Researchers from Canada have reported that women age 44 or younger with ductal carcinoma in situ (DCIS) of the breast have a higher rate of recurrence than older women following breast-conserving surgery and radiation therapy. These results were presented at the ASCO 2009 Breast Cancer Symposium in San Francisco, October 8-10, 2009.

Ductal carcinoma in situ is the earliest possible clinical diagnosis of breast cancer and is frequently diagnosed with screening mammography that has detected small areas of calcification in the breast. Currently, approximately 20% of all breast cancers detected by mammography are DCIS. Patients rarely suspect that they have breast cancer with this stage of cancer.

Treatment of DCIS often involves breast-conserving surgery (lumpectomy) and radiation therapy. A previous randomized EORTC trial showed a 10-year relapse-free survival of 75% for women treated with surgical excision only and 85% for those treated with additional radiotherapy. Factors associated with a risk of relapse were the following: aged 40 years or younger, symptomatic detection, intermediately or poorly-differentiated DCIS, solid or cribiform growth pattern, doubtful margins, and treatment with excision alone. However, researchers at the M. D. Anderson Cancer Center have evaluated the long-term outcome of breast-conservation therapy in patients with DCIS and determined that young age is not an adverse risk factor. This study included 150 women with DCIS treated with surgical excision and radiotherapy between 1980 and 1997. Eight percent of these women had a local recurrence. The probability of a local recurrence was 4% at five years and 12% at 10 years. Recurrences were more frequent for nuclear high-grade lesions, but age had no effect when stratified as less than 40 years versus 40 years or older. Disease control was achieved in all women with recurrences.

To explore outcomes among young women with DCIS, researchers in Ontario conducted a study among women age 50 or younger. Between 1994 and 2003, 1,015 young women were diagnosed with DCIS; 583 of these women were treated with breast-conserving surgery and radiation therapy. Follow-up of these women was a median of 8.5 years.

• Recurrence rates were 20% for women age 40 or younger, 19% for women age 40-44, and 12% for women age 45 to 50. By comparison, recurrence rates for women over age 50 are typically 10-15%.

This study suggests that women under the age of 45 tend to have higher rates of recurrence than older women after treatment of DCIS with breast-conserving surgery and radiation therapy.

In a prepared statement, the lead author of the study noted: “We don’t yet know why younger women with DCIS have a higher rate of recurrence compared with older women. Further research is necessary to determine the causes of this difference and to determine the best treatment for younger women with DCIS. It is important to add that these findings do not imply that all young women with DCIS need to undergo more aggressive surgery, such as a mastectomy, to reduce recurrence risk.”

Comments: Most, but not all, studies have suggested that younger women with DCIS have a higher relapse rate.

Reference: Kong I, Rakovitch E, Taylor C, Nofech-Moses S, Hannah W, Paszat L. Outcomes of young women with DCIS treated with breast-conserving surgery and radiotherapy: A population-based analysis. Presented at the American Society of Clinical Oncology (ASCO) 2009 Breast Cancer Symposium. Abstract 127.