Lung cancer drug resistance is detected 5 months early, how is this real-time monitoring of tumor examination done?

We all know that with the application of targeted drugs, drug resistance to lung cancer has become an increasingly common problem.

Many patients have gradually accepted the practice of secondary biopsy after drug resistance, this is because tumor cells are very smart, we use intervention, the initial treatment will kill a large number of tumor cells, but will leave some resistant cells, these cells have changed compared to before treatment, therefore, the need for secondary biopsy to confirm what the mechanism of drug resistance is, so as to develop a reasonable treatment plan.

However, waiting until drug resistance has occurred, and then formulating a follow-up plan through the results of the secondary biopsy, it is somewhat "a bit of a "dead sheep", not to mention that waiting for the results of the secondary biopsy also takes time, which will delay the timing of treatment.

So, is there any way to detect drug resistance earlier than CT tests, tumor markers, etc.? Anti-Cancer Butler - Kang Ai Butler, we fight cancer together, and curing cancer is not a dream. Liquid biopsy is such a visible and tangible "future technology", and studies have shown that liquid biopsy can detect signs of drug resistance up to 5 months earlier.

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What is liquid biopsy?

Liquid biopsy, as the name suggests, is a type of "biopsy". Traditional biopsies are invasive tissue biopsies, which require a traumatic puncture procedure to obtain human tissue.

Liquid biopsy, on the other hand, uses human body fluids as a source of specimens to detect tumor-related information. Liquid biopsy has the following advantages over traditional invasive tissue biopsies:

Effectively overcome tumor heterogeneity: Tumor heterogeneity means that even in the same person, different parts of the tumor are not exactly the same; even for the same part of the tumor, the distribution of different tumor cells is not exactly the same. Anti-Cancer Butler - Kang Ai Butler, we fight cancer together, and curing cancer is not a dream. This leads to a large limitation of tissue biopsy, which can only see the results of the "sampled" site and cannot fully assess the condition of the whole body. Liquid biopsies can overcome this problem to a large extent.

Real-time: Liquid biopsy enables real-time dynamic detection to detect tumor progression earlier.

High compliance: Liquid biopsies are more friendly than tissue biopsies that require traumatic punctures.

Specimens are more accessible: a large part of the specimen is not that they do not want to undergo tissue biopsies, but they do not have the conditions to do it, especially some patients with secondary biopsies, facing the problem of insufficient specimen volume and difficulty in sampling. Liquid biopsies, by contrast, have no drawbacks.

At present, when it comes to liquid biopsy, the main thing is to say that ctDNA (circulating tumor DNA) and CTC (circulating tumor cells) are two types of targets.

ctDNA refers to the DNA fragments in the human blood circulation that carry information such as tumor-specific gene mutations, deletions, insertions, rearrangements, copy number variations and methylation, which are mainly derived from necrotic or apoptosis tumor cells, circulating tumor cells or exosomes secreted by tumor cells.

CTC refers to tumor cells that spontaneously or passively shed from a solid tumor foci and enter the blood circulation. As the "seed" of tumor metastasis/recurrence, CTC carries a wealth of information related to tumorigenesis, development, metastasis, and drug resistance.

Liquid biopsy is used for real-time monitoring

Theoretically, compared with imaging (CT examination, etc.) and serum protein tumor markers (CEA, etc.), ctDNA has better specificity and sensitivity in reflecting efficacy, and can accurately reflect subtle changes in the body's tumor load.

This provides a basis for continuous monitoring of the abundance of ctDNA mutations in tumor patients, and then timely replacement of effective treatment strategies. Anti-Cancer Butler - Kang Ai Butler, we fight cancer together, and curing cancer is not a dream. There are currently small cohort studies that confirm this to be feasible, and continuous monitoring of ctDNA during treatment has found that ctDNA abundance shows a downward trend when the treatment is effective for patients; conversely, ctDNA abundance shows a continuous upward trend when tumors in patients progress.

CTDNA detection can also play an early warning role, and in a variety of solid tumors including lung cancer, colorectal cancer, breast cancer, ctDNA abundance changes occur earlier than imaging findings of recurrence/metastasis.

How far earlier? In one study, researchers analyzed ctDNA from lung cancer patients treated with EGFR-targeted drugs, and liquid biopsy technology detected markers associated with tumor progression and drug resistance 5 months earlier than conventional methods.

Liquid biopsies are used for real-time monitoring of future prospects

Having said so many advantages of liquid biopsy, many people may have questions, "This test is so bullish, how come I haven't seen many people do it?" The reason, of course, is that liquid biopsies are still "very immature" and there are still many problems.

In terms of testing standards, ctDNA testing has defects such as poor reproducibility, poor consistency of test results between different laboratories, low interchangeability of test results between different laboratories, and lack of optimal units for quantifying DNA load, which seriously restricts the application value of ctDNA in clinical practice.

In terms of clinical data, most of the current reports are small sample studies, and there is a lack of large-sample, multicenter, prospectively designed clinical trials.

Therefore, liquid biopsy for real-time monitoring is still in the preclinical stage.

So, is real-time monitoring of liquid biopsies worth doing?

First, liquid biopsies represent the "future." Evaluating the therapeutic effect of patients with non-small cell lung cancer through imaging results is a lagging method, while liquid biopsy can detect tumor information multiple times, in real time, and dynamically. Over time, liquid biopsy has the potential to replace imaging.

Second, at present, liquid biopsy and imaging testing, serum protein tumor marker detection is not contradictory. If possible, fluid biopsy can be performed with one more reference indicator without affecting other treatments.

Finally, liquid biopsies currently provide very limited information and are not routinely recommended. Patients need to consider comprehensively the economic conditions, whether the hospital provides test items, the frequency of tests, whether the individual needs and other issues.

All in all, liquid biopsy technology is an emerging tumor monitoring technology in recent years, with unique advantages and good prospects. It is believed that in the near future, liquid biopsy will more effectively guide and evaluate the treatment of targeted drugs for tumor patients, bringing the gospel to the majority of tumor patients.

This article is transferred from the Lung Cancer Rehabilitation Circle (reprinted and shared by "Anti-Cancer Butler Website - Kangai Butler")