13 types of cancer genetic detection technology advantages and prices.

What is a cancer gene? Cancer cells and normal cells, there are many differences, of which, the most important difference is that many of the genes in cancer cells are mutated: some genes are missing, some genes repeated, some genes are long crooked ... Below with the small compilation to understand the various types of cancer genetic detection technology advantages and prices. what is a cancer gene
? There are many types of genetic changes that can occur in cancer.
four main types include: 1) single nucleotide variants (SNV), also known as point mutations.
SNV is produced by base replacement at a base.
these amino acid sequences (wrong mutations) or protein shorter (unrighteous mutations) that may lead to coding proteins.
2) Small replication of continuous nucleotides, involving the insertion or deletion of one or more nucleotides, or complex mutations involving simultaneous deletion and insertion of one or more bases (indelesa).
these types of mutations may be "in-box", resulting in the addition or reduction of amino acids in proteins, or can lead to "shifting", which usually leads to premature shortening of proteins.
3) changes in the number of exons or copies of genes.
changes in the number of exoplanet copies include large repetitions or deletions that contain the entire exon and affect the functional domain of the protein. changes in the number of
gene copies include the amplification or deletion of the entire gene.
4) Structural variation (SV) or large structural abnormalities of genetic material, including translocation or inversion caused by breakpoints between multiple chromosomes or within a single chromosome.
these usually lead to fusion genes and associated fusion proteins.
usually, cancer-causing mutations gather in "hot spot" mutations in tumors from different patients.
some hot spots SNVs may occur frequently, while others are rare.
for example, 40% of all melanomas have BRAF V600E mutations, while BRAF L597S mutations occur. What is cancer genetic testing
? We all know that cancer is a genetic disease that is inextricably linked to genetic mutations that, to some extent, determine the growth and division of cancer cells, and that mutations may be inherited.
can then test the tumor's genetic profile to determine exactly what mutations have occurred, a process called genetic testing.
in the actual treatment process, genetic testing can help doctors develop the best treatment plan.
for example: some people with lung cancer, can use genetic testing methods to test the cancer cells in the EGFR, once found the mutation, can be used to treat the corresponding targeted drugs.
for example, there are some very difficult tumors that need to be identified with specific genetic changes to assist in diagnosis.
for example, many sarcoma are long like a shuttle, long flat, this time if genetic testing found that there is ASPL-TFE3 fusion gene, that diagnosis of adenoid soft tissue sarcoma, it is not far from ten.
use a variety of methods to identify these variants of the gene, careful analysis, can assist in clinical diagnosis, guide treatment choices, assist in the monitoring of disease recurrence and resistance, estimated survival.
tumor genetic testing ranges from simple to complex.
the simplest test to detect only one type of mutation in a gene.
, for example, an experiment to look for specific T-to-A displacement mutations only at BRAF position c.1799.
, the most complex tests can detect all major types of genetic changes at the same time, including replacement, repetition, insertion, deletion, insertion, gene copy number variation and structural variants, including reposition and translocation.
What is targeted therapy based on genetic testing? In the treatment of malignant tumors, a confusing question is: the same stage, the same pathological type of malignant tumor patients, the same treatment plan, the efficacy (such as survival) why there is a significant difference? With the completion of the Human Genome Project, the researchers found that cell molecular biology differences in the same type of tumor may have contributed to the individual differences in disease, and then discovered genes that are closely related to tumor occurrence, the "driven genes" of tumors.
known drivers of lung cancer include EGFR, ALK, KRAS, HER2, BRAF, PIK3CA, AKTI, MEKI, NRAS and MET.
different driving genes, the patient's treatment response to tumor is also different, which is why there is a difference in efficacy of tumor patients with the same type and stage.
at present, some drugs such as targeted drugs have specificity to a certain tumor gene mutation to achieve the effect of precision killing, and different tumor patients tumor-driven gene mutation there are differences, so through genetic testing, to understand which gene the patient has mutation, suitable for which drug, it also achieved the "tailored" effect, to achieve "precision medical treatment."
for example, advanced lung adenocarcinoma patients, more than half of them carry EGFR, ALK, ROS-1 and other genetic mutations, such patients have the opportunity to try targeted drugs, high efficiency, small side effects, relatively long survival.
even some patients rely on a generation of targeted drugs combined with traditional chemotherapy, survival of more than 10 years, 20 years of super lucky cases.
a big contrast between the advantages and disadvantages of various types of cancer genetic detection technology! 1, allele gene-specific PCR advantages: sensitivity - need mutation presence 1-5%.
no special equipment is required.
disadvantage: Target-specificity, inability to detect other mutations that may be present in tumor DNA.
2, Sanger deoxygenation sequencing advantage: various unknown mutations can be detected.
if RNA of fusion transcripts is extracted from the sample for the first time, it can be used to detect gene fusion.
no special equipment is required.
disadvantages: labor intensity, the need for mutant DNA presence 20-25%.
cannot detect changes in the number of exons or gene copies.
3, the advantages of pyrophosphate sequencing: fast and sensitive detection of 5% level of mutant DNA.
disadvantages: the need for pyrophosphate sequencing instruments;
4, the advantages of mass spectrometry: sensitive, 5-10% reliably detect editing mutant DNA;
disadvantages: the need for mass spectrometry instruments; SNV is specific and cannot detect other mutations in the tumor DNA that may exist.
5, single-base expansion determination advantages: sensitive, reliable detection of mutant DNA, if 5-10% present;
no special equipment is required.
disadvantage: SNV is specific and cannot detect other mutations that may be present in tumor DNA.
6, multi-connection-dependent probe amplification-MLPA benefits: fast and simultaneous detection of multiple mutations.
no special equipment is required.
can detect 10% of the target SNV.
disadvantage: For the detection of exon or gene copy number mutation, the mutant DNA needs to exist at a level of 20-40%.
targeted SNV and exosomes and gene copy number variants are specific and cannot detect other mutations in tumor DNA.
kits may not be suitable for genes or mutations of interest.
the detection of fresh frozen tissue is better than that of paraffin-wrapped tissue to extract DNA.
7, fluorescent in situ hybridization-FISH benefits: easy detection of gene copy number changes and targeted SVs, which are not easily detected by other methods;
disadvantages: paraffin wraps are required to bury unstained tissue, and most types of mutations that occur in solid tumortumors cannot be detected.
8, next-generation sequencing-amplification capture benefits: the ability to detect single base replacement and more complex mutations simultaneously, including repetition, insertion, deletion and insertion of missing in many genes in a single assay;
when sequencing to a high "coverage depth" (1000x coverage), assay is sensitive to detecting low abundance mutations.
disadvantages: expensive;
cannot detect gene copy number changes and SV.
9, next-generation sequencing-hybrid capture benefits: the ability to simultaneously detect replacement, repetition, insertion, deletion, insertion and exosome and gene copy changes in many genes in a single assay.
probes can also be designed to capture selective transposition breakpoints in genes that are often rearranged, such as FoundationOne TM.
disadvantages: expensive; require sicodean DNA preparation methods that have traditionally been used for other molecular mutation symostases; require more tumor tissue; and require complex bioinformatics.
10, the next generation of sequencing - full exome group sequencing advantages: comprehensive medium.
in the same test, replacement, repetition, insertion, deletion, insertion, insertion and exon and gene copy changes can be detected simultaneously.
disadvantages: expensive, DNA preparation methods that are completely different from those traditionally used in other molecular mutation detection techniques, more tumor tissue, and complex bioinformatics.
11, next-generation sequencing - whole genome sequencing advantages: the most comprehensive.
can simultaneously detect replacement, repetition, insertion, deletion, insertion, changes in the number of copies of genes and exons, as well as chromosomal inversion and translocation.
disadvantages: expensive and low yields, DNA preparation methods that are completely different from those traditionally used in most mutation detection techniques, more tumor tissue, complex bioinformatics, and huge computational needs for data storage and processing.
12, digital PCR-ddPCR benefits: high levelof sensitivity and specificity;
disadvantages: only known targeted mutations can be detected, limited to detected types of mutations, and only a limited number of mutations can be detected per measurement.
13, BEAMing technology benefits: high sensitivity and specific ity disadvantages: only known targeted mutations can be detected; What samples are
genetic tests done? Genetic testing is to detect mutations in tumor cells, so the need to obtain tumor cells. there are usually three ways
clinically: 1. Get a tumor sample during lung cancer surgery (or chest water).
2. Puncture biopsy samples, usually under local anaesthetic, use very fine needles to pierce suspected tumors to obtain a small number of cells for analysis.
such trauma is minimal, avoiding unnecessary surgery and affecting patients.
3." Liquid biopsy."
a liquid biopsy of lung cancer, mainly by analyzing the blood cancer cells or the DNA released by cancer cells to determine the type of cancer mutation.
this is successful because late-stage cancer cells, or their DNA, often run into the blood, and modern technology can capture them for analysis.
"liquid biopsy" is one of the most popular technology, the biggest advantage is non-invasive, small risk, and can be repeated lying repeatedly, but still with the tissue pathological slice of the genetic test, the highest accuracy, is recognized in the industry gold standard.
although it is not 100% perfect (e.g. there is space, time, heterogeneity).
however, it is often possible to encounter patients who do not have enough tissue, or the tissue specimen is older, in such cases, can also consider using blood samples reluctantly instead.
we generally recommend the best and worse order is: recent surgery or biopsy of newly taken tissue specimens . . . 1-2 years of tissue specimens . . . the latest blood specimens . . . more than 2 years old tissue specimens. How much
cancer genetic test? The price of cancer genetic testing generally depends on the number of sites needed to test, the more the number of tests, the higher the price, the higher the price, the full gene test should be the most expensive, different genetic testing companies, pricing slightly different, but not too much difference.
domestic cancer single-disease genetic testing is generally in 10,000 yuan, the whole gene test about 20,000 yuan, the United States whole gene price slightly higher, 50,000-70,000 yuan.
patients can choose the appropriate type of genetic testing based on economic conditions and type of cancer, and it is recommended to go to a formal genetic testing facility.
Source: Global Oncologists.com/Editor:Ye Bing.