Healthy breast cells can look like invasive cancer, complicating early diagnosis

Be aware, not every cancer diagnosis is as severe as it may seem!

Is it just normal aging or is it cancer?

"Healthy breast cells mimic invasive cancer

Aneuploidy — having too many or too few chromosomes inside a cell — is a hallmark of cancer, but it also affects healthy cells. Genetic sequencing of more than 83,000 breast cells taken from 49 healthy women found that around 3% of their cells were aneuploid — and that these changes to DNA accumulated with age. “This was very unexpected,” says computational biologist and study co-author Nicholas Navin. “We would have classified these cells as having invasive breast cancer based on these [DNA] aberrations.” It is not clear whether aneuploidy in healthy cells is a precursor to breast cancer or not. ..."

From the abstract:

"Aneuploid epithelial cells are common in breast cancer; however, their presence in normal breast tissues is not well understood.

To address this question, we applied single-cell DNA sequencing to profile copy number alterations in 83,206 epithelial cells from the breast tissues of 49 healthy women, and we applied single-cell DNA and assay for transposase-accessible chromatin sequencing co-assays to the samples of 19 women.

Our data show that all women harboured rare aneuploid epithelial cells (median 3.19%) that increased with age. Many aneuploid epithelial cells (median 82.22%) in normal breast tissues underwent clonal expansions and harboured copy number alterations reminiscent of invasive breast cancers (gains of 1q; losses of 10q, 16q and 22q). Co-assay profiling showed that the aneuploid cells were mainly associated with the two luminal epithelial lineages, and spatial mapping showed that they localized in ductal and lobular structures with normal histopathology. Collectively, these data show that even healthy women have clonal expansions of rare aneuploid epithelial cells in their breast tissues."

Nature Briefing: Cancer

Healthy breast cells can look like invasive cancer, complicating early diagnosis "Scientists found that healthy women can carry genetic changes in their breast cells that are thought to be characteristic of invasive breast cancer."

Normal breast tissues harbour rare populations of aneuploid epithelial cells (no public access, but the first article above contains link to PDF file)