To order molecular breast cancer testing or not to — that is the question.

To help guide physicians toward the right answer, a free web-based app was developed by a team led by researchers at Johns Hopkins Kimmel Cancer Center.

The app, called Breast Cancer Recurrence Score Estimator, helps predict the benefit of Oncotype DX, which detects gene mutations associated with breast cancer recurrence.

The researchers, including Kimmel Cancer Center members Dr. Antonio Wolff, professor of oncology at Johns Hopkins, Leslie Cope, Ph.D., associate professor of oncology at Johns Hopkins, and Dr. Christopher Umbricht, Ph.D., associate professor of surgery at Johns Hopkins, created the app to help physicians determine whether or not the test will provide new information not found in a patient’s pathology results.

“The starting point was the impression by our medical oncologists that, more often than not, they seemed not surprised by the results of Oncotype DX test results based on the information they already had in the pathology reports,” they said in an email to HCB News.

By using an integrated database at Johns Hopkins that had collected both Oncotype DX results and pathology information, the researchers decided to put that impression to the test.

Medical records of 1,113 patients were used in the development of the Breast Cancer Recurrence Score Estimator, where all the patients had the Oncotype DX test completed and also had stage one or stage two breast cancer that was estrogen-receptor positive. The app would provide a “high risk” or “low risk” result with at least a 95 percent confidence level.

“For undetermined cases, the app does not predict Oncotype DX risk category,” the investigators said. “In such cases, ordering the Oncotype DX test will provide information that is expected to complement pathology information and guide clinicians toward a decision to also recommend chemotherapy or not.”

To use the app, physicians input information from a patient’s pathology report, including levels of a protein called Ki67, which indicates growth rate, the cancer’s grade, the tumor cells’ ability to bind to estrogen and progesterone, and an increase in the HER2 gene, which is known to trigger faster growth of breast cancer cells.

The researchers also wanted to test the outcome of doctors using the app rather than their own intuition when deciding to order the Oncotype DX test or not. By using the app, they would have ordered 297 tests and in reality, 299 tests were ordered.

Genomic Health, the maker of the Oncotype DX test, told HCB News that it found the research interesting but stressed that the Breast Cancer Recurrence Score Estimator is based on factors that are often known to be variable from site to site, and was not directly designed or validated to predict key actual breast cancer outcomes, like chemotherapy benefit.

"Conversely," said the Genomic Health spokesperson, "there is an unprecedented amount of clinical evidence in tens of thousands of patients demonstrating the clinical utility and cost-⁠effectiveness of the standardized Oncotype DX test to accurately inform patient and physician treatment decision-⁠making based on individual tumor biology."

The app may not change the total number of molecular tests ordered at any particular hospital, according to the researchers, but it may shift ordering of the tests to cases where pathology measures are more ambiguous.

“We hope our findings will help clinicians as they strive toward improving patient care and outcomes,” they said.