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Artificial Intelligence in Health AI in early breast cancer diagnosis: A review

2.3. Cancer biomarkers obtained from liquid biopsy necrotic tumor cells. When derived from tumors, it is
(LB) known as circulating tumor DNA (ctDNA). CtDNA can
LB is emerging as a revolutionary, non-invasive technique carry mutations, copy number variations, and methylation
for the timely diagnosis and management of breast changes characteristic of cancer. Using high-throughput
cancer. Unlike traditional tissue biopsies, liquid biopsies sequencing technologies, these genetic alterations can
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analyze biomarkers found in body fluids such as blood, be detected and monitored over time. CtDNA analysis
urine, or saliva. This method holds significant potential is particularly valuable for detecting minimal residual
for expediting early detection, monitoring treatment disease and monitoring treatment responses, providing a
responses, and understanding the molecular dynamics dynamic picture of the tumor’s genetic profile. 14
of breast cancer. LB involves detecting the presence and MicroRNAs, as the name implies, are small RNA
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molecular analysis of CTCs, cell-free DNA (cfDNA), molecules involved in the regulation of gene expression.
and other biomolecules such as proteins and miRNAs in Certain miRNAs are expressed in cancer patients and
the blood. These components are shed from the primary can serve as biomarkers for early detection. In addition,
tumor into the bloodstream, providing real-time insights protein biomarkers, such as cancer antigen 15-3 and
into the genetic origins of cancer. Figure 2 illustrates these carcinoembryonic antigen, are often found in elevated
biomarkers and their origins. levels in breast cancer patients and can be detected
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Circulating tumor cells are cellular remnants of cancer through blood tests. The combined analysis of miRNAs
cells that have sloughed off the main tumor or cancer sites and protein biomarkers can enhance the sensitivity and
and enter the bloodstream. Although they are relatively specificity of liquid biopsies.
rare, with only a few CTCs found among millions of blood LB requires only a blood draw, which reduces the
cells, their presence provides crucial information about discomfort and risks associated with traditional tissue
the tumor’s characteristics and potential for metastasis. biopsies. This technique can detect cancer-related genetic
Techniques such as immunomagnetic separation and alterations before they manifest as clinical symptoms or
microfluidic devices are employed to isolate and analyze become visible on imaging, enabling earlier intervention.
CTCs. Identifying and characterizing CTCs can help Furthermore, LB allows for continuous monitoring of
detect the initial stage of breast cancer and predict tumor dynamics, helping to assess treatment efficacy and
metastasis. 13 detect resistance. Multiple biomarkers can be analyzed
Cell-free DNA refers to circulating DNA fragments simultaneously, providing a comprehensive view of the
released into the bloodstream, often from apoptotic or tumor’s genetic and molecular landscape.

Figure 2. Different components of liquid biopsies for the early detection of breast cancer

Volume 2 Issue 2 (2025) 104 doi: 10.36922/aih.4197