Breast Cancer Recurrence at Higher Rate for Young Women With DCIS

Women 44 years and younger with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and radiation have almost double the risk of recurrence than women ages 45 and older, finds a Sunnybrook-led, population-based Canadian study of a large DCIS cohort of 5,744 women in Ontario. The study cohort was made up of 624 younger women with DCIS who were treated with breast-conserving surgery and radiation, and the results will be presented at the ASCO (American Society of Clinical Oncology) Breast Cancer Symposium (Merit Award study).

"Our findings show higher recurrence in younger women treated with breast conserving surgery and radiation. Further research is needed to determine why younger women have higher recurrence rates and determine optimal treatment strategies to balance effective therapies with quality of life - treatment approaches such as adjuvant ‘boost' radiation therapy or systemic therapy with tamoxifen need to be further evaluated," says Dr. Iwa Kong, breast oncology research fellow and lead author, who conducted the study under the supervision of Drs. Eileen Rakovitch and Lawrence Paszat, at Sunnybrook's Odette Cancer Centre and the Institute of Clinical Evaluative Sciences.

"With increased screening mammography, ductal carcinoma in situ (DCIS) represents 25 per cent of new cases of breast cancer. Every oncologist is likely seeing a percentage of these patients and yet optimal treatment for patients 50 years or younger is less clear," says Dr. Kong, a University of Toronto, Department of Radiation Oncology fellow.

Sunnybrook researchers examined the rate of local breast tumour and local invasive breast cancer recurrence in 624 women 50 years and younger diagnosed with DCIS from 1994 to 2003 in Ontario, who had breast-conserving surgery (lumpectomy) and radiation. After a median follow-up period of 7.8 years, the rate of recurrence among women ages 44 years or younger was significantly higher at 20 per cent, compared to 12 per cent among women 45 years and older. The typical recurrence rate among women 50 years and older treated with lumpectomy and radiation is 10 per cent at 10 years, from randomized studies in the literature.

This study was generously funded by the Canadian Cancer Society Research Institute.