The MDM2-p53 Axis Represents a Therapeutic Vulnerability Unique to Glioma Stem Cells.

The prevention of tumor recurrence by the successful targeting of glioma stem cells endowed with a tumor-initiating capacity is deemed the key to the long-term survival of glioblastoma patients. Glioma stem cells are characterized by their marked therapeutic resistance; however, recent evidence suggests that they have unique vulnerabilities that may be therapeutically targeted. We investigated MDM2 expression levels in glioma stem cells and their non-stem cell counterparts and the effects of the genetic and pharmacological inhibition of MDM2 on the viability of these cells as well as downstream molecular pathways. The results obtained showed that MDM2 expression was substantially higher in glioma stem cells than in their non-stem cell counterparts and also that the inhibition of MDM2, either genetically or pharmacologically, induced a more pronounced activation of the p53 pathway and apoptotic cell death in the former than in the latter. Specifically, the inhibition of MDM2 caused a p53-dependent increase in the expression of BAX and PUMA and a decrease in the expression of survivin, both of which significantly contributed to the apoptotic death of glioma stem cells. The present study identified the MDM2-p53 axis as a novel therapeutic vulnerability, or an Achilles' heel, which is unique to glioma stem cells. Our results, which suggest that non-stem, bulk tumor cells are less sensitive to MDM2 inhibitors, may help guide the selection of glioblastoma patients suitable for MDM2 inhibitor therapy.

Outcomes of thoracic endovascular aortic repair using fenestrated stent grafts in patients with thoracic aortic distal arch aneurysms.

OBJECTIVES: Thoracic endovascular aortic repair (TEVAR) for aortic arch aneurysms is challenging because of anatomical restrictions and the presence of cervical branches. Revascularization of the cervical branch is required when conventional commercial stent grafts are used. TEVAR using fenestrated stent grafts (FSG) often does not require additional procedures to revascularize cervical branches. This study aimed to evaluate the features and initial and midterm outcomes of TEVAR using fenestrated stent grafts. METHODS: From April 2007 to December 2016, 101 consecutive patients underwent TEVAR using fenestrated stent grafts for distal aortic arch aneurysms at a single centre. Technical success, complications, freedom from aneurysm-related death, secondary intervention and aneurysm progression were retrospectively investigated. RESULTS: All the patients underwent TEVAR using fenestrated stent grafts. The 30-day mortality rate was zero. Cerebral infarction, access route problems and spinal cord injury occurred in 4, 3 and 2 patients, respectively. Each type of endoleak was observed in 38 of the 101 patients during the course of the study; 20/38 patients had minor type 1 endoleaks at the time of discharge. The endoleak disappeared in 2 patients and showed no significant change in 8 patients; however, the aneurysm expanded over time in 10 patients. Additional treatment was performed in 8 of the 10 patients with type 1 endoleaks and dilatation of the aneurysm. The rate of freedom from aneurysm-related death during the observation period was 98%. CONCLUSIONS: TEVAR with FSG is a simple procedure, with few complications. Additional treatment has been observed to reduce aneurysm-related deaths, even in patients with endoleaks and enlarged aneurysms. Based on this study, the outcomes of endovascular repair of aortic arch aneurysms using a fenestrated stent graft seem acceptable.

Patient characteristics correlate with diagnostic performance of photodynamic diagnostic assisted transurethral resection of bladder tumors: A retrospective, single-center study.

BACKGROUND: Identification of patient subclasses that correlate with the diagnostic performance of photodynamic diagnostic (PDD)-assisted transurethral resection of bladder tumors (TURBT) may improve outcomes. METHODS: Data were extracted from patients that underwent PDD-assisted TURBT at the University of Tsukuba Hospital between 2018 and 2023. Sensitivity and specificity were evaluated based on PDD findings (excluding WL findings) and pathology results. Cluster analysis using uniform manifold approximation and projection and k-means methods was performed, focusing on patients with malignant lesions. RESULTS: A total of 267 patients and 2082 specimens were extracted. Sensitivity was lowest with regard to BCG treatment (53.7 %), followed by flat lesions (57.2 %), urine cytology class ≥ III (62.9 %), and recurrent tumors (64.5 %). In the cluster analysis of 231 patients with malignant lesions, two showed lower sensitivity: Cluster 3 (62.4 %), consisting of patients with recurrent tumors and post-BCG treatment, and Cluster 4 (55.7 %), consisting of patients with primary tumors and urine cytology class ≥ III. Clusters 1 and 2, consisting of patients without BCG treatment and patients with lower urine cytology classes, exhibited higher sensitivities (94.4 % and 87.7 %). Among all clusters, Cluster 4 had the highest proportion of specimens which were negative for both PDD and white light (WL) findings but actually had malignant lesions (20.8 %). CONCLUSIONS: PDD-assisted TURBT sensitivity was lower in subclasses after BCG treatment or with cytology class III or higher. Random biopsy for PDD/WL double-negative lesions may improve diagnostic accuracy in these subclasses.

Objective Evaluation of Gaze Location Patterns Using Eye Tracking During Cystoscopy and Artificial Intelligence-Assisted Lesion Detection.

Background: The diagnostic accuracy of cystoscopy varies according to the knowledge and experience of the performing physician. In this study, we evaluated the difference in cystoscopic gaze location patterns between medical students and urologists and assessed the differences in their eye movements when simultaneously observing conventional cystoscopic images and images with lesions detected by artificial intelligence (AI). Methodology: Eye-tracking measurements were performed, and observation patterns of participants (24 medical students and 10 urologists) viewing images from routine cystoscopic videos were analyzed. The cystoscopic video was captured preoperatively in a case of initial-onset noninvasive bladder cancer with three low-lying papillary tumors in the posterior, anterior, and neck areas (urothelial carcinoma, high grade, and pTa). The viewpoint coordinates and stop times during observation were obtained using a noncontact type of gaze tracking and gaze measurement system for screen-based gaze tracking. In addition, observation patterns of medical students and urologists during parallel observation of conventional cystoscopic videos and AI-assisted lesion detection videos were compared. Results: Compared with medical students, urologists exhibited a significantly higher degree of stationary gaze entropy when viewing cystoscopic images (p < 0.05), suggesting that urologists with expertise in identifying lesions efficiently observed a broader range of bladder mucosal surfaces on the screen, presumably with the conscious intent of identifying pathologic changes. When the participants observed conventional and AI-assisted lesion detection images side by side, contrary to urologists, medical students showed a higher proportion of attention directed toward AI-detected lesion images. Conclusion: Eye-tracking measurements during cystoscopic image assessment revealed that experienced specialists efficiently observed a wide range of video screens during cystoscopy. In addition, this study revealed how lesion images detected by AI are viewed. Observation patterns of observers' gaze may have implications for assessing and improving proficiency and serving educational purposes. To the best of our knowledge, this is the first study to utilize eye tracking in cystoscopy. University of Tsukuba Hospital, clinical research reference number R02-122.

Retroperitoneal sarcoma: a 10-year follow-up analysis using hospital-based cancer registry data in Japan.

OBJECTIVES: We sought clinical characteristics, survival outcomes, and prognostic factors for overall survival of retroperitoneal sarcoma in Japan. METHODS: A Japanese hospital-based cancer registry database with a pivotal 10-year follow-up was used to identify and enroll patients, registered from 106 institutions, diagnosed with retroperitoneal sarcoma in 2008-2009. Treating hospitals were divided by hospital care volume; high-volume hospitals and low-volume hospitals were defined as ≥ 4 and < 4 cases/year, respectively. RESULTS: A total of 91 men and 97 women were included, with a median age of 64 years. The most common histological type was liposarcoma in 101 patients, followed by leiomyosarcoma in 38 patients. The 5-year and 10-year overall survival rates were 44.1 and 28.3%. The majority of patients (n = 152, 80.9%) were treated at low-volume hospitals. High-volume hospital patients had higher 10-year overall survival rates than low-volume hospital patients (51.2% vs 23.2%, P = 0.026). Multivariate analysis revealed age over 60 years, treatment in low-volume hospitals and chemotherapy were independent predictors of unfavorable survival while treatment with surgery was an independent predictor of favorable survival. CONCLUSIONS: The possibility of surgical removal was suggested to be the most important prognostic factor for retroperitoneal sarcoma. Better survival was shown in patients treated at high-volume hospitals in our series.

Adult genitourinary sarcoma: analysis using hospital-based cancer registry data in Japan.

BACKGROUND: Genitourinary sarcomas are rare in adults and few large-scale studies on adult genitourinary sarcoma are reported. We aimed to elucidate the clinical characteristics, survival outcomes, and prognostic factors for overall survival of adult genitourinary sarcoma in Japan. METHODS: A hospital-based cancer registry data in Japan was used to identify and enroll patients diagnosed with genitourinary sarcoma in 2013. The datasets were registered from 121 institutions. RESULTS: A total of 116 men and 39 women were included, with a median age of 66 years. The most common primary site was the kidney in 47 patients, followed by the paratestis in 36 patients. The most common histological type was liposarcoma in 54 patients, followed by leiomyosarcoma in 25 patients. The 5-year overall survival rates were 57.6%. On univariate analysis, male gender, paratestis as primary organ, and histological subtype of liposarcoma were predictive of favorable survival while primary kidney, bladder, or prostate gland location were predictive of unfavorable survival. On multivariate analysis, primary paratestis was an independent predictor of favorable survival while primary kidney, bladder, or prostate gland were independent predictors of unfavorable survival. CONCLUSIONS: This is the first report showing the clinical characteristics and survival outcomes of adult genitourinary sarcoma in Japan using a real-world large cohort database.

The prognostic impact of treatment centralization in patients with testicular germ cell tumors: analysis of hospital-based cancer registry data in Japan.

BACKGROUND: To identify the prognostic impact of treatment centralization in patients with testicular germ cell tumors (TGCT). METHODS: We used a hospital-based cancer registry data in Japan to extract seminoma and non-seminoma cases that were diagnosed in 2013, histologically confirmed, and received the first course of treatment. To compare the 5-years overall survival (OS) rates of patients stratified by institutional care volume, we performed a Cox proportional hazards regression analysis using inverse probability of treatment weighting (IPTW) method to adjust patient backgrounds. RESULTS: A total of 1767 TGCT patients were identified. The 5-years OS rates for stage II and III TGCT patients treated at low-volume institutions (< 7 cases) were significantly worse than high-volume institutions (≥ 7 cases) (91.2% vs. 83.4%, p = 0.012). Histological stratification revealed that 5-year OS rates for stage II and III seminoma patients in the low-volume group were significantly worse than the high-volume group (93.5% vs. 84.5%, p = 0.041). Multivariate OS analysis using an IPTW-matched cohort showed that institutional care volume was an independent prognostic factor (hazard ratio 2.13 [95% confidence interval: 1.23-3.71], p = 0.0072). CONCLUSION: Our results indicate that stage II and III TGCT patients experience lower survival rates at low-volume institutions and would benefit from treatment centralization.

CEP-1347 Dually Targets MDM4 and PKC to Activate p53 and Inhibit the Growth of Uveal Melanoma Cells.

Uveal melanoma (UM) is among the most common primary intraocular neoplasms in adults, with limited therapeutic options for advanced/metastatic disease. Since UM is characterized by infrequent p53 mutation coupled with the overexpression of MDM4, a major negative regulator of p53, we aimed to investigate in this study the effects on UM cells of CEP-1347, a novel MDM4 inhibitor with a known safety profile in humans. We also examined the impact of CEP-1347 on the protein kinase C (PKC) pathway, known to play a pivotal role in UM cell growth. High-grade UM cell lines were used to analyze the effects of genetic and pharmacological inhibition of MDM4 and PKC, respectively, as well as those of CEP-1347 treatment, on p53 expression and cell viability. The results showed that, at its clinically relevant concentrations, CEP-1347 reduced not only MDM4 expression but also PKC activity, activated the p53 pathway, and effectively inhibited the growth of UM cells. Importantly, whereas inhibition of either MDM4 expression or PKC activity alone failed to efficiently activate p53 and inhibit cell growth, inhibition of both resulted in effective activation of p53 and inhibition of cell growth. These data suggest that there exists a hitherto unrecognized interaction between MDM4 and PKC to inactivate the p53-dependent growth control in UM cells. CEP-1347, which dually targets MDM4 and PKC, could therefore be a promising therapeutic candidate in the treatment of UM.

[Elderly Advanced Breast Cancer Effectively Treated with Locoregional Therapy-A Case Report].

We report a case of advanced breast cancer in an elderly patient effectively treated with locoregional therapy. The patient was an 81-year-old woman who presented with an increasing right breast lump. The tumor was 55 mm in diameter, accompanied by fixation to pectoral muscle. A core needle biopsy for right breast tumor led to a diagnosis of mucinous carcinoma, positive for estrogen receptor(ER)and progesterone receptor(PgR), negative for HER2/neu. The Ki-67 positive cell index was 10%. A bone scintigraphy revealed multiple bone metastases, so, we confirmed the diagnosis as T4cN2aM1, Stage Ⅳ. She initiated endocrine therapy by letrozole. By changing the endocrine therapy to toremifene followed by fulvestrant, the therapy achieved a partial response. However, the size of the primary tumor increased accompanied by bleeding, and surgical resection of the right breast was performed for local control. The locoregional surgery was effective, improving the patient's quality of life. She was administered lapatinib as anti-HER2 therapy in addition to the endocrine therapy. Two years and 6 months after surgery, there has been no worsening of bone metastasis or appearance of visceral metastasis.

[Recurrent Breast Cancer with Bone Metastasis Effectively Treated with Abemaciclib plus Endocrine Therapy-A Case Report].

We report a case of recurrent breast cancer with bone metastasis in a premenopausal woman. A 46-year-old woman underwent mastectomy for right breast cancer 6 years ago. Histopathological diagnosis was invasive ductal carcinoma, T2N3aM0, stage ⅢC. She received adjuvant chemotherapy and irradiation followed by tamoxifen. Four and a half years after surgery, serum tumor marker levels elevated, and bone metastasis in the sacral region was revealed by PET-CT scan. After suppressing ovarian function with LH-RH agonist, we switched the endocrine therapy from tamoxifen to letrozole with a CDK4/6 inhibitor. Five months after starting administration of abemaciclib, the bone metastasis disappeared on PET-CT. The elevated tumor markers normalized and have continued to decrease. Abemaciclib combined with endocrine therapy was significantly effective as first-line treatment for premenopausal women with metastatic breast cancer.