Research Activities, February 2014
Simulation study evaluates the trade-offs in lifetime risks and benefits of management strategies for ductal carcinoma in situ of the breast
The incidence of ductal carcinoma in situ (DCIS), when cancer remains in the breast duct and has not yet invaded breast tissue, has risen over the past 25 years. Yet, the optimal treatment is uncertain. The study examined six treatment options available to these women: mastectomy with reconstruction, mastectomy without reconstruction, lumpectomy alone, lumpectomy with radiation, lumpectomy with radiation and tamoxifen, lumpectomy with tamoxifen.
The researchers used a disease-simulation model based on published data to determine disease outcomes and treatment tradeoffs for these six treatments. It found that all six treatments had overall survival benefits within 1 year. The model simulated 1 million women receiving a diagnosis of DCIS at 45 years of age. Each woman was considered disease-free after initial treatment and then was considered at risk for a recurrence of cancer in the same breast, the development of a new primary cancer in the other breast, or death from non-breast cancer causes. Those with recurrences would receive a second treatment of a different kind. The lifetime percentage rate of women with native breast preservation was 84 percent for lumpectomy alone and 78 percent for lumpectomy with radiation.
Mastectomy provided the greatest number of disease-free years per patient compared to lumpectomy (9.1 years). The greatest invasive disease-free survival was found for mastectomy and lumpectomy with radiation and tamoxifen. Both yielded an additional 5 years without invasive breast cancer compared to lumpectomy alone. Lumpectomy with radiation and tamoxifen and mastectomy were associated with a 12-month improvement in overall survival compared to lumpectomy alone. When radiation was added to lumpectomy, it only increased survival by 6 months. Out of the 6 treatments, lumpectomy alone had the highest likelihood of death from breast cancer. The lowest likelihood was found for mastectomy and lumpectomy with radiation and tamoxifen.
In the end, women need to understand the tradeoffs of each treatment, its risks and benefits, and how they relate to their own values, suggest the researchers. Their study was supported by AHRQ (Contract No. 290-05-00161).
See "Modeling the effectiveness of initial management strategies for ductal carcinoma in situ," by Djøra I. Soeteman, Ph.D., Natasha K. Stout, Ph.D., Elissa M. Ozanne, Ph.D., and others in the June 5, 2013, Journal of the National Cancer Institute 105(11), pp. 774-781.