Abstract P1-10-14: Early results of toxicity for high-risk patients treated with hypofractionated regional nodal irradiation

This abstract was withdrawn by the authors.

P2-16-05: Delay of Adjuvant Chemotherapy after Elective Mastectomy and Immediate Reconstruction in Breast Conservation Candidates: A Matched-Pair Analysis

Background: To analyze factors that influence the timing of adjuvant chemotherapy in patients who are candidates for breast conservation therapy (BCT) but elect mastectomy with immediate reconstruction (M-IR).

Methods: Using data from the University of Louisville Cancer Registry, we identified 35 consecutively-treated patients with stage I or II breast cancer between 2004 and 2009 who underwent M-IR and adjuvant chemotherapy. These were matched for age and AJCC stage to 35 controls who underwent BCT and adjuvant chemotherapy. We examined the timing of initiation of chemotherapy from the date of surgery and assessed the probability of therapeutic delay using univariate logistic regression and McNemar's test for matched pairs. Results: For the 70 patients included in this study, the median age was 46y (range: 30–65y), and the distribution for stage I, IIA and IIB was 22.9%, 65.7% and 11.4%, respectively. The two groups were well balanced in terms of race, rural/urban status, smoking, diabetes, insurance coverage, and histology. The median time to initiation of adjuvant chemotherapy was 38 days (range: 25–103 days) for BCT and 55 days (range: 30–165 days) for M-IR. Patients undergoing M-IR were more likely to experience any delay (> 45 days; 74.3% vs. 25.7%, p < 0.001) and/or significant delay (>90 days; 20.0% vs. 2.9%, p < 0.001) than those choosing BCT. On univariate logistic regression analysis, the extent of surgery had a major impact on the likelihood of any delay in chemotherapy (OR= 8.35, 95% C.I. = 2.86−24.3, p <0.001). None of the other aforementioned factors predicted for delay. Conclusion: The use of elective mastectomy with immediate reconstruction in breast conservation candidates independently predicts for delay in initiation of adjuvant chemotherapy. Further study is needed to qualify the underlying causes of and ultimate clinical significance of these delays.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-16-05.

Long term disease control outcomes for partial breast irradiation using MammoSite brachytherapy

Abstract #5145

Purpose: To describe 4-year local and ipsilateral breast recurrence-free intervals, overall freedom from disease failure, and disease-specific and overall survivals in a cohort of MammoSite Brachytherapy (MBT) patients with mature follow-up, treated at a single institution over a 6-year period.
 Methods and Materials: An analysis of MBT cases was performed using prospectively collected quality assurance database, departmental chart review, and electronic medical records. Patient-, tumor-, treatment-, and outcome-specific data were extracted and recorded into a research database. Eligible patients were required to have >6 months post-MBT follow-up. Local tumor failure was defined as pathologically-proven recurrence within 2 cm of the resected tumor bed, with all other ipsilateral breast recurrences (excluding axilla or internal mammary nodal failures) defined as ipsilateral breast failures. Any local, ipsilateral breast, nodal, or distant failure was censored for overall freedom from failure.
 Results: From 2004 through 2008, 115 MBT patients have been treated, of which 104 were eligible for the present analysis. Median patient age was 62 years (range 25–86). Primary tumors included ductal carcinoma in situ (DCIS) for 20 patients, T1a (12), T1b (31), T1c (34), and T2 (7). Lymph nodes were assessed in 94 patients (including all patients with invasive carcinomas), and revealed pN0 disease in 85 patients, pN1(mic) (3), and pN1a (6). Histologies of invasive carcinomas were ductal in 68 patients, lobular (3), mixed ductal/lobular (3), mucinous/colloid (7), medullary (2), and tubular (1). At a median follow up of 45.7 months (range 7.3-71.4), 6 patients have experienced disease recurrence, including 4 within the ipsilateral breast. Three patients with ipsilateral breast recurrence underwent salvage mastectomy, two of whom remain without evidence of disease recurrence at 56 and 14 months, respectively. Seven patients have died, 3 of or with recurrent breast cancer. Estimated 4-year outcomes for the entire cohort were: local tumor control 100%, ipsilateral breast control 97.0% (95% CI, 93.6%-100%), overall freedom from failure 93.8% (88.5%-99.5%), disease specific survival 97.8% (94.8%-100%) and overall survival 92.7% (87.2%-98.6%).
 Conclusions: The present study demonstrates low rates of local and ipsilateral breast disease failure in a well-defined cohort of MBT patients with mature follow-up.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5145.