Professor Huang Huiqiang: The CSF-ctDNA 5 gene model is first proposed in the world to predict DLBCL central invasion, which has great clinical significance

*Only for medical professionals to read the reference guide.
Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype of non-Hodgkin's lymphoma.
Central nervous system (CNS) invasion may occur in some patients.

However, the clinical CNS-IPI prognostic scoring system cannot accurately predict whether patients with high-risk central invasion will have central invasion in the future.
For example, CNS-IPI high-risk does not have central invasion, while some low-risk and intermediate-risk patients have central involvement.

CNS-IPI is clinically simple and practical, but not accurate enough.

Therefore, in order to improve the predictive performance of central involvement of DLBCL and avoid over-treatment of some patients (systemic MTX prevention is highly toxic), more and more experts believe that trying to use molecular indicators to increase the accuracy of prediction is the only way.

Cerebrospinal fluid circulating tumor DNA (CSF-ctDNA) can reflect the mutational molecular characteristics of solid tumors of the nervous system (glioma, etc.
), and it has been confirmed that it plays an important role in assisting diagnosis and predicting efficacy.

So, can liquid biopsy of cerebrospinal fluid samples benefit the diagnosis and treatment of central lymphoma? Recently, the editor is honored to specially invite Professor Huang Huiqiang and Professor Wang Xiaoxiao from the Lymphoma Center of Sun Yat-sen University Tumor Hospital to interpret the application value of liquid biopsy in the precise diagnosis and treatment of central lymphoma based on the team’s latest clinical research and exploration results.

Professor Huang's team cooperated with Shihe Gene and used Shihe Gene Xuemosheng™ Large Panel (475 Gene) test to evaluate the correlation between CSF-ctDNA and DLBCL central nervous system violations.

The research results were published in Clinical and Translational Medicine (IF=7.
919), and will be displayed as a poster at the American Annual Meeting of Hematology (ASH) in 2020.The study used multi-sample NGS detection, the first internationally to use cerebrospinal fluid ctDNA detection to evaluate whether DLBCL has central nervous system involvement, and found that high levels of CSF-ctDNA are correlated with higher CNS-IPI scores, which again confirms CSF-ctDNA An important role in the auxiliary diagnosis of central lymphoma.

At the same time, this study preliminarily proved that BTG2, CXCR4, DUSP2, ETV6 and PIM1 genes may be related to the high risk of central recurrence of DLBCL.
The importance of clinical diagnosis, treatment and prognosis.

Professor Huang Huiqiang Professor Huang Huiqiang wonderful video 01 You are an expert in the treatment of lymphoma, can you introduce the current difficulties in diagnosis and treatment of secondary central nervous system lymphoma? In recent years, research on diffuse large B-cell lymphoma has progressed rapidly.

At present, R-CHOP is still the most basic treatment plan.
70% of patients can survive long-term through treatment, but about 30% of patients have unsatisfactory results.
One of the reasons is recurrence or death caused by central invasion.

Therefore, once diagnosed with central metastasis, the prognosis may be poor.

Current treatments, including methotrexate (MTX), cytarabine (Ara-c), autologous hematopoietic stem cell transplantation, CAR-T therapy, etc.
have certain curative effects, but the long-term curative effect is still not ideal.

So, can the central invasion of lymphoma be avoided through pre-prevention? Patients with aggressive lymphoma with high-risk factors are clinically recommended for prevention.
Unfortunately, the current intrathecal injection is not effective.
In addition, try high-dose MTX intravenous injection for prevention, such as 3-3.
5g/m2 MTX, 4 courses The above treatment and prevention effects are better.

However, a report from a US colleague at the 2020 ASH Annual Meeting suggests that the preventive effect of high-dose MTX is still not satisfactory.

Therefore, once the high-risk diffuse large B-cell lymphoma has secondary central invasion, the prognosis is quite poor, which is the difficulty of diffuse large B-cell lymphoma at this stage.

02After listening to your introduction, can it be understood that clearly distinguishing lymphoma patients who are at risk of central nervous system invasion is the key to improving the prognosis? Is there currently any clinical method to predict the risk of central nervous system invasion? Past data and retrospective studies have shown that the clinical features of diffuse large B-cell lymphoma with central involvement, such as patients with a high risk of CNS-IPI of 4 or more, have about 10% central involvement within two years.

In addition, patients with double-strike, CD5 positive, adrenal/breast/testicular invasion, MCD type, intravascular large B and IgM secretion type have a higher probability of central metastasis, and about 10%-30% will occur within 2-3 years Central violation.

However, the current preventive measures are not effective enough.
Some traditional clinical examinations, such as MRI, CT, and cerebrospinal fluid routine examinations, are difficult to determine the central violation in the early stage.
When there are clinical symptoms, CT or cytology can be used to determine Central violation.

In recent years, flow cytometry has promoted early diagnosis, but the effect is still not ideal, and the method is difficult to master and the stability is poor.

At present, cfDNA detection, a modern molecular biology method that is clinically concerned, uses NGS technology to find information about trace gene mutations related to B/T cell lymphoma in cerebrospinal fluid, assist early diagnosis, and identify high-risk patients.
This is a relatively cutting-edge research.
content.

Of course, the clinical application value of cfDNA is still not completely clear, but it does bring us a lot of new and useful information.

Past studies have preliminarily proved the sensitivity and specificity of blood ctDNA testing, which can indicate the remission quality of treatment and the dynamic changes of minimal residual disease.
For example, a report by an American expert at the 2020 ASH meeting showed that 19 patients underwent cerebrospinal fluid cfDNA examination.
42% of the patients tested positive and followed up for half a year, and 29% of the patients had central involvement, which is obviously earlier than conventional clinical methods (imaging) to find the real high-risk patients.

Recently, our team published an article in collaboration with Shihe Gene.
For the first time, a detailed analysis of 67 cases of newly treated high-risk lymphoma patients with cfDNA dynamic monitoring results in the cerebrospinal fluid was suggested to indicate the risk of central metastasis.
It was found that 20 patients were positive for cfDNA.
These patients The imaging examination was normal, without any clinical symptoms. During the follow-up, it was found that 9 patients have finally been diagnosed with central lymphoma invasion so far.

Therefore, our research results show that cerebrospinal fluid cfDNA biopsy can detect high-risk patients earlier than conventional methods, and it is worthy of further large-scale research to determine its clinical application value.

03What do you think is the application value of ctDNA detection in cerebrospinal fluid, this liquid biopsy technology in the diagnosis and treatment of central nervous system lymphoma? At present, its value is not clear, but it can be seen from the clinic that liquid biopsy is an effective supplement to the existing standard detection methods.

First of all, through CSF cfDNA testing, patients who are more likely to have central violations can be detected earlier.
20 of the 67 patients we studied are groups that are at risk of central violations.

Judging from the current research, there is a certain gap between the clinical occurrence of central violations and positive tests.
Which people will appear and which people will not have central violations.
Further observation is still needed, but at least this early diagnosis has been advanced so that we can better Detect special people early.

The second point is that there is another application scenario for cfDNA.
Patients who are diagnosed can be monitored for efficacy through cerebrospinal fluid cfDNA testing.
During treatment, CT cannot understand the efficacy, but cfDNA testing can understand the therapeutic effect.

The third point is that ctDNA testing can help analyze the mechanism of resistance.

For patients with central involvement, the application of cfDNA has the potential to be applied in diagnosis, disease progression monitoring, drug resistance mechanisms, and drug guidance.
Of course, the current preliminary research data still needs more in-depth clinical research for verification.

Professor Wang Xiaoxiao Professor Wang Xiaoxiao’s wonderful video Q1 We learned that you and Shihe Gene have published an article on the clinical value of cerebrospinal fluid ctDNA in predicting early DLBCL central invasion.
Can you introduce the main content of this study? Diffuse large B-cell lymphoma is the most heterogeneous type of lymphoma based on the current WHO classification.
Some patients with diffuse large B lymphoma will have central recurrence or invasion during initial treatment and during treatment.
Conventional methods are like The sensitivity of cerebrospinal fluid flow cytometry or tumor cytology is low, and there is no way to identify high-risk patients, which causes missed diagnosis. The internationally used CNS-IPI scoring method is not very accurate.
Studies have reported that patients with high-risk scores do not have central violations, but low-risk patients have central violations.

Therefore, this is the original purpose of our research.
We hope that the most cutting-edge technology can screen out patients with central infringement at an early stage for more targeted treatment.

02 The five-gene model mentioned in the article is very innovative.
At present, there are many research reports on molecular typing of lymphoma.
Combined with other research reports, what do you think is the significance of the "five-gene model" with central involvement of DLBCL? We first did a correlation analysis on the circulating DNA of the cerebrospinal fluid and the CNS-IPI score, and found that the concentration of circulating tumor DNA in the cerebrospinal fluid was positively correlated with the CNS-IPI score.
The higher the CNS-IPI score, the higher the concentration of circulating DNA in the cerebrospinal fluid of the patient.
high.

We further compared the mutation profiles of these patients with positive cerebrospinal fluid circulating DNA with the identified primary central nervous system lymphoma genes, and screened out 5 high-frequency gene mutations (mutation frequency above 20%) for further follow-up.

So far, 9 CSF-cfDNA-positive patients have experienced central invasion or recurrence during follow-up, and all patients have confirmed 5-gene high-frequency mutations in the CSF; therefore, the “five-gene model” that we first proposed is useful for predicting central invasion.
Clinical reference value. Expert profile: Professor Huang Huiqiang, Deputy Director, Chief Physician, Professor, Doctoral Supervisor, Department of Internal Medicine, Sun Yat-sen University Cancer Center, Chairman of the Lymphoma Professional Committee of the Chinese Elderly Health Care Association, Vice Chairman of the CSCO China Anti-Lymphoma Alliance, and Chairman of the CSCO Thyroid Cancer Professional Committee, China Anti-Lymphoma Vice Chairman of the Lymphoma Professional Committee of the Chinese Anti-Cancer Association Chairman of the Youth Committee of the Lymphoma Professional Committee of the Chinese Anti-Cancer Association Honorary Chairman of the Hematological Oncology Professional Committee of the Guangdong Anti-Cancer Association Deputy Chief Physician, Department of Oncology, Affiliated Tumor Hospital Member of Lymphoma Professional Committee of China Anti-Cancer Association Member of Clinical Chemotherapy Committee of Chinese Anti-Cancer Association Member of Hematological Oncology Professional Committee of Guangdong Anti-Cancer Association Member of Lymphoma Professional Committee of Guangdong Anti-Cancer Association Guangdong Province Member of the Standing Committee of the Hematology Oncology Committee of the Preventive Medicine Association, Deputy Chairman of the Young Physician Branch of the Guangzhou Medical Association, Visiting Scholar GENESEEQ, MD.
Anderson Cancer Center, University of Texas, United States ● Dedicated to tumor precision molecular detection and clinical translational research, and provides hospitals with a Stationary NGS solution ● NGS and liquid biopsy laboratory have obtained three international certifications of CAP/CLIA/ISO15189 and licensed by the Jiangsu Provincial Health Commission ● Serving the clinic for more than 8 years, detecting more than 420,000 tumor samples and more than 200,000 liquid biopsy Example ● Co-published more than 270 SCI papers in total, with a total IF score of over 1700 ● "EGFR/ALK/ROS1/BRAF/KRAS/HER2 gene mutation detection kit" (National Machinery Note 20183400408) as the first batch in September 2018 NGS IVD products are approved for marketing with a sensitivity of up to 1% ● 425 gene TMB kit is the first and only large Panel kit in China to enter the special approval channel for NMPA innovative medical devices ● In September 2020, MERCURY-based multi-omics liquid biopsy technology was launched 15,000 cases of prospective pan-cancer early screening clinical research—Jinling Cohort ● In May 2021, the first domestic prospective multi-center early colorectal cancer ctDNA MRD large-scale study was published *This article is only used to provide scientific information to medical professionals.
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