Abstract CN03-03: Improving decision making for ductal carcinoma in situ
Authors: Punglia Rinaa 
Published: October 2015

With greater use of screening mammography, the incidence of pre-invasive breast carcinoma or ductal carcinoma in situ (DCIS) has increased by 560% over the past 35 years. By the year 2020, more than 1 million women will be living with a DCIS diagnosis. Despite the large number of women affected, the optimal treatment strategy for DCIS is not known.

DCIS does not spread to the lymph nodes or other sites in the body, but left untreated, can progress to invasive breast cancer. Mastectomy, or removal of the breast, had been the standard of care for treatment of DCIS and is curative in almost all patients; however, it is an extreme surgery for a diagnosis that may not progress to invasive breast cancer. Currently over 70% of women with DCIS receive breast-conserving surgery, but they then have a risk of being diagnosed with a second cancer in the same breast. To reduce this risk some women receive radiation therapy or tamoxifen therapy. Radiation therapy delivered to the breast after breast-conserving surgery to decrease the risk of another diagnosis in the affected breast. But if a woman undergoes radiation for DCIS and then has a 2nd diagnosis in the same breast, she will need a mastectomy since radiation can only be given once due to limits of normal tissue tolerance. Therefore, radiation therapy may also reduce the long-term likelihood of breast conservation. The important outcome of lifetime breast conservation with or without radiation has not been studied, resulting in patients and physicians choosing treatment without complete information about expected treatment outcomes.

Across the United States, treatment patterns (type of surgery, use of radiation therapy or tamoxifen) for DCIS vary widely by region of the country. Instead, the choice of treatment should vary according to the values and preferences of each DCIS patient. To enable informed decision-making by DCIS patients, we seek to provide individualized data about outcomes– in terms of recurrence, disease-free and overall survival, and likelihood of long-term breast conservation. To present these data, we developed an online decision aid, www.onlineDeCISion.org through support from the Agency for Health Care Research and Quality (AHRQ). This web-based decision aid is informed by a disease simulation model and projects customized 10-year and lifetime outcomes following six different treatment strategies for DCIS: lumpectomy alone, lumpectomy with radiation, lumpectomy with radiation and tamoxifen, lumpectomy with tamoxifen, and mastectomy with and without breast reconstruction (Soeteman et al., JNCI 2013). Presented results are tailored to a patient's age at diagnosis. Default risks of recurrence are taken from randomized trials, however the tool allows for flexibility in terms of presenting outcomes for personalized risks of recurrence.

The development of the decision tool used semi-structured interviews and incorporated results from usability testing with key stakeholders, including a diverse group of multidisciplinary clinicians and patient advocates. After further testing, we hope that our tool will help patients and clinicians choose treatment that is most aligned with a patient's preferences for the tailored outcomes.

Citation Format: Rinaa Punglia. Improving decision making for ductal carcinoma in situ. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr CN03-03.