ASCOPost.com | OCTOBER 15, 2013
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Breast Cancer Symposium MRI in DCIS continued from page 12
receive radiotherapy and endocrine therapy, be treated in later calendar years, and had fewer close or positive margins. These findings suggest that oncologists were more likely to order an MRI in women at higher risk and may explain the slightly higher incidence of recurrence in patients who had an MRI, said Dr. Pilewskie.
In an analysis adjusted for patient characteristics and risk factors associated with breast cancer recurrence, use of MRI was not associated with lower 5-year rates of locoregional recurrence or contralateral breast cancer (3.5 years in both groups). At 8 years, the rates of locoregional recurrence were 14.6% for those who had an MRIs 10.2% for those who did not. The 8-year rates of contralateral
Role of MRI in Patients With Ductal Carcinoma In Situ ■■ The study results call into question routine use of perioperative MRI in patients with ductal carcinoma in situ (DCIS).
■■ MRI is expensive and is associated with false-positives, and more judicious use of this technology is warranted in patients with DCIS.
Radiation in DCIS continued from page 12
Study Methods and Results The retrospective study was based on data from 10,468 women diagnosed with DCIS before the age of 75 between 1989 and 2004. Surgery alone was performed in about 71% (43% had mastectomy and the remaining women had lumpectomy), and 28% underwent both surgery and radiotherapy. At a median follow-up of 10 years, compared with the general population in the Netherlands, survivors of DCIS had a similar risk of dying from any cause and a 30% lower risk of dying of cardiovascular disease. Women treated with surgery alone and women treated with surgery and radiotherapy had a similar risk of developing cardiovascular disease: 9% vs 8%, respective-
E. Shelly Hwang, MD on DCIS continued from page 14
sults conflict with those published earlier this year by Darby and colleagues, who found a significantly increased risk for major coronary events from chest wall radiation, which was dose-dependent. This raises the issue of whether the current study may have been underpowered to show a difference between groups.” Other concerns include additional short-term toxicities as well as serious but rare late effects (eg, secondary cancers). Dr. Hwang added, “These [other]
ly. The risk of cardiovascular disease was similar in those who received leftsided radiotherapy (includes a portion of the heart in the radiation field) or right-sided radiotherapy (the heart is not included in the radiation field); in these subgroups, the incidence of cardiovascular disease was 7% vs 8%, respectively. n
Disclosure: Ms. Boekel reported no potential conflicts of interest.
References 1. Boekel NB, Schaapveld M, Gietema JA, et al: Cardiovascular morbidity and mortality in patients treated for ductal carcinoma in situ of the breast. ASCO Breast Cancer Symposium, September 7-9, 2013, San Francisco, CA. Abstract 58. 2. Esserman L, Thompson IM, Reid B. Overdiagnosis and overtreatment in cancer. JAMA. July 29, 2013 (early release online).
morbidities must be considered when administering radiation as part of treatment for a disease which we know has negligible impact on breast cancer mortality.” At this point, there is no way to determine which DCIS will progress to invasive cancer. “Going forward, we will have to redouble our efforts to identify those [patients with] DCIS at highest risk for progression to invasive cancer and to limit treatment for those [patients with] DCIS at lowest risk of progression,” Dr. Hwang said. Work is progressing on identifying
breast cancer were 3.5% and 5.1%, respectively. Lower rates of locoregional recurrence were significantly associated with radiotherapy, endocrine therapy, and margin status, Dr, Pilewskie said.
No Improvement in Outcomes According to Dr. Pilewskie, previous studies indicate that perioperative MRI does not reduce the need for reexcision in women with DCIS. In her opinion, the evidence to date suggests that routine perioperative MRI does not improve either short- or long-term outcomes for patients with DCIS. Dr. Pilewskie said that future research should focus on areas where MRI has the potential to improve outcomes, for
example, in predicting a change in surgical management following neoadjuvant therapy for invasive breast cancer, or in more cost-effective short-sequence MRI screening techniques. n
Disclosure: Dr. Pilewskie reported no potential conflicts of interest.
Reference 1. Pilewskie ML, Olcese C, Eaton A, et al: Association of MRI and locoregional recurrence rates in ductal carcinoma in situ patients treated with or without radiation therapy. 2013 Breast Cancer Symposium, September 7-9, 2013, San Francisco, CA. Abstract 57.
EXPERT POINT OF VIEW
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teven J. O’Day, MD, Director of Clinical Research at the Beverly Hills Cancer Center and Adjunct Member of the John Wayne Cancer Institute in Los Angeles, said, “This is an important study. It allows us to feel comfortable with our aggressive approach to the management of DCIS.” Dr. O’Day moderated the premeeting presscast where this study was presented.
Study Is Reassuring “Screening picks up both invasive and noninvasive cancers. Some patients with DICS will progress to invasive cancer, but we are not sure which patients those are, so we are very aggressive about surgery and radiation if breast-conserving surgery is achieved,” said Dr. O’Day. “There has been concern about the morbidity and mortality related to radiation. Older studies have shown correlations between radiotherapy and cardiovascular disease toxicity when radiation fields overlapped the heart. Although we need to follow this cohort longer, the study is reassuring that with aggressive treatment there is no overall increase in [risk of] death and in particular, no increased risk of cardiovascular death. In fact, there was a slight decrease, which may be due to healthier lifestyle changes adopted by cancer survivors,” Dr. O’Day said. n Disclosure: Dr. O’Day reported no potential conflicts of interest.
See additional expert comments on page 14
both clinical and molecular markers of poor prognosis. “Although there are limitations to any prognostic panel, these predictors have helped to lay the framework to encourage conversations with patients about the tradeoffs between the benefits and morbidities [as well as costs] of treatment. The morbidity of adjuvant treatments remains the same, whether given for low- or high-risk disease. Thus we must continue to question whether the use of radiation can be adequately justified by long-term health benefits in low-risk clinical scenarios,” Dr. Hwang said. n
Disclosure: Dr. Hwang reported no potential conflicts of interest.
References 1. Pilewskie MD, Olcese C, Eaton A, et al: Association of MRI and locoregional recurrence rates in ductal carcinoma in situ patients treated with or without radiation therapy. 2013 Breast Cncer Symposium. Abstract 57. Presented September 7, 2013. 2. Boekel NB, Schaapveld M, Gietma JA, et al: Cardiovascular morbidity and mortality in patients treated for ductal carcinoma in situ of the breast. 2013 Breast Cancer Symposium. Abstract 58. Presented September 7, 2013.