When used as a biomarker, microRNAs can help predict which breast cancer patients are more likely to have their cancer return

• MicroRNAs (miRNAs) can serve as a biomarker to predict which patients are likely to face breast cancer recurrence and death
  .
  

• Researchers conducted a multicenter trial in Ireland to take blood samples from 124 breast cancer patients during diagnosis and chemotherapy and evaluated their results
  nearly 9 years later.
  

• The researchers say their findings on the predictive value of miR-145 could help doctors better tailor treatment plans
  for breast cancer patients.
  

CHICAGO: MicroRNA (miRNA) can be used as a biomarker to predict which patients are likely to face breast cancer recurrence and death
, according to findings published online in the Journal of the American College of Surgeons (JACS).

While the long-term prognosis for patients with breast cancer, the most common cancer in women, improves, breast cancer recurs
in 20 to 30 percent of patients.
The process of identifying which patients are more likely to relapse has been a challenge
.
So a team of researchers in Galway, Republic of Ireland, set out to determine whether miRNAs — small noncoding molecules that regulate gene expression and influence cancer development — can predict which breast cancer patients are more likely to recur and die from breast cancer
.

The researchers found that patients with increased expression of certain types of miRNA miR-145 were less likely to have breast cancer
recurrence.
In other words, miR-145 inhibits cancer development and progression, explains lead author Matthew G.
Davey
.

Dr Davey said: "We found that during chemotherapy, the increased expression of this biomarker detected in patients' blood samples can actually predict their long-term tumor prognosis
.
We can predict who is likely to relapse and who will not
.
”

The authors believe that miR-145 can help determine which patients could benefit from
closer breast cancer surveillance and tailored treatment strategies during the postoperative treatment phase.
Similarly, it can identify patients who are at low risk of recurrence and may not need systemic therapy, which often produces harmful side effects
.

"This biomarker will help us deliver the right treatment to the right patients," said
study co-author Michael J.
Kerin.

Study the details

This prospective, multicentre trial enrolled 124 patients
receiving standard care neoadjuvant chemotherapy for localized breast cancer in eight separate treatment sites in Ireland.
The type of chemotherapy depends on the patient's care team
.

Over a three-year period (May 2011 – April 2014), blood samples
from patients were collected at two time points, at the time of diagnosis and in the middle of chemotherapy.
To determine the role of miRNAs in predicting whether patients would not relapse or disease and their overall survival, we assessed miRNA expression levels
at each time point.

Important findings

The study found that an increase in miR-145 expression was associated
with improved outcomes at nearly 9 years of follow-up.

• At statistical analysis, elevated miR-145 independently predicted improvement in relapse-free survival (HR: 0.
  00, 95% CI: 0.
  00 to 0.
  99, P=0.
  050) and a trend towards disease-free survival (HR: 0.
  00, 95% CI: 0.
  00 to 1.
  42, P=0.
  067)

• Elevated expression levels of miR-145 do not predict overall survival
  .
  

Future research opportunities

In the current study, the researchers looked at patients with any of the five breast cancer subtypes, although the study was not designed or supported to determine the effectiveness
of miR-145 in predicting prognosis for any particular breast cancer subtype.
They plan to conduct further clinical trials to help answer this question
.

Professor Kerin said there were also studies underway to see if miRNA expression could be increased
in breast cancer patients.
For example, "a trial is testing miRNA replacement therapy in mice, but the research is still in its early stages, and it's unclear whether this therapy can be transplanted into humans," he said
.

Dr.
David said his team plans to conduct a trial similar to the one they just published in JACS, in which researchers focused on a specific subtype of breast cancer (HER2-positive patients).

valuating the Role of Circulating MicroRNAs in Predicting Long-Term Survival Outcomes in Breast Cancer: A Prospective, Multicenter Clinical Trial