Researchers at the University of Manchester are investigating whether analysing breast milk could help detect breast cancer earlier. The team is exploring whether fragments of circulating tumour DNA, which may be found in breast milk, can identify the disease sooner than existing approaches such as blood tests or imaging scans.
Although breastfeeding is linked to a lower lifetime risk of breast cancer, the risk is higher during pregnancy and in the months after childbirth. Some women are also more vulnerable at a younger age because they carry inherited genetic mutations that increase their chances of developing the disease.
Urgent need for better detection
Dr Niki Flaum, who is leading the study and is a consultant oncologist at the Christie NHS Foundation Trust in Manchester, said: “There is an urgent need to find better, more reliable ways to detect breast cancer in women during and after pregnancy.
“We believe breast milk may provide a unique and non-invasive window into what is happening inside the breast. We know surprisingly little about the genetic changes to breast milk, as this bio-fluid has been remarkably under-researched until now.
“Pregnancy-related breast cancer is more likely to be diagnosed at a later stage, when the cancer has already spread, and survival outcomes are significantly worse compared with women of the same age who have not recently given birth.
“Diagnosis is particularly challenging because breast imaging during pregnancy and lactation is often unreliable. If reliable methods for detecting cancer-related DNA in breast milk can be found, we hope future research will test whether this approach could be developed into a screening tool for women with breast cancer or those at high risk.”
Scope of the disease
Breast cancer is the most common cancer overall in the UK, accounting for roughly 15% of all new cancer diagnoses. Roughly one in seven women in the UK will develop breast cancer at some point in their lifetime.
Breast cancer is the main cause of cancer deaths in the UK among women aged 35 to 64. Breast cancer linked to pregnancy happens in about one in 3,000 pregnancies, but for women at higher risk, such as those with a faulty BRCA gene, it can be as high as one in 50.
Study recruitment and biobank
The new research, funded by The Christie Charity, is initially recruiting 40 women producing breast milk. This includes 25 with general population risk and 15 from a high-risk category where there is a family history of breast cancer.
The goal is to set up the Manchester Breast Biofluid Biobank with more than 200 samples for future research. The University of Manchester team will analyse the fluid samples at the National Biomarker Centre at The Christie.
One of the first mothers to donate breast milk to the study was Hannah Brennan, 31, from Glossop in Derbyshire. She has a 12-month-old daughter, Ada, as well as a five-year-old daughter and a two-year-old son.
A registered midwife, who is studying for a PhD at the University of Manchester, she said: “As soon as I saw the research team were looking to recruit women who were breastfeeding, I wanted to do it.
“As I’m doing my doctorate, I’m passionate about people being involved in research. My paternal grandmother died aged 51 from breast cancer and sadly I never met her. However, I was named after her and I’m told I look like her so I’m doing this for her as well as my two daughters.
“Participating in the study was really straightforward. I just gave a blood sample and donated some breast milk and answered a few questions. As a midwife I feel it’s really important to help other women, so if my small contribution can benefit other mothers in the future, I’m just glad to be able to make a difference and would encourage other breastfeeding mums to take part.”
Major step forward
Dr Florent Mouliere, who leads the research team analysing samples, said: “Scientists in our laboratories have identified tiny fragments of genetic material shed by cells in some samples of breast milk that have been donated for this study. The DNA structure is unique in breast milk, and we now understand what this DNA looks like, which is a major step forward.”
Louise Hadley, chief executive of The Christie Charity, added: “We are very pleased to be able to fund this important research which could improve early detection of breast cancer in high-risk women, including BRCA carrier, enable screening specifically for pregnancy-related breast cancer and help predict risk of postpartum breast cancer.
“It would also provide reassurance for high-risk women wishing to breastfeed, who are currently often advised to stop early so MRI screening can resume. This support is part of The Christie Charity’s commitment to providing £30 million of much-needed funding by 2030 to enable our brightest researchers to make game-changing discoveries right here in Manchester. We are very grateful for the continued support of all our donors in helping us reach this goal.”
