Published papers

© 2019 Objective: Our specific aim was to introduce the TachoSil binding suturing technique for renal cell carcinoma (RCC) patients when closing the parenchymal defect after tumor excision during laparoscopic partial nephrectomy (LPN), which is a novel technique for reducing the risk of developing subsequent pseudoaneurysm (PA). Methods: We identified 113 pT1aN0M0 RCC patients who underwent LPN at our institution. Eighty-one (72%) patients underwent the suturing procedure without binding TachoSil, whereas 32 (28%) patients underwent renorraphy with the renal defect closed together with TachoSil. The vascular complications were evaluated by computed tomography or magnetic resonance imaging with enhanced contrast material at the first visit after LPN. We conducted Fischer's exact test to determine risk factors for transcatheter arterial embolization (TAE). Results: The median age was 55 (36–86) years old and the median follow-up time was 65 (12–147) months. In the overall population, there were 11 (11%) patients who underwent TAE because they developed PA. All 11 patients exhibited the imaging findings of PA, and were all from the conventional suturing group. In contrast, no patients for whom the TachoSil binding method was used had any significant findings on imaging (14% vs. 0%). Based on the analysis to determine risk factors for TAE due to PA development, the TachoSil binding suturing technique was one of the significant indicators for reducing the risk of developing PA. Conclusions: Our study demonstrated that the TachoSil binding suturing technique might reduce the development of PA after LPN. Prospective randomized study and comparison to the standard 2 or 3–layer renorrhaphy is needed to prove its actual value.

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: To examine the prognosis after BCR with and without salvage therapy, including radiation and/or androgen deprivation. Methods: The study population consisted of 431 patients, all of whom underwent radical prostatectomy and developed BCR (PSA > 0.2 ng/mL). According to the two risk factors [Gleason score ≥ 8 and PSA-doubling time (DT) < 6 months], we divided the patients into two groups. The high/intermediate-risk group consisted of patients with both or one risk factor. On the other hand, patients with neither factor were in the low-risk group. We set the starting point at the timing of BCR, and the endpoints were development to castration-resistant prostate cancer (CRPC) and cancer-specific death. Results: During the mean follow-up period of 8.3 years after BCR, CRPC was observed in 49 patients (11.4%), and 21 patients (4.9%) died due to prostate cancer. We first divided the 191 high/intermediate-risk patients according to the PSA level (PSA < 1.0 ng/mL, PSA 1.0–4.0, and PSA > 4.0 or no therapy) at the initiation of salvage therapy, including radiation and/or androgen deprivation. We found that delayed (PSA > 4.0 ng/mL) or no salvage therapy was significantly associated with CRPC and cancer-specific death. In the 240 low-risk patients, Kaplan–Meier curves demonstrated no significant difference in CRPC-free survival or cancer-specific survival within 10 years from the timing of BCR. Conclusions: Observation after BCR without salvage therapy or delayed administration may be an option for low-risk patients with a Gleason score ≤ 7 and PSA-DT ≥ 6 months when their life expectancy is within 10 years.

© 2020 The Author(s). Background: Ductal carcinoma of the prostate is a histological subtype with a higher mortality than acinar adenocarcinoma. The number of cases is small and there are no treatment guidelines. We believe that this is the first report of ductal carcinoma of the prostate with an adenomatosis polyposis coli (APC) gene mutation in Japan. Case presentation: An 85-year-old man presented with gross hematuria, and a papillary tumor in the prostatic urethra that was diagnosed as ductal carcinoma of the prostate following transurethral resection. Genetic analysis found an APC mutation with loss of heterozygosity. Immunostaining revealed focal nuclear translocation of β-catenin. APC mutations associated with loss of β-catenin degradation in the Wnt signaling pathway and result in over accumulation of β-catenin are thought to increase mortality. In this patient, β-catenin migrated into tumor cell nuclei. Conclusion: To the best of our knowledge, this is the first report of ductal carcinoma of the prostate with an APC mutation in Japan. The development of a therapeutic Wnt inhibitor is discussed.

© 2020 John Wiley & Sons Ltd Context: The oversecretion of plasma aldosterone by unilateral aldosterone-producing adenoma (APA) can be cured by adrenalectomy. However, the time needed for the endocrine environment to normalize remains unclear. Objective: To clarify adequate timing for a biochemical evaluation in unilateral APA patients after adrenalectomy. Design and patients: A total of 166 unilateral APA patients were retrospectively reviewed. We evaluated the plasma aldosterone concentration (PAC) (pg/mL), active renin concentration (ARC) (pg/mL), aldosterone-renin ratio (ARR; PAC/ARC), serum potassium concentration and estimated glomerular filtration rate (eGFR) at 1, 3 and 6 postoperation months (POM). Results: PAC was significantly lower at 1POM than at presurgery (presurgery; 407.2, 1 POM; 90.0 pg/mL, P <.001). ARC did not increase from baseline at 1POM, but significantly increased at 3POM (presurgery; 4.43, 1POM; 4.87, 3POM; 11.3 pg/mL, P <.001). ARR significantly decreased at 1POM (presurgery; 146.9, 1 POM; 26.3, P <.001) although ARC did not increase at 1POM. Among the 34 patients who had hypokalaemia presurgery, it was resolved in 28 (82%) at 1POM and in all (100%) at 3POM. The biochemical outcomes at 1POM were 131 (79%) complete, 20 (12%) partial and 15 (9%) absent successes, while at 3POM, 147 (89%) were complete, 9 (5%) partial and 10 (6%) absent. Twenty-three (14%) patients were reclassified into different biochemical outcomes between 1 and 3POM, whereas only 5 (3%) changed between 3 and 6POM. Conclusion: The appropriate timing for a biochemical evaluation of unilateral APA patients treated with laparoscopic adrenalectomy appears to be 3 months or more after surgery.

© 2020, Springer Nature B.V. Purpose: Intravesical bacillus Calmette–Guérin (BCG) is the standard of care for bladder carcinoma in situ (CIS). The response to BCG therapy against CIS is generally assessed by random bladder biopsy (RBB). In this study, we examined the necessity of routine RBB after BCG therapy. Methods: We retrospectively identified 102 patients who were initially diagnosed with CIS with or without papillary tumor and received subsequent 6–8-week BCG therapy. Thereafter, all patients underwent voiding cytology analysis, cystoscopy, and RBB to evaluate the effects of BCG therapy. We evaluated the association between clinical parameters (voiding cytology and cystoscopy findings) and the final pathological results by RBB specimens. Results: According to the pathological results of RBB, 30 (29%) patients had BCG-unresponsive disease (remaining urothelial carcinoma was confirmed pathologically) and 20 were diagnosed with CIS. Positive/suspicious voiding cytology and positive cystoscopy findings were well observed in patients who had BCG-unresponsive disease compared with their counterparts (p = 0.116, and p < 0.001, respectively). The sensitivity (Sen.), specificity (Spe.), positive predictive value (PPV), and negative predictive value (NPV) of voiding cytology were 50%, 68%, 39%, and 77%, respectively. The values for cystoscopy findings were as follows: Sen.: 87%, Spe.: 57%, PPV: 46%, and NPV: 91%. The values for their combination (having either of them) were as follows: Sen.: 100%, Spe.: 44%, PPV: 43%, and NPV: 100%. Conclusion: RBB after BCG therapy for patients with negative voiding cytology and negative cystoscopy may be omitted because their risk of BCG-unresponsive disease is significantly low (NPV: 100%).

© 2020, Society of Surgical Oncology. Purpose: To evaluate the oncological feasibility of pure laparoscopic radical nephroureterectomy (p-LRNU) for upper tract urothelial carcinoma (UTUC) compared with conventional LRNU (c-LRNU) using a propensity-adjusted multi-institutional collaboration dataset. Methods: Among the 503 UTUC patients who underwent RNU, we identified 219 who underwent c-LRNU (laparoscopic nephrectomy with open bladder cuff resection) and 72 who underwent p-LRNU (dissecting the kidney, ureter, and bladder cuff under complete laparoscopy). We adopted a propensity score (PS) matching method to achieve homogeneity with respect to patient backgrounds. PS matching-adjusted Cox-regression analysis was performed to evaluate the risk factors that influenced oncological outcomes. Results: Sixty-eight p-LRNU and 68 c-LRNU patients were matched. Overall, 51 (37.0%) developed intravesical recurrence (IVR), 21 (15.4%) had disease recurrence, and 20 (14.7%) died. Patients who underwent p-LRNU had a significantly shorter operation time and less blood loss than those who underwent c-LRNU. Although no significant differences in 3-year recurrence-free survival were found between the two methods, atypical recurrence sites were observed in the p-LRNU group, including the brain, sigmoid colon, vagina, and peritoneum. Regarding IVR, the 3-year IVR-free survival rate was 41.8% in the p-LRNU group, which was significantly lower than that in the c-LRNU group (66.6%, p = 0.004). Multivariate analysis demonstrated that a history of bladder cancer, ureteral cancer, and p-LRNU were independent risk factors for subsequent IVR. Conclusion: Although p-LRNU is less invasive, the current technique may increase the incidence of atypical disease recurrence and subsequent IVR due to extravesical and intravesical tumor dissemination.

© 2020 Elsevier Inc. Introduction: The aim of this study was to validate contemporary grading systems, in particular, the Gleason grade group (GGG) 5. Patients and Methods: We retrospectively reviewed the clinicopathologic data of 176 patients who underwent radical prostatectomy and whose pathologic results were GGG 4 or 5. The endpoints were biochemical recurrence (BCR) and castration-resistant prostate cancer (CRPC). Results: The GGG 4 group was composed of 69 patients. The GGG 5 group consisted of 78 patients with GS 4+5 and 29 patients with GS 5+4 or higher. The 5-year BCR-free survival rates for men with GGG 4, GS 4+5, and GS 5+4 or higher were 59%, 54%, and 20%, respectively, and the 5-year CRPC-free survival rates were 98%, 100%, and 88%, respectively. Both the BCR- and CRPC-free survival rates were significantly higher in GS 4+5 than in GS 5+4 or higher (P < .001 and P = .002, respectively), but there were no significant differences between GGG 4 and GS 4+5 (P = .702 and P = .803, respectively). The multivariate analysis demonstrated that GS 5+4 or higher (hazard ratio, 3.4; P = .002) and lymphovascular invasion (hazard ratio, 3.4; P < .001) greatly affected BCR. Conclusion: Our follow-up study revealed that men with GS 4+5 and those with GGG 4 had a similar prognosis. However, there was a significant discrepancy in prognosis between GS 4+5 and GS 5+4 or higher. This suggested that GGG 4 and 5 in the contemporary prostate cancer grading system should be reviewed. Furthermore, lymphovascular invasion may be useful to subgroup these pathologically high-risk patients.

© 2019 The Japanese Urological Association Objective: To examine a set of proposed eligibility factors for hemi-ablative focal therapy in prostate cancer and to determine the likelihood of residual extensive disease. Methods: We retrospectively analyzed data from 98 patients with unilateral prostate cancer on biopsy with detailed tumor maps from whole-mount slides and preoperative magnetic resonance imaging data. These patients met the focal therapy consensus meeting inclusion criteria (prostate-specific antigen <15 ng/mL, clinical stage T1c-T2a and Gleason score 3 + 3 or 3 + 4 on needle biopsy), and underwent radical prostatectomy between 2000 and 2014. Extensive disease was defined as having Gleason pattern 4/5 in bilateral lobes, any extraprostatic extension, seminal vesicle invasion or lymph node invasion. Both lobes of the prostate were scored on magnetic resonance imaging. Preoperative characteristics including biopsy and magnetic resonance imaging data were used to predict extensive disease. Results: Among our cohort of 98 patients, 40% (95% CI 30–50%) had extensive disease. A total of 33% (95% CI 24–43%) had Gleason pattern 4/5 in both lobes with a median Gleason pattern 4/5 tumor volume in the biopsy negative lobe of 0.06 cm3, 17 patients had pathological tumor stage ≥3 and one patient had lymph node invasion. Conclusions: An important number of patients meeting the focal therapy consensus meeting inclusion criteria can present extensive disease. Further studies using targeted biopsies might provide more accurate information about the selection of focal therapy candidates.

© 2020, Japan Society of Clinical Oncology. Background: Biochemical recurrence (BCR) after radical prostatectomy (RP) is most commonly diagnosed by detecting an increase in asymptomatic prostate-specific antigen (PSA). We previously reported the “optimal PSA follow-up schedule after RP”. The aim of this study was to confirm the usefulness and safety of that follow-up schedule in another cohort. Methods: We retrospectively reviewed the clinicopathological data of 798 consecutive patients who underwent radical prostatectomy between 2009 and 2017. We examined all PSA values measured during follow-up. Furthermore, we estimated the PSA value when we observed the “optimal PSA follow-up schedule” at each timing in the virtual follow-up. BCR was defined as an elevation of PSA to greater than 0.2 ng/ml, and the ideal PSA range for detection of BCR was regarded to be 0.2–0.4 ng/ml. Results: During the mean follow-up period of 5.8 years, BCR occurred in 115 (14.9%) patients and the frequency of virtual follow-up was significantly lower than the actual frequency. However, overlooking of BCR (detecting BCR when PSA exceeded 0.4 ng/ml) was observed in 17 patients, which is higher than the actual frequency of overlooking (12 patients). Therefore, we modified the follow-up schedule, which could achieve the lower follow-up frequency and a limited number of overlooking of BCR (7 patients). Conclusion: This external validation study revealed that the "modified optimal PSA follow-up schedule after RP" can reduce the frequency of PSA measurement with a limited risk of overlooking BCR.

© 2020, Japan Society of Clinical Oncology. Background: Liposarcoma is one of the most common subtypes of soft tissue sarcoma. Although the standard treatment for localized liposarcoma is surgical resection with negative margins, a treatment specific to paratesticular liposarcoma has yet to be quantitatively evaluated. Methods: A systematic search of Medline, Web of Science, Embase, and Google was performed to find articles describing localized paratesticular liposarcoma published between 1979 and 2018 in English. The final cohort included 265 patients in 183 articles. The starting point was the time of surgical treatment, and the endpoint was the time of recurrence, including local recurrence, or distant metastasis. Results: The median patient age was 62 years and the median tumor size was 9.5 cm. In total, 178 patients underwent high inguinal orchiectomy and 40 underwent simple tumorectomy. Based on the Kaplan–Meier curves, recurrence-free survival rates were significantly higher for those who underwent high inguinal orchiectomy than for those who underwent tumorectomy. Moreover, those with microscopic positive margins had a higher risk of recurrence than those with negative margins, but adjuvant radiation therapy after resection had no statistically significant effect on recurrence-free survival, even in subgroup analysis of patients with positive margins. Regarding the pathological subtypes, dedifferentiated, pleomorphic, and round-cell liposarcoma had a higher risk of recurrence than well-differentiated or myxoid liposarcoma. In the multivariate analysis, high inguinal orchiectomy greatly affected recurrence-free survival. The tumor size and histological subtype were independent risk factors for recurrence. Conclusion: Complete resection with high inguinal orchiectomy is the optimal treatment for paratesticular liposarcoma.

Introduction and Objective  In this study, we clarified patients suitable for single-port laparoscopic adrenalectomy by focusing on the optimal cut-off values of the body mass index (BMI).Methods  A retrospective study was conducted on 126 consecutive patients who underwent single-port adrenalectomy. We re-evaluated all medical records and surgical videos. The pneumoperitoneum time (PT) was employed as an objective index for the assessment of surgical difficulty.Results  The total mean PT was 84 minutes. In 27 patients with a BMI less than 20 kg/m2, the mean PT was 71 minutes, whereas the mean PT was 104 minutes in 9 patients with a BMI exceeding 28 kg/m2.Conclusions  Our results suggested that patients with a BMI less than 20 kg/m2 are suitable for novice surgeons. Conversely, even experienced surgeons should carefully consider performing single-port surgery on patients whose BMI exceeds 28 kg/m2.

腹腔鏡下副腎摘除術は，副腎腫瘍に対するゴールド・スタンダードな術式として既に定着している。近年，腹腔鏡手術のさらなる進化を求め，単孔式腹腔鏡手術（Laparoendoscopic single-site surgery：LESS surgery）への関心が高まっている。摘出臓器の大きさとしては，臍に留置したsingle portから傷の延長なく摘出可能な副腎は，腹壁へのダメージをより少なくできる単孔式腹腔鏡手術の非常に良い適応であると考えられる。しかしその手術難易度が，副腎に対する単孔式腹腔鏡手術普及の足かせとなっている。本稿では手術難易度を下げる術前および術中の工夫として，①適切な症例の選択，②適切な手術器具の選択，および③単孔式手術習得に必要なテクニックについてそれぞれ述べていきたい。

前立腺がんにおいて腫瘍発生領域が根治的前立腺全摘除術後再発に及ぼす影響を検討した。Pz発生腫瘍はTz発生腫瘍と比較してpT3症例169例において有意に生物学的再発リスクが高かった(HR:3.0、95%CI:1.1〜7.9、p=0.045)。腫瘍発生領域はpT3前立腺がんにおける術後再発予測に有用な可能性が示唆された。(著者抄録)

BACKGROUND: Almost half of patients with metastatic renal-cell carcinoma (mRCC) are classified as intermediate risk by the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model. The aim of this study was to evaluate whether baseline C-reactive protein (CRP) levels predict overall survival (OS) in intermediate-risk group mRCC patients. PATIENTS AND METHODS: Data from 107 intermediate-risk group mRCC patients receiving first-line targeted therapy were retrospectively reviewed. We evaluated the correlation between baseline CRP levels as well as other indices and OS. RESULTS: Of the 107 patients with intermediate-risk disease, 46 patients (43%) were classified as having elevated CRP levels. The elevation of pretreatment serum CRP levels was the independent prognostic factor of OS in patients with intermediate risk (hazard ratio, 4.609; P = .001). The 1- and 3-year survival rates of patients with intermediate-nonelevated CRP were 90.0% and 64.7% compared to the favorable-risk group, at 92.1% and 68.5%, respectively. In contrast, the 1- and 3-year survival rates of patients with intermediate-elevated CRP were 80.5% and 37.4% compared to the poor-risk group, at 65.2% and 24.2%, respectively. CONCLUSION: Baseline CRP levels could divide mRCC patients in the intermediate-risk group into 2 prognostic subgroups.

INTRODUCTION: To evaluate nephrostomy catheter displacement, we assessed the cumulative nephrostomy catheter displacement rate in patients with percutaneous nephrostomy and compared the nephrostomy displacement rates between pigtail and balloon catheters. MATERIALS AND METHODS: Between 2003 and 2011, 87 patients who underwent percutaneous nephrostomy catheter placement and more than one subsequent catheter replacement were retrospectively identified. We evaluated their inadvertent nephrostomy catheter displacement. RESULTS: 20 patients (23.0%) experienced incidental nephrostomy catheter displacement during the follow-up period. Kaplan-Meier analysis revealed that the 1-year nephrostomy catheter displacement-free survival rate was 62 +/- 9%. No significant independent risk factors for predicting nephrostomy catheter displacement were identified, including the type of catheter. The median time from initial placement to displacement of pigtail catheters was shorter than that of balloon catheters. CONCLUSION: There were no significant differences in the nephrostomy catheter displacement-free survival rates between the two types of catheters. Regardless of the type of catheter, our results indicated that careful handling and guiding during catheter placement are important for all patients because of the high risk of inadvertent events..

PURPOSE: To retrospectively measure metabolic ratios and apparent diffusion coefficient (ADC) values from 3-Tesla MR spectroscopic imaging (MRSI) and diffusion-weighted imaging (DWI) in benign and malignant peripheral zone (PZ) prostate tissue, assess the parameters' associations with malignancy, and develop and test rules for classifying benign and malignant PZ tissue using whole-mount step-section pathology as the reference standard. METHODS: This HIPAA-compliant, IRB-approved study included 67 men (median age, 61years; range, 41-74years) with biopsy-proven prostate cancer who underwent preoperative 3T endorectal multiparametric MRI and had >/=1 PZ lesion >0.1cm(3) at whole-mount histopathology. In benign and malignant PZ regions identified from pathology, voxel-based choline/citrate, polyamines/choline, polyamines/creatine, and (choline+polyamines+creatine)/citrate ratios were averaged, as were ADC values. Patients were randomly split into training and test sets; rules for separating benign from malignant regions were generated with classification and regression tree (CART) analysis and assessed on the test set for sensitivity and specificity. Odds ratios (OR) were evaluated using generalized estimating equations. RESULTS: CART analysis of all parameters identified only ADC and (choline+polyamines+creatine)/citrate as significant predictors of cancer. Sensitivity and specificity, respectively, were 0.81 and 0.82 with MRSI-derived, 0.98 and 0.51 with DWI-derived, and 0.79 and 0.90 with MRSI+DWI-derived classification rules. Areas under the curves (AUC) in the test set were 0.93 (0.87-0.97) with ADC, 0.82 (0.72-0.91) with MRSI, and 0.96 (0.92-0.99) with MRSI+ADC. CONCLUSION: We developed statistically-based rules for identifying PZ cancer using 3-Tesla MRSI, DWI, and MRSI+DWI and demonstrated the potential value of MRSI+DWI.

PURPOSE: Monitoring the serum level of prostate specific antigen (PSA) is indispensable for surveillance after radical therapy, and the aim of this study was to establish the optimal follow-up schedule. MATERIALS AND METHODS: We retrospectively reviewed the clinicopathological data of 1,010 consecutive patients who underwent radical prostatectomy. After excluding patients who received neoadjuvant or adjuvant therapy and those without a nadir PSA level<0.2ng/ml, the remaining 779 patients were enrolled. Biochemical recurrence (BCR) was defined as elevation of PSA to >0.2ng/ml. We investigated the PSA doubling time (PSA-DT) following BCR at various times after surgery. RESULTS: During a mean follow-up of 8.8 years, BCR occurred in 180/779 patients. The annual BCR rate was 6% in the first year after surgery, 6% between 1 and 2 years, 3% between 2 and 3 years, 3% between 3 and 5 years, and 2% at >5 years postoperatively. During these periods, the minimum PSA-DT after BCR was 1.6, 2.4, 3.1, 6.1, and 6.4 months, respectively. These minimum PSA-DTs were used to determine the optimal follow-up interval during each period after surgery. If the baseline level is 0.1ng/ml, PSA should be measured at approximately 3-month intervals for the first year, at 4-month intervals between 1 and 2 years, at 6-month intervals between 2 and 3 years, and annually thereafter to definitely detect BCR before the serum PSA level exceeds 0.4ng/ml. CONCLUSION: The PSA-DT following BCR varies according to the time after surgery. Our data on minimum PSA-DT values after BCR are useful for setting the optimal follow-up schedule.

PURPOSE: We tested the latest update in the prostate cancer staging system by assessing the prognostic association of pT2 subclassification with the probability of survival related outcomes in patients who underwent radical prostatectomy. MATERIALS AND METHODS: We retrospectively analyzed the records of a total of 15,305 patients who underwent radical prostatectomy at 2 referral centers between 1985 and 2016, and had pT2 disease at the final pathological evaluation. Descriptive statistics were used to compare baseline data stratified by pT2 substages (pT2a/b vs pT2c). Cox regression models were adjusted for institution analyzed differences in the rate of biochemical recurrence, metastasis, cancer specific death and overall mortality. Multivariable Cox regression models were used to evaluate the predictive value of pT2 subclassification for survival, including the linear predictor from the Stephenson nomogram. RESULTS: Prostate specific antigen levels and Gleason score differed significantly between the pT2 substages (each p <0.0001). At a median followup of 6.0 years (IQR 3.3-10.1) 2,083 patients had biochemical recurrence, 161 had metastases, 43 had died of prostate cancer and 1,032 had died of another cause. On univariate analysis the pT2 subclassification was significantly associated with biochemical recurrence (p = 0.001) and distant metastasis (p = 0.033) but not with cancer specific death (p = 0.6) or overall mortality (p = 0.3). Multivariable analysis showed no evidence of a significant association between the pT2 subclassification and biochemical recurrence (p = 0.4) or distant metastasis (p = 0.6). Multivariable analysis of cancer specific death and overall mortality was omitted due to lack of significance on univariate analysis. CONCLUSIONS: Subclassification of pT2 prostate cancer is not a prognostic indicator of survival related outcomes after radical prostatectomy. Our results validate the elimination of pT2 substages in the updated staging system.

In men who do not respond to initial radiation therapy, accurate knowledge of the site of cancer recurrence or persistence is necessary to understand treatment failure. We evaluated the pathologic characteristics of recurrent/persistent prostate cancer with tumor maps from the whole-mount slides of salvage radical prostatectomies performed between 2000 and 2014. Of 216 consecutive patients, detailed tumor maps were available for 77. Sixty-nine patients (90%) were found to have tumor in the apex, of which 46% occurred in the most apical 3mm. Fifty-three patients (69%) had tumors at a distance of =5mm from the urethra. Five patients had tumor directly involving the urethra, all of whom had urethral invasion at the apex. Seminal vesicle involvement was seen in 32 patients (42%), two of whom had tumor only in the seminal vesicles. Sixty-two patients (81%) had tumors in the distal apex, periurethral area, or seminal vesicles, that is, areas that are not routinely biopsied. Targeting these areas could improve the accuracy of biopsy when cancer recurrence is suspected. PATIENT SUMMARY: When recurrence is suspected, clinicians should include biopsy of the distal apex, areas surrounding the urethra, and seminal vesicles. This information will help tailor successful salvage treatments.

© 2019, Springer Nature America, Inc. Background: Tumor contact length (TCL) is defined as the extent of contact between prostate cancer and the prostatic capsule, and its predictive value for microscopic extraprostatic extension (EPE) has been reported. However, the impact of the zonal origin (anterior or posterior tumor) of the tumor on the diagnosis of EPE is controversial. Methods: We retrospectively analyzed the records of 233 consecutive patients who underwent preoperative MRI and radical prostatectomy. We designated their tumors as anterior or posterior, and evaluated the correlation between the TCL measured by MRI and microscopic EPE in the radical prostatectomy specimen. Then, we created the predicted probability curves for EPE versus TCL for anterior and posterior prostate cancer. Results: There were 109 patients (47%) with an anterior tumor and 124 patients (53%) with a posterior tumor. Postoperative pathological analysis confirmed pT3 in 18 patients (17%) with an anterior tumor and in 53 patients (43%) with a posterior tumor. Multivariate analysis demonstrated that the zonal origin of the tumor was an independent predictive factor for EPE. We developed separate probability curves of EPE versus TCL for anterior and posterior prostate cancer, which revealed that anterior tumors were less likely to invade the extraprostatic tissues. Among patients whose TCL was 10–20 mm, 9/32 patients (28%) with an anterior tumor had EPE compared with 24/45 patients (53%) with a posterior tumor (p = 0.036). The decision curve of this EPE predictive model had high clinical efficacy. Conclusions: Our results indicate that anterior tumors have more favorable pathological characteristics than posterior tumors with the same TCL measured by MRI. We constructed two separate predicted probability curves for EPE after discriminating anterior and posterior tumors, which will be useful for decision making in clinical practice.