This single-arm, phase II, preoperative window-of-opportunity trial (ClinicalTrials.gov Identifier: NCT03802604) investigated the efficacy and safety of talimogene laherparepvec (T-VEC), an oncolytic virus, with atezolizumab, an anti–PD-L1 antibody, in patients with breast cancer and radiologically and pathologically confirmed residual disease prior to surgery. Eligible patients had triple-negative breast cancer (TNBC) or hormone receptor-positive (HR+)/HER2-negative disease with a high proliferation index (Ki67 ≥ 20%) prior to neoadjuvant chemotherapy. Treatment consisted of one intratumoral injection of T-VEC (10⁶ plaque-forming units [PFU]/mL), followed by four biweekly T-VEC doses (10⁸ PFU/mL) plus atezolizumab (840 mg, intravenously). Among the 28 patients enrolled, 20 patients (71.4%) had HR+/HER2-negative and 8 patients (28.6%) had TNBC. At surgery, 7 patients (26.9%) achieved Residual Cancer Burden (RCB)−0/I (primary endpoint), 12 (46.2%) RCB-II and 7 (26.9%) RCB-III. Safety profile was favorable, with mostly low-grade adverse events and no serious events (secondary endpoint). Therapy induced immune modulation, including increased tumor-infiltrating lymphocytes, elevated PD-L1 expression, and enhanced immune-related gene signatures (exploratory endpoints). The trial met its pre-specified efficacy and safety endpoints. These findings support the feasibility of T-VEC plus atezolizumab as a preoperative immunotherapy approach for managing HER2-negative residual disease post-neoadjuvant chemotherapy and warrant further exploration in larger trials.

Background: Adjuvant radiotherapy and hormonotherapy after breast-conserving surgery (BCS) in ductal carcinoma in situ (DCIS) have been shown to reduce the risk of local recurrence. To predict the risk of ipsilateral breast tumor relapse (IBTR) after BCS, the Memorial Sloan Kettering Cancer Center (MSKCC) developed a nomogram to analyze local recurrence (LR) risk in our cohort and to assess its external validation. Methods: A historical cohort study using data from 296 patients treated for DCIS at the Hospital Clínic of Barcelona was carried out. Patients who had had a mastectomy were excluded from the analysis. Results: The mean age was 58 years (42–75), and the median follow-up time was 10.64 years. The overall local relapse rate was 13.04% (27 patients) during the study period. Actuarial 5- and 10-year IBTR rates were 5.8 and 12.9%, respectively. The external validation of the MSKCC nomogram was performed using a multivariate logistic regression analysis on a total of 207 patients, which did not reach statistical significance in the studied population for predicting LR (p = 0.10). The expression of estrogen receptors was significantly associated with a decreased risk of LR (OR: 0.25; p = 0.004). Conclusions: In our series, the LR rate was 13.4%, which was in accordance with the published series. The MSKCC nomogram did not accurately predict the IBTR in this Spanish cohort of patients treated for DCIS (p = 0.10).

Purpose: To describe the magnetic resonance characteristics of radial scars/complex sclerosing lesions (RS/CSL) of the breast using the current BI-RADS lexicon. To investigate the value of diffusion weighted imaging to predict malignancy. Patients and methods: From 2010 to 2017, we have found 25 women with architectural distortion at mammography who underwent surgical resection with a final hystopathologic report of RS/CSL. For the description of MRI findings, we adhered to BI-RADS classification (5th edition). Results: The final pathological diagnosis was: “pure” RS/CSL in 7 cases (28%), RS/CSL with associated high risk lesions in 12 (48%) and 6 cases (24%) were associated with malignancy. Magnetic resonance findings: four of 25 negative or focus. Five of 25 mass enhancement: irregular, non circumscribed spiculated mass with heterogeneous or rim enhancement and most with type II curves. Sixteen of 25 non mass enhancement: focal or linear distribution and heterogeneous internal enhancement most with type I curves. Six of 25 had cancer associated with the complex sclerosing lesion. All six showed non-mass enhancement. Two cases with invasive breast carcinoma had ADC values under 1.15 x10−3 mm/s while most of the rest had the values above. Conclusion: Most RS/CSL showed enhancement at MR. The predominant pattern was a non-mass, focal, heterogeneous internal enhancement with type 1 curves. All cases with associated cancer showed non mass enhancement. Invasive breast cancers had ADC values < 1.15 10-3 s/mm2.

Background/Objectives: The aim of the study was to determine the clinical value of the sentinel lymph node ratio (SLN-R) in predicting additional positive lymph nodes during axillary lymph node dissection (ALND) in breast cancer patients following neoadjuvant chemotherapy (NAC). Methods: A cross-sectional study was performed at a single institution evaluating data from 1521 BC patients. Inclusion criteria comprised cT1/cT4, cN0/cN1 status with positive post-NAC axillary staging by SLN/TAD, respectively, and subsequent ALND. Results: The study included 118 patients, divided into two groups based on the presence or absence of additional node metastasis at ALND: 39 in the residual disease group (RD) and 79 in the non-residual disease group (nRD). Univariate logistic regression analysis of SLN-R was conducted to assess its predictive value, yielding an odds ratio (OR) of 7.79 (CI 1.92–29.5, p = 0.003). An SLN-R cut-off point of <0.35 was identified using ROC curve analysis, with a false-negative rate of 10.2%, as a predictor for no additional metastasis at ALND following post-NAC SLN/TAD positivity. Conclusions: The study concludes that SLN-R is a valuable predictor for determining the omission of ALND in cases where SLN/TAD is positive after NAC. This metric, in combination with other clinical variables, could help develop a nomogram to spare patients from ALND.