PRaG 3.0 therapy for human epidermal growth factor receptor 2-positive metastatic pancreatic ductal adenocarcinoma:A case report

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly fatal disease with limited effective treatment especially after first-line chemotherapy.The human epidermal growth factor receptor 2(HER-2)immunohistochemistry(IHC)positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC.CASE SUMMARY We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn’t have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment.A novel combination therapy PRaG 3.0 of RC48(HER2-antibody-drug conjugate),radio-therapy,PD-1 inhibitor,granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month.She had not developed any grade 2 or above treatment-related adverse events at any point.Percentage of peripheral CD8^(+) Temra and CD4^(+) Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy.CONCLUSION PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.

Inetetamab combined with S-1 and oxaliplatin as first-line treatment for human epidermal growth factor receptor 2-positive gastric cancer

BACKGROUND Patients with human epidermal growth factor receptor 2(HER2)-positive advanced gastric cancer have poor outcomes.Trastuzumab combined with chemotherapy is the first-line standard treatment for HER2-positive advanced gastric cancer.Inetetamab is a novel anti-HER2 drug,and its efficacy and safety in gastric cancer have not yet been reported.AIM To evaluate the efficacy and safety of the S-1 plus oxaliplatin(SOX)regimen combined with inetetamab as a first-line treatment for HER2-positive advanced gastric cancer.METHODS Thirty-eight patients with HER2-positive advanced gastric cancer or gastroeso-phageal junction adenocarcinoma were randomly divided into two groups:One group received inetetamab combined with the SOX regimen,and the other group received trastuzumab combined with the SOX regimen.After 4-6 cycles,patients with stable disease received maintenance therapy.The primary endpoints were progression-free survival(PFS)and overall survival(OS),and the secondary endpoints were the objective response rate,disease control rate,and adverse events(AEs).RESULTS Thirty-seven patients completed the trial,with 18 patients in the inetetamab group and 19 patients in the trastuzumab group.In the inetetamab group,the median PFS was 8.5 months,whereas it was 7.3 months in the trastuzumab group(P=0.046);this difference was significant.The median OS in the inetetamab group vs the trastuzumab group was 15.4 months vs 14.3 months(P=0.33),and the objective response rate was 50%vs 42%(P=0.63),respectively;these differences were not significant.Common AEs included leukopenia,thrombocytopenia,nausea,and vomiting.The incidence rates of grade≥3 AEs were 56%in the inetetamab group and 47%in the trastuzumab group(P=0.63),with no significant difference.CONCLUSION In the first-line treatment of HER2-positive advanced gastric cancer,inetetamab and trastuzumab showed comparable efficacy.The inetetamab group showed superior PFS,and both groups had good safety.

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance.Human epidermal growth factor receptor 2(HER2)is one of the most important targets in targeted therapy for gastric cancer.Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer.The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified.However,monoclonal antibodies,due to their large molecular weight,inability to penetrate the blood-brain barrier,and drug resistance,lead to decreased therapeutic efficacy,so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer.Small-molecule tyrosine kinase inhibitors,such as lapatinib and pyrrotinib,have the advantages of small molecular weight,penetrating the blood-brain barrier and high oral bioavailability,and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future.Antibo-drug conjugate,such as T-DM1 and T-DXd,can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing,and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab.Therefore,after more detailed stratification of gastric cancer patients,various gastric cancer drugs targeting HER2 are expected to play a more significant role.

Human epidermal growth factor receptor 2 expression level and combined positive score can evaluate efficacy of advanced gastric cancer

BACKGROUND Although treatment options for gastric cancer(GC)continue to advance,the overall prognosis for patients with GC remains poor.At present,the predictors of treatment efficacy remain controversial except for high microsatellite instability.AIM To develop methods to identify groups of patients with GC who would benefit the most from receiving the combination of a programmed cell death protein 1(PD-1)inhibitor and chemotherapy.METHODS We acquired data from 63 patients with human epidermal growth factor receptor 2(HER2)-negative GC with a histological diagnosis of GC at the Cancer Hospital,Chinese Academy of Medical Sciences between November 2020 and October 2022.All of the patients screened received a PD-1 inhibitor combined with chemotherapy as the first-line treatment.RESULTS As of July 1,2023,the objective response rate was 61.9%,and the disease control rate was 96.8%.The median progression-free survival(mPFS)for all patients was 6.3 months.The median overall survival was not achieved.Survival analysis showed that patients with a combined positive score(CPS)≥1 exhibited an extended trend in progression-free survival(PFS)when compared to patients with a CPS of 0 after receiving a PD-1 inhibitor combined with oxaliplatin and tegafur as the first-line treatment.PFS exhibited a trend for prolongation as the expression level of HER2 increased.Based on PFS,we divided patients into two groups:A treatment group with excellent efficacy and a treatment group with poor efficacy.The mPFS of the excellent efficacy group was 8 months,with a mPFS of 9.1 months after excluding a cohort of patients who received interrupted therapy due to surgery.The mPFS was 4.5 months in patients in the group with poor efficacy who did not receive surgery.Using good/poor efficacy as the endpoint of our study,univariate analysis revealed that both CPS score(P=0.004)and HER2 expression level(P=0.015)were both factors that exerted significant influence on the efficacy of treatment the combination of a PD-1 inhibitor and chemotherapy in patients with advanced GC(AGC).Finally,multivariate analysis confirmed that CPS score was a significant influencing factor.CONCLUSION CPS score and HER2 expression both impacted the efficacy of immunotherapy combined with chemotherapy in AGC patients who were non-positive for HER2.

Alterations in the human epidermal growth factor receptor 2-phosphatidylinositol 3-kinase-v-Akt pathway in gastric cancer

AIM:To investigate human epidermal growth factor receptor 2(HER2)-phosphatidylinositol 3-kinase(PI3K)-vAkt murine thymoma viral oncogene homolog signaling pathway.METHODS:We analyzed 231 formalin-fixed,paraffinembedded gastric cancer tissue specimens from Japanese patients who had undergone surgical treatment.The patients' age,sex,tumor location,depth of invasion,pathological type,lymph node metastasis,and pathological stage were determined by a review of the medical records.Expression of HER2 was analyzed by immunohistochemistry(IHC) using the HercepTest TM kit.Standard criteria for HER2 positivity(0,1+,2+,and 3+) were used.Tumors that scored 3+ were considered HER2-positive.Expression of phospho Akt(pAkt) was also analyzed by IHC.Tumors were considered pAkt-positive when the percentage of positive tumor cells was 10% or more.PI3K,catalytic,alpha polypeptide(PIK3CA) mutations in exons 1,9 and 20 were analyzed by pyrosequencing.Epstein-Barr virus(EBV) infection was analyzed by in situ hybridization targeting EBV-encoded small RNA(EBER) with an EBER-RNA probe.Microsatellite instability(MSI) was analyzed by polymerase chain reaction using the mononucleotide markers BAT25 and BAT26.RESULTS:HER2 expression levels of 0,1+,2+ and 3+ were found in 167(72%),32(14%),12(5%) and 20(8.7%) samples,respectively.HER2 overexpression(IHC 3+) significantly correlated with intestinal histological type(15/20 vs 98 /205,P = 0.05).PIK3CA mutations were present in 20 cases(8.7%) and significantly correlated with MSI(10/20 vs 9/211,P < 0.01).The mutation frequency was high(21%) in T4 cancers and very low(6%) in T2 cancers.Mutations in exons 1,9 and 20 were detected in 5(2%),9(4%) and 7(3%) cases,respectively.Two new types of PIK3CA mutation,R88Q and R108H,were found in exon1.All PIK3CA mutations were heterozygous missense singlebase substitutions,the most common being H1047R(6/20,30%) in exon20.Eighteen cancers(8%) were EBV-positive and this positivity significantly correlated with a diffuse histological type(13/18 vs 93/198,P = 0.04).There were 7 cases of lymphoepithelioma-like carcinomas(LELC) and 6 of those cases were EBV-positive(percent/EBV:6/18,33%;percent/all LELC:6/7,86%).pAkt expression was positive in 119(53%) cases but showed no correlation with clinicopathological characteristics.pAkt expression was significantly correlated with HER2 overexpression(16/20 vs 103/211,P < 0.01) but not with PIK3CA mutations(12/20 vs 107/211,P = 0.37) or EBV infection(8/18 vs 103/211,P = 0.69).The frequency of pAkt expression was higher in cancers with exon20 mutations(100%) than in those with exon1(40%) or exon9(56%) mutations.One case showed both HER2 overexpression and EBV infection and 3 cases showed both PIK3CA mutations and EBV infection.However,no cases showed both PIK3CA mutations and HER2 overexpression.One EBVpositive cancer with PIK3CA mutation(H1047R) was MSI-positive.Three of these 4 cases were positive for pAkt expression.In survival analysis,pAkt expression significantly correlated with a poor prognosis(hazard ratio 1.75;95%CI:1.12-2.80,P = 0.02).CONCLUSION:HER2 expression,PIK3CA mutations and EBV infection in gastric cancer were characterized.pAkt expression significantly correlates with HER2 expression and with a poor prognosis.

Role of human epidermal growth factor receptor 2 in gastric cancer:Biological and pharmacological aspects

Amplification of the human epidermal growth factor receptor 2 (HER2) gene and overexpression of the HER2 protein is found in 15%-20% of patients with gastric and gastroesophageal junction cancer. The degree of HER2 overexpression and amplification varies with the location of the carcinoma, with higher expression in the gastroesophageal and proximal parts compared to the distal parts of the stomach. Further, HER2 overexpression and amplification also seems to be related to the Lauren histological classification, with higher levels found in the intestinal phenotype compared to the diffuse and mixed types. The prognostic properties of HER2 overexpression and amplification are still under debate, but a large number of studies seem to indicate that HER2 is a negative prognostic factor. The usefulness of HER2 targeted therapy in gastric cancer was demonstrated in the ToGA trial, where HER2-positive patients with advanced gastric and gastroesophageal junction adenocarcinoma were randomized to receive 5-FU/capecitabine and cisplatin, either alone or in combination with trastuzumab. A statically significant gain in overall survival was seen in patients who received the combined treatment of trastuzumab and chemotherapy. Patients with a strong overexpression of the HER2 protein (IHC3+) specifically benefited from the treatment, with a median overall survival of 17.9 mo. As a consequence of the positive results of the ToGA trial, patients with advanced gastric or gastroesophageal junction adenocarcinoma are now routinely tested for HER2. The ToGA trial must be characterized as a landmark in the treatment of gastric cancer and it has paved the way for a number of new HER2 targeted compounds such as pertuzumab, ado-trastuzumab emtansine, lapatinib, afatinib, and dacomitinib, which are currently undergoing phase II and III clinical testing. Overall, this review will discuss the current status of HER2 in gastric and gastroesophageal junction cancer and the future direction in relation to HER2 target therapy.

Evaluation of human epidermal growth factor receptor 2 status of breast cancer using preoperative multidetector computed tomography with deep learning and handcrafted radiomics features

Objective:To evaluate the human epidermal growth factor receptor 2(HER2)status in patients with breast cancer using multidetector computed tomography(MDCT)-based handcrafted and deep radiomics features.Methods:This retrospective study enrolled 339 female patients(primary cohort,n=177;validation cohort,n=162)with pathologically confirmed invasive breast cancer.Handcrafted and deep radiomics features were extracted from the MDCT images during the arterial phase.After the feature selection procedures,handcrafted and deep radiomics signatures and the combined model were built using multivariate logistic regression analysis.Performance was assessed by measures of discrimination,calibration,and clinical usefulness in the primary cohort and validated in the validation cohort.Results:The handcrafted radiomics signature had a discriminative ability with a C-index of 0.739[95%confidence interval(95%CI):0.661-0.818]in the primary cohort and 0.695(95%CI:0.609-0.781)in the validation cohort.The deep radiomics signature also had a discriminative ability with a C-index of 0.760(95%CI:0.690-0.831)in the primary cohort and 0.777(95%CI:0.696-0.857)in the validation cohort.The combined model,which incorporated both the handcrafted and deep radiomics signatures,showed good discriminative ability with a C-index of 0.829(95%CI:0.767-0.890)in the primary cohort and 0.809(95%CI:0.740-0.879)in the validation cohort.Conclusions:Handcrafted and deep radiomics features from MDCT images were associated with HER2 status in patients with breast cancer.Thus,these features could provide complementary aid for the radiological evaluation of HER2 status in breast cancer.

Human epidermal growth factor receptor 2 targeted therapy in endometrial cancer:Clinical and pathological perspectives

Endometrial cancer is the most common gynecological cancer in developed countries,and its incidence has increased.The majority of patients with endometrial cancer have an early disease and favorable prognosis;however,a significant proportion of endometrial cancer,which mainly comprises high-grade or type II endometrial cancer such as serous,clear cell,and carcinosarcoma,shows advanced/recurrent disease and dismal prognosis.Novel therapeutic development is required for patients with aggressive endometrial cancers.Recent genomic and immunohistochemical analyses revealed human epidermal growth factor receptor 2(HER2)overexpression/gene amplification in 20%-40%of patients with type II endometrial cancer.Historically,HER2 targeted therapy has been developed for various major cancers,including breast and gastric cancer.Notably,recent advances in HER2 targeted therapy for patients with type II endometrial cancer are also expected to change.Simultaneously,an optimized HER2 test for endometrial cancer as companion diagnostics should be established.In this review,we summarize the recent findings on endometrial cancer,current treatment,optimized HER2 testing,key clinical trials on HER2 targeted therapy,and future directions in aggressive endometrial cancer,including serous carcinoma and carcinosarcoma.

Clinicopathological characteristics of human epidermal growth factor receptor 2-positive Barrett's adenocarcinoma

AIM:To compare the clinicopathological characteristics of human epidermal growth factor receptor 2 (HER2)-positive and HER2-negative Barrett's adenocarcinoma in Japan. METHODS:We performed immunohistochemical analysis of HER2 in 30 samples taken from patients with Barrett's adenocarcinoma and dual color in situ hybridization in cases showing 2+ reactions. We compared the clinicopathological characteristics of HER2-positive and HER2-negative patients.RESULTS:HER2 positivity was identified in 8 (27%) carcinoma samples. We found that HER2 expression was associated with p53 overexpression (100% vs 52.6% in pT1 tumor; 100% vs 54.5% in all stage tumor, P < 0.05) and protruding lesions at the early disease stage. There was no association between the mucin phenotype of the carcinomas and prognosis. HER2 expression and low clinical stage were unexpectedly different between Barrett's adenocarcinoma patients and gastric cancer patients, but the macroscopic features may be associated with earlier diagnosis in these patients. CONCLUSION:Our results suggest that HER2-positive Barrett's adenocarcinomas are associated with p53 overexpression and lesion protrusion at the early disease stage.

Response of human epidermal growth factor receptor 2-positive colorectal cancer to lapatinib monotherapy: A case report

BACKGROUND Human epidermal growth factor receptor 2(HER2)amplification is a molecular driver for a subset of colorectal cancers(CRCs)and one of the major causes of anti-epidermal growth factor receptor(EGFR)treatment failure.Compared to dual anti-HER2 treatments,which have been shown to be effective in HER2-positive metastatic CRC patients,single-agent anti-HER2 therapy is rarely used to treat CRC.CASE SUMMARY Herein,we report a case of RAS/BRAF-wild-type metastatic CRC that was identified as HER2-positive through circulating tumor DNA(ctDNA)testing by next-generation sequencing following the failure of two lines of therapy.Subsequently,the patient was given lapatinib monotherapy that led to a partial response with a progression-free survival of 7.9 mo.Moreover,serial ctDNA detection was used to monitor the efficacy of lapatinib.The aberration of HER2 copy number disappeared when radiographic assessment revealed a partial response.However,a high level of HER2 amplification was detected again at the time of disease progression.Finally,a phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha mutation was identified at the time of tumor progression,which may explain the acquired resistance to lapatinib.CONCLUSION This is the first case report of HER2-positive RAS/BRAF wild-type metastatic CRC patient responding to lapatinib monotherapy.It highlights that ctDNA testing is an effective and feasible approach to evaluate the efficacy of anti-HER2 therapy.

Human epidermal growth factor receptor 2 positive rates in invasive lobular breast carcinoma: The Singapore experience

BACKGROUND Invasive lobular carcinomas(ILC)form 5%-10%of breast cancer and rarely show overexpression of human epidermal growth factor receptor 2(HER2).AIM To describe the prevalence and prognostic factors of HER2 positive(HER2+)ILC in an Asian population.METHODS A retrospective review of patients with ILC seen between January 1985 and March 2018 at various SingHealth medical institutions was conducted.Demographic and clinical data were collected from medical records.We examined clinicopathological characteristics and survival in relation to HER2 status.RESULTS A total of 864 patients were included.Prevalence of HER2 positivity was 10.1%(87 patients).Compared with HER2 negative(HER2-)ILC,HER2+ILC was associated with a higher proportion of estrogen receptor negative(24.4%vs 5.9%,P<0.001),progesterone receptor negative(PR-)(40.2%vs 24%,P=0.002)and grade 3 tumours(Grade 3,29.0%vs 10.2%,P<0.001).Overall survival rate was poorer in patients with HER2+compared to HER2-ILC(56.7%vs 72.9%alive at 10 years;hazard ratio 1.87,95%confidence interval:1.21-2.90,P=0.004).Based on multivariate analysis,negative prognostic factors for overall survival included HER2 positivity,PR negativity,older age,Indian ethnicity and higher tumour stage.CONCLUSION Prevalence of HER2+ILC was 10.1%.HER2+ILC was more likely to have poorer prognostic features such as estrogen receptor negative,PR-and higher tumour grade,and have a poorer survival.

Inetetamab combined with pyrotinib and oral vinorelbine for patients with human epidermal growth factor receptor 2 positive advanced breast cancer:A single-arm phase 2 clinical trial

Background Human epidermal growth factor receptor 2(HER2)-targeted agents have significantly improved the outcomes of patients with HER2-positive breast cancer;however,a large proportion of patients still develop resistance to trastuzumab.In this study,we investigated the efficacy and safety of inetetamab,another anti-HER2 antibody,combined with pyrotinib and oral vinorelbine in patients with HER2-positive advanced breast cancer so as to provide new ideas for the treatment.Methods In this prospective,single-arm,phase 2 trial,patients with HER2-positive advanced breast cancer with disease progression after trastuzumab were recruited.Patients received a combination of inetetamab(loading dose of 8 mg/kg and subsequent doses of 6 mg/kg intravenously once every 3 weeks),pyrotinib(400 mg orally once daily),and vinorelbine(60 mg/m^(2)orally once weekly)until disease progression or intolerable toxicity.The primary endpoint was progression-free survival(PFS).The secondary endpoints included objective response rate(ORR),overall survival(OS),disease control rate(DCR),and safety.Results Between February 13,2022 and December 25,2022,30 patients were screened and enrolled in this study.The median age of the patients at enrollment was 54 years,12 patients(40.0%)had hormone-receptor-positive disease and 23 patients(76.7%)had visceral metastasis.The median PFS was 8.63 months(95%confidence interval[CI]4.15-13.12 months).The median OS was not reached.The ORR was 53.3%(16/30)and the DCR was 96.7%(29/30).The most common Grade III/IV adverse events were leukopenia(n=5,16.7%),neutropenia(n=4,13.3%),and diarrhea(n=3,10%).No treatment-related serious adverse events or deaths occurred.Conclusions The combination regimen of inetetamab,pyrotinib,and oral vinorelbine showed encouraging efficacy and favorable safety in patients with HER2-positive advanced breast cancer and could be considered as an alternative treatment option for the patients.

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.

Comparison of immunohistochemistry with fluorescence in situ hybridization in determining the human epidermal growth factor receptor 2 status of breast cancer specimens： a multicenter study of 3149 Chinese patients

Background Accurate detection of human epidermal growth factor receptor 2 （HER2） expression and gene amplification is crucial for the application of HER2-specific therapy and for evaluating the response of patients with breast cancer.A uniform and standard procedure of immunohistochemistry （IHC） and fluorescence in situ hybridization （FISH） needs to be established for evaluating the HER2 status in breast cancer tissues for the treatment of patients with real HER2-positive tumors.The present multicenter study was aimed to examine the HER2 status in breast cancer specimens from Chinese patients using both IHC and FISH methods.Methods A multicenter study was performed on the HER2 status in 3 149 breast cancer specimens from different ethnic populations and areas in China by IHC and FISH assays.The potential association of HER2 status with demographic and clinical characteristics was analyzed.Results The positive rates for HER2 over-expression and HER2 amplification were 23.3％ and 27.5％ in this study,respectively.The concordance between IHC and FISH was 71.2％ （K=0.494,P ＜0.001）.Furthermore,72.9％ of specimens with IHC 2＋ were negative to FISH.The discordance rates among laboratories were from 5％ to 28％ for IHC and 1％ to 16％ for FISH.HER2 amplification was associated significantly with advanced tumor stage （Ⅲ or Ⅳ,P=0.002）,large tumor size （＞5 cm,P=0.002）,moderate and poor histological grades （P ＜0.0001）,post-menopause （P ＜0.0001）,ER-PR-（P=0.002）,and having ＞4 lymph nodes affected （P ＜0.0001） in this population.The positive rates of HER2 amplification in specimens from Man and Hui Chinese were significantly higher than that in other Chinese populations.There are slightly higher positive rates of HER2 expression and amplification in Chinese patients with breast cancer.Conclusion These findings may provide new insights into understanding the epidemiological features of HER2 expression and amplification,and may be valuable for clinical practice.

Management of breast cancer brain metastases: Focus on human epidermal growth factor receptor 2-positive breast cancer

After the introduction of trastuzumab, a monoclonal antibody that binds to human epidermal growth factor receptor 2 (HER2), the overall survival (OS) among patients with HER2-positive breast cancer has been substantially improved. However, among these patients, the incidence of brain metastases (BM) has been increasing and an increased proportion of them have died of intracranial progression, which makes HER2-positive breast cancer brain metastases (BCBM) a critical issue of concern. For local control of limited BM, stereotactic radiosurgery (SRS) and surgical resection are available modalities with different clinical indications. Postoperative or preoperative radiation is usually delivered in conjunction with surgical resection to boost local control. Adjuvant whole-brain radiotherapy (WBRT) should be deferred for limited BM because of its impairment of neurocognitive function while having no benefit for OS. Although WBRT is still the standard treatment for local control of diffuse BM, SRS is a promising treatment for diffuse BM as the technique continues to improve. Although large molecules have difficulty crossing the blood brain barrier, trastuzumab-containing regimens are critical for treating HER2-positive BCBM patients because they significantly prolong OS. Tyrosine kinase inhibitors are more capable of crossing into the brain and they have been shown to be beneficial for treating BM in HER2-positive patients, especially lapatinib combined with capecitabine. The antiangiogenic agent, bevacizumab, can be applied in the HER2-positive BCBM scenario as well. In this review, we also discuss several strategies for delivering drugs into the central nervous system and several microRNAs that have the potential to become biomarkers of BCBM.

Human epidermal growth factor receptor type 2 protein expression in Chinese metastatic prostate cancer patients correlates with cancer specific survival and increases after exposure to hormonal therapy

Aim： To investigate human epidermal growth factor receptor type 2 （HER2） protein expression and gene amplification in Chinese metastatic prostate cancer patients and their potential value as prognostic factors. Methods： Immunohistochemistry （IHC） was performed to investigate HER2 protein expression in prostate biopsy specimens from 104 Chinese metastatic prostate cancer patients. After 3-11 months of hormonal therapy, 12 patients underwent transurethral resection of the prostate （TURP）. HER2 protein expression of TURP specimens was compared with that of the original biopsy specimens. Of these, 10 biopsy and 4 TURP specimens with HER2 IHC staining scores ≥ 2＋ were investigated for HER2 gene amplification status by fluorescent in situ hybridization （FISH）. Results： Of the 104 prostate biopsy specimens, HER2 protein expression was 0, 1＋, 2＋ and 3＋ in 49 （47.1%）, 45 （43.3%）, 8 （7.7%） and 2 （1.9%） cases, respectively. There was a significant association between HER2 expression and Gleason score （P = 0.026）. HER2 protein expression of prostate cancer tissues increased in 33.3% of patients after hormonal therapy. None of the 14 specimens with HER2 IHC scores 〉 2＋ showed HER2 gene amplification. Patients with HER2 scores 〉 2＋ had a significantly higher chance of dying from prostate cancer than those with HER2 scores of 0 （P = 0.004） and 1＋ （P = 0.034）. Multivariate Cox regression analysis showed that HER2 protein expression intensity was an independent predictor of cancer-related death （P = 0.039）. Conclusion： An HER2 IHC score 〉 2＋ should be defined as HER2 protein overexpression in prostate cancer. Overexpression of HER2 protein in cancer tissue might suggest an increased risk of dying from prostate cancer. HER2 protein expression increases in some individual patients after hormonal therapy.

Quercetin inhibits truncated isoform of dopamine-and cAMP-regulated phosphoprotein as adjuvant treatment for trastuzumab therapy resistance in HER2-positive breast cancer

Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2(HER2)-positive(HER2+)breast cancer(BC).The truncated isoform of dopamine-and cAMPregulated phosphoprotein(t-DARPP)has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression.To evaluate the t-DARPP expression in BC,paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+BC tumor tissues.We established 2 patient-derived xenografts(PDX)mice models to test the efficacy of trastuzumab,named model 1(non-responder)and model 2(responder).t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays.Instead,there is no response from the responder.Furthermore,mechanistic studies using transwell and western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins,enhance p95-HER2 expression and promote cell migration.We found that quercetin effectively reduced t-DARPP expression in HER2+BC cells.In t-DARPP ShRNA-suppressed cells,quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest.In conclusion,the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+BC patients has the potential as a biomarker for mitigating drug resistance.

Genomic profiling of colorectal cancer in large-scale Chinese patients:amplification and somatic mutations in ERBB2

Objectives:Human epidermal growth factor receptor 2(HER2)-targeted therapies have demonstrated potential benefits for metastatic colorectal cancer(mCRC)patients with HER2 amplification,but are not satisfactory in cases of HER2 mutant CRCs.Methods:Consequently,further elucidation of amplifications and somatic mutations in erythroblastic oncogene B-2(ERBB2)is imperative.Comprehensive genomic profiling was conducted on 2454 Chinese CRC cases to evaluate genomic alterations in 733 cancer-related genes,tumor mutational burden,microsatellite instability,and programmed death ligand 1(PD-L1)expression.Results:Among 2454 CRC patients,85 cases(3.46%)exhibited ERBB2 amplification,and 55 cases(2.24%)carried ERBB2 mutation.p.R678Q(28%),p.V8421(24%),and p.S310F/Y(12%)were the most prevalent of the 16 detected mutation sites.In comparison to the ERBB2 altered(alt)group,KRAS/BRAF mutations were more prevalent in ERBB2 wild-type(wt)samples(ERBB2wt vs.ERBB2alt,KRAS:50.9%vs.25.6%,p<0.05;BRAF:8.5%vs.2.3%,p<0.05).32.7%(18/55)of CRCs with ERBB2 mutation exhibited microsatellite instability high(MSI-H),while no cases with HER2 amplification displayed MSI-H.Mutant genes varied between ERBB2 copy number variation(CNV)and ERBB2 single nucleotide variant(SNV);TP53 alterations tended to co-occur with ERBB2 amplification(92.3%)as opposed to ERBB2 mutation(58.3%).KRAS and PIK3CA alterations were more prevalent in ERBB2 SNV cases(KRAS/PIK3CA:45.8%/31.2%)compared to ERBB2 amplification cases(KRAS/PIK3CA:14.1%/7.7%).Conclusion:Our study delineates the landscape of HER2 alterations in a large-scale cohort of CRC patients from China.These findings enhance our understanding of the molecular features of Chinese CRC patients and offer valuable implications for further investigation.

Disitamab vedotin combined with apatinib in gastric cancer: A case report and review of literature

BACKGROUND In patients with human epidermal growth factor receptor 2(HER2)-overex-pressing gastric cancer(GC),the combination of HER2 targeting and a standard first-line chemotherapy regimen has been demonstrated to significantly improve their prognosis.However,in a proportion of patients,cancer progresses within a short period of time,and there is currently no standard treatment after disease progression.CASE SUMMARY This study presents a case of a 51-year-old male with advanced GC who un-derwent radical resection(Billroth type II subtotal gastrectomy and gastrojejun-ostomy)and resection of liver metastases.Immunohistochemical staining revealed a HER2 score of 2+,a dMMR status,and a Ki67 proliferation index of 30%to 40%.The gene test results indicated the presence of ERBB2 amplification and a PD-L1 expression level of less than 5%.Since December 2021,the patient has experienced disease progression during both first-line(two cycles of KN026 combined with KN046)and second-line(five cycles of nivolumab combined with trastuzumab and SOX chemotherapy)treatment regimens.The patient's prognosis following the first and second lines of treatment was unfavorable,with pro-gression occurring in a relatively short time.For third-line therapy,disitamab vedotin(RC48)plus apatinib was used.At the time of this report,the patient had achieved a progression-free survival(PFS)of 25.8 months,which exceeded the median survival time for patients with advanced GC.CONCLUSION Despite the unfavorable prognosis associated with advanced GC,the imple-mentation of personalized treatment approaches may still prove beneficial for select patients.In patients with HER2-positive GC with extensive metastatic involvement,the use of the HER2-targeted combination with apatinib has demonstrated the potential to prolong both PFS and overall survival.

Targeted approaches for HER2 breast cancer therapy: News from nanomedicine?

About 30% of human breast cancers are human epidermal growth factor receptor 2 （HER2）＋. This particular biological portrait is characterized by the overexpression of HER2 receptor with the subsequent deregulation of downstream pathways, which control cellular survival and proliferation. The most effective treatment for HER2＋ cancer is represented by therapy with HER2-targeted agents. Anti-HER2 therapy dramatically improves clini-cal outcomes, although it shows some limitations in achieving a proper treatment. These drawbacks of HER2-targeted therapy may be overcome with the develop-ment of HER2-targeted drug delivery nanodevices. These nanoparticles possess an internal three-dimensional com-partimentalization, which allows to combine the specifc target recognition with their capability to act as a drug reservoir for the selective delivery of chemotherapics to tumor sites. Moreover, nanoparticles useful in photo-thermal ablation or in photodynamic therapy have been functionalized in order to match specifcity in tumor cell recognition and suitable chemical properties. Here, we summarize the state of the art concerning the HER2＋ breast cancer and anti-HER2 therapy, in particular deep-ening the contribution of the nanomedicine. Description of preclinical studies performed with HER2-targeted nanoparticles for HER2＋ breast cancer therapy will be preceded by an overview on HER2-targeting molecules and nano-conjugation strategies. Further investigation will be necessary to introduce these nano-drugs in clinical prac-tice; however promising results encourage an upcoming translation of this research for the next future.