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epirubicin, fulvestrant, medroxyprogesterone and megestrol acetate, pertuzmuab and palbociclib. Conclusion This review of the literature could help oncologists in their current practice. However, clinical trials bringing a higher level of evidence are needed to establish robust guidelines with newer drugs. Big data analysis on drug- safety follow-up will contribute to validate this guidelines. EP-1292 Impact of adjuvant trastuzumab on locoregional recurrence in HER2-overexpressed breast cancer S.H. Jeon 1 , K.H. Shin 1 , K. Kim 2 , I.A. Kim 3 1 Seoul National University Hospital, Radiation Oncology, SEOUL, Korea Republic of 2 Ewha Womans University Hospital, Radiation Oncology, SEOUL, Korea Republic of 3 Seoul National University Bundang Hospital, Radiation Oncology, Seungnam, Korea Republic of Purpose or Objective To examine whether adjuvant trastuzumab reduces locoregional recurrence in human epidermal growth factor-2 (HER-2) overexpressed breast cancer receiving We retrospectively included 520 patients with HER-2 overexpressed breast cancer who received radical surgery followed by adjuvant radiotherapy and cytotoxic chemotherapy from 2003 to 2011. Adjuvant trastuzumab was administered in 286 patients. Propensity score matching was conducted to compare trastuzumab-treated and –not-treated cohorts. Results Median follow-up duration was 7.1 years. Positive estrogen/progesterone receptor, advanced stage, and lymphatic invasion were more common in trastuzumab- treated cohort (all p<.10). Propensity score matching yielded 166 matched pairs of patients with no significantly different clinical factors (all p>.10). Improved 7-year locoregional control rate (LRC) was observed in trastuzumab-treated cohort (96.2% vs 91.5%, p=.04). On multivariate analysis, negative hormone receptor status (p=.019) and positive lymph node ratio ≥ 0.25 (p=.016) were identified as significant risk factors of poor LRC. Adjuvant trastuzumab significantly reduced locoregional recurrence in patients with 1 or 2 risk factors (7-year LRC = 95.7% vs 86.2%, p=.03); however, the benefit of adjuvant trastuzumab was not significant in patients with no risk factors (7-year LRC = 96.3% vs 100%, p=.22). Conclusion Adjuvant trastuzumab seems to prevent locoregional recurrence in HER-2 overexpressed breast cancer receiving adjuvant radiotherapy and cytotoxic chemotherapy, especially when the risk factors are present. EP-1293 Lymphovascular invasion as a negative prognostic factor for triple-negative breast cancer Y.S. Choi 1 1 Busan Paik hospital, Radiation Oncology, Busan, Korea Republic of Purpose or Objective This study aimed to evaluate the prognostic effects of lymphovascular invasion (LVI) in triple-negative breast cancer (TNBC) patients who underwent surgical resection. Material and Methods A total of 63 non-metastatic TNBC patients who underwent surgical resection were retrospectively investigated from 2007 to 2016 in Busan Paik Hospital. Pathological tests revealed that 12 patients (19.0%) had adjuvant radiotherapy. Material and Methods

（ 3536.45 cGy ） and F-IMRT （ 3574.05 cGy) were not significantly different. After a sub-analysis according the location of tumor bed, patients with tumor bed located in the inner quadrant received higher dose than those with medial and outer quadrants. The median D mean attained 4831cGy, 4730.5cGy and 4702cGy in the inner group with 3D-CRT, F-IMRT and I-IMRT, respectively. After separating the three techniques for further analysis, the median D mean was highest in ICS3, followed by ICS2 and lowest in ICS1 for all the three techniques. For 3D-CRT and F-IMRT, the BMI and the breast separation affected the incidental dose to IMC. For I-IMRT, the distance from isocenter to pleura and the thoracic index could affect the incidental All three techniques failed to attain an adequate dose to cure subclinical disease, and there were no significant differences among the three techniques. It is risky to avoid internal mammary node irradiation (IMNI) using any of the three techniques during whole-breast radiotherapy (WBRT) in women with indications for elective IMNI. However, for patients with tumor bed in the inner quadrants, the ICS3 received meaningful incidental irradiation dose. For this group, large sample studies were needed to confirm whether the ICS3 could avoid irradiation. And in systematic therapy era, whether the incidental dose for ICS1-3 could meet clinical acquirements needs further follow-up. EP-1291 Clinical guidelines for breast cancer drugs and radiotherapy based on combination safety data G. Boulle 1 , A. Bayle 2 , E. Deutsch 1 , M. Arnedos 2 , S. Rivera 1 1 Gustave Roussy Cancer Campus, Radiation oncology, Villejuif, France 2 Gustave Roussy Cancer Campus, Oncology, Villejuif, France Purpose or Objective Breast cancer is the most common cancer among women in the world with an incidence of more of 1.5 Million of new cases each year. Life expectancy in metastatic breast cancer is increasing due to the increase in therapeutic arsenal. Therefore raises the dilemma to pursue or withhold systemic treatments during palliative radiotherapy especially due to the risk of radio sensitization and consequent potential toxicities. Material and Methods We reviewed, based on the level of proof available in the literature, for each major drug used in metastatic breast cancer whether there is a need to adapt the treatment when a concurrent normofractioned, hypofractionated or stereotactic radiotherapy is needed for palliation. For each drug, publications with the highest level of evidence were selected. to propose guidelines on maintenance, adaptation and discontinuation of systemic treatments when radiotherapy is needed. Results A total of 75 articles were selected in the final analysis: 42, 12 and 19 for chemotherapy molecules, hormone therapy and targeted therapies respectively. Twenty six molecules were selected: 3 alkylating agents, 3 anti- metabolites, 3 topoisomerase inhibitors and 4 spindle poisons, 4 hormone therapies and 7 targeted therapies. In view of the data, concomitant drug and radiotherapy combination appears acceptable based on available safety data for carboplatin, cisplatin, xeloda, etoposide, weekly paclitaxel, vinorelbine , anastrozol, letrozol and trastuzumab. Concomitant drug and radiotherapy combination appears not advisable based on available safety data for gemcitabine, docetaxel, methotrexate, eribulin tamoxifen, bevacizumab, trastuzumab- emtanzine. Concomitant drug and radiotherapy combination should be cautious based on limited available safety data for cyclophosphamide, doxorubicin, dose to IMC. Conclusion