New Test Provides More Complete Picture of Recurrence Risk for DCIS

Lawrence J. Solin, MD

A new test specifically designed for breast cancer patients with ductal carcinoma in situ (DCIS) appears to be a better indicator of recurrence than other assays for more invasive forms of the disease.

Now that a validated test is available to predict recurrence in DCIS, it is important for physicians to apply it to clinical practice to help determine treatment of patients with this less invasive form of cancer.

Lawrence J. Solin, MD, chairman of Radiation Oncology at Albert Einstein Medical Center in Philadelphia, Pennsylvania, presented data on the DCIS score at the 9th Annual Northern New Jersey Breast Cancer Conference, held at the John Theurer Cancer Center.

Solin explained that due to the increased use of screening mammography, DCIS is a common diagnosis. However, because it is not clear which patients will experience recurrence, many patients are treated with radiation. The new test, developed by Genomic Health, can be used to identify low-risk patients who do not require further radiation, as well as highrisk patients who should be treated more aggressively.

Solin first presented results of a trial assessing this new DCIS score at the San Antonio Breast Cancer Symposium in December. Solin was one of the authors of a validation study that was based on tumor samples from 327 patients enrolled in ECOG 5194, a multi-institutional study of patients with low-, intermediate-, or high-grade DCIS who had been treated with breast conservation, had wide negative margins, and did not receive any radiation treatment.

The DCIS score uses a 12-gene assay, and according to the results presented at SABCS, the score was a highly significant and strong predictor of local recurrence (P = .02) and invasive local recurrence (P = .01) over a 10-year period.

“The idea is to identify patients who don’t need radiotherapy for this particular form of noninvasive breast cancer,” Solin said.

Based on the study, Solin said that the most appropriate clinical use is for postmenopausal patients over the age of 50, since younger patients diagnosed with DCIS are already at a higher risk of experiencing local recurrence or local invasive recurrence. However, Solin said that clinical parameters previously established for treating patients with DCIS should be included rather than ignored, based on the results of this assay.

A DCIS score could affect a number of treatment approaches, such as radiation therapy or surgery. However, Solin said that the use of tamoxifen in DCIS patients is an independent variable, and that nothing from the ECOG 5194 study contradicted guidelines or clinical trials regarding the use of tamoxifen in these patients. Tamoxifen is not used to treat DCIS itself, but rather is given as adjuvant therapy to prevent recurrence.

Because many practices are already familiar with ordering the OncotypeDX Breast Cancer test, implementation of this DCIS test should not prove difficult, said Solin. However, all treatment teams that meet with a DCIS patient need to communicate with one another in order for the test to be properly used across the board, he said.

“The surgical oncology colleagues will need to be much more attuned to this in terms of talking to patients and discussing with patients, and perhaps beginning the test prior to radiation oncology consultation or concurrent with a radiation oncology consultation,” Solin said.