Q&A

Answer:

1. In terms of sample quality, the quality of recent metastatic samples is superior, and recent metastatic samples should be prioritized.

2. If the patient has received relevant targeted, immunological, or chemotherapeutic treatments from the removal of the primary metastatic tissue to the occurrence of tumor metastasis, then selecting primary metastatic samples for testing may not be appropriate, and metastatic samples should be chosen.

3. If the patient has not received any relevant treatments during this period, both primary and metastatic samples are suitable.

4. For patients with metastases, the interpretation of medication will refer to the primary tumor. 

Answer: In cases where the patient has wax blocks within one year or paraffin sections or wax rolls within six weeks, it is recommended to submit tissue samples for testing. Tumor tissue degradation is more likely to occur in samples over one - year - old, and the success rate of DNA extraction from formalin - fixed paraffin - embedded (FFPE) specimens cannot be ensured. If there is no tumor tissue within one year, the success rate of DNA extraction from FFPE specimens also cannot be guaranteed. For patients in stages III and IV, considering submitting peripheral blood for body fluid testing is a viable option.

Furthermore, if the plasma test result is negative, other types of samples may still be required for verification when necessary. 

Answer: Genetic testing is a technique employed for the detection of nucleic acids (DNA or RNA) from tissues, cells, blood, or other bodily fluids, including saliva, thoracic ascites, and cerebral effusions. It involves extracting the nucleic acid from the subject's sample, amplifying its genetic information, and analyzing the gene type and gene defects it contains, as well as the normality of its expression function, through specific equipment. This is done to comprehend the genetic information of the sample, clarify the cause, or predict the risk of a certain disease in the body. For instance, tumor genetic testing, pharmacogenomic testing,

Answer: When blood is drawn on an empty stomach, it generally has an impact on biochemical indicators, with the most typical being liver function. Nevertheless, for genetic testing, whether the blood is collected on an empty stomach or not does not alter genes. However, excessively high biochemical components in the test will affect the purity of ctDNA extraction.

Answer: Customers with specific requirements can specify them on the application form. The sample types encompass fresh tissue samples, slices, and fresh tissues, and the laboratory will evaluate the tumor cell content.

Under normal conditions, it is advisable that the tumor cell content in tissue specimens tested by next - generation sequencing (NGS) reach over 20%. In the absence of pathological quality control, the proportion of tumor cells may be relatively low, resulting in false negatives. Patients remain willing to undergo NGS testing after being informed.

Reference:

[1] Expert consensus on the application of next-generation sequencing technology in precision medical diagnosis of tumors.