Tomokazu Sazuka

Dr. Tomokazu Sazuka


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2024 in International Journal of Urology
Verified
Journal Article
Open access
YKYuki Kita
Yuki Kita
HOHikari Otsuka
Hikari Otsuka
KIKatsuhiro Ito
Katsuhiro Ito
THTakuto Hara
Takuto Hara
SSSoichiro Shimura
Soichiro Shimura
TGthe Japan Urological Oncology Group
the Japan Urological Oncology Group
Objectives: Immune checkpoint inhibitors and enfortumab vedotin have opened new avenues for sequential treatment strategies for locally advanced/metastatic urothelial carcinoma (la/mUC). In the pre‐enfortumab vedotin era, many patients could not receive third‐line treatment owing to rapid disease progression and poor general status. This study aimed to analyze real‐world sequential treatment practices for la/mUC in Japan, with a focus on patients who do not receive third‐line treatment.Methods: We analyzed data for 1023 la/mUC patients diagnosed between January 2020 and December 2021 at 54 institutions from a Japanese nationwide cohort.Results: At the median follow‐up of 28.5 months, the median overall survival from first‐line initiation for 905 patients who received systemic anticancer treatment was 19.1 months. Among them, 81% and 32% received second‐ and third‐line treatment. Notably, 52% had their treatment terminated before the opportunity for third‐line treatment. Multivariate logistic regression analysis revealed that low performance status (≥1), elevated neutrophil‐to‐lymphocyte ratio (≥3), and low body mass index (<21 kg/m2) at the start of first‐line treatment were independent risk factors for not proceeding to third‐line treatment (p = 0.0024, 0.0069, and 0.0058, respectively). In this cohort, 33% had one of these factors, 36% had two, and 15% had all three.Conclusions: This study highlights the high frequency of factors associated with poor tolerance to anticancer treatment in la/mUC patients. The findings suggest the need to establish optimal sequential treatment strategies, maximizing efficacy within time and tolerance constraints, while concurrently providing strong supportive care, considering immunological and nutritional aspects.

21 February 2013 in Prostate Cancer
Verified
Journal Article
Open access
PDF file
TSTomokazu Sazuka
Tomokazu Sazuka
TITakashi Imamoto
Takashi Imamoto
TNTakeshi Namekawa
Takeshi Namekawa
TUTakanobu Utsumi
Takanobu Utsumi
MYMitsuru Yanagisawa
Mitsuru Yanagisawa
TITomohiko Ichikawa
Tomohiko Ichikawa
Background. The aim of this study was to determine concordance rates for prostatectomy specimens and transrectal needle biopsy samples in various areas of the prostate in order to assess diagnostic accuracy of the transrectal biopsy approach, especially for presurgical detection of cancer in the prostatic apex.Materials and Methods. From 2006 to 2011, 158 patients whose radical prostatectomy specimens had been evaluated were retrospectively enrolled in this study. Concordance rates for histopathology results of prostatectomy specimens and needle biopsy samples were evaluated in 8 prostatic sections (apex, middle, base, and transitional zones bilaterally) from 73 patients diagnosed at this institution, besides factors for detecting apex cancer in total 118 true positive and false negative apex cancers.Results. Prostate cancer was found most frequently (85%) in the apex of all patients. Of 584 histopathology sections, 153 (49%) from all areas were false negatives, as were 45% of apex biopsy samples. No readily available preoperative factors for detecting apex cancer were identified.Conclusions. In Japanese patients, the most frequent location of prostate cancer is in the apex. There is a high false negative rate for transrectal biopsy samples. To improve the detection rate, transperitoneal biopsy or more accurate imaging technology is needed.

12 February 2021 in Cancers
Verified
Journal Article
Open access
PDF file
KAKeisuke Ando
Keisuke Ando
Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
SSShinpei Saito
Shinpei Saito
MMMAIHULAN MAIMAITI
MAIHULAN MAIMAITI
YIYusuke Imamura
Yusuke Imamura
TITomohiko Ichikawa
Tomohiko Ichikawa
The Glasgow prognostic score, a marker of systemic inflammation, is associated with clinical outcomes in different cancers including prostate cancer. However, there is no evidence for the relationship between the high-sensitivity modified Glasgow prognostic score (Hs-mGPS) in prostate cancer and its prognosis. This study aimed to investigate the prognostic significance of Hs-mGPS in castration-resistant prostate cancer (CRPC) treated with docetaxel. We retrospectively analyzed clinical datasets from 131 CRPC patients who received docetaxel treatment at Chiba University Hospital and a related hospital. Clinical factors including Hs-mGPS before docetaxel treatment were evaluated according to overall survival. The numbers of patients with Hs-mGPS of 0, 1, and 2 were 88, 30, and 13, respectively. The median prostate-specific antigen (PSA) level was 28.9 ng/mL. The median testosterone level was 13.0 ng/dL. The percentages of bone and visceral metastases were 80.8% and 10.2%, respectively. For overall survival, Hs-mGPS ≥ 1 (hazard ratio of 2.41; p = 0.0048), testosterone ≥ 13.0 ng/dL (hazard ratio of 2.23; p = 0.0117), and PSA ≥ 28.9 ng/mL (hazard ratio of 2.36; p = 0.0097) were significant poor prognostic factors in the multivariate analysis. The results of the two-group analysis showed that a higher Hs-mGPS was associated with high PSA, alkaline phosphatase, and testosterone levels. The median testosterone levels for Hs-mGPS of 0, 1, and 2 were 9.0, 16.5, and 23.0, respectively. Based on the multivariate analysis, we created a combined score with three prognostic factors: Hs-mGPS, testosterone, and PSA. The low-risk group (score of 0–1) showed a significantly longer overall survival compared to the intermediate-risk (score of 2–3) and high-risk (score of 4) groups (p < 0.0001). Our results demonstrated that an elevated Hs-mGPS was an independent prognostic factor in CRPC patients treated with docetaxel therapy. Risk classification based on Hs-mGPS, testosterone, and PSA may be useful in predicting the prognosis of CRPC patients.

23 November 2023 in Scientific Reports
Verified
Journal Article
Open access
PDF file
TSTomokazu Sazuka
Tomokazu Sazuka
YMYuto Matsushita
Yuto Matsushita
HSHiroaki Sato
Hiroaki Sato
TOTakahiro Osawa
Takahiro Osawa
NHNobuyuki Hinata
Nobuyuki Hinata
TITomohiko Ichikawa
Tomohiko Ichikawa
Immuno-oncology (IO) combination therapy is utilized as a first-line systemic treatment for advanced renal cell carcinoma. However, evidence supporting the use of cabozantinib after IO combination therapy is lacking. We retrospectively analyzed patients who received second-line cabozantinib after IO combination therapy using the Japanese Urological Oncology Group (JUOG) database. In total, 254 patients were enrolled in the JUOG global study, and 118 patients who received second-line cabozantinib comprised the study cohort. The objective response rate, disease control rate, second-line cabozantinib progression-free survival (PFS), and overall survival from second-line for overall were 32%, 75%, 10.5 months, and not reached, respectively, for first-line IO-IO therapy were 37%, 77%, 11.1 months, and not reached, respectively, versus 24%, 71%, 8.3 months, and not reached, respectively, for first-line IO-tyrosine kinase inhibitor therapy. In univariate and multivariate analyses, discontinuation of first-line treatment because of progressive disease and liver metastasis were independent risk factors for PFS. All-grade adverse events occurred in 72% of patients, and grade 3 or higher adverse events occurred in 28% of patients. Second line-cabozantinib after first-line IO combination therapy for advanced renal cell carcinoma was expected to be effective after either IO-IO or IO-TKI treatment and feasible in real-world practice.

Verified
Journal Article
Open access
PDF file
XZXue Zhao
Xue Zhao
Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
JWJiaxing Wei
Jiaxing Wei
SPSangjon Pae
Sangjon Pae
SSShinpei Saito
Shinpei Saito
TITomohiko Ichikawa
Tomohiko Ichikawa
The L-type amino acid transporter (LAT) family contains four members, LAT1~4, which are important amino acid transporters. They mainly transport specific amino acids through cell membranes, provide nutrients to cells, and are involved in a variety of metabolic pathways. They regulate the mTOR signaling pathway which has been found to be strongly linked to cancer in recent years. However, in the field of prostate cancer (PCa), the LAT family is still in the nascent stage of research, and the importance of LATs in the diagnosis and treatment of prostate cancer is still unknown. Therefore, this article aims to report the role of LATs in prostate cancer and their clinical significance and application. LATs promote the progression of prostate cancer by increasing amino acid uptake, activating the mammalian target of rapamycin (mTOR) pathway and downstream signals, mediating castration-resistance, promoting tumor angiogenesis, and enhancing chemotherapy resistance. The importance of LATs as diagnostic and therapeutic targets for prostate cancer was emphasized and the latest research results were introduced. In addition, we introduced selective LAT1 inhibitors, including JPH203 and OKY034, which showed excellent inhibitory effects on the proliferation of various tumor cells. This is the future direction of amino acid transporter targeting therapy drugs.

19 January 2024 in International Journal of Urology
Verified
Journal Article
Closed access
YMYuto Matsushita
Yuto Matsushita
TKTakahiro Kojima
Takahiro Kojima
TOTakahiro Osawa
Takahiro Osawa
TSTomokazu Sazuka
Tomokazu Sazuka
SHShingo Hatakeyama
Shingo Hatakeyama
TGthe Japanese Urological Oncology Group
the Japanese Urological Oncology Group