Novel HER-2 Targeted Therapies in Breast Cancer

Human epidermal growth factor 2 (HER-2)-positive breast cancer represents 15-20% of all breast cancer subtypes and has an aggressive biological behavior with worse prognosis. The development of HER-2-targeted therapies has changed the disease's course, having a direct impact on survival rates and quality of life. Drug development of HER-2-targeting therapies is a prolific field, with numerous new therapeutic strategies showing survival benefits and gaining regulatory approval in recent years. Furthermore, the acknowledgement of the survival impact of HER-2-directed therapies on HER-2-low breast cancer has contributed even more to advances in the field. The present review aims to summarize the newly approved therapeutic strategies for HER-2-positive breast cancer and review the new and exploratory HER-2-targeted therapies currently under development.

Prognostic Value of Tumor Budding for Early Breast Cancer

BACKGROUND

Tumor budding (TB) is a dynamic process associated with the epithelial-mesenchymal transition and a well-established prognostic biomarker for colorectal cancer. As part of the tumor microenvironment, tumor buds demonstrate increased cell motility and invasiveness. Current evidence demonstrates that high levels of TB correlate with disease progression and worst outcomes across different solid tumors. Our work aims to demonstrate the clinical applicability of TB analysis and its utility as a prognostic factor for patients with early breast cancer (EBC).

METHODS

Retrospective, single-center, observational study, enrolling patients with EBC diagnosed in a Portuguese hospital between 2014 and 2015. TB classification was performed according to the International Tumor Budding Conference 2016 guidelines.

RESULTS

A statistically significant relation was found between higher TB score and aggressive clinicopathological features (angiolymphatic/perineural invasion-p < 0.001; tumor size-p = 0.012; nuclear grading-p < 0.001; and Ki-67 index-p = 0.011), higher number of relapses (p < 0.001), and short disease-free survival (DFS) (p < 0.001).

CONCLUSION

We demonstrate that high TB correlates with shorter DFS and aggressive clinicopathological features used in daily practice to decide on the benefit of chemotherapy for EBC. TB represents a needed prognostic biomarker for EBC, comprising a new factor to be considered in the adjuvant decision-making process by identifying patients at a high risk of relapse and with higher benefit on treatment intensification. Clinical trials incorporating TB are needed to validate its prognostic impact.

Complete and long-lasting response to immunotherapy: A case report of urothelial cancer

INTRODUCTION

Bladder cancer is the tenth most common cancer worldwide, with Europe having the highest incidence rates. Regarding the treatment of metastatic disease, first-line treatment for fit patients is cisplatin-containing combination chemotherapy. However, a significant percentage of patients are ineligible for platinum-based chemotherapy, or progress under these regimens. Recently, immune checkpoint blockade has become a treatment option for this group of patients. In this report, we present the case of a male patient diagnosed with metastatic bladder cancer who did not tolerate cisplatin-containing chemotherapy and achieved complete response after treatment with pembrolizumab.

PATIENT CONCERNS

A 58 years-old Caucasian man with a medical history of high-grade urothelial carcinoma pT3bN0R0 under a watchful waiting strategy for 6 months presented to the Medical Oncology appointment with two axillary and cervical adenopathies.

DIAGNOSIS

Cervicothoracoabdominal computed tomography confirmed the presence of two large necrotic lymphadenopathies in the cervical and axillary lymphatic chains, and bone scintigraphy revealed dorsal (D11) and lumbar (L5) metastatic lesions. Ultrasonography-guided biopsy of the axillary nodule revealed the presence of metastatic tissue of primary urothelial origin.

INTERVENTIONS

The patient was initiated on a palliative chemotherapy regimen of carboplatin area under the curve 5 plus gemcitabine (1000 mg/m2). During the first cycle of chemotherapy, acute kidney failure akin 2 developed due to nonobstructive toxic acute tubular necrosis with progressive deterioration of kidney function. Therefore, palliative chemotherapy with carboplatin plus gemcitabine was changed to 200 mg of pembrolizumab every 21 days.

OUTCOMES

Overal survival of 57 months with an immune complete response according to the immune Response Evaluation Criteria in Solid Tumours criteria and an excellent quality of life.

CONCLUSION

This case illustrates that second-line therapy with ICIs (pembrolizumab or atezolizumab) has favourable results in achieving an immune complete response after intolerance to cisplatin-based regimens. ICIs provide durable responses that improve overall survival and quality of life.

Clinical relevance of receptor conversion in metastatic breast cancer: Case report

INTRODUCTION

Breast cancer comprises several different pathological entities defined by the presence or absence of hormonal receptors and human epidermal growth factor receptor 2 (HER2). During the disease course, the increase in tumor heterogeneity contributes to the discordant expression of estrogen/progesterone receptors and HER2 status between primary and metastatic lesions. We describe a case that demonstrates the clinical relevance of molecular reassessment during metastatic breast cancer progression.

PATIENT CONCERNS

A 40-year-old Caucasian woman with germline breast cancer gene mutation was referred to a general surgery appointment after breast ultrasound revealed a suspicious nodular lesion in 2012.

DIAGNOSIS

Ultrasound-guided microbiopsy revealed an invasive ductal carcinoma of no special type, hormone receptor-positive, and HER2-negative.

INTERVENTIONS

The patient underwent modified radical left mastectomy, adjuvant radiotherapy, chemotherapy, and endocrine therapy. Four years after the diagnosis, HER2 positive lung progression was documented, and the patient received anti-HER2 targeted systemic therapy for 15 months. New disease progression with a triple-negative profile was found, and palliative systemic treatment was changed to carboplatin for 3 months until new progression. Based on the results of the OlympiAD trial, monotherapy with Olaparib 300 mg twice daily for 28 days was initiated.

OUTCOMES

After seven cycles of treatment, patient showed progressive improvement in quality of life and maintained stable disease without significant adverse events.

CONCLUSION

The clinical relevance of hormone receptor and HER2 status discordance between primary tumors and metastatic lesions has been studied in recent years. This case report illustrates the clinical impact of molecular changes during disease progression and the adaptation of treatment options. This allows for an increase in both survival and quality of life in patients with metastatic breast cancer.

Rectal mixed adenoneuroendocrine carcinoma: Case report

RATIONALE

Colorectal mixed neuroendocrine-nonneuroendocrine neoplasms constitute a rare group of gastrointestinal tumors composed by both neuroendocrine and nonneuroendocrine components. Nondiagnostic macroscopic features, specific histological features, and poor awareness of the disease are responsible for the underestimated incidence and conflicting data available. Due to lack of randomized clinical trials and validated clinical guidelines, diagnostic and therapeutic approach are based on the standard of care for pure colorectal neuroendocrine carcinomas or adenocarcinomas.

PATIENT CONCERNS

A 76-year-old caucasian male, without relevant medical or familial history, presented a positive faecal occult blood test during colorectal cancer screening.

DIAGNOSIS

Total colonoscopy identified a rectal lesion with biopsy showing a moderate rectal adenocarcinoma staged as cT2N0M0.

INTERVENTIONS

Anterior resection of the rectum with right ileostomy followed by local radiotherapy with radio-sensitising chemotherapy and adjuvant chemotherapy with capecitabine 1000 mg bid plus oxaliplatin 130 mg/m2. Due to chronic nodular pulmonary aspergillosis and chemotherapy induced immunosuppression patient was on 400 mg/daily of oral voriconazole.

OUTCOMES

Overall survival of 15 months after progression under first line treatment and under palliative chemotherapy with platinum plus etoposide regimen.

LESSONS

The reported case illustrates the challenge associated to the management of mixed neuroendocrine-nonneuroendocrine carcinomas due to lack of validated guidelines and scientific evidence. From diagnosis and staging to treatment, all steps must be tailored to individual clinical and histological features.

The importance of remnant native vegetation of Amazonian submontane forest for the conservation of lizards

Forest fragmentation affects animal population dynamics mainly by loss of habitat and disruption of animal movement. Lizard assemblages are affected by environmental changes, but, depending on their ecological needs, some species might be more vulnerable than others. The southern Amazon suffers accelerated anthropic actions replacing natural environments by farmland (crops and pasture). This region is considerably drier than most of the northern Amazon, with stational semi-deciduous forests fragmented and isolated by pasture, and crops to a lesser extent. Here we report data on lizard assemblages using semi-deciduous forests, forest edge and the surrounding pasture in the southern Amazon in Mato Grosso, Brazil. Lizards were collected in 21 forest fragments (41 to 7,035 ha) surrounded by pasture; using pitfall traps placed on a degradation gradient - from pasture inwards forest fragment (up to 200 m). We collected 242 individuals (14 species, seven families) in 6,300 trap-days. The pattern of species occurrence was largely nested and this nesting was associated with three habitat guilds (generalist, edge-tolerant, and forest species). Although there was no obvious fragmentation effect on lizards diversity community-wise, Hoplocercus spinosus, Bachia dorbignyi, Micrablepharus maximiliani and Kentropyx calcarta were more vulnerable to such effects than all other ten species collected. We verified that assemblages inhabiting pasture and forest edge are a nested subset of assemblages from the forest core. The remnant native vegetation is not distributed homogeneously and lizards species can persist in different parts of the landscape, therefore we recommend the protection of forest remnants as an important conservation action for lizards of the southern Amazon.

The effect of coolants on the performance of magnetic micro-refrigerators

Magnetic refrigeration is an alternative cooling technique with envisaged technological applications on micro- and opto-electronic devices. Here, we present a magnetic micro-refrigerator cooling device with embedded micro-channels and based on the magnetocaloric effect. We studied the influence of the coolant fluid in the refrigeration process by numerically simulating the heat transfer processes using the finite element method. This allowed us to calculate the cooling power of the device. Our results show that gallium is the most efficient coolant fluid and, when used with Gd5Si2Ge2, a maximum power of 11.2 W/mm3 at a working frequency of -5 kHz can be reached. However, for operation frequencies around 50 Hz, water is the most efficient fluid with a cooling power of 0.137 W/mm3.

Abstract P2-12-04: Music Therapy Reduces Radiotherapy-Induced Fatigue in Patients with Breast or Gynecological Cancer: A Randomized Trial

BACKGROUND: Fatigue is a frequent side effect of radiotherapy, and may interfere with self-esteem, social activities, and quality of life. The authors investigated the influence of music therapy (MT) on the reduction of fatigue in women with breast or gynecological malignant neoplasia during radiotherapy.

METHODS: Randomized controlled trial (control group-CG and music therapy group-MTG) to assess fatigue, quality of life using the Functional Assessment of Cancer Therapy (FACT-F and FACT-G) version 4 and symptoms of depression using Beck Depression Inventory (BDI) in women undergoing radiotherapy in three distinct moments (during the first and the last week of radiotherapy, and on the week of the intermediary phase). Individual 30–40 minute sessions of music therapy were offered to participants of the MTG.

RESULTS: In this study, 164 women were randomized and 116 (63 CG and 53 MTG) were included in the analyses, with mean age of 52.9 years (CG) and 51.85 years (MTG). Participants in the MTG had an average of 10 MT sessions, during the study. FACT-F results were significant regarding Trial Outcome Index (TOI), synthesis of the Physical and functional well-being areas of FACT-F (p = 0.011), FACT-G (p = 0.005), FACT-F (p = 0.001) for MTG compared with CG. The depressive symptons were reduced to the minimum levels in the MTG (p = 0,005) with risk reduction of 74% (RR = 0,26; CI 0,10–0,70).

Stereotactic subthalamic nucleus lesioning for the treatment of Parkinson's disease

This study was performed to evaluate the effectiveness and safety of unilateral STN lesioning in 23 patients with PD. L-Dopa intake and dyskinesia, Hoehn & Yahr, Schwab & England, and UPDRS motor scores were recorded pre- and postoperatively. Stereotactic MRI and CT and macrostimulation were used to establish target coordinates. A single RF lesion was performed. All patients underwent postoperative MRI. Contralateral tremor arrest and decrease of rigidity and bradykinesia should be regarded as hallmarks to STN stimulation. All recorded parameters were significantly improved after a mean follow-up of 13.5 months. Patients with STN lateral territory lesioning (alpha <0.05), younger than 61 years and with a duration of the disease between 6 and 9 years (alpha >0.05) did better than the others. The recurrence rate was 10%. Two patients developed dyskinesias which were completely resolved by a Vim/VOp lesion. Other significant complications were rare. The authors conclude that unilateral STN lesioning is a safe and very effective procedure to treat PD.

Synthesis and biological evaluation of analogues of bacterial lipid I

Bacterial Lipid I analogues containing different anomeric groups at the muramic acid moiety were synthesized and screened in MurG enzyme assays run in the presence and absence of cell wall membranes. The results obtained in this study help elucidate the role of the lipid diphosphate in the recognition of Lipid I by MurG.

Recent developments in solid- and solution-phase methods for generating carbohydrate libraries

Carbohydrates and glycoconjugates have attracted a great deal of attention in recent years because of the key roles they play in biological processes. The development of carbohydrate-based libraries is a crucial step towards investigating the details of carbohydrate-mediated interactions, exploring the molecular diversity intrinsic to carbohydrates and identifying novel therapeutically interesting carbohydrate-containing drugs. This review describes recent advancements in solid- and solution-phase methods that relate to the generation of carbohydrate and glycoconjugate libraries. Special attention will be dedicated to the increasing use of carbohydrates as molecular scaffolds for library synthesis.

Gemcitabine 5'-triphosphate is a stoichiometric mechanism-based inhibitor of Lactobacillus leichmannii ribonucleoside triphosphate reductase: evidence for thiyl radical-mediated nucleotide radical formation

Ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii utilizes adenosylcobalamin and catalyzes the conversion of nucleoside triphosphates to deoxynucleoside triphosphates. One equivalent of 2',2'-difluoro-2'-deoxycytidine 5'-triphosphate, F2dCTP, rapidly inactivates RTPR. Analysis of the reaction products reveals that inactivation is accompanied by release of two fluoride ions and 0.84 equiv of 5'-deoxyadenosine and attachment of 1 equiv of corrin covalently to an active-site cysteine residue of RTPR. No cytosine release was detected. Proteolysis of corrin-labeled RTPR with endoproteinase Glu-C and peptide mapping at pH 5.8 revealed that C419 was predominantly modified. The kinetics of the inactivation have been examined by stopped-flow (SF) UV-vis spectroscopy and rapid freeze quench (RFQ) electron paramagnetic resonance (EPR) spectroscopy. Monitoring DeltaA525 nm shows that cob(II)alamin is formed with an apparent kobs of 50 s-1, only 2. 5-fold slower than a similar experiment carried out with cytidine 5'-triphosphate (CTP). The same reaction mixture was thus quenched at times from 22 ms to 30 s and examined by EPR spectroscopy. At early time points the EPR spectrum resembled a thiyl radical exchange coupled to cob(II)alamin. From 22 to 255 ms the total spin concentration remained unchanged at 1.4 spins/RTPR, twice that predicted by the amount of cob(II)alamin determined by SF. However, with time the signal attributed to the thiyl radical-cob(II)alamin disappears and new signal(s) with broad feature(s) at g = 2.33 and a sharp feature at g = 2.00 appeared, suggesting formation of cob(II)alamin and a nucleotide-based radical with only dipolar interactions. These studies have been interpreted to support the proposal that an RTPR-based thiyl radical can give rise to a nucleotide-based radical.

Inactivation of ribonucleotide reductase by (E)-2'-fluoromethylene-2'-deoxycytidine 5'-diphosphate: a paradigm for nucleotide mechanism-based inhibitors

Ribonucleotide reductase (RDPR) from Escherichia coli catalyzes the conversion of nucleotides to deoxynucleotides and is composed of two homodimeric subunits: R1 and R2. (E)- and (Z)-2'-fluoromethylene-2'-deoxycytidine 5'-diphosphate (FMCDP) are time dependent inactivators of this protein, with approximately 1.5 equiv being sufficient for complete loss of catalytic activity. Inactivation results from loss of the essential tyrosyl radical on R2 and alkylation of R1. Studies using electron spin resonance spectroscopy reveal that tyrosyl radical loss is accompanied by formation of a new, substrate-based radical. Experiments using [6'-14C]-(E)-FMCDP and [5-3H]-(E)-FMCDP reveal that alkylation of R1 is accompanied by release of 0.5 equiv of cytosine and 1.4 equiv of fluoride ion. When R1 is denatured subsequent to inactivation, approximately 1 equiv of label per R1 is observed only in studies carried out with [14C]FMCDP. Under these same conditions with [3H]FMCDP, 1.5 equiv of radiolabel is detected as cytosine. Inactivation of R1 thus results from alkylation by the sugar moiety of FMCDP. While studies to isolate the alkylated amino acid on R1 were unsuccessful, studies using a variety of site-directed mutants of R1 (C462S, C225S, C754/759S, C439S, and E441Q) indicate that E441 or possibly C439 is the modified residue. Inactivation is accompanied by rapid formation of a new chromophore with a lambda max at 334 nm. Dithiothreitol does not protect the enzyme against inactivation by FMCDP, although it does prevent chromophore formation. Two possible mechanisms are proposed to accommodate these experimental observations.

Use of triethylene glycol to mimic oligosaccharides: design and synthesis of a ligand based on chromomycin A3

Chromomycin A3 (CRA3) is an antitumor antibiotic that binds to DNA. It contains an acac-like metal binding site and forms a 2:1 complex with Mg2+. Interestingly, acac ligands similar to CRA3 form 1:1 complexes with Mg2+. We have previously shown that the unusual stability of the 2:1 CRA3-Mg2+ complex is related to a favorable intermolecular interaction between the CDE trisaccharide of one CRA3 molecule and the chromophore of the other. We have used this knowledge to design and synthesize a very simple molecule in which a triethylene glycol chain mimics the CDE trisaccharide of CRA3. This minimalist ligand behaves like CRA3 with respect to dimer formation. This result sheds light on how the CRA3 sugars function to stabilize the dimer. At the same time, the work provides a starting point for investigating the relationship between dimer formation and DNA binding. Starting from these relatively simple metal complexes, it should be possible to develop a better understanding of the structural requirements for DNA binding by CRA3 and related molecules.

The sugars in chromomycin A3 stabilize the Mg(2+)-dimer complex

Chromomycin A3 (CRA3) is a glycosylated antitumor antibiotic that binds as a dimer to the minor groove of DNA, with a Mg2+ cation (or another divalent cation with a radius less than 0.85 A) forming the center of the dimer. It has been shown that the chromose sugars are necessary for DNA binding [Kaziro & Kamiyama (1967) J. Biochem. (Tokyo) 62, 424-429; Kamiyama (1968) J. Biochem. (Tokyo) 63, 566-572], although the reason for this has not been addressed. We have investigated the role that the chromose sugars play in metal complexation in solution (methanol) by comparing the optical behavior of CRA3 and its aglycon, CRN, in the presence of various divalent metals (Mg2+, Ni2+, and Ca2+). The results show that CRA3 forms a dimeric complex [i.e., (CRA3)2M, where M is a metal ion] in the presence of 1 mol equiv of either Ni2+ or Mg2+ but a 1:1 complex in the presence of the much larger Ca2+. In contrast, CRN forms a 1:1 complex (CRN.M)+ with all three metals under identical conditions (1:1 mole ratio of drug to metal). Thus, for the smaller metal ions the sugars stabilize the 2:1 CRA3-metal complex in solution. NMR data on the 2:1 CRA3-Mg2+ complex show that the trisaccharide of one CRA3 molecule lies in close proximity to the chromophore of the other CRA3 molecule. This interaction, which is also present in the Mg(2+)-CRA3-DNA complex [Gao & Patel (1989) Biochemistry 28, 751-762], appears to be related to the stability of the dimer in solution.(ABSTRACT TRUNCATED AT 250 WORDS)