BackgroundTo report results in terms of feasibility and early toxicity of hypofractionated simultaneous integrated boost (SIB) approach with Volumetric Modulated Arc Therapy (VMAT) as adjuvant treatment after breast-conserving surgery.MethodsBetween September 2010 and May 2011, 50 consecutive patients presenting early-stage breast cancer were submitted to adjuvant radiotherapy with SIB-VMAT approach using RapidArc in our Institution (Istituto Clinico Humanitas ICH). Three out of 50 patients were irradiated bilaterally (53 tumours in 50 patients). All patients were enrolled in a phase I-II trial approved by the ICH ethical committee. All 50 patients enrolled in the study underwent VMAT-SIB technique to irradiate the whole breast with concomitant boost irradiation of the tumor bed. Doses to whole breast and surgical bed were 40.5 Gy and 48 Gy respectively, delivered in 15 fractions over 3 weeks. Skin toxicities were recorded during and after treatment according to RTOG acute radiation morbidity scoring criteria with a median follow-up of 12 months (range 8–16). Cosmetic outcomes were assessed as excellent/good or fair/poor.ResultsThe median age of the population was 68 years (range 36–88). According to AJCC staging system, 38 breast lesions were classified as pT1, and 15 as pT2; 49 cases were assessed as N0 and 4 as N1. The maximum acute skin toxicity by the end of treatment was Grade 0 in 20/50 patients, Grade 1 in 32/50, Grade 2 in 0 and Grade 3 in 1/50 (one of the 3 cases of bilateral breast irradiation). No Grade 4 toxicities were observed. All Grade 1 toxicities had resolved within 3 weeks. No significant differences in cosmetic scores on baseline assessment vs. 3 months and 6 months after the treatment were observed: all patients were scored as excellent/good (50/50) compared with baseline; no fair/poor judgment was recorded. No other toxicities or local failures were recorded during follow-up.ConclusionsThe 3-week course of postoperative radiation using VMAT with SIB showed to be feasible and was associated with acceptable acute skin toxicity profile. Long-term follow-up data are needed to assess late toxicity and clinical outcomes.

Mucinous carcinoma (MC) is a rare breast cancer characterized by the presence of large extracellular mucin amount. Two main subtypes can be distinguished: pure (PMC) and mixed (MMC). We conducted a retrospective MC analysis in our prospective maintained database, calculating disease-free survival (DFS) and 5-year overall survival (OS). We found a global 92.1% OS (higher in MMC group and statistically significative) and a DFS of 95.3% (higher in MMC group but not statistically significative).

Depending on location, size and histological features, SFTP may produce a large spectrum of findings. Typical CT features of small SFTP were well-defined margins and smooth contours, homogeneous attenuation and right or obtuse angles with the pleura. Larger lesions were characterised by well-defined margins and lobulated contours, geographic pattern in enhanced CT scans, acute angles or smooth tapering margins with the pleura.

The prognosis of patients with hepatic metastasis from breast cancer treated with systemic or regional chemotherapy is disappointing. When technically feasible, liver resection offers the best results. Eighteen patients out of 22 submitted to laparotomy underwent radical liver resection. Median follow-up from liver resection was 36 months. The median time interval between breast cancer diagnosis and disease recurrence was 35 months. Median disease-free survival and overall survival from liver resection were 66 and 74 months, respectively. Median survival time from breast cancer surgery was 88.5 months. Surgical treatment of liver metastases should be carried out on young and older patients alike when site of metastases is the liver alone. Neoadjuvant treatment and preoperative diagnostic laparoscopy should be planned in future experience.

Introduction: Sentinel lymph node (SLN) staging is currently used to avoid complete axillary lymph node dissection (ALND) in breast cancer (BC) patients. The SLN is the only site of axillary metastasis (MTS) in ≤60% of cases. Recently, a randomized controlled trial (Z0011) comparing SLN biopsy (SLNB) alone with SLNB followed by ALND in patients with 1-2 SLNs+ demonstrated no significant statistical difference in relapse and overall survival rates among the two different groups. However, this study had some limitations: small tumor size (≤2cm in 70% of cases), frequent presence of only microMTS in SLN (40%), prevalent use of “whole breast” adjuvant radiotherapy (>90%). Given these considerations, the SINODAR-ONE study started in April 2015.Objectives: The aims are to assess whether ALND omission in BC patients with 1-2 SLNs+ is associated with worse survival and/or increased rate of regional/distant relapse. Thus evaluating whether SLNB is or is not inferior to ALND. Primary endpoint is overall survival (OS). Secondary endpoints are disease-free survival (DFS) referring to distant MTS and loco-regional recurrence. Methods: Patients receive either mastectomy or conservative surgery plus radiotherapy. They all undergo SLNB and are randomly divided into two arms of treatment: standard (SLNB plus ALND) or experimental treatment (only SLNB). According to multidisciplinary evaluation, patients may undergo additional adjuvant radiotherapy, chemo- and/or hormonal therapy , or no further therapy. Eligibility criteria: age 40-75 years; primary invasive T1-T2 tumor; axillary nodes clinically N0; no more than 2 macro-metastatic SLNs; no distant MTS; no neo-adjuvant therapy; no previous invasive BC; signed informed consent. Exclusion criteria: in situ, inflammatory, contralateral BC; micro-metastic SLNs; pregnancy or breast feeding; comorbidity impeding adjuvant therapy. All analyses are performed both on all patients according to the Intention-To-Treat principle and excluding those patients who did not receive the axillary treatment randomly assigned. Statistical analysis: OS and DFS are calculated using the Kaplan-Meier Product Limit Estimator and differences between arms are assessed with the log-rank test. Results: The enrollment of patients ended in April 2020 with a total of 889 cases (443: standard arm; 446: experimental arm). In June 2020, we conducted an ad interim analysis on 889 patients. We found the two groups homogeneous for epidemiologic characteristics (age and menopausal status), tumor characteristics (tumor size, pTNM, immunohistochemistry, histology, grading, vascular and lymphatic invasion), adjuvant therapies and surgery on T. In particular we have performed a 23,1% of mastectomies in the standard arm and 20,1% in the experimental arm. We found a median of 2 sentinel lymph nodes removed in both arms and 1 non-sentinel positive lymph node in the experimental arm, and only 3 micro-metastases (1 in the standard arm and 2 in the experimental arm). Conclusion: In sum, with a median follow-up of 30 months, there have been no axillary recurrence in both arms. In the standard arm we found 8 total events (2 deaths and 6 distant relapses) and in in the experimental arm 6 events (1 death and 5 distant relapses), with a projected 5-years cumulative incidence of 6,5% in standard arm and 4,85% in the experimental arm. Citation Format: Corrado Tinterri, Emilia Marrazzo, Chiara Anghelone, Erika Barbieri, Andrea Sagona, Alberto Bottini, Arianna Rubino, Damiano Gentile, Wolfgang Gatzemeier, Valentina Errico, Alberto Testori, Giuseppe Canavese. Preservation of axillary lymph nodes compared to complete dissection in T1-T2 breast cancer patients presenting 1-2 metastatic sentinel lymph nodes : A multicenter randomized clinical trial. Sinodar One. [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 PD4-01.