Novel nomogram developed for determining suitability of metastatic castration-resistant prostate cancer patients to receive maximum benefit from radium-223 dichloride treatment-Japanese Ra-223 Therapy in Prostate Cancer using Bone Scan Index (J-RAP-BSI) Trial.

PURPOSE: To develop a novel nomogram for determining radium-223 dichloride (Ra-223) treatment suitability for metastatic castration-resistant prostate cancer (mCRPC) patients. METHODS: This Japanese Ra-223 Therapy in Prostate Cancer using Bone Scan Index (J-RAP-BSI) Trial was a retrospective multicenter investigation enrolled 258 mCRPC patients in Japan with Ra-223 treatment between June 2016 and August 2020, with bone scintigraphy findings before treatment, clinical data, and survival outcome available. A nomogram was constructed using prognostic factors for overall survival (OS) based on a least absolute shrinkage and selection operator Cox regression model. A sub-analysis was also conducted for patients meeting European Medicines Agency (EMA) guidelines. RESULTS: Within a median of 17.4 months after initial Ra-223 treatment, 124 patients (48.1%) died from prostate cancer. Predictive factors included (1) sum of prior treatment history (score 0, never prior novel androgen receptor-targeted agents (ARTA) therapy, never prior taxane-based chemotherapy, and ever prior bisphosphonate/denosumab treatment), (2) Eastern Cooperative Oncology Group (ECOG) performance status, (3) prostate-specific antigen doubling time (PSADT), (4) hemoglobin, (5) lactate dehydrogenase (LDH), and (6) alkaline phosphatase (ALP) levels, and (7) automated bone scan index (aBSI) value based on bone scintigraphy. The nomogram using those factors showed good discrimination, with apparent and optimism-corrected Harrell's concordance index values of 0.748 and 0.734, respectively. Time-dependent area under the curve values at 1, 2, and 3 years were 0.771, 0.818, and 0.771, respectively. In 227 patients meeting EMA recommendation, the nomogram with seven factors showed good discrimination, with apparent and optimism-corrected Harrell's concordance index values of 0.722 and 0.704, respectively. Time-dependent area under the curve values at 1, 2, and 3 years were 0.747, 0.790, and 0.759, respectively. CONCLUSION: This novel nomogram including aBSI to select mCRPC patients to receive Ra-223 with significantly prolonged OS possibility was found suitable for assisting therapeutic decision-making, regardless of EMA recommendation.

Clinical, pathological, and therapeutic features of newly diagnosed prostate cancer predominantly detected by opportunistic PSA screening: A survey of Shiga Prefecture, Japan.

BACKGROUND: In all the prefectures of Japan, with the exception of Shiga Prefecture, more than half of local governments have an organized prostate-specific antigen (PSA) screening system in place. However, in the Shiga Prefecture, only a single city performed PSA screening over the time period of this survey. The purpose of the present study was to determine the clinical, pathological, and therapeutic features of newly diagnosed prostate cancer in localities where a formally organized screening system was almost entirely absent. METHODS: A multicenter observational study was conducted in the Shiga Prefecture, which has the lowest rate of population-based PSA-screening in Japan. Patients' age, initial PSA, reasons for PSA testing, Gleason score, clinical stage, and primary treatments were surveyed. We stratified patients according to the reasons for PSA measurement, and compared the differences between groups subject to organized versus opportunistic screening. RESULTS: In the 2 years 2012 and 2017, 984 newly diagnosed prostate cancer patients were analyzed. Of these, 954 (97%) were opportunistically tested (i.e., not as part of an organized screening system), with the remaining 29 (3%) measured as part of an organized screening program. Patients in the former group exhibited a higher initial PSA value than in the organized screening group (median: 11.49 vs. 5.67 ng/ml). They also had worse clinical features, including higher Gleason score and TNM stage. More patients in the organized screening group were treated curatively than in the nonorganized screening group in terms of the primary treatment. The results were similar in a subanalysis of the patients of age 50-69 years. CONCLUSIONS: Organized PSA screening contributes to increasing the number of patients diagnosed with early-stage cancer who can be treated curatively.

The location of the bladder neck in postoperative cystography predicts continence convalescence after radical prostatectomy.

BACKGROUND: This study was conducted to determine whether the location of the bladder neck in postoperative cystography predicts recovery of continence after radical prostatectomy. METHODS: Between 2008 and 2015, 203 patients who underwent laparoscopic radical prostatectomy (LRP, n = 99) and robot assisted radical prostatectomy (RARP, n = 104) were analyzed. The location of the bladder neck was visualized by postoperative routine cystography, and quantitative evaluation of the bladder neck position was performed according to the bladder neck to pubic symphysis (BNPS) ratio proposed by Olgin et al. (J Endourol, 2014). Recovery of continence was defined as no pad use or one security pad per day. To determine the predictive factors for recovery of continence at 1, 3, 6 and 12 months, several parameters were analyzed using logistic regression analysis, including age (≤68 vs. > 68, BMI (≤23.4 vs. > 23.4 kg/m2), surgical procedure (LRP vs. RARP), prostate volume (≤38 vs. > 38 mL), nerve-sparing technique, vesico-urethral anastomosis leakage, and BNPS ratio (≤0.59 vs. > 0.59). RESULTS: The mean postoperative follow-up was 1131 days (79-2880). At 1, 3, 6 and 12 months after surgery, continence recovery rates were 25, 53, 68 and 81%, respectively. Although older age (> 68) and RARP were significant risk factors for incontinence within 3 months, neither was significant after 6 months. A high BNPS ratio (> 0.59) was the only significant risk factor for the persistence of incontinence at all observation points, up to 12 months. CONCLUSIONS: A lower bladder neck position after prostatectomy predicts prolonged incontinence.

Urological laparoendoscopic single-site and reduced port surgery: A nationwide survey in Japan.

OBJECTIVES: To evaluate the current status of urological laparoendoscopic single-site and reduced port surgery in Japan. METHODS: Of the 152 institutions to which councilors of the Japanese Society of Endourology belong, 42 (28%) have carried out laparoendoscopic single-site and reduced port surgery. A total of 32 of these institutions agreed to participate in this survey. Patients who had undergone surgery between January 2008 and March 2014 were included in the present study. RESULTS: Overall, 1145 cases of laparoendoscopic single-site and reduced port surgery were recorded during the study period. The most frequent procedures were adrenalectomy and radical nephrectomy. Laparoendoscopic single-site and reduced port surgery represented 12% (872/7311) of all laparoscopic procedures carried out at participating institutions. The number of patients who underwent pyeloplasty, donor nephrectomy and simple nephrectomy tended to increase, whereas those who underwent adrenalectomy, radical nephrectomy and nephroureterectomy peaked in 2012, and then tended to decrease in 2013. The rates of conversion, perioperative and postoperative complications, were 2.7%, 2.2% and 4.5%, respectively. CONCLUSIONS: The number of laparoendoscopic single-site and reduced port urological surgeries in Japan has increased for benign indications, such as pyeloplasty, donor nephrectomy and simple nephrectomy. In contrast, procedures such as adrenalectomy and radical nephrectomy are trending down after reaching a peak in 2012. Overall, laparoendoscopic single-site and reduced port urological surgery in Japan is being safely carried out when compared with other reported series of laparoendoscopic single-site surgery and conventional laparoscopic surgery.

[Locally Advanced Ureteral Cancer Seen in an Ectopic Kidney : A Case Report].

An ectopic kidney is a common congenital anomaly of the urogenital system, but malignant tumor in an ectopic kidney has been rarely reported. We report a case of ureteral carcinoma arising from an ectopic kidney in an 83-year-old male. He visited a hospital complaining of gross hematuria. Computed tomography revealed right ectopic kidney, right ureteral tumor and bladder tumor around the right ureteral orifice. Transurethral resection of the bladder tumor was performed and histopathological diagnosis was urothelial carcinoma. He was referred to our clinic for surgery of the right ureteral tumor. We performed open right nephroureterectomy and partial cystectomy. The histopathological diagnosis was a high grade urothelial carcinoma of the right ureter, pT3N0. Four months postoperatively, there was no evidence of recurrence. We discuss the clinical and pathological features of the malignancy in an ectopic kidney.

[A Case of Synchronous Multiple Metastases in which the Origin Could Not Be Identified by Routine Examination].

A 67-year-old man presented at our hospital with severe edema on the left side of his neck, chest and brachial regions. He had a history of right radical nephrectomy due to renal cell carcinoma (RCC, clear cell subtype, stage II) 15 years earlier. Thereafter, metastases to the pancreatic tail and right lung, and left lung metastasis were removed at 8 years and 11 years, respectively, after the nephrectomy. Four years earlier, he had also undergone total gastrectomy for gastric carcinoma (poorly differentiated adenocarcinoma, stage IV) and subsequent maintenance chemotherapy for gastric carcinoma. Follow-up computed tomography (CT) disclosed bilateral lung metastases and a pancreatic head metastasis. Cytology of pleural effusion on admission suggested pleuritis carcinomatosa from RCC. Clinical diagnosis was bilateral lung and pancreatic head metastases, pleuritis carcinomatosa and left subclavian vein thrombosis due to RCC metastasis. Maintenance chemotherapy for gastric carcinoma was replaced by Sunitinib 50 mg for RCC but he died of progressive disease 20 days later. Immunohistochemical study of the tissue from autopsy revealed lung metastasis and pancreatic head metastasis from both RCC and gastric carcinoma as well as multiple visceral metastases, pleuritis carcinomatosa and left subclavian vein thrombosis due to gastric carcinoma. Cause of death was acute respiratory failure due to pulmonary tumor embolism and pulmonary edema. Immunohistochemical study from autopsy was able to reveal the exact diagnosis, and immunohistochemical studies may be helpful in diagnosing the exact origin of metastasis and selecting appropriate treatmentsin patientswith multiple cancers.

ENDOSCOPIC SHIELDING OF RECTOURETHRAL FISTULA AFTER LAPAROSCOPIC RADICAL PROSTATECTOMY; REPORT OF A CASE.

Rectourethral fistulais a relatively rare complication of radical prostatectomy but is extremely difficult to treat. We report a case with post-laparoscopic radical prostatectomy rectourethral fistula, treated with only endoscopic shielding.A 75-year-old man had undergone laparoscopic radical prostatectomy for prostate cancer, cT2cN0M0. Although there was no finding of rectal injury during the operation, pneumaturia, pyuria and diarrhea appeared at postoperative day 21 and diagnosed rectourethral fistula by colonoscopy and amidotrizoic acid enema. The fistula did not close spontaneously. Four months after the prostatectomy, we treated with endoscopic shielding by use of polyglycolic acid sheets and fibrin glue. The fistula have not recurred for 20 months after the endoscopic procedure.This method is simple and less-invasive for patients. We think it is worth trying this method before surgical management for narrow rectourethral fistula following radical prostatectomy.

TESTIS SPARING SURGERY FOR ADULT MATURE TERATOMA OF THE TESTIS; REPORT OF A CASE.

A 25-year-old man presented complaining of a painful, left scrotal swelling. He first noticed a mass in his left scrotum during childhood, but, in the absence of clinical symptoms, did not seek medical attention. We detected a left testicular tumor which was elastic, firm and smooth. Serum levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) were all within normal range. Magnetic resonance imaging (MRI) and ultrasound revealed a solid tumor with cysts accompanied by intracystic hemorrhage and calcified walls. From the above findings, the tumor was suspected to be benign and, we therefore planned testis-sparing surgery. We performed tumor enucleation under cold ischemia. Since an intraoperative frozen section revealed the tumor to be benign, we preserved the remaining testis as planned. The final pathologic diagnosis was a mature teratoma without a malignant germ cell component. Evidence of recurrence has not been observed five years after the operation. In conclusion, when a mature teratoma that has been present since prepuberty is suspected in an adult, testis-sparing surgery should be considered.

[A Female Paraurethral Leiomyoma Causing Urinary Retention: A Case Report].

Leiomyoma is a benign smooth muscle tumor which is rarely found in the paraurethral region. We report a case of paraurethral leiomyoma in a 44-year-old female who visited a clinic complaining of urinary retention. Magnetic resonance imaging revealed a 9 cm mass adjacent to the urethra. She was referred to our department. Transvaginal needle biopsy was performed and the histopathological diagnosis was leiomyoma. The mass was completely excised transperitoneally and transvaginally. The resected specimen was 8 × 7 × 4.5 cm in size and 194 g in weight. Histopathological diagnosis was leiomyoma and the tumor cells demonstrated immunoreactivity for estrogen receptors and progesterone receptors. Herpost operative course was uneventful and she gained normal voiding function. In a follow-up after 3 months, there was no evidence of recurrence. We discuss the clinical and pathological features of the paraurethral leiomyoma.

[PREPUBERTAL MATURE TERATOMA OF THE TESTIS MASQUERADING OF A SIMPLE CYST OF THE TESTIS].

A 6-month-old boy was referred to our hospital with left scrotal swelling. Scrotal ultrasound examination revealed a 2 cm cystic mass without solid component in left testicular parenchyma. Serum AFP, hCG and LDH levels were within normal limits. Although we suspected a simple cyst of the testis or a benign testicular tumor, the left testicle was explored via an inguinal incision in case of malignancy. Since intraoperative frozen section revealed benign, we preserved the remaining testis. The wall of cystic mass had a small solid lesion. The definitive pathological examination of the cyst wall showed mature teratoma including squamous epithelium, glandular epithelium of enteric type and cartilage. At 4 years of follow up, he was free of recurrence without testicular atrophy.

Prognostic nutritional index of early post-pembrolizumab therapy predicts long-term survival in patients with advanced urothelial carcinoma.

Pembrolizumab has been widely used to treat advanced urothelial carcinoma that has progressed after first-line platinum-based chemotherapy. Because its clinical benefits are limited, biomarkers that can predict a good response to pembrolizumab are required. The prognostic nutritional index (PNI), calculated using the serum albumin level and peripheral lymphocyte count, has been evaluated as a predictive biomarker in cancer immunotherapy. The present study investigated the application of PNI as a predictive biomarker for pembrolizumab response in patients with advanced urothelial cancer. A retrospective study was conducted on 34 patients treated with pembrolizumab at Shiga University of Medical Science Hospital between January 2018 and July 2022. The posttreatment PNI (post-PNI) was calculated within 2 months of starting pembrolizumab. The present study investigated the association between post-PNI and objective response, overall survival (OS) and progression-free survival (PFS). The patient cohort was stratified into two categories, high and low post-PNI groups, with a cutoff value of post-PNI at 40. The higher post-PNI group demonstrated a better disease control rate than the lower post-PNI group (complete response + partial response + stable disease, 75 vs. 21%, P=0.004). Regarding median OS, the higher post-PNI group exhibited a significantly longer survival time than the lower post-PNI group (23.1 vs. 2.9 months, P<0.001). Similarly, the higher post-PNI group exhibited a significantly longer PFS than the lower post-PNI group (10.2 vs.1.9 months, P<0.001). Multivariate analysis showed that a higher post-PNI value was an independent predictor for OS (hazard ratio, 0.04; 95% confidence interval, 0.01-0.14; P<0.001) and PFS (hazard ratio, 0.12; 95% confidence interval, 0.04-0.35; P<0.001). The present study indicated that the post-PNI was a predictor of favorable clinical outcomes in patients treated with pembrolizumab for advanced urothelial carcinoma.

Assessing Therapeutic Response to Radium-223 with an Automated Bone Scan Index among Metastatic Castration-Resistant Prostate Cancer Patients: Data from Patients in the J-RAP-BSI Trial.

To evaluate the usefulness of change in the automated bone scan index (aBSI) value derived from bone scintigraphy findings as an imaging biomarker for the assessment of treatment response and survival prediction in metastatic castration-resistant prostate cancer (mCRPC) patients treated with Ra-223. This study was a retrospective investigation of a Japanese cohort of 205 mCRPC patients who received Ra-223 in 14 hospitals between July 2016 and August 2020 and for whom bone scintigraphy before and after radium-223 treatment was available. Correlations of aBSI change, with changes in the serum markers alkaline phosphatase (ALP) and prostate-specific antigen (PSA) were evaluated. Additionally, the association of those changes with overall survival (OS) was assessed using the Cox proportional-hazards model and Kaplan-Meier curve results. Of the 205 patients enrolled, 165 (80.5%) completed six cycles of Ra-223. Following treatment, ALP decline (%ALP < 0%) was noted in 72.2% (148/205), aBSI decline (%aBSI < 0%) in 52.7% (108/205), and PSA decline (%PSA < 0%) in 27.8% (57/205). Furthermore, a reduction in both aBSI and ALP was seen in 87 (42.4%), a reduction in only ALP was seen in 61 (29.8%), a reduction in only aBSI was seen in 21 (10.2%), and in both aBSI and ALP increasing/stable (≥0%) was seen in 36 (17.6%) patients. Multiparametric analysis showed changes in PSA [hazard ratio (HR) 4.30, 95% confidence interval (CI) 2.32-8.77, p < 0.0001], aBSI (HR 2.22, 95%CI 1.43-3.59, p = 0.0003), and ALP (HR 2.06, 95%CI 1.35-3.14, p = 0.0008) as significant prognostic factors for OS. For mCRPC patients treated with Ra-223, aBSI change is useful as an imaging biomarker for treatment response assessment and survival prediction.

Population­based prostate­specific antigen screening for prostate cancer may have an indirect effect on early detection through opportunistic testing in Kusatsu City, Shiga, Japan.

Prostate cancer is the most common genitourinary cancer in men. Population-based serum prostate-specific antigen (PSA) testing is used to screen men for the early detection of asymptomatic prostate cancer. The present study compared the features of patients with prostate cancer in Kusatsu City, the only municipality in Shiga Prefecture of Japan to implement organized PSA screening, with those in other municipalities. The target population for organized PSA screening by mail invitation was men ≥50 years. Patients were pathologically diagnosed via prostate biopsy because of elevated serum PSA. This multicenter observational study was subsequently conducted in 14 hospitals. The following information was extracted from patient records: age, reason for PSA testing, initial PSA level, Gleason score, clinical stage, and place of residence. Risk classification was defined as low, intermediate, high, and advanced. Each patient was stratified according to their city/town. A total of 984 patients diagnosed with prostate cancer in Shiga in 2012 and 2017 were analyzed, of which 955 (97%) were opportunistically tested, with the remaining 29 (3%) assessed by organized screening. In Kusatsu, 93 patients were diagnosed, of whom 26 (28%) were detected by organized screening. By contrast, only three of 891 patients (0.3%) were detected by organized screening in other municipalities. Of patients in Kusatsu, cases identified by opportunistic testing had a higher initial PSA value (P=0.010) than those identified by organized screening. However, patients detected through opportunistic testing in Kusatsu City were younger (P=0.034), had a lower PSA value (P=0.001), and improved risk classification (P<0.001) than those in other municipalities. It was concluded that more patients were diagnosed with early-stage cancer by organized PSA screening. Furthermore, population-based PSA screening in Kusatsu City may have indirectly affected early detection, even by opportunistic testing.

[Small intestinal metastasis from renal cell carcinoma: a case report].

A 52-year-old man who had been treated with sorafenib for lung metastasis of renal cell carcinoma (RCC) presented to our hospital with iron-deficiency anemia. He had undergone right nephrectomy for RCC (clear cell carcinoma, pT1bN0M0) 11 years ago and lung metastasis developed 6 years after the surgery. Although upper gastrointestinal endoscopy and colonoscopy were performed on suspicion of gastrointestinal bleeding, no abnormality was detected. Capsule endoscopy and single balloon small bowel endoscopy disclosed a hemorrhagic submucosal tumor in the jejunum. Laparoscopic partial jejunectomy was performed, and pathological examination indicated metastatic RCC to the small intestine. After the operation, anemia improved but he died 8 months later because of intrabronchial bleeding from the metastatic lesion of the lung. Metastatic RCC of the small intestine is relatively rare, its diagnosis is difficult. Recently, new diagnostic tools such as capsule endoscopy and balloon-assisted endoscopy have been developed, and they are useful in diagnosing gastrointestinal bleeding (OGIB) which can not be detected by traditional enteroscopy. If patients with advanced RCC show gastrointestinal bleeding of uncertain etiology, we should perform aggressive examination of the digestive tract with these diagnostic tools.

Application of the indocyanine green fluorescence imaging method in laparoscopic resection of a solitary retroperitoneal metastasis of renal cell carcinoma: A case report.

Fluorescence image-guided surgery has improved intraoperative identification of anatomic structures including visualization of vascular anatomy. Herein, indocyanine green (ICG) fluorescence imaging was applied to identify of a recurrent small tumor of renal cell carcinoma (RCC) during laparoscopic surgery. The patient underwent left laparoscopic radical nephrectomy via the retroperitoneal approach for RCC (clear cell carcinoma, pT1bN0M0) at the age of 39 years. A solitary retroperitoneal mass (14 mm in diameter) was identified in a computed tomography scan 6 years after surgery. We performed laparoscopic resection with the application of the ICG angiography, because RCC is recognized as one of the most hypervascular cancers. The tumor was clearly visualized by fluorescence. Histopathological diagnosis of the resected tumor was recurrent RCC (low grade, G1). The patient remained free of disease at 2 years after surgery. The ICG fluorescence imaging would be a useful method for identification of metastatic small lesions of RCC during laparoscopic surgery.

Androgen receptor axis-targeted agents are not superior to conventional hormonal therapy for treatment of metastatic prostate cancer.

The present study aimed to use real-world Japanese data to compare the treatment outcome of conventional hormonal therapy to that of using androgen receptor axis-targeted (ARAT) agents for patients with metastatic castration-resistant prostate cancer. The overall survival between the conventional hormonal therapy group and the ARAT agent therapy group was compared using a group of 75 Japanese patients who were treated for metastatic castration-resistant prostate cancer. A subgroup analysis was carried out and the risk factors that affected overall survival (OS) were determined. The median OS from the time of prostate-specific antigen recurrence was 73.1 months in the ARAT group and 45.2 months in the conventional treatment group (P=0.414). Although OS tended to be slightly longer in the ARAT group, the difference between the groups was not significant. Subgroup analysis suggested that the therapeutic outcome of using ARAT agents tended to be less beneficial in patients who were older, and in those with a higher tumor volume or low Gleason grade. In conclusion, use of ARAT agents did not impart a significant survival benefit to patients with metastatic castration-resistant prostate cancer when compared with survival rates in response to conventional therapy. However, there was some clinical benefit when ARAT agents were used after patients developed castration-resistant prostate cancer. These findings suggest that up-front therapy using ARAT agents at the time of the initial hormone therapy can impart clinical benefit in Japanese patients with metastatic prostate cancer.

[Bladder metastasis of renal cell carcinoma : report of a case].

A 65-year-old man presented with gross hematuria in 2004. Computed tomography (CT) showed a left renal mass, and he underwent laparoscopic radical nephrectomy. Pathological diagnosis was clear cell carcinoma (pT2N0M0, G2＞G3). Four years later, a right adrenal tumor was disclosed by follow-up CT. Then laparoscopic adrenectomy was performed. Histology showed metastasis of the renal clear cell carcinoma. In 2009, he noticed gross hematuria, and cystoscopy revealed a 2cm solitary, non-papillary tumor at the anterior wall of the bladder. At the same time, small solitary liver metastasis (6 mm) was observed on abdominal CT. Transurethral resection of the bladder tumor and resection of liver tumor was performed, and pathological diagnosis was clear cell carcinoma both in vesical and hepatic masses. Nine months after the last surgery, he is living with no obvious tumor recurrence. To our knowledge this case is the 34th case of bladder metastasis from renal cell carcinoma in the Japanese literature. We reviewed literature and discuss the clinical features of bladder metastasis of renal cell carcinoma.

[Long-term disease stabilization by docetaxel plus estramustine for castration-resistant prostate cancer : report of a case].

Chemotherapy with docetaxcel (DTX) plus estramustine (EMP) for castration-resistant prostate cancer (CRPC) was started 30 months after the patient, a 65-year-old man, was diagnosed as having advanced prostate cancer cT3aN1M1 (OSS) with an initial PSA of 490 ng/ml. Prostate biopsy specimens revealed moderately differentiated adenocarcinoma, Gleason's sum 4＋5. He was treated with DTX 30 mg/m2 on day 2 and oral EMP 560 mg/day days 1-3 weekly for 3 out of 4 weeks. PSA at start of DTX plus EMP was 81.7 ng/ml, and that after 59 months was 66.6 ng/ml. No objective change in computed tomography and bone scan were observed. He also had no cancer-related symptoms and activity of daily life was good. Chemotherapy was interrupted twice because of pleural effusion and dyspnea by DTX, at 3 and 4 months, respectively, long-term disease stabilization was obtained by this treatment. Other adverse events including interstitial pneumonia, cardiovascular disorders and myelosuppression were not observed. He was maintained on the same chemotherapy. DTX plus EMP chemotherapy is an effective treatment for CRPC patients. Continuing this therapy it is important to survey and control adverse events caused by DTX and EMP carefully.

Long-Term Prostate-Specific Antigen Response on a Low-Dose Cabazitaxel Regimen for Metastatic Castration-Resistant Prostate Cancer: A Case Report.

BACKGROUND Cabazitaxel is a second-generation taxane approved for patients with metastatic castration-resistant prostate cancer (CRPC). Although cabazitaxel improves overall survival when used following docetaxel chemotherapy, duration of the clinical response is relatively short, and few patients achieve a long-term response. CASE REPORT A 71-year-old man with prostate adenocarcinoma with an initial prostate-specific antigen (PSA) level of 4956 ng/ml, Gleason score 4+5 and cTxN0M1b was referred to our department for treatment. Several therapeutic approaches, including androgen deprivation therapy, with a combination of bicalutamide and a luteinizing hormone-releasing hormone analogue, and 4 sequential hormonal therapies including flutamide, estramustine, enzalutamide, and abiraterone, all failed to prevent disease progression. Subsequently, after 5 cycles of docetaxel chemotherapy were also ineffective, cabazitaxel chemotherapy at a dose of 20 mg/m² together with prednisone and pegfilgrastim was initiated. The patient developed grade 4 thrombocytopenia during the first 4 cycles, and the dosage of cabazitaxel had to be tapered to 12.5 mg/m² by the fifth cycle. In subsequent cycles, the treatment was continued without grade 4 thrombocytopenia or any other toxicities ³grade 3. The patient achieved a long-term clinical response over 4 years and his PSA level continued to decrease, from 29.8 ng/ml at treatment initiation to a nadir of 2.0 ng/ml after the 60th cycle. CONCLUSIONS The present case is a rare example of a sustained response to low-dose cabazitaxel, and suggests its potential as a treatment option for metastatic CRPC patients. In our patient, this approach achieved a good clinical response with manageable toxicity over the long term.