Breast Conserving Therapy for Patients With Prior Cosmetic Implant-Based Breast Augmentation: Outcomes and Comparison Against a Matched Cohort.

INTRODUCTION: Controversy exists regarding potential increased toxic effects in patients with cosmetic implant-based augmentation (CIBA) who receive radiation therapy. We evaluated acute and chronic toxic effects associated with radiation therapy in women with prior CIBA treated with whole-breast irradiation (WBI) as part of breast conserving therapy (BCT) and compared these results against a cohort of patients without prior breast augmentation who received similar therapy. METHODS: A retrospective review was performed to identify patients with a prior history of CIBA who subsequently underwent BCT with WBI. The control group consisted of consecutively treated patients without prior CIBA who also underwent BCT with WBI. Analyses included a comparison of baseline and treatment-associated factors between the augmentation and control groups, evaluation of toxic effects between both groups, and multivariable analysis of factors associated with the receipt of additional surgery following radiation. RESULTS: Thirty-six patients with prior CIBA and 135 consecutively treated patients without CIBA were identified. Patients with prior CIBA were treated from 2006 through 2019, and patients without CIBA were treated from 2016 through 2019, though treatment characteristics and median follow-up time were similar between the two groups. Patients with prior CIBA were significantly less likely to experience acute moist desquamation (0% vs. 18%; P = .005). There were otherwise no statistically significant differences in acute (≤ 6 months) or chronic (> 6 months) toxic effects between the two groups. Rates of excellent/good chronic cosmetic outcome were 89% for the CIBA group and 97% in the control group (P = .094). On multivariable analysis, patients without prior CIBA (OR = 0.04; CI = 0.01-0.13; P < .001) and patients treated with moderately hypofractionated irradiation (OR = 0.08; CI = 0.02-0.23; P < .001) were significantly less likely to undergo additional surgery following receipt of WBI. Two patients experienced implant loss following radiation therapy. CONCLUSIONS: WBI as part of BCT in patients with prior implant-based breast augmentation appears safe and is associated with favorable cosmetic outcomes. There was an increased need for additional surgery in patients with prior CIBA, but rates of acute and chronic toxic effects appeared similar to those in nonaugmented patients.

A Three-Dimensional Bioabsorbable Tissue Marker for Volume Replacement and Radiation Planning: A Multicenter Study of Surgical and Patient-Reported Outcomes for 818 Patients with Breast Cancer.

BACKGROUND: Accurate identification of the tumor bed after breast-conserving surgery (BCS) ensures appropriate radiation to the tumor bed while minimizing normal tissue exposure. The BioZorb® three-dimensional (3D) bioabsorbable tissue marker provides a reliable target for radiation therapy (RT) planning and follow-up evaluation while serving as a scaffold to maintain breast contour. METHODS: After informed consent, 818 patients (826 breasts) implanted with the BioZorb® at 14 U.S. sites were enrolled in a national registry. All the patients were prospectively followed with the BioZorb® implant after BCS. The data collected at 3, 6, 12, and 24 months included all demographics, treatment parameters, and provider/patient-assessed cosmesis. RESULTS: The median follow-up period was 18.2 months (range, 0.2-53.4 months). The 30-day breast infection rate was 0.5 % of the patients (n = 4), and re-excision was performed for 8.1 % of the patients (n = 66), whereas 2.6 % of the patients (n = 21) underwent mastectomy. Two patients (0.2 %) had local recurrence. The patient-reported cosmetic outcomes at 6, 12, and 24 months were rated as good-to-excellent by 92.4 %, 90.6 %, and 87.3 % of the patients, respectively and similarly by the surgeons. The radiation oncologists reported planning of target volume (PTV) reduction for 46.2 % of the patients receiving radiation boost, with PTV reduction most commonly estimated at 30 %. CONCLUSIONS: This report describes the first large multicenter study of 818 patients implanted with the BioZorb® tissue marker during BCS. Radiation oncologists found that the device yielded reduced PTVs and that both the patients and the surgeons reported good-to-excellent long-term cosmetic outcomes, with low adverse effects. The BioZorb® 3D tissue marker is a safe adjunct to BCS and may add benefits for both surgeons and radiation oncologists.

Sentinel lymph node biopsy in contralateral prophylactic mastectomy: are we overtreating? Experience at a tertiary care hospital.

OBJECTIVE: Use of routine sentinel lymph node biopsy (SLNB) in contralateral prophylactic mastectomy (CPM) is controversial. This retrospective study was undertaken to determine the frequency of SLNB in CPM at a community hospital and its utility as a guide to patient decision making. METHODS: Between 2007 and 2009, 170 patients underwent CPM at a suburban, tertiary care facility. The CPM was either immediate or delayed, or was for ipsilateral recurrent breast cancer. Thirty-seven (21.8%) of 170 patients had SLNB performed with CPM. The mastectomy specimens underwent standard pathologic evaluation by using intraoperative touch preparation cytology and postoperative hematoxylin and eosin staining and immunohistochemistry. RESULTS: No patients who underwent SLNB had positive nodes on touch preparation or final hematoxylin and eosin staining (0/37 [0%]). Fourteen (8.2%) of 37 patients had additional nodes identified in the specimens. These were either axillary tail or intramammary nodes. The median number of SLNs removed was 2 (range, 1-5), none of these were positive. There were 3 incidental cancers diagnosed on final pathology. Two invasive cancers (T1a and grade I) and 1 ductal carcinoma in situ were identified. SLNB was only performed on the patient with DCIS. Neither SLNB nor subsequent axillary lymph node dissection was performed in the invasive cancers. CONCLUSIONS: SLNB was performed in 37 (21.8%) of patients who underwent CPM in a community hospital. Only 3 (1.76%) of 170 patients who underwent CPM had findings on final pathology that would have justified axillary staging. This correlates with other published data regarding SLNB in CPM. Because SLNB is associated with significant morbidity, guidelines for SLNB in prophylactic mastectomy need to be established so to avoid overtreatment.

Optimal use of re-excision in patients diagnosed with early-stage breast cancer by excisional biopsy treated with breast-conserving therapy.

PURPOSE: The goal of the current study is to help refine guidelines for the need for re-excision and the appropriate amount of breast tissue to re-excise in patients with early breast cancer following excisional breast biopsy when treated with breast-conserving therapy (BCT). PATIENTS AND METHODS: The study population consisted of 441 patients derived from a dataset of 607 consecutive cases of stage I and II breast cancer treated with BCT, in which patients underwent primary excisional diagnostic biopsy and subsequent re-excision prior to the initiation of radiation therapy (RT). A single pathologist reviewed all specimens. Re-excision was indicated because tumor was found close to or involving the resection margin. In 333 of the 441 cases, it was possible to measure the extension of carcinoma into the re-excision specimen. Margins were classified as negative (carcinoma>4.2 mm from the margin), near (<4.2 mm from the margin) or positive. Any carcinoma identified near the final margin was quantified by width of invasive carcinoma and number of ductal carcinoma in situ (DCIS) ducts near the margin and subdivided into three distinct groups: least, intermediate, and greatest amount. These factors were then analyzed to determine the likelihood and extent of residual carcinoma in re-excision specimens. Statistical analysis was performed using Systat version 10 (SPSS Inc., Chicago, IL). RESULTS: The quantity of carcinoma near the initial biopsy margin and the invasive carcinoma-to-specimen dimension ratio demonstrated a significant association with increasing amounts of residual carcinoma at re-excision. Combination of these two variables allowed for a statistically significant (P<0.001) calculation of risk index for identifying significant residual invasive carcinoma or DCIS in the adjacent breast parenchyma at re-excision, and yielded stratification into low- (6%), intermediate- (27%), and high-risk (44%) groups. In re-excision specimens, the observed distance of carcinoma extension into adjacent breast tissue was associated with a statistically significant decrease in the ratio of the initial excisional biopsy specimen dimensions and invasive carcinoma dimensions. Combining the initial margin status with the specimen-to-invasive carcinoma maximum dimension ratio yielded an accurate predictor of the maximum distance of tumor extension. CONCLUSIONS: Evaluation of the initial excisional biopsy margin status in correlation with the invasive carcinoma-to-specimen maximum dimension ratio may be helpful for (1) identifying patients who require re-excision prior to RT and (2) predicting the quantity of additional breast tissue to excise to ensure adequate surgical margins with BCT.

Molecular classification system identifies invasive breast carcinoma patients who are most likely and those who are least likely to achieve a complete pathologic response after neoadjuvant chemotherapy.

BACKGROUND: The molecular classification system categorizes invasive breast carcinomas according to their key driving biomarkers. In the current study, the authors evaluated whether response to neoadjuvant chemotherapy was correlated with the molecular classification groups. METHODS: Using immunohistochemistry, the molecular classification group (luminal-A, luminal-B, HER-2-variant, HER-2-classic, and basal phenotype) was retrospectively determined in 68 breast cancer patients who received neoadjuvant treatment. RESULTS: A total of 28 carcinoma patients (41.2%) achieved a compete pathologic response (CPR), including 2 of 15 patients classified as having luminal-A (13.3%), 4 of 16 patients classified as having luminal-B (25.0%), 10 of 12 patients classified as having HER-2-classic (83.3%), none of the 4 patients classified as having HER-2-variant, and 12 of 21 patients classified as having basal phenotype (57.1%) neoplasms. The CPR rate among patients with the HER-2-classic and basal neoplasms was 67% (22 of 33 neoplasms), compared with 17.1% (6 of 35 neoplasms) in the non-HER-2-classic/basal combined group (P < .001). Eleven carcinomas were initially diagnosed as invasive lobular carcinomas (pleomorphic and classic), 4 of which were luminal-A, 4 of which were luminal-B, 2 of which were HER-2-classic, and 1 of which was basal. On review, only 3 of these 11 cases remained classified as classic lobular carcinoma, all of which were classified as luminal-A, and none of these patients achieved a CPR. Four of the other 8 patients achieved a CPR. CONCLUSIONS: The molecular classification system is useful for identifying carcinoma patients who are most likely and those who are least likely to achieve a CPR. In the current study, all the morphologically classic lobular carcinomas were classified as luminal-A neoplasms, which may explain the low rate of CPR reported.