Oncotype DX Test Predicts DCIS Recurrence

Breast Cancer News
January 11, 2012
Michael J. Formica, MS, MA, EdM
Reviewed By: 
Thomas G. Frazier, MD, FACS

Results from a study by the Eastern Cooperative Oncologyinfo-icon Group (ECOG) presented at the 2011 San Antonio Breast Cancer Symposium show an important advance in predicting local recurrenceinfo-icon of ductal carcinoma in situinfo-icon.

The study, part of ECOG’s larger E5194 clinical trialinfo-icon and not yet published in a medical journal, is the first time women at higher risk for local recurrence of DCISinfo-icon could be identified from those at lower risk. This may allow doctors to provide more individualized treatment plans.

Background and Reason for the Study

DCIS, also called ductal carcinoma in situ, is cancer contained in the milk ducts of the breast. In the pathology reportinfo-icon, DCIS is called stageinfo-icon 0 because it has not traveled outside the ducts to the lymphinfo-icon nodes or other areas of the body.

Typically, treatment for DCIS involves lumpectomyinfo-icon, removal of the area of DCIS and a rim of healthy tissueinfo-icon around it, followed by radiation therapyinfo-icon. Both treatments lower the risk of local recurrence, or return of DCIS to the same place. They are also thought to lower the risk for the DCIS returning and becoming invasive, when cancer moves into the ducts and has the ability to travel elsewhere in the body.

Adding radiationinfo-icon to lumpectomy has been shown to greatly reduce the risk of DCIS or invasive cancerinfo-icon returning compared to lumpectomy alone. But if the features of the DCIS suggest it is not likely to recur, forgoing radiation may be a treatment option. Today, this decision is made through a review of the pathology report that accounts for the size of the DCIS area, its gradeinfo-icon, or rate of growth, and margininfo-icon, the rim of healthy tissue.

The E5194 trial originally reported the five-year rates of local recurrence in 670 women who had lumpectomy, without radiation. It showed areas of DCIS of a certain size, grade and margin had low risk of recurrence with lumpectomy alone. Researchers concluded that new methods for more accurately measuring risk of recurrence were needed. They explored this using information from the Oncotype DX assayinfo-icon, a test that looks at the makeup of cancer cells predicting the chances of recurrence in hormoneinfo-icon-positive, early-stage breast cancerinfo-icon that has not traveled to the lymph nodes.

Structure of the Study

Researchers collected the Oncotype DX results from 327 of the women included in the original E5194 clinical trial. Using a new formula, the researchers calculated a DCIS Score to predict the likelihood of cancer returning within 10 years of the initial DCIS diagnosisinfo-icon.

They were testing how well the DCIS Score predicted the recurrence rate for these women to see whether it was a good measure of future recurrence.

Results of the Study

Of the women included in the study, 75 percent were classified low risk, 14 percent intermediate risk and 11 percent high risk. When the DCIS Score was compared to rate of recurrence for these three groups, the researchers found a relationship that was statistically significantinfo-icon, or unlikely to have happened by chance. This suggests the DCIS Score is a good measure of possible recurrence.

What This Means for You

These results show the Oncotype DX DCIS Score may be a tool your doctor can use to predict the chances of DCIS returning. This may allow you to avoid radiation therapy, and impacts your care team’s ability to create a more individualized treatment plan for you.

This test is now available from Genomic Health, producer of the Oncotype DX assay. Ask your care team if the Oncotype DX DCIS Score is something they would consider using in determining the best treatment for you.

Solin, L.J., et. al. A Quantitative Multigene RT-PCR Assay for Predicting Recurrence Risk after Surgical Excisioninfo-icon Alone without Irradiationinfo-icon for Ductal Carcinoma In Situ (DCIS): A Prospectiveinfo-icon Validation Study of the DCIS Score from ECOG E5194. Presented at the 34th Annual San Antonio Breast Cancer Symposium, Abstract S4-6

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Radiation Therapy