Tool Offers Better Measure of Recurrence Risk, Chemo Benefit

When doctors estimate the risk of early-stage hormone receptor-positive, HER2-negative breast cancer that has spread to the lymph nodes coming back (recurrence), they look at a number of the cancer’s features. These include its size, grade, and number of lymph nodes with cancer in them. The age a person is when diagnosed is also considered. Doctors use many of these same factors to decide if chemotherapy would offer more benefits than risks.

More than 20 years ago, the Oncotype DX Breast Recurrence Score Test was developed to help doctors estimate the benefits of chemotherapy, but this test was only for patients with no cancer in the lymph nodes. In 2021, another study showed that the Oncotype DX test also could be useful for people with cancer in the lymph nodes.

Researchers have now developed a new tool, the RSClinN+ Tool, that combines the features of the cancer with results of the Oncotype DX Breast Recurrence Score Test. By combining all these variables into one tool, RSClinN+ offers a more precise recurrence risk estimate than using the cancer features alone or the Oncotype DX Recurrence Score alone, along with a more precise estimate of how much this risk would decrease if that person received chemotherapy along with hormonal therapy after surgery.

The study was published in The Journal of Clinical Oncology.

RSClinN+ is a companion to RSClin, which was released in 2021. RSClin provides similar estimates for people with early-stage hormone receptor-positive, HER2-negative breast cancer that hasn’t spread to the lymph nodes.

The RSClin tools were developed using information from the RxPonder trial and the SWOG-8814 trial. The studies included information from more than 6,000 pre- and post-menopausal women diagnosed with early-stage breast cancer that was hormone-receptor positive and HER2-negative.

To test the accuracy of the tool, the researchers used the RSCliN+ Tool to estimate the recurrence risk and benefits of chemotherapy among 573 people with node-positive breast cancer in the Clalit Health Services registry in Israel. The researchers then compared those estimates to the people’s actual outcomes and found that the RSCliN+ Tool estimates better matched actual outcomes compared to estimates based on Oncotype DX Recurrence Scores alone or cancer features alone.

“Joint patient-physician decision making about chemotherapy [after surgery] requires individualized predictions of absolute… risk and absolute chemotherapy benefit,” said lead author Lajos Pusztai, MD, DPhil, of the Yale Cancer Center, in a statement.

The RSClin tools are available to doctors in the United States, Canada, and Israel.