: 0.84-1.49) or high-grade (RR 1.11, 95% CI: 0.86-1.41) infections, respectively. The summary incidences of all-grade and high-grade infections in patients receiving bevacizumab in the treatment group were 16.4% (95% CI: 15.7-17.2%) and 4.3% (95% CI: 3.0-6.1%), respectively. CONCLUSIONS: The use of bevacizumab is not associated with a significantly higher risk of infections in NSCLC patients. These data provide reassurance regarding the risk of infection in patients with NSCLC receiving bevacizumab.

Cetuximab and vemurafenib plus FOLFIRI (5-fluorouracil/leucovorin/irinotecan) for BRAF V600E-mutated advanced colorectal cancer (IMPROVEMENT): An open-label, single-arm, phase II trial.

BACKGROUND: Current therapeutic regimens for patients with v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E-mutated colorectal cancer show unsatisfactory efficacy. To improve outcomes in this area, we assessed the safety and efficacy of a new protocol using vemurafenib and cetuximab combined with FOLFIRI (5-fluorouracil/leucovorin/irinotecan) in patients with BRAF V600E-mutated colorectal cancer. METHODS AND MATERIALS: This was an investigator-initiated, open-label, single-arm, phase II trial conducted in patients with BRAF V600E-mutated advanced colorectal cancer. Patients were eligible to receive FOLFIRI combined with vemurafenib and cetuximab. The primary end-point was the objective response rate, and the secondary end-points included disease control rate, progression-free survival, overall survival and safety. This trial is registered with ClinicalTrials.gov, NCT03727763. RESULTS: Between 12th January 2018, and 18th June 2021, we screened 27 patients, 21 of which were enrolled in this study. Efficacy analysis showed that objective response rates were 81.0% (17/21; 95% confidence interval [CI] 57.4-93.7) in the intention-to-treat population and 85.0% (17/20, 95%CI 61.0-96.0) in the per-protocol population; two patients achieved complete response, and 15 patients achieved a partial response. In the entire cohort, the median progression-free survival was 9.7 months (95%CI 6.3-10.9), and the median overall survival for all patients was 15.4 months (95%CI 8.5-15.4). The most common adverse events (grade 3 to 4) were neutropenia (8/21), anaemia (3/21) and skin rash (3/21). CONCLUSION: Vemurafenib and cetuximab can be safely combined with the FOLFIRI regimen, showing promising antitumour activity and tolerable toxicity in patients with BRAF V600E-mutated advanced colorectal cancer. This regimen warrants a further randomised study in phase III clinical trials.

Prognostic value of tumor mutation burden in patients with advanced gastric cancer receiving first-line chemotherapy.

Background: Tumor mutation burden (TMB) is a promising biomarker positively associated with the benefit of immunotherapy and that might predict the outcome of chemotherapy. We described the prognostic value of TMB in advanced gastric cancer and explored the underlying mechanism. Methods: We enrolled 155 TMB-evaluated advanced gastric cancer patients and analyzed the relationship between clinicopathological characteristics and both overall survival (OS) and progression-free survival (PFS) among 40 patients treated with first-line chemotherapy. We further verified the distribution of TMB and analyzed the potential mechanism underlying the prognosis based on The Cancer Genome Atlas (TCGA) database. Results: Among the 155 patients, 29 (18.7%) were TMB-high (TMB ≥ 10), roughly the same as the proportion in the TCGA data. Of the 40 patients receiving first-line chemotherapy, the median OS (7.9 vs. 12.1 months; HR 3.18; p = 0.0056) and PFS (4.4 vs. 6.2 months; HR 2.94; p = 0.0099) of the tissue-tested TMB (tTMB)-high patients were inferior to those of the tTMB-low patients. Similarly, unfavorable median OS (9.9 vs. 12.1 months; HR 2.11; p = 0.028) and PFS (5.3 vs. 6.5 months; HR 2.49; p = 0.0054) were shown in the blood-tested TMB (bTMB)-high than in the bTMB-low patients. The Cox analysis demonstrated that both tTMB-high and bTMB-high were significant independent predictors of dreadful OS and PFS. The differentially expressed genes (DEGs) according to TMB status were most significantly enriched in the downregulated metabolic pathway among the TMB-high patients. Conclusions: TMB-high advanced gastric cancer patients accounted for around one-sixth and had a poorer prognosis than TMB-low patients when treated with first-line chemotherapy. The potential mechanism might be the downregulated metabolic activity in TMB-high patients.

Serum tumor markers for the prediction of concordance between genomic profiles from liquid and tissue biopsy in patients with advanced lung adenocarcinoma.

BACKGROUND: The concordance between mutations detected from plasma and tissue is critical for treatment choices of patients with advanced lung adenocarcinoma. METHODS: We prospectively analyzed the association of the serum tumor markers with the concordance between blood and tissue genomic profiles from 185 patients with advanced lung adenocarcinoma. The concordance was defined according to 3 criteria. Class 1 included all targetable driver mutations in 8 genes; class 2 included class 1 mutations plus mutations in KRAS, STK11, and TP53; class 3 included class 2 mutations plus tumor mutation burden (TMB) status. RESULTS: Collectively, 150 out of 185 patients had mutations in both tissue and plasma samples, while one patient was mutation-negative for both, resulting a concordance of 81.6%. The concordance rate for class 1 mutations was 80%, and 65% and 69% for class 2 and class 3, respectively. Carbohydrate antigen 19-9 (CA19-9) or cytokeratin 19 (CYFRA21-1) levels higher than the normal upper limit predicted the concordance of tissue and blood results in class 1 (P=0.005, P=0.011), class 2 (P=0.011, P<0.001), and class 3 (P=0.001, P=0.014). In class 1, the cutoff values of CA19-9 were 30, 36, and 284 U/mL to reach the concordance thresholds of 90%, 95%, and 100%, respectively (P=0.032, P=0.003, P=0.043). For CYFRA21-1, the cutoff values were 6, 18, and 52 µg/L (P=0.005, P=0.051, P=0.354). In class 2, the cutoff values for CYFRA21-1 were 18, 22, and 52 µg/L (P=0.001, P=0.001, P=0.052). In class 3, the cutoff values for CA19-9 were 36, 39, and 85 U/mL (P=0.003, P=0.001, P=0.008). For CYFRA21-1, the cutoff values were 22, 52, and 52 µg/L (P=0.900, P>0.99, P>0.99). When the sum score for 4 serum tumor markers was greater than 35, both class 1, class 2, and class 3 reached a predictive threshold of 90%. CONCLUSIONS: Serum tumor markers can be used as easy and practical clinical predictors of concordance in mutation profiles between blood and tissue samples from patients with advanced lung adenocarcinoma.

Effects of concomitant proton pump inhibitor use on immune checkpoint inhibitor efficacy among patients with advanced cancer.

Background: The present study aimed to evaluate the effects of concomitant proton pump inhibitor (PPI) use on immune checkpoint inhibitor (ICI) efficacy among advanced cancer patients. Methods and Materials: A systematic literature search of electronic database was performed to identify all potential reports. Then, meta-analyses were conducted to obtain pooled HRs with 95% CIs, which reveal the influence of PPI use on PFS and OS in patients receiving ICI treatment. Results: A total of 7 studies with 3,647 advanced cancer patients fulfilled the inclusion criteria. The impact of PPI use was then evaluated on 3,340 patients for PFS and 3,647 patients for OS. Concomitant PPI use has a detrimental effect on the efficacy of ICIs that PPI use increased the risk of progression by 28% (HR = 1.28, 95% CI 1.17-1.40; I2 = 31.3%, Q test P = .21) when compared to those not receiving PPIs. Similarly, the meta-analysis showed that PPI use was also associated with shorter OS of advanced cancer patients receiving ICIs that PPI use increased risk of death by 39% (HR = 1.39, 95% CI 1.26-1.54; I2 = 36.5%, Q test P = .16). Sensitivity analysis showed that the pooled HRs were constant after excluding one study at a time, and no significant publication biases were detected. Conclusion: The meta-analysis suggested that concomitant PPI use is significantly associated with low clinical benefit in ICI treatment, revealing a significantly reduced PFS and OS in advanced cancer patients receiving ICIs who are also exposed to PPI.

Primary squamous cell carcinoma of pancreas: a population-based study.

BACKGROUND: Primary squamous cell carcinoma of pancreas (SCCP) is an extremely rare pathological subtype of pancreatic cancer of ductal origin. Due to its rarity, most previous studies on SCCP focused on case reports or series and the clinio-pathological characteristics of SCCP patients remain unclear. METHODS: A retrospective analysis of SCCP patients registered in the Surveillance, Epidemiology and End Results (SEER) database from 1988 to 2016 were performed, and clinical characteristics and prognosis of these patients were also further determined. RESULTS: A total of 373 patients diagnosed with SCCP were identified. Most SCCP patients 154/243 (63.4%) SCCP patients had distant metastases. The prognosis of SCCP patients was poor with a median overall survival (mOS) of only 3.0 months (95% CI, 2.0-5.0). The 6-month, 1-year and 2-years survival rate were 25.6%, 13.2% and 5.7%, respectively. The prognosis of SCCP patients became much worse with the increasing age (P=0.01) and distant metastases (P<0.01). Cancer-directed surgery, chemotherapy and radiotherapy could significantly prolong the survival time for SCCP patients (P<0.01 for all). Multivariate Cox analysis showed that only distant metastases were independent prognostic factors of worse survival in SCCP patients (HR =1.58, 95% CI, 1.18-2.12). Conversely, both cancer-directed surgery and chemotherapy were an independent protective factor that decreased the risk of death by 66% (HR =0.18, 95% CI, 0.11-0.29) and 46% (HR =0.54, 95% CI, 0.43-0.68) for SCCP patients. CONCLUSIONS: SCCP is a rare type of pancreatic malignancies with poor prognosis. The present study could provide some useful information for future management and prospective studies for SCCP patients.

HER2 Splice Site Mutation c.1899-1G>A as the Potential Acquired Resistance to Trastuzumab in a Patient with HER2-Positive Gastric Adenocarcinoma.

The addition of trastuzumab to chemotherapy regimen is the standard of care for human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer; however, most patients eventually acquire trastuzumab resistance. Although some resistance mechanisms to trastuzumab-based regimens have been proposed, further understanding is required for developing therapeutic strategies to overcome the resistance. In the present work, we attempted to determine the possible resistance mechanism to trastuzumab in a patient with HER2-positive stage IV gastric adenocarcinoma. In this study, we first report the nucleotide change c.1899-1G>A at the intron 15 acceptor splice site promoting exon 16 deletion of HER2 as the potential mechanism of trastuzumab resistance in HER2-positive gastric adenocarcinoma. KEY POINTS: The combination of trastuzumab with chemotherapy is considered to be the standard therapy for HER2-positive advanced gastric cancer (GC), but most of the patients eventually acquire trastuzumab resistance. The mechanisms of resistance to trastuzumab in GC are poorly characterized. To the best of the authors' knowledge, this study is the first to implicate HER2 c.1899-1G>A, which results in exon 16 skpping, as the acquired resistance mechanism to trastuzumab in HER2-positive gastric adenocarcinoma. This work provides insights into the potential molecular mechanism of trastuzumab resistance, which is crucial in developing effective therapeutic strategies for HER2-positive GC patients refractory to trastuzumab.

Clinical characteristics and prediction analysis of the recovered COVID-19 patients with re-detectable positive RNA test.

BACKGROUND: Previous studies have unveiled the occurrence of re-detectable positive (RP) RNA test result after hospital discharge among recovered COVID-19 patients, but the clinical characteristics of RP patients (RP patients) and the potential features affecting RP RNA test outcome remain unclear. METHODS: A total of 742 COVID-19 patients discharged between March 1st, 2020 and March 20th, 2020 were enrolled. All patients were followed-up for SARS-CoV-2 RNA test and RP patents were identified. The clinical characteristics between RP patients and NRP patients were compared, and the potential features affecting re-detectable RNA test outcome were further evaluated. RESULTS: Up to April 9th, 2020, 60 recovered patients (8.09%) had been re-detected to be SARS-CoV-2 RNA positive. Among those 60 RP patients, the median RP time was 12 days from the last negative result of SARS-CoV-2 RNA test or 10 days from hospital discharge. RP patients were prone to be older, having mild/moderate conditions, unilateral lung involvement and fatigue, chills, stuffy or runny nose, with high lymphocyte count. Multivariate logistic analysis and COX regression analysis demonstrated that age, lymphocyte count, urea nitrogen, stuffy or runny nose as well as lung involvement were independently associated with RP RNA test (P<0.05). CONCLUSIONS: Older patients accompanied with stuffy or runny nose, low urea nitrogen as well as unilateral lung involvement were more likely to develop RP RNA test result after hospital discharge. Therefore, we strongly suggest using broncho-alveolar lavage fluid for RNA detection, extending quarantine time, and conducting continual follow-up medical examination for those discharged patients.

Metastatic Low-Grade Sarcoma with CARS-ALK Fusion Dramatically Responded to Multiple ALK Tyrosine Kinase Inhibitors: A Case Report with Comprehensive Genomic Analysis.

This article reports a case of advanced metastatic low-grade sarcoma. The patient was diagnosed with an inoperable large (14 × 12 cm) lesion on his neck in September 2015 and underwent two ineffective chemotherapies in the following 4 months. Interestingly, although several pathologists could not agree on the histopathological diagnosis, the precise molecular pathological diagnosis was obtained using next-generation sequencing (NGS) and finally brought excellent therapeutic effects. The patient was detected to have CARS-ALK fusion by NGS and then was successfully treated with crizotinib orally. He received surgical resection of primary and metastatic lesions after tumor shrinkage. The combined treatment brought a durable response for 40 months. Although the tumor recurred in July 2019, the patient has been responding well to the second-line ALK tyrosine kinase inhibitor alectinib to date. We performed whole genome sequencing on the patient's primary, metastatic, and recurrent tumors and did comprehensive genomic analysis. Furthermore, our analysis results revealed that a whole genome duplication event might have happened during tumorigenesis of this case. KEY POINTS: To our best knowledge, this is the first report of a very successful treatment with first- and second-line ALK tyrosine kinase inhibitors for CARS-ALK fusion-positive metastatic low-grade sarcoma. Molecular pathological result can guide precision treatment for sarcoma, even when the exact histopathology cannot be obtained. Multiple samples from this patient were analyzed using whole genome sequencing. Results provided detailed genomic characteristics and showed tumor evolution of this low-grade sarcoma case. A whole genome duplication event might have happened during tumorigenesis of this low-grade sarcoma case.

A meta-analysis comparing responses of Asian versus non-Asian cancer patients to PD-1 and PD-L1 inhibitor-based therapy.

Background: Subgroup analysis of clinical trials of PD-1/PD-L1 inhibitors have reported ethnic differences in outcomes. We systematically collected published data and performed a meta-analysis to compare therapeutic efficacy in Asian and non-Asian patients receiving PD-1/PD-L1 inhibitors. Methods: Eligible studies included phase II and III prospective clinical trials with available subgroup data on Asian versus non-Asian populations. Overall survival (OS) and progression-free survival (PFS) were used to evaluate differences in outcome between Asian versus non-Asian cancer patients. Results: A total of 11,020 cancer patients from 19 prospective randomized controlled clinical trials were included. The overall estimated HR for OS was 0.69 with 95% CI of 0.61-0.77 in Asian versus 0.82 with 95% CI of 0.77-0.88 in non-Asian patients. The estimated hazard ratio (HR) for PFS measured 0.54 (95% CI, 0.32-0.76) and 0.69 (95% CI, 0.54-0.85) in Asian and non-Asian patients, respectively. Pooled ratios of OS HRs and PFS HRs reported in Asian versus non-Asian cancer patients were 0.84 (95% CI, 0.75-0.94) and 0.78 (95% CI, 0.59-0.97), respectively. Conclusions: This meta-analysis shows for the first time that Asian cancer patients have a significantly improved survival benefit than non-Asian patients receiving PD-1/PD-L1 inhibitor-based therapy.

Tumor mutation burden in Chinese cancer patients and the underlying driving pathways of high tumor mutation burden across different cancer types.

BACKGROUND: Tumor mutation burden (TMB) has an important association with immunotherapy responses. TMB in the Chinese population has not been well established. Finding differences between the Chinese and Caucasian populations and elucidating the underlying biological mechanisms of high TMB might help develop more precise and effective means for TMB and immunotherapy response prediction. METHODS: Chinese cancer patients fresh tissue (n=2,177), formalin-fixed, paraffin-embed (FFPE) specimens (n=3,294), and pleural fluid (n=189) were profiled using a 295- or 520-gene next-generation sequencing (NGS) panel. The association of the TMB status with a series of molecular features and biological pathways was determined using bootstrapping. RESULTS: TMB, measured by 295- or 520-cancer-related gene panels, was correlated with whole-exome sequencing (WES) TMB based on the in silico simulation in The Cancer Genome Atlas cohort. The median TMB of our data was slightly higher than that from the Foundation Medicine Inc. (FMI) dataset. TMB was also slightly different within the same cancer type between the Chinese and Caucasian population. We discovered that the underlying pathways of TMB status varied greatly and sometimes had an opposite association with TMB across different cancer types. Moreover, we developed a 23-gene and a 16-gene signature to predict TMB prediction for lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), respectively, indicating a histology-specific mechanism for driving high-TMB in lung cancer. CONCLUSIONS: TMB varies among different ethnic populations. Our findings extend the knowledge of the underlying biological mechanisms for high TMB and might be helpful for developing more precise and accessible TMB assessment panels and algorithms in more cancer types.