PO100 IMRT-SIB FOR LOCALLY ADVANCED INOPERABLE BREAST CANCER PATIENTS

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Abstracts / The Breast 24 S3 (2015) S21–S75

negative (ER+, HER2-, high Ki67 or low PR+), luminal B HER2-positive (ER+, HER2+, any PR/Ki67), HER2-enriched (HER2+, ER-) and triple negative (ER-, PR-, HER2-). Prognostic groups of recursive partitioning analysis (RPA), graded prognostic assessment (GPA), breast GPA and simple survival score (including Karnofsky performance status (PS) and extracranial metastases) for patients with BC BM (SS-BM) were compared. Overall survival (OS) was calculated using the Kaplan-Meier method. Cox regression model was used to evaluate prognostic values of PI, clinical and biological characteristics. Results: Median age at BC diagnosis, diagnosis of any metastatic disease and BM diagnosis was 51.7, 56.6 and 58.6 years, respectively. At time of BM diagnosis, 114 (85.7%) patients had extracranial disease. In addition to WBRT, 27 (20.3%) patients had BM surgery. The median OS from BM diagnosis was 8.3 months (CI 95%, 5.4-11.2). Asymptomatic patients at time of WBRT had longest median OS of 21.0 months (CI 95% 9.2-32.7, p<0.0005). WBRT improved BM symptoms in 85 (64%) patients, which was significantly associated with improved median OS (12.3 versus 3.6 months, p<0.0005). 26 (19.5%) patients had luminal A, 18 (13.5%) luminal B HER2-, 31 (23.3%) luminal B HER2+, 20 (15.0%) HER2-enriched and 18 (13.5%) triple negative tumors at BC diagnosis. Molecular characteristics of 20 (15.0%) tumors were missing. Longest median OS of 13.5 (CI 95%, 8.2-18.7) and 13.0 (CI 95%, 2.2-23.9) months was seen in luminal B HER2+ and HER2-enriched tumors, respectively. OS difference between molecular subtypes was not statistically significant (p=0.070). In multivariate analyses, better PS at time of WBRT (p<0.0005), BM surgery (p=0.001), systemic hormonal therapy within 3 months before or after WBRT (p=0.024), good prognostic groups of Breast GPA (p=0.003) and SS-BM (p=0.027) were all significantly associated with OS improvement. Conclusion: Patients with BM have different outcomes after WBRT, regarding symptoms improvement and OS. Breast GPA and SS-BM seem to be useful tools for personalised cancer treatment decisions in palliative care for BC patients with BM.

PO100 IMRT-SIB FOR LOCALLY ADVANCED INOPERABLE BREAST CANCER PATIENTS Dorota Gabrys1, Roland Kulik1, Agnieszka Namysł-Kaletka1, Iwona Wzietek1, Karolina Widera2, Krystyna Trela-Janus1 1 Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Radiotherapy, Gliwice, Poland; 2Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Outpatient Clinic, Gliwice, Poland Radiobiological and clinical data suggest that higher dose per fraction with shortening overall treatment time in breast cancer patients may enhance locoregional control. This, ethics approved, prospective study was designed to evaluate the technical feasibility, toxicity and early results of simultaneous integrated boost (SIB) for locally advanced, breast cancer patients. Eighteen women (8 right; 10 left sided) received radiotherapy with SIB applying various dose levels in 30 fractions. Doses were individualized according to the stage of the disease. The regional lymph nodes received 49.8-60 Gy, df 1.66-2 Gy, metastatic lymph nodes received 66-69.9 Gy, df 2.2-2.33 Gy, breast with chest wall was irradiated with a dose 49,8-60 Gy, the whole breast to 60Gy, and the highest dose was delivered to the breast tumour 69.9 Gy. Early toxicity and results were prospectively recorded using CTCAE 4.03, QLQ 30, QLQ Br23, and Lent Soma scale. All patients underwent planning CT or FDG PET-CT. The majority (13 patients) were treated with the use of Clinac IMRT-SIB, 5 patients were treated with Tomo-SIB. The median age was 59 years (range 37 – 78). Median tumor size was 6 cm (range 1-12 cm). Almost all (13) patients presented with clinical stage IIIB of the disease, one patient with IIIA, two with IIIC. Two patients in stage IIA were not qualified to surgery, one was not suitable for resection due to medical conditions, the second did not agree for a surgery. All patients received chemotherapy, 11 patients FAC only, remaining various combinations with taxanes. Ten patients were treated with hormonal therapy, the majority of them (8 patients) were treated with tamoxifen. The mean

dose to the ipsilateral lung was 16 Gy (range 12.9 - 20.7). The percentage of lung receiving >5Gy was 74.4, >10Gy - 50.3, >20Gy - 25.6. The mean heart dose was 9.6 Gy (range 5.4 - 16.9) and V5Gy was 64.1, V10Gy 28.9, V30Gy - 4.9. There was significant decrease in WBC (median 6.2 vs. 4.9 × 103/ul; p-0.03), PLT (235 vs. 184 × 103/ul; p-0.01) before and after radiotherapy. RBC and Hb did not significantly decrease. The maximum Grade 3 early skin toxicity by the end of treatment was present only in two patients. No Grade 4 toxicities were observed. The maximum Grade 2 fatigue, Grade 1 dysphagia, Grade 1 pain with swallowing were recorded. The early skin toxicity resolved in all patients evaluated one month after finishing the treatment. Conclusions: This 6-week course of definitive radiotherapy using SIB technique showed to be feasible and was associated with acceptable early skin toxicity. Long-term follow-up data are needed to assess late toxicity and clinical outcomes.

PO101 PROGNOSTIC FACTORS AFTER GAMMA KNIFE RADIOSURGERY IN BREAST CANCER PATIENTS WITH BRAIN METASTASES Shoko Hayama3, Osamu Nagano2, Naohito Yamamoto1, Takeshi Nagashima3, Rikiya Nakamura1, Masaaki Sakamoto4 1 Chiba Cancer Center, Division of Breast Surgery, Chiba City, Japan; 2Chiba Cerebral and Cardiovascular Center, Gamma Knife House, Ichihara City, Chiba, Japan; 3Chiba University, General Surgery Department, Chiba City, Japan; 4Kameda Medical Center, Division of Breast Surgery, Kamogawa City, Chiba, Japan Backgrounds and Aim: Gamma knife radiosurgery (GK) is one of the effective treatment options for brain metastases (BM) from breast cancer. Some reports showed its efficacy on prolongation of survival. However, the prognostic factors associated with good prognosis in BM patients remains unclear. Therefore, we set out to clarify these factors. Materials and Methods: We retrospectively analyzed the data of 70 breast cancer patients with BM who were treated with GK in our institution from January 2005 to December 2014. We exploratory examine the relationships between clinico-pathological factors and overall survival (OS) after GK. Clinico-pathological factors included age at initial diagnosis, performance status (PS), neurocognitive symptoms, the number and volume of BM lesions, WBRT history, craniotomy history, time to BM from the primary diagnosis, time to BM from the first time of recurrence, the number of systemic therapies after GK, and breast cancer subtypes. Results: The median age at initial diagnosis was 48 (range 28-75). The median KPS at diagnosis of BM was 90 (60-100). Fifty-two cases (74%) had neurocognitive symptoms. The median number of BM was 3 lesions (1-32). Twenty-four cases (34%) had a history of craniotomy and 18 cases (26%) had WBRT. The median period from primary diagnosis to BM was 54 months (0-330) and the median period from the first recurrence to BM was 14 months (0-171). The median number of systemic therapy after GK was 1 regimen (0-7). In breast cancer subtypes, Estrogen receptor (ER) positive/Human epidermal growth factor receptor 2 (HER2) negative, ER (+)/HER (+), ER(-)/HER2(+), ER(-)/HER2(-), were 21, 14, 17, 18 cases, respectively. The cases with PS2, neurocognitive symptoms, WBRT history, or the number of GK1 had significant relationships with poor OS after GK. The OS after GK in ER(+)/HER2(+) group were significantly better than other subtypes (1-year survival rate was 85%, p <0.05). Conclusions: Our study showed that patients with no symptoms and good PS at BM diagnosis demonstrated good prognosis after GK.

PR102 STERNAL RECURRENCE IN TREATED PATIENTS OF ADVANCED STAGE CARCINOMA BREAST - AN EMERGING ENTITY Divyesh Kumar VCSGGMS&RI, Radiation Oncology, Srinagar, India