Cavitation-on-a-Chip Enabled Size-Specific Liposomal Drugs for Selective Pharmacokinetics and Pharmacodynamics.

The size of liposomal drugs has been demonstrated to strongly correlate with their pharmacokinetics and pharmacodynamics. While the microfluidic method successfully achieves the production of liposomes with well-controlled sizes across various buffer/lipid flow rate ratio (FRR) settings, any adjustments to the FRR inevitably influence the concentration, encapsulation efficiency (EE), and stability of liposomal drugs. Here we describe a controllable cavitation-on-a-chip (CCC) strategy that facilitates the precise regulation of liposomal drug size at any desired FRR. The CCC-enabled size-specific liposomes exhibited striking differences in uptake and biodistribution behaviors, thereby demonstrating distinct antitumor efficacy in both tumor-bearing animal and melanoma patient-derived organoid (PDO) models. Intriguingly, as the liposome size decreased to approximately 80 nm, the preferential accumulation of liposomal drugs in the liver transitioned to a predominant enrichment in the kidneys. These findings underscore the considerable potential of our CCC approach in influencing the pharmacokinetics and pharmacodynamics of liposomal nanomedicines.

Mimicking Tumor Metastasis Using a Transwell-Integrated Organoids-On-a-Chip Platform.

The mortality rate among cancer patients is primarily attributed to tumor metastasis. The evaluation of metastasis potential provides a powerful framework for personalized therapies. However, little work has so far been undertaken to precisely model tumor metastasis in vitro, hindering the development of preventive and therapeutic interventions. In this work, a tumor-metastasis-mimicked Transwell-integrated organoids-on-a-chip platform (TOP) for precisely evaluating tumor metastatic potential is developed. Unlike the conventional Transwell device for detecting cell migration, the engineered device facilitates the assessment of metastasis in patient-derived organoids (PDO). Furthermore, a novel Transwell chamber with a hexagon-shaped structure is developed to mimic the migration of tumor cells into surrounding tissues, allowing for the evaluation of tumor metastasis in a horizontal direction. As a proof-of-concept demonstration, tumor organoids and metastatic clusters are further evaluated at the protein, genetic, and phenotypic levels. In addition, preliminary drug screening is undertaken to highlight the potential for using the device to combat cancers. In summary, the tumor-metastasis-mimicked TOP offers unique capabilities for evaluating the metastasis potential of tumor organoids and contributes to the development of personalized cancer therapies.

Fibrosis-4 index stratifies risks of hepatocellular carcinoma in patients with chronic hepatitis C.

BACKGROUND AND AIMS: Risk stratification for patients with a higher risk of hepatocellular carcinoma (HCC) is crucial. We aimed to investigate the role of the Fibrosis-4 (FIB-4) index in predicting chronic hepatitis C (CHC)-related HCC. METHODS: A retrospective cohort study consecutively included treatment-naive CHC patients receiving longitudinal follow-up at the National Taiwan University Hospital from 1986 to 2014. The clinical data were collected and traced for HCC development. Multivariable Cox proportional hazard regression analysis was used to investigate the predictors for HCC. RESULTS: A total of 1285 patients in the ERADICATE-C cohort were included. The median age was 54, 56% were females, and 933 had HCV viremia. There were 33%, 38%, and 29% of patients having FIB-4 index <1.45, 1.45-3.25, and ≥3.25, respectively. After a median of 9-year follow-up, 186 patients developed HCC. Multivariable analysis revealed that older age, AFP≥20 ng/mL, cirrhosis, and a higher FIB-4 index were independent predictors for HCC. Compared with patients with FIB-4 index <1.45, those with FIB-4 1.45-3.25 had a 5.51-fold risk (95% confidence interval [CI]: 2.65-11.46), and those with FIB-4 ≥ 3.25 had 7.45-fold risk (95% CI: 3.46-16.05) of HCC. In CHC patients without viremia, FIB-4 index 1.45-3.25 and FIB-4 ≥ 3.25 increased 6.78-fold and 16.77-fold risk of HCC, respectively, compared with those with FIB-4 < 1.45. CONCLUSION: The baseline FIB-4 index can stratify the risks of HCC in untreated CHC patients, even those without viremia. The FIB-4 index should thus be included in the management of CHC.

One-Step Formation of Targeted Liposomes in a Versatile Microfluidic Mixing Device.

Targeted liposomes, as a promising carrier, have received tremendous attention in COVID-19 vaccines, molecular imaging, and cancer treatment, due to their enhanced cellular uptake and payload accumulation at target sites. However, the conventional methods for preparing targeted liposomes still suffer from limitations, including complex operation, time-consuming, and poor reproducibility. Herein, a facile and scalable strategy is developed for one-step construction of targeted liposomes using a versatile microfluidic mixing device (MMD). The engineered MMD provides an advanced synthesis platform for multifunctional liposome with high production rate and controllability. To validate the method, a programmed death-ligand 1 (PD-L1)-targeting aptamer modified indocyanine green (ICG)-liposome (Apt-ICG@Lip) is successfully constructed via the MMD. ICG and the PD-L1-targeting aptamer are used as model drug and targeting moiety, respectively. The Apt-ICG@Lip has high encapsulation efficiency (89.9 ± 1.4%) and small mean diameter (129.16 ± 5.48 nm). In vivo studies (PD-L1-expressing tumor models) show that Apt-ICG@Lip can realize PD-L1 targeted photoacoustic imaging, fluorescence imaging, and photothermal therapy. To verify the versatility of this approach, various targeted liposomes with different functions are further prepared and investigated. These experimental results demonstrate that this method is concise, efficient, and scalable to prepare multifunctional targeted liposomal nanoplatforms for molecular imaging and disease theranostics.

Serial increase and high alpha-fetoprotein levels predict the development of hepatocellular carcinoma in 6 months.

AIM: Alpha-fetoprotein (AFP) checkup with abdominal ultrasonography for hepatocellular carcinoma (HCC) surveillance remains controversial. We evaluated a serial AFP-increase and high AFP levels in the prediction of HCC. METHODS: At-risk patients with chronic liver disease underwent HCC surveillance with trimonthly AFP measurement were included and categorized into HCC and non-HCC groups. Their AFP levels at 12, 9, and 6 months (-6M) before the outcome date were evaluated. Group-based trajectory analysis and multivariable regression analysis were performed to identify AFP trajectories as risk predictors for HCC. RESULTS: Overall, 2776 patients were included in the HCC (n = 326) and non-HCC (n = 2450) groups. Serial AFP levels were significantly higher in the HCC than the non-HCC groups. Trajectory analysis identified AFP-increase group (11%) increased 24-fold risks of HCC compared with the AFP-stable (89%) group. Compared with patients without the AFP-increase, a serial 3-month AFP-increase ≥10% elevated HCC risk by 12.1-fold (95% CI: 6.5-22.4) in 6 months, and the HCC risks increased 13-60 fold in patients with cirrhosis, hepatitis B, or C receiving antiviral therapy, or AFP levels <20 ng/ml. Combining serial AFP-increase ≥10% and AFP ≥20 ng/ml at -6M significantly increased 41.7-fold (95% CI: 13.8-126.2) HCC risks. In patients who underwent biannual AFP checkups, those with both 6-month AFP-increase ≥10% and AFP ≥20 ng/ml increased 22.1-fold (95% CI: 12.52-39.16) HCC risks in 6 months. Most HCCs were detected at an early stage. CONCLUSIONS: Serial 3-6-month AFP-increase of ≥10% previously and AFP level of ≥20 ng/ml significantly increased HCC risks in 6 months.

Serum PIVKA-II and alpha-fetoprotein at virological remission predicts hepatocellular carcinoma in chronic hepatitis B related cirrhosis.

BACKGROUND: The risk of hepatocellular carcinoma (HCC) is reduced but not eliminated after nucleos(t)ide analogue (NA) therapy in chronic hepatitis B (CHB). We aimed to investigate the role of serum Prothrombin Induced by Vitamin K Absence or Antagonist-II (PIVKA-II) and alpha-fetoprotein in predicting HCC and mortality in cirrhotic CHB patients at virological remission (VR) following NA therapy. METHODS: Patients with CHB-related cirrhosis undergoing NA therapy from two medical centers in Taiwan were retrospectively included. Serum PIVKA-II were quantified by an automated chemiluminescence assay. Multivariable Cox proportional hazards regression models were used to identify predictors for HCC and death. Serial on-treatment PIVKA-II levels after VR were investigated. RESULTS: Overall, 293 CHB-related cirrhosis patients were included. At VR, the mean age was 55, and the mean PIVKA-II level was 35 mAU/mL. After a mean follow-up of 78 months, 76 patients developed HCC and 19 died. After adjustment for confounding factors, alpha-fetoprotein >7 ng/mL (hazard ratio [HR]: 2.84, 95% confidence interval [CI]: 1.73-4.67) and PIVKA-II >50 mAU/mL (HR: 2.46, 95%CI: 1.35-4.49) at VR significantly predicted HCC development. In patients with alpha-fetoprotein ≤10 ng/mL or ≤20 ng/mL at VR, PIVKA-II >50 mAU/mL increased 2.45 or 3.16-fold risk of HCC, respectively. PIVKA-II levels after VR increased serially in patients who developed HCC afterwards. CONCLUSION: In patients with CHB-related cirrhosis, serum alpha-fetoprotein >7 ng/mL and PIVKA-II >50 mAU/mL at the time of antiviral therapy-induced VR is associated with a greater risk of HCC. PIVKA-II is a predictive marker for HCC in patients with low normal alpha-fetoprotein level.

Gray matter reduction related to decreased serum creatinine and increased triglyceride, Hemoglobin A1C, and low-density lipoprotein in subjects with obesity.

PURPOSE: Altered brain volume and metabolic variables have been found in subjects with obesity. However, the role of metabolic parameters in gray matter volume (GMV) has been poorly investigated. This study aimed to investigate the relationship between the metabolic parameters and brain volume in subjects with obesity. METHODS: Thirty-seven subjects with obesity and 39 age and sex matched normal-weight controls were included in this study. Eighteen of the 37 participants who underwent sleeve gastrectomy were included in the longitudinal analysis. Blood samples and high-resolution 3T T1-weighted magnetic resonance images were collected. Metabolic parameters in plasma and GMV were measured. RESULTS: Multiple linear regression analysis showed that gray matter reduction in several cognition-related cortices including right angular gyrus, superior occipital cortex, superior parietal cortex, and cerebellum was related to decreased creatinine, as well as increased triglyceride, HbA1c, and low-density lipoprotein in plasma in subjects with obesity. Weight loss after the surgery induced significant recovery of altered metabolic parameters and decreased gray matter volume. Furthermore, changes in the four metabolic parameters before and after the surgery were associated with changes in gray matter volume. CONCLUSION: Our results suggest that the gray matter reduction is related to decreased creatinine as well as increased triglyceride, HbA1c, and low-density lipoprotein in plasma in subjects with obesity.

Nonintubated laryngomicrosurgery with Transnasal Humidified Rapid-Insufflation Ventilatory Exchange: A case series.

BACKGROUND: Nonintubation anaesthesia for laryngomicrosurgery (LMS) provides both excellent visualization of the surgical field and complete examination on vocal cord. However, adequate oxygenation remains challenging during nonintubated LMS. Recently, transnasal humidified rapid-insufflation ventilator exchange (THRIVE) has been reported effectively maintaining apneic oxygenation in patient with difficult airways. The feasibility and safety of nonintubated LMS with THRIVE was evaluated in this case series. METHODS: From September 2016 to February 2017, a total of 23 patients receiving nonintubated LMS were included. Anaesthesia was induced and maintained through target-controlled propofol infusion and muscle relaxation with THRIVE oxygen support. Perioperative data were collected from medical records and analysed. RESULTS: The mean (±SD) duration of the operation was 12.4 (±4.4) min. The mean (±SD) total anaesthesia time (from induction to emergence) was 24.1 (±6.4) min. 22 patients received nonintubated LMS with surgical satisfaction without intraoperative desaturation. One patient who underwent laryngeal tumour biopsy experienced a single episode of desaturation. A 5.5-mm tracheal tube was needed for short-term mechanical ventilation to regain SpO2 to 100%. No significant complication was noted in all patients. All patients discharged as per schedule on the next day after surgery as intubated LMS patients in our hospital. CONCLUSION: Nonintubated LMS with THRIVE is a feasible and safe alternative to intubated LMS with a small size tracheal tube to provide a better surgical field. However, for patients with easy-bleeding tumor, intubated LMS remains suggestive for better airway protection.

Effect of normal aging on the structure of marginal division of neostriatum as measured by MR phase imaging and diffusion tensor imaging.

PURPOSE: To investigate the structural changes of marginal division (MrD) which is the high intensity zone between globus pallidus and putamen on phase image in the human brain. MATERIALS AND METHODS: The structural changes of MrD were investigated based on MR phase imaging and diffusion tensor imaging (DTI) data at 3.0 Tesla (T) MR scanner in 72 volunteers. Phase value, including high iron components (HIC), low iron components (LIC), LIC ratio, and average iron components (AIC), were obtained using histogram analysis about the head of caudate nucleus (CA), globus pallidus (GP), putamen (PU), and MrD. The structural measurement of MrD was applied on corrected phase images (CPIs). Average apparent diffusion coefficient (ADC) values and fractional anisotropy (FA) values were calculated based on DTI data. RESULTS: MrD showed negative correlation for LIC with aging, with the highest HIC (left/right 2149.3 ± 19.6/2155.9 ± 17.9) and LIC (left/right 1996.6 ± 18.2/1999.6 ± 20.7), the lowest LIC ratio (left/right 21.5% ± 7.9%/19.4% ± 8.0%), and the highest AIC (left/right 2116.4 ± 21.4/2124.7 ± 21.0). The width (Head: left/right 2.01 ± 0.41 mm/1.86 ± 0.36 mm; Body: left/right 1.84 ± 0.38 mm/1.49 ± 0.29 mm; Tail: left/right 1.17 ± 0.36 mm/1.05 ± 0.23 mm) and area (left/right 49.44 ± 9.71 mm2 /42.75 ± 8.80 mm2 ) of MrD showed negative correlation with aging, presenting gradually narrower pattern based on CPIs. Average ADC value (left/right 0.69 ± 0.04 10-3 mm2 /s / 0.71 ± 0.03 10-3 mm2 /s) revealed negative correlation, while FA value (left/right 0.19 ± 0.03/0.22 ± 0.03) revealed positive correlation with aging. CONCLUSION: The findings suggested that the structure measurements based on CPIs and DTI could provide a simple and effective tool for the evaluation of MrD in vivo in the human brain and for the assessment of the changes seen with aging. LEVEL OF EVIDENCE: 1 J. MAGN. RESON. IMAGING 2017;45:1343-1351.

Correlations between plasma levels of amino acids and nonmotor symptoms in Parkinson's disease.

Converging evidence suggests that changes in plasma levels of amino acids are involved in Parkinson's disease (PD), but their roles in nonmotor symptoms (NMS) of PD remain unclear. The aim of this study was to evaluate the correlations between plasma amino acids and NMS of PD. Plasma levels of aspartate (Asp), glutamate (Glu), glycine (Gly) and γ-aminobutyric acid (GABA) were measured in 92 PD patients and 60 healthy controls. Four NMS, including depression, pain, sleep disturbances and autonomic dysfunction were assessed in enrolled subjects using the Hamilton Depression Scale, the short form of the McGill Pain Questionnaire, the Pittsburgh Sleep Quality Index and the Scale for Outcomes in Parkinson's disease for Autonomic Symptoms, respectively. Hierarchical multiple regression analysis was used to evaluate the correlations between plasma levels of amino acids and NMS. PD patients exhibited significantly higher scores of NMS scales and lower plasma levels of amino acids compared to healthy controls. Within the PD group, plasma levels of Asp and Glu were negatively associated with the severity of depression and sleep disturbances. Moreover, decreased plasma level of GABA was correlated with more severe symptoms of sleep disturbances. After controlling for gender, disease duration, severity of motor symptoms and anti-parkinsonian medications, Glu but not Asp remained significantly associated with depression, along with Asp, GABA but not Glu remained negatively associated with sleep disturbances. The altered plasma levels of amino acids may be implicated in the pathogenesis of NMS of PD.

Dialysis-functionalized microfluidic platform for in situ formation of purified liposomes.

Continuous-flow microfluidic devices have been extensively used for producing liposomes due to their high controllability and efficient synthesis processes. However, traditional methods for liposome purification, such as dialysis, gel chromatography, and ultrafiltration, are incompatible with microfluidic devices, which would dramatically restrict the efficiency of liposome synthesis. In this study, we developed a dialysis-functionalized microfluidic platform (DFMP) for in situ formation of purified drug-loaded liposomes. The device was successfully fabricated by using a high-resolution projection micro stereolithography (PµSL) 3D printer. The integrated DFMP consists of a microfluidic mixing unit, a microfluidic dialysis unit, and a dialysis membrane, enabling the liposome preparation and purification in one device. The purified ICG-loaded liposomes prepared by DFMP had a smaller size (264.01±5.34 nm to 173.93±10.71 nm) and a higher encapsulation efficiency (EE) (43.53±0.07% to 46.07±0.67%). In vivo photoacoustic (PA) imaging experiment demonstrated that ICG-loaded liposomes purified with microfluidic dialysis exhibited a stronger penetration and accumulation (2-3 folds) in tumor sites. This work provides a new strategy for one-step production of purified drug-loaded liposomes.

Liposomes Loaded with 5-Fluorouracil Can Improve the Efficacy in Pathological Scars.

Introduction: Pathological scars, such as hypertrophic scars and keloids, are characterized by the proliferation of fibroblasts and the deposition of collagen that often cause pruritus, pain, and disfigurement. Due to their high incidence and deformity, pathological scars have resulted in severe physical and psychological trauma for patients. Intralesional injection of 5-fluorouracil (5-Fu) is a recommended option for treating pathological scars. However, the efficacy of 5-Fu injection was limited and unstable due to limited drug penetration and short retention time. Methods: Liposomes are promising carriers that have advantages, such as high biocompatibility, controlled release property, and enhanced clinical efficacy. Here, we constructed a transdermal 5-Fu-loaded liposome (5-Fu-Lip) to provide a more effective and safer modality to scar treatment. Results: Compared to 5-Fu, 5-Fu-Lip showed superior ability in inhibiting primary keloid fibroblasts proliferation, migration, and collagen deposition, and also significantly inhibited human umbilical vein endothelial cells (HUVECs) proliferation and microvessel construction. In vivo experiments demonstrated that 5-Fu-Lip can significantly reduce the severity of hypertrophic scars in a rabbit ear wounding model. Discussion: 5-Fu-Lip provides a promising strategy to improve drug efficacy, which has great potential in the treatment of pathological scars.

Low-Frequency Ultrasound Sensitive Piezo1 Channels Regulate Keloid-Related Characteristics of Fibroblasts.

Keloids are benign fibroproliferative tumors that severely diminish the quality of life due to discomfort, dysfunction, and disfigurement. Recently, ultrasound technology as a noninvasive adjuvant therapy is developed to optimize treatment protocols. However, the biophysical mechanisms have not yet been fully elucidated. Here, it is proposed that piezo-type mechanosensitive ion channel component 1 (Piezo1) plays an important role in low-frequency sonophoresis (LFS) induced mechanical transduction pathways that trigger downstream cellular signaling processes. It is demonstrated that patient-derived primary keloid fibroblasts (PKF), NIH 3T3, and HFF-1 cell migration are inhibited, and PKF apoptosis is significantly increased by LFS stimulation. And the effects of LFS is diminished by the application of GsMTx-4, the selective inhibitor of Piezo1, and the knockdown of Piezo1. More importantly, the effects of LFS can be imitated by Yoda1, an agonist of Piezo1 channels. Establishing a patient-derived xenograft keloid implantation mouse model further verified these results, as LFS significantly decreased the volume and weight of the keloids. Moreover, blocking the Piezo1 channel impaired the effectiveness of LFS treatment. These results suggest that LFS inhibits the malignant characteristics of keloids by activating the Piezo1 channel, thus providing a theoretical basis for improving the clinical treatment of keloids.

Acoustic hologram-induced virtual in vivo enhanced waveguide (AH-VIEW).

Optical imaging and phototherapy in deep tissues face notable challenges due to light scattering. We use encoded acoustic holograms to generate three-dimensional acoustic fields within the target medium, enabling instantaneous and robust modulation of the volumetric refractive index, thereby noninvasively controlling the trajectory of light. Through this approach, we achieved a remarkable 24.3% increase in tissue heating rate in vitro photothermal effect tests on porcine skin. In vivo photoacoustic imaging of mouse brain vasculature exhibits an improved signal-to-noise ratio through the intact scalp and skull. These findings demonstrate that our strategy can effectively suppress light scattering in complex biological tissues by inducing low-angle scattering, achieving an effective depth reaching the millimeter scale. The versatility of this strategy extends its potential applications to neuroscience, lithography, and additive manufacturing.

A piezoelectric-driven microneedle platform for skin disease therapy.

With over a million cases detected each year, skin disease is a global public health problem that diminishes the quality of life due to its difficulty to eradicate, propensity for recurrence, and potential for post-treatment scarring. Photodynamic therapy (PDT) is a treatment with minimal invasiveness or scarring and few side effects, making it well tolerated by patients. However, this treatment requires further research and development to improve its effective clinical use. Here, a piezoelectric-driven microneedle (PDMN) platform that achieves high efficiency, safety, and non-invasiveness for enhanced PDT is proposed. This platform induces deep tissue cavitation, increasing the level of protoporphyrin IX and significantly enhancing drug penetration. A clinical trial involving 25 patients with skin disease was conducted to investigate the timeliness and efficacy of PDMN-assisted PDT (PDMN-PDT). Our findings suggested that PDMN-PDT boosted treatment effectiveness and reduced the required incubation time and drug concentration by 25% and 50%, respectively, without any anesthesia compared to traditional PDT. These findings suggest that PDMN-PDT is a safe and minimally invasive approach for skin disease treatment, which may improve the therapeutic efficacy of topical medications and enable translation for future clinical applications.

Indocyanine Green-Loaded Liposomes-Assisted Photoacoustic Computed Tomography for Evaluating In Vivo Tumor Penetration of Liposomal Nanocarriers.

Liposomes possess the potential to enhance drug solubility, prolong the duration of circulation, and augment drug accumulation at the tumor site through passive and active targeting strategies. However, there is a lack of studies examining the in vivo tumor penetration capabilities of liposomes of varying sizes, which hampers the development of drug delivery systems utilizing liposomal nanocarriers. Here, we present an indocyanine green (ICG)-loaded liposomes-assisted photoacoustic computed tomography (PACT) for directly evaluating the tumor penetration ability of liposomal nanocarriers in vivo. Through the utilization of microfluidic mixing combined with extrusion techniques, we successfully prepare liposomes encapsulating ICG in both large (192.6 ± 8.0 nm) and small (61.9 ± 0.6 nm) sizes. Subsequently, we designed a dual-wavelength PACT system to directly monitor the in vivo tumor penetration of large- and small-size ICG-encapsulated liposomes. In vivo PACT experiments indicate that ICG-loaded liposomes of smaller size exhibit enhanced penetration capability within tumor tissues. Our work presents a valuable approach to directly assess the penetration ability of liposomal nanocarriers in vivo, thereby facilitating the advancement of drug delivery systems with enhanced tumor penetration and therapeutic efficacy.

Dual-Wavelength Photoacoustic Computed Tomography with Piezoelectric Ring-Array Transducer for Imaging of Indocyanine Green Liposomes Aggregation in Tumors.

Recently, indocyanine green (ICG), as an FDA-approved dye, has been widely used for phototherapy. It is essential to obtain information on the migration and aggregation of ICG in deep tissues. However, existing fluorescence imaging platforms are not able to obtain the structural information of the tissues. Here, we prepared ICG liposomes (ICG-Lips) and built a dual-wavelength photoacoustic computed tomography (PACT) system with piezoelectric ring-array transducer to image the aggregation of ICG-Lips in tumors to guide phototherapy. Visible 780 nm light excited the photoacoustic (PA) effects of the ICG-Lips and near-infrared 1064 nm light provided the imaging of the surrounding tissues. The aggregation of ICG-Lips within the tumor and the surrounding tissues was visualized by PACT in real time. This work indicates that PACT with piezoelectric ring-array transducer has great potential in the real-time monitoring of in vivo drug distribution.

Pharmacoeconomic evaluations of CDK4/6 inhibitors plus endocrine therapy for advanced hormone receptor-positive (HR+) and human epidermal growth factor receptor-2 negative (HER2-) breast cancer: a systematic review.

Background: Hormone receptor-positive (HR+) and human epidermal growth factor receptor-2 negative (HER2-) breast cancer is the most common molecular subtype of breast cancer in many countries, and endocrine therapy remains a mainstay in its treatment. Cyclin-dependent kinase (CDK) 4/6 inhibitors are a new class of targeted agents administered orally that are recommended being used in combination with endocrine therapy as first and second line treatments for advanced HR+/HER2- breast cancer. However, their high prices largely hinder using these drugs in real world settings. To offer a new basis for future research, we investigated the cost-effectiveness of combinations of CDK4/6 inhibitors with endocrine therapy in the treatment of advanced HR+/HER2- breast cancer. Methods: We systematically searched several frequently used databases and identified economic evaluations published from February 2015 to April 2021. The systematic review was performed after retrieving the literatures and extracting data based on inclusion and exclusion criteria. The quality of each selected economic evaluation was assessed by the Consolidated Health Economic Evaluation Reporting Standards (CHEERS). Results: The literature search yielded 161 articles, among which fourteen studies (15 articles) with CHEER scores ranging from 58.33% to 87.50% entered the final analysis. Markov models were used in most studies. Based on the currently available data, CDK4/6 inhibitors plus endocrine therapy were less cost-effective in first- or second-line treatment of patients with HR+/HER2- advanced breast cancer. However, ribociclib plus letrozole was more cost-effective than palbociclib plus letrozole in the first-line treatment of postmenopausal women. The economic impacts of CDK4/6 inhibitors plus endocrine therapy in non-postmenopausal patients or second-line therapy cannot be fully evaluated due to the limited number of studies. The three most common factors affecting economic outcomes were the prices of CDK4/6 inhibitors, hazard ratios for progression-free survival and overall survival, and health status utility values. Discussion: CDK4/6 inhibitors plus endocrine therapy have shown significantly improved efficacy outcomes in HR+/HER2- metastatic breast cancer (mBC)/advancer breast cancer (ABC) first-line and second-line treatment for endocrine-sensitive and endocrine-resistant populations, while more potential fields including neoadjuvant and adjuvant settings are being identified to benefit a wider range of breast cancer patients. Meanwhile, risk of severe adverse events that more likely to happen in patients treated with CDK4/6 inhibitors can lead to reduced life quality and higher medical costs patients need to afford. The adverse drug reaction related cost in several economic burden studies were explored to be primarily driven by hospitalizations and outpatient, and assessment of cost associated with CDK4/6 inhibitors adverse events is worth further developing. Drug wastage costs were found higher in palbociclib regimen than ribociclib regimen due to different dosing patterns. Moreover, current economic evaluations showed that ribociclib plus letrozole had better economic benefits than palbociclib plus letrozole for first-line treatment of postmenopausal women with HR+/HER2- ABC.