Researchers validate recurrence risk test for DCIS
Sunnybrook and ICES researchers and a team of investigators from across Ontario have validated a multi-gene biomarker panel shown to predict the risk of recurrence among patients diagnosed with ductal carcinoma in situ (DCIS) who had breast-conserving surgery treatment alone, as presented today at the 2014 San Antonio Breast Cancer Symposium.
DCIS means that cells that line the milk ducts in the breast have developed cancer features. DCIS is considered non-invasive which means it has not spread through the walls of the milk ducts to surrounding breast tissue, but some DCIS can go on to become invasive cancer. To date, there is no definitive way to know which cases will recur as DCIS or will go on to invasive disease.
Goals of treatment for newly diagnosed women are to reduce the risk of local recurrence and invasive breast cancer, while preserving as much of the breast as possible. Most women will be treated with breast conserving surgery (removes the DCIS part of the breast tissue), usually followed by radiation therapy.
“Currently clinical and pathological features do not reliably help identify individuals at low risk of recurrence after breast-conserving surgery. There is a great need to improve individualized treatment decisions to minimize both under and over treatment for these women,” says Dr. Eileen Rakovitch, lead investigator, radiation oncologist at Sunnybrook Health Sciences Centre and scientist at Sunnybrook Research Institute.
Full media release
RESEARCHERS VALIDATE RECURRENCE RISK TEST FOR DCIS
Toronto, CANADA (December 12, 2014) – Sunnybrook and ICES researchers and a team of investigators from across Ontario have validated a multi-gene biomarker panel shown to predict the risk of recurrence among patients diagnosed with ductal carcinoma in situ (DCIS) who had breast-conserving surgery treatment alone, as presented today at the 2014 San Antonio Breast Cancer Symposium.
DCIS means that cells that line the milk ducts in the breast have developed cancer features. DCIS is considered non-invasive which means it has not spread through the walls of the milk ducts to surrounding breast tissue, but some DCIS can go on to become invasive cancer. To date, there is no definitive way to know which cases will recur as DCIS or will go on to invasive disease.
Goals of treatment for newly diagnosed women are to reduce the risk of local recurrence and invasive breast cancer, while preserving as much of the breast as possible. Most women will be treated with breast conserving surgery (removes the DCIS part of the breast tissue), usually followed by radiation therapy.
The researchers, who are leading work in DCIS, have validated Oncotype DX DCIS Score. The Oncotype DX DCIS score uses a molecular biomarker panel to formulate individualized estimates of 10-year risk of local recurrence in individuals with DCIS treated with breast conserving surgery alone.
“Currently clinical and pathological features do not reliably help identify individuals at low risk of recurrence after breast-conserving surgery. There is a great need to improve individualized treatment decisions to minimize both under and over treatment for these women,” says Dr. Eileen Rakovitch, lead investigator, radiation oncologist at Sunnybrook Health Sciences Centre and scientist at Sunnybrook Research Institute.
The researchers looked at 571 individuals diagnosed with pure DCIS who were treated with breast conserving surgery alone and had negative margins (no cancer cells are seen at the outer edge of the tissue that was removed). With a median follow-up of 9.6 years, the researchers’ report that the DCIS score was associated with local recurrence, regardless of estrogen receptor (ER) status, and provided independent information on local recurrence risk, beyond current clinical and pathologic variables.
Findings show that patients in the low risk DCIS score group had a significantly lower risk of developing a recurrence compared to individuals in the intermediate or high risk DCIS score groups. Every 50 point increase in DCIS was associated with a two-fold increase in the risk of developing recurrence.
DCIS comprises up to 25 per cent of mammographically-detected breast cancers. “It is our hope that this test will provide additional information to physicians and patients, and help guide them in more personalized treatment decisions,” says Dr. Rakovitch, also an adjunct scientist with ICES.
The study was done in collaboration with the Institute for Clinical Evaluative Sciences (ICES). The study was supported by research grants from the Canadian Cancer Society Research Institute, and Genomic Health, Inc.
For more information, please contact:
Natalie Chung-Sayers, 416.480-4040, natalie.chung-sayers@sunnybrook.ca
