Prostate cancer with metastasis to the kidney is rare. Here, we report a case of prostate cancer metastasizing to renal cell carcinoma. A 67-year-old male presented with low back pain for 3 months, aggravated with persistent fever for 2 weeks in June 2018.Histopathological diagnosis of prostate adenocarcinoma was established. Meanwhile, contrasted CT of the abdomen showed a 3.0 cm×2.5 cm×2.5 cm enhanced solid mass on the lower pole of the right kidney. Nephron-sparing surgery was performed for the renal mass. Histopathology revealed a Grade 2 renal clear cell carcinoma with focal prostate carcinoma metastasis to the tumor. Then the patient received abiraterone acetate (AA) therapy. The patient did not encounter tumor recurrence in right kidney 18 months after surgery. However, PSA progression occurred 6 months later after AA therapy, then docetaxel chemotherapy and Sr 89 therapy were performed with limited efficacy. The patient died after 30 months.

Objective:To investigate the clinical characters and prognostic value of PSA flare and bone flare in metastatic castration resistant prostate cancer(mCRPC) patients received Abiterone acetate(AA) therapy.Methods:A retrospective study was conducted for 93 mCRPC patients treated with AA from Jul.2016 to Dec.2020. Mean age was (75.4±8.9)years, median PSA was 58.2 (16.4, 148.6)ng/ml. Patients received at least 6 months of AA treatment. PSA flare was defined as an increase of PSA after AA therapy followed by a decrease. Bone flare was defined as disease progression after 3 months of therapy, typically based on increased lesion intensity or number, and reevaluation 6-9 months later showed improvement in the scan. The clinical characters and prognostic value of the flare phenomenon was evaluated and analyzed respectively.Results:The median follow up time was 16 months(6, 54 months), fourteen patients showed PSA flare at first month after AA treatment, and median time of duration was 2 months(1, 7 months). The serum alkaline phosphatase (ALP) had a similar rising trend along with PSA flare[115.5(98.0, 198.5)U/L vs. 119.0(97.0, 288.8)U/L, P=0.016]. Seven patients showed bone flare and 3 cases co-existed with PSA flare. Multivariate Cox regression analysis indicated bone flare was an independent protective factor for progression free survival(PFS)( HR=0.117, 95% CI 0.015-0.895, P=0.039), PSA flare had no significant influence on PFS ( HR=1.314, 95% CI 0.554-3.121, P=0.536)and overall survival(OS)( HR=1.348, 95% CI 0.393-4.263, P=0.635). Log-rank test showed patients with bone flare had a longer PFS( P=0.016) and OS( P=0.047) compared with patients without bone flare. Conclusions:PSA flare always faded away after 2 months AA therapy and had no influence on PFS and OS. Bone flare maybe an indication for better prognosis.

Objective:To analyze the clinical characteristics and prognostic value of prostate-specific antigen (PSA) dynamic features in patients with metastatic castration resistant prostate cancer (mCRPC) received abiraterone acetate (AA) therapy.Methods:The data of 89 patients with mCRPC who received AA therapy from January 2017 to June 2021 in Shanghai Tongji Hospital were retrospectively reviewed. The age of patients was (75.7 ± 8.3) years old, median PSA before AA was 56.88 (19.31, 143.75) ng/ml. The PSA dynamic features included PSA nadir (PSAN) and PSAN time. PSAN was defined as the lowest value of PSA after treatment, and PSAN time was defined as time to PSAN after AA treatment. PSAN was divided into 3 groups: PSAN1 (<0.1 ng/ml), PSAN2 (0.1- 4.0 ng/ml) and PSAN3 (>4.0 ng/ml) groups. PSA response was defined as a maximum PSA decline rate ≥50%, and no PSA decline after treatment was defined as primary resistance. Cox regressions adjusted to clinical factors were performed to evaluate the influence of PSA dynamic features on patients' radiographic progression-free survival (rPFS) and overall survival (OS). Log-rank test was used to evaluate the survival time of patients in different PSAN groups. Receiver operator characteristic (ROC) curve and area under the curve (AUC) were performed to analyze the predictive value of PSA dynamic features on survival outcomes of patients.Results:The follow-up time was 17 (12, 23) months, and 75 (84.3%) patients showed PSA responses. The median PSAN was 1.82 (0.01, 11.70) ng/ml, median PSAN time was 5.0(3.0, 9.5)months. Multivariate Cox regression indicated that PSAN was an independent risk factor for rPFS ( PSAN2: HR=5.308, P=0.017; PSAN3: HR=13.209, P<0.001), and PSAN time ≥ 5 months( HR=0.309, P<0.001)was an independent protective factor for rPFS. Also, the PSAN3 was an independent risk factor for OS( HR=9.459, P=0.048). Log-rank test indicated that the rPFS of PSAN1 group (median not reached) was significantly longer than PSAN2 [median 13.0(95% CI 8.2-17.8) months, P=0.001] and PSAN3 [8.0 (95% CI 4.1-11.9) months, P<0.001] groups. ROC curve and AUC showed that PSAN had a higher predictive value in rPFS outcomes compared with T stage, metastatic disease volume, and Eastern Cooperative Oncology Group (ECOG) score (0.82 vs. 0.69, 0.68, 0.53, P<0.05). PSAN had a higher predictive value in OS outcomes than metastatic disease volume and ECOG(0.83 vs. 0.63, 0.58, P<0.05). Conclusions:Lower PSAN needs longer PSAN time. PSAN is an independent risk factor for rPFS and OS, and PSAN time is an independent protective factor for rPFS.