Chun Guang Ma

Involvement of microRNA-21 in mediating chemo-resistance to docetaxel in androgen-independent prostate cancer PC3 cells.

AbstractAim:To investigate whether microRNA-21 was involved in mediating the chemoresistance of prostate cancer cells to docetaxel.Methods:A microarray technique was used to determine the miRNA profile in docetaxel-resistant PC3 cells. Real-time PCR was used to confirm the array results. miR-21 mimics and inhibitors were synthesized and introduced to cells using Lipofectamine 2000. Cell proliferation was examined with the CCK-8 assay. Luciferase reporter containing PDCD 3′UTR was constructed and the activity was detected by a dual luciferase assay. PDCD4 protein expression was evaluated using Western blot.Results:A docetaxel-resistant prostate cancer PC3 cell line (PC3R) was established . Using microarrays, miR-21 was found to be up-regulated in PC3R cells. Ectopic expression of miR-21 increased the resistance to docetaxel in PC3 wild type cells. In contrast, silencing of miR-21 in PC3R cells sensitized the cells to docetaxel. The IC50 values for miR-21-silencing cells and control cells were 28.31 and 35.89 nmol/L, respectively. PDCD4, a direct target gene of miR-21, could mediate chemoresistance to docetaxel in PC3 cells.Conclusion:Our findings suggest that miR-21 contributed to the resistance of PC3 cells to docetaxel, and that targeting miR-21 may offer a promising therapeutic approach in sensitizing prostate cancer to docetaxel treatment.

Activation of the mammalian target of rapamycin signalling pathway in prostate cancer and its association with patient clinicopathological characteristics

To evaluate the activation level of the mammalian target of rapamycin (mTOR) signalling pathway in Chinese patients with prostate cancer, as this pathway is over‐activated in many human cancers and is an attractive target for cancer therapy.

Tumor cytoreduction results in better response to androgen ablation-a preliminary report of palliative transurethral resection of the prostate in metastatic hormone sensitive prostate cancer

OBJECTIVES To investigate the oncologic influence of transurethral resection of the prostate (TURP) as a cytoreductive surgery in metastatic hormone sensitive prostate cancer (mHSPC), in the setting of continuous complete androgen blockade (CAB). MATERIALS AND METHODS Medical histories of 146 consecutive Chinese males with newly diagnosed mHSPC, registered in our institution in 2006 and 2007, were reviewed. All of these patients received CAB as initial systematic therapy. Demographics and cancer control outcomes from 39 mHSPC patients who underwent TURP for a relief of bladder outlet obstruction were compared with those of the other 107 who received CAB only when they were still hormone-sensitive. Median follow-up was 15 months (3 to 27 months). RESULTS Age at diagnosis, baseline PSA, and biopsy Gleason score were comparable between the 2 groups. Patients who underwent a TURP had lower PSA nadir (median 0.15 ng/ml vs. 0.82 ng/ml, P = 0.015) and longer time to PSA nadir (11.2 months vs. 6.4 months, P < 0.001). More patients in the non-TURP group developed hormone refractory prostate cancer (P = 0.007). The TURP group had a tendency towards longer disease-specific survival and overall survival (24.4 months vs. 24.1 months and 24.4 months vs. 22.9 months, respectively), though this did not reach statistical significance. CONCLUSIONS TURP resulted in a better and more prolonged response to hormone therapy in mHSPC, with a trend towards positive influence in disease specific survival and overall survival. To date, our preliminary report is the first study regarding long-term survival of cytoreductive surgery in mHSPC, and further investigations are warranted.

Prospectively Packaged Ilioinguinal Lymphadenectomy for Penile Cancer: The Disseminative Pattern of Lymph Node Metastasis

PURPOSE We prospectively evaluated the disseminative pattern of lymph node metastasis in penile cancer cases using packaged lymphadenectomy. In addition, we analyzed prognostic factors of the extent of lymph node metastasis. MATERIALS AND METHODS Packaged inguinal lymphadenectomy was performed in 46 patients. A total of 24 patients with 1 or more positive inguinal lymph nodes underwent packaged iliac lymphadenectomy. Inguinal lymphadenectomy was divided into 3 packages, including medial inguinal, lateral inguinal and Cloquets node packages. Medial and lateral inguinal packages were separated by the lateral surface of the femoral artery and the saphenous vein. Iliac lymphadenectomy was divided into 3 packages, including external iliac, obturator and common iliac packages. Clinicopathological features of the primary tumor and lymph nodes were correlated with the extent of lymph node metastasis. RESULTS Of 92 groin basins 27 cases of inguinal lymphadenectomy and 7 of iliac lymphadenectomy had lymph node metastasis. Medial inguinal and external iliac packages were the most common involved regions in inguinal and iliac lymphadenectomy cases, respectively. No extended lymph node metastasis was observed in the absence of positive lymph nodes in the medial inguinal package. In groin basins with lymph node metastasis in the medial inguinal package extranodal extension was a significant predictor of extended lymph node metastasis. Cloquets node was associated with iliac lymph node metastasis on univariate analysis. However, it was of limited predictive value in patients with 1 or 2 positive inguinal lymph nodes. CONCLUSIONS The medial inguinal package defined in our study was the first involved lymph node region in penile cancer cases. Extranodal extension was an important predictor of extended lymph node metastasis beyond the medial inguinal package.

Prognostic factors in Chinese patients with metastatic castration-resistant prostate cancer treated with docetaxel-based chemotherapy

This study aims to evaluate the potential value of patient characteristics in predicting overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel-based thermotherapy. A total of 115 patients with mCRPC undergoing a docetaxel q3w regimen were enrolled in this study. A survival analysis was performed using the Kaplan-Meier method. Cox proportional hazards models were used to evaluate the prognostic value of all covariates for OS. OS was also analysed after stratifying patients according to the results of multivariate analysis. The median OS for the entire cohort was 17.0 months. The multivariate analysis showed that the prostate-specific antigen doubling time (PSADT), baseline haemoglobin (Hb) concentration, alkaline phosphatase (ALP) concentration, cycles of chemotherapy and time to castration resistance were independent prognostic factors of OS. According to the presence of PSADT <46.3 days and baseline ALP ≥ 110 IU l(-1), all patients were divided into three risk groups: low-risk group (no risk factors), intermediate-risk group (one risk factor) and high-risk group (two risk factors). Median OSs for patients in low-, intermediate- and high-risk groups were 28.0 months (95% CI: 23.8-32.2), 21.0 months (95% CI: 18.9-23.1) and 11.0 months (95% CI: 7.6-14.4), respectively (P<0.001). In conclusion, PSADT, baseline Hb concentration, ALP concentration, cycles of chemotherapy and time to castration resistance were independent prognostic factors of OS in Chinese patients with mCRPC treated with docetaxel. PSADT combined with the baseline ALP concentration could be a useful risk stratification parameter for evaluating survival outcomes.

Prostate-specific antigen half-life: A new predictor of progression-free survival and overall survival in Chinese prostate cancer patients

We investigated the potential value of prostate-specific antigen half-life (PSAHL) and decreasing velocity (PSAVd) to predict progression-free survival (PFS) and overall survival (OS) in Chinese patients with prostate cancer. A total of 153 patients treated with hormonal therapy were included in the study. Of these, 78 patients progressed to hormone-refractory prostate cancer (HRPC) and 24 patients died by the end of follow-up. PSAHL was defined as the time during which prostate-specific antigen (PSA) concentration became half of the initial value during the first hormonal therapy. PSAVd reflected the decreasing velocity of PSA during the first hormonal therapy. PFS was defined as the interval from the beginning of hormonal therapy to HRPC. Cox proportional hazards regression analysis was used to evaluate whether PSAHL and PSAVd were significantly associated with PFS and OS. The median PSAHL and PSAVd were 0.50 months and 33.8 ng mL(-1) per month. The median PFS and OS were 22.7 months (95% confidence interval [CI], 22.0-29.6 months) and 43.5 months (95% CI, 37.9-48.4 months), respectively. On univariate and multivariate analysis, long PSAHL (> 0.5 months), metastatic disease, high biopsy Gleason scores (>or= 8) and high nadir PSA (> 0.4 ng mL(-1)) were all found to be significantly associated with short PFS. Long PSAHL, high nadir PSA and short PSA doubling time (PSADT <or= 2.0 months) were significantly associated with short OS. There were no significant relationships between PSAVd and either PFS or OS. Thus, PSAHL is a promising new independent predictor of survival. Patients with long PSAHL were identified as those at high risk for a relatively short PFS and OS.

External validation of the prostate cancer prevention trial and the European randomized study of screening for prostate cancer risk calculators in a Chinese cohort

Several prediction models have been developed to estimate the outcomes of prostate biopsies. Most of these tools were designed for use with Western populations and have not been validated across different ethnic groups. Therefore, we evaluated the predictive value of the Prostate Cancer Prevention Trial (PCPT) and the European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculators in a Chinese cohort. Clinicopathological information was obtained from 495 Chinese men who had undergone extended prostate biopsies between January 2009 and March 2011. The estimated probabilities of prostate cancer and high-grade disease (Gleason >6) were calculated using the PCPT and ERSPC risk calculators. Overall measures, discrimination, calibration and clinical usefulness were assessed for the model evaluation. Of these patients, 28.7% were diagnosed with prostate cancer and 19.4% had high-grade disease. Compared to the PCPT model and the prostate-specific antigen (PSA) threshold of 4 ng ml(-1), the ERSPC risk calculator exhibited better discriminative ability for predicting positive biopsies and high-grade disease (the area under the curve was 0.831 and 0.852, respectively, P<0.01 for both). Decision curve analysis also suggested the favourable clinical utility of the ERSPC calculator in the validation dataset. Both prediction models demonstrated miscalibration: the risk of prostate cancer and high-grade disease was overestimated by approximately 20% for a wide range of predicted probabilities. In conclusion, the ERSPC risk calculator outperformed both the PCPT model and the PSA threshold of 4 ng ml(-1) in predicting prostate cancer and high-grade disease in Chinese patients. However, the prediction tools derived from Western men significantly overestimated the probability of prostate cancer and high-grade disease compared to the outcomes of biopsies in a Chinese cohort.

A Phase II trial of dosage escalation of sorafenib in Asian patients with metastatic renal cell carcinoma

AIM To investigate the role of sorafenib dosage escalation in Asian patients with metastatic renal cell carcinoma that had progressed after routine dosages. PATIENTS & METHODS Sorafenib dosage escalation to 600 or 800 mg twice a day was offered to 41 patients with metastatic renal cell carcinoma who had progressed on normal dosages. Clinical outcome, toxicity and favorable clinical covariables for progression-free survival (PFS) were evaluated. RESULTS The median PFS with dosage-escalated therapy was 7 months. Drug-related adverse events were tolerable. The pre-escalation Karnofsky performance status, serum calcium concentration, neutrophil/lymphocyte ratio, PFS and the highest toxicity grade at the routine dosage were associated with a longer PFS in the dosage-escalation period. CONCLUSION Sorafenib dosage escalation was efficacious and tolerable in Asian patients. TRIAL REGISTRATION Chinese Clinical Trial Registry (no. ChiCTR-ONRC-12002088).

The prognostic factors of effective ketoconazole treatment for metastatic castration-resistant prostate cancer: who can benefit from ketoconazole therapy?

We investigated the prognostic value of some variables of effective ketoconazole treatment for metastatic castration-resistant prostate cancer (mCRPC). In total, 163 patients with mCRPC were eligible, receiving ketoconazole 200-400 mg three times daily with replacement doses of prednisone. Progression-free survival (PFS) was calculated from the beginning of the ketoconazole therapy to the onset of disease progression. The prognostic value of different variables for PFS was assessed by Cox regression analysis. The median PFS was 2.6 months (0.5-8.6 months) for these patients. The serum testosterone level changed during therapy, which decreased when the prostate-specific antigen (PSA) declined; the serum testosterone level increased as the levels of PSA relapsed. The median PFS values for patients associated with different factors were the following: 1.4 and 3.5 months for a nadir PSA of ≥ 0.2 and <0.2 ng ml(-1), respectively (hazard rate (HR)=4.767, P<0.001); 3.1 and 1.6 months for a baseline testosterone of ≥ 0.1 and <0.1 ng ml(-1), respectively (HR=2.865, P=0.012); 2.8 and 1.9 months for a baseline haemoglobin of ≥ 120 and <120 g l(-1), respectively (HR=1.605, P<0.001); and 3.0 and 1.9 months for a PSA doubling time (PSADT) of ≥ 2.0 and <2.0 months, respectively (HR=1.454, P=0.017). A risk model was constructed according to the four factors that divided patients into three subgroups of low risk (0-1 factors), moderate risk (2 factors) and high risk (3-4 factors) with PFS values of 3.6, 3.0 and 1.4 months, respectively (HR=1.619, P<0.001). A nadir PSA of ≥ 0.2 ng ml(-1), a baseline testosterone of <0.1 ng ml(-1), a baseline haemoglobin of <120 g l(-1) and a PSADT of <2 months were associated with a poor PFS. This risk model could provide evidence to predict the survival benefit of ketoconazole therapy.

Human epidermal growth factor receptor type 2 protein expression in Chinese metastatic prostate cancer patients correlates with cancer specific survival and increases after exposure to hormonal therapy

AIM To investigate human epidermal growth factor receptor type 2 (HER2) protein expression and gene amplification in Chinese metastatic prostate cancer patients and their potential value as prognostic factors. METHODS Immunohistochemistry (IHC) was performed to investigate HER2 protein expression in prostate biopsy specimens from 104 Chinese metastatic prostate cancer patients. After 3-11 months of hormonal therapy, 12 patients underwent transurethral resection of the prostate (TURP). HER2 protein expression of TURP specimens was compared with that of the original biopsy specimens. Of these, 10 biopsy and 4 TURP specimens with HER2 IHC staining scores >or=2+ were investigated for HER2 gene amplification status by fluorescent in situ hybridization (FISH). RESULTS Of the 104 prostate biopsy specimens, HER2 protein expression was 0, 1+, 2+ and 3+ in 49 (47.1%), 45 (43.3%), 8 (7.7%) and 2 (1.9%) cases, respectively. There was a significant association between HER2 expression and Gleason score (P = 0.026). HER2 protein expression of prostate cancer tissues increased in 33.3% of patients after hormonal therapy. None of the 14 specimens with HER2 IHC scores >or= 2+ showed HER2 gene amplification. Patients with HER2 scores >or= 2+ had a significantly higher chance of dying from prostate cancer than those with HER2 scores of 0 (P = 0.004) and 1+ (P = 0.034). Multivariate Cox regression analysis showed that HER2 protein expression intensity was an independent predictor of cancer-related death (P = 0.039). CONCLUSION An HER2 IHC score >or= 2+ should be defined as HER2 protein overexpression in prostate cancer. Overexpression of HER2 protein in cancer tissue might suggest an increased risk of dying from prostate cancer. HER2 protein expression increases in some individual patients after hormonal therapy.