Koji Mitsuzuka

Pathological and biochemical outcomes after radical prostatectomy in men with low-risk prostate cancer meeting the Prostate Cancer International: Active Surveillance criteria.

Active surveillance has been widely accepted as a treatment tool for low‐risk prostate cancer, and use of the Prostate Cancer Research International: Active Surveillance (PRIAS) criteria can select smaller and less aggressive tumours in low‐risk disease. The study shows the pathological outcomes of radical prostatectomy for patients with low‐risk disease who met the PRIAS criteria. It found that ∼20% had unfavourable pathological features and only 30% satisfied insignificant cancer criteria with pT2 stage, a Gleason score ≤6 and tumour volume <2.5 mL. It concludes that close follow‐up including repeat biopsy or MRI is necessary to minimize unexpected progression of disease.

Inhibition of motility and invasiveness of renal cell carcinoma induced by short interfering RNA transfection of β1,4GalNAc transferase

Human renal cell carcinoma (RCC) has been characterized by remarkable changes in ganglioside composition. TOS1 cells, typical of metastatic RCC, are characterized by predominance of GM2 as monosialoganglioside, and β1,4GalNAc disialyl‐Lc4 (RM2 antigen) as disialoganglioside [J. Biol. Chem. 276 (2001) 16695]. In order to observe the functional role of gangliosides in RCC malignancy, TOS1 cells were transfected with short interfering RNA (siRNA) based on open reading frame sequence of β1,4GalNAc transferase (β1,4GalNAc‐T), and its disordered sequence of siRNA (dsiRNA) as control. In siRNA transfectant, β1,4GalNAc‐T mRNA level and GM2 expression were greatly reduced, whereby GM3 expression appeared. In contrast, RM2 antigen level was unchanged, even though it has the same β1,4GalNAc epitope at the terminus. dsiRNA transfectant showed no change of β1,4GalNAc‐T mRNA and did not express GM3. Concomitant with reduction of GM2 and appearance of GM3, siRNA transfectant showed greatly reduced motility and invasiveness, although growth rate was unaltered. Both transfectants with siRNA and dsiRNA expressed the same level of tetraspanin CD9. Since CD9/GM3 complex is known to reduce integrin‐dependent motility and invasiveness [Biochemistry 40 (2001) 6414], it is plausible that motility and invasiveness of siRNA transfectant of TOS1 cells may be reduced by enhanced formation of such complex.

Long-term quality of life after radical prostatectomy: 8-Year longitudinal study in Japan

To assess long‐term health‐related quality of life in patients undergoing radical prostatectomy.

Impact of body mass index on clinicopathological outcome and biochemical recurrence after radical prostatectomy

Background:Accumulating evidence suggests that obesity is associated with tumor progression in prostate cancer (PCa) patients after radical prostatectomy (RP). We conducted a retrospective multicenter study to determine the effect of body mass index (BMI) on the clinicopathological characteristics and biochemical recurrence of PCa in Japanese men who underwent RP.Methods:The medical records of 1257 men with PCa treated by RP without neoadjuvant therapy at four medical institutes between 2001 and 2009 were retrospectively reviewed. Patients were categorized into four groups using the World Health Organization (WHO) BMI classification and BMI quartiles. Associations of the various BMI categories with clinicopathological characteristics and biochemical recurrences were statistically evaluated. Biochemical recurrence was defined as a PSA level of >0.2 ng ml–1.Results:Of the 1257 patients, 230 (18.3%) experienced biochemical recurrence during the median follow-up period of 49 months. The median BMI was 23.8 kg m–2, and 1.4% patients were underweight, 65.4% were of normal weight, 30.9% were overweight and 2.4% were obese (WHO classification). Preoperative PSA levels and PSA density (PSAD) tended to decrease as BMI increased. Pathological characteristics did not differ significantly among BMI categories. As per the WHO classification and quartile categories, biochemical recurrence rate was comparable among the BMI groups. After adjusting for other pre- and postoperative covariables, multivariate Cox proportional hazards analysis revealed that a high BMI did not have an independent impact on biochemical recurrence-free survival.Conclusions:Underweight Japanese PCa patients treated by RP had higher preoperative PSA levels and PSAD. High BMI was not associated with adverse pathological findings or increased biochemical recurrence rate in Japanese PCa patients treated with RP. Racial differences may exist in the relationship between obesity and outcomes of RP in PCa patients.

Current use of active surveillance for localized prostate cancer: A nationwide survey in Japan

To understand the current practice pattern of active surveillance using a nationwide survey among Japanese urologists.

Influence of 1 year of androgen deprivation therapy on lipid and glucose metabolism and fat accumulation in Japanese patients with prostate cancer

Background:We prospectively examined influence of androgen deprivation therapy (ADT) on lipid and glucose metabolisms in Japanese patients with prostate cancer.Methods:Patients with prostate cancer who were hormone-naive and scheduled to receive long-term ADT were recruited between 2011 and 2013. Body weight, abdominal circumference and blood testing associated with lipid and glucose metabolism were recorded every 3 months during 1 year of ADT. Computed tomography (CT) was performed to measure areas of subcutaneous and visceral fat before and after 1 year of ADT. ADT was limited to a luteinizing hormone-releasing hormone (LHRH) agonist with or without bicalutamide.Results:Of 218 patients registered, data were available from 177 patients who completed 1 year of ADT. Of these, CT was performed before and after 1 year of ADT in 88 patients. Median age was 75 years (range, 49–85 years). Median PSA before ADT was 16.7 ng ml−1 (range, 0.3–3316). Clinical stage was B (54.2%), C (23.2%) and D (20.9%). Mean increases in body weight and abdominal circumference after 1 year of ADT were 2.9 and 3.0%, respectively. Mean increases in total, low-density lipoprotein and high-density lipoprotein cholesterol and triglycerides were 10.6, 14.3, 7.8 and 16.2%, respectively. Mean increases in fasting blood sugar and hemoglobin A1c (HbA1c) were 3.9 and 2.7%, respectively. Lipid alterations were noted in patients without comorbidities, whereas changes in HbA1c were noted in patients with diabetes mellitus at baseline. These lipid and glucose alterations were prominent in the early ADT period. Both visceral and subcutaneous fat, as measured by CT, increased by >20%. The increase in subcutaneous fat was significantly greater than that in visceral fat (P=0.028).Conclusions:One year of ADT significantly changed lipid and glucose metabolism in Japanese patients with prostate cancer. Patient characteristics or comorbidities at baseline may be associated with ADT-induced metabolic changes.

Lymphovascular invasion is significantly associated with biochemical relapse after radical prostatectomy even in patients with pT2N0 negative resection margin

BACKGROUND:The significance of lymphovascular invasion (LVI) remains controversial, and the association of LVI with biochemical relapse was investigated in men treated with radical prostatectomy according to pathological results.METHODS:Data from 1268 patients undergoing radical prostatectomy between 2000 and 2009 were retrospectively reviewed. Clinicopathological variables were compared between LVI-negative and LVI-positive patients. Multivariate analyses by Cox proportional hazard model and Kaplan-Meier method were performed to identify risk factors for biochemical relapse in all patients, patients with pT2N0 and pT2N0 negative resection margin (RM).RESULTS:LVI information was available in 1160 cases, and LVI was seen in 121 cases (10.4%). Clinicopathological variables were significantly worse in LVI-positive patients than in LVI-negative patients. On multivariate analyses, PSA⩾10 ng ml−1, pathological Gleason score ⩾8, pathological T stage ⩾3, lymph node metastasis, positive RM and LVI were independent predictors for biochemical relapse in all patients. In patients with pT2N0, PSA⩾10 ng ml−1, pathological Gleason score ⩾8, positive RM and LVI were independent predictors for biochemical relapse. In patients with pT2N0 negative RM, LVI and pathological Gleason score ⩾8 were independent predictors for biochemical relapse (LVI; hazard ratio 3.809, 95% confidence interval 1.900–7.635, P-value<0.001, Gleason score ⩾8; hazard ratio 2.189, 95% confidence interval 1.199–3.999, P-value=0.011). With a median follow-up of 50 months, 5-year biochemical relapse-free survival in patients with pT2N0 negative RM was 95.7% in those with negative LVI in comparison to 85.3% in those with positive LVI (P<0.001, log rank).CONCLUSIONS:LVI was consistently a significant predictor for biochemical relapse after radical prostatectomy in not only all patients but also in patients with pT2N0 and pT2N0 negative RM. These results strongly support the significance of LVI as a predictor for biochemical relapse.

Spontaneous rupture of a renal angiomyolipoma at 25 weeks of pregnancy treated with transarterial embolization: A case report and review of the literature.

Treatment for ruptured renal angiomyolipoma in pregnancy requires immediate and appropriate decision‐making based on the condition of the mother and fetus, and gestational age. A 37‐year‐old woman at 25 weeks of pregnancy presented with severe right flank pain. Computed tomography showed a ruptured right renal angiomyolipoma (8 cm in diameter). The maternal and fetal conditions were stable. Transcatheter arterial embolization was carried out electively 4 days after the rupture. Minimization of radiation exposure to the fetus was achieved by X‐ray shielding for the fetus, low‐dose‐rate fluoroscopy, minimal angiography imaging and a color Doppler ultrasonography‐guided procedure. Although threatened premature labor occurred because of post‐embolization syndrome, the pregnancy was continued until cesarean section at 37 weeks of pregnancy.

Renal Hypothermia Using Ice-cold Saline for Retroperitoneal Laparoscopic Partial Nephrectomy: Evaluation of Split Renal Function With Technetium-99m-Dimercaptosuccinic Acid Renal Scintigraphy

OBJECTIVES To evaluate the changes in split renal function after retroperitoneal laparoscopic partial nephrectomy with renal hypothermia using ice-cold saline. METHODS From June 2002 to October 2009, 32 patients (median age 56 years) underwent retroperitoneal laparoscopic partial nephrectomy with hypothermia using ice-cold saline for the treatment of small renal tumors. The total renal function was monitored using the estimated glomerular filtration rate. Split renal function was evaluated using technetium-99m dimercaptosuccinic acid renal scintigraphy preoperatively and 3 months postoperatively. RESULTS The median renal ischemic time, including the initial 10 minutes for cooling, was 52 minutes (range 28-101). Of the patients whose renal temperature was monitored, the lowest renal temperature during cooling was 15-25°C. The median decrease in the estimated glomerular filtration rate was 7.2 mL/min/1.73 m(2) (range -16.3 to 33.7). The median decrease in the contribution of the affected kidney to global renal function was 5.3% (range 0.4%-21.1%). On multivariate analysis, a shorter ischemia duration was an independent predictor of a lesser decrease in the contribution of the affected kidney (P = .0032). CONCLUSIONS The methods we have described are simple and effective to facilitate suboptimal hypothermia. The decrease in the renal contribution of the affected kidney appeared to be minimal, although the ischemic time was relatively longer in our series.

Is pelvic lymph node dissection required at radical prostatectomy for low‐risk prostate cancer?

To determine the necessity of pelvic lymph node dissection for low‐risk prostate cancer, we analyzed the incidence of lymph node invasion and the therapeutic value of pelvic lymph node dissection in low‐risk prostate cancer patients.