Breast Conserving Surgery in Combination With Targeted Intraoperative Radiotherapy Compared to Mastectomy for In-breast-tumor-recurrence.

BACKGROUND/AIM: Mastectomy is the standard treatment of in-breast-recurrence of breast cancer after breast conserving surgery (BCS) and external beam radiation therapy (EBRT). In selected cases, it is possible to preserve the breast if targeted intraoperative radiotherapy (TARGIT-IORT) can be given during the second lumpectomy. This is a comparative analysis of overall survival and quality of life (QoL). PATIENTS AND METHODS: Patients in our database with in-breast-recurrence and either mastectomy or BCS and TARGIT-IORT were included. Identified patients were offered participation in a prospective QoL-analysis using the BREAST-Q questionnaire. The cohorts were compared for confounding parameters, overall survival, and QoL. RESULTS: Thirty-six patients treated for in-breast-recurrence were included, 21 had received a mastectomy and 16 patients had received BCS with TARGIT-IORT. Mean follow-up was 12.8 years since primary diagnosis and 4.2 years since recurrence. Both groups were balanced regarding prognostic parameters. Overall survival was numerically longer for BCS and TARGIT-IORT, but the numbers were too small for formal statistical analysis. No patient had further in-breast-recurrence. Psychosocial and sexual wellbeing did not differ between both groups. Physical wellbeing was significantly superior for those whose breast could be preserved (p-value=0.021). Patient-reported incidence and severity of lymphedema of the arm was significantly worse in the mastectomy group (p=0.007). CONCLUSION: Preserving the breast by use of TARGIT-IORT was safe with no re-recurrence and no detriment to overall survival in our analysis and led to a statistically significant improvement in physical wellbeing and incidence of lymphedema. These data should increase the confidence in offering breast preservation after in-breast-recurrence of breast cancer.

Targeted Intraoperative Radiotherapy Tumour Bed Boost During Breast Conserving Surgery after Neoadjuvant Chemotherapy in HER2 Positive and Triple Negative Breast Cancer.

INTRODUCTION: Targeted intraoperative radiotherapy (TARGIT - IORT) as a tumour bed boost after breast conserving surgery is well established for women with early breast cancer. A previous study from our group shows a beneficial effect of TARGIT-IORT on overall survival (OS) but not disease-free survival (DFS) after neoadjuvant chemotherapy compared to an external boost suggesting a potential non-inferiority of TARGIT-IORT. In this study, we present results regarding the high-risk subset of patients (i.e. with triple negative (TN) and HER2 positive tumours) from this cohort. METHOD: In this non-randomized cohort study involving patients with HER2 positive (n= 28) and triple negative (n=42) tumours after NACT we compared outcomes of 40 patients with tumour bed boost applied with TARGIT IORT during lumpectomy versus 30 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Rates of DFS and OS were compared. RESULTS: Median follow up was 49 months. In comparison of TARGIT-IORT vs. EBRT 5-year Kaplan- Meier estimates of OS showed no significant difference among patients with HER2 positive tumours (100% vs. 91.7%, log rank p = 0.22). The same was seen for DFS (83.3% vs. 77.0%, log rank p=0.38). The results for TN cases were similar (OS : 87.5% vs. 74.1%, log rank p=0.488; DFS 87.5% vs. 60%, log rank p=0.22). CONCLUSION: Although survival estimates trended towards favouring TARGIT-IORT, no significant differences could be observed and the significantly positive result for OS favoring TARGIT-IORT in the whole cohort of 116 patients could not be reproduced in this subset analysis of patients with TN and HER2 positive tumours. This may be contributable to the limited number of patients but may also indicate that effects seen in the whole cohort were mainly driven by ER and/or PR positive and HER2 negative tumours. Most importantly, non-inferiority of TARGIT-IORT as an intraoperative boost could be reproduced in these high-risk patients.

Targeted intraoperative radiotherapy tumour bed boost during breast-conserving surgery after neoadjuvant chemotherapy.

INTRODUCTION: The use of targeted intraoperative radiotherapy (TARGIT-IORT) as a tumour bed boost during breast-conserving surgery (BCS) for breast cancer has been reported since 1998. We present its use in patients undergoing breast conservation following neoadjuvant therapy (NACT). METHOD: In this retrospective study involving 116 patients after NACT we compared outcomes of 61 patients who received a tumour bed boost with IORT during lumpectomy versus 55 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Local recurrence-free survival (LRFS), disease-free survival (DFS), distant disease-free survival (DDFS), breast cancer mortality (BCM), non-breast cancer mortality (NBCM) and overall mortality (OS) were compared. RESULTS: Median follow up was 49 months. The differences in LRFS, DFS and BCM were not statistically significant. The 5­year Kaplan-Meier estimate of OS was significantly better by 15% with IORT: IORT 2 events (96.7%, 95%CI 87.5-99.2), EBRT 9 events (81.7%, 95%CI 67.6-90.1), hazard ratio (HR) 0.19 (0.04-0.87), log rank p = 0.016, mainly due to a reduction of 10.1% in NBCM: IORT 100%, EBRT 89.9% (77.3-95.7), HR (not calculable), log rank p = 0.015. The DDFS was as follows: IORT 3 events (95.1%, 85.5-98.4), EBRT 12 events (69.0%, 49.1-82.4), HR 0.23 (0.06-0.80), log rank p = 0.012. CONCLUSION: IORT during lumpectomy after neoadjuvant chemotherapy as a tumour bed boost appears to give results that are not worse than external beam radiotherapy boost. These data give further support to the inclusion of such patients in the TARGIT-B (boost) randomised trial that is testing whether IORT boost is superior to EBRT boost.