Predictors of mastectomy in breast cancer patients with complete remission of primary tumor after neoadjuvant therapy: A retrospective study.

INTRODUCTION: Neoadjuvant therapy (NAT) should increase the rate of breast-conserving surgery (BCS) in non-metastatic breast cancer (BC) patients, especially in those achieving tumor shrinkage. Still, the conversion from a pre-planned mastectomy to BCS in patients responding to NAT is not a widespread standard. We aimed to identify factors influencing surgical choices in this setting. MATERIALS AND METHODS: We retrospectively collected data of BC patients with complete remission of primitive tumor (ypT0) after NAT, treated with BCS or mastectomy in two Italian breast units. Predictors of mastectomy were explored using logistic regression. Distant recurrence and event-free survival were assessed in the BCS and mastectomy cohort. RESULTS: 243 patients were included, 147 (60.5 %) treated with BCS and 96 (39.5 %) treated with mastectomy. In the mastectomy group, there were more centrally-located, multiple and larger tumors. At univariate regression analysis, central location, baseline tumor extension on ultrasound (US) and magnetic resonance imaging (MRI), multiple foci and clinical stage were significantly associated with the chance of receiving mastectomy. At multivariate analysis, only baseline focality on US and extension on MRI retained significance as predictors of mastectomy. Distant recurrence and event-free survival were significantly longer in patients undergoing BCS. CONCLUSION: Baseline tumor extension and focality were the main predictors of mastectomy in patients with ypT0 after NAT. However, BCS did not negatively affect survival outcomes in our cohort. An effort should be made to avoid potentially unnecessary mastectomy in this population, aiming at minimizing surgery-associated toxicities and improving patients' quality of life.

Corrigendum: Aromatase inhibitors: the journey from the state of the art to clinical open questions.

[This corrects the article DOI: 10.3389/fonc.2023.1249160.].

Novel Thienoduocarmycin-Trastuzumab ADC Demonstrates Strong Antitumor Efficacy with Favorable Safety Profile in Preclinical Studies.

New antibodies-drug conjugate (ADC) payloads overcoming chemoresistance and killing also poorly proliferating tumors at well-tolerated doses are much desired. Duocarmycins are a well-known class of highly potent cytotoxic agents, with DNA minor groove-binding and alkylation properties, active also in chemoresistant tumors. Although different duocarmycin derivatives have been used during the years as payloads for ADC production, unfavorable physicochemical properties impaired the production of ADCs with optimal features. Optimization of the toxin to balance reactivity and stability features and best linker selection allowed us to develop the novel duocarmycin-like payload-linker NMS-P945 suitable for conjugation to mAbs with reproducible drug-antibody ratio (DAR) >3.5. When conjugated to trastuzumab, it generated an ADC with good internalization properties, ability to induce bystander effect and immunogenic cell death. Moreover, it showed strong target-driven activity in cells and cytotoxic activity superior to trastuzumab deruxtecan tested, in parallel, in cell lines with HER2 expression. High in vivo efficacy with cured mice at well-tolerated doses in HER2-driven models was also observed. A developed pharmacokinetic/pharmacodynamic (PK/PD) model based on efficacy in mice and cynomolgus monkey PK data, predicted tumor regression in patients upon administration of 2 doses of trastuzumab-NMS-P945-ADC at 0.5 mg/kg. Thus, considering the superior physicochemical features for ADC production and preclinical results obtained with the model trastuzumab ADC, including bystander effect, immunogenic cell death and activity in chemoresistant tumors, NMS-P945 represents a highly effective, innovative payload for the creation of novel, next-generation ADCs.

Abemaciclib-associated Diarrhea: An Exploratory Analysis of Real-life Data.

BACKGROUND/AIM: Abemaciclib is a cyclin-dependent kinase 4/6 inhibitor approved in combination with endocrine therapy for treating hormone receptor-positive and human epidermal growth factor receptor 2-negative early and advanced breast cancer patients. The safety profile of abemaciclib is characterized by frequent gastrointestinal toxicity, especially diarrhea. Therefore, we performed an exploratory analysis of clinical factors that may be potentially associated with diarrhea in patients treated with abemaciclib plus endocrine therapy. PATIENTS AND METHODS: Factors potentially predisposing to diarrhea were selected, such as age ≥70 years, concomitant medications and diseases, diet, and use of laxatives. These variables were correlated with the onset of grade 2/3 diarrhea in a cohort of patients treated with abemaciclib from advanced breast cancer. Univariate and multivariate analysis was performed. Sensitivity and specificity were tested using the ROC curve. RESULTS: Eighty women with advanced breast cancer were included in the study. The univariate analysis found a statistically significant correlation between grade 2/3 diarrhea and age ≥70 years, polypharmacy, and concomitant gastrointestinal diseases (p<0.05). In the multivariate analysis, the number of risk factors significantly correlated with the outcome of interest (p<0.0001). ROC analysis showed our model's 82% sensitivity and 75% specificity. CONCLUSION: Taking into account specific pre-existing factors, it is possible to estimate the risk of diarrhea in hormone receptor-positive and human epidermal growth factor receptor 2-negative - advanced breast cancer patients, candidates for abemaciclib plus endocrine therapy. In these subjects, implementing proactive prevention and adopting a dose-escalation strategy may represent practical approaches to decrease the abemaciclib toxicity burden.

Aromatase inhibitors: the journey from the state of the art to clinical open questions.

Breast cancer is a major cause of death among females. Great advances have been made in treating this disease, and aromatase inhibitors (AIs) have been recognized as the cornerstone. They are characterized by high efficacy and low toxicity. The authors reviewed the available literature and defined state-of-the-art AI management. This study was designed to assist clinicians in addressing the need to equally weigh patients' needs and disease control rates in their everyday clinical practice. Today, AIs play a central role in the treatment of hormone receptor-positive breast cancer. In this study, an expert panel reviewed the literature on the use of AIs, discussing the evolution of their use in various aspects of breast cancer, from pre- and postmenopausal early breast cancer to metastatic breast cancer, along with their management regarding efficacy and toxicity. Given the brilliant results that have been achieved in improving survival in everyday clinical practice, clinicians need to address their concerns about therapy duration and the adverse effects they exert on bone health, the cardiovascular system, and metabolism. Currently, in addition to cancer treatment, patient engagement is crucial for improving adherence to therapy and supporting patients' quality of life, especially in a selected subset of patients, such as those receiving an extended adjuvant or combination with targeted therapies. A description of modern technologies that contribute to this important goal is provided.

Molecular Analysis of Luminal Androgen Receptor Reveals Activated Pathways and Potential Therapeutic Targets in Breast Cancer.

BACKGROUND/AIM: Triple-negative breast cancers represent 15% of all mammary malignancies and encompass several entities with different genomic characteristics. Among these, luminal androgen receptor (LAR) tumors express the androgen receptor (AR) and are characterized by a genomic profile which resembles luminal breast cancers. Moreover, LAR malignancies are usually enriched in PIK3CA, KMTC, CDH, NF1, and AKT1 alterations. Still, molecular features, clinical behavior and prognosis of this variant remain controversial, while identification of effective treatments represents an unmet medical need. Additionally, the predictive role of the AR is unclear. MATERIALS AND METHODS: We performed an extensive next generation sequencing analysis using a commercially available panel in a cohort of patients with LAR breast cancer followed at two local Institutions. We next employed bioinformatic tools to identify signaling pathways involved in LAR pathogenesis and looked for potentially targetable alterations. RESULTS: Eight patients were included in the study. In our cohort we found 26 known genetic alterations (KGAs) in 15 genes and 64 variants of unknown significance (VUS) in 59 genes. The most frequent KGAs were single nucleotide variants in PIK3CA, HER2, PTEN and TP53. Among VUS, CBFB, EP300, GRP124, MAP3K1, RANBP2 and TSC2 represented recurrently altered genes. We identified five signaling pathways (MAPK, PI3K/AKT, TP53, apoptosis and angiogenesis) involved in the pathogenesis of LAR breast cancer. Several alterations, including those in PIK3CA, ERBB2 and PI3K/AKT/mTOR signaling, were potentially targetable. CONCLUSION: Our findings confirm a role for PI3K/AKT/mTOR signaling in the pathogenesis of LAR breast cancers and indicate that targeting this pathway, along with ERBB2 mutations, may represent an additional therapeutic strategy which deserves further exploration in larger studies.

Is Anti-Müllerian Hormone a Marker of Ovarian Reserve in Young Breast Cancer Patients Receiving a GnRH Analog during Chemotherapy?

Introduction: Anti-Müllerian hormone (AMH) is the most reliable biomarker of ovarian reserve; however, its role in predicting ovarian recovery after chemotherapy is unclear. Administration of a GnRH analog (GnRHa) during chemotherapy significantly reduces the ovarian failure rate and increases the pregnancy rate. The available data on the behavior of AMH during concurrent administration of chemotherapy and GnRHa are inconsistent. We investigated whether concurrent administration of triptorelin and adjuvant chemotherapy might reduce the expected drop of AMH. Methods: Eligible patients were premenopausal women aged <40 years, with a diagnosis of early breast cancer, and candidates to 4-8 cycles of adjuvant chemotherapy. Triptorelin (3.75 mg i.m.) was started before chemotherapy and administered every 4 weeks thereafter. The principal endpoint was the proportion of patients with an AMH percent change ≤50% between 12 months after chemotherapy and basal levels. The secondary endpoint was the proportion of patients achieving postchemotherapy AMH levels above the threshold of 0.2 ng/mL. Results: Fifty patients were enrolled, 31 of whom had blood samples available at baseline and 1 year after the end of chemotherapy. AMH decreased to nearly undetectable levels after chemotherapy and recovered after 12 months, but they did not exceed 1 tenth of the pretreatment levels. As for the secondary endpoint, 15 of the 31 patients recovered AMH levels above the threshold. Conclusions: This study did not reach its principal endpoint; however, the rate of 48% of patients who recovered AMH above threshold levels favorably compared with those in studies without concurrent GnRHa, supporting a better recovery of AMH with triptorelin.

Reactions and countermeasures of medical oncologists towards the incoming COVID-19 pandemic: a WhatsApp messenger-based report from the Italian College of Chief Medical Oncologists.

BACKGROUND: This descriptive, unplanned investigation has been undertaken to report reactions, attitudes and countermeasures which have been put in place and implemented by medical oncology units facing the COVID-19 outbreak in Southern Italy. MATERIALS AND METHODS: Data have been retrospectively obtained from the time-related analysis of conversations via a WhatsApp messenger-based group chat between the medical directors belonging to the Italian College of Medical Oncology Directors. Overall number, intensity and time trend of conversations related to reactions during the 4 weeks of observation related to the crucial events which occurred between 24 February and 28 March, 2020 2020 are included. A sentiment analysis of conversations was also carried out. RESULTS: We report 956 conversations among 19 medical oncology units related to reactions to the crucial events, such as epidemic spread, Government ordinances and guidelines during the 4 weeks of observation. Data show significant awareness of problems linked to the COVID-19 spread among oncologists and rapid diffusion of countermeasures. Actions taken were correlated time wise to crucial events. A correlation between conversations and the volume of activity of oncology units was found. By analysing the sentiment analysis of raw data, positive emotions were reduced in percentage over the weeks. A significant increase in negative emotions was observed as the outbreak impacted on the healthcare system. CONCLUSION: In our experience, the WhatsApp instant-messaging system seems to be a useful tool to share news and reactions between medical oncologists to rapidly implement necessary health measures and answers to most cancer patients' needs and queries in the COVID-19 pandemic scenario.

Correction: The prognostic significance of combined androgen receptor, E-Cadherin, Ki67 and CK5/6 expression in patients with triple negative breast cancer.

[This corrects the article DOI: 10.18632/oncotarget.20293.].

The impact of cancer: An Italian descriptive study involving 500 long-term cancer survivors.

INTRODUCTION: The well-being and quality of life (QoL) of long-term cancer survivors may be affected, both positively and negatively, by psychosocial factors related to the experience of being a cancer patient. We investigated whether, in long-term cancer survivors, the psychosocial impacts of cancer associate with socio-demographic-clinical variables; whether, within the positive and negative dimensions taken separately, some impacts are more intense than others; and whether these impacts explain QoL. METHODS: Italian long-term cancer survivors (n = 500) completed the Impact of Cancer (IOC-V2) and Short Form 36 Health Survey (SF-36) questionnaires. RESULTS: The IOC-V2 negative impact score associated with gender, education, occupational status and health issues, whereas no association was found between the positive impact score and socio-demographic-clinical variables. Of the positive impacts, Altruism/Empathy was the highest (p < 0.001); Positive self-evaluation was higher than Health awareness (p = 0.001); and Meaning of cancer was the lowest (p < 0.001). Among the negative impacts, Worry was the highest (p < 0.001), whereas Body changes concerns was higher than both Appearance concerns (p < 0.001) and Life Interferences (p < 0.001). The assessed impacts explained more than 25% of the variance of both physical and mental functioning scores. CONCLUSIONS: The provided data document psychosocial factors affecting QoL in Italian long-term cancer survivors.

Neutrophil Elastase Promotes Linker Cleavage and Paclitaxel Release from an Integrin-Targeted Conjugate.

This work takes advantage of one of the hallmarks of cancer, that is, the presence of tumor infiltrating cells of the immune system and leukocyte-secreted enzymes, to promote the activation of an anticancer drug at the tumor site. The peptidomimetic integrin ligand cyclo(DKP-RGD) was found to accumulate on the surface of αv ß3 integrin-expressing human renal cell carcinoma 786-O cells. The ligand was conjugated to the anticancer drug paclitaxel through a Asn-Pro-Val (NPV) tripeptide linker, which is a substrate of neutrophil-secreted elastase. In vitro linker cleavage assays and cell antiproliferative experiments demonstrate the efficacy of this tumor-targeting conjugate, opening the way to potential therapeutic applications.

Eribulin mesylate use as third-line therapy in patients with metastatic breast cancer (VESPRY): a prospective, multicentre, observational study.

BACKGROUND: In real-world practice, eribulin mesylate provides significant survival benefit, with a manageable safety profile in heavily pretreated patients with metastatic breast cancer (MBC). METHODS: In this prospective, open-label, multicentre, observational study we evaluated the effectiveness and tolerability of eribulin as third-line treatment in a homogeneous population. The primary endpoints were the safety profile and response in metastatic sites; secondary endpoints included the response in different subtypes, overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). RESULTS: From 2013 to 2016, 118 women were treated in 21 Sicilian institutions; the median age was 58 years (range 29-79), with 69% of patients under 65. The median cycles of eribulin were 5.5 (range 1-26). The most common adverse event was neutropenia (9.3%, 3 cases of grade 3, 4 of grade 4); only 1 case of QT prolongation was reported. Eribulin was effective in controlling metastatic disease in all sites, and it achieved the highest ORR in brain (16%) and liver (14.9%). Median OS was 31.8 months (95% CI 27.9-34.4) and median PFS 5.5 months (95% CI 4.2-6.6). PFS was 5.2 months (95% CI 2.8-8.4) in patients with triple-negative subtype. Median PFS was longer in patients over 65 years (6.1 months, 95% CI 4.4-8.3). In patients who had visceral metastases PFS was 5.5 months (95% CI 95% 3.5-6.6) and OS 33.9 months (95% CI 29.8-40.8). CONCLUSIONS: Eribulin as third-line treatment shows an acceptable safety profile and a substantial antitumour activity in the treatment of MBC, even in elderly patients and in those with visceral disease.

T-DM1 and brain metastases: Clinical outcome in HER2-positive metastatic breast cancer.

BACKGROUND: We reported the results of an Italian large retrospective analysis that evaluated the effectiveness and safety of T-DM1 in 'field-practice' breast cancer patients. We performed a sub-analysis to investigate the clinical activity of T-DM1 in patients with brain metastases (BMs). METHODS: The records of 87 adult women with HER2-positive breast cancer and BMs treated with T-DM1 were reviewed. Their clinical outcomes were compared with those of 216 patients without central nervous system (CNS) involvement. RESULTS: Response to T-DM1 treatment in BMs was available for 53 patients in the BM group (60.9%): two patients reported a complete response (3.8%), 11 patients obtained partial response (20.7%; overall response rate: 24.5%), 16 patients had a stable disease (30.1%). Regarding extracranial disease, a total of 77 and 191 patients were evaluable for response in BM group and non-BM group, respectively. The overall response rate was 35.1% in the BM group and 38.3% in the non-BM group; disease control rate was 53.3% and 66.6%, respectively. At a median follow-up of 16 months (range: 1-55), median cumulative progression-free survival (PFS) was 7 months (95% CI: 5.4-8.6) in the BM group and 8 months (95% CI: 5.7-10.3) in the non-BM group. In the second-line setting, PFS was 5 (95% CI: 3.1-6.9) versus 11 (95% CI: 7.1-14.9) months (p = 0.01). Overall survival was 14 months (95% CI: 12.2-15.8) in the BM group and 32 months (95% CI: 24.4-39.6) in the non-BM group (p < 0.0001). CONCLUSIONS: T-DM1 is active in breast cancer patients with BMs.

Long-term quality of life profile in oncology: a comparison between cancer survivors and the general population.

PURPOSE: Understanding the quality of life (QoL) of cancer survivors is relevant to both clinical practice and health care policy. The current study compared the QoL profile in this specific population with that of a normative sample for the general population, as well as with those of both healthy and oncological patients normative sub-samples. In addition, associations between the obtained QoL profile and the main socio-demographic and clinical characteristics of the sample were examined. METHODS: Three hundred and ninety-two adult long-term cancer survivors (i.e., people 5 + years from their cancer diagnosis who were free from it and its treatments) were enrolled during follow-up visits and compiled the Short Form 36 Health Survey. RESULTS: In comparison with the normative data for the adult general population, the present sample showed lower scores in Physical functioning, Role-physical limitation, and Role-emotional limitations (all differences were both statistically and clinically significant); the difference in Vitality was only statistically significant. In all eight SF-36 scales, scores of the present sample were clinically and statistically lower than those of the normative healthy subsample, whereas they were statistically and clinically higher than those of normative subsample which had experienced cancer, except for Role-physical limitation. The QoL profile was associated with gender (p = 0.002), age (p = 0.001), education (p < 0.001), occupational status (p < 0.001), and the presence of other health issues (p < 0.001). CONCLUSION: These data support the utility of rehabilitative programs which integrate both healthcare and social interventions. In addition, they encourage the monitoring of the health status of this specific population, within a broad frame which simultaneously takes into consideration health and QoL.

Phase II Study of Everolimus in Patients With Thymoma and Thymic Carcinoma Previously Treated With Cisplatin-Based Chemotherapy.

Purpose No effective salvage treatments are available for patients with advanced/recurrent thymoma (T) or thymic carcinoma (TC) who have progressed after platinum-based chemotherapy. This study evaluated the activity of everolimus in patients with advanced/recurrent T or TC previously treated with cisplatin-containing chemotherapy. Patients and Methods This was a single-arm, single-stage, open-label, multicenter, phase II trial. Patients received oral everolimus 10 mg/d until disease progression, unacceptable toxicity, or patient refusal. A Fleming phase II trial was designed. The null hypothesis of a true disease control rate (DCR) of 40% was tested against a one-sided alternative of a true DCR of 60% (α = ß = 0.10): If disease control were achieved in ≥ 21 of the first 41 evaluable patients, everolimus could be recommended for further evaluation. Progression-free survival, overall survival, and safety were also evaluated. Results From 2011 to 2013, 51 patients were enrolled (T, n = 32; TC, n = 19). Complete remission was observed in one patient with TC, partial response in five patients (T, n = 3; TC, n = 2), and stable disease in 38 patients (T, n = 27; TC, n= 11), with a DCR of 88% (T,: 93.8%; TC, 77.8%). With a median follow up of 25.7 months, median progression-free survival was 10.1 months (T,: 16.6 months; TC, 5.6 months), and median overall survival was 25.7 months (T, not reached; TC, 14.7 months). Fourteen patients had a serious drug-related adverse event; of these patients, nine permanently discontinued treatment. Three patients died of pneumonitis while in the study. Immunohistochemical positivity for p4E-BP1 or insulin-like growth factor-1 receptor was statistically significantly related to a shorter survival. Conclusion Everolimus may induce durable disease control in a high percentage of patients with T or TC, albeit with a potential high risk of fatal pneumonitis.

Ado-trastuzumab emtansine (T-DM1) in HER2+ advanced breast cancer patients: does pretreatment with pertuzumab matter?

AIM: We evaluated the outcomes of patients treated with ado-trastuzumab emantasine (T-DM1) after first-line pertuzumab/trastuzumab, compared with those receiving a trastuzumab-only-based regimen. PATIENTS & METHODS: Patients who received second-line T-DM1 after pertuzumab/trastuzumab (n = 34) were compared with those who received only trastuzumab (n = 73). RESULTS: Overall response rate was 33.3% in patients with prior pertuzumab and 57.1% in the remaining subjects. Disease control rate was 47 and 43%, respectively, and the clinical benefit rate was 43.3 and 71.1%, respectively. Median progression-free survival was 5.0 and 11.0 months, respectively (hazard ratio: 2.02; 95% CI: 1.14-3.58; p = 0.01). CONCLUSION: Patients treated with T-DM1 who previously received pertuzumab present poorer clinical outcomes compared with those receiving a trastuzumab-only-based regimen in the first-line setting.

Efficacy and safety of T-DM1 in the 'common-practice' of HER2+ advanced breast cancer setting: a multicenter study.

Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate approved for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive, metastatic breast cancer (mBC). The aim of this 'field-practice' study was to investigate the efficacy and safety of T-DM1, focusing on treatment line, previous lapatinib treatment and patterns of metastasis. Three hundred and three patients with HER2-positive mBC who received T-DM1 were identified by reviewing the medical records of 24 Italian Institutions. One hundred fourty-nine (49%) and 264 (87%) had received prior hormonal treatment and/or anti-HER2 targeted therapy, respectively. Particularly, 149 patients had been previously treated with lapatinib. The objective response rate (ORR) was 36.2%, and 44.5% when T-DM1 was administrated as second-line therapy. Considering only patients with liver metastases, the ORR was 44.4%. The median progression-free survival (PFS) was 7.0 months in the overall population, but it reached 9.0 and 12.0 months when TDM-1 was administered as second- and third-line treatment, respectively. In conclusion, in this 'real-word' study evaluating the effects of T-DM1 in patients with HER2-positive mBC who progressed on prior anti-HER2 therapies, we observed a clinically-relevant benefit in those who had received T-DM1 in early metastatic treatment-line and in subjects previously treated with lapatinib.

Multivalency Increases the Binding Strength of RGD Peptidomimetic-Paclitaxel Conjugates to Integrin αV ß3.

This work reports the synthesis of three multimeric RGD peptidomimetic-paclitaxel conjugates featuring a number of αV ß3 integrin ligands ranging from 2 to 4. These constructs were assembled by conjugation of the integrin αV ß3 ligand cyclo[DKP-RGD]-CH2 NH2 with paclitaxel via a 2'-carbamate with a self-immolative spacer, the lysosomally cleavable Val-Ala dipeptide linker, a multimeric scaffold, a triazole linkage, and finally a PEG spacer. Two monomeric conjugates were also synthesized as reference compounds. Remarkably, the new multimeric conjugates showed a binding affinity for the purified integrin αV ß3 receptor that increased with the number of integrin ligands (reaching a minimum IC50 value of 1.2 nm for the trimeric), thus demonstrating that multivalency is an effective strategy to strengthen the ligand-target interactions.

Immunoexpression of lactoferrin in triple-negative breast cancer patients: A proposal to select a less aggressive subgroup.

Triple-negative breast cancer (TNBC) indicates a subset of breast carcinomas that does not express estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2). According to the literature, TNBCs are aggressive tumors, characterized by a high incidence of recurrence and a high risk of disease progression. Lactoferrin (LF) is a single-chain, iron-binding glycoprotein of ~700 amino acids, which is involved in a wide range of biological activities, including iron-trafficking and carcinogenesis. The present study aimed to assess LF expression in human TNBC samples and the possible correlation with clinico-pathological parameters associated with biological aggressiveness. LF immunohistochemical expression was investigated in formalin-fixed, paraffin-embedded samples of human TNBC. Cases were analyzed according to an intensity distribution (ID) score, and only those showing an ID score of >2 were considered as positive for LF. LF immunostaining was encountered in 26.15% cases. A significant correlation was found between LF expression and a low Ki-67 labeling index (P=0.040), the absence of recurrence (P=0.010) and alive status (P=0.020). LF may assist in identifying a subset of TNBC with less aggressive biological behavior. The meaning of LF expression in TNBC remains unclear and is controversial. The present findings indicated that LF expression is correlated with a low growth fraction in these tumors. Thus, it is possible that the inhibition of the LF axis may be a valid therapeutic target for TNBC, and this should be confirmed by future studies.

Tumor Targeting with an isoDGR-Drug Conjugate.

Herein we report the first example of an isoDGR-drug conjugate (2), designed to release paclitaxel selectively within cancer cells expressing integrin αV ß3 . Conjugate 2 was synthesized by connecting the isoDGR peptidomimetic 5 with paclitaxel via the lysosomally cleavable Val-Ala dipeptide linker. Conjugate 2 displayed a low nanomolar affinity for the purified integrin αV ß3 receptor (IC50 =11.0 nm). The tumor targeting ability of conjugate 2 was assessed in vitro in anti-proliferative assays on two isogenic cancer cell lines characterized by different integrin αV ß3 expression: human glioblastoma U87 (αV ß3 +) and U87 ß3 -KO (αV ß3 -). The isoDGR-PTX conjugate 2 displayed a remarkable targeting index (TI=9.9), especially when compared to the strictly related RGD-PTX conjugate 4 (TI=2.4).