Researchers have discovered that the breast milk of women with breast cancer contains tumor DNA, which could help detect the disease earlier.
- Breast milk from breast cancer patients contains tumor DNA.
- Ultimately, the analysis of breast milk could therefore become a screening technique.
- In France, there were 12,146 deaths in 2018 due to breast cancer, according to Santé Publique France.
Ultimately, this discovery could make it possible to diagnose breast cancer earlier in pregnant women or young mothers. Indeed, in a study published in the journal Cancer Discoveryresearchers observed that the breast milk of breast cancer patients contained tumor DNA, called circulating tumor DNA (ctDNA).
Detect breast cancer earlier
“Patients with breast cancer diagnosed during pregnancy or, especially, during the postpartum period, have a worse prognosis because they are diagnosed at more advanced stages of the disease”, indicates Dr Cristina Saura, author of the study, in a communicated. Physiological changes that occur in the breast during pregnancy and after delivery make tumors more difficult to detect. We also observed that biologically, postpartum tumors are more aggressive.”
Earlier detection of these women is therefore an important issue. So, the researchers wanted to understand if breast milk had traces of the disease. To do this, they analyzed breast milk samples from patients with breast cancer diagnosed during pregnancy or after childbirth, as well as from healthy women who were breastfeeding. At the same time, they also took blood samples from these patients.
Breast milk analysis more reliable than blood for diagnosis
“We found that there was tumor-derived DNA circulating freely in breast milk, explains Dr Ana Vivancos, another author of the study. We were able to detect mutations present in the tumors of breast cancer patients in the breast milk samples of 13 of the 15 patients analyzed. In blood samples collected at the same time, cDNA was detected in only one of them.” In other words, the analysis of breast milk is much more reliable than blood in diagnosing breast cancer.
The scientists therefore conclude that the analysis of breast milk could become an early detection technique for breast cancer in pregnant women and new mothers, during the postpartum period. “This ctDNA can be detected before breast cancer can be diagnosed by conventional imaging“, assures Dr Cristina Saura. However, before the technique is scientifically validated, additional research must be carried out on a wider panel of women.
In France, breast cancer is most common in women. It also represents the leading cause of death from cancer for this sex with, in 2018, 12,146 deaths, according to Public Health France. However, according to the websiteHealth Insurancethere would be a 99% five-year survival rate for breast cancer detected at an early stage compared to only 26% when it is diagnosed at a late stage.
