Upfront Taxane Could Be Superior to Pegylated Liposomal Doxorubicin (PLD): A Retrospective Real-World Analysis of Treatment Sequence Taxane-PLD versus PLD-Taxane in Patients with Metastatic Breast Cancer.

Background: Patients with endocrine-resistant metastatic breast cancer (MBC) require cytostatic therapy. Single-agent taxanes and anthracyclines, including pegylated liposomal doxorubicin (PLD), are standard treatment options. There are no prospective data regarding optimal treatment sequences, and real-world data regarding both treatment options are limited. Methods: We analyzed electronic records of all patients with Her2-negative MBC treated with either first-line PLD or first-line taxane and subsequent crossover at the University Hospital Basel between 2003 and 2021. The primary endpoint was time to next chemotherapy or death (TTNC). Secondary endpoints were overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). We used the Kaplan-Meyer method and logrank test to compare time-to-event endpoints and the Fisher exact test to compare discrete variables. Results: We retrospectively identified 42 patients with Her2-negative MBC who have received either single-agent PLD or single-agent taxane as first-line chemotherapy with subsequent crossover, including 23 patients who received first-line PLD and 19 patients who received first-line taxane. Baseline characteristics were similar between treatment groups. Treatment sequence PLD-taxane was significantly inferior to taxane-PLD regarding all endpoints: median TTNC 4.9 vs. 9.9 months (p = 0.006), median OS 17.8 vs. 24.6 months (p = 0.05), median PFS 4.4 vs. 9.0 months (p = 0.005), and ORR 13% vs. 53% (p = 0.01). Conclusions: Here, we report a first retrospective head-to-head comparison of the treatment sequence PLD-taxane versus taxane-PLD in patients with MBC, showing a substantial advantage of using taxanes first, followed by PLD. An inherent treatment bias in favor of first-line taxanes cannot be excluded, thus calling for prospective validation.

Application of a 21-Gene Recurrence Score in a Swiss Single-Center Breast Cancer Population: A Comparative Analysis of Treatment Administration before and after TAILORx.

In patients with hormone receptor positive, human epidermal receptor 2 negative (HR+/HER2-) negative breast cancer (BC), the TAILORx study showed the benefit of adding chemotherapy (CHT) to endocrine therapy (ET) in a subgroup of patients under 50 years with an intermediate Oncotype DX recurrence score (RS 11-25). The aim of the present study was to determine if the TAILORx findings, including the changes in the RS categories, impacted CHT use in the intermediate RS (11-25) group in daily practice, as well as to identify the main factors for CHT decisions. We conducted a retrospective study on 326 BC patients (59% node-negative), of which 165 had a BC diagnosis before TAILORx (Cohort A) and 161 after TAILORx publication (Cohort B). Changes in the RS categories led to shifts in patient population distribution, thereby leading to a 40% drop in the low RS (from 60% to 20%), which represented a doubling in the intermediate RS (from 30% to 60%) and an increase of 5% in the high RS (from 8-10% to 15%). The overall CHT recommendation and application did not differ significantly between cohort B when compared with A (19% vs. 22%, resp., p = 0.763). In the intermediate RS (11-25), CHT use decreased by 5%, while in the high-risk RS category (>25), there was an increase of 13%. The tumor board recommended CHT for 90% of the patients according to the new RS guidelines in cohort A and for 85% in cohort B. The decision for CHT recommendation was based on age (OR 0.93, 95% CI 0.08-0.97, p = 0.001), nodal stage (OR 4.77, 95% CI 2.03-11.22, p < 0.001), and RS categories (RS 11-25 vs. RS 0-10: OR 0.06 (95% CI 0.02-0.17), p < 0.001; RS > 26 vs. RS 11-25: OR 618.18 95% CI 91.64-4169.91, p < 0.001), but did not depend on the cohort. In conclusion, while the tumor board recommendation for CHT decreased in the intermediate RS category, there was an increase being reported in the high RS category, thus leading to overall minor changes in CHT application. As expected, among the younger women with intermediate RS and unfavorable histopathological factors, CHT use increased.

Multiplexed molecular imaging with surface enhanced resonance Raman scattering nanoprobes reveals immunotherapy response in mice via multichannel image segmentation.

Visualizing the presence and distribution of multiple specific molecular markers within a tumor can reveal the composition of its microenvironment, inform diagnosis, stratify patients, and guide treatment. Raman imaging with multiple molecularly-targeted surface enhanced Raman scattering (SERS) nanoprobes could help investigate emerging cancer treatments preclinically or enable personalized treatment assessment. Here, we report a comprehensive strategy for multiplexed imaging using SERS nanoprobes and machine learning (ML) to monitor the early effects of immune checkpoint blockade (ICB) in tumor-bearing mice. We used antibody-functionalized SERS nanoprobes to visualize 7 + 1 immunotherapy-related targets simultaneously. The multiplexed images were spectrally resolved and then spatially segmented into superpixels based on the unmixed signals. The superpixels were used to train ML models, leading to the successful classification of mice into treated and untreated groups, and identifying tumor regions with variable responses to treatment. This method may help predict treatment efficacy in tumors and identify areas of tumor variability and therapy resistance.

Surgical ovarian suppression for adjuvant treatment in hormone receptor positive breast cancer in premenopausal patients.

OBJECTIVE: Ovarian suppression is recommended to complement endocrine therapy in premenopausal women with breast cancer and high-risk features. It can be achieved by either medical ovarian suppression or therapeutic bilateral salpingo-oophorectomy. Our objective was to evaluate characteristics of patients with stage I-III hormone receptor positive primary breast cancer who underwent bilateral salpingo-oophorectomy at our institution. MATERIALS AND METHODS: Premenopausal women with stage I-III hormone receptor positive primary breast cancer diagnosed between January 2010 and December 2014 were identified from a database. Patients with confirmed BRCA1/2 mutations were excluded. Distribution of characteristics between treatment groups was assessed using χ2 test and univariate logistic regression. A multivariate model was based on factors significant on univariate analysis. RESULTS: Of 2740 women identified, 2018 (74%) received endocrine treatment without ovarian ablation, 516 (19%) received endocrine treatment plus ovarian ablation, and 206 (7.5%) did not receive endocrine treatment. Among patients undergoing ovarian ablation 282/516 (55%) received medical ovarian suppression, while 234 (45%) underwent bilateral salpingo-oophorectomy. By univariate logistic analyses, predictors for ovarian ablation were younger age (OR 0.97), histology (other vs ductal: OR 0.23), lymph node involvement (OR 1.89), higher International Federation of Gynecology and Obstetrics (FIGO) stage (stage II vs I: OR 1.48; stage III vs I: OR 2.86), higher grade (grade 3 vs 1: OR 3.41; grade 2 vs 1: OR 2.99), chemotherapy (OR 1.52), and more recent year of diagnosis (2014 vs 2010; OR 1.713). Only year of diagnosis, stage, and human epidermal growth factor receptor 2 (HER-2) treatment remained significant in the multivariate model. Within the cohort undergoing ovarian ablation, older age (OR 1.05) was associated with therapeutic bilateral salpingo-oophorectomy. Of 234 undergoing bilateral salpingo-oophorectomy, 12 (5%) mild to moderate adverse surgical events were recorded. CONCLUSIONS: Bilateral salpingo-oophorectomy is used frequently as an endocrine ablation strategy. Older age was associated with bilateral salpingo-oophorectomy. Perioperative morbidity was acceptable. Evaluation of long-term effects and quality of life associated with endocrine ablation will help guide patient/provider decision-making.

Surface-enhanced Resonance Raman Scattering Nanoprobe Ratiometry for Detecting Microscopic Ovarian Cancer via Folate Receptor Targeting.

Ovarian cancer represents the deadliest gynecologic malignancy. Most patients present at an advanced stage (FIGO stage III or IV), when local metastatic spread has already occurred. However, ovarian cancer has a unique pattern of metastatic spread, in that tumor implants are initially contained within the peritoneal cavity. This feature could enable, in principle, the complete resection of tumor implants with curative intent. Many of these metastatic lesions are microscopic, making them hard to identify and treat. Neutralizing such micrometastases is believed to be a major goal towards eliminating tumor recurrence and achieving long-term survival. Raman imaging with surface enhanced resonance Raman scattering nanoprobes can be used to delineate microscopic tumors with high sensitivity, due to their bright and bioorthogonal spectral signatures. Here, we describe the synthesis of two 'flavors' of such nanoprobes: an antibody-functionalized one that targets the folate receptor - overexpressed in many ovarian cancers - and a non-targeted control nanoprobe, with distinct spectra. The nanoprobes are co-administered intraperitoneally to mouse models of metastatic human ovarian adenocarcinoma. All animal studies were approved by the Institutional Animal Care and Use Committee of Memorial Sloan Kettering Cancer Center. The peritoneal cavity of the animals is surgically exposed, washed, and scanned with a Raman microphotospectrometer. Subsequently, the Raman signatures of the two nanoprobes are decoupled using a Classical Least Squares fitting algorithm, and their respective scores divided to provide a ratiometric signal of folate-targeted over untargeted probes. In this way, microscopic metastases are visualized with high specificity. The main benefit of this approach is that the local application into the peritoneal cavity - which can be done conveniently during the surgical procedure - can tag tumors without subjecting the patient to systemic nanoparticle exposure. False positive signals stemming from non-specific binding of the nanoprobes onto visceral surfaces can be eliminated by following a ratiometric approach where targeted and non-targeted nanoprobes with distinct Raman signatures are applied as a mixture. The procedure is currently still limited by the lack of a commercial wide-field Raman imaging camera system, which once available will allow for the application of this technique in the operating theater.

DNA-enabled rational design of fluorescence-Raman bimodal nanoprobes for cancer imaging and therapy.

Recently, surface-enhanced Raman scattering nanoprobes have shown tremendous potential in oncological imaging owing to the high sensitivity and specificity of their fingerprint-like spectra. As current Raman scanners rely on a slow, point-by-point spectrum acquisition, there is an unmet need for faster imaging to cover a clinically relevant area in real-time. Herein, we report the rational design and optimization of fluorescence-Raman bimodal nanoparticles (FRNPs) that synergistically combine the specificity of Raman spectroscopy with the versatility and speed of fluorescence imaging. DNA-enabled molecular engineering allows the rational design of FRNPs with a detection limit as low as 5 × 10-15 M. FRNPs selectively accumulate in tumor tissue mouse cancer models and enable real-time fluorescence imaging for tumor detection, resection, and subsequent Raman-based verification of clean margins. Furthermore, FRNPs enable highly efficient image-guided photothermal ablation of tumors, widening the scope of the NPs into the therapeutic realm.

Lysis-independent potentiation of immune checkpoint blockade by oncolytic virus.

Intratumoral therapy with oncolytic viruses is increasingly being explored as a strategy to potentiate an immune response against cancer, but it remains unknown whether such therapy should be restricted to cancers sensitive to virus-mediated lysis. Using Newcastle Disease Virus (NDV) as a model, we explore immunogenic potential of an oncolytic virus in bladder cancer, where existing immunotherapy with PD-1 and PD-L1-targeting antibodies to date has shown suboptimal response rates. Infection of human and mouse bladder cancer cells with NDV resulted in immunogenic cell death, activation of innate immune pathways, and upregulation of MHC and PD-L1 in all tested cell lines, including the cell lines completely resistant to NDV-mediated lysis. In a bilateral flank NDV-lysis-resistant syngeneic murine bladder cancer model, intratumoral therapy with NDV led to an increase of immune infiltration in both treated and distant tumors and a shift from an inhibitory to effector T cell phenotype. Consequently, combination of intratumoral NDV with systemic PD-1 or CTLA-4 blockade led to improved local and abscopal tumor control and overall survival. These findings encourage future clinical trials combining intratumoral NDV therapy with systemic immunomodulatory agents and underscore the rationale for such treatments irrespective of tumor cell sensitivity to NDV-mediated lysis.

Adjuvant chemotherapy in patients with operable granulosa cell tumors of the ovary: a surveillance, epidemiology, and end results cohort study.

Adjuvant chemotherapy is recommended for patients with resected high-risk adult granulosa cell tumors (GCT), although strong data to support this are lacking. The objective of this study was to assess the outcomes of GCT patients, with the specific focus on patients that received adjuvant chemotherapy with curative intent (stage I-III), reported in a large national cancer registry. Data from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2013 were used for analysis. Patient and disease characteristics were extracted and analyzed for association with administration of chemotherapy. Impact on disease-specific survival (DSS) was analyzed using log-rank test. A total of 739 patients with surgically treated adult GCT were identified. Median age was 51 years. 570 (77%) patients were stage I, 87 (12%) were stage II, and 82 (11%) were stage III. Adjuvant chemotherapy was administered to 176 (24%) patients. Young age, higher stage, and hysterectomy were associated with chemotherapy administration. Higher disease stage was associated with decreased five-year DSS (IA/B 98.5%, IC 95.1%, II 86.1%, III 83.5%, P < 0.01). Notably, administration of adjuvant chemotherapy was not associated with improved five-year DSS (P = 0.45) regardless of disease stage (stage IA/B: 96% with chemotherapy vs. 99% without chemotherapy; P = 0.64), (stage IC: 97% with chemotherapy vs. 94% without chemotherapy; P = 0.49), (stage II: 89% with chemotherapy vs. 83% without chemotherapy; P = 0.56), (stage III: 73% with chemotherapy vs. 93% without chemotherapy; P = 0.18). In this analysis, chemotherapy was not found to be associated with improved DSS of patients with operable disease regardless of stage, questioning the role for adjuvant chemotherapy in GCT.

PD-L1 in tumor microenvironment mediates resistance to oncolytic immunotherapy.

Intralesional therapy with oncolytic viruses (OVs) leads to the activation of local and systemic immune pathways, which may present targets for further combinatorial therapies. Here, we used human tumor histocultures as well as syngeneic tumor models treated with Newcastle disease virus (NDV) to identify a range of immune targets upregulated with OV treatment. Despite tumor infiltration of effector T lymphocytes in response to NDV, there was ongoing inhibition through programmed death ligand 1 (PD-L1), acting as a mechanism of early and late adaptive immune resistance to the type I IFN response and T cell infiltration, respectively. Systemic therapeutic targeting of programmed cell death receptor 1 (PD-1) or PD-L1 in combination with intratumoral NDV resulted in the rejection of both treated and distant tumors. These findings have implications for the timing of PD-1/PD-L1 blockade in conjunction with OV therapy and highlight the importance of understanding the adaptive mechanisms of immune resistance to specific OVs for the rational design of combinatorial approaches using these agents.

Pre-existing Immunity to Oncolytic Virus Potentiates Its Immunotherapeutic Efficacy.

Anti-viral immunity presents a major hurdle for systemically administered oncolytic viruses (OV). Intratumoral OV therapy has a potential to overcome this problem through activation of anti-tumor immune response, with local and abscopal effects. However, the effects of anti-viral immunity in such a setting are still not well defined. Using Newcastle Disease Virus (NDV) as a model, we explore the effects of pre-existing anti-viral immunity on therapeutic efficacy in syngeneic mouse tumor models. Unexpectedly, we find that while pre-existing immunity to NDV limits its replication in tumors, tumor clearance, abscopal anti-tumor immune effects, and survival are not compromised and, on the contrary, are superior in NDV-immunized mice. These findings demonstrate that pre-existing immunity to NDV may increase its therapeutic efficacy through potentiation of systemic anti-tumor immunity, which provides clinical rationale for repeated therapeutic dosing and prompts investigation of such effects with other OVs.

MUC1 Aptamer Targeted SERS Nanoprobes.

Recently, surface-enhanced Raman scattering (SERS) nanoprobes (NPs) have shown promise in the field of cancer imaging due to their unparalleled signal specificity and high sensitivity. Here we report the development of a DNA aptamer targeted SERS NP. Recently, aptamers are being investigated as a viable alternative to more traditional antibody targeting due to their low immunogenicity and low cost of production. We developed a strategy to functionalize SERS NPs with DNA aptamers, which target Mucin1 (MUC1) in human breast cancer (BC). Thorough in vitro characterization studies demonstrated excellent serum stability and specific binding of the targeted NPs to MUC1. In order to test their in vivo targeting capability, we co-injected MUC1-targeted SERS NPs, and as controls non-targeted and blocked MUC1-targeted SERS NPs in BC xenograft mouse models. A two-tumor mouse model with differential expression of MUC1 (MDA-MB-468 and MDA-MB-453) was used to control for active versus passive targeting in the same animals. The results showed that the targeted SERS NPs home to the tumors via active targeting of MUC1, with low levels of passive targeting. We expect this strategy to be an advantageous alternative to antibody-based targeting and useful for targeted imaging of tumor extent, progression, and therapeutic response.

Tissue factor-specific ultra-bright SERRS nanostars for Raman detection of pulmonary micrometastases.

Here we demonstrate a novel application of 'surface enhanced resonance Raman scattering nanoparticles' (SERRS NPs) for imaging breast cancer lung metastases with much higher precision than currently feasible. A breast cancer lung metastasis mouse model was established by intravenous injection of LM2 cells. These mice were intravenously administered SERRS NPs conjugated with ALT-836, an anti-tissue factor (TF) monoclonal antibody, and subjected to Raman imaging to visualize the expression of TF both in vivo and ex vivo. Raman imaging indicated marked uptake of αTF-SERRS-NPs by the lung metastases compared to isotype and blocking controls. Conversely, little uptake of αTF-SERRS-NPs was observed in the lungs of healthy mice. Successful detection and delineation of pulmonary micrometastatic lesions as small as 200 µm, corroborated by histology, immunohistochemistry, and bioluminescence imaging confirmed the suitability of both TF as a target and αTF-SERRS-NPs as an effective contrast agent for imaging breast cancer lung metastases. Further advancements of this technique in the form of Raman endoscopes coupled with ultrabright SERRS NPs developed in this work could lead to minimally invasive detection and resection of lung metastases.

Folate-Targeted Surface-Enhanced Resonance Raman Scattering Nanoprobe Ratiometry for Detection of Microscopic Ovarian Cancer.

Ovarian cancer has a unique pattern of metastatic spread, in that it initially spreads locally within the peritoneal cavity. This is in contrast to most other cancer types, which metastasize early on via the bloodstream to distant sites. This unique behavior opens up an opportunity for local application of both therapeutic and imaging agents. Upon initial diagnosis, 75% of patients already present with diffuse peritoneal spread involving abdominal organs. Complete resection of all tumor implants has been shown to be a major factor for improved survival. Unfortunately, it is currently not possible for surgeons to visualize microscopic implants, impeding their removal and leading to tumor recurrences and poor outcomes in most patients. Thus, there is a great need for new intraoperative imaging techniques that can overcome this hurdle. We devised a method that employs folate receptor (FR)-targeted surface-enhanced resonance Raman scattering (SERRS) nanoparticles (NPs), as folate receptors are typically overexpressed in ovarian cancer. We report a robust ratiometric imaging approach using anti-FR-SERRS-NPs (αFR-NPs) and nontargeted SERRS-NPs (nt-NPs) multiplexing. We term this method "topically applied surface-enhanced resonance Raman ratiometric spectroscopy" (TAS3RS ("tasers") for short). TAS3RS successfully enabled the detection of tumor lesions in a murine model of human ovarian adenocarcinoma regardless of their size or localization. Tumors as small as 370 µm were detected, as confirmed by bioluminescence imaging and histological staining. TAS3RS holds promise for intraoperative detection of microscopic residual tumors and could reduce recurrence rates in ovarian cancer and other diseases with peritoneal spread.

Imaging of Liver Tumors Using Surface-Enhanced Raman Scattering Nanoparticles.

Complete surgical resection is the ideal first-line treatment for most liver malignancies. This goal would be facilitated by an intraoperative imaging method that enables more precise visualization of tumor margins and detection of otherwise invisible microscopic lesions. To this end, we synthesized silica-encapsulated surface-enhanced Raman scattering (SERS) nanoparticles (NPs) that act as a molecular imaging agent for liver malignancies. We hypothesized that, after intravenous administration, SERS NPs would avidly home to healthy liver tissue but not to intrahepatic malignancies. We tested these SERS NPs in genetically engineered mouse models of hepatocellular carcinoma and histiocytic sarcoma. After intravenous injection, liver tumors in both models were readily identifiable with Raman imaging. In addition, Raman imaging using SERS NPs enabled detection of microscopic lesions in liver and spleen. We compared the performance of SERS NPs to fluorescence imaging using indocyanine green (ICG). We found that SERS NPs delineate tumors more accurately and are less susceptible to photobleaching. Given the known advantages of SERS imaging, namely, high sensitivity and specific spectroscopic detection, these findings hold promise for improved resection of liver cancer.

Impact of Extended Primary Surgery on Suboptimally Operable Patients With Advanced Ovarian Cancer.

OBJECTIVES: Extensive surgical efforts to achieve an optimal debulking (no residual tumor) in primary surgery of ovarian cancer are today's criterion standard in gyneco-oncologic surgery. However, it is controversial whether extensive surgery, including resections of metastases in the upper abdomen and bowel resections, is justifiable in patients with not completely operable lesions. METHODS: All patients who had undergone surgery for ovarian cancer in the years 2002 to 2013 at our institution were viewed (n = 472). We retrospectively identified 278 operations for primary ovarian cancer. Ninety-six (35%) of the 278 patients showed postoperative tumor residuals and were included in this study. RESULTS: Fifty-five (57%) of 96 patients underwent bowel resection, showing significantly higher complication rates (64% vs 39% minor complications, P = 0.017; 31% vs 9.8% severe complications, P = 0.013) compared with patients without bowel resections as well as no improvement in progression-free or overall survival (median overall survival, 19.5 vs 32.9; P = 0.382). Multiple anastomoses (≥2) were associated with higher rates for anastomotic leakage (16.7% vs 2.6%, P = 0.02) and a higher mortality (16.7% vs 0%, P = 0.04) compared with patients with only 1 anastomosis. Extensive surgery of the upper abdomen was not associated with a significant increase in complication rates. CONCLUSIONS: Because of the increased morbidity of bowel resections without any evidence for improvement of survival, we suggest to restrain from further resection of intestines if an optimal debulking seems not feasible after removal of the major tumor bulk.

Intraoperative Hyperthermic Intraperitoneal Chemotherapy in Patients With Advanced Ovarian Cancer.

Ovarian cancer, because it is largely confined to the peritoneal cavity, has a unique tumor biology and metastatic spread pattern. Its metastatic potential comes from detached tumor cells in the peritoneal cavity that re-attach to the mesothelial lining of the peritoneal surface. It is proposed that these micrometastases without neovasculature, as well as floating malignant cells, are drivers of early recurrence, since they can be neither resected nor adequately treated by systemic chemotherapy. This represents the major rationale for local treatment by means of postoperative intraperitoneal (IP) chemotherapy, which is the standard of care in the United States in patients with advanced-stage ovarian cancer who have minimal residual disease following cytoreductive surgery. An alternative loco-regional treatment strategy is the "HIPEC" procedure--hyperthermic IP chemoperfusion that is performed during the operation immediately following completion of gross tumor resection, and which provides improved tissue penetration and distribution of the chemotherapeutics. However, prospective data are limited and an outcomes benefit has yet to be shown. Here we discuss the advantages and pitfalls of HIPEC, as well as current data and ongoing prospective trials.

Total or subtotal colectomy in patients undergoing surgery for primary or recurrent epithelial ovarian cancer.

BACKGROUND: There is controversy as to whether performing a total or subtotal colectomy is justified in patients with advanced ovarian cancer, given its potential for morbidity and a negative effect on long-term quality of life. The aim of this study was to assess the perioperative complications, mortality and outcomes of patients who underwent total or subtotal colectomy as part of the surgical procedure for primary or recurrent epithelial ovarian cancer. PATIENTS AND METHODS: All patients who had undergone surgery including a total or subtotal colectomy for advanced or recurrent ovarian cancer between 2005 and 2013 at our institution were retrospectively identified. RESULTS: In this time period, 339 patients underwent surgery for epithelial ovarian cancer, which in 11 (3%) patients included a total or subtotal colectomy. Severe grade 3-4 postoperative complications occurred in 3 (27%) patients, and 1 (9%) patient died within 60 days of surgery. CONCLUSION: A total or subtotal colectomy is associated with increased but acceptable morbidity in selected patients undergoing primary cytoreductive surgery. However, in the recurrent/palliative setting, total or subtotal colectomy should be avoided as the prognosis is poor and the morbidity outweighs the clinical benefit.

Preoperative MRI in patients with locoregional recurrent breast cancer: influence on treatment modalities.

RATIONALE AND OBJECTIVES: The purpose of this analysis was to evaluate the impact of preoperative magnetic resonance imaging (MRI) on management in patients with locoregional recurrent breast cancer. MATERIALS AND METHODS: Forty-three patients who underwent treatment for locoregional relapse of breast cancer from 2008 through 2012 were analyzed. All patients underwent both conventional surveillance by mammography, ultrasound, and clinical examination and subsequent bilateral breast MRI. RESULTS: Preoperative MRI detected additional tumor foci in 15 of 43 patients (34.9%). In two cases (4.7%), the diagnosis of occult sites had no influence on the subsequent treatment. Two patients (4.7%) had an unfavorable change of surgical management with unnecessary additional resection of benign foci. Eleven patients benefited from the MRI scan detecting malignant occult lesions (25.6%) resulting in either additional surgical resection or radiotherapy. Patient and tumor characteristics in primary disease did not differ significantly between patients with a favorable impact on surgical management and patients who experienced either no benefit or even disadvantage from MRI scan. CONCLUSIONS: Preoperative breast MRI has a strong impact on the management of locoregional recurrent breast cancer. This study demonstrates that breast MRI is a powerful supplement to conventional diagnostic work-up, both during follow-up or preoperative treatment planning in recurrent disease.