Society of Surgical Oncology Breast Disease Site Working Group Statement on Contralateral Mastectomy: Indications, Outcomes, and Risks.

Rates of contralateral mastectomy (CM) among patients with unilateral breast cancer have been increasing in the United States. In this Society of Surgical Oncology position statement, we review the literature addressing the indications, risks, and benefits of CM since the society's 2017 statement. We held a virtual meeting to outline key topics and then conducted a literature search using PubMed to identify relevant articles. We reviewed the articles and made recommendations based on group consensus. Patients consider CM for many reasons, including concerns regarding the risk of contralateral breast cancer (CBC), desire for improved cosmesis and symmetry, and preferences to avoid ongoing screening, whereas surgeons primarily consider CBC risk when making a recommendation for CM. For patients with a high risk of CBC, CM reduces the risk of new breast cancer, however it is not known to convey an overall survival benefit. Studies evaluating patient satisfaction with CM and reconstruction have yielded mixed results. Imaging with mammography within 12 months before CM is recommended, but routine preoperative breast magnetic resonance imaging is not; there is also no evidence to support routine postmastectomy imaging surveillance. Because the likelihood of identifying an occult malignancy during CM is low, routine sentinel lymph node surgery is not recommended. Data on the rates of postoperative complications are conflicting, and such complications may not be directly related to CM. Adjuvant therapy delays due to complications have not been reported. Surgeons can reduce CM rates by encouraging shared decision making and informed discussions incorporating patient preferences.

Clinical efficacy of PARP inhibitors in breast cancer.

BRCA1 and BRCA2 are key tumor suppressor genes that are essential for the homologous recombination DNA repair pathway. Loss of function mutations in these genes result in hereditary breast and ovarian cancer syndromes, which comprise approximately 5% of cases. BRCA1/2 mutations are associated with younger age of diagnosis and increased risk of recurrences. The concept of synthetic lethality led to the development of PARP inhibitors which cause cell cytotoxicity via the inhibition of PARP1, a key DNA repair protein, in cells with germline BRCA1/2 mutations. Although still poorly understood, the most well-acknowledged proposed mechanisms of action of PARP1 inhibition include the inhibition of single strand break repair, PARP trapping, and the upregulation of non-homologous end joining. Olaparib and talazoparib are PARP inhibitors that have been approved for the management of HER2-negative breast cancer in patients with germline BRCA1/2 mutations. This review article highlights the clinical efficacy of PARP inhibitors in patients with HER2-negative breast cancer in early and advanced settings.

Uveitis, a rare but important complication of adjuvant zoledronic acid for early-stage breast cancer.

Bisphosphonates such as zoledronic acid are an important part of adjuvant therapy to reduce the risk of recurrence in early-stage breast cancer. Uveitis remains one of the lesser-known side effects of zoledronic acid; prompt recognition is essential to ensure patients receive appropriate and timely care to help prevent permanent vision loss. We report a case of anterior uveitis in a postmenopausal woman who presented with visual symptoms after receiving the first dose of zoledronic acid. This case report serves to educate and increase awareness of the risk of uveitis in patients who are given zoledronic acid. This is the first and only reported case of zoledronic acid when used in the adjuvant setting for the treatment of breast cancer.

Patterns of postmastectomy radiation therapy in clinically node-positive breast cancerpatients with pathologically negative lymph nodes after neoadjuvant chemotherapy.

BACKGROUND: To analyze postmastectomy radiation therapy (PMRT) utilization and its association with overall survival (OS) in patients presenting with node-positive breast cancer who are pathologically node-negative (ypN0) after neoadjuvant chemotherapy (NAC). METHODS: Using the National Cancer Data Base (NCDB), we identified patients diagnosed between 2004 and 2013 with clinical T1-4 node-positive nonmetastatic breast cancer who received NAC and underwent mastectomy with pathologically negative lymph node sampling. Multivariable regression models identified factors associated with PMRT use. The Cox proportional hazards model was used to evaluate predictors of mortality. RESULTS: The study included 8766 clinically node-positive patients who met the study criteria. PMRT was delivered to 61.5% of patients. Overall PMRT utilization rate increased over the study period from 54.4% in 2004 to 65.2% in 2011. Predictors of PMRT use included larger tumor size, increasing clinical N stage, higher grade disease, receipt of hormone therapy, and a greater number of lymph nodes examined. The unadjusted 5-year OS was 84.1% in the PMRT group and 83.8% in the non-PMRT group (p = NS). PMRT was not significantly associated with survival on multivariable analysis (hazard ratio [HR] 0.87; 95% confidence interval [CI] 0.73-1.03). DISCUSSION: The delivery of PMRT has increased over time in women presenting with clinically node-positive breast cancer who convert to ypN0 after NAC. While we identified multiple independent socioeconomic and clinical predictors of both PMRT utilization and survival, PMRT itself was not significantly associated with survival.

Incidence of clinical lymphedema in breast cancer patients treated with adjuvant proton-based radiotherapy.

Background: The purpose of this study was to evaluate the incidence of clinical lymphedema following adjuvant proton-based radiotherapy (RT) in breast cancer (BC) patients. Materials and methods: We performed a retrospective review of our institutional database to identify BC patients treated with adjuvant proton-based RT. Patients receiving re-irradiation for a BC recurrence or those with a history of ipsilateral chest wall radiation were excluded. Clinical lymphedema was determined by documentation in the chart at baseline and during follow-up. Results: We identified 28 patients treated with adjuvant proton-based RT who met the study criteria. Median age at diagnosis was 45 (range, 24-75). Eleven patients (39%) underwent mastectomy, and fourteen (50%) underwent axillary lymph node dissection (ALND). Median number of LNs removed was 6 (range, 1-28). Nineteen patients (68%) received neoadjuvant chemotherapy. Median whole breast/chest wall dose delivered was 50 Gy (range, 44-54.0 Gy). Target volumes included the axillary and supraclavicular lymph nodes in all patients and internal mammary lymph nodes in 27 (96%) patients. Mean dose to the axilla was 49.7 Gy, and mean dose to 95% of the axillary volume (D95) was 46.3 Gy (94% of prescription dose). Mean dose to supraclavicular (SCV) volume was 47.7 Gy, and D95 was 44.1 Gy (91% of prescription dose). Grade 3 dermatitis occurred in 14% of patients. Five patients (18%) had clinical lymphedema, 4 from the ALND subset (n = 14). Conclusions: The incidence of clinical lymphedema after proton-based RT is comparable to rates reported with photon-based RT with comprehensive nodal coverage.

Patterns of post-mastectomy radiation therapy in clinically node positive breast cancer patients with pathologically negative lymph nodes after neoadjuvant chemotherapy.

BACKGROUND: To analyze postmastectomy radiation therapy (PMRT) utilization and its association with overall survival (OS) in patients presenting with node positive breast cancer who are pathologically node negative (ypN0) after neoadjuvant chemotherapy (NAC). MATERIALS AND METHODS: Using the National Cancer Data Base (NCDB), we identified patients diagnosed between 2004 and 2013 with clinical T1-4 node-positive non-metastatic breast cancer who received NAC and underwent mastectomy with pathologically negative lymph node sampling. Multivariable regression models identified factors associated with PMRT use. The Cox proportional hazards model was used to evaluate predictors of mortality. RESULTS: The study included 8,766 clinically node-positive patients who met the study criteria. PMRT was delivered to 61.5% of patients. Overall PMRT utilization rate increased over the study period from 54.4% in 2004 to 65.2% in 2011. Predictors of PMRT use included larger tumor size, increasing clinical N stage, higher grade disease, receipt of hormone therapy, and greater number of lymph nodes examined. Unadjusted 5-year OS was 84.1% in the PMRT group and 83.8% in the non-PMRT group (p=NS). PMRT was not significantly associated with survival on multivariable analysis (hazard ratio [HR] 0.87; 95% confidence interval [CI] 0.73-1.03). CONCLUSION: The delivery of PMRT has increased over time in women presenting with clinically node positive breast cancer who convert to ypN0 after NAC. While we identified multiple independent socioeconomic and clinical predictors of both PMRT utilization and survival, PMRT itself was not significantly associated with survival.

Breast cancer risk factor associations differ for pure versus invasive carcinoma with an in situ component in case-control and case-case analyses.

PURPOSE: Invasive ductal carcinoma (IDC) is diagnosed with or without a ductal carcinoma in situ (DCIS) component. Previous analyses have found significant differences in tumor characteristics between pure IDC lacking DCIS and mixed IDC with DCIS. We will test our hypothesis that pure IDC represents a form of breast cancer with etiology and risk factors distinct from mixed IDC/DCIS. METHODS: We compared reproductive risk factors for breast cancer risk, as well as family and smoking history between 831 women with mixed IDC/DCIS (n = 650) or pure IDC (n = 181), and 1,620 controls, in the context of the Women's Circle of Health Study (WCHS), a case-control study of breast cancer in African-American and European-American women. Data on reproductive and lifestyle factors were collected during interviews, and tumor characteristics were abstracted from pathology reports. Case-control and case-case analyses were conducted using unconditional logistic regression. RESULTS: Most risk factors were similarly associated with pure IDC and mixed IDC/DCIS. However, among postmenopausal women, risk of pure IDC was lower in women with body mass index (BMI) 25 to <30 [odds ratio (OR) 0.66; 95 % confidence interval (CI) 0.35-1.23] and BMI ≥ 30 (OR 0.33; 95 % CI 0.18-0.67) compared to women with BMI < 25, with no associations with mixed IDC/DCIS. In case-case analyses, women who breastfed up to 12 months (OR 0.55; 95 % CI 0.32-0.94) or longer (OR 0.47; 95 % CI 0.26-0.87) showed decreased odds of pure IDC than mixed IDC/DCIS compared to those who did not breastfeed. CONCLUSIONS: Associations with some breast cancer risk factors differed between mixed IDC/DCIS and pure IDC, potentially suggesting differential developmental pathways. These findings, if confirmed in a larger study, will provide a better understanding of the developmental patterns of breast cancer and the influence of modifiable risk factors, which in turn could lead to better preventive measures for pure IDC, which have worse disease prognosis compared to mixed IDC/DCIS.

Impact of American College of Surgeons Oncology Group Z11 on surgical training at an academic cancer center.

BACKGROUND: The application of the American College of Surgeons Oncology Group Z0011 trial (Z11) has resulted in fewer completion axillary lymph node dissections (ALNDs) for select patients. We hypothesize that the application of Z11 may result in fewer ALND cases for surgeons in training. METHODS: In the setting of an academic cancer center incorporating Z11 into routine practice, we compared the total number of ALND performed in a pre-Z11 period (January 2007-April 2011, 52 mo) and post-Z11 period (April 2011-February 2014, 34 mo). We also identified the number of patients in the post-Z11 era in whom ALND was omitted as a result of Z11. Clinical and pathologic characteristics among these groups were analyzed. RESULTS: A total of 279 and 191 ALNDs were performed in the pre-Z11 and post-Z11 groups, respectively. Variables were similar among these groups with respect to demographics, tumor characteristics, and surgeries performed. There was no difference in the monthly rates of ALND between groups-5.37 cases/mo (pre-Z11) and 5.62 cases/mo (post-Z11), P = 0.52. We identified a total of 53 patients for whom ALND was omitted due to Z11 application in the post-Z11 period, representing a potential 21.7% decrease (53/191 + 53) in the number of ALNDs in this period. CONCLUSIONS: Although the application of Z11 could potentially impact surgical training with a 21.7% decrease in ALND cases (53/191 + 53), the surgical case volume at an academic cancer center absorbs this decrease and maintains consistent levels of training for ALND.

The use of modified four-dimensional computed tomography in patients with primary hyperparathyroidism: an argument for the abandonment of routine sestamibi single-positron emission computed tomography (SPECT).

BACKGROUND: Four-dimensional computed tomography (4D CT) has emerged as an extremely sensitive preoperative imaging modality for primary hyperparathyroidism compared with the historical use of sestamibi and ultrasound (US). Specialized volume rendering and technical modifications further enhance this technique for operative guidance while reducing radiation exposure. METHODS: Patients undergoing parathyroidectomy for primary hyperparathyroidism from December 2010 to September 2013, carried out by two surgeons at a tertiary cancer center, were evaluated. Comparison was made between the three imaging modalities (4D CT, sestamibi, and US) for preoperative localization rate and accuracy. Biochemical parameters and radiation exposure were also analyzed. RESULTS: A total of 202 patients were identified from the database and 200 patients were included in the analysis. All patients underwent 4D CT (100 %), 185 sestamibi (92.5 %) and 186 US (93 %). In patients with single-gland disease (n = 153), 4D CT, sestamibi, and US were positive in 96 %, 65.4 % and 57.7 % of patients, respectively and, when positive, were accurately localized in 97.2 %, 93.4 % and 96.3 % of patients, respectively. In patients with multigland disease (MGD) [n = 47], 4D CT, sestamibi, and US predicted MGD in 32 %, 0 %, and 13.6 % of patients, respectively. With our technique modification, radiation exposure from 4D CT approached that of sestamibi. CONCLUSIONS: Low-dose, modified 4D CT with volume rendering when compared with sestamibi has a statistically significant higher positivity rate, improved accuracy rate, provides excellent images, superior surgical planning, and has a comparable radiation exposure risk profile. Consideration should be made for the abandonment of routine sestamibi single-positron emission computed tomography (SPECT), with 4D CT as the preoperative imaging modality of choice.

Breast Cancer Risk Reduction, Version 2.2015.

Breast cancer is the most frequently diagnosed malignancy in women in the United States and is second only to lung cancer as a cause of cancer death. To assist women who are at increased risk of developing breast cancer and their physicians in the application of individualized strategies to reduce breast cancer risk, NCCN has developed these guidelines for breast cancer risk reduction.

Long-Term Clinical and Cosmetic Outcomes of Once-Daily Accelerated Partial Breast Irradiation in Early Breast Cancer.

Purpose: Accelerated partial breast irradiation (APBI) is one of the standard treatment options in early-stage node negative breast cancer in selected patients. However, the optimal dose fractionation schedule still represents a challenge. We present the 12-year follow up results of clinical and cosmetic outcomes of once daily APBI with external beam radiation therapy which provides an APBI radiation dose equivalent to the whole breast radiation with a boost. Methods and Materials: From July 2008 to August 2010, we enrolled 34 patients with T1, T2 (< 3cm) N0 to receive once daily APBI with three dimensional conformal radiation therapy (3D-CRT) to a total dose of 49.95 Gy over 15 single daily fractions over 3 weeks at 3.33 Gy per fraction. Ipsilateral breast tumor recurrence (IBTR), acute toxicity, late toxicity and cosmesis was analyzed. The median follow-up for all patients is 144 months (12 years). Results: The median age of the patients was 61 years (range 46-83). Nine patients had ductal carcinoma in situ (DCIS) and 25 patients had invasive cancer. The median size of the tumor with DCIS pathology was 0.5 cm, while median size of the tumor with invasive cancer pathology was 1.0 cm. All of the patients had negative margins and negative nodes. Two IBTR was observed (5.8%). One patient had DCIS at recurrence and other had invasive recurrence. Two patients died due to non-cancer cause. The 12-year actuarial ipsilateral breast recurrence free survival was 93.5% and the 12-year actuarial overall survival was 93.2%. Late Grade 2 toxicity was observed in 6 patients and late grade 3 toxicity was seen in 1 patient. 91% of the patients had excellent to good cosmesis. Conclusions: This novel APBI dosing schema is based on an equivalent dose compared to whole breast radiation plus a tumor bed boost. This once daily APBI scheme is well-tolerated and demonstrates good to excellent cosmetic outcome and low rates of late complications on long term follow-up.

ESR1 and p53 interactome alteration defines mechanisms of tamoxifen response in luminal breast cancer.

The canonical mechanism behind tamoxifen's therapeutic effect on estrogen receptor α/ESR1+ breast cancers is inhibition of ESR1-dependent estrogen signaling. Although ESR1+ tumors expressing wild-type p53 were reported to be more responsive to tamoxifen (Tam) therapy, p53 has not been factored into choice of this therapy and the mechanism underlying the role of p53 in Tam response remains unclear. In a window-of-opportunity trial on patients with newly diagnosed stage I-III ESR1+/HER2/wild-type p53 breast cancer who were randomized to arms with or without Tam prior to surgery, we reveal that the ESR1-p53 interaction in tumors was inhibited by Tam. This resulted in functional reactivation of p53 leading to transcriptional reprogramming that favors tumor-suppressive signaling, as well as downregulation of oncogenic pathways. These findings illustrating the convergence of ESR1 and p53 signaling during Tam therapy enrich mechanistic understanding of the impact of p53 on the response to Tam therapy.

Time-trends in survival in young women with breast cancer in a SEER population-based study.

Mortality improvements in young women with breast cancer (BC) may be attributable to treatment advances; screening likely plays a less significant role as mammography is not recommended <40. We examined time-trends in outcome in a cohort of young women. Our goal was to determine the contributions of treatment and screening to mortality improvements and evaluate whether differential outcomes by ER status exist. Using SEER, patients (73,447) were divided into three categories by diagnosis year (1990-1994, 1995-1999, 2000-2004) and also categorized as <40 or 40-50 years. Multivariate analysis was done to investigate the association of survival with time period for both age groups by ER status. Hazard ratios (HR) for mortality in women 40-50 with ER positive BC declined over time. With 1990-1994 as referent, the HR in 1995-1999 was 0.77 (0.69-0.86) and 0.65 (0.59-0.71) in 2000-2004 (p < 0.001). Women <40 with ER positive BC also had improvements over time. In ER negative patients, the degree of improvements over time was less than that seen in ER positive women. We report a survival disparity over time in young women by ER status. Patients with ER negative disease have not had the degree of improvements over time as seen in ER positive disease. Therefore, mortality improvements in young women with ER positive BC may be attributed to treatment advances with endocrine agents.

Early Toxicity and Patient-Reported Cosmetic Outcomes in Patients Treated With Adjuvant Proton-Based Radiotherapy After Breast-Conserving Surgery.

INTRODUCTION: To evaluate the dosimetric data, early toxicity, and patient-reported cosmetic outcomes in breast cancer patients treated with adjuvant proton-based radiotherapy (RT) after breast-conserving surgery. MATERIALS AND METHODS: We performed a retrospective review of our institutional database to identify breast cancer patients treated with breast-conserving surgery followed by proton-based RT from 2015 to 2020. Patient-reported cosmetic outcomes were graded as excellent, good, fair, or poor. Early toxicity outcomes were graded by the treating physician during treatment. Dose-volume histograms were reviewed to obtain dosimetry data. RESULTS: We identified 21 patients treated with adjuvant proton-based RT. Median whole breast dose delivered was 46.8 Gy (range, 40.0-50.4 Gy). Target volumes included the regional lymph nodes in 17 patients (81%). Seventeen patients (81%) received a lumpectomy boost. The median planning target volume V95 was 94% (range, 77%-100%), V100 71% (range, 60%-97%), V110 2% (range 0%-18%), and median max point dose was 115% (range, 105%-120%). The median ipsilateral breast V105 was 367.3 cc (range, 0-1172 cc) and V110 was 24.1 cc (range, 0-321.3 cc). Grade 2 and 3 dermatitis occurred in 62% and 14% of patients, respectively. Grade 2 and 3 pain was reported by 33% and 10% of patients, respectively. Median follow-up at the time of cosmetic evaluation was 27 months (range, 5-42 months). Four patients (21%) reported fair cosmetic outcome and 15 patients (79%) reported good or excellent cosmetic outcome. No poor cosmesis was reported. CONCLUSION: Adjuvant proton-based radiotherapy after breast-conserving surgery is well tolerated with acceptable rates of acute toxicities and a high rate of good-to-excellent patient-reported cosmetic outcomes.

The Use of Intraoperative Ultrasound During Breast Conserving Surgery.

OBJECTIVES: The purpose of this study is to evaluate the utilization of intraoperative ultrasound (IOUS) for tumor localization in breast-conserving surgery and to examine its impact on margin positivity and re-excision rates. Additionally, the study seeks to identify factors contributing to surgeon utilization of IOUS. METHODS: A retrospective chart review was conducted of patients with preoperative diagnosis of breast cancer undergoing breast-conserving surgery by breast surgeons at multiple centers within a single healthcare system. Characteristics such as lesion size, palpability, histology, receptor status, and use of neoadjuvant chemotherapy were recorded. Re-excision rates were determined based on localization technique and surgeons' status of breast ultrasound certification. RESULTS: A total of 671 cases were performed, with 322 meeting study inclusion. 57 cases utilized IOUS, 250 utilized preoperative wire-guided localization (WGL), 10 used both methods and 5 cases used neither method. There was no significant difference in re-excision rates between IOUS and WGL or among the four surgeons. Ultrasound-certified surgeons were more likely to utilize IOUS, and re-excision rates trended higher for WGL, which may be clinically significant. CONCLUSION: Increasing familiarity with and utilization of IOUS during breast-conserving surgery may be clinically advantageous over traditional localization techniques. Ultrasound certification may lead to increased use of IOUS among surgeons.

Diagnosis, Management, and Surveillance for Patients With PALB2, CHEK2, and ATM Gene Mutations.

BACKGROUND: This study aims to capture clinical and surgical practice patterns of patients with deleterious mutations in partner and localizer of BRCA2 (PALB2), checkpoint kinase 2 (CHEK2) and ataxia telangiesctasia mutated (ATM) genes. MATERIALS AND METHODS: This study is a retrospective chart review of patients with PALB2, CHEK2 or ATM mutations. Patient demographics, testing indications, management decisions, and surveillance strategies were recorded. RESULTS: Sixty-two patients were found to have deleterious mutations: 14 (23%) with a PALB2 mutation, 30 (48%) with a CHEK2 mutation, and 18 (29%) patients with an ATM mutation. Thirty-one (50%) patients have a history of breast cancer. Twenty-three patients were diagnosed and treated prior to genetic testing while 8 patients learned of their mutation status and breast cancer diagnosis simultaneously. Of these 8 patients, 4 sought treatment at our institution, 3 underwent bilateral mastectomy, and 1 patient opted for lumpectomy and surveillance. Thirty-one patients had no history of breast cancer. After genetic diagnosis, 3 of the 9 patients who continued clinical follow-up proceeded with bilateral prophylactic mastectomy within 2 years. Clinical surveillance continued for 23 months on average. CONCLUSION: Most patients who learned of their genetic and breast cancer diagnoses simultaneously underwent bilateral mastectomy, whereas only a third of patients without cancer opted for bilateral prophylactic mastectomy.

Reconstructive complications and early toxicity in breast cancer patients treated with proton-based postmastectomy radiation therapy.

Background: Postmastectomy radiation therapy (PMRT) decreases the risk of locoregional recurrence and increases overall survival rates in patients with high-risk node positive breast cancer. While the number of breast cancer patients treated with proton-based PMRT has increased in recent years, there is limited data on the use of proton therapy in the postmastectomy with reconstruction setting. In this study, we compared acute toxicities and reconstructive complications in patients treated with proton-based and photon-based PMRT. Methods: A retrospective review of our institutional database was performed to identify breast cancer patients treated with mastectomy with implant or autologous reconstruction followed by PMRT from 2015 to 2020. Baseline clinical, disease, and treatment related factors were compared between the photon-based and proton-based PMRT groups. Early toxicity outcomes and reconstructive complications following PMRT were graded by the treating physician. Results: A total of 11 patients treated with proton-based PMRT and 26 patients treated with photon-based PMRT were included with a median follow-up of 7.4 months (range, 0.7-33 months). Six patients (55%) in the proton group had a history of breast cancer (3 ipsilateral and 3 contralateral) and received previous RT 38 months ago (median, range 7-85). There was no significant difference in mean PMRT (p = 0.064) and boost dose (p = 0.608) between the two groups. Grade 2 skin toxicity was the most common acute toxicity in both groups (55% and 73% in the proton and photon group, respectively) (p = 0.077). Three patients (27%) in the proton group developed grade 3 skin toxicity. No Grade 4 acute toxicity was reported in either group. Reconstructive complications occurred in 4 patients (36%) in the proton group and 8 patients (31%) in photon group (p = 0.946). Conclusions: Acute skin toxicity remains the most frequent adverse event in both proton- and photon-based PMRT. In our study, reconstructive complications were not significantly higher in patients treated with proton- versus photon-based PMRT. Longer follow-up is warranted to assess late toxicities.

Toxicities and Locoregional Control After External Beam Chest Wall and/or Regional Lymph Node Re-irradiation for Recurrent Breast Cancer.

BACKGROUND/AIM: To evaluate toxicities and clinical outcomes in breast cancer (BC) patients who underwent external beam chest wall (CW) and/or regional lymph node (LN) re-irradiation (re-RT) for locoregional recurrence (LRR). PATIENTS AND METHODS: We performed a retrospective review of our institutional database to identify BC patients diagnosed with an isolated ipsilateral CW or nodal recurrence after prior whole breast/CW irradiation. RESULTS: Fifteen patients met the study criteria. Median time between completion of RT courses was 68.3 months (range=7.8-245.4 months). Median CW re-RT dose was 45 Gy (range=42.3-50.4 Gy). The majority of patients (80%) received proton beam re-RT. Grade 2-3 dermatitis occurred in 87% patients. Grade 2-3 pain was reported by 33% of patients. At a median follow-up of 14 months (range=1.0-90.5 months), the rate of isolated LRR was 13%. CONCLUSION: Re-RT of the CW and/or regional LNs is feasible with acceptable rates of toxicity and low rates of isolated LRR.

Does the Use of BioZorb® Result in Smaller Breast Seroma Volume?

AIM: To evaluate the impact of BioZorb®, a 3D-bioabsorbable marker, on the tumor-bed boost volume and dosimetric parameters in adaptive boost planning for breast cancer. PATIENTS AND METHODS: Records were reviewed for 51 breast-cancer patients who underwent breast-conserving surgery and adjuvant whole-breast irradiation between January 2017 and October 2018. Changes in lumpectomy boost volume (LBV), doses to organs at risk, toxicity and cosmesis were compared between patients with and without BioZorb® Chi-square test and paired and independent t-tests were used for comparisons of variables. RESULTS: Median follow-up was 35.5 months. Mean LBV on initial CT (LBV1; 32.2 vs. 33.8 cc, p=0.74) and on boost computed tomography (CT) (LBV2; 25.3 vs. 24.8 cc, p=0.87) were similar with and without BioZorb® The mean decrease from LBV1 to LBV2 was 9.0 cc and 6.8 cc with and without BioZorb®, respectively (p=0.42). LBV1 was significantly positively correlated with a 20% reduction in LBV (p=0.02). Mean heart and lung doses on adaptive boost planning CT were slightly lower compared to initial planning CT in both groups. Acute breast pain was reported in 18/51 patients, 9 of whom had BioZorb® (p=0.24). Grade-2 pain was reported in 5/51 patients, 3 of whom had BioZorb® (p=0.11). Excellent or good cosmesis was reported in 36/41 patients. Fair cosmesis was reported in 5/41 patients, of whom 2 had BioZorb® (p=0.64). CONCLUSION: BioZorb® placement does not impact the tumor-bed boost volume nor the variation of seroma volume within the period of treatment. More data and longer follow-up are needed to identify a measurable clinical impact of BioZorb® placement.

Risk Factors for the Development of Clinical and Subclinical Lymphedema Detected by Bioimpedance Spectroscopy.

BACKGROUND: Breast cancer-related lymphedema can significantly compromise quality of life. Bioimpedance spectroscopy (BIS) measures extracellular fluid in lymphedema. The purpose of this study was to determine the incidence of BIS-detected lymphedema using the L-Dex and identify risk factors associated with a positive score. MATERIALS AND METHODS: We performed a retrospective review of our institutional database to identify patients who underwent L-Dex U400 measurements. Patients with a score of > 10 L-Dex units or with an increase of > 10 units from baseline had a positive score. Clinical lymphedema was determined by documentation in the chart at the time of positive measurement. Otherwise, patients were considered to have subclinical lymphedema. RESULTS: Fifty-three patients met study criteria. Thirty patients (56.6%) underwent mastectomy, 22 (41.5%) axillary lymph node dissection (ALND), and 33 (62.3%) received radiation (RT). Twelve patients (22.6%) had a positive score. There were no differences in age, race, laterality, breast surgery, T stage, N stage, chemotherapy, or RT fields (none, breast only, breast with LNs) in patients with a positive score. ALND was more common (66.7% vs. 34.2%, P= .04). BMI > 30 approached significance (58.3% vs. 29.3%, P= .06). Seven patients had subclinical lymphedema. No differences were identified comparing patients with subclinical lymphedema to those with negative scores. All 5 patients with clinical lymphedema underwent ALND and received nodal RT. CONCLUSION: The combination of ALND and regional nodal RT is strongly associated with development of clinical lymphedema. It is difficult to identify patients at risk for subclinical BIS-detected lymphedema.