Faculty Bibliography

BACKGROUND AND PURPOSE: We evaluated the effect of post-mastectomy radiation (PMRT) in 1-3 positive lymph nodes (LN) in patients who received uniform modern systemic therapy. MATERIALS AND METHODS: Cohort study using individual data collected for 1,649 node-positive women who received doxorubicin/cyclophosphamide with sequential docetaxel in 2000-2003 on the control arm of BCIRG-005. All women underwent mastectomy or lumpectomy and axillary LN dissection. PMRT was given at investigator's discretion. RESULTS: A total of 523 women with 1-3 positive LN underwent mastectomy and 39% (206/523) received PMRT. With a median follow-up of 10years, PMRT improved loco-regional control (LRC) from 91% to 98% (p=0.001) but had no effect on overall survival (OS) (84% vs. 86%, p=0.9). On multivariate analysis, PMRT improved local control (LC) (hazard ratio, 0.14; 95% CI, 0.03-0.62; p=0.01) and LRC (hazard ratio, 0.15; 95% CI, 0.04-0.50; p=0.002). PMRT did not significantly impact OS on multivariate analysis (hazard ratio, 0.91; 95% CI, 0.55-1.51; p=0.7). Results remained consistent with the use of propensity score analysis. CONCLUSIONS: In this cohort of patients with N1 disease treated with modern systemic therapy, PMRT improves LRC but has no effect on OS. The rates of OS were excellent, irrespective of adjuvant radiation.

Background/Objective: In a time when clinicians are attempting to identify a cohort of patients with ductal carcinoma in situ (DCIS) who will benefit most from post-lumpectomy radiation therapy (RT), tools have been developed to quantify patients' risk for in-breast recurrence. These tools have not yet been integrated into standard use. At our institution, the recommendation for RT after lumpectomy for DCIS is guided by established clinicopathologic factors and reviewed by a multi-disciplinary group. The purpose of this study was to compare the clinicopathologic characteristics and outcomes of postlumpectomy DCIS patients with and without RT at our institution. Methods: The Institutional Breast Cancer Database was queried for all women who were diagnosed with DCIS from 2010-2016. Variables included age, method of presentation, risk factors, tumor and treatment characteristics, and ipsilateral breast tumor recurrence (IBTR). Statistical analyses included Pearson's Chi Square and Fisher's Exact Tests. Results: Of 480 women with pure DCIS and no prior history of breast cancer, 350 (73%) underwent lumpectomy. The median follow-up was 4 years, and median age was 60 years. Two hundred thirty-six (67%) women underwent RT following lumpectomy. Compared to women who did not undergo RT, these women were younger (p=0.003), had larger tumor size (p=0.0008), higher grade (p=0.0006), and comedo features (p=0.03). Women who underwent post-lumpectomy RT had an IBTR rate of 2% vs. 4% (p=0.32) with no RT. The 10 patients with early IBTR in both groups were younger (median age 54 years), and all had intermediate- or high-grade DCIS. Of the 114 patients who did not undergo adjuvant RT, 70 (61%) met the RTOG 9804 criteria for omission of adjuvant RT. Of the 44 patients who did not receive adjuvant RT and did not meet RTOG 9804 criteria, 20 declined RT, and 24 were not referred. Conclusions: Within a relatively short follow-up period, we found a very low overall rate (3%) of IBTR for our patients who underwent lumpectomy for DCIS. These results are consistent with previously published trials on post-lumpectomy RT in DCIS. RT at our institution is recommended based on wellestablished clinicopathologic factors and multidisciplinary care. Considering the low recurrence rates, we recommend continuing the current trend of using published criteria and multidisciplinary review. It remains to be seen to what extent the newly developed recurrence tools, such as Oncotype DX Breast DCIS ScoreTM, will improve upon these short-term recurrence rates

Introduction: The treatment of ductal carcinoma in situ (DCIS) remains controversial, and treatment approaches include surgery, post-lumpectomy radiation therapy (RT), and/or hormonal therapy for prevention of recurrent disease. These decisions may be particularly difficult for patients with minimal disease. There is a dearth of information regarding patients who have been diagnosed with DCIS on core-needle biopsy (CNB) who have no residual disease in the area at surgery. The purpose of this study was to explore the frequency of this presentation and short-term outcomes in these patients. Methods: Our institutional Breast Cancer Database was queried for all women who were diagnosed with pure DCIS from 2010-2016. Variables included age, method of presentation, risk factors, tumor characteristics and outcomes. Statistical analyses included Pearson's Chi Square and Fisher's Exact Tests. Results: Out of a total of 548 patients with pure DCIS, 55 (10%) had DCIS on CNB alone with no residual in the surgical specimen. The median age was 55 years (range 36-83). Of the patients with DCIS on CNB alone, 6 (11%) were treated with mastectomies. 14 (25%) had lumpectomy and RT, while 35 (64%) had lumpectomy without RT. The median follow up was 4 years. There were three ipsilateral recurrences in women who were treated by lumpectomy alone. One of these recurrences was invasive carcinoma, and the other two were recurrent pure DCIS. None of the patients who recurred had taken hormonal therapy. There were no contralateral second primaries detected in the study period in this cohort. Conclusions: Despite the minimal extent of disease exhibited in these cases, 3 of 35 patients with DCIS on CNB with no residual disease at surgery and no RT had ipsilateral recurrence at a median follow up of 4 years. These data suggest that even minimal DCIS represents a significant risk of recurrence to the patient. Additional information provided by genomic analysis may better stratify the risk for recurrence in this group and help identify the population that would most benefit from post-lumpectomy RT