Can 68 Ga-PSMA positron emission tomography and multiparametric MRI guide treatment for biochemical recurrence after radical prostatectomy?

OBJECTIVE: To evaluate the role of multiparametric magnetic resonance imaging (mpMRI) and Gallium-68 (68 Ga)-prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) in guiding salvage therapy for patients with biochemical recurrence (BCR) post-radical prostatectomy. PATIENTS AND METHODS: Patients were evaluated with paired mpMRI and 68 Ga-PSMA PET/CT scans for BCR (prostate-specific antigen [PSA] >0.2 ng/mL). Patient, tumour, PSA and imaging characteristics were analysed with descriptive statistics. RESULTS: A total of 117 patients underwent paired scans to investigate BCR, of whom 53.0% (62/117) had detectable lesions on initial scans and 47.0% (55/117) did not. Of those without detectable lesions, 8/55 patients proceeded to immediate salvage radiotherapy (sRT) and 47/55 were observed. Of patients with negative imaging who were initially observed, 46.8% (22/47) did not reach threshold for repeat imaging, while 53.2% were rescanned due to rising PSA levels. Of these rescanned patients, 31.9% (15/47) were spared sRT due to proven distant disease, or due to absence of disease on repeat imaging. Of the original 117 patients, 53 (45.3%) were spared early sRT due to absence of disease on imaging or presence of distant disease, while those undergoing delayed sRT still maintained good PSA responses. Of note, patients with high-risk features who underwent sRT despite negative imaging demonstrated satisfactory PSA responses to sRT. Study limitations include the observational design and absence of cause-specific or overall survival data. CONCLUSION: Our findings support the use of mpMRI and 68 Ga-PSMA PET/CT in guiding timing and necessity of salvage therapy tailored to detected lesions, with potential to reduce unnecessary sRT-related morbidity. Larger or randomized trials are warranted to validate this.

Defining Diagnostic Criteria for Prostatic Ductal Adenocarcinoma at Multiparametric MRI.

Background Prostatic ductal adenocarcinoma (DAC) is an aggressive histologic variant of prostate cancer that often warrants multimodal therapy and poses a significant diagnostic challenge clinically and at imaging. Purpose To develop multiparametric MRI criteria to define DAC and to assess their diagnostic performance in differentiating DAC from prostatic acinar adenocarcinoma (PAC). Materials and Methods Men with histologically proven DAC who had multiparametric MRI before radical prostatectomy were retrospectively identified from January 2011 through November 2018. MRI features were predefined using a subset of nine DACs and then compared for men with peripheral-zone DACs 1 cm or greater in size and men with matched biopsy-confirmed International Society of Urological Pathology grade group 4-5 PAC, by four independent radiologists blinded to the pathologic diagnosis. Diagnostic performance was determined by consensus read. Patient and tumor characteristics were compared by using the Fisher test, t-tests, and Mann-Whitney U test. Agreement (Cohen κ) and sensitivity analyses were also performed. Results There were 59 men with DAC (median age, 63 years [interquartile range, 56, 67 years]) and 59 men with PAC (median age, 64 years [interquartile range, 59, 69 years]). Predefined MRI features, including intermediate T2 signal, well-defined margin, lobulation, and hypointense rim, were detected in a higher proportion of DACs than PACs (76% [45 of 59] vs 5% [three of 59]; P < .001). On consensus reading, the presence of three or more features demonstrated 76% sensitivity, 94% specificity, 94% positive predictive value [PPV], and 80% negative predictive value [NPV] for all DACs and 100% sensitivity, 95% specificity, 81% PPV, and 100% NPV for pure DACs. The DACs and PACs showed no difference in contrast enhancement (100% vs 100%; P >.99, median T2 signal intensity (254 vs 230; P = .99), or apparent diffusion coefficient (median, 677 10-6 mm2/sec vs 685 10-6 mm2/sec; P = .73). Conclusion The presence of intermediate T2 signal, well-defined margin, lobulation, and/or hypointense rim, together with restricted diffusion and contrast enhancement at multiparametric MRI of the prostate, suggests prostatic ductal adenocarcinoma rather than prostatic acinar adenocarcinoma. © RSNA, 2022 Online supplemental material is available for this article.

The obesity paradox: defining the impact of body mass index and diabetes mellitus for patients with non-muscle-invasive bladder cancer treated with bacillus Calmette-Guérin.

OBJECTIVES: To evaluate if the obesity paradox, wherein obesity portends worse overall prognosis for a disease but improved outcomes for patients receiving immunotherapy, exists for patients receiving bacillus Calmette-Guérin (BCG) in a contemporary cohort. PATIENTS AND METHODS: We performed an Institutional Review Board-approved database review to identify patients with non-muscle-invasive bladder cancer (NMIBC) completing at least an induction course of BCG. Clinicopathological variables collected included: body mass index (BMI), medications, and diabetes mellitus (DM). Outcomes of interest included: recurrence-free (RFS), progression-free (PFS), cancer-specific (CSS), and overall survival (OS). Univariate and multivariate modelling were used to evaluate the association between outcomes and clinical factors. RESULTS: A total of 579 patients (median follow-up 4.6 years) received BCG induction for NMIBC; 90% had high-grade disease (47.2% clinical stage T1). In all, 75.7% of patients were overweight or obese and 18% had DM. Aspirin, statins, metformin and ß-blockers were used in 34%, 42%, 11%, and 29% of patients, respectively. Overweight and obese patients had improved PFS, CSS and OS. DM was associated with worse RFS. Medications of interest had no association with outcomes. CONCLUSION: Elevated BMI is associated with improved outcomes in patients with NMIBC treated with BCG immunotherapy. Patients with DM are at increased risk of recurrence. These findings support a potential obesity paradox in bladder cancer. Evaluation of the underlying mechanism and the role of global patient assessment, counselling, and risk factor modification are warranted.

Patterns of metastases of prostatic ductal adenocarcinoma.

BACKGROUND: The current study was conducted to investigate the patterns of metastases in men with metastatic prostatic ductal adenocarcinoma (DAC) and recurrence patterns after therapy. METHODS: All patients with a new diagnosis of DAC with de novo metastases and those with localized disease who developed metastases after treatment and were treated at the study institution from January 2005 to November 2018 were included. All patient and tumor characteristics and outcome data were collected. RESULTS: A total of 164 patients (37.7%) had metastatic DAC, including 112 with de novo metastases and 52 who developed metastases after treatment. Men with de novo metastases were found to have a significantly higher median prostate-specific antigen level and International Society of Urological Pathology grade but a lower cT3 and/or T4 classification compared with those with metastases that developed after treatment (all P < .05). Approximately 87% of men with de novo metastases progressed despite multiple systemic therapies, 37.6% required intervention for the palliation of symptoms, and 10.1% responded to systemic therapy and underwent treatment of the primary tumor. Men with de novo metastatic DAC and those who developed metastases after treatment had multiple metastatic sites (including bone and viscera), with higher rates of lung metastases noted in the posttreatment group (23.2% vs 44.2%; P = .01). A total of 45 patients who were treated with curative intent developed metastases at a median of 22 months (range, 0.9-74.8 months) after treatment, at low prostate-specific antigen levels (median, 4.4 ng/mL [interquartile range, 1.7-11.1 ng/mL]). CONCLUSIONS: The current study described the metastatic patterns of DAC in both patients with de novo metastatic disease and those who later progress to metastases. Men receiving treatment for DAC with curative intent require stringent long-term follow-up with imaging modalities, including chest imaging given the predilection toward lung metastases noted among these patients.

Can online support groups address psychological morbidity of cancer patients? An artificial intelligence based investigation of prostate cancer trajectories.

BACKGROUND: Online Cancer Support Groups (OCSG) are becoming an increasingly vital source of information, experiences and empowerment for patients with cancer. Despite significant contributions to physical, psychological and emotional wellbeing of patients, OCSG are yet to be formally recognised and used in multidisciplinary cancer support programs. This study highlights the opportunity of using Artificial Intelligence (AI) in OCSG to address psychological morbidity, with supporting empirical evidence from prostate cancer (PCa) patients. METHODS: A validated framework of AI techniques and Natural Language Processing (NLP) methods, was used to investigate PCa patient activities based on conversations in ten international OCSG (18,496 patients- 277,805 conversations). The specific focus was on activities that indicate psychological morbidity; the reasons for joining OCSG, deep emotions and the variation from joining through to milestones in the cancer trajectory. Comparative analyses were conducted using t-tests, One-way ANOVA and Tukey-Kramer post-hoc analysis. FINDINGS: PCa patients joined OCSG at four key phases of psychological distress; diagnosis, treatment, side-effects, and recurrence, the majority group was 'treatment' (61.72%). The four groups varied in expression of the intense emotional burden of cancer. The 'side-effects' group expressed increased negative emotions during the first month compared to other groups (p<0.01). A comparison of pre-treatment vs post-treatment emotions showed that joining pre-treatment had significantly lower negative emotions after 12-months compared to post-treatment (p<0.05). Long-term deep emotion analysis reveals that all groups except 'recurrence' improved in emotional wellbeing. CONCLUSION: This is the first empirical study of psychological morbidity and deep emotions expressed by men with a new diagnosis of cancer, using AI. PCa patients joining pre-treatment had improved emotions, and long-term participation in OCSG led to an increase in emotional wellbeing, indicating a decrease in psychological distress. It is opportune to further investigate AI in OCSG for early psychological intervention as an adjunct to conventional intervention programs.

Management of cT4 Prostate Cancer.

While radiotherapy with androgen deprivation therapy is the current standard of care for the treatment of stage cT4 prostate cancer (PC), surgery may also be an appropriate option in selected patients as part of a multimodal approach. The role and the sequence with which to optimize therapy combinations in this setting are still unknown. This mini review summarizes the current evidence for management of cT4 PC. PATIENT SUMMARY: This mini review examines current evidence for the treatment options for locally advanced prostate cancer. The role of surgery in these patients can be considered as part of a combination treatment strategy along with other modalities such as radiotherapy and hormone therapy.

Treatment of the Primary Tumor in Metastatic Hormone-sensitive Prostate Cancer: Not Yet Ready for Prime Time as the Standard of Care.

Retrospective studies in selected patients have demonstrated a survival benefit with prostatectomy or radiotherapy (RT) of the primary tumor in metastatic hormone-sensitive prostate cancer (mHSPC). However, there is currently not enough evidence to recommend RT to the primary tumor as the standard of care for patients treated with androgen deprivation therapy plus abiraterone or docetaxel for low-volume mHSPC.

Metformin may offer no protective effect in men undergoing external beam radiation therapy for prostate cancer.

OBJECTIVES: To assess whether metformin reduces radio-resistance and increases survival in men undergoing external beam radiation therapy (EBRT) for prostate cancer (PCa), and to determine its effect on hypoxia inducible factor 1-α (HIF1α). PATIENTS AND METHODS: All patients treated with curative intent with EBRT for PCa at a major cancer centre between 2000 and 2007 were included in this study. The outcome measures of time to biochemical failure (BF), metastasis, PCa-specific mortality and overall survival (OS) were analysed in those taking metformin vs those not, using competing risk and Cox regression models. To determine metformin's effect on HIF1α expression and survival in vitro, PC3 cells with high basal HIF1α levels were subjected to increasing doses of metformin after H2 O2 -induced oxidative stress. RESULTS: A total of 2055 eligible cases, including 113 who were on metformin, were identified, with a median follow-up of 95.7 months. There were no differences in age, initial prostate-specific antigen level, Gleason score, T-stage, D'Amico risk class or duration of androgen deprivation therapy (ADT) between patients who were or were not on metformin. Treatment with metformin did not result in any apparent improvement in time to BF, time to metastasis detection or OS, but there was a 1.5-fold increase in PCa-specific deaths (P = 0.045) in patients on metformin and ADT when adjusted for cancer risk and comorbidities. When comparing patients on high-dose metformin (>1 g/d) with those on low-dose metformin (≤1 g), there was no difference in either time to metastases or time to BF. In vitro metformin at a high concentration of 100 µM did not reduce HIF1α expression, nor did metformin affect the PC3 cell survival when exposed to oxidative stress (H2 O2 ). CONCLUSIONS: No association was found between the use of metformin and time to metastasis detection, time to BF or OS in patients undergoing radiation therapy with or without ADT for PCa. In vitro, low therapeutic concentrations of metformin had no effect on HIF1α, and this observation could explain the conflicting evidence for the effectiveness of metformin in men undergoing EBRT for PCa. Higher, more toxic doses of metformin may be required to inhibit the mammalian target of rapamycin-HIF1α pathway in this patient group.

Survival Outcomes in Renal Transplant Recipients With Renal Cell Carcinoma or Transitional Cell Carcinoma From the ANZDATA Database.

OBJECTIVES: Our objective was to determine the incidence and outcomes of renal cell carcinoma and transitional cell carcinoma in recipients of renal allografts. MATERIALS AND METHODS: We analyzed data from 2000 to 2012 in the Australia and New Zealand Dialysis and Transplant Registry, a binational population-based database, to identify the incidence and survival outcomes of renal transplant recipients with renal cell and transitional cell carcinoma. RESULTS: Of the 8850 renal transplants, there were 60 new diagnoses of renal cancers posttransplant, with an overall cumulative incidence of 56 per 100,000 per year. Nine tumors were detected in the allograft, and 51 tumors (85%) were detected in the native kidney of the recipient. The median time of diagnosis from transplant was 6.6 years (range, 0.1-8.9 y). There were no cancer-specific deaths from allograft tumors; however, 17 cancer-specific deaths (14 from renal cell carcinoma and 3 from transitional cell carcinoma) occurred in patients with cancer in the native kidney. The 5-year and 10-year cancer-specific survival rates for renal cell carcinoma were 71.2% (95% confidence interval (CI): 57.0-84.0) and 58.5% (95% CI: 40.5-77.9), with 5-year and 10-year rates for transitional cell carcinoma of 50% (95% CI: 15.5-94.2) and 0%. CONCLUSIONS: Renal cell carcinoma occurring in the native kidney comprised most of the tumors detected after renal transplant; however, transitional cell carcinoma occurred sooner after transplant and resulted in a lower cancer-specific survival rate. While it is important to screen those at risk of TCC prior and after renal transplant, the low incidence of TCC maybe too small to justify a benefit with routine screening, compared to RCCs.

Waiting for definitive care: An analysis of elapsed time from decision to surgery or transfer in a rural centre.

OBJECTIVE: To examine the timing of operative management and interhospital transfer of emergency general surgical patients in a regional setting. DESIGN: Retrospective cohort study. SETTING: The surgical unit at a major rural referral centre for North-Eastern Victoria servicing a population of 90 000. PARTICIPANTS: General surgical patients (n = 649) admitted via the emergency department at Northeast Health Wangaratta between January 2011 and March 2013 undergoing operative management (n = 608) or transfer to a tertiary centre (n = 44). MAIN OUTCOME MEASURES: Timing of operative management, using appendicectomy as a benchmark operation, was measured as time from presentation to decision to operate, time from decision to surgery, percentage after-hours operating and length of stay (LOS). Time to interhospital transfer was calculated and reasons for delay were sought. RESULTS: Two hundred forty-six appendicectomies were performed. Median time from decision to operate to theatre was 3 hours (interquartile range (IQR) 2-8), and total LOS was 43 hours (IQR: 28-56). Two hundred seventy-two procedures (43%) were performed out-of-hours, including 48% of appendicectomies. Median time from decision making to transfer was 10.3 hours (IQR: 4.7-25). Transfer was less likely to be delayed in trauma patients when compared with urgent non-trauma patients (5.3 versus 10.6 hours; P = 0.04). CONCLUSION: Even in the absence of a strict four-hour rule program and a dedicated emergency surgical unit, main outcome measures appear to be comparatively efficient. However, the duration for transfer of patients is suboptimal because of the lack of established pathways for urgent non-trauma transfer from rural centres and bed availability in tertiary hospitals.

HIF1α expression under normoxia in prostate cancer--which pathways to target?

PURPOSE: HIF1α over expression correlates with poor prognosis in a number of cancers. Although it is widely accepted that hypoxia induces HIF1α expression up-regulation by a reduction in oxygen dependent degradation, HIF1α up-regulation under normoxic conditions is noted with increasing frequency in many cancers. We reviewed the current knowledge of mechanisms of normoxic and hypoxic HIF1α up-regulation, and its therapeutic implications with a particular focus on its role as a potential biomarker in prostate cancer. MATERIALS AND METHODS: Although the literature on the role of HIFs in cancer development and progression has been reviewed extensively, few publications have specifically considered the role of HIFs in prostate cancer. Therefore, we searched PubMed® and Google® with the key words prostate cancer, castration resistance, metastasis, hypoxia, HIF1α, HIF2α and regulation. Relevant articles, including original research studies and reviews, were selected based on contents and a synopsis was generated. RESULTS: Normoxic expression of HIF1α has an important role in the development of prostate cancer chemoresistance, radioresistance and castrate resistance. Thus, HIF1α could serve as a potential biomarker. Furthermore, agents that target HIF1α could be used as adjuvant therapy to decrease resistance to conventional treatment modalities. HIF1α over expression in prostate cancer can be regulated at 3 levels, including transcription, translation and protein stability, by a number of mechanisms such as gene amplification, single nucleotide polymorphism, increased transcription of HIF1α mRNA, expression of truncated isoforms of HIF1α and stabilization of HIF1α. However, there is no definitive consensus and the intriguing question of how HIF1α is up-regulated in prostate cancer is still unanswered. CONCLUSIONS: HIF1α over expression under normoxia could serve as a biomarker for chemoresistance, radioresistance and castrate resistance in prostate cancer. There is an urgent need to identify the cause of HIF1α over expression in castrate resistant prostate cancer cells and tumors to guide the choice of HIF inhibitors (transcription or translation based) that are best suited for treating castrate resistant prostate cancer.

Perceptions of radiation oncologists and urologists on sources and type of evidence to inform prostate cancer treatment decisions.

PURPOSE: To perform a national survey of radiation oncologists and urologists about the type of resources used and the level of evidence needed to change clinical practice in localized prostate cancer. METHODS AND MATERIALS: From a random sample, 1422 physicians were mailed a survey assessing the types of information used and what level of evidence could alter their clinical practice in prostate cancer. Multivariable logistic regression models were used to identify differences in physician characteristics for each outcome. RESULTS: Survey response rates were similar for radiation oncologists and urologists (44% vs 46%; P=.46). Specialty-specific journals represented the most commonly used resource for informing the clinical practice for radiation oncologists (65%) and urologists (70%). Relative to radiation oncologists, urologists were less likely to report utilizing top-tier medical journals (25% vs 39%; adjusted odds ratio [OR] 0.50; P=.01) or cancer journals (22% vs 51%; adjusted OR 0.50; P<.001) but more likely to rely on clinical guidelines (46% vs 38%; adjusted OR 1.6; P=.006). Both radiation oncologists and urologists most commonly reported large randomized, clinical trials as the level of evidence to change treatment recommendations for localized prostate cancer (85% vs 77%; P=.009). CONCLUSIONS: Both specialties rely on their own specialty-specific journals and view randomized, clinical trials as the level of evidence needed to change clinical practice. Our study provides a context on meaningful ways of disseminating evidence for localized prostate cancer.

The effects of nonspecific HIF1α inhibitors on development of castrate resistance and metastases in prostate cancer.

Expression of hypoxia-inducible factor (HIF)1α increases the risk of castrate-resistant prostate cancer (CRPC) and metastases in patients on androgen deprivation therapy (ADT) for prostate cancer (PC). We aimed to investigate the effects of nonspecific HIF1α inhibitors (Digoxin, metformin, and angiotensin-2 receptor blockers) on development of CRPC and metastases while on ADT. A retrospective review of prospectively collected medical records was conducted of all men who had continuous ADT as first-line therapy for CRPC at the Austin Hospital from 1983 to 2011. Association between HIF1α inhibitor medications and time to develop CRPC was investigated using actuarial statistics. Ninety-eight patients meeting the criteria were identified. Eighteen patients (21.4%) were treated with the nonspecific HIF1α inhibitors. Both groups had similar characteristics, apart from patients on HIF1α inhibitors being older (70 years vs. 63.9 years). The median CRPC-free survival was longer in men using HIF1α inhibitors compared to those not on inhibitors (6.7 years vs. 2.7 years, P = 0.01) and there was a 71% reduction in the risk of developing CRPC (HR 0.29 [95% CI 0.10-0.78] P = 0.02) after adjustment for Gleason score, age, and prostate-specific antigen (PSA). The median metastasis-free survival in men on HIF1α inhibitors was also significantly longer compared to those on no inhibitors (5.1 years vs. 2.6 years, P = 0.01) with an 81% reduction in the risk of developing metastases (HR 0.19 [CI 0.05-0.76] P = 0.02) after adjustment for Gleason score, age, and PSA. Nonspecific HIF1α inhibitors appear to increase the progression-free survival and reduce the risk of developing CRPC and metastases in patients on continuous ADT.

Population-based analysis of prostate-specific antigen (PSA) screening in younger men (<55 years) in Australia.

OBJECTIVE: To analyse the trends in opportunistic PSA screening in Australia, focusing on younger men (<55 years of age), to examine the effects of this screening on transrectal ultrasonography (TRUS)-guided biopsy rates and to determine the nature of prostate cancers (PCas) being detected. SUBJECTS AND METHODS: All men who received an opportunistic screening PSA test and TRUS-guided biopsy between 2001 and 2008 in Australia were analysed using data from the Australian Cancer registry (Australian Institute of Health and Welfare) and Medicare databases. The Victorian cancer registry was used to obtain Gleason scores. Age-standardized and age-specific rates were calculated, along with the incidence of PCa, and correlated with Gleason scores. RESULTS: A total 5 174 031 PSA tests detected 128 167 PCas in the period 2001-2008. During this period, PSA testing increased by 146% (a mean of 4629 tests per 100 000 men annually), with 80 and 59% increases in the rates of TRUS-guided biopsy and incidence of PCa, respectively. The highest increases in PSA screening occurred in men <55 years old and up to 1101 men had to be screened to detect one incident case of PCa (0.01%). Screening resulted in two thirds of men aged <55 years receiving a negative TRUS biopsy. There was no correlation with Gleason >7 tumours in patients aged <55 years. CONCLUSION: Despite the ongoing controversy about the merits of PCa screening, there was an increase in PSA testing, especially in men <55 years old, leading to a modestly higher incidence of PCa in Australia. Overall, PSA screening was associated with high rates of negative TRUS-biopsy and the detection of low/intermediate grade PCa among younger patients.

Torsion of Wandering Gallbladder following Colonoscopy.

Torsion of the gallbladder is an uncommon condition that may present as an acute abdomen. Its preoperative diagnosis can often be challenging due to its variable presentation, with specific sonographic signs seen infrequently. We describe, to our knowledge, the first case of torsion of a wandering gallbladder following a colonoscopy in a 69-year-old female who presented with acute abdominal pain after procedure. This was discovered intraoperatively, and after a subsequent cholecystectomy, she had an uncomplicated recovery.

Bladder carcinoma in situ (CIS) in Australia: a rising incidence for an under-reported malignancy.

OBJECTIVES: To investigate the incidence of carcinoma in situ (CIS) in Australia and examine implications for its diagnosis and management, as CIS of the urinary bladder is a non-reportable disease in Australia. METHODS: Analysis of annual hospitalisation data using Australian Institute of Health and Welfare (AIHW) datasets showed an increase in CIS from 2001 onwards. To determine whether the increase seen with AIHW data represented a true increase in the rates offices, patient level data was examined using the Centre for Health record linkage (CHeReL) datasets. RESULTS: CHeReL linked data of 13,790 males and 5902 females, calculated the average incidence of CIS to be 20.9 per 100,000 and 6.5 per 100,000 respectively in those aged > 50 years, showing a rapid increase in the rates of CIS from 2001. There was an 11% (P = 0.04) and 14% (P = 0.02) annual increase in incidence of CIS in men and women and these rates increased with age. CONCLUSIONS: National data (AIHW) substantially underestimate the incidence of CIS in the Australian population. Patient level data suggest CIS rates are rapidly increasing in Australia despite high treatment rates. Closer surveillance and awareness of these high rates warrants further study and we recommend that CIS be considered a reportable disease.

The role of hypoxia-inducible factor 1α in determining the properties of castrate-resistant prostate cancers.

BACKGROUND: Castrate-resistant prostate cancer (CRPC) is a lethal condition in patients receiving androgen deprivation therapy for prostate cancer (PC). Despite numerous studies showing the expression of HIF1α protein under normoxia in PC cell lines, the role of this normoxic HIF1α expression in chemo-resistance and migration has not been investigated previously. As no method is currently available to determine which tumors will progress to CRPC, the role of HIF1α in PC and its potential for predicting the development of CRPC was also investigated. METHODS: The effect of HIF1α protein knockdown on chemo-resistance and migration of PC3 cells was assessed by cell counting and Transwell assays, respectively. Translation efficiency of HIF1α mRNA was determined in PC cells using a HIF1α 5'UTR-luciferase construct. Clinical outcomes were correlated following the staining of 100 prostate tumors for HIF1α expression. RESULTS: The CRPC-like cell lines (PC3 and DU145) expressed more HIF1α protein than an androgen sensitive cell line (LNCaP). Migration rate and chemo-resistance were higher in the PC3 cells and both were decreased when HIF1α expression was reduced. Increased translation of HIF1α mRNA may be responsible for HIF1α overexpression in PC3 cells. Patients whose tumors expressed HIF1α had significantly decreased metastasis-free survival and the patients who were on androgen-deprivation therapy had decreased CRPC-free survival on Kaplan-Meier analysis. On multivariate analysis HIF1α was an independent risk factor for progression to metastatic PC (Hazard ratio (HR) 9.8, p = 0.017) and development of CRPC (HR 10.0, p = 0.021) in patients on androgen-deprivation therapy. Notably the tumors which did not express HIF1α did not metastasize or develop CRPC. CONCLUSIONS: HIF1α is likely to contribute to metastasis and chemo-resistance of CRPC and targeted reduction of HIF1α may increase the responsiveness of CRPCs to chemotherapy. Expression of HIF1α may be a useful screening tool for development of CRPC.