New Delhi: A new cancer diagnostic test developed by researchers from the University of North Carolina School of Medicine accurately predicts whether breast cancer patients need chemotherapy, or if hormone therapy alone would be a safe and effective treatment plan.
“Support from a new clinical trial has found that more than two-thirds of high-risk patients could be spared chemotherapy without compromising outcomes,” said Charles Perou, distinguished professor at the UNC School of Medicine and one of the researchers who developed the diagnostic test.
According to the statement posted on the university’s website, Perou’s work was critical in the development of the diagnostic test, called Prosigna. In 2005, researchers started working on a genomic test that can identify the patient’s breast cancer subtype and estimate the probability of the cancer coming back. This test can be used in the clinic and does not require an elaborate arrangement.
How does the test work?
According to the UNC School of Medicine, Prosigna analyses tumour samples and uses a machine learning algorithm to assess an ROR–risk of recurrence–score for the patient, which provides oncologists an insight into the patient’s disease progression. These details include the probability of a patient’s risk of cancer relapse.
In 2007, a clinical trial was set up to see if the Prosigna test could safely guide chemotherapy decisions for patients with early-stage, ER-positive HER2-negative breast cancer.
In this type of breast cancer, the tumour cells have ER or estrogen receptors, that use the hormone estrogen to grow. However, they do not have high levels of the HER2 or the human epidermal growth factor receptor-2, a protein which controls how healthy cells grow, divide, and repair. The ER-positive HER2-negative breast cancer is also the most common subtype of breast cancer, representing about 70% of all cases.
The university’s statement said that the trial —Optimal Personalised Treatment of early breast cancer using Multi-parameter Analysis (OPTIMA)— was followed with more than 4,400 patients across the UK, Norway, Sweden, Australia, New Zealand and Thailand for over 20 years.
“Participants were put on a treatment path according to their Prosigna results. Those who received high ROR scores (>60) received chemotherapy followed by hormone therapy, while those with low ROR scores (≤60) received hormone therapy alone,” the statement read.
The results
The most promising outcome of the study was that over 68% of patients with clinically high-risk breast cancer could safely forgo chemotherapy entirely.
“These patients achieved five-year cancer-free survival rates of 93.7% without chemotherapy, demonstrating that omitting treatment did not compromise overall health outcomes or increase cancer recurrence risk,” according to researchers.
The findings also showed that the Prosigna test was “equally effective for previously under-studied populations (premenopausal women and those with multiple breast cancer containing lymph nodes) demonstrating that assessing tumor biology, versus clinical factors alone, can guide chemotherapy decisions for more complex cases.”
(Edited by Aakriti Handa)