Clinical benefit and safety profile of cross-line therapy with CDK4/6 inhibitors:a retrospective study of HR+/HER2–advanced breast cancer

Objective:CDK4/6 inhibitors(CDK4/6is)in combination with endocrine therapy have secured a central role in the treatment of hormone receptor(HR)-positive advanced breast cancer(ABC)and have transformed the therapeutic landscape.Cross-line CDK4/6i therapy in which another CDK4/6i is continued after progression on a prior CDK4/6i may still offer advantageous therapeutic effects.Cross-line CDK4/6i therapy is an area of active investigation in the ongoing pursuit to improve outcomes for patients with HR+/human epidermal growth factor receptor 2(HER2)–ABC.Methods:This retrospective study enrolled 82 patients with HR+/HER2–ABC who were treated with cross-line CDK4/6is(abemaciclib,palbociclib,ribociclib,and dalpiciclib)after progression with another CDK4/6i.The primary endpoint was progression-free survival(PFS)according to version 1.1 of the Response Evaluation Criteria in Solid Tumors.Secondary endpoints included toxicity,objective response rate,disease control rate,and overall survival.Adverse events(AEs)were graded according to version 5.0 of the Common Terminology Criteria for Adverse Events,as promulgated by the U.S.Department of Health and Human Services.Results:Eighty-two HR+/HER2–ABC patients who received cross-line CDK4/6i therapy from January 2022 to February 2024 were enrolled.The median age of the patients was 60 years.The median PFS of all patients was 7.6 months(95%CI,5.9-9.2).Cox regression analysis identified lung metastasis and a switch to endocrine therapy following prior CDK4/6i therapy as independent predictive factors for PFS.Notably,patients who previously received abemaciclib and switched to palbociclib upon disease progression had a median PFS of 10.7 months.The strategy of transitioning to chemotherapy after progression on a prior CDK4/6i,then to a subsequent CDK4/6i merits further investigation.Hematologic toxicity was the most common grade≥3 AEs.No instances of fatal safety events were observed.Conclusions:Cross-line CDK4/6i therapy is associated with significant clinical benefits and manageable safety profiles in patients with HR+/HER2–ABC,which underscores cross-line CDK4/6i therapy potential as an effective treatment strategy.

LA-D-B1,a novel Abemaciclib derivative,exerts anti-breast cancer effects through CDK4/6

Background:Regulatory proteins involved in human cellular division and proliferation,cyclin-dependent kinases 4 and 6(CDK4/6)are overexpressed in numerous cancers,including triple-negative breast cancer(TNBC).TNBC is a common pathological subtype of breast cancer that is prone to recurrence and metastasis,and has a single treatment method.As one of the CDK4/6 inhibitors,abemaciclib can effectively inhibit the growth of breast tumors.In this study,we synthesized LA-D-B1,a derivative of Abemaciclib,and investigated its anti-tumor effects in breast cancer.Methods:Cellular viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Cell cloning and migration abilities were determined by colony formation assay and wound healing assay.Cell invasion abilities and adhesion were determined by cell invasion assay and cell adhesion assay.The impact of compound LA-D-B1 on cell proliferation and the cell cycle was analyzed through Western blotting,which quantified the levels of proteins associated with the cyclin-dependent kinase(CDK)4/6-cyclin D-Rb-E2F pathway.The in vivo anti-tumor activity of compound LA-D-B1 was investigated using a chick chorioallantoic membrane(CAM)model.Results:The study demonstrated that LA-D-B1 effectively suppressed breast cancer cell proliferation,induced apoptosis,and caused cell cycle arrest.Furthermore,LA-D-B1 reduced the expression of key proteins in the CDK4/6-cyclin D-Rb-E2F pathway,including CDK4,CDK6 and E2F1.The results also indicated significant antitumor activity of LA-D-B1 in a transplanted tumor model.Conclusion:In this study,LA-D-B1 demonstrated a potent anti-tumor effect by effectively suppressing cell proliferation and inhibiting cell cycle progression in breast cancer.These findings highlight the potential of LA-D-B1 as a valuable compound for enhancing therapeutic outcomes and controlling the progression of breast cancer.

DDHD2 is involved in the malignant progression of early luminal A breast cancer by changing cell membrane proteins and immune responses functionality

Background:Luminal A breast cancer has the best prognosis of all malignant breast cancer types.In clinical practice,some patients with luminal A breast cancer present with small tumors(usually<20 mm)but with lymph node metastases or even distant organ metastasis.Owing to their insensitivity to chemotherapy and the lack of conclusive clinical evidence,there is a significant gap in research on luminal A breast cancer with high invasiveness.This study aimed to identify genes that drive the invasiveness of luminal A breast cancer and explore the underlying mechanisms.Methods:In this study,we first utilized bioinformatics techniques to analyze differentially expressed mRNAs and enrich common functional pathways to identify the target gene DDHD domain containing 2(DDHD2).We then evaluated the association between DDHD2 expression and patient prognosis,genetic material changes,and transcriptional,translational,and immune responses in luminal A breast cancer.We also conducted experiments at the molecular and cellular levels to validate these biochemical mechanisms.Results:The expression of DDHD2 varied between patients with low-grade luminal A breast cancer with and without lymph node metastases.Our findings demonstrated that DDHD2 exerted carcinogenic effects through various pathways by altering cell adhesion and migration,regulating cell proliferation and apoptosis cycles,and suppressing immune responses.Moreover,a pathway through which DDHD2 inhibited immunity was preliminarily verified.Conclusions:The results revealed a novel role for DDHD2 in promoting the malignant transformation and invasiveness of luminal A breast cancer.Considering its effects on the tumor microenvironment and tumor-infiltrating immune cells in the epithelial-mesenchymal transition,DDHD2 is proposed as a reliable direction for future immunotherapy and a potential target in luminal A breast cancer immune resistance.

MiR-450b-5p enhances the radiosensitivity of HR^(+) and HER2^(−) breast cancer by targeting CDK6

Background:The sensitivity of breast cancer cells to radiation is a key cause of locoregional recurrence after postoperative radiotherapy.Several studies have reported that microRNAs(miRNAs)are involved in the radiosensitivity of human breast cancer cells.One miRNA microarray study showed that miR-450b-5p was overexpressed 13.3-fold in patients with estrogen receptor–positive(ER^(+))and human epidermal growth factor receptor 2–negative(HER2−)breast cancer and no local relapse compared with local relapse patients.However,its underlying mechanism of action remains unknown.Methods:The predicted target mRNAs of miR-450b-5p were screened using the TargetScan,miRDB,and miRWalk databases.Western blotting,quantitative polymerase chain reaction,and dual-luciferase reporter assays explored the association between cyclindependent kinase 6(CDK6)and miR-450b-5p.The cell counting kit-8 assay and flow cytometry detected the proliferation of transfected MCF7 cells.Colony formation and xenograft tumors detected the radiosensitivity of the transfected MCF7 cells.Results:Bioinformatics analysis,Western blotting,quantitative polymerase chain reaction,and dual-luciferase reporter assays demonstrated that CDK6 was the target gene of miR-450b-5p.Furthermore,in vitro and in vivo experiments showed that miR-450b-5p inhibited MCF7 cell proliferation and cell cycle progression,increased the sensitizer enhancement ratio,and decreased the volume of xenograft tumors after irradiation by regulating CDK6.Conclusions:This study demonstrates that miR-450b-5p enhances the radiosensitivity of hormone receptor–positive(HR^(+))and HER2−breast cancer cells and elucidates its mechanism.miR-450b-5p may be considered a therapeutic target in HR^(+)and HER2−breast cancer treated with radiotherapy.

Unveiling the therapeutic potential:KBU2046 halts triple-negative breast cancer cell migration by constricting TGF-β1 activation in vitro

Background:Triple-negative breast cancer(TNBC)is a heterogeneous,recurring cancer characterized by a high rate of metastasis,poor prognosis,and lack of efficient therapies.KBU2046,a small molecule inhibitor,can inhibit cell motility in malignant tumors,including breast cancer.However,the specific targets and the corresponding mechanism of its function remain unclear.Methods:In this study,we employed(3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium)(MTS)assay and transwell assay to investigate the impact of KBU2046 on the proliferation and migration of TNBC cells in vitro.RNA-Seq was used to explore the targets of KBU2046 that inhibit the motility of TNBC.Finally,confirmed the predicted important signaling pathways through RT-qPCR and western blotting.Results:In this study,we found that KBU2046 functioned as a novel transforming growth factor-β(TGF-β1)inhibitor,effectively suppressing tumor cell motility in vitro.Mechanistically,it directly down-regulated leucine-rich repeat-containing 8 family,member E(LRRC8E),latent TGFβ-binding protein 3(LTBP3),dynein light chain 1(DNAL1),and MAF family of bZIP transcription factors(MAFF)genes,along with reduced protein expression of the integrin family.Additionally,KBU2046 decreased phosphorylation levels of Raf and ERK.This deactivation of the ERK signaling pathway impeded cancer invasion and metastasis.Conclusions:In summary,these findings advocate for the utilization of TGF-β1 as a diagnostic and prognostic biomarker and as a therapeutic target in TNBC.Furthermore,our data underscore the potential of KBU2046 as a novel therapeutic strategy for combating cancer metastasis.

BMP-6 inhibits microRNA-21 expression in breast cancer through repressing 6EF1 and AP-1

MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various solid tumors, including breast cancer. Bone morphogenetic protein-6 （BMP-6） has been identified as an inhibitor of breast cancer epithelial-mesenchymal transition （EMT） through rescuing E-cadherin expression. We initiated experi- ments to identify the relationships between miR-21 and BMP-6 in breast cancer progression. Real-time PCR analysis showed that miR-21 expression was very high in MDA-MB-231 cells that expressed little BMP-6. A reverse correla- tion between BMP-6 and miR-21 was also determined in breast cancer tissue samples. Moreover, BMP-6 inhibited miR-21 transcription in MDA-MB-231 cells. In order to investigate how BMP-6 inhibited the miR-21 promoter （miPPR-21）, we constructed a series of miPPR-21 reporters. Luciferase assay results indicated that BMP-6 inhibited miPPR-21 activity through the E2-box and AP-l-binding sites. We also demonstrated that both δEF1 and TPA in- duced miR-21 expression. Using site-directed mutation and CHIP assay, we found that δEF1 induced miPPR-21 ac- tivity by binding to the E2-box on miPPR-21. Moreover, TPA triggered miPPR-21 activity through the AP-I binding sites. BMP-6 treatment significantly reduced the binding of these factors to miPPR-21 by decreasing the expression of δEF1 and c-Fos/c-Jun. We also demonstrated that BMP-6-induced downregulation of miR-21 modified the activ- ity of PDCD4 3＇UTR and inhibited MDA-MB-231 cell invasion. δEF1 overexpression and TPA induction blocked this inhibitory effect of BMP-6. In conclusion, BMP-6-induced inhibition of miR-21 suggests that BMP-6 may function as an anti-metastasis factor by a mechanism involving transcriptional repression of miR-21 in breast cancer.

Circulating tumor cells(CTCs)in breast cancer:a diagnostic tool for prognosis and molecular analysis

Metastatic breast cancer （MBC） is characterized by a combination of tumor growth, proliferation and metastatic progression and is typically managed with palliative intent. The benefit of standard systemic therapies is relatively limited and the disease is considered incurable suggesting the need to investigate the biological drivers of the various phases of the metastatic process in order to improve the selection of molecularly driven therapies. The detection, enumeration and molecular analysis of circulating tumor cells （CTCs） provide an intriguing opportunity to advance this knowledge. CTCs enumerated by the Food and Drugs Administration-cleared CellSearchTM system are an independent prognostic factor of progression- free survival （PFS） and overall survival （OS） in MBC patients. Several published papers demonstrated the poor prognosis for MBC patients that presented basal CTC count _〉5 in 7.5 mL of blood. Therefore, the enumeration of CTCs during treatment for MBC provides a tool with the ability to predict progression of disease earlier than standard timing of anatomical assessment using conventional radiological tests. During the metastatic process cancer cells exhibit morphological and phenotypic plasticity undergoing epithelial- mesenchymal transition （EMT）. This important phenomenon is associated with down regulation of epithelial marker （e.g., EpCAM） with potential limitations in the applicability of current CTCs enrichment methods. Such observations translated in a number of investigations aimed at improving our capabilities to enumerate and perform molecular characterization of CTCs. Theoretically, the phenotypic analysis of CTCs can represent a ＂liquid＂ biopsy of breast tumor that is able to identify a new potential target against the metastatic disease and advance the development and monitoring of personalized therapies.

Enterolactone modulates the ERK/NF-κB/Snail signaling pathway in triple-negative breast cancer cell line MDA-MB-231 to revert the TGF-β-induced epithelial–mesenchymal transition

Objective:Triple-negative breast cancer(TNBC)is highly metastatic,and there is an urgent unmet need to develop novel therapeutic strategies leading to the new drug discoveries against metastasis.The transforming growth factor-β(TGF-β)is known to promote the invasive and migratory potential of breast cancer cells through induction of epithelial–mesenchymal transition(EMT)via the ERK/NF-κB/Snail signaling pathway,leading to breast cancer metastasis.Targeting this pathway to revert the EMT would be an attractive,novel therapeutic strategy to halt breast cancer metastasis.Methods:Effects of enterolactone(EL)on the cell cycle and apoptosis were investigated using flow cytometry and a cleaved caspase-3 enzyme-linked immunosorbent assay(ELISA),respectively.Effects of TGF-βinduction and EL treatment on the functional malignancy of MDA-MB-231 breast cancer cells were investigated using migration and chemo-invasion assays.The effects of EL on EMT markers and the ERK/NF-κB/Snail signaling pathway after TGF-βinduction were studied using confocal microscopy,quantitative reverse transcription polymerase chain reaction(q RT-PCR),Western blot,and flow cytometry.Results:Herein,we report that EL exhibits a significant antimetastatic effect on MDA-MB-231 cells by almost reverting the TGF-β-induced EMT in vitro.EL downregulates the mesenchymal markers N-cadherin and vimentin,and upregulates the epithelial markers E-cadherin and occludin.It represses actin stress fiber formation via inhibition of mitogen-activated protein kinase p-38(MAPK-p38)and cluster of differentiation 44(CD44).EL also suppresses ERK-1/2,NF-κB,and Snail at the m RNA and protein levels.Conclusions:Briefly,EL was found to inhibit TGF-β-induced EMT by blocking the ERK/NF-κB/Snail signaling pathway,which is a promising target for breast cancer metastasis therapy.

Adipocyte-derived SFRP5 inhibits breast cancer cells migration and invasion through Wnt and epithelial-mesenchymal transition signaling pathways

Objective:Obesity is closely associated with metastasis in breast cancer patients.Secreted frizzled-related protein 5(SFRP5),one of the novel adipokines with anti-inflammatory properties,is associated with obesity.This study aims to study the role of SFRP5 in the crosstalk between obesity and breast cancer metastasis and identify the underlying mechanism.Methods:3T3-L1 pre-adipocytes were differentiated to mature adipocytes and a hypertrophic adipocyte model was induced with palmitic acid(PA).Cell motility was measured in MDA-MB-231 and MCF-7 breast cancer cells co-cultured with adipocytes conditioned medium(CM)with or without SFRP5 protein.Wnt and epithelialmesenchymal transition(EMT)signal pathways were investigated by western blot.Circulating SFRP5 level in 218 breast cancer patients and the association with clinicopathologic characteristics of breast cancer were further determined.Online databases ENCORI and PREDICT Plus were used to exam the link between SFRP5 and prognosis.Results:Reduced SFRP5 level was detected in the hypertrophic adipocyte model.Recombinant SFRP5 protein inhibited MDA-MB-231 and MCF-7 cells invasion and migration induced by PA-treated adipocyte CM,and SFRP5 inhibition by specific antibody reversed the effect of SFRP5.Furthermore,SFRP5 significantly inhibited Wnt and downstream EMT in breast cancer cells.Low circulating SFRP5 level correlated with body mass index(BMI),lymph node(LN)metastasis,TNM stage and high Ki67 expression in breast cancer patients.Increased SFRP5 level was associated with favorable predicted survival.Kaplan-Meier curves showed high SFRP5 level in tumor tissue was associated with better outcome of breast cancer patients.Conclusions:Our findings demonstrated SFRP5 is a vital adipokine that mediates the crosslink between obesity and the metastatic potential of breast cancer.Promotion of SFRP5 expression in the adipose microenvironment may represent a novel approach for preventing breast cancer metastasis.

Tea polyphenols inhibit the growth and angiogenesis of breast cancer xenografts in a mouse model

Objective:To investigate the anti-angiogenic effect of tea polyphenols(TPS)on breast cancer and normal tissues in a mouse model.Methods:Breast cancer was successfully implanted into 48 BALB/c mice,which were then randomly divided into a TP oral gavage group,a TP local injection group,a ginsenoside Rg3 group,and a model control group according to a random number table.The tumor inhibitory rates of each group were calculated,while microvessel density(MVD)and the expression of vascular endothelial growth factor(VEGF),basic fibroblast growth factor(bFGF),and tissue inhibitor of metalloproteinase(TIMP-2)were detected by immunohistochemistry.Results:TPs could inhibit the growth of breast cancer xenografts in the mouse model.The tumor inhibition rates of the TP oral gavage and TP local injection groups were 37.43%and 40.94%,respectively.Compared with the model control group,MVD and VEGF and bFGF expression was downregulated(all P<.05),whereas TIMP-2 expression was elevated in the TP oral gavage and TP local injection groups(P=.015 and P=.032).TPs showed no significant effect on MVD and VEGF and TIMP-2 expression in the heart,brain,and kidney of the mouse model.Conclusion:TPs can restrict the growth of breast cancer by specifically inhibiting the angiogenesis of breast tumor tissue while having little effect on the normal tissue of important organs including the heart,brain,and kidney.

Epithelial-Mesenchymal Transitions and the Expression of Twist in MCF-7/ADR, Human Multidrug-Resistant Breast Cancer Cells

OBJECTIVE To study the expression levels of Twist and epithelialmesenchymal transitions in multidrug-resistant MCF-7/ADR breast cancer cells, and to study the relationship between multidrug resistance （MDR） and metastatic potential of the cells. METHODS RT-PCR, immunohistochemical and Western blotting methods were used to examine the changes of expression levels of the transcription factor Twist, E-cadherin and N-cadherin in the MCF-7 breast cancer cell line and its multidrug-resistant variant, MCF-7/ADR. RESULTS In MCF-7 cells, the expression of E-cadherin can be detected, but there is no expression of Twist or N-cadherin. In MCF-7/ADR cells, E-cadherin expression is lost, but the expression of two other genes was significantly positive. CONCLUSION Epithelial-mesenchymal transitions induced by Twist, may have a relationship with enhanced invasion and metastatic potential during the development of multidrug-resistant MCF-7/ADR breast cancer cells.

The detection of micrometastases in the peripheral blood of patients with breast cancer for hSBEM mRNA and CD44V6 mRNA

Objective： Successful treatment of breast cancer greatly depends on the early detection of its metastasis, therefore a sensitive and specific biomarker for detecting dissemination of the cancer cells will help to achieve this goal. This study was to evaluate the prognostic significance of human small breast epithelial mucin （hSBEM） and CD44V6 in breast cancer. Methods： The expressions of hSBEM mRNA and CD44V6 mRNA were detected with nested reverse transcription polymerase chain reaction （nested RT-PCR） in 67 samples of breast cancer and adjacent normal breast tissue, 16 samples of breast benign lesions tissue, and 67 specimens of peripheral blood from patients with breast cancer, 16 specimens of benign breast lesions, 20 specimens of healthy volunteers, and 25 （each five cases） other carcinomas tissue samples, including those of gastric carcinoma, colorectal carcinoma, esophageal carcinoma, lung carcinoma, and ovary carcinoma, were analyzed for hSBEM mRNA expression by nested RT-PCR. Results： hSBEM mRNA expression was observed in 62/67 （92.54%） of breast cancer, 14/16 （87.50%） of breast benign lesions and 59/67 （88.05%） of normal breast tissue, with no significant differences between them （P 〉 0.05）. None of the samples from other cancer tissues were positive. In peripheral blood the expression of hSBEM mRNA was detected in 34/67 （50.75%） from patients with breast cancer, with significant increasing （P 〈 0.05） in the cases of metastatic disease （stage Ⅳ） and those with lymph node metastasis compared with localized disease （stage Ⅰ, Ⅱ and Ⅲ） and without lymph node metastasis, but its expression was not found in peripheral blood of patients with benign breast lesions or healthy volunteers. Although CD44V6 mRNA was significantly higher in breast cancer than in benign breast lesions tissue and normal breast tissue, its expression in peripheral blood show no significant difference （P 〉 0.05） in the patients with breast cancer （82.09%）, benign breast lesion （75.00%）, or healthy volunteers （70.00%）. The expressions of hSBEM mRNA and CD44V6 mRNA had no correlation with the age of the patients, size of primary tumor, histological type and estrogen or progestin receptor status （P 〉 0.05）. Conclusion： hSBEM mRNA, as assessed by nested RT-PCR, shows a mammary-specific and mammary-sensitive expression, and is a sensitive indicator of hematogeneous spread of breast cancer cell, while CD44V6 shows low sensitivity and specificity in detecting dissemination of breast cancer cell in peripheral blood, hSBEM mRNA is a promising molecular biomarker for detecting breast cancer micrometastases.

Downregulation of MTDH using short hairpin RNA inhibited EMT in breast cancer cells

Objective： Metadherin （MTDH） could regulate epithelial-mesenchymal transition （EMT）, and is involved in tumor metastasis.This study was designed to observe the effect of MTDH-short hairpin RNA （shRNA） on EMT, and the role of MTDH in breast tumor metastasis. Methods： RNA interference plasmid that can express shRNA targeting MTDH or shRNA-nega- tive plasmid that does not match any known human coding mRNA was designed, constructed and named MTDH-shRNA and MTDH-shRNA-neg, which were transiently transfected into MDA-MB-231 cells using LipofectamineTM2000. After 48 h, the levels of MTDH, E-cadherin and a-SMA expression were determined by reverse transcription-polymerase chain reactin （RT- PCR）, Western blot. The invasion and immigration potential was examined by Transwell chamber invasion or migration assay. Results： Compared with MDA-MB-231, the MTDH mRNA level was down-regulated by 41.2%, the MTDH protein level was down-regulated by 40.3%. The invasion and immigration potential of MDA-MB-231 cells was decreased after transfection of MTDH-shRNA. Compared with MDA-MB-231 or MTDH-shRNA-neg, the mRNA and protein level of a-SMA was reduced and E-candherin were increased in MTDH-shRNA, with statisticat significance. Conclusion： Downregulation of MTDH increase E-candherin expression and reduced a-SMA expression, which inhibit EMT in MDA-MB-231 cells. This knockdown significantly suppresse migration and invasion in MDA-MB-231 cells.

Abemaciclib, a Recent Novel FDA-Approved Small Molecule Inhibiting Cyclin-Dependant Kinase 4/6 for the Treatment of Metastatic Breast Cancer: A Mini-Review

Abemaciclib (Verzerio®) is a cell cycle inhibitor of both CDK4 and CDK6. In 2017, abemaciclib was approved by the Food and Drug Administration (FDA) and, in 2018 by the European Medicines Agency (EMA) for the treatment of postmenopausal women with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2−) advanced breast cancer. In this mini-review, we provide a series of information for respectively their targets and its selectivity, results on preclinical trial, clinical phase I, II and III trials, and some perspectives. We also describe the batch and flow steps used for the synthesis of this cancer drug.

Impact of cytochrome P450 2D6 polymorphisms on decision-making and clinical outcomes in adjuvant hormonal therapy for breast cancer

BACKGROUND There are concerns that tamoxifen is less effective in Asian women because of the high prevalence of impaired function cytochrome P4502D6(CYP2D6)polymorphisms.AIM To evaluate how knowledge of CYP2D6 genotype impacted the choice of hormonal agent and how CYP2D6 genotype and agent were associated with clinical outcomes.METHODS Eighty-two women were recruited.Seventy-eight completed CYP2D6 genotyping and were categorized into poor,intermediate(IM)and extensive or ultra metabolizer phenotypes.Women with poor metabolizer and IM phenotypes were recommended aromatase inhibitors as the preferred agent.RESULTS More than 70%of the women had an IM phenotype,32%an extensive or ultra metabolizer phenotype,and 0%had a poor metabolizer phenotype.Regardless of genotype,more women opted for aromatase inhibitors.Overall,80%of women completed 5 years of hormonal therapy.Five women developed recurrence,3 contralateral breast cancer,5 died,and 1 was diagnosed with a second primary cancer.Five-year recurrence-free and overall survival were slightly better in women with the extensive or ultra metabolizer phenotype compared to those with the IM phenotype,though not statistically significant[P=0.743,hazard ratio(HR):1.441,95%confidence interval(CI):0.191 to 10.17 and P=0.798,HR:1.327,95%CI:0.172 to 9.915,respectively].Women receiving aromatase inhibitors also appeared to have a better,but also nonsignificant,5-year recurrence-free and overall survival(P=0.253,HR:0.368,95%CI:0.031 to 0.258 and P=0.292,HR:0.252,95%CI:0.005 to 4.951,respectively).CONCLUSION The IM phenotype was highly prevalent but was not associated with clinical outcome.

Can cyclin-dependent kinase 4/6 inhibitors convert inoperable breast cancer relapse to operability? A case report

BACKGROUND Pathological complete response(pCR) is rare in hormone receptor-positive(HR+)HER2-negative breast cancer(BC) treated with either endocrine therapy(ET) or chemotherapy. Radical resection of locoregional relapse, although potentially curative in some cases, is challenging when the tumor invades critical structures.The oral cyclin-dependent kinase 4/6 inhibitor palbociclib in combination with ET has obtained a significant increase in objective response rates and progression-free survival in patients with advanced BC and is now being evaluated in the neoadjuvant setting. We present a clinical case of a patient with an inoperable locoregional relapse of HR+ HER2-negative BC who experienced p CR after treatment with palbociclib.CASE SUMMARY We report the clinical case of a 60-year-old patient who presented with an inoperable locoregional relapse of HR+, HER2-negative BC 10 years after the diagnosis of the primary tumor. During a routine follow-up visit, breast magnetic resonance imaging and positron emission tomography/computed tomography revealed a 4-cm lesion in the right subclavicular region, infiltrating the chest wall and extending to the subclavian vessels, but without bone or visceral involvement. Treatment was begun with palbociclib plus letrozole, converting the disease to operability over a period of 6 mo. Surgery was performed and a p CR achieved. Of note, during treatment the patient experienced a very uncommon toxicity characterized by burning tongue and glossodynia associated with dysgeusia, paresthesia, dysesthesia, and xerostomia. A reduction in the dose of palbociclib did not provide relief and treatment with the inhibitor was thus discontinued, resolving the tongue symptoms. Laboratory exams were unremarkable. Given that this was a late relapse, the tumor was classified asendocrine-sensitive, a condition associated with high sensitivity to palbociclib.CONCLUSION This case highlights the potential of the cyclin-dependent kinase 4/6 inhibitor plus ET combination to achieve pCR in locoregional relapse of BC, enabling surgical resection of a lesion initially considered inoperable.

CDK4/6 inhibitors in the treatment of hormone receptor-positive, HER2-negative advanced breast cancer

Endocrine therapy(ET)is the therapy backbone of hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negati ve advanced breast cancer.However,there are about 20%HR positive patients with no response to ET due to primary or acquired ET resistance.In this background,many agents have been studied to overcome ET resistance and of which the important agents are cyclin-dependent kinase 4/6(CDK4/6)inhibitors.The prognosis of advanced breast cancer has been improved by combing ET with CDK4/6 inhibitors.In this review,we mainly focused on the CDK4/6 inhibitors in the treatment of HR-positive,HER2-negative advanced breast cancer and discussed the action mechanisms of CDK4/6 inhibitors alone or combined with ET.We also summarized several molecular features that would predict response or resistance to CDK4/6 inhibitors.In addition,we put forward possible strategies to overcome CDK4/6 inhibitor resistance according to the latest research.

Impact of Drug-Drug Interaction between CDK4/6 Inhibitors and Proton Pump Inhibitors on Survival Outcomes in the Treatment of Metastatic Breast Cancer—Real World Data from a Portuguese Center

Introduction: Proton pump inhibitors (PPi) are widely prescribed, including in patients undergoing treatment for advanced breast cancer (ABC). Due to the pharmacokinetic characteristics of the CDK4/6 inhibitor (Ci) palbociclib a drug interaction with PPi was hypothesized. It was shown in a retrospective study that this association was an independent predictive factor for worse progression-free survival (PFS). Objective: To verify the impact of concomitant administration of PPi with Ci on overall survival (OS) and PFS. Material and Methods: This is a retrospective cohort study of patients treated with Ci for HR+HER2-ABC in the period from Feb/2017 to Aug/2020. SPSS software was used for data processing. Univariate analysis was done by the Kaplan-Meier method and log-rank test, and multivariate analysis by COX regression. P-value < 0.05 was considered significant. Results: 80 patients were included. The median age at diagnosis of ABC was 56 years (25 - 75). Treatment with Ci was 1st line for ABC in 68.8%. Choice of Ci was palbociclib in 73.8% (n = 59) and ribociclib in 26.3% (n = 21). The hormone partner was a nonsteroidal aromatase inhibitor in 45.0%, and fulvestrant in 55.0% of cases. 37.5% of patients were on PPi, and 70.0% of them were during the entire treatment (23.3% omeprazole, 73.4% pantoprazole, 3.3% others). Patients taking concomitant PPi and Ci had lower OS (OS-3 years 42.6% vs. 63.4%, p = 0.254) and PFS (PFS med 15 m. vs. 21 m., p = 0.733), although with no statistically significant difference. Discussion: In the sample, there was a numerical difference, without the statistical significance in the use of PPi in the survival of patients under Ci. This difference could be more evident with a longer follow-up and a larger sample size. This study intends to alert to the growing importance of checking for drug interactions. Polymedication, advanced age and the presence of several comorbidities are real problems in patients with ABC. Conclusion: Real-world data from this center demonstrate a negative, non-statistically significant impact of PPi treatment on survival outcomes, in patients treated with Ci for HR+HER2-ABC.

Mechanism of Ginsenoside Rh1 in Regulating Breast Cancer Cell Extravasation Based on CCL20- CCR6

Objective:To explore the regulatory mechanism of ginsenoside Rh1 on breast cancer cell extravasation based on CCL20-CCR6.Methods:In 2021,a total of 34 patients with breast cancer were treated in Baoding First Central Hospital.During hospitalization,pathological examinations were performed,and all the patients were diagnosed with invasive ductal carcinoma.Out of the 34 cases,16 cases were found to have CCR6 expression in breast cancer tissues,in which they were recorded as the CCR6 expression group,whereas 18 cases did not have CCR6 expression;these cases were recorded as the CCR6 non-expression group.During the same period,21 normal patients were selected as the control group.The peripheral blood CCL20 level and the expression of CCR6 on the surface of CD3+T lymphocytes were analyzed.The extracts of cancer cells were collected,purified,and cultured,and the effect of ginsenoside Rh1 on the invasion and metastasis of breast cancer cells was analyzed.Results:The peripheral blood CCL20 level in the CCR6 expression group was significantly higher than that in the CCR6 non-expression group and the control group,in which p<0.05,indicating that the difference was statistically significant;at 12,24,and 48 hours,the cell survival rate of each dose group was significantly higher than that of the blank control group and the dimethyl sulfoxide(DMSO)group(p<0.05).At 48 hours,comparing the low-dose group with the high-dose group,the cell survival rate significantly decreased(p<0.05).Compared with the blank control group and DMSO group,the invasion ability of breast cancer cells could be reduced in both,high-and medium-dose groups,where p<0.05,indicating that the difference was statistically significant.Conclusion:CCL20 may play a role in the pathogenesis of certain breast cancers,and ginsenoside Rh1 can effectively regulate the invasion and migration of breast cancer cells.

A Systematic Review of Economic Evaluation of CDK4/6 Inhibitors in HR+/HER2-Advanced Breast Cancer

Objective To review the domestic and foreign economic studies on CDK4/6 inhibitors in first-line or second-line treatment of HR+/HER2-advanced breast cancer,and to analyze the main methodologies and research results.Methods Systematic literature review was used to search PubMed,EMBASE,Cochrane Library,CNKI,CBM,and Wanfang database.The incremental cost-effectiveness ratio was taken as the main outcome index,and all pharmacoeconomic evaluations with CDK4/6 inhibitors as intervention measures were included,such as Palbociclib,Ribociclib,and Abemaciclib.According to the Quality of Health Economic Studies Instrument,the quality of the included articles was evaluated,and then the included literature was analyzed.Results and Conclusion A total of 16 pharmacoeconomic evaluation studies were included,mainly from the perspective of national healthcare systems or third-party payers.Only 2 studies focused on second-line treatment,and the remaining treatment levels were first-line treatment.In terms of model structure,7 studies adopted the Markov model,6 studies adopted the PSM model,and 3 studies adopted the DES model.The basic analysis results showed that CDK4/6 inhibitor combined with endocrine regimen was not economical compared with endocrine alone regimen when the threshold was the conventional willingness to pay(WTP)value of each country.The uncertainty analysis included deterministic sensitivity analysis and probability sensitivity analysis.The included studies are all Cost-Utility Analysis with high-quality evaluation,which can provide evidence support for health-related decision-makers in decision-making.It can also provide methodological reference for the economic evaluation of other targeted drugs.