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BACKGROUND: HER2-positive breast cancers, which accounts for 20% of breast cancers, is associated with aggressive clinical behavior and inferior survival. The approval of HER2 targeted therapy has changed the landscape of this disease and has reduced disease recurrence by 50% and has improved survival by 33%. (1) However, cardiotoxicity is a well-recognized adverse event associated with HER2-targeted therapies. Adjuvant trastuzumab emtansine (TDM1) is the current standard of care for patients with residual breast cancer after neoadjuvant HER2-targeted therapy. TDM1 is associated with a risk of cardiotoxicity defined as a decline in left ventricular ejection fraction (LVEF). In a pooled analysis of data from seven metastatic breast cancer trials with TDM1, the incidence of cardiac events such as congestive heart failure (CHF), cardiac ischemia, cardiac arrhythmia or grade 1/2 LVEF drop was 3.37%. Adjuvant breast radiation (RT) is routinely offered for patients at high risk for recurrence. Breast RT is also associated with long-term increased risk of cardiac disease more than 10 years after RT. The HERA trial which studied use of adjuvant trastuzumab showed that rates of cardiotoxicity were higher in patients receiving concurrent RT with trastuzumab (left sided > right sided breast cancer) compared to those who did not receive adjuvant RT, although not statistically significant. In the multivariate analysis, no treatment or baseline cardiovascular risk factors were strongly correlated with LVEF, but radiation therapy showed a borderline correlation (adjusted HR, 1.258; 95% CI, 1.00-1.58; P = .049). The risk of cardiotoxicity with concurrent TDM1 and RT has not been well studied. With increasing use of TDM1 in the adjuvant setting, it is important to understand the cardiotoxic effects of combination therapy in early-stage breast cancer. METHODS: We undertook a review of our clinical database to identify patients who received adjuvant TDM1 with concurrent RT for Stage I-III breast cancer from 1/2020 to 01/2022. Clinical parameters including age, date of diagnosis, history of cardiac disorders, echocardiogram findings, radiation dose, final pathologic stage and molecular subtypes of cancer were extracted. All patients had ejection fraction to monitor cardiac fraction. Global longitudinal strain (GLS), which is a more sensitive and reproducible indicator of cardiac dysfunction than LVEF, was also collected, if available. RESULTS: Of 32 patients identified in our retrospective analysis, two patients (6%) developed a drop in ejection fraction post radiation. Median age of patients was 57y. Majority of the patients were Caucasian (44%) followed by Hispanic (28%). 19 (60%) patients had right sided breast cancers and 13(40%) patients had left sided cancers. The mean pre-radiation ejection fraction was 60% and post radiation was 61%. Using paired t-testing, there was no statically significant difference in ejection fraction after radiation (p=0.343). Comparative GLS measurements were available for 16 patients and there was no statical difference with concurrent radiation (p=0.18). All patients tolerated radiation with mostly grade 2 skin dermatitis except four patients who had grade 3 skin dermatitis. One patient had to discontinue radiation early given grade 3 skin dermatitis. CONCLUSION: This institutional review of 32 patients suggests that adjuvant TDM1 with concurrent RT did not result in a significant change in ejection fraction or GLS. Most patients tolerated radiation without significant skin toxicities. One of the limitations of the study is the small sample size. A larger study should look at more broader conclusions; however this data has strong clinical implications. Cardiac Parameters pre and post RT Citation Format: Faheem Farooq, Dillon Cason, Nisha Ohri, Shicha Kumar, Allison Grann, Anna Litvak, Shridar Ganesan, Bruce G. Haffty, Deborah Toppmeyer, Coral Omene, Mridula A. George. Evaluating the risk of cardiotoxicity associated with concurrent trastuzumab emtansine (TDM1) and radiation therapy in patients with early-stage HER2 positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-07-08.

Stereotactic radiosurgery (SRS) is a treatment option in the initial management of patients with brain metastases. While its efficacy has been demonstrated in several prior studies, treatment-related complications, particularly symptomatic radiation necrosis (RN), remains as an obstacle for wider implementation of this treatment modality. We thus examined risk factors associated with the development of symptomatic RN in patients treated with SRS for brain metastases.We performed a retrospective review of our institutional database to identify patients with brain metastases treated with SRS. Diagnosis of symptomatic RN was determined by appearance on serial MRIs, MR spectroscopy, requirement of therapy, and the development of new neurological complaints without evidence of disease progression.We identified 323 brain metastases treated with SRS in 170 patients from 2009 to 2018. Thirteen patients (4%) experienced symptomatic RN after treatment of 23 (7%) lesions. After SRS, the median time to symptomatic RN was 8.3 months. Patients with symptomatic RN had a larger mean target volume (p0.0001), and thus larger V100% (p0.0001), V50% (p0.0001), V12Gy (p0.0001), and V10Gy (p=0.0002), compared to the rest of the cohort. Single-fraction treatment (p=0.0025) and diabetes (p=0.019) were also significantly associated with symptomatic RN.SRS is an effective treatment option for patients with brain metastases; however, a subset of patients may develop symptomatic RN. We found that patients with larger tumor size, larger plan V100%, V50%, V12Gy, or V10Gy, who received single-fraction SRS, or who had diabetes were all at higher risk of symptomatic RN.

Adjuvant therapy has become a crucial part in reducing risk of recurrence after surgical intervention. Bisphosphonates such as zoledronic acid have been used as part of adjuvant therapy. Among its many side-effects, zoledronic acid also carries a risk of uveitis. Uveitis remains one of many lesser-known side-effects; 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 post-menopausal 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.

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.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.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.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.

Whole breast radiation therapy (RT) has become standard of care in early stage breast cancer treatment following lumpectomy. Predictors of RT completion have been sparsely studied, with no previous nationwide examination of the impact of fractionation regimen on completion rate.The National Cancer Database identified patients with early stage breast cancer having undergone lumpectomy and RT from 2004 through 2015. Fraction size of 1.8-2.0 Gray (Gy) was defined as standard fractionation (SFRT); 2.66-2.70 Gy/fraction as hypofractionation (HFRT). RT completion was defined as receipt of at least 46 Gy for SFRT and 40 Gy for HFRT. A multivariable logistic regression model characterized RT completion predictors.A total of 100,734 patients were identified where fraction size could be reliably characterized as above; more than 87% completed RT. Of these, 66.8% received SFRT, yet HFRT use significantly increased over time (5.2% increase/year; P .0001). RT completion rates were significantly greater following HFRT (99.3%) versus SFRT (79.7%); patients receiving SFRT had higher odds of not completing RT (odds ratio, 41.5; 95% confidence interval, 36.6-47.1; P .0001). Multivariable analysis revealed that African-American and Caucasian patients treated with SFRT versus HFRT had 22 and 43 times the odds of not completing RT, respectively (P .0001).SFRT remained the majority of RT fractionation in the studied time period, although HFRT use has increased over time. Patients residing10 miles from a treatment facility or of African-American race had lower odds of completing RT, as were patients treated with SFRT versus HFRT. These findings suggest compliance advantages of HFRT for patients with early stage breast cancer having undergone lumpectomy.

Uveal melanoma (UM), the most frequently occurring non-cutaneous melanoma and most common primary intraocular malignancy in adults, arises from the melanocytes of the choroid in approximately 95% of cases. Prompt diagnosis and treatment is vital as primary tumor size is one of the key factors associated with survival. Despite recent advances in management, more than half of the patients develop metastatic disease which portends poor survival. Currently, treatment options for UM include local resection, enucleation, plaque brachytherapy, and/or particle beam radiotherapy (RT). Enucleation was initially the standard of care in the management of UM, but a shift towards eye-preserving therapeutic choices such as RT and local resection has been noted in recent decades. Plaque brachytherapy, a form of localized RT, is the most popular option and is now the preferred treatment modality for a majority of UM cases. In this review we discuss the etiopathogenesis, clinical presentation and diagnosis of UM and place a special emphasis on its therapeutic options. Furthermore, we review the current literature on UM management and propose a functional treatment algorithm for non-metastatic disease.

Purpose Approximately 10% of patients who received brain stereotactic radiosurgery (SRS) develop symptomatic radiation necrosis (RN). We sought to determine the effectiveness of treatment options for symptomatic RN, based on patient-reported outcomes. Materials and methods We conducted a retrospective review of 217 patients with 414 brain metastases treated with SRS from 2009 to 2018 at our institution. Symptomatic RN was determined by appearance on serial magnetic resonance images (MRIs), MR spectroscopy, requirement of therapy, and development of new neurological complaints without evidence of disease progression. Therapeutic interventions for symptomatic RN included corticosteroids, bevacizumab and/or surgical resection. Patient-reported therapeutic outcomes were graded as complete response (CR), partial response (PR), and no response. Results Twenty-six patients experienced symptomatic RN after treatment of 50 separate lesions. The mean prescription dose was 22 Gy (range, 15 to 30 Gy) in 1 to 5 fractions (median, 1 fraction). Of the 12 patients managed with corticosteroids, 6 patients (50%) reported CR and 4 patients (33%) PR. Of the 6 patients managed with bevacizumab, 3 patients (50%) reported CR and 1 patient (18%) PR. Of the 8 patients treated with surgical resection, all reported CR (100%). Other than surgical resection, age ≥54 years (median, 54 years; range, 35 to 81 years) was associated with CR (odds ratio = 8.40; 95% confidence interval, 1.27-15.39; p = 0.027). Conclusion Corticosteroids and bevacizumab are commonly utilized treatment modalities with excellent response rate. Our results suggest that patient's age is associated with response rate and could help guide treatment decisions for unresectable symptomatic RN.

Background Breast conserving surgery (BCS) and adjuvant hormonal therapy (HT) without radiation therapy (RT) is an acceptable approach for older women with early stage, estrogen receptor (ER) positive breast cancer. Toxicity and compliance remain issues with HT. Adjuvant RT alone may have better compliance, but its efficacy in the absence of HT is unclear. We aim to assess patterns of adjuvant therapy and survival outcomes among older women with early stage, ER positive (ER+) breast cancer. Methods The National Cancer Data Base (NCDB) was used to identify 130,194 women age ≥65 years with invasive ER+, node negative breast cancer diagnosed between 2004 and 2015. All patients underwent BCS. Kaplan‐Meier survival curves were used to examine overall survival (OS). The association between adjuvant therapy and OS was assessed in multivariable Cox proportional hazards regression models. Results Unadjusted 5/10‐year OS rates were 90.0%/64.3% for HT and RT, 84.2%/54.9% for RT alone, 78.7%/44.5% for HT alone, and 71.6%/38.0% for no treatment; p, In this cohort study of 130,194 women age ≥65 years with invasive ER+, node negative breast cancer who underwent breast conserving surgery, radiation (RT) with hormonal therapy (HT) was associated with the highest 5 and 10‐year survival rates (90.0% and 64.3%, respectively). Compared to patients receiving HT alone, those receiving RT alone had improved unadjusted and adjusted survival rates.

Malignant pleural mesothelioma (MPM) is a relatively rare, but highly lethal cancer of the pleural mesothelial cells. Its pathoge-nesis is integrally linked to asbestos exposure. In spite of recent developments providing a more detailed understanding of the pathogenesis, the outcomes continue to be poor. To date, trimodality therapy involving surgery coupled with chemotherapy and/or radiotherapy remains the standard of therapy. The development of resistance of the tumor cells to radiation and several che-motherapeutic agents poses even greater challenges in the management of this cancer. Ionizing radiation damages cancer cell DNA and aids in therapeutic response, but it also activates cell survival signaling pathways that helps the tumor cells to overcome radiation-induced cytotoxicity. A careful evaluation of the biology involved in mesothelioma with an emphasis on the workings of pro-survival signaling pathways might offer some guidance for treatment options. This review focuses on the existing treatment options for MPM, novel treatment approaches based on recent studies combining the use of inhibitors which target different pro-survival pathways, and radiotherapy to optimize treatment.

BACKGROUND: Surgery may improve survival in malignant pleural mesothelioma (MPM) patients. We examined treatment and survival in black and white surgical MPM patients using the National Cancer Database (NCDB). METHODS: Among patients with pleurectomy/decortication (PD) or extrapleural pneumonectomy (EPP), multivariable logistic regressions were used to evaluate racial differences in surgical extent, additional treatment, and 30-/90-day mortality. Multivariable and propensity matched models were used to assess differences in survival. RESULTS: We identified 2550 patients; 2462 white (96.5%), 88 black (3.5%). Black patients were significantly less likely to receive EPP (OR(adj): 0.36, 95% CI: 0.17–0.78) and trended towards worse 30-/90-day mortality (OR(adj): 1.54, 95% CI: 0.59–4.03; OR(adj): 1.59, 95% CI: 0.80–3.17, respectively). There was no difference in survival (HR(adj): 0.94, 95% CI: 0.71–1.25). Surgery conferred a survival benefit (HR(adj): 0.77, 95% CI: 0.73–0.82), but it varied by race (HR(adj)[white]: 0.76, 95% CI: 0.72–0.81; HR(adj)[black]: 0.93, 95% CI: 0.67–1.29). DISCUSSION: With the limitation of a small proportion of surgically resected black MPM patients in this population-based analysis, black patients were noted to undergo less extensive surgery. Although there was an overall survival benefit noted with surgery, this was not consistent across races, despite trends towards worse short-term mortality in black patients.

Background: As the number of proton centers continues to increase nationwide, the use of proton-based radiotherapy (RT) in the treatment of malignancies is expanding. Randomized trials to assess the efficacy and cardiovascular benefits of proton-based RT compared to photon-based RT in the treatment of breast cancer are underway. However, the data on early toxicity and cosmetic outcomes remains limited. In this study, we report dosimetric data, early toxicity, and patient-reported cosmetic outcomes in breast cancer patients treated with adjuvant proton-based RT after breast-conserving surgery. 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 2019. Patient-reported cosmetic outcomes were graded as excellent, good, fair, and poor. Early toxicity outcomes were graded by the treating physician during the treatment course using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Dose-volume histograms (DVHs) were reviewed to obtain dosimetry data. Results: We identified 21 patients treated with adjuvant proton-based RT. Median age at diagnosis was 58 (range, 26-85). Median body mass index was 26.1 (range, 19.8-58.3). Three patients (14%) had a history of diabetes and three patients (14%) smoking. Three patients (14%) had a history of ipsilateral breast cancer treated with adjuvant RT, and one patient had a history of ipsilateral lung cancer treated with definitive RT. Eleven patients had T1 primary tumors (52%), fifteen (71%) were node-positive, and twelve (57%) had left-sided tumors. Twelve patients (57%) received neoadjuvant and five patients (24%) adjuvant chemotherapy. Median whole breast dose delivered was 46.8Gy (range, 40.0-50.4Gy). Target volumes included the regional lymph nodes in seventeen patients (81%). Seventeen patients (81%) received a lumpectomy boost with a median dose of 10Gy (range, 10-14Gy). 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 367.3cc (range, 0-1172cc) and V110 was 24.1cc (range, 0-321.3cc). Median mean heart dose was 0.39Gy (range, 0-2.6Gy). Median ipsilateral lung V20 was 10% (range, 0-28%) and ipsilateral lung V5 was 28.5% (range, 0.8-55.7%). CTCAE grade 2 dermatitis occurred in 62% and grade 3 in 14% of patients. Grade 2 pain was reported by 33% and grade 3 by 10% of patients. Grade 2 fatigue was reported by 33% of patients. One patient developed acute esophagitis. Median follow-up at the time of cosmetic evaluation was 27 months (range, 5-42 months). Two patients died before cosmetic evaluation. Four patients (21%) reported fair cosmetic outcome and 15 patients (79%) reported good or excellent cosmetic outcome. No poor cosmesis was reported. Conclusions: Adjuvant proton-based radiotherapy after breast-conserving surgery results in low normal tissue exposure compared to typical photon-based plans, particularly when the regional lymphatics are targeted. Proton-based RT is well tolerated with acceptable rates of acute toxicities and a high rate of good-to-excellent patient-reported cosmetic outcomes. Citation Format: Mutlay Sayan, Yin Zhang, Bo Liu, Apar Gupta, Bruce Haffty, Nisha Ohri. Early toxicity and patient-reported cosmetic outcomes in patients treated with adjuvant proton-based radiotherapy after breast-conserving surgery [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-12-20.

The purpose of this study was to evaluate the incidence of clinical lymphedema following adjuvant proton-based radiotherapy (RT) in breast cancer (BC) patients.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.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).The incidence of clinical lymphedema after proton-based RT is comparable to rates reported with photon-based RT with comprehensive nodal coverage.

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.We performed a retrospective review of our institutional database to identify patients who underwent L-Dex U400 measurements. Patients with a score of10 L-Dex units or with an increase of10 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.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). BMI30 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.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.

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.

To evaluate the change in lumpectomy cavity (LPC) volume during hypofractionated radiation (Hypo-RT) and assess the dosimetric benefits of adaptive boost planning on normal tissue exposure in breast cancer patients.Two separate computed tomography (CT) simulation scans were obtained. The first (CT1) was used to plan whole breast irradiation, and the second (CT2) was used to plan LPC boost. LPC boost treatment planning was performed on both CT1 and CT2.Mean LPC volume was significantly smaller on CT2 compared to CT1. LPC boost plan comparison showed significant reductions from CT1 to CT2 in mean heart dose and mean lung dose. Mean volume of tissue receiving 95% of the prescribed boost dose (V95) was lower on CT2 (p=0.001), as was V80 (p0.001) and V50 (p0.001).LPC volume can change significantly during Hypo-RT. Adaptive LPC boost planning can be considered to reduce normal tissue exposure.

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).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.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).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.

Adjuvant radiation therapy is often delivered after breast cancer surgery, both in the post-lumpectomy and post-mastectomy settings. Standard fractionation whole breast irradiation (SF-WBI), which is typically delivered over 5-7 weeks, was previously considered the standard of care. More recent data has helped to establish hypofractionated whole breast irradiation (HF-WBI), which consists of a 3-4 week regimen, as a new standard of care. This article provides an overview of the major randomized trials that support the routine use of HF-WBI for the majority of patients undergoing breast-conserving surgery for early-stage breast cancer. Newer data on the use of a hypofractionated approach in the post-mastectomy setting, as well as ongoing randomized trials addressing this topic, are also discussed.

Purpose To report 5-year outcomes of a phase 2 trial of hypofractionated whole breast irradiation (HF-WBI) completed in 3 weeks, inclusive of a sequential boost. Methods and Materials Women with stage 0-IIIA breast cancer (ductal carcinoma in situ through T2N2a) were enrolled on a prospective, phase 2 trial of accelerated HF-WBI. We delivered a whole breast dose of 36.63 Gy in 11 fractions of 3.33 Gy, with an equivalent dose to the regional nodes when indicated, followed by a tumor bed boost of 13.32 Gy in 4 fractions of 3.33 Gy over a total of 15 treatment days. The primary endpoint was locoregional control; secondary endpoints included acute/late toxicity and physician-assessed and patient-reported breast cosmesis. Results Between 2009 and 2017, we enrolled 150 patients, of whom 146 received the protocol treatment. Median age was 54 years (range, 33-82) and median follow-up was 62 months. Patients with higher-risk disease comprised 59% of the cohort, including features such as young age (33% ≤50 years), positive nodes (13%), triple-negative disease (11%), and treatment with regional nodal irradiation (11%) and/or neoadjuvant/adjuvant chemotherapy (36%). Five-year estimated locoregional and distant control were 97.7% (95% confidence interval [CI], 93.0%-99.3%) and 97.9% (95% CI, 93.6%-99.3%), respectively. Five-year breast cancer–specific and overall survival were 99.2% (95% CI, 94.6%-99.9%) and 97.3% (95% CI, 91.9%-99.1%), respectively. Acute/late grade 2 and 3 toxicities were observed in 30%/10% and 1%/3% of patients, respectively. There were no grade 4 or 5 toxicities. Physicians assessed breast cosmesis as good or excellent in 95% of patients; 85% of patients self-reported slight to no difference between the treated and untreated breast. Conclusions Our phase 2 trial offers one of the shortest courses of HF-WBI; at 5 years of follow-up there continues to be excellent locoregional control and low toxicity with favorable cosmetic outcomes in a heterogeneous cohort of patients.

Background To investigate the setup uncertainties and to establish an optimal imaging schedule for the prone-positioned whole breast radiotherapy. Methods Twenty prone-positioned breast patients treated with tangential fields from 2015 to 2017 were retrospectively enrolled in this study. The prescription dose for the whole breast treatment was 266 cGy × 16 for all of the patients and the treatments were delivered with the SSD setup technique. At every fraction of treatment, patient was firstly set up based on the body localization tattoos. MV portal imaging was then taken to confirm the setup; if discrepancy (> 3 mm) was found between the portal images and corresponding plan images, the patient positioning was adjusted accordingly with couch movement. Based on the information acquired from the daily tattoo and portal imaging setup, three sets of data, named as weekly imaging guidance (WIG), no daily imaging guidance (NIG), and initial 3 days then weekly imaging guidance (3 + WIG) were sampled, constructed, and analyzed in reference to the benchmark of the daily imaging guidance (DIG). We compared the setup uncertainties, target coverage (D95, Dmax), V5 of the ipsilateral lung, the mean dose of heart, the mean and max dose of the left-anterior-descending coronary artery (LAD) among the 4 imaging guidance (IG) schedules. Results Relative to the daily imaging guidance (IG) benchmark, the NIG schedule led to the largest residual setup uncertainties; the uncertainties were similar for the WIG and 3 + WIG schedules. Little variations were observed for D95 of the target among NIG, DIG and WIG. The target Dmax also exhibited little changes among all the IG schedules. While V5 of the ipsilateral lung changed very little among all 4 schedules, the percent change of the mean heart dose was more pronounced; but its absolute values were still within the tolerance. However, for the left-sided breast patients, the LAD dose could be significantly impacted by the imaging schedules and could potentially exceed its tolerance criteria in some patients if NIG, WIG and 3 + WIG schedules were used. Conclusions For left-side whole breast treatment in the prone position using the SSD treatment technique, the daily imaging guidance can ensure dosimetric coverage of the target as well as preventing critical organs, especially LAD, from receiving unacceptable levels of dose. For right-sided whole breast treatment in the prone position, the weekly imaging setup guidance appears to be the optimal choice.

BackgroundAccess to cancer care is a problem that continues to plague refugees displaced from their home countries. The turbulent political crisis in Syria, which has led to millions of refugees seeking asylum in Turkey, merits further attention. We aimed to study the rate of utilization of radiation therapy among Syrian refugees with cancer living in Turkey in an attempt to identify the contributing factors predictive of non-compliance with prescribed RT.MethodsIn this retrospective review of 14 institutional databases, Syrian refugee patients in Turkey with a cancer diagnosis from January 2015 to December 2018 who were treated with RT were identified. The demographic data, treatment compliance rates, and toxicity outcomes in these patients were surveyed. Variable predictors of noncompliance such as age, gender, diagnosis, geographic location, treatment length, and toxicity were studied. The association between these variables and patient noncompliance was determined.ResultsWe identified 10,537 patients who were diagnosed with cancer during the study period, of whom 1010 (9.6%) patients were treated with RT. Breast cancer (30%) and lung cancer (14%) were the most common diagnoses with up to 68% of patients diagnosed at an advanced stage (Stage III, IV). 20% of the patients were deemed noncompliant. Treatment with concurrent chemoradiotherapy (OR 1.61, 95% CI 1.06 – 2.46, p = 0.023) and living in a refugee camp (OR 3.62, 95% CI 2.43 – 5.19, p < 0.001) were associated with noncompliance. Age, gender and treatment length were not significantly associated with noncompliance.ConclusionsNoncompliance with radiotherapy among Syrian refugees in Turkey remains an area of concern with a multitude of factors contributing to these alarming numbers. Further studies to better ascertain the finer nuances of this intricately complex problem and a global combination of efforts can pave the way to providing a solution.

Purpose To provide an overview of the major randomized trials that support the use of hypofractionated post-mastectomy radiation therapy for locally advanced breast cancer patients. Methods and Materials PubMed was systematically reviewed for publications reporting use of of hypofractionated radiation therapy in patients requiring post-mastectomy radiation. Results Standard fractionation, which is typically delivered over 5 to 7 weeks, is considered the standard of care in setting of post-mastectomy radiation therapy (PMRT). Modern data has helped to establish hypofractionated whole breast irradiation, which consists of a 3- to 4-week regimen, as a new standard of care for early-stage breast cancer. Hypofractionated whole breast irradiation has also laid the groundwork for the exploration of a hypofractionated approach in the setting of hypofractionated post-mastectomy radiation therapy. Conclusions While standard fractionation remains the most commonly utilized regimen for PMRT, recently published trials support the safety and efficacy of a hypofractionated approach. Ongoing trials are further investigating the use of hypofractionated PMRT.

Hypofractionated radiotherapy (Hypo-RT) is now considered the standard of care for the majority of patients receiving whole-breast irradiation (WBI). However, there are few data on the use of Hypo-RT in human epidermal growth factor receptor 2 (HER2)-positive patients receiving concurrent anti-HER2 therapy. In this study, we sought to examine patterns of WBI in HER2-positive patients.Using the National Cancer Data Base, we identified women with nonmetastatic HER2-positive breast cancer diagnosed between 2010 and 2015 who received WBI. The Hypo-RT group was defined as those receiving 21 or fewer fractions. All other patients were in the conventional radiotherapy (RT) group. Multivariate logistic regression was used to identify predictors of Hypo-RT utilization. Five-year overall survival was estimated by the Kaplan-Meier method.The study included 15,776 patients, of whom 17.7% received Hypo-RT. The rate of Hypo-RT utilization increased from 7.4% in 2010 to 29.3% in 2015 (P = .004). Predictors of Hypo-RT use included older age (≥60 vs. 60 years), higher median income quartile, further distance from the treatment facility (50 vs. ≤50 miles), treatment at an academic facility, and later year of diagnosis. Unadjusted 5-year overall survival rates were similar among patients who received Hypo-RT and conventional RT (93.9% vs. 95.2%, P = .26). After adjusting for patient, facility, and tumor variables, Hypo-RT was not significantly associated with survival.Although Hypo-RT was not commonly delivered in patients with HER2-positive breast cancer, the utilization rate quadrupled over the study period. Multiple socioeconomic and clinical predictors of Hypo-RT receipt were identified. Adjuvant RT regimen was not significantly associated with overall survival.

Adjuvant whole-breast irradiation (WBI) after lumpectomy has been an established standard of care for decades. Standard-fractionation WBI delivered over 5 to 7 weeks can achieve durable tumor control with low toxicity but can be inconvenient for patients and cost ineffective. Hypofractionated WBI can be completed in 3 to 4 weeks and, based on long-term randomized data, is the preferred standard of care in select patients. Accelerated partial-breast irradiation can be delivered using even shorter treatment regimens. Although the available data on accelerated partial-breast irradiation is more limited, early results suggest it is an effective alternative to WBI in select patients.

BACKGROUND High-level evidence is lacking to guide treatment decisions about postmastectomy radiation therapy (PMRT) in patients who have breast cancer with 1 to 3 positive lymph nodes who receive contemporary systemic therapies, leading to potential variations in PMRT delivery. The objective of this study was to examine nationwide trends in PMRT use in this group. METHODS The National Cancer Data Base (NCDB) was used to identify 93,372 women who had T1-T2N1 breast cancer diagnosed between 2003 and 2012. Patients who received neoadjuvant chemotherapy or radiation therapy (RT) and those who had bilateral breast cancers were excluded. Time trends were evaluated using the Cochrane-Armitage test and correlated the receipt of PMRT with various patient demographic, facility, clinicopathologic, and treatment variables using multivariable logistic regression. A second analysis was performed for patients who were diagnosed during 2010 and included radiation oncologist density as an additional covariate. P values

To analyze postmastectomy radiation therapy (PMRT) usage and its association with overall survival (OS) in breast cancer patients with pathologically positive lymph nodes after neoadjuvant chemotherapy (NAC).Using the National Cancer Database, we identified women with nonmetastatic breast cancer diagnosed from 2004 to 2013 who had received NAC and undergone mastectomy with macroscopic pathologically positive lymph nodes. Joinpoint regression models were used to assess temporal trends in annual PMRT usage. Multivariable regression models were used to identify factors associated with PMRT use. A time-dependent Cox model was used to evaluate the predictors of mortality.The study included 29,270 patients, of whom 62.5% received PMRT. PMRT was markedly underused among all nodal subgroups, in particular, among ypN2 (68.4%) and ypN3 (67.0%) patients. Hispanic patients and those with Medicaid or Medicare insurance were less likely to receive PMRT than were non-Hispanics and patients with other insurance carriers. The adjusted 5-year OS rates were similar in ypN1 and ypN2 patients with or without PMRT but were significantly greater in ypN3 patients receiving PMRT (66% vs 63%; P=.042). On multivariable analysis, PMRT was associated with improved survival only among ypN3 patients after adjusting for patient, facility, and tumor variables (multivariable hazard ratio 0.85; 95% confidence interval 0.74-0.97).A considerable portion of breast cancer patients with advanced residual nodal disease after NAC did not receive appropriate adjuvant radiation. We also found socioeconomic disparities in national PMRT practice patterns. Patients with ypN3 disease might derive a survival benefit from PMRT.

Purpose Positive margins after definitive resection in gastric adenocarcinoma are associated with inferior outcomes. There are few randomized data to guide optimal adjuvant therapy after positive margins. Methods Using the National Cancer Database, we identified 24,619 nonmetastatic gastric adenocarcinoma patients who received diagnoses from 2004 to 2013 and underwent definitive resection to analyze for predictors of positive surgical margins. Of these patients, 2754 had positive margins (11.2%). Multivariate prevalence ratios were used to determine predictors. Survival analyses were performed with a Cox proportional hazards model by use of several methods of propensity score analysis. Results Increasing T and/or N category, high grade, and lymphovascular invasion predicted higher rates of positive margins. Asian race, treatment at an academic center, and robotic surgery predicted lower rates of positive margins. Among positive-margin patients with adjuvant treatment (n=1021), with a median follow-up period of 55 months, age, comorbidity score, nodal disease, and T4 disease predicted for worse overall survival (OS). Treatment at an academic center was associated with improved OS. Use of adjuvant concurrent chemoradiation therapy (CCRT) was associated with higher OS compared with chemotherapy alone after positive margins (hazard ratio, 0.72; 95% confidence interval, 0.58-0.91; P=.005) after propensity matching adjusting for predictors of OS. The 2-year and 3-year OS for positive-margin patients with chemotherapy alone was 43% and 29%, respectively, compared with 53% and 38%, respectively, with adjuvant CCRT. The log-rank P value for survival was .0015. Conclusions Stage, race, treatment center, and surgery approach predict for margin status after resection. Adjuvant CCRT after positive margins is associated with improved OS after accounting for available clinical variables.

The objectives of this study were to analyze rates of radiation therapy (RT) utilization for malignant pleural mesothelioma (MPM) and evaluate the association between RT and overall survival (OS). The National Cancer Data Base (NCDB) was queried to identify patients with non-metastatic MPM diagnosed between 2004 and 2013. RT was defined as receipt of 40-65Gy of external beam radiation therapy to the chest wall, lungs, or pleura. Multivariable logistic regression was performed to identify predictors of RT receipt. OS was estimated using the Kaplan-Meier method. Propensity score matching was performed to verify the effect of RT on OS. Among 14,090 MPM patients, 3.6% received RT. Younger age, lower co-morbidity score, private insurance, surgical resection, and receipt of chemotherapy were associated with increased RT utilization. Patients who received RT had higher crude 2 and 5-year OS rates (33.9 and 12.6%, respectively) compared to patients who did not (19.5 and 5.3%, respectively; p

Purpose: Radiotherapy for patients with non-metastatic human epidermal growth factor receptor 2 (HER2) positive breast cancer is commonly administered concurrently with adjuvant trastuzumab. However, there is limited data on the use of concurrent trastuzumab and hypofractionated radiotherapy (Hypo-RT), which is now standard of care for the majority of women receiving whole breast irradiation. In this study, we compared acute cardiotoxicity rates in HER2-positive breast cancer patients treated with concurrent trastuzumab and Hypo-RT or conventionally fractionated radiotherapy (Conv-RT). Methods: We performed a review of our institutional database to identify HER2-positive breast cancer patients treated with trastuzumab and Hypo-RT or Conv-RT from 2005 to 2018 who underwent serial cardiac Left Ventricular Ejection Fraction (LVEF) evaluation. Decrease in LVEF was assessed by either echocardiography (ECHO) or multiple gated acquisition (MUGA) scan performed at baseline and every 3 months during trastuzumab therapy. Significant LVEF decline was defined as an absolute decrease in LVEF of ≥10% below the lower limit of normal or ≥16% from baseline value. Results: We identified 41 patients treated with Hypo-RT and 100 patients treated with Conv-RT. Median follow-up was 32 months (range, 13-90 months). Baseline median LVEF was 62% (range, 50-81%) in Hypo-RT group and 64% (range, 51-76%) in Conv-RT group (p = 0.893). Final median LVEF was 60% (range, 50-75%) in both groups. Three patients (7%) in Hypo-RT and five (5%) in Conv-RT group developed significant asymptomatic LVEF decline (p = 0.203). There was no significant difference in mean heart dose in patients who developed significant asymptomatic LVEF decline vs. those who did not in Hypo-RT (p = 0.427) and Conv-RT (p = 0.354) groups. No symptomatic congestive heart failure was reported in either group. Conclusions: The rate of asymptomatic LVEF decline in patients receiving concurrent trastuzumab and Hypo-RT was low (7%) and was similar to the rate observed in patients receiving Conv-RT. Longer follow-up is warranted to assess late cardiotoxicity.

Purpose: Renal cell carcinoma (RCC) and melanoma have been considered `radioresistant' due to the fact that they do not respond to conventionally fractionated radiation therapy. Stereotactic radiosurgery (SRS) provides high-dose radiation to a defined target volume and a limited number of studies have suggested the potential effectiveness of SRS in radioresistant histologies. We sought to determine the effectiveness of SRS for the treatment of patients with radioresistant brain metastases. Materials and Methods: We performed a retrospective review of our institutional database to identify patients with RCC or melanoma brain metastases treated with SRS. Treatment response were determined in accordance with the Response Evaluation Criteria in Solid Tumors. Results: We identified 53 radioresistant brain metastases (28\% RCC and 72\% melanoma) treated in 18 patients. The mean target volume and coverage was 6.2 +/- 9.5 mL and 95.5\% +/- 2.9\%, respectively. The mean prescription dose was 20 +/- 4.9 Gy. Forty lesions (75\%) demonstrated a complete/partial response and 13 lesions (24\%) with progressive/stable disease. Smaller target volume (p < 0.001), larger SRS dose (p < 0.001), and coverage (p = 0.008) were found to be positive predictors of complete response to SRS. Conclusion: SRS is an effective management option with up to 75\% response rate for radioresistant brain metastases. Tumor volume and radiation dose are predictors of response and can be used to guide the decision-making for patients with radioresistant brain metastases.

Background: Triple negative breast cancer (TNBC) is an aggressive subtype accounting for 15% of all breast cancer cases. It is characterized by larger tumor size, higher grade, early peak of recurrence, and a worse 5-year overall survival rate compared to other breast cancer subtypes. Chemotherapy serves as the backbone for the treatment of metastatic TNBC. Treatment with immunotherapy in combination with Abraxane, a taxane-based chemotherapy, is of benefit only in PD-L1 positive tumors, which represents a minority of the patients. Pelareorep, a proprietary isolate of the unmodified, replication competent reovirus type 3 Dearing (T3D), has been shown to upregulate PD-L1 expression in tumor and inflammatory cells and downregulate intra-tumoral regulatory T-cells in the tumor microenvironment in pre-clinical and early clinical studies. Retifanlimab is a PD-1 inhibitor currently in development. The rationale for this clinical study is that the administration of pelareorep will prime the tumor microenvironment for enhanced tumor response to PD-1 inhibitor retifanlimab.Trial design: This is a phase II multi-site single-arm clinical trial to study the combination of PD-1 inhibitor retifanlimab and the oncolytic virus Pelareorep in metastatic triple negative breast cancer who have progressed on chemotherapy. Eligible patients will receive pelareorep 4.5x1010 TCID50 /day IV, on Days 1, 2, 15 and 16 and retifanlimab 500mg IV on day 3 of every 28-day cycle until disease progression or unacceptable toxicity. Patient will be monitored clinically and radiologically for response to treatment. Tumor tissue, stool and blood samples will be collected while on treatment to evaluate changes in PD-L1 expression, gut microbiome and inflammatory cells induced by the study drugs. (ClinicalTrials.gov Identifier: NCT04445844) Eligibility criteria: Eligible patients will include premenopausal/postmenopausal women with metastatic TNBC who have previously received 1-2 prior lines of chemotherapy in the metastatic setting. ECOG PFS 0-2. Specific aims: Primary endpoint will be objective response rate (ORR) and safety, determined by the number, frequency, duration, and severity of AEs using CTCAE v5.0. The secondary end-points will be progression free survival (PFS), overall survival (OS) and duration of response (DOR) and quality of life measures using EORTC QLQ-C30. Statistical methods: Simon’s optimal 2-stage design will be used to calculate sample size. In the first stage, 14 patients will be accrued. If there are 1 or fewer responses in these 14 patients, the study will be stopped. Otherwise, 11 additional patients will be accrued for a total of 25. The null hypothesis will be rejected if 4 or more responses are observed in 25 patients. The first 6 patients will be enrolled in a staggering interval for the safety run-in phase of the study. Accrual: The study will enroll up to 25 patients at Rutgers Cancer Institute of New Jersey and Ohio State University Comprehensive Cancer Center Contact information: Mridula George, MD Email: mridula@cinj.rutgers.edu Citation Format: Mridula George, Nicole Williams, Maryam Lustberg, Coral Omene, Nancy Chan, Nisha Ohri, Maria Kowzun, Lindsay Potdevin, Firas Eladoumikdachi, Shicha Kumar, Robert Wesolowski, Grey Wilkinson, Danielle Tang, Sinae Kim, Shridar Ganesan, Bruce Haffty, Deborah Toppmeyer. Irene study: Phase 2 study of incmga00012 (retifanlimab)and the oncolytic virus pelareorep in metastatic triple negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-32-02.