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The study of circulating cancer-derived components (circulome) is considered the new frontier of liquid biopsy. Despite the recognized role of circulome biomarkers, their comparative molecular profiling is not yet routine. In advanced breast cancer (BC), approximately 40% of hormone-receptor-positive, HER2-negative BC cases harbor druggable PIK3CA mutations suitable for combined alpelisib/fulvestrant treatment. This pilot study investigates PIK3CA mutations in circulating tumor DNA (ctDNA), tumor cells (CTCs), and extracellular vesicles (EVs) with the aim of determining which information on molecular targetable profiling could be recollected in each of them. The in-depth molecular analysis of four BC patients demonstrated, as a proof-of-concept study, that it is possible to retrieve mutational information in the three components. Patient-specific PIK3CA mutations were found in both tissue and ctDNA and in 3/4 cases, as well as in CTCs, in the classical population (large-sized CD45−/EpCAM+/− cells), and/or in the “non-conventional” sub-population (smaller-sized CD44+/EpCAM−/CD45− cells). Consistent mutational profiles of EVs with CTCs suggest that they may have been released by CTCs. This preliminary evidence on the molecular content of the different circulating biomaterials suggests their possible function as a mirror of the intrinsic heterogeneity of BC. Moreover, this study demonstrates, through mutational assessment, the tumor origin of the different CTC sub-populations sustaining the translational value of the circulome for a more comprehensive picture of the disease.

Sentinel lymph node biopsy (SLNB) allows for staging of the axillary node status in early-stage breast cancer (BC) patients and avoiding complete axillary lymph node dissection (ALND) when the sentinel lymph node (SLN) is proven to be free of disease. In a previous randomized trial we compared SLNB followed by ALND (ALND arm) with SLNB followed by ALND only if the SLN presented metastasis (SLNB arm). At a mid-term of ≈ 6 years median follow-up, the two strategies appeared to ensure similar survival and locoregional control. We have revised these previous findings and update the results following a 15-year observation period. Patients were randomly assigned to either the ALND or SLNB arm. The main endpoints were event-free survival (EFS), overall survival (OS), and axillary disease recurrence. EFS and OS were assessed using Kaplan–Meier analysis and the log-rank test. The ALND and SLNB arms included 115 and 110 patients, respectively. At 14.3 years median follow-up, 39 primary BC-related recurrences occurred, 22 (19 %) of which occurred in the ALND arm and 17 (16 %) occurred in the SLNB arm (p = 0.519). No axillary relapse developed in the SLNB arm, while two were observed in the ALND arm. OS (82.0 vs. 78.8 %) and EFS (72.8 vs. 72.9 %) were not statistically different between the ALND and SLNB arms (p = 0.502 and 0.953, respectively). SLNB is a safe and efficacious component of the surgical treatment of early-stage BC patients. In the long-term, SLNB is equivalent to ALND in terms of locoregional nodal disease control and survival in this subset of patients.

Molecular characterization of Circulating Tumor Cells (CTCs) is still challenging, despite attempts to minimize the drawbacks of Whole Genome Amplification (WGA). In this paper, we propose a Next-Generation Sequencing (NGS) optimized protocol based on molecular tagging technology, in order to detect CTCs mutations while skipping the WGA step. MDA-MB-231 and MCF-7 cell lines, as well as leukocytes, were sorted into pools (2&ndash, 5 cells) using a DEPArray&trade, system and were employed to set up the overall NGS procedure. A substantial reduction of reagent volume for the preparation of libraries was performed, in order to fit the limited DNA templates directly derived from cell lysates. Known variants in TP53, KRAS, and PIK3CA genes were detected in almost all the cell line pools (35/37 pools, 94.6%). No additional alterations, other than those which were expected, were found in all tested pools and no mutations were detected in leukocytes. The translational value of the optimized NGS workflow is confirmed by sequencing CTCs pools isolated from eight breast cancer patients and through the successful detection of variants. In conclusion, this study shows that the proposed NGS molecular tagging approach is technically feasible and, compared to traditional NGS approaches, has the advantage of filtering out the artifacts generated during library amplification, allowing for the reliable detection of mutations and, thus, making it highly promising for clinical use.

Background Axillary lymph node dissection (ALND) in early-breast cancer patients with positive sentinel node (SLN+) may not always be necessary. Aims To predict the finding of ≥1 metastatic axillary node in addition to SLN+(s); to discriminate between patients who would or not benefit from ALND. Methods Records of 397 consecutive patients with 1-2 SLN+s receiving ALND were reviewed. Clinico-pathological features were used in univariate and multivariate analyses to develop a logistic regression model predictive of the risk of ≥1 additional axillary node involved. The discrimination power of the model was quantified by the area under the receiver operating characteristic curve (AUC) and validated using an independent set of 83 patients. Results In univariate analyses, the risk of ≥1 additional node involved was correlated with tumor size, grade, HER-2 and Ki-67 over-expression, number of SLN+s. All factors, but Ki-67, retained in multivariate regressions were used to generate a predictive model with good discriminating power on both the training and the validation sets (AUC 0.73 and 0.75, respectively). Three patient groups were defined based on their risk to present additional axillary burden. Conclusions The model identifies SLN+-patients at low risk (≤15%) who could reasonably be spared ALND and those at high risk (>75%) who should receive ALND. For patients at intermediate risk, ALND appropriateness could be individually evaluated based on other clinico-pathological parameters.

Background Feasibility and accuracy of sentinel node biopsy (SLNB) after the delivery of neo-adjuvant chemotherapy (NAC) is controversial. We here report our experience in NAC-treated patients with locally advanced breast cancer and clinically positive axillary nodes, and compare it with the results from our previous randomized trial assessing SLNB in early-stage breast cancer patients. Patients and methods Sixty-four consecutive patients with large infiltrating tumor and clinically positive axillary nodes received NAC and subsequent lymphatic mapping, SLNB and complete axillary lymph node dissection (ALND). The status of the sentinel lymph node (SLN) was compared to that of the axilla. Results At least one SLN was identified in 60 of the 64 patients (93.8%). Among those 60 patients, 37 (61.7%) had one or more positive SLN(s) and 23 (38.3%) did not. Two of the patients with negative SLN(s) presented metastases in other non-sentinel nodes. SLNB thus had a false-negative rate, a negative predictive value and an overall accuracy of 5.1%, 91.3% and 96.7%, respectively. All these values were similar to those we reported for SLNB in the settings of early-stage breast cancer. Conclusion SLNB after NAC is safe and feasible in patients with locally advanced breast cancer and clinically positive nodes, and accurately predicts the status of the axilla.

Several studies have shown that the majority of in-breast recurrences following lumpectomy are at or near the original tumor site while ipsilateral breast recurrences further afield occur rarely. This suggests that the radiation dose could be delivered exclusively to the tumor bed, allowing larger fractions to be used without increasing toxicity and shortening the total treatment time. We investigated the use of the MammoSite irradiation system with a view to analyzing complications, cosmesis and patient comfort. Between 2004 and 2007 intracavity brachytherapy was given to 30 patients using the MammoSite device. The reference isodose was prescribed to the lumpectomy cavity with a 1 cm margin. Geometric parameters and anatomic position of the applicator after implantation were checked via CT, x-ray and ultrasound. Analysis was done for patient quality of life, cosmesis, early and late complications. Forty-nine patients received a proposal for MammoSite brachytherapy. Nine declined, 40 enrolled while 10 were excluded for various reasons (Table 5). A total of 30 patients were actually treated to 34 Gy (2 × 3.4 Gy) in 5 days. We observed 3 cases (10%) of infection within 3 months of implantation. Symptomatic seroma was seen in five patients (16.6%) at 6 months, in three (10%) at 12 months, and in just one patient (3.3%) at 18 months. Good to excellent cosmetic results were achieved in 75% by patient and physician ratings. Accelerated partial breast irradiation using the MammoSite catheter produces favorable short-term outcomes, limited toxic effects on skin, and optimal cosmetic results. Patient tolerance for the treatment is very high. Critical issues may regard the importance of good cavity conformance and adequate balloon-skin distance in avoiding possible dose excesses to the skin. For a selected patient group, this could be a valid alternative to conventional whole breast irradiation. Table 5. Causes of Exclusion from the Protocol Causes No. pts EIC 1 Tumor size 2 Lobular carcinoma 3 Rupture 1 N+ 3

Background and Objectives Recent studies have demonstrated that the sentinel lymph node (sN) can be considered a reliable predictor of axillary lymph node status in breast cancer patients. However, some important issues, such as optimization of the technique for the intraoperative identification of the sN, and the clinical implications of sN metastasis as regards the surgical management of the axilla still require further elucidation. The objectives of this study was to assess (1) the feasibility of sN identification with a combined approach (vital blue dye lymphatic mapping and radioguided surgery, RGS) and the specific contribution of either techniques to the detection of the sN, and (2) the correlation between the size of sN metastasis (micrometastasis ≤ 2 mm; macrometastasis > 2), primary tumour size, and the status of nonsentinel nodes (nsN) in the axilla. Methods Between October of 1997 and December of 1999, 212 patients with breast cancer (average age: 61 years; range, 40–79 years) underwent sN biopsy before performing standard axillary dissection. In a subset of 153 patients, both vital blue dye (Patent Blue-V) lymphatic mapping and RGS were used to identify the sN, and the relative contribution of each of the two techniques was assessed. Results Overall, the sN was identified in 206 of 212 patients (97.1%); at histologic examination of all dissected nodes, 77 of 206 patients had positive nodes (37.3%). The false-negative rate was 6.5% (5/77), the negative predictive value was 96.3% (129/134), and accuracy was 97.6% (201/206). Among 72 patients with positive sN, micrometastases were detected in 21 cases and macrometastases in 51. When micrometastases only were observed, the sN was the exclusive site of nodal metastasis in 17 of 21 cases (80.9%); in the remaining 4 cases (19.1%), nsN metastases were detected in 3 of 14 pT1c patients (21.5%), and 1 of 5 pT2 patients (20%). Macrometastases were detected in patients with tumors classified as pT1b or larger: the sN was the exclusive site of metastasis in 3 of 4 pT1b patients (75%), in 14 of 29 pT1c patients (48.2%), and in 3 of 18 pT2 patients (16.6%). The specific contribution of the two different techniques used in the identification of the sN was evaluated; the detection rate was 73.8% (113 of 153) with Patent Blue-V alone, 94.1% (144 of 153) with RGS alone, and 98.7% (151 of 153) with Patent Blue-V combined with RGS (P

Defective DNA repair has been suggested as a possible predisposing factor for breast cancer. We have investigated the repair of the frequent endogenous lesions abasic sites in sporadic early onset breast cancer patients and matched control individuals. No significant difference was observed between the abasic site repair capacities of peripheral blood lymphocytes from cases and controls. Repair of abasic sites was also studied in tumor and surrounding normal tissues of the patients. The 2 tissues showed marked differences in histology and protein composition with a fibro-collagenous component varying from sample to sample but invariably higher in normal tissues as compared with the adjacent tumor. These differences involved the need to calculate the repair activities of tissues on the basis of cellular DNA content for comparison purposes. After doing so, tumor and normal tissues exhibited similar abasic site repair capacities, whereas lymphocytes showed a repair capacity significantly lower than tissues. We conclude that early onset sporadic breast cancer patients show no evident defect in repair of abasic sites at the level of both lymphocytes and tumor.