Guo Wen Lin

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.

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.

Low dose of ketoconazole in patients with prostate adenocarcinoma resistant to pharmacological castration

OBJECTIVE • To assess the efficacy of ketoconazole in patients with castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS • From April 2008 to November 2009, 37 patients with CRPC have been treated with ketoconazole. The primary endpoint was the prostate-specific antigen (PSA) response; the secondary endpoints were progression-free survival and safety profile. • Ketoconazole was administered by oral route at a dose of 200 mg every 8 h continuous dosing until the onset of serious adverse events or disease progression. • The study was based on a two-step design with an interim efficacy analysis carried out on the first 12 patients accrued. RESULTS • Main characteristics of population were: median age 75 years (range 60-88); baseline mean PSA 28.8 ng/mL (4.3-1000); 30 patients previously challenged with at least two lines of hormone therapy; 15 patients previously treated with chemotherapy. • Biochemical responses accounted for: two complete responses (5%), six partial responses (16%), 13 patients with stable disease (35%), and 14 with progressive disease (38%). Of 15 patients resistant to chemotherapy, overall disease control (complete plus partial responses plus stable disease) was recorded in seven of them. • Treatment was feasible without inducing grade 3-4 adverse events. The most common grade 1-2 adverse events were asthenia (27%), vomiting (8%) and abdominal pain (8%). CONCLUSION • Treatment with low-dose ketoconazole is feasible and well tolerated. The efficacy was satisfactory in patients previously treated with chemotherapy.

Visceral fat accumulation is associated with different pathological subtypes of renal cell carcinoma (RCC): a multicentre study in China.

To investigate whether visceral obesity is associated with certain histological subtypes of renal cell carcinoma (RCC) in a multicentre Chinese cohort.

Association of glutathione S-transferase T1 and M1 polymorphisms with prostate cancer susceptibility in populations of Asian descent: a meta-analysis

Background Genetic polymorphism was hypothesized to be reason of variation in prostate cancer incidence among different racial group. Based on that published data on the association of prostate cancer susceptibility with polymorphisms in genes encoding Glutathione S-transferases (GSTs) were inconclusive, the aim of this study was to more precisely address the role of GSTs polymorphisms (especially, GSTT1 and GSTM1 deletions) on prostate cancer risk in Asian descent. Methods A meta-analysis including 8 articles with 711 cases and 1122 controls for GSTT1 and 1098 cases and 1588 controls for GSTM1 was performed. Results Significantly increased prostate cancer risk was found among subjects carrying GSTM1 null genotype (odds ratio (OR) = 1.403; 95% confidence interval (CI) = 1.088 – 1.808) but not among subjects carrying GSTT1 deletion genotype (OR = 0.959; 95%CI = 0.709 – 1.297). When stratified by country, the null genotype of GSTT1 neither increased nor decreased prostate cancer risk significantly in China (OR = 1.355; 95%CI = 0.895 – 2.049), Japan (OR = 0.812; 95%CI = 0.545 – 1.211), and Korea (OR = 1.056; 95%CI = 0.727 – 1.534). While significant association of elevated prostate cancer risk with GSTM1 deletion were found in China (OR = 1.665; 95%CI = 1.324 – .094) and Korea (OR = 1.914; 95%CI = 1.311 – 2.793) but not in Japan (OR = 0.980; 95%CI = 0.726 – 1.321). Conclusion In summary, this meta-analysis suggested that the null genotype of GSTM1 rather than GSTT1 may be involved in the etiology of prostate cancer in Asian population.

Oral etoposide and oral prednisone for the treatment of castration resistant prostate cancer

Treatment options for patients with castration‐resistant prostate cancer (CRPC) are limited. The purpose of our study was to investigate the safety and efficacy in terms of prostate‐specific antigen (PSA) response of a low‐dose oral combination of etoposide and prednisone in patients with CRPC. Thirty‐nine patients with prostate cancer (median age, 77.9 years) with progressive disease after standard hormonal therapy were enrolled. Etoposide (25 mg, twice daily) and prednisone (5 mg, twice daily) were administered orally. Each cycle comprised 21 consecutive days of treatment followed by a 7‐day drug holiday. All patients previously treated with an antiandrogen were required to undergo antiandrogen withdrawal prior to entry into the study. A total of 226 cycles were administered with a median of 6.7 cycles per patient (range, 1–18 cycles). Sixteen of 39 patients (41%) with elevated PSA levels at baseline achieved at least a 50% reduction in PSA levels. Median progression‐free survival for all patients was 5.9 months (range, 1–17 months). No Grade 4 toxicities were observed. The predominant toxicities were mucositis, nausea, fatigue, and anemia in twelve, nine, eight, and seven patients, respectively. Hematologic toxicity was infrequent, with no episodes of febrile neutropenia. The combination of low‐dose etoposide and prednisone is an efficacious and reasonably well‐tolerated oral regimen in the treatment of elderly patients with CRPC. This regimen can be easily administered in an outpatient setting and does not require frequent patient visits.

Development of a preliminary nomogram to predict progression of bone scan for castration-resistant prostate cancer.

The optimal time to perform bone scan to detect new metastasis during the castration-resistant prostate cancer (CRPC) stage remains undefined. This study attempted to identify predictors of progression of bone scan for CRPC, and use such information to develop a nomogram to predict the optimal time of examinations for bone scan. The analysis included 167 CRPC patients. Progression of bone lesion, as evaluated by bone scan, occurred in 64 (38.3%) cases. A logistic regression identified the following three risk factors: short time to prostate-specific antigen (PSA) progression, severe pain, and short PSA doubling time (PSADT) (P<0.05 for all). A nomogram model was constructed to predict progression of bone scan using time to PSA progression and severe pain as dichotomized variables and PSADT as a continuous variable. The result indicated that a predictive nomogram model showed a bootstrap-corrected concordance index of 0.762 and good calibration using the three readily available variables, and there were worse prognosis and higher progression rate of bone scan for patients with time to PSA progression <6.6 months, severe pain, and short PSADT (<2 months). In conclusion, short time to PSA progression, severe pain, and short PSADT are three risk factors of progression of bone scan for CRPC patients. The predictive nomogram model may be a valuable numerical assessment tool for patient consultation and treatment decision.