The Impact of COVID-19 on Treatment Practices for Patients With Early Breast Cancer: A Cross-Sectional Study From a Large Cancer Center in Italy.

INTRODUCTION: The Coronavirus Disease 2019 (COVID-19) has disrupted health services worldwide. The evidence on the impact of the pandemic on cancer care provision, however, is conflicting. We aimed to audit the management of patients diagnosed with early breast cancer (EBC) during the pandemic in a large, tertiary-level cancer center in Italy. METHODS: We conducted a cross-sectional study to track the route to first treatment for patients diagnosed with EBC during 2019, 2020, and 2021. We abstracted data for all consecutive patients referred to the Veneto Institute of Oncology (Padua, Italy). We defined as point of contact (POC) the date of the first consultation with a breast cancer specialist of the breast unit. First treatment was defined as either upfront surgery or neoadjuvant chemotherapy (NACT). RESULTS: We reviewed medical records for 878 patients for whom an MDT report during 2019-2021 (April through June) was available. Of these, 431 (49%) were eligible. The proportion of screen-detected tumors was larger in 2019 and 2021 than in 2020 (59%). Conversely, the proportion of screen-detected tumors was offset by the proportion of palpable tumors in 2020 (P = .004). Distribution of tumor and nodal stage was unchanged over time, but in situ tumors were slightly fewer in 2020 than in 2019 or 2021. The adjusted odds ratio for treatment delay (45 days or more) was 0.87 for 2020 versus 2019 (95% CI, 0.5-1.53) and 0.9 for 2021 versus 2019 (95% CI, 0.52-1.55). CONCLUSIONS: There was no evidence for major changes in the management of patients with EBC during 2019-2021 and no treatment delays were observed. Our findings suggest that more women presented with palpable nodules at diagnosis, but the stage distribution did not change over time. Validation on a larger cohort of patients is warranted to robustly assess the impact of the COVID-19 pandemic on treatment practices for patients with EBC.

A Prognostic Model Based on Residual Cancer Burden and Tumor-Infiltrating Lymphocytes on Residual Disease after Neoadjuvant Therapy in HER2+ Breast Cancer.

PURPOSE: We aim to evaluate the prognostic significance of tumor-infiltrating lymphocyte on residual disease (RD-TIL) in HER2+ patients with breast cancer who failed to achieve pathologic complete response (pCR) after anti-HER2+ chemotherapy (CT)-based neoadjuvant treatment (NAT). We assessed the feasibility of combining the prognostic information provided by residual cancer burden (RCB) and RD-TILs into a composite score (RCB+TIL). EXPERIMENTAL DESIGN: HER2+ patients with breast cancer treated with CT+anti-HER2-based NAT at three institutions were retrospectively included. RCB and TIL levels were evaluated on hematoxylin and eosin-stained slides from surgical samples according to available recommendations. Overall survival (OS) was used as an outcome measure. RESULTS: A total of 295 patients were included, of whom 195 had RD. RCB was significantly associated with OS. Higher RD-TILs were significantly associated with poorer OS as compared with lower RD-TILs (15% cutoff). In multivariate analysis, both RCB and RD-TIL maintained their independent prognostic value. A combined score, RCB+TIL, was calculated from the estimated coefficient of RD-TILs and the RCB index in a bivariate logistic model for OS. The RCB+TIL score was significantly associated with OS. The C-index for OS of the RCB+TIL score was numerically higher than that of RCB and significantly higher than that of RD-TILs. CONCLUSIONS: We have reported an independent prognostic impact of RD-TILs after anti-HER2+CT NAT, which might underlie an imbalance of the RD microenvironment towards immunosuppressive features. We provided a new composite prognostic score based on RCB+TIL, which was significantly associated with OS and proved to be more informative than the isolated evaluation of RCB and RD-TILs.

PI3K/PTEN/mTOR pathway dynamic tracking and prognostic value in HR+/HER2- BC patients with residual disease after neoadjuvant chemotherapy: a cohort study.

AIMS: Hormone receptor-positive (HR)+/HER2- breast cancer (BC) is highly heterogeneous, with PI3K/PTEN/mTOR pathway alterations emerging as possible players within this complexity. We longitudinally tracked PI3K/PTEN/mTOR pathway dynamics from baseline biopsy to residual disease (RD)-and to metastases in case of relapse-in HR+/HER2- BC patients receiving neoadjuvant chemotherapy (NACT). METHODS: HR+/HER2- BC patients with RD after NACT were identified. We assessed PIK3CA mutational, Pten-loss and phosphorylation levels of mTOR and its substrates (p70S6K and 4EBP1) on baseline biopsies and matched RD samples; in case of disease relapse, we also assessed PIK3CA mutational status on metastatic samples. Recurrence-free survival (RFS) was adopted as endpoint. RESULTS: 92 patient were included. The conversion rate of PIK3CA mutational status was 12.8%; 1 patient acquired PIK3CA mutation at relapse; the rate of Pten conversion was 33.3%; mTOR phosphorylation levels significantly increased from baseline biopsy to RD, while its substrates significantly decreased. Baseline phosphorylated-mTOR significantly predicted poorer RFS in patients with PIK3CA wild-type status; baseline phosphorylated-70S6K was positively associated with RFS. CONCLUSIONS: We observed that PI3K/PTEN/mTOR pathway is highly dynamic under NACT exposure and the assessment of PIK3CA mutations may capture only a small fraction of such complexity. In this context, mTOR activation trough alternative pathways with respect to PIK3CA signalling may have a crucial role in shaping the molecular landscape of HR+/HER2- BC with RD after NACT. It is imperative to further elucidate the role of PIK3CA and mTOR-dependent pathways in shaping chemoresistance and endocrine resistance in high-risk HR+/HER2- early/locally advanced BC patients.

Characterization of Gut Microbiome Composition in Patients with Triple-Negative Breast Cancer Treated with Neoadjuvant Chemotherapy.

INTRODUCTION: Patients with triple-negative breast cancer (TNBC) achieving a pathological complete response (pCR) after neoadjuvant chemotherapy have a better event-free survival. The role of gut microbiome in early TNBC is underexplored. METHODS: Microbiome was analyzed by 16SrRNA sequencing. RESULTS: Twenty-five patients with TNBC treated with neoadjuvant anthracycline/taxane-based chemotherapy were included. Fifty-six percent achieved a pCR. Fecal samples were collected before (t0), at 1 (t1), and 8 weeks (t2) from chemotherapy. Overall, 68/75 samples (90.7%) were suitable for microbiome analysis. At t0, pCR group showed a significantly higher α-diversity as compared with no-pCR, (P = .049). The PERMANOVA test on ß-diversity highlighted a significant difference in terms of BMI (P = 0.039). Among patients with available matched samples at t0 and t1, no significant variation in microbiome composition was reported over time. CONCLUSIONS: Fecal microbiome analysis in early TNBC is feasible and deserves further investigation in order to unravel its complex correlation with immunity and cancer.

Incorporating weekly carboplatin in anthracycline and paclitaxel-containing neoadjuvant chemotherapy for triple-negative breast cancer: propensity-score matching analysis and TIL evaluation.

BACKGROUND: The generation of data capturing the risk-benefit ratio of incorporating carboplatin (Cb) to neoadjuvant chemotherapy (NACT) for triple-negative breast cancer (TNBC) in a clinical practice setting is urgently needed. Tumour-infiltrating lymphocytes (TILs) have an established role in TNBC receiving NACT, however, the role of TIL dynamics under NACT exposure in patients receiving the current standard of care is largely uncharted. METHODS: Consecutive TNBC patients receiving anthracycline-taxane [A-T] +/- Cb NACT at three Institutions were enrolled. Stromal-TILs were evaluated on pre-NACT and residual disease (RD) specimens. In the clinical cohort, propensity-score-matching was used to control selection bias. RESULTS: In total, 247 patients were included (A-T = 40.5%, A-TCb = 59.5%). After propensity-score-matching, pCR was significantly higher for A-TCb vs A-T (51.9% vs 34.2%, multivariate: OR = 2.40, P = 0.01). No differences in grade ≥3 haematological toxicities were observed. TILs increased from baseline to RD in the overall population and across A-T/A-TCb subgroups. TIL increase from baseline to RD was positively and independently associated with distant disease-free survival (multivariate: HR = 0.43, P = 0.05). CONCLUSIONS: We confirmed in a clinical practice setting of TNBC patients receiving A-T NACT that the incorporation of weekly Cb significantly improved pCR. In addition, A-T +/- Cb enhanced immune infiltration from baseline to RD. Finally, we reported a positive independent prognostic role of TIL increase after NACT exposure.

Morphological and molecular characterization of colorectal sessile serrated lesions with dysplasia.

In sessile serrated lesions (SSLs) with adenomatous dysplasia, the dysplastic component and the serrated component without dysplasia should be considered as part of the same lesion, classified as SSL with dysplasia. However, some of these lesions may actually represent collisions between a serrated polyp and a conventional adenoma. Further supporting the "collision theory", conventional adenomatous dysplasia may be found in association with hyperplastic polyps (HPs). In order to determine the molecular and biological landscape of conventional type dysplasia in serrated lesions, we collected 17 cases of colorectal serrated lesions with adenomatous dysplasia, classifying them as SSL with dysplasia (n = 10) or as mixed lesions comprising a HP component and a conventional adenomatous component (n = 7). We characterized the dysplastic and the non-dysplastic component of each lesion, after microdissection, through the targeted mutational analysis of 11 commonly altered genes in colorectal cancer (AKT1, APC, BRAF, CTNNB1, KIT, KRAS, NRAS, PDGFRA, PIK3CA, PTEN and TP53). We also characterized MMR and p53 status by immunohistochemistry. Overall, 14/17 (82.4 %) cases harbored a mutation in at least one of the two components. The most altered genes were BRAF in 10/17 (58.8 %) cases, APC in 2/17 (11.8 %) and TP53 in 4/17 (23.5 %). Among the SSL with dysplasia, the mutational profile was concordant between the two components in 7/10 (70 %) cases, while among the mixed lesions, the mutational profile was concordant in 1/7 (14.3 %). In all but two cases of SSL with dysplasia, MMR status was concordant between the two components of the serrated lesions. Our findings suggest that adenomatous dysplasia may develop in SSL as part of the serrated lesion, even if some SSL with dysplasia may actually be collision lesions. On the other hand, the polyps that are morphologically classifiable as mixed lesions composed of a HP and a conventional adenomatous component are more likely to be collision lesions.

HER2-low-positive breast cancer: evolution from primary tumor to residual disease after neoadjuvant treatment.

Approximately a half of breast tumors classified as HER2-negative exhibit HER2-low-positive expression. We recently described a high instability of HER2-low-positive expression from primary breast cancer (BC) to relapse. Previous studies reporting discordance in HER2 status between baseline biopsy and residual disease (RD) in patients undergoing neoadjuvant treatment did not include the HER2-low-positive category. The aim of this study is to track the evolution of HER2-low-positive expression from primary BC to RD after neoadjuvant treatment. Patients undergoing neoadjuvant treatment with available baseline tumor tissue and matched samples of RD (in case of no pCR) were included. HER2-negative cases were sub-classified as HER2-0 or HER2-low-positive (IHC 1+ or 2+ and ISH negative). Four-hundred forty-six patients were included. Primary BC phenotype was: HR-positive/HER2-negative 23.5%, triple-negative (TN) 35%, HER2-positive 41.5%. HER2-low-positive cases were 55.6% of the HER2-negative cohort and were significantly enriched in the HR-positive/HER2-negative vs. TN subgroup (68.6% vs. 46.8%, p = 0.001 χ2 test). In all, 35.3% of non-pCR patients (n = 291) had a HER2-low-positive expression on RD. The overall rate of HER2 expression discordance was 26.4%, mostly driven by HER2-negative cases converting either from (14.8%) or to (8.9%) HER2-low-positive phenotype. Among HR-positive/HER2-negative patients with HER2-low-positive expression on RD, 32.0% and 57.1% had an estimated high risk of relapse according to the residual proliferative cancer burden and CPS-EG score, respectively. In conclusion, HER2-low-positive expression showed high instability from primary BC to RD after neoadjuvant treatment. HER2-low-positive expression on RD may guide personalized adjuvant treatment for high-risk patients in the context of clinical trials with novel anti-HER2 antibody-drug conjugates.

Gastric metastases of breast cancer: Histopathological and molecular characterization of a single Institution case series.

The metastatic spread of breast carcinoma to the stomach is a rare event and often represents a diagnostic challenge. In the present study, 23 cases of gastric metastases from breast cancer were retrospectively identified dating back until 2007. Primitive histotype, localization, gross appearance, microscopic architecture were analyzed. Cytokeratins 7 and 20, sex hormones, HER2 and Ki67 expression was evaluated. According to the results, the series was characterized by an enrichment of lobular primitive histotype (43.7%). In most cases gastric metastases were described as parietal nodules, polypoid masses or ulcerated lesions, mainly involving the antro-angular region. In a relatively high rate (10.5%) of cases, endoscopic examinations resulted negative for macroscopic lesions. More than half of the cases (52.2%) microscopically resembled primitive poorly cohesive gastric cancer. Because gross and histological findings can be deceiving, immunohistochemistry may be essential for the diagnosis of gastric metastases from breast cancer. Accordingly with the results of our analysis and literature review, an immunohistochemical panel composed of cytokeratins 7 and 20, Estrogen and Progesteron Receptors would drastically improve diagnostic accuracy. Interaction among the clinician, endoscopist and the pathologist is also essential to provide the patient the best therapeutic option.

Neoadjuvant Chemotherapy and Immunotherapy in Luminal B-like Breast Cancer: Results of the Phase II GIADA Trial.

PURPOSE: The role of immunotherapy in hormone receptor (HR)-positive, HER2-negative breast cancer is underexplored. PATIENTS AND METHODS: The neoadjuvant phase II GIADA trial (NCT04659551, EUDRACT 2016-004665-10) enrolled stage II-IIIA premenopausal patients with Luminal B (LumB)-like breast cancer (HR-positive/HER2-negative, Ki67 ≥ 20%, and/or histologic grade 3). Patients received: three 21-day cycles of epirubicin/cyclophosphamide followed by eight 14-day cycles of nivolumab, triptorelin started concomitantly to chemotherapy, and exemestane started concomitantly to nivolumab. Primary endpoint was pathologic complete response (pCR; ypT0/is, ypN0). RESULTS: A pCR was achieved by 7/43 patients [16.3%; 95% confidence interval (CI), 7.4-34.9]; the rate of residual cancer burden class 0-I was 25.6%. pCR rate was significantly higher for patients with PAM50 Basal breast cancer (4/8, 50%) as compared with other subtypes (LumA 9.1%; LumB 8.3%; P = 0.017). Tumor-infiltrating lymphocytes (TIL), immune-related gene-expression signatures, and specific immune cell subpopulations by multiplex immunofluorescence were significantly associated with pCR. A combined score of Basal subtype and TILs had an AUC of 0.95 (95% CI, 0.89-1.00) for pCR prediction. According to multiplex immunofluorescence, a switch to a more immune-activated tumor microenvironment occurred following exposure to anthracyclines. Most common grade ≥3 treatment-related adverse events (AE) during nivolumab were γ-glutamyltransferase (16.7%), alanine aminotransferase (16.7%), and aspartate aminotransferase (9.5%) increase. Most common immune-related AEs were endocrinopathies (all grades 1-2; including adrenal insufficiency, n = 1). CONCLUSIONS: Luminal B-like breast cancers with a Basal molecular subtype and/or a state of immune activation may respond to sequential anthracyclines and anti-PD-1. Our data generate hypotheses that, if validated, could guide immunotherapy development in this context.

Evolution of HER2-low expression from primary to recurrent breast cancer.

About a half of HER2-negative breast cancer (BC) show HER2-low expression that can be targeted by new antibody-drug conjugates. The main aim of this study is to describe the evolution of HER2 expression from primary BC to relapse by including HER2-low category in both primary and recurrent BC samples. Patients with matched primary and relapse BC samples were included. HER2 was evaluated according to ASCO/CAP recommendations in place at the time of diagnosis. A cutoff of >10% cells staining for HER2-positivity was applied. HER2-negative cases were sub-classified as HER2-low (IHC = 1 + /2+ and ISH not amplified), or HER2-0 (IHC-0). 547 patients were included. The proportion of HER2-low cases was 34.2% on the primary tumor and 37.3% on the relapse samples. Among HER2-negative cases, HER2-low status was more frequent in HR-positive vs triple-negative tumors (47.3% vs 35.4% on primary tumor samples, 53.8% vs 36.2% on relapse samples). The overall rate of HER2 discordance was 38.0%, mostly represented by HER2-0 switching to HER2-low (15%) and HER2-low switching to HER2-0 (14%). Among patients with a primary HER2-negative tumor, the rate of HER2 discordance was higher in HR-positive/HER2-negative vs triple-negative cases (45.5% vs 36.7% p = 0.170). This difference was mostly driven by cases switching from HER2-0 to HER2-low. HER2-low expression is highly unstable during disease evolution. Relapse biopsy in case of a primary HER2-0 tumor may open new therapeutic opportunities in a relevant proportion of patients.

Impact of estrogen receptor levels on outcome in non-metastatic triple negative breast cancer patients treated with neoadjuvant/adjuvant chemotherapy.

Although 1% is the recommended cut-off to define estrogen receptor (ER) positivity, a 10% cut-off is often used in clinical practice for therapeutic purposes. We here evaluate clinical outcomes according to ER levels in a monoinstitutional cohort of non-metastatic triple-negative breast cancer (BC) patients undergoing (neo)adjuvant chemotherapy. Clinicopathological data of 406 patients with ER < 10% HER2-negative BC treated with (neo)adjuvant chemotherapy between 01/2000 and 04/2019 were collected. Patients were categorized in ER-negative (ER < 1%; N = 364) and ER-low positive (1-9%, N = 42). At a median follow-up of 54 months, 88 patients had relapsed and 64 died. No significant difference was observed in invasive relapse-free survival (iRFS) and overall survival (OS) according to ER expression levels, both at univariate and multivariate analysis (5-years iRFS 74.0% versus 73.1% for ER-negative and ER-low positive BC, respectively, p = 0.6; 5-years OS 82.3% versus 76.7% for ER-negative and ER-low positive BC, respectively, p = 0.8). Among the 165 patients that received neoadjuvant chemotherapy, pathological complete response rate was similar in the two cohorts (38% in ER-negative, 44% in ER-low positive, p = 0.498). In conclusion, primary BC with ER1-9% shows similar clinical behavior to ER 1% BC. Our results suggest the use of a 10% cut-off, rather than <1%, to define triple-negative BC.

The histomorphological and molecular landscape of colorectal adenomas and serrated lesions.

The 2019 WHO classification of digestive system tumors significantly reformed the classificatory definition of serrated lesions of the colorectal mucosa and added new essential diagnostic criteria for both conventional adenomas and hereditary gastrointestinal polyposis syndromes. Histopathological examination of colorectal adenocarcinoma precursors lesions represents an important segment of daily clinical practice in a pathology department and is essential for the implementation of current colorectal adenocarcinoma secondary prevention strategies. This overview will focus on a schematic histopathological and molecular classification of precursor lesions arising within colorectal mucosa.

Preoperative non-palpable breast lesion localization, innovative techniques and clinical outcomes in surgical practice: A systematic review and meta-analysis.

Pre-operative localization of non-palpable breast lesions with non-wired non-ionizing (NWNI) techniques may improve clinical outcomes as reoperation rate, cosmetic outcome and contribute to organizational aspects improvement in breast-conserving surgery (BCS). However only limited literature is available and clinical studies involving these forefront devices are often small and non-randomized. Furthermore, there is a lack of consensus on free margins and cosmetic outcomes definitions. The objective of the present meta-analysis was to determine the crude clinical outcomes reported for the NWNI techniques on BCS. A literature search was performed of PubMed, Embase and Scopus databases up to February 2021 in order to select all prospective or retrospective clinical trials on pre-operative breast lesion localization done with NWNI devices. All studies were assessed following the PRISMA recommendations. Continuous outcomes were described in averages corrected for sample size, while binomial outcomes were described using the weighted average proportion. Twenty-seven studies with a total of 2103 procedures were identified. The technique is consolidated, showing for both reflectors' positioning and localization nearly the 100% rate of success. The re-excision and clear margins rates were 14% (95% CI, 11-17%) and 87% (80-92%), respectively. Overall, positive margins rates were 12% (8-17%). In studies that compared NWNI and wire localization techniques, positive margin rate is lower for the first techniques (12%, 6-22% vs 17%, 12-23%) and re-excision rate is slightly higher using the latter (13%, 9-19% vs 16%, 13-18%). Pre-operative NWNI techniques are effective in the localization of non-palpable breast lesions and are promising in obtaining clear (or negative) margins minimizing the need for re-excision and improving the cosmetic outcomes. Randomized trials are needed to confirm these findings.

ESR1 Gene Mutation in Hormone Receptor-Positive HER2-Negative Metastatic Breast Cancer Patients: Concordance Between Tumor Tissue and Circulating Tumor DNA Analysis.

Endocrine therapy represents the cornerstone of treatment in hormone receptor-positive (HR+), HER2-negative metastatic breast cancer (mBC). The natural course of this disease is marked by endocrine resistance, mainly due to Estrogen Receptor 1 (ESR1) acquired mutations. The aim of this study is to evaluate the concordance between ESR1 status in metastatic tumor specimens and matched circulating tumor DNA (ctDNA). Forty-three patients with HR+, HER2-negative mBC underwent both a metastatic tumor biopsy and a liquid biopsy at the time of disease progression. DNA extracted from formalin fixed paraffin embedded (FFPE) tumor specimens and ctDNA from matched plasma were analyzed by droplet digital (dd)PCR for the main ESR1 mutations (Y537S, Y537C, Y537N, D538G, E380Q). We observed a total mutation rate of 21%. We found six mutations on tissue biopsy: Y537S (1), D538G (2), Y537N (1), E380Q (2). Three patients with no mutations in tumor tissue had mutations detected in ctDNA. The total concordance rate between ESR1 status on tumor tissue and plasma was 91%. Our results confirm the potential role of liquid biopsy as a non-invasive alternative to tissue biopsy for ESR1 mutation assessment in mBC patients.

The Tumor Microenvironment of Primitive and Metastatic Breast Cancer: Implications for Novel Therapeutic Strategies.

Breast cancer evolves thanks to a dense and close interaction with the surrounding tumor microenvironment (TME). Fibroblasts, leukocytes, blood and lymphatic endothelial cells and extracellular matrix are the constituents of this entity, and they synergistically play a pivotal role in all of the stages of breast cancer development, from its onset to its metastatic spread. Moreover, it has been widely demonstrated that variations to the TME can correspond to prognosis variations. Breast cancer not only modulates the transformation of the environment within the mammary gland, but the same process is observed in metastases as well. In this minireview, we describe the features of TME within the primitive breast cancer, throughout its evolution and spread into the main metastatic sites.

Prognostic factors in phyllodes tumours of the breast: retrospective study on 166 consecutive cases.

BACKGROUND: Phyllodes tumours (PTs) are rare fibroepithelial tumours accounting for <1% of all breast tumours. We assessed clinicopathological features and their prognostic effect in a single-institution patients' cohort. METHODS: Patients diagnosed with PT between 2001 and 2018 at our institution were identified. Clinical, surgical and pathological features were collected. Phyllodes-related relapse was defined as locoregional or distant recurrence (contralateral excluded), whichever first. RESULTS: A total of 166 patients were included: 115 with benign, 30 with borderline and 21 with malignant PTs. Features associated with malignant PT were younger age, larger T size, higher mitotic count, marked cytological atypia, stromal overgrowth, stromal hypercellularity, necrosis and heterologous differentiation (all p<0.01). The majority of patients with malignant PT underwent mastectomy (63.2% vs 3% of benign/borderline, p<0.001) and had negative surgical margins (83.3%). 4-year cumulative phyllodes-related relapse incidence was 7% for benign/borderline PT and 21.3% for malignant PT (p=0.107). In the entire cohort, marked cellular atypia and heterologous differentiation were associated with worse phyllodes-related relapse-free survival (HR 14.10, p=0.036 for marked vs mild atypia; HR 4.21, p=0.031 for heterologous differentiation present vs absent). For patients with benign PT, larger tumour size was associated with worse phyllodes-related relapse-free survival (HR 9.67, p=0.013 for T>5 cm vs T≤2 cm). Higher tumour-infiltrating lymphocytes (TILs) were associated with borderline and malignant PT (p=0.023); TILs were not associated with phyllodes-related relapse-free survival (HR 0.58, p=0.361 for TILs>2% vs≤2%). Overall, four patients died because of PT: three patients with malignant and one with borderline PT. CONCLUSIONS: Patients with malignant PT had increased rates of phyllodes-related relapse and phyllodes-related death. Cellular atypia and heterologous differentiation were poor prognostic factors in the entire cohort; large tumour size was associated with an increased risk of phyllodes-related relapse in benign PT.

Validation of Residual Proliferative Cancer Burden as a Predictor of Long-Term Outcome Following Neoadjuvant Chemotherapy in Patients with Hormone Receptor-Positive/Human Epidermal Growth Receptor 2-Negative Breast Cancer.

BACKGROUND: The integration of residual cancer burden (RCB) and post-treatment Ki67 as residual proliferative cancer burden (RPCB) has been proposed as a stronger predictor of long-term outcome in unselected patients with breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT), as compared with RCB. However, no specific analysis in hormone-receptor-positive (HR+) human epidermal growth receptor 2-negative (HER2-) BC is available so far. MATERIALS AND METHODS: A cohort of 130 patients with HR+/HER2- BC who underwent NACT between 2000 and 2014 was included. Archival surgical specimens were evaluated for RCB. RPCB was calculated by combining RCB and Ki67 as previously described. Patients were categorized in four RCB and RPCB categories (pathological complete response and tertiles). Disease-free survival (DFS) and overall survival (OS) estimates were determined by Kaplan-Meier analysis and compared using the log-rank test. Overall change of χ2 and c-indexes were used to compare the performance of the prognostic models. RESULTS: RPCB was calculated for 85 patients. After a median follow up of 8.5 years, RCB was associated with OS (p = .048) but not with DFS (p = .152); RPCB was instead significantly associated with both DFS and OS (p = .034 and p < .001, respectively). In terms of OS, RPCB provided a significant amount of prognostic information beyond RCB (∆χ2 5.73, p < .001). In addition, c-index for OS prediction was significantly higher for RPCB as compared with RCB (0.79 vs. 0.61, p = .03). CONCLUSION: This is the first study evaluating RPCB in patients with HR+/HER2- BC treated with NACT. In this independent cohort, RPCB was a strong predictor of DFS and OS. The better performance of RPCB versus RCB was in part due to the ability of RPCB to discriminate a subgroup of patients with a particularly worse prognosis after NACT, who may be candidates for clinical trials evaluating novel adjuvant strategies. IMPLICATIONS FOR PRACTICE: The present work validated residual proliferative cancer burden (RPCB) as a strong predictor of long-term outcome in patients with hormone receptor-positive human epidermal growth receptor 2-negative (HR+/HER2-) breast cancer (BC) treated with neoadjuvant chemotherapy. In addition, results from the present study suggest RPCB as a promising tool to identify patients with HR+/HER2- BC who might potentially benefit from the inclusion in clinical trials evaluating novel or escalated postneoadjuvant treatment strategies because it allowed to discriminate a subgroup of patients with particularly poor prognosis despite having received subsequent endocrine therapy in the adjuvant setting.

Integration of tumour infiltrating lymphocytes, programmed cell-death ligand-1, CD8 and FOXP3 in prognostic models for triple-negative breast cancer: Analysis of 244 stage I-III patients treated with standard therapy.

BACKGROUND: Tumour infiltrating lymphocytes (TILs) are an established prognostic biomarker for triple-negative breast cancer (TNBC). We evaluated the role of programmed cell-death ligand-1 (PD-L1), CD8 and FOXP3 expression in refining a prognostic model for non-metastatic TNBC beyond classic factors and TILs. METHODS: Primary tumour samples from 244 early patients with TNBC, all treated with surgery and chemotherapy, were collected. Stromal TILs were evaluated on haematoxylin-eosin slides according to guidelines. PD-L1, CD8 and FOXP3 were assessed by immunohistochemistry and evaluated by digital pathology. RESULTS: TILs, PD-L1, CD8 and FOXP3 were positively correlated with each other (P < 0.001). TILs were confirmed as an independent prognostic factor. When PD-L1, CD8 and FOXP3 were added to multivariable models including classic factors (age, stage, histologic grade) and TILs, PD-L1 provided the largest amount of additional prognostic information: likelihood ratio χ2 4.60, P = 0.032 (in a model including classic factors and TILs 10% increments) and likelihood ratio χ2 6.50, P = 0.011 (in a model including classic factors and TILs >30% versus <30%). In the subset of patients treated with neoadjuvant chemotherapy, FOXP3 provided further prognostic information beyond classic factors, TILs and pathological complete response (pCR) (likelihood ratio χ2 5.01, P = 0.025). For patients who did not achieve a pCR, the expression of CD8 and PD-L1 was significantly increased from baseline to residual disease. CONCLUSIONS: Beyond clinicopathological factors and TILs, other immune biomarkers may add prognostic information for early TNBC. The increased PD-L1 expression on residual disease after neoadjuvant chemotherapy strengthens the rationale of testing immune checkpoint inhibitors in the post-neoadjuvant setting.