Low-cost tests can identify breast cancer patients at high risk of recurrence

Breast cancer cells. credit: Ewa Krawczyk, National Cancer Institute

Testing women’s response to hormone therapy for breast cancer before and after surgery may be a quick and inexpensive way to predict the likelihood of recurrence of the disease, major clinical trials say. discovered.

Researchers are testing to measure how the growth rate of cancer cells changes two weeks after starting a type of treatment. Hormone therapy It strongly indicated whether women’s cancer is likely to recur.

Testing can provide peace of mind for Female Standard treatment may work — often only subsequent hormone therapy Surgery And radiation therapy — and may identify people at high risk of recurrence and offer additional treatment or admission opportunities Clinical trial..

Studying the Benefits of Preoperative Hormone Therapy

The results of large clinical trials provide conclusive evidence of the benefits of testing the response to a drug called. Aromatase inhibitorSuppressing estrogen levels — to guide treatment decisions for women after surgery.

Results of the POETIC trial published in Lancet oncology And funded by Cancer Research UK, it has the potential to change the clinical practice of the NHS in the future.

A team from the Institute of Cancer Research in London and the Royal Marsden NHS Foundation Trust studied 4,480 early-stage hormone-positive women. breast cancerTwo-thirds received letrozole or anastrozole, one of the aromatase inhibitors, two weeks before and after surgery.

The remaining women underwent surgery and received aromatase inhibitors at normal times. Only after surgery. All women were recommended to continue hormone therapy for at least 5 years as part of standard treatment.

Most women who are positive for hormone receptors milk Cancer receives hormone therapy such as aromatase inhibitors for 5 years. This helps reduce the risk of breast cancer recurrence.

The POETIC trial investigated whether aromatase inhibitors could be further reduced by giving them two weeks before surgery rather than starting them after surgery.

How Ki67 changes affect the risk of recurrence

It was also aimed at assessing the value of markers of cancer cell growth to predict female response to aromatase inhibitors.

The researchers compared levels of a protein called Ki67 in tumor samples taken two weeks after starting treatment with an aromatase inhibitor when the woman was first diagnosed.

In women who received aromatase inhibitors prior to surgery, researchers were able to analyze how changes in Ki67 affected the risk of cancer recurrence. They found that only 4% of women in this group, whose Ki67 levels were initially low and remained low after the start of treatment, had a recurrence of breast cancer 5 years after surgery.

Of the women who started with high Ki67, 22% of women who remained high Ki67 after the start of treatment compared to 8% of women whose tumor samples showed low Ki67 levels after 2 weeks of treatment. , The cancer has recurred within 5 years.

Research provides peace of mind

The study found no significant change in the risk of cancer recurrence in women, whether or not they were given an aromatase inhibitor two weeks before surgery.

Despite the results that do not show reduced risk, this finding is important because it means that women can safely start aromatase inhibitors immediately after being diagnosed with early-stage breast cancer. This has proven to be particularly beneficial during the COVID-19 pandemic. There was a delay in surgery.

This result is the most powerful to date about the value of giving women a short course of aromatase inhibitors before and after surgery, in combination with the relatively inexpensive tests needed to measure Ki67 levels in tumor samples. Providing proof.

Researchers believe that Ki67-level measurements are much cheaper than other gene-based tests for assessing therapeutic response, making it easy to incorporate their tests into NHS’s day-to-day operations. I will.

Choose patients at high risk

Professor Judith Bliss, director of the clinical trials and statistics unit funded by Cancer Research UK at ICR, co-leader of the study, said:

“Our study suggests that many women with early-stage hormone-positive breast cancer should be offered treatment with aromatase inhibitors before and after surgery. Aromatase inhibitors are high-risk patients There is also an important benefit of helping to find out. Their cancer has recurred.

“Measuring the growth response of cancer cells to aromatase inhibitors, instead of more expensive genetic testing, is a low-cost way to select women who are likely to succeed with standard treatment or who should consider clinical trials. It may be a method, and aromatase inhibitors are a well-established treatment, so testing should be relatively easy for standard practice with NHS. “

“Cheap and easy”

Ian Smith, a senior researcher and consultant medical oncologist at Royal Marsden and an emeritus professor of cancer medicine at ICR, said:

“This important trial is the largest in the world and enrolled approximately 4,500 patients in 130 NHS breast units across the UK. Patients with early-stage breast cancer received a two-week simple endocrine therapy with aromatase inhibitor tablets. It has shown that it can be done preoperatively, especially to help identify which patients can avoid unpleasant toxic chemotherapy. This test is much cheaper and easier than current genomic tests. And we believe it should be part of Standard treatment For early breast cancer. “

Professor Arnie Purushotham, Senior Clinical Adviser at Cancer Research UK, said:

“Unfortunately, breast cancer can come back in some women, so a new way to predict if the cancer will come back means that doctors can monitor these patients more closely. Survival. To improve the rate, it is important to detect signs of cancer as soon as possible, and it also affects how doctors decide to treat early-stage hormone-positive breast cancer. There is a possibility of triaging women accordingly. cancer Come back. ”