In vitro models to evaluate multidrug resistance in cancer cells: Biochemical and morphological techniques and pharmacological strategies.

The overexpression of ATP-binding cassette (ABC) transporters contributes to the failure of chemotherapies and symbolizes a great challenge in oncology, associated with the adaptation of tumor cells to anticancer drugs such that these transporters become less effective, a mechanism known as multidrug resistance (MDR). The aim of this review is to present the most widely used methodologies for induction and comprehension of in vitro models for detection of multidrug-resistant (MDR) modulators or inhibitors, including biochemical and morphological techniques for chemosensitivity studies. The overexpression of MDR proteins, predominantly, the subfamily glycoprotein-1 (P-gp or ABCB1) multidrug resistance, multidrug resistance-associated protein 1 (MRP1 or ABCCC1), multidrug resistance-associated protein 2 (MRP2 or ABCC2) and cancer resistance protein (ABCG2), in chemotherapy-exposed cancer lines have been established/investigated by several techniques. Amongst these techniques, the most used are (i) colorimetric/fluorescent indirect bioassays, (ii) rhodamine and efflux analysis, (iii) release of 3,30-diethyloxacarbocyanine iodide by fluorescence microscopy and flow cytometry to measure P-gp function and other ABC transporters, (iv) exclusion of calcein-acetoxymethylester, (v) ATPase assays to distinguish types of interaction with ABC transporters, (vi) morphology to detail phenotypic characteristics in transformed cells, (vii) molecular testing of resistance-related proteins (RT-qPCR) and (viii) 2D and 3D models, (ix) organoids, and (x) microfluidic technology. Then, in vitro models for detecting chemotherapy MDR cells to assess innovative therapies to modulate or inhibit tumor cell growth and overcome clinical resistance. It is noteworthy that different therapies including anti-miRNAs, antibody-drug conjugates (to natural products), and epigenetic modifications were also considered as promising alternatives, since currently no anti-MDR therapies are able to improve patient quality of life. Therefore, there is also urgency for new clinical markers of resistance to more reliably reflect in vivo effectiveness of novel antitumor drugs.

Comparación de la mortalidad en pacientes en quimioterapia o inmunoterapia durante y antes de la pandemia de COVID-19. Estudio multicéntrico de cohortes emparejadas en Argentina / Comparison of mortality in patients on chemotherapy or immunotherapy during and before COVID-19 pandemic. Multicenter matched cohort study in Argentina

RESUMEN Objetivos. Comparar la mortalidad por todas las causas de pacientes oncológicos no vacunados que recibieron quimioterapia o inmunoterapia durante la pandemia, con aquellos tratados antes de la pandemia. Materiales y métodos. Realizamos un estudio de cohortes en cuatro hospitales terciarios en Argentina. Pacientes ambulatorios con una neoplasia sólida de cualquier estadio en tratamiento citotóxico o inmune intravenoso fueron elegibles. La cohorte pandémica se enroló durante la fase inicial del brote y se comparó con una cohorte de un período anterior a la pandemia utilizando emparejamiento por puntuación de propensión (PSM, por sus siglas en inglés). Los sujetos se emparejaron por edad, sexo, seguro de salud, factores de riesgo para complicaciones graves por COVID-19, estado funcional, tipo de cáncer y tratamiento, línea de tratamiento e índice de masa corporal. La mortalidad por todas las causas se estimó en ambas cohortes después de seis meses de seguimiento. Resultados. 169 pacientes fueron reclutados entre abril y agosto de 2020 para la cohorte pandémica y 377 para la cohorte prepandémica en el mismo período de 2019, 168 pacientes fueron emparejados. Luego de la PSM, la mortalidad por todas las causas fue del 17,9% en la cohorte pandémica y del 18,5% en la cohorte prepandémica, Riesgo Relativo: 0,97 (intervalo de confianza al 95 %: 0,61-1,52; p=0,888). En la cohorte pandémica, 30/168 pacientes fallecieron, ninguno por infección por COVID-19. Conclusiones. No hemos observado un aumento de mortalidad en pacientes ambulatorios no vacunados en tratamiento oncológico endovenoso activo durante la pandemia por COVID-19.

ABSTRACT Objectives. To compare all-cause mortality of unvaccinated oncology patients who received chemotherapy or immunotherapy during the pandemic with those treated before the pandemic. Materials and methods. We conducted a cohort study in four tertiary hospitals in Argentina. Outpatients with a solid neoplasm of any stage under-going cytotoxic or intravenous immunotherapy were eligible. The pandemic cohort was enrolled during the initial phase of the outbreak and compared with a pre-pandemic cohort using propensity score matching (PSM). Subjects were matched for age, sex, health insurance, risk factors for severe COVID-19 complications, performance status, cancer type and treatment, line of treatment, and body mass index. All-cause mortality was estimated for both cohorts after 6 months of follow-up. Results. A total of 169 patients were recruited between April and August 2020 for the pandemic cohort and 377 for the pre-pandemic cohort in the same months of 2019; 168 patients were matched. After PSM, all-cause mortality was 17.9% in the pandemic cohort and 18.5% in the pre-pandemic cohort; the Relative Risk was 0.97 (95 % confidence interval: 0.61-1.52; p=0.888). In the pandemic cohort, 30/168 patients died, but none from COVID-19. Conclusions. Our findings show that the mortality rate of unvaccinated ambulatory patients on active intravenous oncology treatment during the COVID-19 pandemic did not increase.

Prevention of Caries in Cancer Patients: A Systematic Review on the Effectiveness of Dental Materials.

This study aims to identify dental materials and their effectiveness in preventing caries in patients after chemotherapy and radiotherapy for the head and neck. The electronic search was performed in PubMed, Science Direct, Embase and Scopus. All 653 articles found passed through a double-blinded screening process. The exclusion of articles by reading titles and abstracts selected 16 articles for full reading, of which 4 were included into the study. A risk of bias analysis for non-randomized and randomized articles was performed using respectively the ROBINS I and ROB II tools. The data extraction suggested that the casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), in association with fluorine, is able to form harder surfaces compared to the control group, the intraoral fluoride-releasing system (IFRS) effectiveness is similar to the fluorine in gel and a mouthwash composed of natural enzymes (Oral7) did not demonstrate effectiveness in the prevention dental caries. New randomized controlled clinical trials are necessary to evaluate the effectiveness of prevention when applying dental materials in patients after treatment of head and neck cancer.

Reações adversas medicamentosas em pacientes em quimioterapia e estratégias de intervenções / Adverse drug reactions in chemotherapy patients and intervention strategies / Reacciones adversas a medicamentos en pacientes quimioterápicos y estrategias de intervención

A quimioterapia do câncer pode ocasionar reações adversas medicamentosas (RAM), podendo resultar de interações medicamentosas (IM) e impactar na adesão. O presente estudo relatou as RAM apresentadas por pacientes em quimioterapia (QT) e propôs estratégias de intervenções. Este trabalho foi aprovado em comité de ética (5.160.503), sendo incluídos 23 pacientes em quimioterapia (oral- VO e/ou endovenosa- EV) e todos foram entrevistados. Recebiam apenas o QTEV, 20 pacientes e 2 QTEV e VO, a maioria em tratamento paliativo (50%), predomínio de estadiamento IV, sendo as doenças mais presentes de pâncreas (27,3%), estômago (22,7%) e mama (18,2%) e esquema mais usado foi Carboplatina + Paclitaxel. As principais comorbidades foram diabetes e hipertensão arterial. As interações medicamentosas foram classificadas em graves (45%), moderadas (55%) e intencional (75%), sendo necessário introdução de medicamentos de suporte (61%). Houve RAM de maior gravidade, neutropenia, sendo necessário a suspensão temporária, e de menor gravidade náuseas. Houve um óbito relacionado a evolução de doença e, talvez, o tratamento possa ter contribuído. Ao final, foram feitas as intervenções para cada caso e validado o formulário para a consulta farmacêutica a pacientes oncológicos.

Cancer chemotherapy can cause adverse drug reactions (ADRs), which can result from drug interactions (IM) and impact adherence. The present study reported the ADRs presented by patients undergoing chemotherapy (CT) and proposed intervention strategies. This work was approved by the ethics committee (5,160,503), and 23 patients on chemotherapy (oral-VO and/or intravenous-IV) were included and all were interviewed. Only received CTIV, 20 patients and 2 CTIV and VO, most in palliative treatment (50%), predominance of stage IV, being the most common diseases of pancreas (27.3%), stomach (22.7%) and breast (18.2%) and the most used regimen was Carboplatin + Paclitaxel. The main comorbidities were diabetes and arterial hypertension. Drug interactions were classified as severe (45%), moderate (55%) and intentional (75%), requiring the introduction of supportive drugs (61%). There were more severe ADRs, neutropenia, requiring temporary suspension, and less severe nausea. There was one death related to the evolution of the disease and, perhaps, the treatment may have contributed. At the end, interventions were made for each case and the form for the pharmaceutical consultation to cancer patients was validated.

La quimioterapia contra el cáncer puede causar reacciones adversas a los medicamentos (RAM), que pueden ser consecuencia de interacciones farmacológicas (IM) y repercutir en la adherencia. El presente estudio reportó las RAM presentadas por pacientes en quimioterapia (QT) y propuso estrategias de intervención. Este trabajo fue aprobado en comité de ética (5.160.503), se incluyeron 23 pacientes en quimioterapia (oral- VO y/o endovenosa-EV) y todos fueron entrevistados. Recibieron sólo QTEV, 20 pacientes y 2 QTEV y VO, la mayoría en tratamiento paliativo (50%), predominio de estadiaje IV, siendo las enfermedades más presentes las de páncreas (27,3%), estómago (22,7%) y mama (18,2%) y el esquema más utilizado fue Carboplatino + Paclitaxel. Las principales comorbilidades fueron la diabetes y la hipertensión arterial. Las interacciones farmacológicas se clasificaron como graves (45%), moderadas (55%) e intencionadas (75%), requiriendo la introducción de fármacos de apoyo (61%). La RAM más grave fue la neutropenia, que requirió la suspensión temporal, y la menos grave las náuseas. Hubo una muerte relacionada con la evolución de la enfermedad y, tal vez, el tratamiento pudo haber contribuido. Al final, se realizaron intervenciones para cada caso y se validó el formulario de consulta farmacéutica a pacientes oncológicos.

Chemotherapy and Anticancer Drugs Adjustment in Obesity: A Narrative Review.

BACKGROUND: Obese individuals have higher rates of cancer incidence and cancer- related mortality. The worse chemotherapy outcomes observed in this subset of patients are multifactorial, including the altered physiology in obesity and its impact on pharmacokinetics, the possible increased risk of underdosing, and treatment-related toxicity. AIMS: The present review aimed to discuss recent data on physiology, providing just an overall perspective and pharmacokinetic alterations in obesity concerning chemotherapy. We also reviewed the controversies of dosing adjustment strategies in adult and pediatric patients, mainly addressing the use of actual total body weight and ideal body weight. METHODS: This narrative review tried to provide the best evidence to support antineoplastic drug dosing strategies in children, adolescents, and adults. RESULTS: Cardiovascular, hepatic, and renal alterations of obesity can affect the distribution, metabolism, and clearance of drugs. Anticancer drugs have a narrow therapeutic range, and variations in dosing may result in either toxicity or underdosing. Obese patients are underrepresented in clinical trials that focus on determining recommendations for chemotherapy dosing and administration in clinical practice. After considering associated comorbidities, the guidelines recommend that chemotherapy should be dosed according to body surface area (BSA) calculated with actual total body weight, not an estimate or ideal weight, especially when the intention of therapy is the cure. CONCLUSION: The actual total body weight dosing appears to be a better approach to dosing anticancer drugs in both adults and children when aiming for curative results, showing no difference in toxicity and no limitation in treatment outcomes compared to adjusted doses.

Importance of tumor size in resectable stage III-N2 non-small cell lung cancer.

OBJECTIVE: The 8th TNM edition classifies stage III-N2 disease as IIIA and IIIB based on a tumor size cutoff of 5 cm. However, the importance of tumor size on survival in patients with resectable stage III-N2 disease has not been analyzed systematically. METHODS: Survival analysis based on tumor size (>5 cm vs ≤ 5 cm) for 255 consecutive patients with nonbulky (maximal lymph node diameter of 1.5 cm) stage III-N2 non-small cell lung cancer treated with surgery in our institution. RESULTS: Ninety patients (35.3%) underwent induction chemoradiation therapy (n = 72, 28%) or induction chemotherapy (n = 18, 7%), and 165 patients underwent primary surgery followed by adjuvant chemotherapy (n = 52, 32%), adjuvant chemoradiation therapy (n = 47, 29%), or adjuvant radiation therapy (n = 14, 13.2%). After a median follow-up of 6.5 years, the overall survival was 46.5% at 5 years and 28.9% at 10 years. In tumors 5 cm or less, there was no difference in survival between patients treated with induction or adjuvant therapy. However, in tumors greater than 5 cm, the survival was significantly better after induction therapy compared with adjuvant therapy or surgery alone. Pathologic multi-station N2 disease was more frequently detected in tumors greater than 5 cm (31% vs 18% in tumors ≤5 cm, P = .042), and the rate of R1 resection was lower after induction therapy (2.2% vs 8.5% in primary surgery, P = .048). CONCLUSIONS: These results support the redefinition of tumors greater than 5 cm with resectable N2 disease to stage IIIB. This change should help to refine the multimodality approach for stage III-N2 lung cancer.

Coumarin derivative 7-isopentenyloxycoumarin induces in vivo antitumor activity by inhibit angiogenesis via CCL2 chemokine decrease.

Cancer is one of the most urgent problems in medicine. In recent years, cancer is the second leading cause of death globally. In search for more effective and less toxic treatment against cancer, natural products are used as prototypes in the synthesis of new anticancer drugs. The aim of this study was to investigate the in vivo toxicity and the mechanism of antitumor action of 7-isopentenyloxycoumarin (UMB-07), a coumarin derivative with antitumor activity. The toxicity was evaluated in vitro (hemolysis assay), and in vivo (micronucleus and acute toxicity assays). Ehrlich ascites carcinoma model was used to evaluate in vivo antitumor activity of UMB-07 (12.5, 25, or 50 mg/kg, intraperitoneally, i.p.), after 9 days of treatment, as well as toxicity. UMB-07 (2000 µg/mL) induced only 0.8% of hemolysis in peripheral blood erythrocytes of mice. On acute toxicity assay, LD50 (50% lethal dose) was estimated at around 1000 mg/kg (i.p.), and no micronucleated erythrocytes were recorded after UMB-07 (300 mg/kg, i.p.) treatment. UMB-07 (25 and 50 mg/kg) reduced tumor volume and total viable cancer cells. In the mechanism action investigation, no changes were observed on the cell cycle analysis; however, UMB-07 reduced peritumoral microvessels density and CCL2 chemokine levels. In addition, UMB-07 showed weak toxicity on biochemical, hematological, and histological parameters after 9 days of antitumor treatment. The current findings suggest that UMB-07 has low toxicity and exerts antitumor effect by inhibit angiogenesis via CCL2 chemokine decrease.

Co-Loaded Curcumin and Methotrexate Nanocapsules Enhance Cytotoxicity against Non-Small-Cell Lung Cancer Cells.

Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (-33 to -41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer.

Provider delay in treatment initiation and its influence on survival outcomes in women with operable breast cancer.

AIM: The goal of this study was to determine whether a delay in starting treatment via surgery or neoadjuvant chemotherapy is related to a decrease in cancer-specific survival (CSS) in women with operable breast cancer (BrCr). BACKGROUND: Limited medical infrastructure and a lack of cancer prevention awareness in low- and middle-income countries have caused high BrCr incidence and mortality rates. METHODS: We analyzed a retrospective cohort of 720 women treated at a single center from 2005 to 2012. CSS estimates were obtained by the Kaplan-Meier method. A Cox model of proportional risks was performed to obtain the risk of dying from BrCr. We also obtained the risk according to the category of treatment initiation. RESULTS: Women with locally advanced stages and without hormone receptor expression were more likely to initiate treatment after 45 days. Patients in Stage IIIA had a 78.1% survival if treatment was initiated before 45 days (95% CI, 0.70-0.84) and 63.6% survival if treatment was started after 45 days (95% CI, 0.44-0.78; p < 0.001). Patients in Stage IIIB had a 62.9% survival if treatment was initiated before 45 days (95% CI, 0.53-0.72) and 57.4% survival if treatment started after 45 days (95% CI, 0.31-0.89; p < 0.001). Prognostic factors in which lower survival was recognized were Stage IIIA, Stage IIIB, treatment initiation after 45 days, and triple-negative tumors. CONCLUSIONS: The initiation of treatment within the first 45 days of diagnosis of BrCr in women portends better survival compared with those who began treatment longer than 45 days from diagnosis.

Post-marketing assessment of generic tamoxifen in Brazilian breast cancer patients.

Generic formulations of tamoxifen are commonly prescribed to oestrogen receptor-positive breast cancer patients at the Brazilian National Cancer Institute (INCA). We carried out a post-marketing surveillance of the generic tamoxifen formulation in current use at INCA, by comparing plasma concentrations of the parent drug and metabolites obtained with the generic vs the reference formulation. Thirty patients participated in an open-label, bracketed protocol, comprising 3 successive phases of 30-32 days each: the generic formulation was used in phases 1 and 3 and the reference formulation in phase 2. Two blood samples were collected in the last 4 days of each phase, for LC-MS/MS quantification of tamoxifen and metabolites in plasma. The median plasma concentrations (ng/mL) for the reference formulation were as follows: tamoxifen, 135.0 (CI 95% 114.2-155.8); endoxifen, 35.3 (30.0-40.8); and 4-hydroxytamoxifen, 4.8 (4.2-5.4). The endoxifen/tamoxifen plasma concentration ratio was 0.27 (0.21-0.25). ANOVA detected no statistically significant difference in plasma concentrations of tamoxifen, metabolites or the endoxifen/tamoxifen ratio among the three phases. The genetic component (rGC) of the CYP2D6-mediated conversion of tamoxifen into endoxifen, estimated using the repeated drug administration procedure across the three phases, was 0.87, pointing to an important component of genetic variability. In conclusion, this first post-marketing surveillance trial of oncologic generic drugs carried out in Brazilian patients verified the switchability between the reference and the generic tamoxifen formulation currently used at our institution. The adopted bracketed protocol adds confidence to this conclusion and may serve as a frame for future trials of post-marketing assessment of other generic drug products.

Cáncer, quimioterapia y un corazón roto. Reporte de un caso de cardiomiopatía de Takotsubo asociada a quimioterapia / Chemotherapy, cancer, and broken heart. Case report of cardiomyopathy takotsubo linked chemotheraphy

Introducción: El nexo entre quimioterapia y Cardiomiopatía de Takotsubo es cada vez más reconocido en años recientes, pero aunque la causalidad está establecida, los reportes aún son escasos, la cantidad de fármacos relacionados es creciente y los mecanismos de acción no están completamente dilucidados. Reporte de caso: Se presenta el caso de una paciente con Mieloma Múltiple que luego de una sesión de quimioterapia con Ciclofosfamida y Talidomida, desarrolla de forma súbita un cuadro compatible con síndrome coronario agudo; fue sometida a una angiocoronariografía que mostró arterias coronarias sin lesiones significativas, y balonamiento apical, hallazgos consistentes con Cardiomiopatía de Takotsubo. Conclusiones: La Miocardiopatía de Takotsubo puede representar una forma de disfunción cardiaca dentro del espectro de la cardiotoxicidad inducida por quimioterapia, que difiere de la forma más común que es la toxicidad por dosis acumulada. Dada la cantidad creciente de casos reportados, incluso la presencia de recidiva tras la re administración del mismo agente quimioterápico, deben identificarse adecuadamente los implicados y evitar su uso en pacientes de alto riesgo.(AU)

Introduction: The link between chemotherapy and Takotsubo cardiomyopathy has become increasingly recognized in recent years, although causality remains to be established and the mechanism of action is not yet fully understood. Case Report: Here we present the case of a patient with Multiple Myeloma, that after of cytotoxic treatment with cyclophosphamide and thalidomide, developed coronary acute syndrome. She went onto have coronary angiography that demonstrated unobstructed coronary arteries and Apical ballooning, consistent with Takotsubo C a r d i o m y o p a t h y. C o n c l u s i o n : Ta k o t s u b o cardiomyopathy may represent a form of cardiac dysfunction within the spectrum of chemotherapy￾induced cardiac toxicity that differs from the more common cumulative-dosing toxicity. Given the increasing amount of case report, and the presence of recurrence after the re administration from the same chemotherapy agent; must be properly identified and avoid its use in high risk patient.(AU)

In vitro study of Withanolide D toxicity on goat preantral follicles and its effects on the cell cycle.

The Withanolide D is a chemotherapeutic potential against the human tumor cell. However, there is no report on the effect of this compound on ovarian function, especially on preantral folliculogenesis. The aim of this study was to evaluate the toxicity of a new candidate to anticancer drug, Withanolide D (WD) on morphologic integrity, development (activation and granulosa cell proliferation) and gene expression of ABCB1 protein of caprine preantral follicles. Ovarian fragments were cultured in vitro for 2 or 6 days in α-MEM or α-MEM added with paclitaxel (PTX -0.1 µg/mL; negative control) and different concentrations of WD (WD1.5, WD3.0 or WD6.0). The higher dose of WD showed a toxic effect similar to PTX and higher (P < 0.05) than other treatments after 2 and 6 days. In addition, WD6.0 reduced the cell proliferating compared to PTX or mild dose. The expression of ABCB1 remained unchanged in the presence of the chemotherapeutic agents (PTX and WD) throughout the culture period. In conclusion, WD exerted a toxic effect observed by decreasing follicular survival and cell proliferation, on the preantral caprine follicles similar to PTX, whose negative effect on folliculogenesis is already widely known.

Amifostine reduces inflammation and protects against 5-fluorouracil-induced oral mucositis and hyposalivation

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) tissue levels, and positive immunostaining for TNF-α, IL-1β, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.

Analysis of time interval between breast cancer diagnosis and treatment / Análise do tempo decorrido entre diagnóstico e tratamento do câncer de mama

Introduction: Breast cancer has a good prognosis when treated early. However, the mortality rate in Brazil is still high. The time interval between radiological suspicion and diagnosis/treatment impacts the survival. Methods: This is a retrospective crosssectional study that assessed patients treated at a reference center, with abnormal breast imaging findings and subsequent confirmation of breast cancer, from January 2011 to June 2015. We reviewed variables related to the dates of the abnormal test result, first mastology appointment, biopsy, surgery, and the start of chemotherapy ­ when indicated. Time intervals were compared using the Friedman and Kruskal-Wallis tests with the software SPSS® 23.0. Results: We analyzed 65 patients. The median time between the abnormal test result and first mastology appointment was 35 days; between first mastology appointment and biopsy, 31 days; between biopsy and surgery, 85 days; and between surgery and chemotherapy, 137 days. The last two intervals showed significant differences (p<0.001). Discussion: Breast cancer patients had a significant delay until surgery and the start of chemotherapy. Early integration of the multidisciplinary team involved in this process and internal audits are necessary to optimize time intervals.

Introdução: O câncer de mama apresenta bom prognóstico quando tratado precocemente, entretanto, a mortalidade no Brasil continua elevada. O tempo entre suspeita radiológica e diagnóstico e tratamento tem impacto na sobrevida. Métodos: Foi realizado um estudo transversal e retrospectivo que avaliou pacientes atendidas em centro de referência com imagem mamária alterada e posterior confirmação de câncer de mama de janeiro de 2011 a junho e 2015. Foram revisadas variáveis relacionadas às datas do exame alterado, da primeira consulta, da biópsia, da cirurgia e do início da quimioterapia, quando indicada. Os intervalos de tempo foram comparados pelos testes Friedman e Kruskal-Wallis, pelo programa SPSS® 23.0. Resultados: Foram analisadas 65 pacientes. A mediana de tempo entre exame alterado e primeira consulta foi 35 dias, entre consulta na mastologia e biópsia foi 31 dias, entre biópsia e cirurgia foi 85 dias e entre cirurgia e quimioterapia foi 137 dias. Foram observadas diferenças significativas nos dois últimos intervalos (p<0,001). Discussão: As pacientes com câncer de mama apresentaram atraso significativo até a cirurgia e até o início da quimioterapia. Há necessidade da integração precoce da equipe multidisciplinar implicada nesse processo e auditorias internas a fim de otimizar os intervalos de tempo

Carboplatin as an alternative to Cisplatin in chemotherapies: New insights at single molecule level.

Here we report a new study performed at single molecule level on the interaction of the antineoplastic drug Carboplatin and the DNA molecule - the main target of the drug inside cells in cancer chemotherapies. By using optical tweezers, we measure how the mechanical properties of the DNA-Carboplatin complexes changes as a function of the drug concentration in the sample, for two different ionic strengths ([Na] = 150 mM and [Na] = 1 mM). From these measurements, the binding mechanism and the physicochemical (binding) parameters of the interaction were inferred and directly compared to those obtained for the precursor drug Cisplatin under equivalent conditions. As the main conclusion, we show that Carboplatin binds preferentially forming covalent monoadducts in contrast to Cisplatin, which is hydrolyzed easier and presents a higher efficiency in forming covalent diadducts along the double-helix. In addition, we explicitly show that Carboplatin is much less sensitive to ionic strength changes when compared to Cisplatin. These findings provide new insights on the interactions of platinum-based compounds with the DNA molecule, being important to improve the current treatments and in the development of new antineoplastic agents.

Dual effect of silymarin on experimental non-alcoholic steatohepatitis induced by irinotecan.

Irinotecan-based regimens are commonly used for treatment of colorectal cancer, which is limited by mucositis and non-alcoholic steatohepatitis (NASH). Silymarin (SIL) prevents fatty liver disease in the clinical setting and in models of liver damage induced chemically. This study investigated the possible effect of SIL on irinotecan (IRI)-induced NASH. Swiss female mice were injected with saline (SAL 5ml/kg i.p.), IRI (50mg/kg i.p.), SIL (150mg/kg p.o.) or IRI (50mg/kg i.p.)+(SIL 1.5, 15 or 150mg/kg p.o.) thrice/week/7weeks. On the seventh week, blood samples were collected for transaminases assay and livers were collected for histopathology, measurement of the total lipids, malondyadehyde (MDA), non-protein sulfhydryl groups (NPSH), cytokines (IL-1ß, IL 6 and IL-10), 3-nitrotyrosine (N-Tyr) and toll-like receptor 4 (TLR4) immunoexpression, quantification of NF-kB, α-smooth muscle actin (α-SMA), and Escherichia coli 16S rRNA gene (RRS) expression. IRI increased liver transaminases, neutrophil infiltration, lipid accumulation, MDA, IL-1ß and IL-6 levels, N-Tyr and TLR4 immunostaining, NF-kB, α-SMA expression and RRS versus the SAL group (p<0.05). Additionally, SIL (1.5mg/kg) improved these parameters (p<0.05), except neutrophil infiltration and RSS versus the IRI group. Furthermore, the SIL (15mg/kg) only improved the inflammatory parameters, the expression of α-SMA and RRS versus the IRI group (p<0.05). The higher dose of SIL (150mg/kg) was even more deleterious than the intermediate dose. Therefore, silymarin showed a dual effect on liver damage induced by IRI. Hepatoprotection seems to involve the inhibition of oxidative stress and protein nitrosylation, preventing activation of hepatic fibrosis mechanisms.

A glucose-targeted mixed micellar formulation outperforms Genexol in breast cancer cells.

Breast cancer represents the top cancer among women, accounting 521.000 deaths per year. Development of targeted nanomedicines to breast cancer tissues represents a milestone to reduce chemotherapy side effects. Taking advantage of the over-expression of glucose (Glu) membrane transporters in breast cancer cells, we aim to expand the potential of a paclitaxel (PTX)-loaded mixed micellar formulation based on polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer (Soluplus®) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) by its surface decoration with Glu moieties. The glycopolymer (Soluplus(Glu)) was obtained by microwave-assisted ring opening reaction of δ-gluconolactone initiated by Soluplus®. The glycosylation was confirmed by 1H NMR and by agglutination assays employing Concanavalin A. The hydrodynamic diameter of Soluplus(Glu) micelles was characterized by dynamic light scattering (100.3±3.8nm) as well as the critical micellar concentration value (0.0151% w/v). Then, a mixed micelle formulation employing Soluplus®, Soluplus(Glu) and TPGS (3:1:1wt ratio) loaded with PTX (4mg/mL) was developed as a multifunctional nanocarrier. Its in vitro anticancer performance in MCF-7 (1.6-fold) and MDA-MB-231 (14.1-fold) was significantly enhanced (p<0.05) versus the unique commercially available micellar-based PTX-nanoformulation (Genexol®). Furthermore, the in vitro PTX cellular uptake assays revealed that the drug intracellular/cell content was significantly (p<0.05) higher for the Glu-containing mixed micelles versus Genexol® after 6h of incubation with MCF-7 (30.5-fold) and MDA-MB-231 (5-fold). Overall, results confirmed the potential of our Glu-decorated mixed colloidal formulation as an intelligent nanocarrier for PTX-targeted breast cancer chemotherapy.

Pharmacokinetic/pharmacodynamic modeling of etoposide tumor growth inhibitory effect in Walker-256 tumor-bearing rat model using free intratumoral drug concentrations.

The purpose of this study was to establish a population pharmacokinetic/pharmacodynamic (PK/PD) model linking etoposide free tumor and total plasma concentrations to the inhibition of solid tumor growth in rats. Walker-256 tumor cells were inoculated subcutaneously in the right flank of Wistar rats, which were randomly divided in control and two treated groups that received etoposide 5 or 10mg/kg i.v. bolus every day for 8 and 4days, respectively, and tumor volume was monitored daily for 30days. The plasma and intratumoral concentrations-time profiles were obtained from a previous study and were modeled by a four-compartment population pharmacokinetic (popPK) model. PK/PD analysis was conducted using MONOLIX v.4.3.3 on average data and by mean of a nonlinear mixed-effect model. PK/PD data were analyzed using a modification of Simeoni Tumor Growth Inhibition (TGI) model by introduction of an Emax function to take into account the concentration dependency of k2variable parameter (variable potency). The Simeoni TGI-Emax model was capable to fit schedule-dependent antitumor effects using the tumor growth curves from the control and two different administered schedules. The PK/PD model was capable of describing the tumor growth inhibition using total plasma or free tumor concentrations, resulting in higher k2max (maximal potency) for free concentrations (25.8mL·µg-1·day-1 - intratumoral vs. 12.6mL·µg-1·day-1 total plasma). These findings indicate that the plasma concentration may not be a good surrogate for pharmacologically active free tumor concentrations, emphasizing the importance of knowing drug tumor penetration to choose the best antitumor therapy.

Irinotecan- and 5-fluorouracil-induced intestinal mucositis: insights into pathogenesis and therapeutic perspectives.

PURPOSE: Intestinal mucositis and diarrhea are common manifestations of anticancer regimens that include irinotecan, 5-fluorouracil (5-FU), and other cytotoxic drugs. These side effects negatively impact therapeutic outcomes and delay subsequent cycles of chemotherapy, resulting in dose reductions and treatment discontinuation. Here, we aimed to review the experimental evidence regarding possible new targets for the management of irinotecan- and 5-FU-related intestinal mucositis. METHODS: A literature search was performed using the PubMed and MEDLINE databases. No publication time limit was set for article inclusion. RESULTS: Here, we found that clinical management of intestinal mucositis and diarrhea is somewhat ineffective at reducing symptoms, possibly due to a lack of specific targets for modulation. We observed that IL-1ß contributes to the apoptosis of enterocytes in mucositis induced by 5-FU. However, 5-FU-related mucositis is far less thoroughly investigated with regard to specific molecular targets when compared to irinotecan-related disease. Several studies have proposed that a correlation exists between the intestinal microbiota, the enterohepatic recirculation of active metabolites of irinotecan, and the establishment of mucositis. However, as reviewed here, this association seems to be controversial. In addition, the pathogenesis of irinotecan-induced mucositis appears to be orchestrated by interleukin-1/Toll-like receptor family members, leading to epithelial cell apoptosis. CONCLUSIONS: IL-1ß, IL-18, and IL-33 and the receptors IL-1R, IL-18R, ST2, and TLR-2 are potential therapeutic targets that can be modulated to minimize anticancer agent-associated toxicity, optimize cancer treatment dosing, and improve clinical outcomes. In this context, the pathogenesis of mucositis caused by other anticancer agents should be further investigated.

Sialoganglioside Micelles for Enhanced Paclitaxel Solubility: In Vitro Characterization.

Efficiency of mono-sialogangliosides to load Paclitaxel (Ptx) has recently been found to depend on the structure of the polysaccharide chain. In this study, we demonstrated that incorporation of only one more sialic acid into the ganglioside molecule, independently of its position, causes a 4-fold increase in Ptx-loading capacity, the maximum being at a 5:1 molar ratio (di-sialoganglioside/Paclitaxel, GD/Ptx). These complexes are stable in solution for at least 3 months, and over 90% of Ptx remains loaded in the micelles after extreme stress conditions such as high-speed centrifugation, lyophilization, or freeze-thaw cycles. Ganglioside micelles protect 50% of the initially loaded Ptx from alkaline hydrolysis after 24 h at pH 10. Dynamic light scattering studies revealed that GD micelles increase their size from 9 to 12 nm when loaded with Ptx. Transmission electron microscopy shows a homogeneous population of spherical micelles either with or without Ptx. In vitro biological activity was similar to that of the free drug. These results provide further options of self-assembled nanostructures of di- and tri-sialogangliosides with a higher loading capacity.