Predicting the impact of treatment options on survival and breast conservation in patients with ductal carcinoma in situ (DCIS) / Rinaa Punglia.

Format:

Book

Author/Creator:

Punglia, Rinaa, author.

Language:

English

Subjects (All):

Breast--Surgery.

Breast.

Radiotherapy.

Physical Description:

1 online resource (1 PDF file (84 pages)) : illustrations

Other Title:

Predicting the impact of treatment options on survival and breast conservation in patients with ductal carcinoma in situ

Place of Publication:

Washington (DC) : Patient-Centered Outcomes Research Institute (PCORI), 2020.

Summary:

BACKGROUND: Currently, more than 70% of women with ductal carcinoma in situ (DCIS) receive breast-conserving surgery (BCS) but then are at risk of a second cancer diagnosis in the same breast. Radiation therapy (RT) after BCS decreases recurrence in the 10 years after diagnosis by half but does not improve survival. Women with DCIS are also at elevated risk for cancer in the contralateral breast. Radiation after BCS for DCIS limits therapy choice to mastectomy if a woman has a second cancer in the treated breast because radiation can be given only once due to limits of normal tissue tolerance. If radiation was not received initially, a patient may be able to avoid mastectomy after a second ipsilateral breast cancer. For these reasons, the choice of treatment for DCIS is complex. A web-based decision aid would help a patient quantify the tradeoffs between her long-term survival and breast preservation. OBJECTIVES: 1. Determine the risk of and risk factors for new breast cancer after DCIS.2. Determine the likelihood of mastectomy at time of recurrence or new diagnosis after DCIS in a previously unirradiated breast and the association of regional use of RT on this likelihood.3. Determine the tradeoffs associated with RT for DCIS in terms of breast conservation for an individual patient in a web-based decision aid. METHODS: 1. To examine predictors of contralateral breast cancer following DCIS, we identified women diagnosed with DCIS in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. We used multivariable Cox proportional hazards models to examine risks and predictors of contralateral second breast cancer.2. We performed a retrospective analysis of population-based databases SEER and SEER-Medicare. We also measured mastectomy vs BCS at a second breast event (DCIS recurrence or new invasive cancer).3. We developed a discrete event simulation model integrating data from the published literature to simulate the clinical events after 6 treatments for women with newly diagnosed DCIS. RESULTS: 1. In multivariable analysis, age and year of diagnosis, race, size, and estrogen receptor (ER) status were all significant predictors of contralateral breast cancer.2. Residence in a health service area (HSA) with greater radiotherapy use for DCIS was associated with an increased likelihood of receiving mastectomy vs BCS at a subsequent breast event, even among women who had not previously received radiotherapy for DCIS.3. A total of 1 million women of a given age at diagnosis were simulated for each treatment strategy. The model outcomes were disease-free survival, invasive disease- free survival, overall survival, and likelihood of breast preservation over a 10-year and lifetime horizon. The simulation process was automated to create the model output tables for the decision tool. CONCLUSIONS: 1. We demonstrate that DCIS that expresses the ER is associated with a statistically increased risk of having a contralateral breast cancer diagnosis.2. Geographic areas with more radiotherapy use for DCIS had more use of mastectomy at the time of a second breast event even among patients eligible for breast conservation.3. This work culminates in a decision aid that will enable patients and their physicians to choose the treatment most consonant with the patient's history, characteristics, and preferences; it has the potential to improve both quality of life and decision-making for patients diagnosed with DCIS. LIMITATIONS: 1. There may be underascertainment of contralateral breast cancer diagnosis in SEER.2. The SEER database does not capture radiation use and second breast events.3. Although the decision aid aims to help patients and their physicians choose a treatment path based on potential outcomes, it does not consider every possible outcome patients can experience.

Notes:

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