How to make cancer dead in the body? Blood holds the key

by Marta Koblańska, 27.08.2025, 16:47 Poland’s time. Photo: CTC in cancer, Circulating tumor cells in the metastatic cascade (spreading fast), Cancer Cell

Circulating tumor cells in the bloodstream may be crucial for therapies and preventing new metastases in the body. However, success depends on their molecular structure.

Circulating tumor cells (CTCs) are utilized to assess an organism’s overall condition in response to cancer, which may have been previously detected or could potentially be found later in the body. The increasingly common “liquid biopsy” enables the identification of cancer-associated mutations and allows for early detection of cancer, often indicating which organ may be affected.

When the biopsy is performed during ongoing treatment, CTCs can provide valuable information about mutations in the cancer’s genetic makeup that may be linked to drug resistance. This resistance frequently emerges during therapy, but unfortunately, there is no consistent explanation for why it occurs. The troubling aspect of this resistance is that it complicates treatment significantly, and in some cases, it may even render treatment impossible. Consequently, this remains one of the major reasons why many cancer patients continue to die, despite the availability of the latest therapies.

In the study ,,Circulating tumor cells: ,,Blood-based detection, molecular biology, and clinical applications” published in a journal ,,Cancer Cell”, scientists asked some questions on the potential of blood analyses in relation to cancer outcome and diagnosis.

According to scientists, CTCs can contribute to understanding the molecular features, including factors that enable their intravasation, their survival in the bloodstream, and their extravasation to generate distant lesions. Can they also inspire novel therapeutic strategies to suppress cancer metastasis? – ask scientists. If so, can CTCs also be utilized to non-invasively interrogate molecular markers of progression during treatment, improve risk stratification prior to initiating therapy, or even possibly diagnose early cancerous lesions before the development of viable metastases? 

Currently, to get an efficient, let’s say, picture of an overall condition of the body, is prior identification of a tumor or a lethal metastatic presence, which remains a major challenge. How this lethal metastasis hides within an organism still is a mystery, although with some tips. The tip here is the suppression of other lesions through emitted CTCs. (However hardly possible to detect) On the other hand, they (CTCs) could be the way to detect newly acquired changes. How? Ultimately or universally, the answer here could be blood and its components, as well as reactions between them, possibly with tumors derived DNA analysis coming from the blood as well.

Hematogenous dissemination of metastases is mediated by CTCs that travel from the primary tumor to multiple distant organs, where they can establish new cancerous lesions and then spread to additional organ sites

say Charles S. Dai and Daniel A. Haber from Dana-Faber Cancer Institute, Harvard University

The experts admit that a vast number of biological properties of CTS’s are already known; however, due to technological limitations, their clinical promise and, in consequence, utilization may be restricted. Some medics do not like this liquid biopsy because the outcome is not often clear. It is not clear, as to some extent it may be seen as a lottery, why one body has a lethal and non-active tumor, which both drives and suppresses cancer cells’ spread. In addition to getting a reliable outcome, blood volumes for interrogation have to be properly estimated, as the key is to detect those rare cancer cells that contribute significantly to metastases. And this is not so easy, particularly in patients with advanced cancer disease and poor overall condition. Scientists have noted that simpler strategies for DNA sequencing, which use cell-free circulating tumor-derived DNA (ctDNA), have become more clinically useful (and economically feasible- MK) as a form of “liquid biopsy.” This method allows for the identification of cancer-associated mutations that are linked to drug resistance and facilitates the early detection of cancer through DNA-based signatures.

A simplified conclusion could be that the combination of DNA, RNA, and protein analytes derived from intact cells in the blood may allow for a definitive cancer diagnosis in patients without the need for an invasive tissue biopsy. Additionally, this approach could reveal functionally actionable subclonal mutations that might not be detected through single-lesion biopsy-based analysis. Scientists suggest that future applications in early cancer detection and the molecular characterization of minimal residual disease could surpass current analyses based on circulating tumor DNA (ctDNA).

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