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[en] In normal prostate epithelium the TMPRSS2 gene encoding a type II serine protease is directly regulated by male hormones through the androgen receptor. In prostate cancer ERG protooncogene frequently gains hormonal control by seizing gene regulatory elements of TMPRSS2 through genomic fusion events. Although, the androgenic activation of TMPRSS2 gene has been established, little is known about other elements that may interact with TMPRSS2 promoter sequences to modulate ERG expression in TMPRSS2-ERG gene fusion context. Comparative genomic analyses of the TMPRSS2 promoter upstream sequences and pathway analyses were performed by the Genomatix Software. NKX3.1 and ERG genes expressions were evaluated by immunoblot or by quantitative Real-Time PCR (qRT-PCR) assays in response to siRNA knockdown or heterologous expression. QRT-PCR assay was used for monitoring the gene expression levels of NKX3.1-regulated genes. Transcriptional regulatory function of NKX3.1 was assessed by luciferase assay. Recruitment of NKX3.1 to its cognate elements was monitored by Chromatin Immunoprecipitation assay. Comparative analysis of the TMPRSS2 promoter upstream sequences among different species revealed the conservation of binding sites for the androgen inducible NKX3.1 tumor suppressor. Defects of NKX3.1, such as, allelic loss, haploinsufficiency, attenuated expression or decreased protein stability represent established pathways in prostate tumorigenesis. We found that NKX3.1 directly binds to TMPRSS2 upstream sequences and negatively regulates the expression of the ERG protooncogene through the TMPRSS2-ERG gene fusion. These observations imply that the frequently noted loss-of-function of NKX3.1 cooperates with the activation of TMPRSS2-ERG fusions in prostate tumorigenesis
[en] Purpose: Radiation Therapy Oncology Group 85-31 was a randomized trial comparing radiotherapy (RT) alone vs. RT plus adjuvant androgen suppression for life in unfavorable-prognosis carcinoma of the prostate. We examined the impact of early initiation of salvage hormonal therapy (HT) in relapsing patients randomized to RT alone arm. Methods and Materials: Patients were divided into two groups: early salvage HT and late salvage HT. The early salvage group was defined as receiving HT with a prostate-specific antigen (PSA) level of less than 10 ng/mL, and the late salvage HT group had a PSA level of 10 ng/mL or greater. The outcomes were overall survival (OS), cause-specific mortality (CSM), and local failure (LF). The Kaplan-Meier estimation and log-rank test were used for OS, and the cumulative incidence estimation and Gray's test were used for CSM and LF. Proportional hazards regression models were used to compare the outcomes adjusted for other covariates. Results: The median follow-up times of surviving patients in the early and late salvage HT groups were about 11 and 13 years, respectively. The late salvage HT group had significantly more post-prostatectomy patients and patients with high Gleason scores. After adjustment for all covariates, OS was significantly longer in the early salvage HT group (hazard ratio, 1.5; p = 0.01). However, there were no statistically significant differences in LF or CSM between the groups. Conclusions: The early introduction of salvage HT resulted in improved OS but not improved CSM and LF. A randomized trial to define the optimal salvage hormonal timing is warranted in this group of patients with PSA recurrence after RT.
[en] Background: We studied whether hormonal therapy, (neo)adjuvant to radiotherapy for localized prostate cancer, is related to an increase in depression and whether this is caused by the hormonal therapy itself or by the relatively poor prognosis of patients who get (neo)adjuvant hormonal therapy. Methods: Between 2002 and 2005, 288 patients, irradiated for prostate cancer (T1-3N0M0), were studied prospectively in two clinics. In one clinic almost all patients received (neo)adjuvant androgen deprivation (Bicalutamide + Gosereline). In a second clinic hormonal therapy was prescribed mainly for high risk patients. This allowed us to separate the effects of hormonal therapy and the patient's prognosis. Results: During the course of hormonal therapy, depression was significantly heightened by both hormone use (p < 0.001) and poor prognosis (p < 0.01). After completion of hormonal therapy, poor prognosis continued to affect the depression score (p < 0.01). The increase was, however, small. Conclusions: Depression was mildly increased in patients receiving hormonal therapy. The increase appeared to be related to both the hormone therapy itself and the high risk status of patients. High risk status, with the associated poor prognosis, had a more sustained effect on depression. The rise was statistically significant, but was too small, however, to bear clinical significance.
[en] Androgen ablation has been the cornerstone of treating prostate cancers that have spread beyond the confines of the gland for over 50 years. It is achieved surgically by removal of the testes, or medically with gonadotropin releasing hormone (GnRH) analogues, exogenous estrogens, anti-androgens or adrenal enzyme synthesis inhibitors. Despite this long clinical experience, controversies remain as to when androgen ablation should be initiated - early vs. late; whether the simultaneous ablation of testicular and adrenal androgens should be considered 'standard' therapy; how long to continue treating patients who are responding - until progression or in an 'off and on' or 'intermittent' fashion; and, the value of changing in hormone treatments in patients who have failed primary therapy. In general, the duration of response to first line therapy ranges from 12-18 months although upwards of 20% of patients show no biochemical or clinical evidence of relapse within 5 year follow-up. The toxicities include hot flashes, a loss of libido, impotence, fatigue, gynecomastia, softening of the skin and beard, loss of muscle tone and personality changes. Treatment with anti-androgens such as flutamide, casodex or nilutamide alone, which do not lower serum testosterone levels, are similar in toxicities except for a lower frequency of impotence. However, in several studies, anti-androgen monotherapy has been shown to be inferior to those that lower serum testosterone levels. Our general approach is to offer combined androgen blockade as initial treatment and to monitor the patient serially. Those who show a normalization of PSA have a good prognosis, while those who do not are considered for alternative therapies
[en] Purpose: Trial RTOG 9202 was a phase 3 randomized trial designed to determine the optimal duration of androgen deprivation therapy (ADT) when combined with definitive radiation therapy (RT) in the treatment of locally advanced nonmetastatic adenocarcinoma of the prostate. Long-term follow-up results of this study now available are relevant to the management of this disease. Methods and Materials: Men (N=1554) with adenocarcinoma of the prostate (cT2c-T4, N0-Nx) with a prostate-specific antigen (PSA) <150 ng/mL and no evidence of distant metastasis were randomized (June 1992 to April 1995) to short-term ADT (STAD: 4 months of flutamide 250 mg 3 times per day and goserelin 3.6 mg per month) and definitive RT versus long-term ADT (LTAD: STAD with definitive RT plus an additional 24 months of monthly goserelin). Results: Among 1520 protocol-eligible and evaluable patients, the median follow-up time for this analysis was 19.6 years. In analysis adjusted for prognostic covariates, LTAD improved disease-free survival (29% relative reduction in failure rate, P<.0001), local progression (46% relative reduction, P=.02), distant metastases (36% relative reduction, P<.0001), disease-specific survival (30% relative reduction, P=.003), and overall survival (12% relative reduction, P=.03). Other-cause mortality (non–prostate cancer) did not differ (5% relative reduction, P=.48). Conclusions: LTAD and RT is superior to STAD and RT for the treatment of locally advanced nonmetastatic adenocarcinoma of the prostate and should be considered the standard of care.
[en] Purpose: To assess whether the PSA response to neoadjuvant androgen deprivation therapy (ADT) is associated with biochemical control in men treated with radiation therapy (RT) for prostate cancer. Methods and Materials: In a cohort of men treated with curative-intent RT for localized prostate cancer between 1988 and 2005, 117 men had PSA values after the first and second months of neoadjuvant ADT. Most men had intermediate-risk (45%) or high-risk (44%) disease. PSA halving time (PSAHT) was calculated by first order kinetics. Median RT dose was 76 Gy and median total duration of ADT was 4 months. Freedom from biochemical failure (FFBF, nadir + 2 definition) was analyzed by PSAHT and absolute PSA nadir before the start of RT. Results: Median follow-up was 45 months. Four-year FFBF was 89%. Median PSAHT was 2 weeks. A faster PSA decline (PSAHT ≤2 weeks) was associated with greater FFBF (96% vs. 81% for a PSAHT >2 weeks, p = 0.0110). Those within the fastest quartile of PSAHTs (≤ 10 days) achieved a FFBF of 100%. Among high-risk patients, a PSAHT ≤2 weeks achieved a 4-yr FFBF of 93% vs. 70% for those with PSAHT >2 weeks (p = 0.0508). Absolute PSA nadir was not associated with FFBF. On multivariable analysis, PSAHT (p = 0.0093) and Gleason score (p = 0.0320) were associated with FFBF, whereas T-stage (p = 0.7363) and initial PSA level (p = 0.9614) were not. Conclusions: For men treated with combined ADT and RT, PSA response to the first month of ADT may be a useful criterion for prognosis and treatment modification.
[en] Background and Aim: Androgen plays a fundamental role in the growth and differentiation of prostate. Androgen receptor (AR) expression may represent a potential marker of prognosis in prostate cancer. However, there have been variable results regarding its ability to predict clinical progression. Despite the oncogenic properties of DJ-1, its significance in prostate cancer development and progression is not well understood. This research shed some light on the possible role of immunohistochemical expression of DJ-1 in clinically localized prostatic carcinoma in relation to the established role of AR and other clinico pathologic parameters. Materials and Methods: The immunohistochemical expression of AR and DJ-1 was evaluated in 129 samples including benign hyperplasia (n = 60) and prostatic carcinoma (n = 69). Results: The mean value of AR immunostaining was significantly higher in prostatic carcinomas than in benign hyperplasia (P = 0.001). A significant inverse correlation was found between AR immunostaining and the grade of prostatic carcinomas. A significantly higher median DJ-1 score was found in prostatic carcinoma than in benign hyperplasia (P = 0.0001). There was a significant direct correlation between AR and DJ-1 score (P = 0.0001). AR is more sensitive in predicting prostatic carcinoma than DJ-1 but DJ-1 is more specific than AR. Conclusion: AR nuclear expression was consistently present in benign and adenocarcinoma epithelium. But, there may be limited clinical use for AR expression in localized carcinoma due to its constant heterogeneity. DJ-1 with its oncogenic properties, specificity for prostatic carcinoma and homogenous expression gives an ideal complementary role to AR in the detection and treatment of prostatic carcinomas.
[en] Purpose: To test the relative effect of neoadjuvant and adjuvant androgen deprivation on the radiation response of an androgen dependent tumor. Methods and Materials: The transplantable, androgen dependent, Shionogi adenocarcinoma was grown as allografts in the hind limbs of NCr/Sed (nu/nu) athymic nude mice. Bilateral orchiectomy was the chosen form of androgen deprivation. Groups of tumors were irradiated to graded tumor doses and then studied for durable tumor control. The radiation response was expressed as the radiation dose required to control 50% of the tumors (TCD50). The sequence of radiation and orchiectomy was studied. Results: When radiation was combined with orchiectomy the Shionogi tumor was significantly more likely to be controlled than when radiation was used alone. Orchiectomy 12 days prior to radiation (neoadjuvant therapy) produced a significantly greater decline in the TCD50 than when orchiectomy was used 1 day or 12 days after radiation (adjuvant therapy). If, before radiation, tumors were allowed to regrow after orchiectomy to their original size in an androgen independent fashion then the advantage was largely lost. Those tumors responding well to neoadjuvant orchiectomy (>50% volume decrease) were significantly more likely to be eradicated by radiation than those with a lesser response. Conclusion: When using combinations of androgen deprivation and radiation in the treatment of the Shionogi tumor, sequence and timing of the therapies are crucial to maximize the effect
[en] Purpose: To characterize the demographics and survival outcomes of localized prostate cancer patients who developed biochemical failure (BF) according to a prostate-specific antigen (PSA) nadir plus 2 ng/mL. Methods and Materials: We identified 375 prostate cancer patients who had undergone external beam radiotherapy without androgen deprivation therapy but with sufficient PSA data to study PSA kinetics. Of these patients, we identified 82 with BF. The pretreatment PSA velocity was calculated for each patient. Results: For the BF cohort, 26% were low-risk and 74% were intermediate- or high-risk patients. Of the 82 BF patients, 16 (20%) were noted to have both low-risk disease and a pretreatment low PSA velocity of ≤2 ng/mL/y (termed 'low-risk low-velocity' [LRLV]). The remaining BF patients had either intermediate- or high-risk features or a high PSA velocity >2 ng/mL/y (termed 'higher risk' [HR]). For patients who had BF, the LRLV group had a delayed median time to BF of 55 months compared with 33 months for the HR patients (p = 0.04). With a median clinical follow-up of 112 months, the 5-year overall survival rate was 100% for the LRLV BF patients vs. 84% for the HR patients (p = 0.02). Conclusions: We observed that LRLV BF patients represent a sizeable proportion of all patients with treatment failure. However, when comparing LRLV BF with HR BF patients, the former had significantly better overall survival and a longer interval to BF. This suggests that not all BF events are equivalent and emphasizes the challenges associated with using BF alone as a surrogate for a survival endpoint