Molecular diagnostics and personalized medicine company PreludeDx, Laguna Beach, Calif, has recently reported study results demonstrating that its DCISionRT assay can stratify the risk of local recurrence in stage 1 luminal breast cancer patients.The study affirmed that the DCISionRT test is able to stratify patients into low- and high-risk categories.
Patients in the low-risk group had a 4% 10-year risk for local recurrence of either invasive breast cancer or ductal carcinoma in situ (DCIS) when treated with surgery alone, and a 3% risk of local recurrence when treated with surgery and radiation therapy. Patients in the elevated-risk group had a 15% local recurrence risk when treated with surgery alone. After radiation therapy, however, their risk of local recurrence dropped to 3% at 10 years.

According to Rakesh Patel, MD, medical director for breast cancer services at Good Samaritan Hospital, Los Gatos, Calif, the DCISionRT test can help to tailor treatments according to the biologic risk profile of each patient in order to avoid under- and overtreatment.

The study findings are important because the population of stage 1 luminal breast cancer patients over 50 years of age “represents a large share of the patients that we see in clinic, and we currently have very little data guiding us on which patients would truly benefit from conventional adjuvant radiation therapy or, as importantly, if radiation can be more limited or deferred altogether,” says Patel. “Specifically, randomized data have yet to identify patients that do not at least statistically benefit from treatment after a lumpectomy. However, we know that the degree of benefit may not be clinically significant in some patients.”

Likewise, Patel says that patient populations traditionally considered low-risk may have “an elevated risk of developing breast cancer and should be considered for additional treatment such as radiation therapy, tamoxifen, or even chemotherapy.”

“The data presented at ASCO is a great example of how we plan to continue to innovate in this space,” says Daniel Forche, president and CEO of PreludeDx. “We believe it is critically important to offer new radiogenomic tools to radiation oncologists so that they can deliver precision medicine to their patients in an environment where they have an ever-increasing armament of therapies at their disposal.”

PreludeDx was founded in 2009 with technology licensed from the University of California, San Francisco. The company’s DCISionRT test is the only radiogenomic test for assessing risk among patients with DCIS, which affects more than 60,000 women in the United States annually. The test was developed with funding from the National Cancer Institute.

For more information, visit PreludeDx.


  1. Wadsten C, Whitworth PW, Patel R, et al. Risk stratification in early-stage luminal breast cancer patients treated with and without RT [abstract 568]. Poster presented at the annual meeting of the American Society of Clinical Oncology, Chicago, May 31–June 4, 2019. J Clin Oncol. 2019;37(15 suppl);568; doi: 10.1200/jco.2019.37.15_suppl.568.