Invasive lobular breast cancer: Focus on prevention, genetics, diagnosis, and treatment.

Invasive lobular cancer (ILC) is the most common of the breast cancer special types, accounting for up to 15% of all breast malignancies. The distinctive biological features of ILC include the loss of the cell adhesion molecule E-cadherin, which drives the tumor's peculiar discohesive growth pattern, with cells arranged in single file and dispersed throughout the stroma. Typically, such tumors originate in the lobules, are more commonly bilateral compared to invasive ductal cancer (IDC) and require a more accurate diagnostic examination through imaging. They are luminal in molecular subtype, and exhibit estrogen and progesterone receptor positivity and HER2 negativity, thus presenting a more unpredictable response to neoadjuvant therapies. There has been a significant increase in research focused on this distinctive breast cancer subtype, including studies on its pathology, its clinical and surgical management, and the high-resolution definition of its genomic profile, as well as the development of new therapeutic perspectives. This review will summarize the heterogeneous pattern of this unique disease, focusing on challenges in its comprehensive clinical management and on future insights and research objectives.

Effect of age on safety and efficacy of novel cancer drugs investigated in early-phase clinical trials.

BACKGROUND: Elderly patients are underrepresented in clinical trials, particularly in early-phase studies. Our study assessed the safety and efficacy of novel anti-cancer treatments investigated in early-phase clinical trials, comparing outcomes between younger and elderly patients. METHODS: This retrospective study analyzed data from patients enrolled in phase I/II trials at our center between January 2014 and April 2021. We evaluated clinicopathologic characteristics, toxicity, and clinical efficacy, categorizing patients into younger (≤ 65 years) and elderly (> 65 years) groups. RESULTS: 419 patients were included with a median age of 56 years. Among these, 107 (26 %) were older than 65 years. Predominant cancers included breast (48 %), lung (10 %), and melanoma (5 %). Patients were treated in 64 trials, predominantly receiving immunotherapy-based (47 %) or targeted therapy-based (45 %) treatment. Elderly presented with poorer ECOG performance status (P = 0.001) and had fewer prior therapy lines (P = 0.01) than younger patients. Grade ≥ 3 adverse events (AEs) were similar across age groups (31 % younger vs 33 % elderly; P = 0.7), including in combination therapy scenarios. However, elderly patients experienced more AEs with antibody-drug conjugates compared to younger counterparts (56 % vs 14 %, P = 0.036) and were more likely to discontinue treatment due to toxicity (15 % vs 7 %; P = 0.011). No significant age-related differences in response rates and survival outcomes were observed across treatment modalities, except for immunotherapy-based regimens for which elderly patients exhibited higher response rates, disease control rates, and prolonged progression-free survival. CONCLUSIONS: Our findings suggest that elderly exhibit comparable safety and efficacy outcomes to younger patients in early-phase clinical trials for new cancer drugs. This underscores the importance of including elderly patients in phase I/II trials to ensure the generalizability of study results and mitigate age-related disparities in cancer treatment access.

Baseline Tumor Size as Prognostic Index in Patients With Advanced Solid Tumors Receiving Experimental Targeted Agents.

BACKGROUND: Baseline tumor size (BTS) has been associated with outcomes in patients with cancer treated with immunotherapy. However, the prognostic impact of BTS on patients receiving targeted therapies (TTs) remains undetermined. METHODS: We reviewed data of patients with advanced solid tumors consecutively treated within early-phase clinical trials at our institution from 01/2014 to 04/2021. Treatments were categorized as immunotherapy-based or TT-based (biomarker-matched or not). BTS was calculated as the sum of RECIST1.1 baseline target lesions. RESULTS: A total of 444 patients were eligible; the median BTS was 69 mm (IQR 40-100). OS was significantly longer for patients with BTS lower versus higher than the median (16.6 vs. 8.2 months, P < .001), including among those receiving immunotherapy (12 vs. 7.5 months, P = .005). Among patients receiving TT, lower BTS was associated with longer PFS (4.7 vs. 3.1 months, P = .002) and OS (20.5 vs. 9.9 months, P < .001) as compared to high BTS. However, such association was only significant among patients receiving biomarker-matched TT, with longer PFS (6.2 vs. 3.3 months, P < .001) and OS (21.2 vs. 6.7 months, P < .001) in the low-BTS subgroup, despite a similar ORR (28% vs. 22%, P = .57). BTS was not prognostic among patients receiving unmatched TT, with similar PFS (3.7 vs. 4.4 months, P = .30), OS (19.3 vs. 11.8 months, P = .20), and ORR (33% vs. 28%, P = .78) in the 2 BTS groups. Multivariate analysis confirmed that BTS was independently associated with PFS (P = .03) and OS (P < .001) but not with ORR (P = .11). CONCLUSIONS: Higher BTS is associated with worse survival outcomes among patients receiving biomarker-matched, but not biomarker-unmatched TT.

Cardiotoxicity of Agents Used in Patients With Breast Cancer.

Cancer and cardiovascular diseases are the two major causes of mortality, morbidity, and disability worldwide. The improvement in effective therapeutic options for the management of breast cancer (BC) has led to an increased number of BC survivors, who can experience long-term toxicities from cancer treatments. Adverse events including cardiovascular toxicities must be considered in light of effectiveness of recently approved drugs for BC treatment, including elacestrant, tucatinib, neratinib, olaparib, the immune checkpoint inhibitors, trastuzumab deruxtecan, or sacituzumab govitecan. Many cancer drugs affect the cardiovascular system with a range of clinical manifestations. Prompt diagnosis and treatment as well as a multidisciplinary approach involving a cardio-oncologist is optimal for management of these cardiovascular events.

Association of PIK3CA Mutation With Pathologic Complete Response and Outcome by Hormone Receptor Status and Intrinsic Subtype in Early-Stage ERBB2/HER2-Positive Breast Cancer.

Importance: PIK3CA mutations may be associated with outcomes of patients with ERBB2/HER2-positive early breast cancer (EBC). Objectives: To assess if PIK3CA mutations among patients with ERBB2/HER2-positive EBC are associated with treatment response and outcome, and if these associations vary by hormone receptor (HR) status or intrinsic molecular subtype (IMS). Design, Setting, and Participants: This cohort study derived data on 184 patients from the phase 3 neoadjuvant Cancer and Leukemia Group B (CALGB) 40601 trial that enrolled patients with ERBB2/HER2-positive EBC in North America between January 1, 2008, and December 31, 2012. Participants received neoadjuvant paclitaxel with trastuzumab, lapatinib, or both. Statistical analysis was performed from March 23, 2022, to March 9, 2023. Exposures: Gene expression profiling by RNA sequencing with Prediction Analysis of Microarray 50-determined IMS and PIK3CA mutations from whole-exome sequencing were obtained from pretreatment biopsies from 184 of 305 trial participants. Main Outcomes and Measures: The primary end point was pathologic complete response (pCR) and the secondary end point of event-free survival (EFS). The association of PIK3CA mutations with pCR and EFS by HR status and IMS was estimated using logistic and Cox proportional hazards regression models. Results: All 184 participants were women, with a median age of 49 years (range 24-75 years). A total of 121 participants (66%) had clinical stage II tumors; 32 (17%) had PIK3CA mutations, most frequently H1047R (38% [12 of 32]) and E545K (22% [7 of 32]). PIK3CA mutations were present in 20 of 102 cases of HR-positive EBC (20%) and 12 of 82 cases HR-negative EBC (15%) and varied by IMS (luminal B, 9 of 25 [36%]; luminal A, 2 of 21 [10%]; and ERBB2/HER2-enriched tumors, 19 of 102 [19%]). Pathologic complete response rates were lower in PIK3CA mutated than PIK3CA wild type in the overall population (34% [11 of 32] vs 49% [74 of 152]; P = .14) and were significantly different among those receiving trastuzumab (30% [7 of 23] vs 54% [63 of 117]; P = .045). At a median follow-up of 9 years, PIK3CA mutations were significantly associated with worse EFS in the overall cohort (hazard ratio, 2.58 [95% CI, 1.24-5.35]; P = .01), which persisted in a multivariable model including pCR, HR status, stage, and IMS (hazard ratio, 2.52 [95% CI, 1.16-5.47]; P = .02). The negative association of PIK3CA mutation was significant in HR-positive (hazard ratio, 3.60 [95% CI, 1.45-8.96]; P = .006) and luminal subtypes (hazard ratio, 4.84 [95% CI, 1.08-21.70]; P = .04), but not in nonluminal and HR-negative tumors. Conclusions and Relevance: In ERBB2/HER2-positive EBC, PIK3CA mutations were associated with lower pCR rates and independently associated with worse long-term EFS. These findings appear to be associated with PIK3CA mutations in HR-positive and luminal EBC.

Peripheral blood lymphocytes predict clinical outcomes in hormone receptor-positive HER2-negative advanced breast cancer patients treated with CDK4/6 inhibitors.

Background: Cyclin-Dependent Kinase 4/6 inhibitors (CDK4/6i) combined with Endocrine Therapy (ET) are the standard treatment for patients with Hormone Receptor-positive/HER2-negative advanced breast cancer (HR+/HER2- aBC). Objectives: While CDK4/6i are known to reduce several peripheral blood cells, such as neutrophils, lymphocytes and platelets, the impact of these modulations on clinical outcomes is unknown. Design: A multicenter, retrospective-prospective Italian study. Methods: We investigated the association between baseline peripheral blood cells, or their early modifications (i.e. 2 weeks after treatment initiation), and the progression-free survival (PFS) of HR+/HER2- aBC patients treated with ETs plus CDK4/6i. Random Forest models were used to select covariates associated with patient PFS among a large list of patient- and tumor-related variables. Results: We evaluated 638 HR+/HER2- aBC patients treated with ET plus CDK4/6i at six Italian Institutions between January 2017 and May 2021. High baseline lymphocyte counts were independently associated with longer PFS [median PFS (mPFS) 20.1 versus 13.2 months in high versus low lymphocyte patients, respectively; adjusted Hazard Ratio (aHR): 0.78; 95% confidence interval (CI): 0.66-0.92; p = 0.0144]. Moreover, patients experiencing a lower early reduction of lymphocyte counts had significantly longer PFS when compared to patients undergoing higher lymphocyte decrease (mPFS 18.1 versus 14.5 months; aHR: 0.82; 95% CI: 0.73-0.93; p = 0.0037). Patients with high baseline lymphocytes and undergoing a lower reduction, or even an increase, of lymphocyte counts during CDK4/6i therapy experienced the longest PFS, while patients with lower baseline lymphocytes and undergoing a higher decrease of lymphocytes had the lowest PFS (mPFS 21.4 versus 11 months, respectively). Conclusion: Baseline and on-treatment modifications of peripheral blood lymphocytes have independent prognostic value in HR+/HER2- aBC patients. This study supports the implementation of clinical strategies to boost antitumor immunity in patients with HR+/HER2- aBC treated with ETs plus CDK4/6i.

Clinicopathological features and survival outcomes of luminal-like breast tumors with estrogen receptor loss at metastatic recurrence: A case-control study.

INTRODUCTION: Estrogen receptor (ER) loss at metastatic relapse occurs in up to 20% of luminal-like primary breast tumors. Data about clinicopathological features associated with ER loss and its prognostic significance are limited. METHODS: In a nested-case-control study, we compared clinicopathological characteristics and clinical outcomes between a cohort of 51 patients with primary ER+ /HER2- and paired triple-negative metastasis (LUM-TN) and two control cohorts of paired early-metastatic ER+ /HER2- (LUM-LUM, n = 50) and triple-negative (TN-TN, n = 49) breast cancers. Stromal tumor-infiltrating lymphocytes (TILs) were assessed according to the TILs Working Group recommendations as continuous and discrete variables with cutoffs (20%, 40%). RESULTS: LUM-TN tumors had lower ER expression than LUM-LUM tumors, but lower grade and Ki67 than TN-TN cases. Median distant-metastasis free survival was similar for LUM-TN and LUM-LUM cohorts, but significantly longer than in TN-TN cases (log-rank P < 0.001). LUM-TN and TN-TN cohorts had a comparable survival from the time of metastatic recurrence, which was significantly shorter than in patients with LUM-LUM tumors (log-rank P < 0.001). High TILs were associated with worse outcomes in patients with ER loss (P < 0.001). CONCLUSIONS: Breast tumors with ER loss at metastatic relapse have intermediate features and outcomes compared with metastatic luminal-like and ab initio triple-negative tumors. Further investigation on the biological mechanisms underpinning the loss of ER expression is ongoing.

HER2-positive breast cancer: cotargeting to overcome treatment resistance.

PURPOSE OF REVIEW: The introduction in clinical practice of anti-HER2 agents changed the prognosis of patients with HER2-positive (HER2+) breast cancer in both metastatic and early setting. Although the incomparable results obtained in the last years with the approval of new drugs targeting HER2, not all patients derive benefit from these treatments, experiencing primary or secondary resistance. The aim of this article is to review the data about cotargeting HER2 with different pathways (or epitopes of receptors) involved in its oncogenic signaling, as a mechanism to overcome resistance to anti-HER2 agents. RECENT FINDINGS: Concordantly to the knowledge of the HER2+ breast cancer heterogeneity as well as new drugs, novel predictive biomarkers of response to anti-HER2 treatments are always raised helping to define target to overcome resistance. Cotargeting HER2 and hormone receptors is the most well known mechanism to improve benefit in HER2+/HR+ breast cancer. Additional HER2-cotargeting, such as, with PI3K pathway, as well as different HERs receptors or immune-checkpoints revealed promising results. SUMMARY: HER2+ breast cancer is an heterogenous disease. Cotargeting HER2 with other signaling pathways involved in its mechanism of resistance may improve patient outcomes. Research efforts will continue to investigate novel targets and combinations to create more effective treatment regimes.

The rare entity of gastrointestinal leiomyosarcomas: An Italian multicenter retrospective study in high-volume referral centers.

BACKGROUND: After a huge efficacy of imatinib in treating patients with gastrointestinal stromal tumors (GISTs) was proven, a maximum effort was made to make a differential diagnosis between GISTs and gastrointestinal leiomyosarcomas (GI-LMS), showing the latter to be an extremely rare tumor entity. Limited data on GI-LMS biology, clinical behavior and drug-sensibility are available, and the clinical decision-making in this subgroup of patients is usually challenging. METHODS: We conducted a multicenter, retrospective observational study on patients with diagnosed GI-LMS from 2004 to 2020 within six high-volume referral centers in Italy. RESULTS: Thirty-three patients had diagnosis of KIT-negative GI-LMS confirmed by sarcoma-expert pathologist. The most common site of origin was the intestine. Twenty-two patients had localized disease and underwent surgery: with a median follow-up of 72 months, median disease-free survival was 42 months. Overall survival (OS)-rate at 5 years was 73% and median OS was 193 months. Five out of 10 patients with local relapse received a salvage surgery, and 2/5 remained with no evidence of disease. Thirteen patients received neoadjuvant (6) or adjuvant (7) chemotherapy, and 2/13 patients remained free from relapse. The median OS for patients with metastatic LMS was 16.4 months. CONCLUSION: GI-LMS is very rare and extremely aggressive subgroup of sarcomas with a high tendency to systemic spread. Localized GI-LMS at diagnosis may be cured if treated with adequate surgery with or without (neo) adjuvant chemotherapy, while de-novo metastatic disease appeared to have a poor prognosis. Clinical effort to understand GI-LMS biology and clinical behavior and to develop active treatment strategy, especially for metastatic-disease, is warranted.

Metaplastic breast cancer: an all-round multidisciplinary consensus.

Metaplastic breast cancer (MpBC) is a rare and aggressive histologic subtype of breast cancer (BC) characterized by the presence of at least two cellular types, commonly epithelial and mesenchymal components. Despite growing evidence that MpBC is a unique entity, it has long been treated as a variant of nonspecial type (NST) BC. MpBC typically shows the phenotype of triple-negative breast cancer (TNBC), but compared to NST-TNBC, it is a relatively chemorefractory tumor associated with worse outcomes. Therefore, there is an urgent need to develop management guidelines specifically for MpBC to improve the prognosis of patients with early MpBC. This expert consensus aims to guide diagnosis and standardize clinical management of early MpBC among treating physicians. We provide guidance on the challenging radiological and pathological diagnosis of MpBC. Evidence on the involvement of genetic predisposition in the development of MpBC is also explored. We emphasize the importance of a multidisciplinary approach for the treatment of patients with early MpBC. The optimal surgery and radiotherapy approach is presented, as well as the opportunity offered by novel therapeutic approaches to increase treatment response in this chemoresistant subtype. Appropriate management of patients with MpBC is critical to reduce the high risk of local and distant recurrence that characterizes this disease.

Prognostic significance of HER2-low status in HR-positive/HER2-negative advanced breast cancer treated with CDK4/6 inhibitors.

Whether Human Epidermal growth factor Receptor 2 (HER2)-low status has prognostic significance in HR + /HER2- advanced Breast Cancer (aBC) patients treated with first-line Endocrine Therapy plus CDK 4/6 inhibitors remains unclear. In 428 patients evaluated, HER2-low status was independently associated with significantly worse PFS and OS when compared with HER2-0 status. Based on our findings, HER2-low status could become a new prognostic biomarker in this clinical setting.

Evolution of biological features of invasive lobular breast cancer: Comparison between primary tumour and metastases.

BACKGROUND: Invasive lobular carcinoma (ILC) has unique clinical-biological features. Phenotypical differences between primary tumours (PTs) and metastases (M) have been described for invasive ductal carcinoma, but data on ILC are limited. METHODS: We retrospectively analysed patients with recurrent ILC from our institution from 2013 to 2020. We evaluated the discordance of the oestrogen receptor (ER), progesterone receptor (PgR) and HER2 between PT and M, to understand prognostic and therapeutic implications. RESULTS: Thirteen percent (n = 91) of all patients had ILC. We observed 15%, 44% and 5% of ER, PgR and HER2 status discordance between PT and M. ER/PgR discordance was related to receptor loss and HER2 mainly due to gain. PT presented a luminal-like phenotype (93%); 6% and 1% were triple-negative (TNBC) and HER2-positive. In M, there was an increase in TNBC (16%) and HER2-positive (5%). Metastasis-free survival and overall survival (OS) were different according to clinical phenotype, with poorer prognosis for HER2+ and TNBC (p < 0.001); OS after metastatic progression did not differ across phenotypes (p = 0.079). In luminal-like ILC (n = 85) at diagnosis, we found that OS after relapse was poorer in patients experiencing a phenotype switch to TNBC but improved in patients with HER2 gain (p = 0.0028). Poorer survival was reported in patients with a PgR and/or ER expression loss of ≥25%. There was HER2-low enrichment in M1 (from 37% to 58%): this change was not associated with OS (p > 0.05). CONCLUSION: Our results suggest that phenotype switch after metastatic progression may be associated with patients' outcomes. Tumour biopsy in recurrent ILC could drive treatment decision-making, with prognostic implications.

New Concepts in Cardio-Oncology.

Cancer and cardiovascular disease are the two major causes of morbidity and mortality in worldwide. Discovering new therapeutic agents for the management of breast cancer (BC) has increased the numbers of cancer survivors but with the risk of cardiovascular adverse events (CV-AEs). All drugs can potentially damage the cardiovascular system, with different types of clinical manifestations from ischemic myocardial disease to vasculitis, thrombosis or pericarditis. An early detection of CV-AEs guarantees an earlier treatment, which is associated with better outcomes. Cardio-oncology field enlarged its studies to improve prevention, monitoring and treatment of all cardiotoxic manifestations related to old or modern oncological agents. A multidisciplinary approach with a close partnership between oncologists and cardiologists is essential for an optimal management and therapeutic decision-making. The aim of this chapter is to review all types of cardiotoxic manifestations related to novel and old agents approved for treatment of BC patients including chemotherapy, anti-HER2 agents, cyclin-dependent kinase 4/6 inhibitors, PolyADP-ribose polymerase (PARP) inhibitors, antiangiogenic drugs and immunotherapy. We also focused our discussion on prevention, monitoring, treatment, and management of CV-AEs.

PIK3CAMutations in Breast Cancer Subtypes Other Than HR-Positive/HER2-Negative.

The phosphoinositide 3-kinase (PI3K) pathway plays a key role in cancer, influencing growth, proliferation, and survival of tumor cells. PIK3CA mutations are generally oncogenic and responsible for uncontrolled cellular growth. PI3K inhibitors (PI3Ki) can inhibit the PI3K/AKT/mTOR pathway, although burdened by not easily manageable toxicity. Among PI3Ki, alpelisib, a selective p110α inhibitor, is approved for the treatment of hormone receptor (HR)+/HER2- PIK3CA mutant metastatic breast cancer (BC) that has progressed to a first line endocrine therapy. PIK3CA mutations are also present in triple negative BC (TNBC) and HER2+ BC, although the role of PI3K inhibition is not well established in these subtypes. In this review, we go through the PI3K/AKT/mTOR pathway, describing most common mutations found in PI3K genes and how they can be detected. We describe the available biological and clinical evidence of PIK3CA mutations in breast cancers other than HR+/HER2-, summarizing clinical trials investigating PI3Ki in these subtypes.

The triple negative breast cancer drugs graveyard: a review of failed clinical trials 2017-2022.

INTRODUCTION: Triple-negative breast cancer (TNBC) accounts for 15-20% of breast cancers (BC) and has the worst prognosis. It is characterized by the absence of both hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2). TNBC has more limited therapeutic options compared to other subtypes, meaning that there is still a long way to go to discover target treatments. AREAS COVERED: Our review aims to summarize phase II/III clinical trials enrolling patients with TNBC that have been published between 2017 and 2022 but failed to reach their primary endpoint. We here try to emphasize the limitations and weaknesses noted in negative studies and to point out unexpected results which might be useful to enhance the therapeutic approach to TNBC disease. EXPERT OPINION: A deeper understanding of the mechanisms behind TNBC heterogeneity allowed to enhance the knowledge of new prognostic and predictive biomarkers of response. However, it is also through several failed clinical trials that we were able to define new therapeutic approaches which improved TNBC patients' clinical outcomes. Nowadays, we still need to overcome several difficulties to fully recognize different intracellular and extracellular pathways that crosstalk in TNBC and the mechanisms of resistance to identify novel tailored-patients' therapies.

Avelumab plus axitinib in unresectable or metastatic type B3 thymomas and thymic carcinomas (CAVEATT): a single-arm, multicentre, phase 2 trial.

BACKGROUND: Patients with advanced type B3 thymoma and thymic carcinoma resistant to chemotherapy have few treatment options. We report the efficacy and safety results of the combination of the anti-PD-L1 inhibitor avelumab with the anti-angiogenesis drug axitinib in patients with advanced type B3 thymoma and thymic carcinoma. METHODS: CAVEATT was a single-arm, multicentre, phase 2 trial, conducted in two Italian centres (the European Instituteof Oncology and the Humanitas Institute, Milan) in patients with histologically confirmed type B3 thymoma or thymic carcinoma, with advanced stage of disease who had progressed after at least one line of platinum-based chemotherapy. Previous treatment with an anti-angiogenesis drug was allowed but not with immune checkpoint inhibitors. Other inclusion criteria were age 18 years or older, an Eastern Cooperative Oncology Group performance status of 0-2, progressive disease, and presence of measurable disease according to Response Evaluation Criteria In Solid Tumours (RECIST) version 1.1. Patients received avelumab 10 mg/kg intravenously every 2 weeks and axitinib 5 mg orally twice daily until disease progression or unacceptable toxicity. The primary endpoint was the centrally assessed overall response rate according to RECIST version 1.1. Patients who received at least one cycle of treatment and had at least one CT scan after treatment start at scheduled time point by protocol were judged assessable for response and were included in efficacy and safety analyses. This study is registered with EUDRACT, 2017-004048-38; enrolment is completed and follow-up is ongoing. FINDINGS: Between April 22, 2019, and June 30, 2021, 32 patients were enrolled. 27 patients had a thymic carcinoma, three a type B3 thymoma, and two a mixed type B3 thymoma and thymic carcinoma. 29 (91%) of 32 patients had stage IVB disease and 13 (41%) of 32 had been pretreated with an anti-angiogenesis drug. 11 of 32 patients had an overall response; thus the overall response rate was 34% (90% CI 21-50); no patients had a complete response, 11 (34%) had a partial response, 18 (56%) had stable disease, and in two patients (6%) progressive disease was the best response. The most common grade 3 or 4 adverse event was hypertension (grade 3 in six [19%] of 32 patients). Four (12%) of 32 patients developed serious adverse events that were new-onset immune-related adverse events, including one grade 3 interstitial pneumonitis, one grade 4 polymyositis, and two grade 3 polymyositis. There were no treatment-related deaths. INTERPRETATION: Avelumab combined with axitinib has promising anti-tumour activity and acceptable toxicity in patients with advanced type B3 thymoma and thymic carcinoma progressing after chemotherapy, and could emerge as a new standard treatment option in this setting. FUNDING: Pfizer.

Triple negative breast cancer: Pitfalls and progress.

Triple negative breast cancer (TNBC) is characterized by the lack of estrogen and progesterone receptor expression and lacks HER2 overexpression or gene amplification. It accounts for 10-15% of incident breast cancers and carries the worst prognosis. TNBC is overrepresented among Black and pre-menopausal women and is associated with significant psychological and treatment-related burdens, including financial toxicity. Like other breast cancers, TNBC is biologically heterogeneous, leading to diverse clinical and epidemiological behaviors, however, unlike the other clinical subtypes, in TNBC we still lack tumor-specific targeted therapy. Early TNBC outcomes have improved due to the intensification of therapies, including improvements in polychemotherapy and the addition of immunotherapy. Future efforts are needed to identify targetable aberrations for specific drug therapy, prevent immune evasion, and increase social-economic support. Given that the name TNBC illustrates its lack of specifically targeted and effective therapy, we look forward to being able to retire the name in favor of a group of targetable entities within what is now called "TNBC".

Refining risk stratification in HR-positive/HER2-negative early breast cancer: how to select patients for treatment escalation?

PURPOSE: Despite advances in adjuvant therapeutic strategies, many patients with hormone receptor (HR)-positive/HER2-negative early breast cancer (EBC) experience disease recurrence, even many years after primary surgery. The aim of this review is: (i) to point out the current clinical, pathological, and genomic features that contribute to define the risk of recurrence in HR-positive EBC, (ii) to explore the potential role of liquid biopsy-based assays for refining risk assessment, and (iii) to discuss future perspectives and innovative strategies to optimize risk stratification and select patients for treatment escalation. METHODS: We searched PubMed, EMBASE and Scopus to review the current evidence about risk stratification in patients with HR-positive EBC, and to identify studies deemed to have the highest scientific value. RESULTS: Risk stratification of HR-positive/HER2-negative relies on traditional clinicopathological features (age, menopausal status, tumor size, nodal status, tumor grading, HR expression level, and proliferation markers), along with newly developed genomic scores, which accurately predict risk of recurrence and survival. Multiparametric scores including both clinicopathological and genomic variables have the highest prognostication power, even if comparative studies have not defined which one should be preferred. In parallel, liquid biopsy-based showed to be a valuable tool to identify high risk patients. CONCLUSION: The most appropriate definition of "high" and "low" risk HR-positive EBC is still unclear. Accordingly, treatment escalation/de-escalation depending on recurrence risk remains challenging. Implementation of new tools for risk stratification, such as liquid biopsy-based assays, as well as development of novel treatment strategies are strongly warranted.

Evolution of low HER2 expression between early and advanced-stage breast cancer.

BACKGROUND: Low human epidermal growth factor receptor 2 (HER2) expression is emerging as an actionable biomarker for the treatment of breast cancer (BC) with novel anti-HER2 drugs. However, the evolution of this biomarker during the course of disease is still poorly characterised, and controversial data exist on its prognostic implications. METHODS: We reviewed data of patients with HER2-negative BC according to the latest ASCO/CAP guidelines referred between January 2014 and December 2020. We grouped patients based on the immunohistochemistry (IHC) expression of HER2, HER2-zero (IHC 0) and HER2-low subgroup (IHC 1+ or 2+/ISH-negative) and evaluated the evolution of HER2 expression between the primary tumour and the first biopsy collected in the advanced setting. Disease-free survival, overall survival and progression-free survival were compared between patients with HER2-zero and HER2-low expression on the primary tumour. RESULTS: 232 patients were included in the analysis. Among the overall population, there was a relevant discordance in HER2 expression between the primary tumour and the matched biopsy (K = 0.33, 95%CI 0.21-0.44): 44% of the HER2-zero primary tumour showed an increased HER2 score on biopsy, and 22% of the HER2-low primary tumours turned into HER2-IHC 0. The findings in the sub-populations of hormone-receptors positive (K = 0.32, 95%CI 0.19-0.45) and triple-negative tumours (K = 0.18, 95%CI -0.09-0.46) were consistent with the primary analysis. No difference in survival outcomes was observed between HER2-low and HER2-zero primary tumours. CONCLUSIONS: HER2-low expression is dynamic in BC and may be enriched in the advanced-stage setting. No prognostic significance was demonstrated for HER2-low expression.

Different Response to Immunotherapy According to Melanoma Histologic Subtype.

Superficial spreading melanoma (SSM) and nodular melanoma (NM) are the most common melanoma histologic subtypes and are characterized by different biological features. We retrospectively analyzed all consecutive patients with advanced melanoma, treated with anti-PD-1 and/or anti-CTLA-4 at our center, with data available on primary tumor subtype. The primary objective was to assess the association between histologic subtype and patients' outcomes. In addition, we analyzed whole-exome and whole-transcriptome sequencing data of a cohort of advanced melanoma to identify genes and related pathways, characterized by significant differences between NMs and SSMs. Twenty-one patients with NM and 39 with SSM, treated with anti-PD-1(53/60) as monotherapy or combined with anti-CTLA-4 (7/60), were analyzed. All known clinical-pathologic prognostic factors were well balanced between NM and SSM groups, except for the ECOG-PS score. The overall response rate was 52.4% (95% confidence interval, 29.8-74.3) in the NMs group versus 20.5% (9.3-36.5) in the SSMs group (P-value=0.02). The median progression-free survival and overall survival were, respectively, 13.9 and 44.5 months in the NMs group versus only 3.2 and 12 months in SSMs group (progression-free survival P-value=0.032; overall survival P-value=0.002). Multivariable analysis adjusting for the ECOG-PS, confirmed similar results. Whole-exome and whole-transcriptome data of 28 NMs and 21 SSMs were analyzed. No significant differences were observed in terms of both TMB and frequency of mutation in any gene. A total of 266 genes were overexpressed in NMs as compared with SSMs, and enrichment-analysis revealed a significant enrichment (false discovery rate<0.05) of genes belonging to immune-related pathways involved in antigens presentation mechanisms, response to interferon gamma and neutrophil activation. We provided clinical evidences suggesting a relevant association between melanoma histologic subtype and response to immunotherapy.