Overcoming Limitations in Decarboxylative Arylation via Ag-Ni Electrocatalysis.

A useful protocol for achieving decarboxylative cross-coupling (DCC) of redox-active esters (RAE, isolated or generated in situ) and halo(hetero)arenes is reported. This pragmatically focused study employs a unique Ag-Ni electrocatalytic platform to overcome numerous limitations that have plagued this strategically powerful transformation. In its optimized form, coupling partners can be combined in a surprisingly simple way: open to the air, using technical-grade solvents, an inexpensive ligand and Ni source, and substoichiometric AgNO3, proceeding at room temperature with a simple commercial potentiostat. Most importantly, all of the results are placed into context by benchmarking with state-of-the-art methods. Applications are presented that simplify synthesis and rapidly enable access to challenging chemical space. Finally, adaptation to multiple scale regimes, ranging from parallel milligram-based synthesis to decagram recirculating flow is presented.

Health-Related Quality of Life After Nipple-Sparing Mastectomy: Results From the INSPIRE Registry.

INTRODUCTION: Nipple-sparing mastectomy (NSM) with immediate breast reconstruction (IBR) is increasingly used for both breast cancer (TNSM) and risk reduction (RRNSM). The aim of the study is to report the results of the INSPIRE registry assessing health-related quality of life (HRQoL) comparing baseline and 1-year follow-up, regarding surgical indications and chemotherapy (CT) received. METHODS: INSPIRE is a prospective database including women undergoing NSM and IBR from 18 countries. HRQoL was measured using EORTC QLQC30 and QLQ-BR23 before surgery and after 1 year. RESULTS: A total of 677 women were included, of whom 537 (79.3%) underwent TNSM and 140 (21.6%) RRNSM: in total, 806 NSM (556 TNSM and 250 RRNSM). Nipple involvement was present in 7.73% of TNSM and incidental carcinoma in 1.2% of the RRNSM group. Out of the overall 537 patients with systemic treatment, 177 (32.96%) received neoadjuvant chemotherapy (NCT) and 118 (21.92%) adjuvant chemotherapy (CT). A total of 227 patients (28.16%) developed at least one complication postoperatively, 164 (29.5%) in the TNSM group and 63 (25.2%) in the RRNSM group. The TNSM group improved in global health status and emotional functioning after 1 year. No differences were found when comparing HRQoL at 1 year between patients who received NCT and those who received adjuvant CT. The RRNSM group showed improvement in HRQoL, with better emotional functioning and fatigue after 1 year. CONCLUSIONS: This registry reports HRQoL findings after NSM. The impact of CT on worse HRQoL is independent from its timing. Patients with RRNSM showed an improved HRQoL at 1-year follow-up. Discussion of HRQoL outcomes with patients will facilitate the informed decision-making when considering NSM.

Leveraging the increased rates of pathologic complete response after neoadjuvant treatment in breast cancer to de-escalate surgical treatments.

INTRODUCTION: Breast conservative surgery (BCS) and sentinel lymph node biopsy (SLNB) after neoadjuvant treatment (NAT) is safe and effective for selected patients. This aim of this study is to evaluate the impact of anatomic site of response on outcomes and to assess the real population who may benefit from nonsurgical approaches after NAT. MATERIAL AND METHODS: From a prospectively maintained database, patients with T1-4 N0-2 breast cancer undergoing NAT were identified. Clinicopathological and survival rates were compared in relation to response and anatomic site of response. RESULTS: Six hundred and forty-six patients were included in the study. Pathologic complete response (pCR) was an independent factor for BCS and SLN. HER2 positive and TN tumors with cN0 achieving a breast pCR remain ypN0 (p = .002). Residual axillary disease was associated with breast residual tumor (p = .05) and subtype (p = .001). With a median follow up of 35.25 months, patients with any pCR had improved survival when compared with partial response, but not significant differences between pCR, axillary pCR, or breast pCR. CONCLUSION: Achieving a pCR increases BCS and SLN. In selected subgroups, sparing any axillary surgery after NAT maybe feasible. In cN+ patients, any pCR was associated with survival, but not the anatomic site of response.

Acyclic Stereocontrol in the Additions of Nucleophilic Alkenes to α-Chiral N-Sulfonyl Imines.

Diastereoselective Lewis acid-mediated additions of nucleophilic alkenes to N-sulfonyl imines are reported. The canonical polar Felkin-Anh model describing additions to carbonyls does not adequately describe analogous additions to N-sulfonyl imines. Herein, we describe the development of conditions to produce both syn and anti products with high diastereoselectivity and good yields. A stereoelectronic model consistent with experimental outcomes is also proposed.

Intraoperative Ultrasound-Guided Excision of Axillary Clip in Patients with Node-Positive Breast Cancer Treated with Neoadjuvant Therapy (ILINA Trial) : A New Tool to Guide the Excision of the Clipped Node After Neoadjuvant Treatment.

BACKGROUND: The accuracy of sentinel lymph node biopsy (SLNB) after neoadjuvant therapy (NAT) has been improved with the placement of a clip in the positive node prior to treatment. Several methods have been described for clipped node excision during SLNB after NAT. We assessed the feasibility of intraoperative ultrasound (IOUS)-guided excision of the clipped node during SLNB and investigated whether the accuracy of SLNB is improved. METHODS: After approval by the Institutional Ethics Committee, all breast cancer patients undergoing NAT had an US-visible clip placed in the positive node. The ILINA trial consisted of IOUS-guided excision of the clipped node along with SLNB and axillary lymph node dissection (ALND). RESULTS: Forty-six patients had a clip placed in the positive node. In two (4.3%) cases, the clip could not be seen prior to surgery and the patient underwent ALND; however, the clipped node was successfully removed by IOUS-guided excision in 44 patients. Thirty-five patients (79.5%) underwent SLNB along with IOUS-guided excision of the clipped node and ALND, and were subsequently included in the ILINA trial. Nine patients were not included (five patients with SLNB only and four patients with ALND without SLNB). SLNB matched the clipped node in 27 (77%) patients. The false negative rate for the ILINA protocol was 4.1% (95% confidence interval 0.1-21.1%). CONCLUSIONS: IOUS-guided excision of the axillary clipped node after NAT was feasible, safe, and successful in 100% of cases. The ILINA trial is accurate in predicting axillary nodal status after NAT.

Acute pulmonary involvement by paracoccidiodomycosis disease immediately after kidney transplantation: Case report and literature review.

Paracoccidioides brasiliensis is the cause of paracoccidioidomycosis, one of the most important systemic mycoses in Latin America. Human disease has been observed in a limited geographic and ecological niche, and it is attributed to exposure to the fungus in soil. Most primary infections are subclinical, as the infection is contained by the host mainly through cell-mediated immune response. However, as the fungus has the ability to survive in a dormant state for long periods, an impairment of the immune response may lead to reactivation and clinical disease. Surprisingly, paracoccidioidomycosis has rarely been reported in transplanted patients. The aim of this communication is to report a case occurring in a kidney recipient in an acute clinical form immediately after transplantation, and to review the available information on previously reported cases.

Intraoperative Ultrasound-Guided Lumpectomy Versus Mammographic Wire Localization for Breast Cancer Patients After Neoadjuvant Treatment.

BACKGROUND: Intraoperative ultrasound (IOUS)-guided lumpectomy in early breast cancer has shown advantages over other techniques. However, the use of IOUS has been less explored after neoadjuvant treatment (NAT). This study aimed to compare IOUS- and wire localization (WL)-guided surgery in breast cancer patients after NAT. METHODS: The study enrolled patients treated with NAT who underwent breast-conserving surgery (BCS) between July 2008 and December 2012. For the patients with a hydrogel marker or residual tumor visible on ultrasound, an IOUS-guided surgery was performed (IOUS group). The patients with a standard marker or hydrogel marker not visible on ultrasound underwent a WL-guided surgery (WL group). RESULTS: The study investigated 214 patients: 145 (67.8 %) in the IOUS group and 69 (32.2 %) in the WL group. The patient and tumor characteristics were comparable between the two groups. For the patients who had a pathologic complete response (pCR) or microscopic disease, the volume excised was lower in the IOUS group (p = 0.03). The rate of reexcision for positive or close margins was similar in the two groups (p = 0.80). After a median follow-up period of 43 months, the local recurrence rates did not differ significantly between the two groups. CONCLUSIONS: Compared with WL surgery, IOUS seems to lower the volume of resection in patients with pCR or minimal microscopic disease after NAT without compromising margins and local recurrences. BCS can easily be achieved with IOUS for patients with a good response after NAT.

Different Prognostic Implications of Residual Disease After Neoadjuvant Treatment: Impact of Ki 67 and Site of Response.

BACKGROUND: Pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) can be used as an independent prognostic factor in neoadjuvant trials. The objective of this study was to determine the impact of Ki 67 expression and site of response on overall survival (OS) and disease-free survival (DFS) across different molecular subtypes of breast cancer following NAC. METHODS: Records from 357 patients who received NAC from 2004 to 2011 were reviewed. Univariate and multivariate analyses were performed to analyze clinical and pathological factors that influence pCR and DFS. RESULTS: Mean follow-up time was 45 months (range 12-112). pCR was achieved in 82 patients (23 %). According to molecular subtypes, rates of pCR were significantly higher for patients with HER2-positive and triple-negative tumors (69.4 and 32.7 %, respectively; p < 0.001) compared with other molecular subtypes. pCR was a predictive factor of longer OS and DFS. The hazard ratio for DFS in patients with positive lymph nodes (ypN1) after NAC was 2.48 (95 % confidence interval 1.47-4.19). Multivariate analysis showed that molecular subtype, changes in Ki 67 expression, and axillary lymph node response were significantly predictors of OS and DFS. CONCLUSIONS: pCR in the axilla and posttreatment changes in Ki 67 after NAC are associated with improved survival. Depending on axillary staging before NAC, detection of minimal residual disease-defined as the presence of isolated tumor cells in the SLN after NAC-may confer different prognosis. Further studies are needed to tailor treatments for patients with residual disease after NAC.

Nomogram including the total tumoral load in the sentinel nodes assessed by one-step nucleic acid amplification as a new factor for predicting nonsentinel lymph node metastasis in breast cancer patients.

Several models have been developed to predict non-sentinel nodes (NSLN) metastasis in patients with a positive sentinel node (SLN) that incorporates a standard pathology examination of the SLN. It has been reported that total tumoral load (TTL) in the SLNs assessed by one-step nucleic acid amplification (OSNA) is a predictive factor for additional NSLN metastasis in the axillary lymph node dissection (ALND). The objective was to develop a nomogram that predicts patient´s risk of additional NSLN metastasis incorporating TTL in the SLNs assessed by OSNA. Six hundred and ninety-seven consecutive patients with positive SLN evaluation by OSNA and a completion ALND were recruited. Pathologic features of the primary tumor and SLN metastases, including TTL were collected. Multivariate logistic regression identified factors predictive of non-SLN metastasis. A nomogram was developed with these variables and validated in an external cohort. On multivariate logistic regression analysis, tumor size, number of affected SLN, Her2 overexpression, lymphovascular invasion, and TTL were each associated with the likelihood of additional NSLN metastasis (p < 0.05). The overall predictive accuracy of the nomogram, as measured by the AUC was 0.7552 (95 %CI 0.7159-0.7945). When applied to the external cohort the nomogram was accurate with an AUC = 0.678 (95 %CI 0.621-0.736). This novel nomogram that incorporates TTL assessed by OSNA performs well and may help clinicians to make decisions about ALND for individual patients. Moreover, the standardization of pathologic assessment by OSNA may help to achieve interinstitutional reproducibility among nomograms.

Patritumab deruxtecan in HER2-negative breast cancer: part B results of the window-of-opportunity SOLTI-1805 TOT-HER3 trial and biological determinants of early response.

Patritumab deruxtecan (HER3-DXd) exhibits promising efficacy in breast cancer, with its activity not directly correlated to baseline ERBB3/HER3 levels. This research investigates the genetic factors affecting HER3-DXd's response in women with early-stage hormone receptor-positive and HER2-negative (HR+/HER2-) breast cancer. In the SOLTI-1805 TOT-HER3 trial, a single HER3-DXd dose was administered to 98 patients across two parts: 78 patients received 6.4 mg/kg (Part A), and 44 received a lower 5.6 mg/kg dose (Part B). The CelTIL score, measuring tumor cellularity and infiltrating lymphocytes from baseline to day 21, was used to assess drug activity. Part A demonstrated increased CelTIL score after one dose of HER3-DXd. Here we report CelTIL score and safety for Part B. In addition, the exploratory analyses of part A involve a comprehensive study of gene expression, somatic mutations, copy-number segments, and DNA-based subtypes, while Part B focuses on validating gene expression. RNA analyses show significant correlations between CelTIL responses, high proliferation genes (e.g., CCNE1, MKI67), and low expression of luminal genes (e.g., NAT1, SLC39A6). DNA findings indicate that CelTIL response is significantly associated with TP53 mutations, proliferation, non-luminal signatures, and a distinct DNA-based subtype (DNADX cluster-3). Critically, low HER2DX ERBB2 mRNA, correlates with increased HER3-DXd activity, which is validated through in vivo patient-derived xenograft  models. This study proposes chemosensitivity determinants, DNA-based subtype classification, and low ERBB2 expression as potential markers for HER3-DXd activity in HER2-negative breast cancer.

Intraoperative molecular analysis of total tumor load in sentinel lymph node: a new predictor of axillary status in early breast cancer patients.

OBJECTIVE: To assess the intraoperative positive sentinel lymph node (SLN) total tumor load (TTL, defined as the amount of CK19 mRNA copies [copies/µL] in all positive SLNs) obtained by one-step nucleic acid amplification (OSNA) and to determine whether it is predictive of non-SLNs involvement. SUMMARY/BACKGROUND/DATA: The OSNA assay (Sysmex Corporation, Kobe, Japan) is a new diagnostic technique that uses molecular biological techniques to analyze SLN that has been validated as an accurate method for detection of positive SLN. Although the American College of Surgeons Oncology Group Z0011 trial has defined a select cohort of patients in whom a completion axillary lymph node dissection (cALND) may be safely omitted, there are a still a number of patients where prediction of non-SLN metastasis may be helpful for cALND decision making. Multiple studies suggest that specific pathologic characteristics of the primary tumor and the SLN metastases are associated with an increased likelihood of additional positive non-SLN. METHODS: This is a retrospective multicentric cohort study of 697 patients with cT1-3N0 breast cancer, who had had intraoperative SLN evaluation by OSNA assay with a cALND. TTL is defined as the amount of CK19 mRNA copies number in all positives SLN (copies/µL). RESULTS: Univariate logistic regression showed that, in addition to TTL (p < 0.001), the number of affected SLNs (p < 0.001), tumor size (p < 0.001), HER2 status (p = 0.007), and lymphovascular invasion (LVI, p < 0.001) were predictive of ALND status. The multivariate logistic regression analysis showed that TTL is an independent predictor of metastatic non-SLNs, after adjusting for the tumor size, HER2 status, LVI and, in particular, the number of affected SLNs. CONCLUSIONS: TTL by OSNA is a newly standardized and automated tool that predicts axillary node status better and independently of the number of affected SLNs and the type of surgery. This value can then help clinicians to personalize surgical treatment. Prospective studies will be carried out to determine the clinical impact of this variable in the management of patients.

Application of segmented analysis via multivariate curve resolution with alternating least squares to 1H-nuclear magnetic resonance spectroscopy to identify different sugar sources.

The different types of sugar employed in the food industry exhibit chemical similarity and are mostly dominated by sucrose. Owing to the sugar origin of and differences in production, the presence of certain minor organic compounds differs. To differentiate between sugars based on their botanical source, geographical origin, or storage conditions, commercial brown sugars and sugar beet extracts were analyzed by 1H NMR spectroscopy applying a segmented analysis by means of multivariate curve resolution-alternating least squares (MCR-ALS). Principal component analysis and partial least squares-discriminant analysis yielded excellent differentiation between sugars from different sources after the application of this preprocessing strategy; without loss of chemical information and with direct interpretation of the results. By applying a segmented analysis via MCR-ALS to 1H NMR sugar data, similar spectroscopic profiles could be differentiated. This improved the selectivity of 1H NMR spectroscopy for sugar source differentiation which can be useful for industrial sugar authentication purposes.

Feasibility and safety of targeted axillary dissection guided by intraoperative ultrasound after neoadjuvant treatment.

BACKGROUND: Axillary management in cN + axillary nodes after neoadjuvant systemic therapy (NST) in breast cancer (BC) remains under research with the aim of de-escalation of axillary node dissection (ALND). Several axillary guided localization techniques have been reported. This study evaluates the safety of intraoperative ultrasound (IOUS) guided targeted axillary dissection (TAD) in a large sample after the results of ILINA trial. MATERIALS: Prospective data have been collected from October 2015 to June 2022 in patients with cT0-T4 and positive axillary lymph nodes (cN1) treated with NST. Before NST, an ultrasound visible marker was placed into the positive node. After NST, IOUS guided TAD was performed including sentinel node biopsy (SLN). Until December 2019, all patients underwent an ALND after TAD procedure. From January 2020, ALND was spared in those patients with an axillary pathological complete response (pCR). RESULTS: 235 patients were included. pCR (ypT0/is ypN0) was achieved in 29% patients. Identification rate (IR) of the clipped node by IOUS was 96% (95% IC, 92.5-98.1%) and IR of SLN was 95% (95% IC, 90.8-97.2%). False negative rate (FNR) for TAD procedure (SLN + clipped node) was 7.0% (95% IC, 2.3-15.7%), which decreased to 4.9% when a total of 3 or more nodes were removed. Axillary ultrasound before surgery assessed residual disease with an AUC of 0.5241. Residual axillary disease tend to be the most significant factor for axillary recurrences. CONCLUSIONS: This study confirms the feasibility, safety and accuracy of IOUS guided surgery for axillary staging after NST in node positive BC patients.

Early-Stage Breast Cancer Detection in Breast Milk.

Breast cancer occurring during pregnancy (PrBC) and postpartum (PPBC) is usually diagnosed at more advanced stages compared with other breast cancer, worsening its prognosis. PPBC is particularly aggressive, with increased metastatic risk and mortality. Thus, effective screening methods to detect early PrBC and PPBC are needed. We report for the first time that cell-free tumor DNA (ctDNA) is present in breast milk (BM) collected from patients with breast cancer. Analysis of ctDNA from BM detects tumor variants in 87% of the cases by droplet digital PCR, while variants remain undetected in 92% of matched plasma samples. Retrospective next-generation sequencing analysis in BM ctDNA recapitulates tumor variants, with an overall clinical sensitivity of 71.4% and specificity of 100%. In two cases, ctDNA was detectable in BM collected 18 and 6 months prior to standard diagnosis. Our results open up the potential use of BM as a new source for liquid biopsy for PPBC detection. SIGNIFICANCE: For the first time, we show that BM obtained from patients with breast cancer carries ctDNA, surpassing plasma-based liquid biopsy for detection and molecular profiling of early-stage breast cancer, even prior to diagnosis by image. See related commentary by Cunningham and Turner, p. 2125. This article is featured in Selected Articles from This Issue, p. 2109.

Extensive nodal involvement increases the positivity of blue nodes in the axillary reverse mapping procedure in patients with breast cancer.

BACKGROUND: The axillary reverse mapping (ARM) technique has been proposed to prevent arm lymphedema. We conducted this study to assess the feasibility of the technique and the outcomes of patients with neoadjuvant chemotherapy (NAC). METHODS: From July 2009 to May 2010, a prospective study was performed in 36 patients with breast cancer undergoing an ALND. The ARM technique was performed injecting 3 cm(3) of Patent Blue in the ipsilateral arm. Of the 36 patients, 29 patients received NAC previously to the ARM and 7 patients had an ALND and ARM performed as first treatment for positive axillary nodes. RESULTS: The identification rate of blue nodes was 83.3% (30 patients). Sentinel lymph node (SLN) was performed in 15 of 29 (42%) patients in the NAC group. Of these 15, two patients (13%) had a concordance between the blue and the hot node. Blue nodes were positive in 4 (13%) of the 30 patients. CONCLUSIONS: The ARM technique is feasible in patients undergoing NAC. Patients with extensive nodal involvement have increased risk of having positive blue nodes. More studies are needed to assess the subgroup of patients with positive axilla that may have the blue node spared without compromising the oncological treatment.

[Mucormycosis. An emergent mycosis]. / Mucormicosis. Una micosis emergente.

Mucormycosis is an opportunistic infection caused by fungi of the order Mucorales. It is characterized by rapid progression and high morbidity and mortality in the absence of early diagnosis and prompt treatment. It was an infrequent disease, but in recent years, its incidence appears to have increased. The aim of this paper is to report the cases of mucormycosis diagnosed from 1982 to 2010 at the Hospital de Clinicas José de San Martín, University of Buenos Aires. We diagnosed 10 cases of mucormycosis; the first three between 1982 and 2004 and the last 7 between 2005 and 2010. The incidence from 1980 to 2004 was 0.13 patient-years and the frequency 0.1/10 000 discharges (95% CI 0.00- 0.3). In the period 2005 to 2010, the incidence was 0.86 patients per year with 1.1/10 000 discharges (95% CI 0.5-2.4). There was a pulmonary mucormycosis case (in a patient treated with corticosteroids) and nine rhinocerebral cases, two in neutropenic and seven in diabetic patients. The diagnosis was made by observation of cenocytic hyphae in 10/10 patients. Mucorales were recovered in 8/9 cultures (5 Rhizopus spp and 3 Mucor spp.). In one case diagnosis of pulmonary mucormycosis was made post-mortem. Nine patients were treated with amphotericin B deoxycholate (in 3 patients supplemented with liposomal amphotericin B) and surgery. Three patients underwent hyperbaric chamber. Seven patients had favorable outcome. In conclusion, mucormycosis is a rare disease, but its incidence has increased over the past five years. A good evolution of the patients is linked to early diagnosis and treatment.

Prognostic value of ctDNA detection in patients with early breast cancer undergoing neoadjuvant therapy: A systematic review and meta-analysis.

Circulating tumor DNA (ctDNA) is increasingly being used as a biomarker in early breast cancer (EBC). We performed a systematic review and meta-analysis to investigate the prognostic value of ctDNA in patients with EBC treated with neoadjuvant therapy (NAT). We searched Medline, Web of Science and Embase for observational or interventional studies that included patients with EBC undergoing NAT, reported outcomes related to the predefined endpoints, and had full text articles available. Study selection followed the PRISMA guidelines and quality assessment the REMARK tool for biomarker studies. Primary endpoint was impact of ctDNA detection in different time points (baseline, on-treatment, and after NAT) on relapse-free survival (RFS) and overall survival (OS). Secondary endpoints included the association of ctDNA detection with pathologic complete response (pCR), and the positive and negative predictive value of ctDNA detection in predicting residual disease after NAT. From the 2908 studies initially identified, 11 met the eligibility criteria and were included in the meta-analysis. Detection of ctDNA, both at baseline and after completion of NAT, significantly associated to worse RFS (HR 4.22, 95% CI: 1.29-13.82 and HR 5.67, 95% CI: 2.73-11.75, respectively) and worse OS (HR 19.1, 95% CI: 6.9-53.04 and HR 4.00, 95% CI: 1.90-8.42, respectively). In contrast, detection of ctDNA did not associate with the probability of achieving a pCR. Our results suggest that ctDNA assessment during NAT for EBC merits further evaluation as a stratification risk factor in prospective trials, in order to better individualize patient's treatment.

Clearance of ctDNA in triple-negative and HER2-positive breast cancer patients during neoadjuvant treatment is correlated with pathologic complete response.

Background: Although the standard of care is to perform surgery of primary breast cancer (BC) after neoadjuvant chemotherapy (NAC), for certain patients achieving clinical complete response (cCR) and pathologic complete response (pCR), omission of surgical treatment may be an option. Levels of circulating tumor DNA (ctDNA) during and after therapy could identify patients achieving minimal residual disease. In this study, we evaluated whether ctDNA clearance during NAC could be a correlate to effective response in human epidermal growth factor receptor 2 positive (HER2+) and triple-negative (TN) BC patients. Methods: A prospective study was conducted to identify patient-specific PIK3CA and TP53 mutations in tissue using next-generation sequencing, which could then be used to track the presence/absence of mutations prior to, during, and following NAC using Sysmex SafeSEQ technology. All patients underwent a surgical excision after NAC, and pCR was assessed. Results: A total of 29 TN and HER2+ BC patients were examined and 20 that carried mutations in the PIK3CA and/or TP53 genes were recruited. Overall, 19 of these 20 patients harbored at least one tumor-specific mutation in their plasma at baseline. After NAC, 15 patients (75.0%) achieved pCR according to the histopathologic evaluation of the surgical specimen, and 15 patients (75.0%) had a cCR; 18 of 20 patients (90.0%) had concordant pCR and cCR. The status of 'no mutation detected' (NMD) following NAC in cCR patients correctly identified the pCR in 14 of 15 patients (93.33%), as well as correctly ruled out pCR in three patients, with an accuracy of 89.47%. During the 12-month follow-up after surgery, 40 plasma samples collected from 15 patients all showed no detectable ctDNA (NMD), and no patient recurred. Conclusion: These findings prompt further research of the value of ctDNA for non-invasive prediction of clinical/pathological response, raising the possibility of sparing surgery following NAC in selected BC patients.

Preclinical In Vivo Validation of the RAD51 Test for Identification of Homologous Recombination-Deficient Tumors and Patient Stratification.

PARP inhibitors (PARPi) are approved drugs for platinum-sensitive, high-grade serous ovarian cancer (HGSOC) and for breast, prostate, and pancreatic cancers (PaC) harboring genetic alterations impairing homologous recombination repair (HRR). Detection of nuclear RAD51 foci in tumor cells is a marker of HRR functionality, and we previously established a test to detect RAD51 nuclear foci. Here, we aimed to validate the RAD51 score cut off and compare the performance of this test to other HRR deficiency (HRD) detection methods. Laboratory models from BRCA1/BRCA2-associated breast cancer, HGSOC, and PaC were developed and evaluated for their response to PARPi and cisplatin. HRD in these models and patient samples was evaluated by DNA sequencing of HRR genes, genomic HRD tests, and RAD51 foci detection. We established patient-derived xenograft models from breast cancer (n = 103), HGSOC (n = 4), and PaC (n = 2) that recapitulated patient HRD status and treatment response. The RAD51 test showed higher accuracy than HRR gene mutations and genomic HRD analysis for predicting PARPi response (95%, 67%, and 71%, respectively). RAD51 detection captured dynamic changes in HRR status upon acquisition of PARPi resistance. The accuracy of the RAD51 test was similar to HRR gene mutations for predicting platinum response. The predefined RAD51 score cut off was validated, and the high predictive value of the RAD51 test in preclinical models was confirmed. These results collectively support pursuing clinical assessment of the RAD51 test in patient samples from randomized trials testing PARPi or platinum-based therapies. SIGNIFICANCE: This work demonstrates the high accuracy of a histopathology-based test based on the detection of RAD51 nuclear foci in predicting response to PARPi and cisplatin.