Transcriptomic characterization of the histopathological growth patterns in breast cancer liver metastases.

Metastatic breast cancer (mBC) remains incurable and liver metastases (LM) are observed in approximately 50% of all patients with mBC. In some cases, surgical resection of breast cancer liver metastases (BCLM) is associated with prolonged survival. However, there are currently no validated marker to identify these patients. The interactions between the metastatic cancer cells and the liver microenvironment result in two main histopathological growth patterns (HGP): replacement (r-HGP), characterized by a direct contact between the cancer cells and the hepatocytes, and desmoplastic (d-HGP), in which a fibrous rim surrounds the tumor cells. In patients who underwent resection of BCLM, the r-HGP is associated with a worse postoperative prognosis than the d-HGP. Here, we aim at unraveling the biological differences between these HGP within ten patients presenting both HGP within the same metastasis. The transcriptomic analyses reveal overexpression of genes involved in cell cycle, DNA repair, vessel co-option and cell motility in r-HGP while angiogenesis, wound healing, and several immune processes were found overexpressed in d-HGP LM. Understanding the biology of the LM could open avenues to refine treatment of BC patients with LM.

Fluorescence imaging for real-time detection of breast cancer tumors using IV injection of indocyanine green with non-conventional imaging: a systematic review of preclinical and clinical studies of perioperative imaging technologies.

BACKGROUND: This review summarizes the available data on the effectiveness of indocyanine green fluorescence imaging (ICG-FI) for real-time detection of breast cancer (BC) tumors with perioperative imaging technologies. METHODS: PubMed and Scopus databases were exhaustively searched for publications on the use of the real-time ICG-FI evaluation of BC tumors with non-conventional breast imaging technologies. RESULTS: Twenty-three studies were included in this review. ICG-FI has been used for BC tumor identification in 12 orthotopic animal tumor experiences, 4 studies on animal assessment, and for 7 human clinical applications. The BC tumor-to-background ratio (TBR) was 1.1-8.5 in orthotopic tumor models and 1.4-3.9 in animal experiences. The detection of primary human BC tumors varied from 40% to 100%. The mean TBR reported for human BC varied from 2.1 to 3.7. In two studies evaluating BC surgical margins, good sensitivity (93.3% and 100%) and specificity (60% and 96%) have been reported, with a negative predictive value of ICG-FI to predict margin involvement intraoperatively of 100% in one study. CONCLUSIONS: The use of ICG-FI as a guiding tool for the real-time identification of BC tumors and for the assessment of tumor boundaries is promising. There is great variability between the studies with regard to timing and dose. Further evidence is needed to assess whether ICG-guided BC surgery may be implemented as a standard of care.

Treatment Response, Tumor Infiltrating Lymphocytes and Clinical Outcomes in Inflammatory Breast Cancer-Treated with Neoadjuvant Systemic Therapy.

Inflammatory breast cancer (IBC) is a rare (1%-5%), aggressive form of breast cancer, accounting for approximately 10% of breast cancer mortality. In the localized setting, standard of care is neoadjuvant chemotherapy (NACT) ± anti-HER2 therapy, followed by surgery. Here we investigated associations between clinicopathologic variables, stromal tumor-infiltrating lymphocytes (sTIL), and pathologic complete response (pCR), and the prognostic value of pCR. We included 494 localized patients with IBC treated with NACT from October 1996 to October 2021 in eight European hospitals. Standard clinicopathologic variables were collected and central pathologic review was performed, including sTIL. Associations were assessed using Firth logistic regression models. Cox regressions were used to evaluate the role of pCR and residual cancer burden (RCB) on disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS). Distribution according to receptor status was as follows: 26.4% estrogen receptor negative (ER-)/HER2-; 22.0% ER-/HER2+; 37.4% ER+/HER2-, and 14.1% ER+/HER2+. Overall pCR rate was 26.3%, being highest in the HER2+ groups (45.9% for ER-/HER2+ and 42.9% for ER+/HER2+). sTILs were low (median: 5.3%), being highest in the ER-/HER2- group (median: 10%). High tumor grade, ER negativity, HER2 positivity, higher sTILs, and taxane-based NACT were significantly associated with pCR. pCR was associated with improved DFS, DRFS, and OS in multivariable analyses. RCB score in patients not achieving pCR was independently associated with survival. In conclusion, sTILs were low in IBC, but were predictive of pCR. Both pCR and RCB have an independent prognostic role in IBC treated with NACT. SIGNIFICANCE: IBC is a rare, but very aggressive type of breast cancer. The prognostic role of pCR after systemic therapy and the predictive value of sTILs for pCR are well established in the general breast cancer population; however, only limited information is available in IBC. We assembled the largest retrospective IBC series so far and demonstrated that sTIL is predictive of pCR. We emphasize that reaching pCR remains of utmost importance in IBC.

First-in-human study of SBRT and adenosine pathway blockade to potentiate the benefit of immunochemotherapy in early-stage luminal B breast cancer: results of the safety run-in phase of the Neo-CheckRay trial.

BACKGROUND: Luminal B breast cancer (BC) presents a worse prognosis when compared with luminal A BC and exhibits a lower sensitivity to chemotherapy and a lower immunogenicity in contrast to non-luminal BC subtypes. The Neo-CheckRay clinical trial investigates the use of stereotactic body radiation therapy (SBRT) directed to the primary tumor in combination with the adenosine pathway inhibitor oleclumab to improve the response to neo-adjuvant immuno-chemotherapy in luminal B BC. The trial consists of a safety run-in followed by a randomized phase II trial. Here, we present the results of the first-in-human safety run-in. METHODS: The safety run-in was an open-label, single-arm trial in which six patients with early-stage luminal B BC received the following neo-adjuvant regimen: paclitaxel q1w×12 → doxorubicin/cyclophosphamide q2w×4; durvalumab (anti-programmed cell death receptor ligand 1 (PD-L1)) q4w×5; oleclumab (anti-CD73) q2w×4 → q4w×3 and 3×8 Gy SBRT to the primary tumor at week 5. Surgery must be performed 2-6 weeks after primary systemic treatment and adjuvant therapy was given per local guidelines, RT boost to the tumor bed was not allowed. Key inclusion criteria were: luminal BC, Ki67≥15% or histological grade 3, MammaPrint high risk, tumor size≥1.5 cm. Primary tumor tissue samples were collected at three timepoints: baseline, 1 week after SBRT and at surgery. Tumor-infiltrating lymphocytes, PD-L1 and CD73 were evaluated at each timepoint, and residual cancer burden (RCB) was calculated at surgery. RESULTS: Six patients were included between November 2019 and March 2020. Median age was 53 years, range 37-69. All patients received SBRT and underwent surgery 2-4 weeks after the last treatment. After a median follow-up time of 2 years after surgery, one grade 3 adverse event (AE) was reported: pericarditis with rapid resolution under corticosteroids. No grade 4-5 AE were documented. Overall cosmetical breast evaluation after surgery was 'excellent' in four patients and 'good' in two patients. RCB results were 2/6 RCB 0; 2/6 RCB 1; 1/6 RCB 2 and 1/6 RCB 3. CONCLUSIONS: This novel treatment combination was considered safe and is worth further investigation in a randomized phase II trial. TRIAL REGISTRATION NUMBER: NCT03875573.

Histopathological growth patterns and tumor-infiltrating lymphocytes in breast cancer liver metastases.

Liver is the third most common organ for breast cancer (BC) metastasis. Two main histopathological growth patterns (HGP) exist in liver metastases (LM): desmoplastic and replacement. Although a reduced immunotherapy efficacy is reported in patients with LM, tumor-infiltrating lymphocytes (TIL) have not yet been investigated in BCLM. Here, we evaluate the distribution of the HGP and TIL in BCLM, and their association with clinicopathological variables and survival. We collect samples from surgically resected BCLM (n = 133 patients, 568 H&E sections) and post-mortem derived BCLM (n = 23 patients, 97 H&E sections). HGP is assessed as the proportion of tumor liver interface and categorized as pure-replacement ('pure r-HGP') or any-desmoplastic ('any d-HGP'). We score the TIL according to LM-specific guidelines. Associations with progression-free (PFS) and overall survival (OS) are assessed using Cox regressions. We observe a higher prevalence of 'any d-HGP' (56%) in the surgical samples and a higher prevalence of 'pure r-HGP' (83%) in the post-mortem samples. In the surgical cohort, no evidence of the association between HGP and clinicopathological characteristics is observed except with the laterality of the primary tumor (p value = 0.049) and the systemic preoperative treatment before liver surgery (p value = .039). TIL is less prevalent in 'pure r-HGP' as compared to 'any d-HGP' (p value = 0.001). 'Pure r-HGP' predicts worse PFS (HR: 2.65; CI: (1.45-4.82); p value = 0.001) and OS (HR: 3.10; CI: (1.29-7.46); p value = 0.011) in the multivariable analyses. To conclude, we demonstrate that BCLM with a 'pure r-HGP' is associated with less TIL and with the worse outcome when compared with BCLM with 'any d-HGP'. These findings suggest that HGP could be considered to refine treatment approaches.

Histopathological growth pattern of liver metastases as an independent marker of metastatic behavior in different primary cancers.

Surgical resection can lead to prolonged survival in patients with isolated liver metastases (LM) from various primary cancers. However, there are currently no validated predictive markers to discriminate between these oligo/argometastatic patients, who will benefit from surgery, and those with diffuse metastatic behavior in whom surgery will be futile. To evaluate whether the tumor microenvironment, or histopathological growth pattern (HGP), of LM reflects the type of metastatic progression independently of the origin of the primary cancer, we analyzed a combined series of patients who underwent surgery for colorectal LM (N=263) or non-colorectal LM (N=66). HGPs of LM were scored in each patient to distinguish between desmoplastic HGP (all LM showing a complete encapsulated pattern) and non-desmoplastic HGP (at least one LM with some infiltrating-replacement component). In the entire series, 5-year overall and progression-free survival were, 44.5% and 15.5%, respectively, with no significant differences between colorectal and non-colorectal LM. In patients with desmoplastic HGP, 5-year overall and progression-free survival were 57% and 32%, respectively, as compared to 41% and 12%, respectively, in patients with non-desmoplastic-HGP (p=0.03 and 0.005). Irrespective of cancer origin and compared to traditional risk factors, desmoplastic HGP was the most significant predictor for better post-operative overall survival (adjusted HR: 0.62; 95% CI: [0.49-0.97]; p=0.035) and progression-free survival (adjusted HR: 0.61; 95% CI: [0.42-0.87], p=0.006). This suggests that the HGP of LM may represent an accurate marker that reflects the mode of metastatic behavior, independently of primary cancer type.

Paclitaxel plus carboplatin and durvalumab with or without oleclumab for women with previously untreated locally advanced or metastatic triple-negative breast cancer: the randomized SYNERGY phase I/II trial.

Chemo-immunotherapy is the first-line standard of care for patients with PD-L1 positive metastatic triple-negative breast cancer (mTNBC). SYNERGY (NCT03616886) is a dose-finding phase I and a randomized phase II, open-label trial evaluating if targeting the immunosuppressive adenosine pathway can enhance the antitumor activity of chemo-immunotherapy. The phase I part included 6 patients with untreated locally-advanced or mTNBC to determine the safety and recommended phase II dose of the anti-CD73 antibody oleclumab in combination with the anti-PD-L1 durvalumab and 12 cycles of weekly carboplatin and paclitaxel. In the phase II part, 127 women were randomized 1:1 to receive chemo-immunotherapy, with (arm A) or without (arm B) oleclumab. The primary endpoint was the clinical benefit rate at week 24, defined as stable disease, partial or complete response per RECIST v1.1. Secondary endpoints included objective response rate, duration of response, survival outcomes (progression-free survival and overall survival), and safety. The trial did not meet its primary endpoint, as the 24-week clinical benefit rate was not significantly improved by adding oleclumab (43% vs. 44%, p = 0.61). Exploratory median progression-free survival was 5.9 months in arm A as compared to 7.0 months in arm B (p = 0.90). The safety profile was manageable in both arms.

Initial interactions with the FDA on developing a validation dataset as a medical device development tool.

Quantifying tumor-infiltrating lymphocytes (TILs) in breast cancer tumors is a challenging task for pathologists. With the advent of whole slide imaging that digitizes glass slides, it is possible to apply computational models to quantify TILs for pathologists. Development of computational models requires significant time, expertise, consensus, and investment. To reduce this burden, we are preparing a dataset for developers to validate their models and a proposal to the Medical Device Development Tool (MDDT) program in the Center for Devices and Radiological Health of the U.S. Food and Drug Administration (FDA). If the FDA qualifies the dataset for its submitted context of use, model developers can use it in a regulatory submission within the qualified context of use without additional documentation. Our dataset aims at reducing the regulatory burden placed on developers of models that estimate the density of TILs and will allow head-to-head comparison of multiple computational models on the same data. In this paper, we discuss the MDDT preparation and submission process, including the feedback we received from our initial interactions with the FDA and propose how a qualified MDDT validation dataset could be a mechanism for open, fair, and consistent measures of computational model performance. Our experiences will help the community understand what the FDA considers relevant and appropriate (from the perspective of the submitter), at the early stages of the MDDT submission process, for validating stromal TIL density estimation models and other potential computational models. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Axillary Surgical Attitude Changing with Retrospective Application of ACOSOG Z0011 Eligible Criteria: An Institutional Evaluation.

Objective: Sentinel lymph node biopsy (SLNB) represents the gold standard for axillary surgical staging. The aim of this study was to assess the proportion of axillary lymph node dissection (ALND) that could be avoided after retrospective application of the ACOSOG Z0011 criteria and to evaluate the shortterm complications associated with axillary surgery. Materials and Methods: We reviewed breast cancer (BC) patients treated by primary breast-conserving surgery from 2012 to 2015. The percentage of SLNB vs ALND performed before and after the application of the ACOSOG Z0011 criteria was calculated. Complications were analyzed using crosstabs, with p<0.05 considered significant. Results: Two hundred fifty one patients with a median age of 59.3 years were included. BC tumors had a median size of 13 mm and were mostly unifocal (83.9%). There were 30.3% with 1-2 metastatic lymph nodes (MLN). ALND was performed in 44.2%. The patients with 1-2 MLN, had only SLNB in 14.5% of cases. By applying the ACOSOG Z0011 criteria, ALND would have been avoided in 40.2% of patients. At least one postoperative complication was reported after SLNB or ALND for 45.7% and 74.7% of patients respectively. Seroma was the most frequent complication, and occurred in 29.3% of cases after SLNB and in 59.5% after ALND. Conclusion: SNLB is the most commonly used axillary surgical staging procedure in this series (55.8%). With a retrospective application of the ACOSOG Z0011 criteria in our population, ALND could have been avoided for 40.2% patients. Post-operative complications rate was higher after ALND, with a seroma rate at 59.5%.

Association of body mass index with clinicopathological features and survival in patients with primary invasive lobular breast cancer.

PURPOSE: Invasive lobular carcinoma (ILC) represents up to 15% of all breast carcinomas. While the proportion of women with overweight and obesity increases globally, the impact of body mass index (BMI) at primary diagnosis on clinicopathological features of ILC and the prognosis of the patients has not been investigated yet. PATIENTS AND METHODS: We performed a multicentric retrospective study including patients diagnosed with non-metastatic pure ILC. The association of BMI at diagnosis with clinicopathological variables was assessed using linear or multinomial logistic regression. Univariable and multivariable survival analyses were performed to evaluate the association of BMI with disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS). RESULTS: The data of 2856 patients with ILC and available BMI at diagnosis were collected, of which 2570/2856 (90.0%) had oestrogen receptor (ER)-positive and human epidermal growth factor receptor (HER2) not amplified/overexpressed (ER+/HER2-) ILC. Of these 2570 patients, 80 were underweight (3.1%), 1410 were lean (54.9%), 712 were overweight (27.7%), and 368 were obese (14.3%). Older age at diagnosis, a higher tumour grade, a larger tumour size, a nodal involvement, and multifocality were associated with a higher BMI. In univariable models, higher BMI was associated with worse outcomes for all end-points (DFS: hazard ratio (HR) 1.21, 95CI 1.12-1.31, p value<0.01; DRFS: HR 1.25, 95CI 1.12-1.40, p value<0.01; OS: HR 1.25, 95CI 1.13-1.37, p value<0.01). This association was not statistically significant in multivariable analyses (DFS: HR 1.09, 95CI 0.99-1.20, p value 0.08; DRFS: HR 1.03, 95CI 0.89-1.20, p value 0.67; OS: HR 1.11, 95CI 0.99-1.24, p value 0.08), whereas grade, tumour size, and nodal involvement were still prognostic for all end-points. CONCLUSION: Worse prognostic factors such as higher grade, larger tumour size, and nodal involvement are associated with higher BMI in ER+/HER2- ILC, while there was no statistical evidence for an independent prognostic role for BMI. Therefore, we hypothesise that the effect of BMI on survival could be mediated through its association with these clinicopathological variables.

Association between primary tumor characteristics and histopathological growth pattern of liver metastases in colorectal cancer.

INTRODUCTION: The microarchitecture of liver metastases (LMs), or histopathological growth pattern (HGP), has been demonstrated to be a significant prognostic factor in patients undergoing resection of colorectal liver metastases (CRLMs). Currently, however, HGP can be only determined on the operative specimen. Therefore, the development of new tools to predict the HGP of CRLMs before surgery and to understand the mechanisms that drive these patterns is important for improving individualization of therapeutic management. In this study, we analyzed data from a retrospective series of patients who underwent surgery for CRLMs to compare primary tumor characteristics, including markers of local aggressiveness and migratory capacity, and HGP of liver metastases. METHODS: Data from a retrospective series of 167 patients who underwent curative-intent resection of CRLMs and in whom pathological samples from both primary tumor and liver metastases were available were reviewed. At the primary tumor level, KRAS mutational status, grade of differentiation, and tumor budding were assessed. HGP was scored in each resected CRLM, according to consensus guidelines, and classified as desmoplastic (dHGP) or non-desmoplastic (non-dHGP). Associations between primary tumor characteristics and HGP of CRLMs were evaluated using a binary logistic regression model. Overall survival and disease-free survival were evaluated using Kaplan-Meier and multivariable Cox regression analyses. RESULTS: CRLMs were classified as dHGP in 36% of the patients and as non-dHGP in 64%. Higher rates of moderately or poorly differentiated primary tumors were observed in the non-dHGP CRLM group (80%), as compared with the dHGP group (60%) (OR = 3.6; 95%CI: 1.6-7.05; p = 0.001). Higher rates of tumor budding were observed in the non-dHGP CRLM group, with a median tumor budding value of 4 as compared with 2.5 in the dHGP group (p = 0.042). In the entire series, 5-year overall and disease-free survival were 43% and 32.5%, respectively. The non-dHGP CRLM group had worse post-hepatectomy survival, with 5-year overall and disease-free survival of 32.2% and 24.6%, respectively, as compared with 60.8% and 45.9%, respectively, for the dHGP group (p = 0.02). CONCLUSION: Colorectal tumors with moderate or poor differentiation and those with high tumor budding are more frequently associated with CRLMs with a non-dHGP. This suggests that primary tumor characteristics of local aggressiveness and migratory capacity could preferentially promote the development of CRLMs with an infiltrating pattern and that these parameters should be considered as part of new scores for predicting HGP before surgery. This finding may stimulate new lines of research for more individualized therapeutic decision in patients with CRLM candidate to surgery.

Effectiveness of Carbon Localization for Invasive Breast Cancer: An Institutional Experience.

Introduction: The final oncological and aesthetic results of breast-conserving surgery (BCS) are influenced by the precise localization of breast cancer (BC) tumors and by the quality of the intraoperative margin assessment technique. This study aimed to assess the effectiveness of the carbon localization (CL) technique by determining the success rate of BC identification and the proportion of adequate complete resection of BC lesions. Methods: We conducted a cross-sectional retrospective study of patients treated with primary BCS for invasive BC who underwent CL of their BC lesion at the Jules Bordet Institute between January 2015 and December 2017. Descriptive statistics with categorical and continuous variables were used. The success rate of tumor identification and the rate of adequate excision were calculated using the test of percentages for independent dichotomous data. Results: This study included 542 patients with 564 nonpalpable BC lesions. The median pathological tumor size was 12 mm. Of these, 460 were invasive ductal carcinomas. Most of the tumors were of the luminal subtype. CL was performed using ultrasound guidance in 98.5% of cases. The median delay between CL and surgery was 5 days, with 46% of the patients having CL one day before surgery. The lumpectomy weighed 38 g on average, with a median diameter of the surgical sample at 6 cm and a median volume of 44 cm3 (6-369). One-stage complete resection was successfully performed in 93.4% of cases. In 36% of cases, an intraoperative re-excision was performed, based on intraoperative macroscopic pathological margin evaluation. The tumor was identified in 98.9% of cases in the breast surgical specimen. Conclusion: This study demonstrated high success rates for BC tumor identification (99%) and one-stage complete resection (93.4%) after BCS and CL. These results show that CL is an effective, simple, and inexpensive localization technique for successful excision of BC lesions during BCS.

PIK3CA copy-number gain and inhibitors of the PI3K/AKT/mTOR pathway in triple-negative breast cancer.

As wider insights are gained on the molecular landscape of triple-negative breast cancer (TNBC), novel targeted therapeutic strategies might become an option in this setting as well. Activating mutations of PIK3CA represent the second most common alteration in TNBC after the TP53 mutation, with a prevalence of ∼10%-15%. Considering the well-established predictive role of PIK3CA mutations for response to agents targeting the PI3K/AKT/mTOR pathway, several clinical trials are currently evaluating these drugs in patients with advanced TNBC. However, much less is known regarding the actionability of PIK3CA copy-number gains, which represent a thoroughly common molecular alteration in TNBC, with a prevalence estimated at 6%-20%, and are listed as "likely gain-of-function" alterations in the OncoKB database. In the present paper, we describe two clinical cases in which patients harboring PIK3CA-amplified TNBC received a targeted treatment with the mTOR-inhibitor everolimus and the PI3K-inhibitor alpelisib, respectively, with evidence of disease response on 18F-FDG positron-emission tomography (PET) imaging. Hence, we discuss the evidence presently available regarding a possible predictive value of PIK3CA amplification for response to targeted treatment strategies, suggesting that this molecular alteration might represent an intriguing biomarker in this sense. Considering that few of the currently active clinical trials assessing agents targeting the PI3K/AKT/mTOR pathway in TNBC select patients based on tumor molecular characterization, and none of these based on PIK3CA copy-number status, we urge for the introduction of PIK3CA amplification as a criterion for patient selection in future clinical trials in this setting.

HER2 Amplification in p53-Mutated Endometrial Carcinomas.

p53-mutated endometrial carcinomas tend to recur and develop distant metastases. Therefore, the detection of new potential therapeutic targets such as HER2 is particularly interesting. In this retrospective study, which considered over 118 endometrial carcinomas, the p53 mutation was detected in 29.6% of cases. In these cases, the HER2 protein profile was studied via immunohistochemistry, and an overexpression of HER2 protein (++ or +++) was noted in 31.4%. The CISH technique was used in these cases to determine if gene amplification was present. In 18% of cases, the technique was not conclusive. Amplification of the HER2 gene was observed in 36.3% of cases and 36.3% of cases showed a polysomal-like aneusomy for centromere 17. Amplification was found in serous carcinomas, clear cell carcinomas and carcinosarcomas, highlighting the future potentiality of HER2-targeted therapies in these variants of aggressive carcinomas.

Tumor biology reflected by histological growth pattern is more important than surgical margin for the prognosis of patients undergoing resection of colorectal liver metastases.

INTRODUCTION: The histological growth pattern (HGP) of colorectal liver metastases (CRLMs) reflects tumor biology and local infiltrating behavior. In patients undergoing surgery for CRLMs, we investigated whether HGP and surgical margin status interact when influencing prognosis. METHODS: Clinicopathological data, margin status, and HGP were reviewed in patients who underwent resection of CRLMs. R1 margin was defined when cancer cells were present at any point along the margin. HGPs were scored according to international guidelines, identifying patients with desmoplastic (DHGP) or non-desmoplastic (non-DHGP) CRLMs. RESULTS: Among 299 patients, 16% had R1 resection and 81% had non-DHGP CRLMs. Non-DHGP was the only predictive factor for R1 resection (18.7% versus 7.4% in DHGP, p = 0.04). Poorer 5-year overall survival was observed in both R1 and non-DHGP groups in univariate analysis (27.6% in R1 versus 45.6% in R0, p = 0.026, and 37.2% in non-DHGP versus 59.2% in DHGP, p = 0.013), whereas non-DHGP but not R1 remained associated with worse prognosis in multivariate analysis. In patients with non-DHGP, R1 margin has no prognostic impact. CONCLUSIONS: In patients undergoing resection of CRLMs, the prognostic value of poor tumor biology, such as in patients with non-DHGP, exceeds that of surgical radicality.

Circulating Tumor DNA After Neoadjuvant Chemotherapy in Breast Cancer Is Associated With Disease Relapse.

PURPOSE: Detection of circulating tumor DNA (ctDNA) after neoadjuvant chemotherapy in patients with early-stage breast cancer may allow for early detection of relapse. In this study, we analyzed ctDNA using a personalized, tumor-informed multiplex polymerase chain reaction-based next-generation sequencing assay. METHODS: Plasma samples (n = 157) from 44 patients were collected before neoadjuvant therapy (baseline), after neoadjuvant therapy and before surgery (presurgery), and serially postsurgery including a last follow-up sample. The primary end point was event-free survival (EFS) analyzed using Cox regression models. RESULTS: Thirty-eight (86%), 41 (93%), and 38 (86%) patients had baseline, presurgical, and last follow-up samples, respectively. Twenty patients had hormone receptor-positive/human epidermal growth factor receptor 2-negative, 13 had triple-negative breast cancer, and 11 had human epidermal growth factor receptor 2-positive disease. Baseline ctDNA detection was observed in 22/38 (58%) patients and was significantly associated with Ki67 > 20% (P = .036) and MYC copy-number gain (P = .0025, false discovery rate = 0.036). ctDNA detection at presurgery and at last follow-up was observed in 2/41 (5%) and 2/38 (5%) patients, respectively. Eight relapses (seven distant and one local) were noted (median follow-up 3.03 years [range, 0.39-5.85 years]). After adjusting for pathologic complete response (pCR), ctDNA detection at presurgery and at last follow-up was associated with shorter EFS (hazard ratio [HR], 53; 95% CI, 4.5 to 624; P < .01, and HR, 31; 95% CI, 2.7 to 352; P < .01, respectively). Association between baseline detection and EFS was not observed (HR, 1.4; 95% CI, 0.3 to 5.9; P = .67). CONCLUSION: The presence of ctDNA after neoadjuvant chemotherapy is associated with relapse in early-stage breast cancer, supporting interventional trials for testing the clinical utility of ctDNA monitoring in this setting.

Results of a worldwide survey on the currently used histopathological diagnostic criteria for invasive lobular breast cancer.

Invasive lobular carcinoma (ILC) represents the second most common subtype of breast cancer (BC), accounting for up to 15% of all invasive BC. Loss of cell adhesion due to functional inactivation of E-cadherin is the hallmark of ILC. Although the current world health organization (WHO) classification for diagnosing ILC requires the recognition of the dispersed or linear non-cohesive growth pattern, it is not mandatory to demonstrate E-cadherin loss by immunohistochemistry (IHC). Recent results of central pathology review of two large randomized clinical trials have demonstrated relative overdiagnosis of ILC, as only ~60% of the locally diagnosed ILCs were confirmed by central pathology. To understand the possible underlying reasons of this discrepancy, we undertook a worldwide survey on the current practice of diagnosing BC as ILC. A survey was drafted by a panel of pathologists and researchers from the European lobular breast cancer consortium (ELBCC) using the online tool SurveyMonkey®. Various parameters such as indications for IHC staining, IHC clones, and IHC staining procedures were questioned. Finally, systematic reporting of non-classical ILC variants were also interrogated. This survey was sent out to pathologists worldwide and circulated from December 14, 2020 until July, 1 2021. The results demonstrate that approximately half of the institutions use E-cadherin expression loss by IHC as an ancillary test to diagnose ILC and that there is a great variability in immunostaining protocols. This might cause different staining results and discordant interpretations. As ILC-specific therapeutic and diagnostic avenues are currently explored in the context of clinical trials, it is of importance to improve standardization of histopathologic diagnosis of ILC diagnosis.

The association between adiposity and anti-proliferative response to neoadjuvant endocrine therapy with letrozole in post-menopausal patients with estrogen receptor positive breast cancer.

The impact of adiposity on the efficacy of endocrine treatment in patients with estrogen receptor positive breast cancer is poorly investigated. Here, we retrospectively investigated in a cohort of 56 patients whether body mass index and/or mammary adiposity are associated with anti-proliferative response in the neoadjuvant setting. Anti-proliferative response was defined as high Ki67 at baseline (Ki67bl) and low Ki67 at surgery (Ki67srg), using the 14% cut-off. Mammary adipocyte size was assessed on hematoxylin and eosin slides from the surgical samples using digital pathology. A higher proportion of tumors with an anti-proliferative response was observed in patients with obesity (54.5%) as compared to patients with normal weight (9.0%) and patients with overweight (40.0%) (p = 0.031), confirmed by multivariable regression analysis adjusted for baseline Ki67 (OR, obese vs normal weight: 13.76, 95%CI: 1.49-207.63, p = 0.020). Larger adipocyte diameter was identified as predictor of anti-proliferative response (OR per increase in diameter of 5 µm for adipocytes distant from the tumor: 2.24, 95%CI: 1.01-14.32, p = 0.046). This study suggests that anti-proliferative response to neoadjuvant letrozole might be more frequent in patients with increased systemic or mammary adiposity.

Timing evolution of lobular breast cancer through phylogenetic analysis.

BACKGROUND: Late distant recurrence is a challenge for the treatment of invasive lobular carcinoma (ILC) of the breast. Despite in-depth characterisation of primary ILC, the molecular landscape of metastatic ILC is still only partially understood. METHODS: We retrospectively identified 38 ILC patients from the tissue banks of six European institutions. DNA extracted from patient matched primary and metastatic FFPE tissue blocks was whole genome sequenced to compute somatic copy number aberrations. This, in turn, was used to infer the evolutionary history of these patients. FINDINGS: The data show different metastatic seeding patterns, with both an early and late divergence of the metastatic lineage observed in ILC. Additionally, cascading dissemination from a metastatic precursor was a dominant rule. Alterations in key cancer driver genes, such as TP53 or CCND1, were acquired early while additional aberrations were present only in the metastatic branch. In about 30% of the patients, the metastatic lineage harboured less aberrations than the primary tumour suggesting a period of tumour dormancy or prolonged adaptation at the distant site. This phenomenon was mostly observed in tumours from de novo metastatic patients. INTERPRETATION: Our results provide insights into ILC evolution and offer potential paths for optimised ILC care. FUNDING: This work has received financial support from Les Amis de l'Institut Bordet, MEDIC, the Breast Cancer Research Foundation (BCRF) and the Belgian Fonds National de la Recherche Scientifique (F.R.S-FNRS).