Search

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.

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.

Purpose Using a recently developed matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) method, human breast cancer formalin-fixed paraffin-embedded (FFPE) tissue sections and tissue microarrays (TMA) are evaluated for N-linked glycan distribution in the tumor microenvironment. Experimental design Tissue sections representing multiple human epidermal growth factor receptor 2 (HER2) receptor-positive and triple-negative breast cancers (TNBC) in both TMA and FFPE slide format are processed for high resolution N-glycan MALDI-IMS. An additional FFPE tissue cohort of primary and metastatic breast tumors from the same donors are also evaluated. Results The cumulative N-glycan MALDI-IMS analysis of breast cancer FFPE tissues and TMAs indicate the distribution of specific glycan structural classes to stromal, necrotic, and tumor regions. A series of high-mannose, branched and fucosylated glycans are detected predominantly within tumor regions. Additionally, a series of polylactosamine glycans are detected in advanced HER2+, TNBC, and metastatic breast cancer tissues. Comparison of tumor N-glycan species detected in paired primary and metastatic tissues indicate minimal changes between the two conditions. Conclusions and clinical relevance The prevalence of tumor-associated polylactosamine glycans in primary and metastatic breast cancer tissues indicates new mechanistic insights into the development and progression of breast cancers. The presence of these glycans could be targeted for therapeutic strategies and further evaluation as potential prognostic biomarkers.

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

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.

on 21 early breast cancer patients. All patients gavewritten informed consent approved by the Ethic Committee.After the breast tumor was removed, a tumor sample wasstored by pathologist and sent to Agendia for MammaPrint test.Nine patients had a MammaPrint result which is not use-ful for clinical decision about adjuvant chemotherapy because3 were ductal carcinoma in situ, 4 (22%) had quality of sam-ples not sufficient to perform the MammaPrint assay and 2had both oestrogen- and progesterone-receptors negative andthen patients were candidates for chemotherapy regardlessthe MammaPrint results.In the remaining 12 cases (67%) both clinical risk (definedby clinical-pathological parameters) and MammaPrint riskwere considered for decision-making about adjuvant treat-ment. All cases were discussed in the Breast Disease Manage-ment Team with the presence of medical oncologists, sur-geons and pathologists. Characteristics of the 12 patients areshowed in Table 1.In five (42%) cases (2, 4, 5, 6, 11) clinical risk was dis-cordant with the risk estimated by MammaPrint. In thesecases decision about chemotherapy was based on clinical-pathological factors and disagreed with MammaPrint risk. Infact, in our Institute we recommend chemotherapy in endo-crine-responsive patients with node-positive (2 and 5) or T2tumor or G3 or age 35 years. Conversely, we do not recom-mend usually chemotherapy in endocrine-responsive patientswith age 70 years (4 and 6). Patient 11 had a lobular inva-sive carcinoma and, although she had a T2, we did not rec-ommend chemotherapy because lobular invasive carcinomaappeared to be less responsive to chemotherapy.

Background: Sentinel lymph node (SLN) staging is currently used to avoid complete axillary dissection in breast cancer patients with negative SLNs. Evidence of a similar efficacy, in terms of survival and regional control, of this strategy as compared with axillary resection is based on few clinical trials. In 1998, we started a randomized study comparing the two strategies, and we present here its results. Materials and methods: Patients were randomly assigned to sentinel lymph node biopsy (SLNB) and axillary dissection [axillary lymph node dissection (ALND arm)] or to SLNB plus axillary resection if SLNs contained metastases (SLNB arm). Main end points were overall survival (OS) and axillary recurrence. Results: One hundred and fifteen patients were assigned to the ALND arm and 110 to the SLNB arm. A positive SLN was found in 27 patients in the ALND arm and in 31 in the SLNB arm. Overall accuracy of SLNB was 93.0%. Sensitivity and negative predictive values were 77.1% and 91.1%, respectively. At a median follow-up of 5.5 years, no axillary recurrence was observed in the SLNB arm. OS and event-free survival were not statistically different between the two arms. Conclusions: The SLNB procedure does not appear inferior to conventional ALND for the subset of patients here considered.

Background Breast cancer patients have a cumulative lifetime risk of 2%–15% of developing a contralateral metastatic or ex novo primary cancer. From prognostic and therapeutic viewpoints, it is important to differentiate metastatic from second primary. To distinguish these entities, we investigated whether the pattern of X chromosome inactivation could determine whether the two tumors derived from different progenitor cells. Materials and methods The clonality of bilateral breast cancer was evaluated through the X-inactivation analysis using the human androgen receptor gene (HUMARA) polymorphism and the histopathologic and molecular results were compared. A different or an identical pattern of X inactivation was considered as indicator of a second primary cancer or not informative, respectively. We considered morphological indicators of a new primary cancer the absence of concordance in the histological type or a better histological differentiation. Results Ten patients with bilateral breast cancer were evaluated. Morphological criteria indicated that eight were second primary, a conclusion confirmed by the X-inactivation analysis. Two cases classified as recurrence according to morphological criteria were classified as second tumor by molecular analysis. Conclusion Our results show that the HUMARA clonality assay can improve the histological parameters in differentiating metastatic cancer from second primary cancer.