Recent research suggests that our current methods for classifying cancer and detecting it in its early stages may need to be reevaluated. Even healthy women have been found to carry cells with characteristics commonly seen in breast cancer.
These cells, known as aneuploid cells, have an abnormal number of chromosomes. A common feature in invasive breast cancer, these cells are believed to aid in the spread of cancer and evasion of the body’s immune system.
Interestingly, aneuploid cells may also be present in individuals without any signs of cancer. A study conducted by researchers from the University of Texas and Baylor College of Medicine in Texas discovered these cells in breast tissue samples from 49 healthy women.
“Traditionally, we have believed that normal cells have 23 pairs of chromosomes. However, our study revealed irregularities in every healthy woman we analyzed, posing a thought-provoking question about the onset of cancer,” stated biologist Nicholas Navin from the MD Anderson Cancer Center at the University of Texas.
Navin added, “Based on genomic characteristics, a cancer researcher or oncologist would classify these normal breast tissue cells as invasive breast cancer.”
Through techniques like single-cell sequencing, the research team identified signs of aneuploidy present in approximately three percent of the total breast epithelial cells analyzed in each woman. Epithelial cells, found lining the body internally and externally, are believed to be the starting point for cancer development.
The study revealed that most aneuploid cells exhibited copy number alterations, where DNA segments are duplicated or deleted. These alterations are believed to play a crucial role in cancer progression.
Interestingly, the researchers found that the presence of these cellular changes increased with age among the women. The most frequent alterations observed, such as extra copies of the 1q chromosome and missing 10q, 16q, and 22 chromosomes, are also characteristic of breast cancer.
Notably, aneuploid cells were predominantly found in two types of breast cell lineages responsible for secreting milk: Luminal Hormone Receptor-Positive (LumHR) and Luminal Secretory (LumSec). This suggests that different forms of breast cancer may develop from distinct lineages.
The implications of these findings are still unclear, posing questions about the appearance of normal, healthy tissue, methods for preventing false positives, and the risk factors determining whether aneuploid cells progress to cancerous states.
“This discovery has significant implications not only for breast cancer research but potentially for various cancer types,” suggested Navin.
Navin added, “This doesn’t necessarily imply that everyone harbors precancerous cells, but it does call for broader studies to comprehend the implications for cancer development.”
The researchers believe that their approach could uncover aneuploid cells in other body parts and provide insights into the initiation of various types of cancer.
“Future investigations in this field are likely to yield new perspectives on cancer onset and address the fundamental question of cancer development,” noted the researchers in their published paper.
The research findings are outlined in a publication in Nature.
