Rational Treatment Option Research Articles

TOPORS E3 ligase mediates resistance to hypomethylating agent cytotoxicity in acute myeloid leukemia cells

Hypomethylating agents (HMAs) are frontline therapies for Myelodysplastic Neoplasms (MDS) and Acute Myeloid Leukemia (AML). However, acquired resistance and treatment failure are commonplace. To address this, we perform a genome-wide CRISPR-Cas9 screen in a human MDS-derived cell line, MDS-L, and identify TOPORS as a loss-of-function target that synergizes with HMAs, reducing leukemic burden and improving survival in xenograft models. We demonstrate that depletion of TOPORS mediates sensitivity to HMAs by predisposing leukemic blasts to an impaired DNA damage response (DDR) accompanied by an accumulation of SUMOylated DNMT1 in HMA-treated TOPORS-depleted cells. The combination of HMAs with targeting of TOPORS does not impair healthy hematopoiesis. While inhibitors of TOPORS are unavailable, we show that inhibition of protein SUMOylation with TAK-981 partially phenocopies HMA-sensitivity and DDR impairment. Overall, our data suggest that the combination of HMAs with inhibition of SUMOylation or TOPORS is a rational treatment option for High-Risk MDS (HR-MDS) or AML.

Oral antidiabetic therapy versus early insulinization on glycemic control in newly diagnosed type 2 diabetes patients: a retrospective matched cohort study

Our study aims to compare the efficacy of oral antidiabetic therapy to early insulinization on glycemic control among newly diagnosed type 2 diabetes patients in real-world clinical practice. A retrospective cohort study conducted at a medical center in Taiwan analyzed 1256 eligible patients from January 2007 to December 2017. Propensity score matching resulted in well-balanced groups of 94 patients each in the oral antidiabetic drug (OAD) and early insulinization cohorts. Glycemic outcomes were assessed in both groups. Patients exclusively using OAD showed consistently lower glycated hemoglobin (HbA1c) levels at 3, 12, 24, and 36 months compared to insulin users. At later periods, 77.7% of OAD users achieved glycemic control versus 64.9% of insulin users, with a marginally significant difference. Subgroup analyses suggested a trend favoring well-controlled diabetes in the OAD group, though not statistically significant. Our study finds oral antidiabetic therapy is not inferior to early insulinization for glycemic control in newly diagnosed type 2 diabetes patients, irrespective of initial HbA1c levels. This supports oral therapy as a rational treatment option, even in cases with elevated HbA1c at diagnosis.

MDB-13. GERMLINEELP1 DEFICIENCY SENSITIZES CEREBELLAR GRANULE NEURON PROGENITORS TO SHH MEDULLOBLASTOMA

Abstract BACKGROUND Germline loss-of-function (LOF) variants in Elongator complex protein 1 (ELP1) are the most prevalent predisposing genetic events observed in medulloblastoma (MB), accounting for 30% of the Sonic Hedgehog 3 subtype (SHH-3). Molecularly, ELP1-associated SHH-MBs acquire somatic PTCH1 mutations in >80% of cases, and universal loss-of-heterozygosity of the wild-type ELP1 and PTCH1 alleles through loss of chromosome-arm 9q, resulting in their biallelic inactivation. Notably, germline ELP1 LOF occurs mutually exclusive with somatic/germline TP53 mutations in the SHH-3 subtype, suggesting that genetic perturbation of either ELP1 or TP53 may promote similar tumorigenic consequences in cerebellar granule neuron progenitors (GNPs), the accepted cellular origin of SHH-MB. Despite these findings, the molecular, biochemical, and cellular mechanism(s) by which ELP1-deficiency provokes malignant pathogenesis remain unknown. In this study, we sought to close this knowledge gap and functionally determine why children harboring pathogenic ELP1 germline variants are at an increased risk of developing SHH-MB. METHODS Mice were genetically engineered to mimic heterozygous Elp1 LOF (Elp1HET). We studied the effect of Elp1 LOF in GNPs using a combination of molecular profiling, immunophenotyping, and cellular assays. RESULTS GNPs from Elp1HET mice exhibited a spectrum of molecular and biochemical hallmarks of malignant transformation including increased DNA replication stress, DNA damage, accelerated cell cycle progression, and stalled differentiation. Orthotopic transplantation of Elp1HET GNPs engineered to harbor somatic Ptch1 inactivation yielded SHH-MB-like tumors with compromised p53 signaling, providing an explanation for the specificity of ELP1-associated tumors in SHH-3, and their exclusivity with TP53-mutant tumors. Treatment of ELP1-mutant patient-derived xenografts with an FDA-approved MDM2 inhibitor reactivated p53-dependent apoptosis and extended survival. CONCLUSIONS Collectively, our findings functionally substantiate the role of ELP1 deficiency in predisposition to SHH-3 MB and nominate therapeutic strategies to overcome p53 inhibition as a rational treatment option.

Clinical features and treatment of heterotopic pancreas in children: a multi-center retrospective study

ObjectiveHeterotopic pancreas, an uncommon condition in children, can present with diagnostic and treatment challenges. This study aimed to evaluate the clinical features and treatment options for this disorder in pediatric patients.MethodsWe conducted a retrospective analysis, including patients diagnosed with heterotopic pancreas at four tertiary hospitals between January 2000 and June 2022. Patients were categorized into symptomatic and asymptomatic groups based on clinical presentation. Clinical parameters, including age at surgery, lesion size and site, surgical or endoscopic approach, pathological findings, and outcome, were statistically analyzed.ResultsThe study included 88 patients with heterotopic pancreas. Among them, 22 were symptomatic, and 41 were aged one year or younger. The heterotopic pancreas was commonly located in Meckel’s diverticulum (46.59%), jejunum (20.45%), umbilicus (10.23%),ileum (7.95%), and stomach (6.82%). Sixty-six patients had concomitant diseases. Thirty-three patients had heterotopic pancreas located in the Meckel’s diverticulum, with 80.49% of cases accompanied by gastric mucosa heterotopia (GMH). Patients without accompanying GMH had a higher prevalence of heterotopic pancreas-related symptoms (75%). Treatment modalities included removal of the lesions by open surgery, laparoscopic or laparoscopic assisted surgery, or endoscopic surgery based on patient’s age, the lesion site and size, and coexisting diseases.ConclusionsOnly one-fourth of the patients with heterotopic pancreas presented with symptoms. Those located in the Meckel’s diverticulum have commonly accompanying GMH. Open surgical, laparoscopic surgical or endoscopic resection of the heterotopic pancreas is recommended due to potential complications. Future prospective multicenter studies are warranted to establish rational treatment options.

Rational treatment options for T1/2N0M0 squamous cell carcinoma of the anal canal: a population-based study combined with external validation.

Treatment options for T1/2N0M0 anal squamous cell carcinoma include chemotherapy, radiotherapy, chemoradiotherapy, and local excision, although the optimal treatment method has not been determined. The National Cancer Institute Surveillance, Epidemiology and Results database was used to search and screen 1465 patients with cT1/2N0M0 anal squamous cell carcinoma who were clinically diagnosed between 2004 and 2016. Survival analysis was performed using the Kaplan-Meier method and log-rank test. Cox proportional hazards regression analysis was performed to screen independent prognostic factors and build a nomogram survival prediction model. According to the risk score, patients were divided into low, medium, and high risk groups using X-tile software. Age, sex, grade and cT stage were identified as independent prognostic factors for cT1/2N0M0 anal squamous cell carcinoma and were included in the nomogram to construct a prediction model. The C-index of the model was 0.770 [95% confidence interval (CI), 0.693-0.856], which was higher than the C-index of T stage 0.565 (95% CI, 0.550-0.612). Low-risk patients benefited from local resection, moderate-risk patients benefited from radiotherapy, and high-risk patients benefited from radiotherapy or chemoradiotherapy. This was confirmed using external validation data from the center. The nomogram developed in this study effectively and comprehensively evaluated the prognosis of patients with cT1/2N0M0 squamous cell carcinoma of the anal canal. Local excision is recommended for low risk patients, radiotherapy for moderate-risk patients, and radiotherapy or chemoradiotherapy for high-risk patients.

Single-Cell Sequencing Illuminates Thymic Development: An Updated Framework for Understanding Thymic Epithelial Tumors.

Thymic epithelial tumors (TETs) are rare tumors for which treatment options are limited. The ongoing need for improved systemic therapies reflects a limited understanding of tumor biology as well as the normal thymus. The essential role of the thymus in adaptive immunity is largely effected by its epithelial compartment, which directs thymocyte (T-cell) differentiation and immunologic self-tolerance. With aging, the thymus undergoes involution whereby epithelial tissue is replaced by adipose and other connective tissue, decreasing immature T-cell production. Against this natural drive toward involution, a fraction of thymuses will instead undergo oncologic transformation, leading to the formation of TETs, including thymoma and thymic carcinoma. The rarity of these tumors restricts investigation of the mechanisms of tumorigenesis and development of rational treatment options. To this end, the development of technologies which allow deep molecular profiling of individual tumor cells permits a new window through which to view normal thymic development and contrast the malignant changes that result in oncogenic transformation. In this review, we describe the findings of recent illuminating studies on the diversity of cell types within the epithelial compartment through thymic differentiation and aging. We contextualize these findings around important unanswered questions regarding the spectrum of known somatic tumor alterations, cell of origin, and tumor heterogeneity. The perspectives informed by single-cell molecular profiling offer new approaches to clinical and basic investigation of thymic epithelial tumors, with the potential to accelerate development of improved therapeutic strategies to address ongoing unmet needs in these rare tumors.

Abstract B036: Mutational landscape and genetic feature of gastric adenocarcinoma in multiple Chinese ethnicities

Abstract Gastric cancer is a heterogeneous malignancy and the fifth most common cancer worldwide, with 44% of cases occurring in China. Elucidation of genetic subtypes may improve gastric cancer treatment planning. Matched tumour and peritumoural (non-malignant gastric mucosa) tissue samples were collected from 306 Chinese patients and subjected to whole-exome sequencing (WES). The results were used to produce a Chinese Gastric Cancer Genome Atlas (CGCGA). Patients from nine Chinese ethnic groups (Han, Zhuang, Hui, Uygur, Yi, Tibetan, Mongolian, Bai, and Kazakh), representing 95% of the Chinese population were included. Systematic comparison of CGCGA data with TCGA (The Cancer Genome Atlas) data, in which 437 gastric cancer cases are represented, showed that genomic alteration signatures in the present cohort differed markedly from those reported for Western cohorts. TP53 and FAT1 deletions were more frequent (35% vs. 0%) while ARID1A deletions (13% vs. 25%), MYC oncogene amplifications (53% vs. 70%), and SMAD4 deletions (34% vs. 46%) were less frequent in our CGCGA data than in the TCGA data. TRIM49B mutation was associated with worse survival. Thus, TRIM49B was identified as a novel oncogene. The Zhuang ethnic group had a much higher tumour mutation burden (TMB) than the other ethnic groups. Typically, tumours from Han group had microsatellite stability, whereas those from the other groups had microsatellite instability (MSI). We further propose a molecular classification of four gastric cancer subtypes that are associated with distinct survival outcomes: TP53 mutation positive (TP53+)/TTN_missense+; TP53+/TTN_missense–; TP53–/TTN_missense+, and TP53–/TTN_missense–. Our study established a comprehensive gastric cancer genome atlas in China and underscored the importance of considering population context in genomic mapping and rational treatment options for the disease. Citation Format: Liang Zong. Mutational landscape and genetic feature of gastric adenocarcinoma in multiple Chinese ethnicities [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr B036.

Metastatic castration-resistant prostate cancer-what are rational sequential treatment options?

In advanced prostate cancer, disease progression during ongoing androgen deprivation therapy (ADT) is referred to as castration-resistant prostate cancer (CRPC). Various therapeutic modalities are available for its treatment, including endocrine therapy, chemotherapy, poly (ADP-ribose) polymerase [PARP] inhibition, radionuclide therapy, and radioligand therapy. This review outlines practical aspects and considerations regarding treatment sequencing in mCRPC. The findings are based on existing prospective phase3studies that have demonstrated clinically relevant and statistically significant benefits in radiographically progression-free and/or overall survival. Sequential therapy, aside from numerous patient-specific factors, depends on the treatment patients received in the hormone-sensitive prostate cancer (mHSPC) setting. Following pretreatment with ADT alone or ADT plus docetaxel in the mHSPC context, additional endocrine therapy is the standard approach. In the event of progression under combined endocrine therapy initiated in the mHSPC setting, docetaxel currently serves as the standard for the majority of patients. Patients who received triplet therapy as apretreatment in the mHSPC scenario can be treated with radioligand therapy or second-line chemotherapy. Various active and well-tolerated treatment options are available for patients with metastatic castration-resistant prostate cancer (mCRPC). The choice of therapy is primarily determined by previous treatments, but many other individual factors are also taken into consideration.

Activity of novel β-lactam/β-lactamase inhibitor combinations against serine carbapenemase-producing carbapenem-resistant Pseudomonas aeruginosa.

Antimicrobial resistance in Pseudomonas aeruginosa is complex and multifaceted. While the novel β-lactamase inhibitors (BLIs) avibactam, relebactam and vaborbactam inhibit serine-based β-lactamases, the comparative potency of the novel β-lactam (BL)/BLI combinations against serine carbapenemase-producing P. aeruginosa is unknown. To compare the in vitro activity of ceftazidime/avibactam, ceftazidime, imipenem/relebactam, imipenem, meropenem/vaborbactam and meropenem against serine β-lactamase-producing P. aeruginosa. Carbapenem-resistant P. aeruginosa were collated through the Enhancing Rational Antimicrobials against Carbapenem-resistant P. aeruginosa (ERACE-PA) Global Surveillance. Isolates positive for serine-based carbapenemases were assessed. MICs were determined by broth microdilution to each novel BL/BLI and BL alone. GES was the most common carbapenemase identified (n = 59) followed by KPC (n = 8). Ceftazidime/avibactam had MIC50/MIC90 values of 4/8 mg/L and 91% of isolates were susceptible. Conversely, ceftazidime alone was active against only 3% of isolates. The MIC50/MIC90 of imipenem/relebactam were 16/>16 mg/L and 13% of all isolates were defined as susceptible. Of the KPC-producing isolates, 38% were susceptible to imipenem/relebactam, compared with 0% to imipenem. The meropenem/vaborbactam MIC50/MIC90 were >16/>16 mg/L, and 6% of isolates were susceptible, which was similar to meropenem alone (MIC50/90, >8/>8 mg/L; 3% susceptible) suggesting the addition of vaborbactam cannot overcome co-expressed, non-enzymatic resistance mechanisms. Among the novel BL/BLIs, ceftazidime/avibactam displayed better in vitro activity and thus is a rational treatment option for serine carbapenemase-harbouring P. aeruginosa. While imipenem/relebactam displayed some activity, particularly against isolates with blaKPC, meropenem/vaborbactam exhibited poor activity, with MICs similar to meropenem alone.

Distinct Mechanisms of Resistance to CDK4/6 Inhibitors Require Specific Subsequent Treatment Strategies: One Size Does Not Fit All.

Cyclin-dependent kinase (CDK) 4/6 inhibitors have transformed the treatment landscape of patients with hormone receptor-positive breast cancers. However, despite improvements in clinical outcomes, the approximately 70% of patients with tumors that are not intrinsically resistant to a CDK4/6 inhibitor still ultimately acquire resistance, which leads to a dilemma for clinicians when deciding which treatment to offer patients when they demonstrate disease progression on a CDK4/6 inhibitor. As such, many groups have sought to understand the mechanisms of resistance to CDK4/6 inhibitors, mostly focusing on genetic alterations associated with resistance. Though several recurrent mutations have been described, they are not consistent enough to guide clinical practice or generate novel rational treatment options. Two recent publications have used transcriptomic analysis to unravel distinct mechanisms driving resistance to individual CDK4/6 inhibitors and in doing so have identified biomarkers that could potentially help identify the next course of treatment for patients following disease progression.

MDB-23. ELP1 GERMLINE DEFICIENCY SENSITIZES THE GRANULE NEURON LINEAGE TO SHH MEDULLOBLASTOMA AND EXPOSES NOVEL THERAPEUTIC VULNERABILITIES

Abstract Germline loss-of-function (LOF) variants in Elongator complex protein 1 (ELP1) are the most prevalent predisposing genetic events in childhood medulloblastoma (MB). ELP1 germline carriers develop SHH-MBs that exhibit coincident somatic PTCH1 mutations and universal loss-of-heterozygosity of the remaining ELP1 allele through chromosome 9q deletion. The molecular, biochemical, and cellular mechanisms by which germline ELP1/Elongator deficiency contribute to SHH-MB tumorigenesis remain largely unknown. Herein, we report that mice engineered to mimic germline Elp1 LOF (i.e., Elp1HET) seen in SHH-MB patients exhibit hallmark features of premalignancy events in cycling cerebellar granule neuron progenitors (GNPs), the lineage-of-origin for SHH-MB. Compared to wild-type counterparts, Elp1HET GNPs exhibit increased replication stress-associated DNA damage, homologous recombination-associated genomic instability, accelerated cell cycle kinetics, reduced p53-dependent apoptosis in response to genotoxic stress, and slowed differentiation. Orthotopic transplantation of Elp1HET GNPs harboring somatic Ptch1 inactivation into the cerebella of immunocompromised mice promotes onset of SHH-MB tumors with incomplete penetrance that exhibit reduced p53 transcriptional activity through a currently unknown mechanism(s). Concomitant Elp1 and Ptch1 gene targeting in p53-null GNPs reproduces highly penetrant cerebellar tumors recapitulating the molecular and phenotypic features of ELP1-associated SHH-MB. Finally, reactivation of the p53 pathway through preclinical treatment with an MDM2 inhibitor promotes cell death and prolongs the survival of patient-derived xenograft tumor (PDX) models harboring deleterious ELP1 mutations. Together, our findings reveal that germline Elp1 LOF heightens genomic instability and malignant transformation in cycling GNPs, providing a mechanistic model for the subgroup-restricted pattern of predisposition associated with pathogenic ELP1 germline carriers. These results provide essential mechanistic insight into the molecular and cellular basis of SHH-MB predisposition driven by ELP1 LOF and nominate therapies that overcome p53 pathway inhibition as a rational treatment option for affected children.

Successful percutaneous transhepatic lymphangiography and embolization for intractable hepatic lymphorrhea after laparoscopic distal gastrectomy: a case report

BackgroundHepatic lymphorrhea is a rare and serious complication of surgery for digestive tract cancers and is thought to occur as a result of lymph node dissection of the hepatoduodenal ligament. This complication results in the accumulation of lymphatic fluid, which may in turn lead to nutritional disorders, immune deficiency, and circulation insufficiency. However, there is currently no standard strategy for treating this condition.Case presentationA 49-year-old woman with alcoholic liver damage underwent laparoscopic distal gastrectomy with lymph node dissection for early gastric cancer. Abundant ascites persisted postoperatively, and the fluid was suspected to indicate hepatic lymphorrhea. The patient was re-admitted on postoperative day 26 due to the onset of a brain infarction caused by dehydration. Various conservative treatments for hepatic lymphorrhea were ineffective. She underwent percutaneous transhepatic lymphangiography and embolization on postoperative day 81, with obvious effect. Computed tomography images demonstrated complete disappearance of ascites.ConclusionsPostoperative hepatic lymphorrhea is a rare and serious complication of radical surgery for digestive tract cancers. The current case suggests that percutaneous transhepatic lymphangiography and embolization may be a rational treatment option when conservative treatments fail.

Oligometastatic disease and visceral resections in advanced malignant melanoma: a propensity-matched analysis

PurposeMalignant melanoma is among the tumours with the highest increase in incidence of solid tumours in Germany. While most patients are diagnosed at an early stage and show a good prognosis, advanced stages of malignant melanoma are accompanied with a poor prognosis and limited treatment options. Comparable to other tumour entities, the resection of visceral metastases could lead to a better prognosis. Supplementary, the subgroup of oligometastatic patients might benefit from surgical therapy to a greater extent.MethodsThis retrospective study analysed 351 patients treated between 2006 and 2017 at the University Hospital of Cologne. A total of 121 patients showed visceral metastases, with which we compared patients with a diffuse tumour spread to patients in an oligometastatic state. Furthermore, we evaluated the effect of visceral resection of oligometastatic, malignant melanoma.ResultsOur analysis showed that patients with an oligometastatic malignant melanoma had a significantly better prognosis than patients with a diffuse pattern of metastases, if they showed visceral metastases. Furthermore, the resection of visceral metastases leads to a significant gain in median overall survival time (13.6 vs. 34.2 months) and in progression-free survival (9.6 vs. 3.8 months).ConclusionThe resection of visceral metastases is a rational treatment option in advanced malignant melanoma. Although our study is limited by a small cohort of patients (n = 18), we believe that the resection of visceral metastases will be fundamental in the treatment of malignant melanoma. In particular, patients in an oligometastatic stage could be an eligible group for surgical treatment.

A review of 14 cases of perianal Paget’s disease: characteristics of anorectal cancer with pagetoid spread

BackgroundPerianal Paget’s disease (PPD) is an intraepithelial invasion of the perianal skin and is frequently associated with underlying anorectal carcinoma. The relatively rare nature of this disease has made it difficult to develop treatment recommendations. This study aims to analyze the clinical and pathological features of perianal Paget’s disease (PPD) and to explore rational treatment options and follow-up for this disease.MethodsThe National Cancer Center Hospital database was searched for all cases of perianal Paget’s disease diagnosed between 2006 and 2021. In the 14 patients identified, we reviewed the diagnosis, management, and outcomes of adenocarcinoma with pagetoid spread, including suspected or recurrent cases.ResultsAll 14 cases met the inclusion criteria. The median follow-up period after diagnosis was 4.5 (range, 0.1–13.0) years. Pagetoid spread before initial treatment was suspected in 12 cases (85.7%). Underlying rectal cancer was identified in 6 cases, and no primary tumor was detected in the other 6 cases. Seven patients had recurrent disease, with the median time to recurrence of 34.6 (range, 19.2–81.7) months. The time to the first relapse was 3 months, and that to the second relapse was 6 months. The overall 5-year survival rate was 90.0%.ConclusionsEndoscopic and radiologic evaluation, as well as immunohistologic examination, should be performed. is to differentiate PPD with and without underlying anorectal carcinoma. The time to first recurrence varies widely, and long-term and regular follow-up for more than 5 years is considered necessary for local recurrence and distant metastasis.

Switching Antipsychotic Medications in People with Schizophrenia: A 4-Year Naturalistic Study.

Although generally effective in ameliorating the core manifestations of schizophrenia, antipsychotics (APs) may lead to only suboptimal responses or may be associated with a variety of treatment-related adverse events which require additional treatment strategies. Under such clinical circumstances, switching APs represents a rational treatment option. The present study aimed to identify the variables that predict AP switch and to quantify the frequency of this phenomenon in people with schizophrenia in real-life. A secondary analysis was conducted on the data collected at baseline and at a 4-year follow-up from a large sample of community-dwelling Italian people with schizophrenia. Demographic and clinical variables as well as information about AP treatment were recorded at two time points. Over the 4-year period, 34.9% of the 571 participants switched the AP; in particular, 8.4% of participants switched from first-generation APs (FGAs) to second-generation APs or vice versa, while 8.2% of them switched to clozapine. Logistic regression models showed that combination of APs at baseline was negatively associated with AP switch, while treatment with FGAs and the presence of extrapyramidal symptoms at baseline were associated with AP class switch. Although the aim of the present study was not to assess predictors of clinical relapse in people with schizophrenia, we might speculate that switching APs represents a surrogate indicator of treatment failure in some patients and could lead into relapse, which is a costly aspect of schizophrenia management in both economic and human terms. The sooner such a negative outcome can be predicted and managed, the sooner the treatment can be optimized to avoid it.

Aggressive unifocal bone Langerhans cell histiocytosis with soft tissue extension both responsive to radiotherapy: a case report

BackgroundLangerhans cell histiocytosis (LCH) is a rare haematological neoplasm characterized by the accumulation of CD1a+, CD207/Langerin+ histiocytes within inflammatory lesions. LCH can involve any organ, but osteolytic bone lesions are most often encountered. Unifocal bone lesions may regress spontaneously after a thick needle biopsy has been taken.Case presentationIn this case report, we describe the initial presentation of a single BRAFV600E mutated osteolytic LCH lesion in the left proximal humerus of a 46-year-old previously healthy woman. Despite multiple surgical interventions, she unexpectedly experienced progressive disease manifestation with significant soft tissue extension to the surrounding musculature, subcutis and epidermis. Because the disease manifestation remained loco-regional, radiotherapy (RT) (total dose of 20 Gy in 10 fractions) was initiated.ConclusionThe patient achieved a complete remission without any side effects. This case highlights that RT is a rational and relative mild local treatment option for patients with aggressive LCH affecting the bone and surrounding soft tissue.

Hypoxia in Aging and Aging-Related Diseases: Mechanism and Therapeutic Strategies

As the global aging process continues to lengthen, aging-related diseases (e.g., chronic obstructive pulmonary disease (COPD), heart failure) continue to plague the elderly population. Aging is a complex biological process involving multiple tissues and organs and is involved in the development and progression of multiple aging-related diseases. At the same time, some of these aging-related diseases are often accompanied by hypoxia, chronic inflammation, oxidative stress, and the increased secretion of the senescence-associated secretory phenotype (SASP). Hypoxia seems to play an important role in the process of inflammation and aging, but is often neglected in advanced clinical research studies. Therefore, we have attempted to elucidate the role played by different degrees and types of hypoxia in aging and aging-related diseases and their possible pathways, and propose rational treatment options based on such mechanisms for reference.

Mutation-tailored treatment selection in non-small cell lung cancer patients in daily clinical practice

ObjectivesThe number of targeted drugs in non-small cell lung cancer (NSCLC) is ever-expanding and requires testing of an increasing number of predictive biomarkers. We present a comprehensive real-world evaluation of molecular testing and treatment selection in stage IV NSCLC patients in the Netherlands from 2017 to 2019. Materials and methodsMolecular pathology reports of NSCLC patients were collected from the Dutch Pathology Registry in time intervals between Oct-2017 and April-2019 (N = 5,038 patients) to study diagnostic yield. Linkage between the Dutch Pathology Registry and the Netherlands Cancer Registry enabled studying molecular testing rates for stage IV NSCLC initially diagnosed in 2017-Q4 (N = 1,193) and application of targeted therapy in stage IV NSCLC patients with potentially druggable alterations reported between Oct-2017 and June-2018 (N = 401). ResultsPredictive molecular testing was performed in 85.0% of adenocarcinomas, 60.4% of NSCLC-not otherwise specified (NOS) and 17.4% of squamous cell carcinomas. Testing rates were highest for EGFR and ALK (adenocarcinoma: 82.7% and 80.7%, respectively). Incidence of molecular driver alterations (i.e. EGFR, KRAS, ALK, ROS1, BRAF, MET, ERBB2, FGFR1) was 61.1% for adenocarcinomas, 42.3% for NSCLC-NOS, and 24.7% for squamous cell carcinomas. Therapeutically relevant alterations were detected at a higher frequency by NGS- versus non-NGS-approaches (adenocarcinoma: 62.4% versus 56.5%, respectively (P = 0.004)) due to a lower failure rate, more comprehensive testing and higher sensitivity. Uptake of treatment with a registered targeted therapy in eligible patients varied per actionable target, i.e. EGFR: 85.8%, ALK: 74.7%, ROS1: 33.7%, BRAF: 51.5%. Treatment with agents in clinical studies/compassionate use was lower, i.e. MET: 22.8%, HER2: 18.9%, RET: 6.7%. ConclusionReal-world data show NGS-based approaches to be superior to non-NGS. Uptake of molecular testing and the corresponding targeted treatments was less than expected based on guidelines and even more so for trials, off-label use and compassionate use, indicating less than optimal access to rational treatment options.

Abstract PD14-07: Bromodomain and Extra-Terminal motif (BET) inhibitors are a rational therapeutic choice for treatment of invasive lobular carcinoma

Abstract Invasive lobular carcinoma (ILC) is the second most common type of breast cancer accounting for approximately 10-15% of all breast tumours. ILC is characterized by inactivation of E-Cadherin and cancer cells that invade the stroma in a "single-file" pattern. Women with ILC are more likely to have hormone receptor-positive disease. ILCs are three times more likely to metastasize to the peritoneum, gastrointestinal tract, and ovaries. ILC are currently treated in the same manner as all other ER+ breast cancers. Like invasive ductal carcinoma (IDC), anti-estrogen resistance has emerged as a significant problem in the management of ILC. Approximately half of the recurrences of ER+ breast tumors respond to anti-endocrine treatment, while the other half are resistant. Additionally, anti-estrogen-resistant breast tumor cells appear to have/acquire a more aggressive, invasive phenotype compared to their anti-estrogen-responsive counterparts. ILC is considered to be chemo-resistant and ILC patients receive no additional benefit from adjuvant chemotherapy. As such, there is a pressing need to develop tailored therapeutic options for endocrine-resistant ILC patients. The bromodomain and extra-terminal (BET) motif family are epigenetic readers that bind to acetylated histones, recruiting co-factors to regulate transcription. As part of the FP7 RATHER project aimed at identifying rational treatment options for ILC, we discovered that BRD3 (uniquely among the BET family members) is a marker of poor prognosis in ILC but not in ER+ breast cancers as a whole. We subsequently validated this in an independent cohort from the METABRIC study. These data suggest that Brd3 may play a significant role in tumour progression in ILC and may be a rational therapeutic target for lobular tumours. Using the two ILC cell lines SUM44PE (SUM44) and MDA MB 134 VI (MM134) previously shown to be anti-endocrine resistant we assessed the therapeutic potential of BET inhibition. We found that ILC cell lines that do not respond to anti-endocrine therapy are sensitive to a panel of BET inhibitors in both 2D and 3D assays. In particular the BET inhibitors JQ1 and Mivebresib had the highest potency, these BET inhibitors were selected for further research. Next, a multi-omics approach merging RNA-sequencing with mass spectrometry was utilised to dissect the transcriptional networks employed by BET inhibitors in this ILC setting. RNA-sequencing revealed dysregulated pathways in cell cycle division, DNA damage, apoptosis and MAPK signalling following treatment. Further, rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME) was carried out to find the binding partners of the BRD proteins. Integrated pathway analysis through Genome Enhancer was used to assess the master regulators (MTRs) which drive BET inhibitor function. There was 142 MTRs found across the two cell lines treated with both inhibitors. Of note the MTR, FGFR3, was shown to regulate the downstream targets of both BET inhibitors. Further analysis of BET inhibition combined with erdafitinib, an FGFR inhibitor, drives increased cell inhibition compared to either agent alone. Finally, the efficacy of JQ1 in targeting ILC was assessed in vivo. We utilised the ILC cell-derived xenograft (CDX) models established by mammary intraductal implantation. The efficacy of BET inhibition alone and in combination with anti-endocrine therapies, tamoxifen and fulvestrant were assessed in the MM134 cell line. We found that JQ1 works synergistically with tamoxifen to significantly decrease tumour burden and metastatic potential in this tamoxifen resistant ILC model. Taken together this data highlights the need for tailored therapeutics in ILC research and highlights the use of BET inhibition in the anti-endocrine resistant ILC setting. Citation Format: Elspeth Ward, Anna Blümel, Emer Conroy, Grainne Cremin, Binbin Gao, William Gallagher, Idalia Cruz, Leena Hilakivi-Clarke, George Sflomos, Cathrin Brisken, Darran O'Connor. Bromodomain and Extra-Terminal motif (BET) inhibitors are a rational therapeutic choice for treatment of invasive lobular carcinoma [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD14-07.

COVID-19 Pnömonisi ile İlişkili Akut Solunum Sıkıntısı Sendromunda tek doz (400 mg) ve çift doz (800 mg) Tocilizumab ile Tedavinin Değerlendirilmesi

Background: COVID-19 is a viral infectious caused by novel coronavirus called as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recent studies have shown that the level of IL-6 in the severe infection group was higher than that in the moderate group, suggesting that IL-6 can be used as a biomarker for severity assessment. However, the correlation of IL-6 levels in critically ill patients is still unknown. Tocilizumab is a monoclonal antibody against the IL-6 receptor and commonly used for cytokine storm or macrophage activation syndrome (MAS) in COVID-19 patients. Objective: In this study, we wanted to compare the clinical outcomes of different doses of tocilizumab (400 mg and 800 mg) as treatment. Methods:In this retrospective analysis we have included 120 patients with mild Acute Respiratory Distress Syndrome (ARDS) associated with COVID-19 pneumonia who received tocilizumab 400 mg once or twice daily. The two treatment groups were compared in terms of age, gender, comorbid diseases, arterial oxygen pressure (PaO2), oxygen saturation (SaO2) on room air, admission to the intensive care, length of stay in the intensive care unit, status of intubation, mortality, C reactive protein, white blood cell count, platelets, neutrophil, lymphocyte, ferritin, D-dimer, procalcitonin levels. Results: There were no statistically significant difference between the two dosing regimens in gender, arterial oxygen pressure (PaO2), oxygen saturation (SaO2) on room air, comorbidities, need for intubation, mortality, requirement for intensive care, total length of hospital stay, length of stay in intensive care, CRP, WBC, platelets, neutrophils, lymphocytes, ferritin, D-dimer and procalcitonin levels. Conclusion : Currently the short and long term adverse effects of tocilizumab have not been clearly reported in the literature. The clinical outcomes of once or twice daily tocilizumab did not differ significantly in terms of efficacy. Therefore a single dose of 400 mg once daily tocilizumab could be a rational treatment option.