Targeting PIK3CA Actionable Mutations in the Circulome: A Proof of Concept in Metastatic Breast Cancer.

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.

Optimization of a WGA-Free Molecular Tagging-Based NGS Protocol for CTCs Mutational Profiling.

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 (2-5 cells) using a DEPArray™ 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.

Sentinel Lymph Node Biopsy Versus Axillary Dissection in Node-Negative Early-Stage Breast Cancer: 15-Year Follow-Up Update of a Randomized Clinical Trial.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Correlation between outcome and extent of residual disease in the sentinel node after neoadjuvant chemotherapy in clinically fine-needle proven node-positive breast cancer patients.

BACKGROUND: Whether the extent of residual disease in the sentinel lymph node (SLN) after neoadjuvant chemotherapy (NAC) influences the prognosis in clinically node-positive breast cancer (BC) patients remains to be ascertained. METHODS: One hundred and thirty-four consecutive cN+/BC-patients received NAC followed by SLN biopsy and axillary lymph node dissection. Cumulative incidence of overall (OS) and disease-free (DFS) survival, BC-related recurrences and death from BC were assessed using the Kaplan-Meier method both in the whole patient population and according to the SLN status. The log rank test was used for comparisons between groups. RESULTS: The SLN was identified in 123/134 (91.8%) patients and was positive in 98/123 (79.7%) patients. Sixty-five of them (66.3%) had other axillary nodes involved. SLN sensitivity and false-negative rate were 88.0% and 2.0%, Median follow-up was 10.2 years. Ten-year cumulative incidence of axillary, breast and distant recurrences, and death from BC were 6.5%, 11.9%, 33.4% and 31.3%, respectively. Ten-year OS and DFS were 67.3% and 55.9%. When stratified by SLN status, 10-year cumulative incidence of BC-related and loco-regional events, and death from BC were similar between disease-free SLN and micrometastatic SLN subgroups (28.9% vs 30.2%, p = 0.954; 21.6% vs 13.4%, p = 0.840; 12.9 vs 24.5%, p=0.494). Likewise, 10-year OS and DFS were comparable (80.0% vs 75.5%, p=0.975 and 68.0% vs 69.8, p=0.836). Both OS and DFS were lower in patients presenting a macrometastatic SLN (60.2% and 47.5%). CONCLUSION: Outcome of patients with micrometastatic SLN was similar to that of patients with disease-free SLN, which was more favorable as compared to that of patients with macrometastatic SLN.

Radiation-Related Deregulation of TUBB3 and BRCA1/2 and Risk of Secondary Lung Cancer in Women With Breast Cancer.

INTRODUCTION: Breast cancer survivors are at increased risk of developing unrelated primary cancers, particularly lung cancer. Evidence indicates that sex hormones as well as a deregulation of DNA-repair pathways may contribute to lung cancer onset. We investigated whether the hormone status and expression of markers involved in DNA repair (BRCA1/2, ERCC1, and P53R2), synthesis (TS and RRM1), and cell division (TUBB3) might be linked to lung cancer risk. PATIENTS AND METHODS: Thirty-seven breast cancer survivors with unrelated lung cancer and 84 control subjects comprising women with breast cancer (42/84) or lung cancer (42/84) were enrolled. Immunohistochemistry on tumor tissue was performed. Geometric mean ratio was used to assess the association of marker levels with patient groups. RESULTS: Estrogen receptor was expressed in approximately 90% of the breast cancer group but was negative in the majority of the lung cancer group, a result similar to the lung cancer control group. Likewise, ER isoform ß was weakly expressed in the lung cancer group. Protein analysis of breast cancer versus control had a significantly lower expression of BRCA1, P53R2, and TUBB3. Likewise, a BRCA1 reduction was observed in the lung cancer group concomitant with a BRCA2 increase. Furthermore, BRCA2 and TUBB3 increased in ipsilateral lung cancer in women who had previously received radiotherapy for breast cancer. CONCLUSION: The decrease of DNA-repair proteins in breast cancer could make these women more susceptible to therapy-related cancer. The increase of BRCA2 and TUBB3 in lung cancer from patients who previously received radiotherapy for breast cancer might reflect a tissue response to exposure to ionizing radiation.

Accelerated partial breast irradiation via the mammosite catheter: preliminary reports of a single-institution experience.

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 a field 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 x 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.

Increases in Tumor N-Glycan Polylactosamines Associated with Advanced HER2-Positive and Triple-Negative Breast Cancer Tissues.

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.

Flat epithelial atypia: conservative management of patients without residual microcalcifications post-vacuum-assisted breast biopsy.

OBJECTIVE: To determine the malignancy rate (defined in this study as stability or absence of malignancy developed on close imaging follow-up post-biopsy) of conservative management in patients with a vacuum-assisted breast biopsy (VAB) diagnosis of flat epithelial atypia (FEA), performed on single group of microcalcifications, completely removed during procedure. METHODS: This is a retrospective, monocentric, observational study, approved by IRB. Inclusion criteria were: VAB performed on a single group of microcalcifications; the absence of residual calcifications post-VAB; diagnosis of isolated FEA as the most advanced proliferative lesion; radiological follow-up at least of 12 months. The personal history of breast cancer or other high-risk lesions was an exclusion criteria. The patients enrolled were conservatively managed, without surgical excision, through close follow-up: the first two mammographies performed with an interval of 6 months after biopsy, followed by annual mammographic and clinical checks. RESULTS: 48 consecutive patients were enrolled in the study, all females, with age range of 39-76 years (mean 53,3 years) and radiological follow-up range of 13-75 months (mean 41.5 months). All the lesions were classified as BI-RADS 4b. The diameter range of the group of calcifications was 3-10 mm (mean 5, 6 mm). In each patient, 7 to 15 samples (mean 11) were obtained. Among all the patients, there was only one case (2%) of new microcalcifications, developed in the same breast, 26 months after and 8 mm from the site of previous VAB, and interpreted as ADH at surgical excision. All the checks of the other patients were negative. CONCLUSION: Even with a limited follow-up, we found a malignancy rate lower than 2%, through a defined population. Further studies with bigger number of patients and extended follow-up are needed to reinforce this hypothesis. Advances in knowledge: Surgical excision may not be necessary in patients with VAB diagnosis of isolated FEA, without residual microcalcifications post-procedure and considered concordant with the mammographic presentation, considering the low rate of malignancy at subsequent follow-ups.

Progesterone receptor status and clinical outcome in breast cancer patients with estrogen receptor-positive locoregional recurrence.

AIMS AND BACKGROUND: The aim of this retrospective multicenter study was to evaluate the impact of progesterone receptor (PgR) loss on locoregional recurrence in patients with estrogen receptor (ER)-positive primary breast cancer and ER-positive locoregional recurrence. PATIENTS AND METHODS: Eight Italian oncology centers collected data from consecutive patients with ER-positive breast cancer and a subsequent ER-positive locoregional recurrence. RESULTS: Data were available for 265 patients diagnosed with breast cancer between 1990 and 2009. Median metastasis-free survival was 111 months in patients with PgR-positive primary tumors and locoregional recurrence (PgRpos), 38 months in patients with PgR-negative primary tumors and locoregional recurrence (PgRneg), and 63 months in patients with PgR-positive primary tumors and PgR-negative locoregional recurrence (PgRloss). In multivariate analysis, PgR status was independently associated with metastasis-free survival, with a hazard ratio of 2.84 (95% CI 1.34-6.00) for PgRneg compared with PgRpos, and 2.93 (95% CI: 1.51-5.70) for PgRloss compared with PgRpos. CONCLUSIONS: PgR absence was found to be a negative prognostic factor in breast cancer patients with ER-positive locoregional recurrence. Thus, PgR status could be a biological marker in ER-positive recurrent breast cancer.

Predictive factors of non-sentinel lymph node involvement in patients with invasive breast cancer and sentinel node micrometastases.

Patient-related, tumor-related, and sentinel node (SN)-related factors have been identified with the aim of predicting non-SN status in patients with SN micrometastases. According to our previous experience, primary tumor size (p=0.005) and the presence of lymphovascular invasion (LVI) (p=0.000) significantly predicted non-SN status in patients with SN micrometastasis; moreover, non-SN metastases were never detected in patients with pT1a-1b, G1, and no LVI. A prospective assessment was undertaken in a validation set of 126 patients to confirm these findings. Univariate analysis indicated that primary tumor size (p=0.05), Scarff-Bloom-Richardson (SBR) grade (p=0.008), LVI (p=0.001), and the number of mitoses/mm(2) (p=0.01) were significant predictors of non-SN status. By logistic regression analysis, tumor size (p=0.03), LVI (p=0.001), grade (p=0.003) and the number of mitoses/mm(2) (p=0.01) were the only variables remaining in the model. Three subsets of patients were identified: i) 18.3% of patients (pT1, G1, and no LVI) had tumor-negative non-SN (no risk group); ii) 37.3% of patients (number of mitoses/mm(2) <10, SBR grade II-III) had a rate of tumor-positive non-SN <15% (intermediate risk); iii) 44.4% of patients had a mean rate of non-SN involvement of 46% (high risk). By these parameters, more than 50% of patients could be selectively spared unnecessary axillary lymph node dissection without staging or therapeutic benefit, especially in patients with well-differentiated pT1 tumors without LVI.

Analysis and clinical relevance of human leukocyte antigen class I, heavy chain, and beta2-microglobulin downregulation in breast cancer.

Investigation is lacking regarding the clinical impact of human leukocyte antigen (HLA) class I downregulation in breast cancer and results are inconsistent. In this study, we investigated the expression of HLA class I, the heavy chain, and beta2-microglobulin (beta2-m) by immunohistochemistry in 67 breast carcinomas (BC) and correlated results with clinical-pathologic parameters and patient outcomes. Seventy-six percent of BC were downregulated for HLA class I, whereas downregulation of heavy chain and beta2-m was observed in 57 and 46% of BC, respectively. A significant association existed between the absence of tumor necrosis and downregulation of class I and beta2-m and between the absence of lymphovascular invasion and patient's age and downregulated class I and heavy chain, respectively. Among the lymph node-positive BC patients, a significantly improved overall survival was observed in those showing beta2-m downregulation compared with patients with normal beta2-m. This result may correlate with the role of beta2-m in regulating cancer cell growth.