Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set

BACKGROUND

A multi-cancer early detection (MCED) test used to complement existing screening could increase the number of cancers detected through population screening, potentially improving clinical outcomes. The Circulating Cell-free Genome Atlas study (CCGA; NCT02889978) was a prospective, case-controlled, observational study and demonstrated that a blood-based MCED test utilizing cell-free DNA (cfDNA) sequencing in combination with machine learning could detect cancer signals across multiple cancer types and predict cancer signal origin (CSO) with high accuracy. The objective of this third and final CCGA substudy was to validate an MCED test version further refined for use as a screening tool.

PATIENTS AND METHODS

This pre-specified substudy included 4077 participants in an independent validation set (cancer: n = 2823; non-cancer: n = 1254, non-cancer status confirmed at year-one follow-up). Specificity, sensitivity, and CSO prediction accuracy were measured.

RESULTS

Specificity for cancer signal detection was 99.5% [95% confidence interval (CI): 99.0% to 99.8%]. Overall sensitivity for cancer signal detection was 51.5% (49.6% to 53.3%); sensitivity increased with stage [stage I: 16.8% (14.5% to 19.5%), stage II: 40.4% (36.8% to 44.1%), stage III: 77.0% (73.4% to 80.3%), stage IV: 90.1% (87.5% to 92.2%)]. Stage I-III sensitivity was 67.6% (64.4% to 70.6%) in 12 pre-specified cancers that account for approximately two-thirds of annual USA cancer deaths and was 40.7% (38.7% to 42.9%) in all cancers. Cancer signals were detected across >50 cancer types. Overall accuracy of CSO prediction in true positives was 88.7% (87.0% to 90.2%).

CONCLUSION

In this pre-specified, large-scale, clinical validation substudy, the MCED test demonstrated high specificity and accuracy of CSO prediction and detected cancer signals across a wide diversity of cancers. These results support the feasibility of this blood-based MCED test as a complement to existing single-cancer screening tests.

CLINICAL TRIAL NUMBER

NCT02889978.

Sensitive and specific multi-cancer detection and localization using methylation signatures in cell-free DNA

BACKGROUND

Early cancer detection could identify tumors at a time when outcomes are superior and treatment is less morbid. This prospective case-control sub-study (from NCT02889978 and NCT03085888) assessed the performance of targeted methylation analysis of circulating cell-free DNA (cfDNA) to detect and localize multiple cancer types across all stages at high specificity.

PARTICIPANTS AND METHODS

The 6689 participants [2482 cancer (>50 cancer types), 4207 non-cancer] were divided into training and validation sets. Plasma cfDNA underwent bisulfite sequencing targeting a panel of >100 000 informative methylation regions. A classifier was developed and validated for cancer detection and tissue of origin (TOO) localization.

RESULTS

Performance was consistent in training and validation sets. In validation, specificity was 99.3% [95% confidence interval (CI): 98.3% to 99.8%; 0.7% false-positive rate (FPR)]. Stage I-III sensitivity was 67.3% (CI: 60.7% to 73.3%) in a pre-specified set of 12 cancer types (anus, bladder, colon/rectum, esophagus, head and neck, liver/bile-duct, lung, lymphoma, ovary, pancreas, plasma cell neoplasm, stomach), which account for ∼63% of US cancer deaths annually, and was 43.9% (CI: 39.4% to 48.5%) in all cancer types. Detection increased with increasing stage: in the pre-specified cancer types sensitivity was 39% (CI: 27% to 52%) in stage I, 69% (CI: 56% to 80%) in stage II, 83% (CI: 75% to 90%) in stage III, and 92% (CI: 86% to 96%) in stage IV. In all cancer types sensitivity was 18% (CI: 13% to 25%) in stage I, 43% (CI: 35% to 51%) in stage II, 81% (CI: 73% to 87%) in stage III, and 93% (CI: 87% to 96%) in stage IV. TOO was predicted in 96% of samples with cancer-like signal; of those, the TOO localization was accurate in 93%.

CONCLUSIONS

cfDNA sequencing leveraging informative methylation patterns detected more than 50 cancer types across stages. Considering the potential value of early detection in deadly malignancies, further evaluation of this test is justified in prospective population-level studies.

Deep androgen receptor suppression in prostate cancer exploits sexually dimorphic renal expression for systemic glucocorticoid exposure

BACKGROUND

Enzalutamide and apalutamide are potent next-generation androgen receptor (AR) antagonists used in metastatic and non-metastatic prostate cancer. Metabolic, hormonal and immunologic effects of deep AR suppression are unknown. We hypothesized that enzalutamide and apalutamide suppress 11β-hydroxysteroid dehydrogenase-2 (11β-HSD2), which normally converts cortisol to cortisone, leading to elevated cortisol concentrations, increased ratio of active to inactive glucocorticoids and possibly suboptimal response to immunotherapy. On-treatment glucocorticoid changes might serve as an indicator of active glucocorticoid exposure and resultant adverse consequences.

PATIENTS AND METHODS

Human kidney tissues were stained for AR and 11β-HSD2 expression. Patients in three trials [neoadjuvant apalutamide plus leuprolide, enzalutamide ± PROSTVAC (recombinant poxvirus prostate-specific antigen vaccine) for metastatic castration-resistant prostate cancer (CRPC) and enzalutamide ± PROSTVAC for non-metastatic castration-sensitive prostate cancer] were analyzed for cortisol and its metabolites using liquid chromatography-mass spectrometry (LC-MS/MS). Progression-free survival was determined in the metastatic CRPC study of enzalutamide ± PROSTVAC for those with glucocorticoid changes above and below the median.

RESULTS

Concurrent AR and 11β-HSD2 expression occurs only in the kidneys of men. A statistically significant rise in cortisol concentration, cortisol/cortisone ratio and tetrahydrocortisol/tetrahydrocortisone ratio with AR antagonist treatment occurred uniformly across all three trials. In the trial of enzalutamide ± PROSTVAC for metastatic CRPC, high cortisol/cortisone ratio in the enzalutamide arm was associated with significantly improved progression-free survival. However, in the enzalutamide + PROSTVAC arm, the opposite trend was observed.

CONCLUSION

Enzalutamide and apalutamide treatment toggles renal 11β-HSD2 and significantly increases indicators of and exposure to biologically active glucocorticoids, which is associated with clinical outcomes.

Novel biomarkers and genomic tests in prostate cancer: a critical analysis

The aim of this review is to critically analyze the current state of research in selected biomarkers and genomic-based tests for prostate cancer (PCa) diagnosis, staging, prognostication, and monitoring. Although in Western societies, PCa is the most common solid malignancy and the second leading cause of cancer death in men, the vast majority of men with PCa are diagnosed with clinically localized disease. The widespread use of prostate-specific antigen (PSA) testing, on one hand, has resulted in earlier PCa detection at a potentially more curable stage, but on the other hand has led to an increase in the rate of negative biopsies, as well as overdetection and overtreatment of potentially indolent tumors that would not have become life-threatening to a patient. A multitude of molecular tests and algorithms has been developed to enhance diagnostic accuracy, improve pretreatment and post-treatment patient risk stratification, and identify aggressive versus indolent disease to facilitate therapeutic decision-making. PSA and derivatives (PSA kinetics, PSA density, percentage of free PSA) as well as algorithms based on PSA and PSA isoforms measurements (prostate health index, four-kallikrein score), urinary molecular biomarkers-based tests (Prostate Cancer Antigen 3, and the Michigan Health System Prostate Score) and selected genomic/proteomic tests now commercially available for disease prognostication (such as Confirm MDx, Prostate Core Mitomic Test, Oncotype DX, Prolaris, ProMark, and Decipher) are herein discussed to inform the readers about current and future clinical applications and their limitations. Finally, we briefly touch upon potential biomarkers predictive of response to therapy, such as androgen receptor splice variant AR-V7, and detection and quantification of circulating tumor cells in the blood stream.

A randomized controlled Alzheimer's disease prevention trial's evolution into an exposure trial: the PREADViSE Trial

OBJECTIVES

To summarize the ongoing prevention of Alzheimer's disease (AD) by vitamin E and selenium (PREADViSE) trial as an ancillary study to SELECT (a large prostate cancer prevention trial) and to present the blinded results of the first year as an exposure study.

DESIGN

PREADViSE was designed as a double blind randomized controlled trial (RCT).

SETTING

SELECT terminated after median of 5.5 years of exposure to supplements due to a futility analysis. Both trials then converted into an exposure study.

PARTICIPANTS

In the randomized component PREADViSE enrolled 7,547 men age 62 or older (60 if African American). Once the trial terminated 4,246 of these men volunteered for the exposure study. Demographics were similar for both groups with exposure volunteers having baseline mean age 67.3 ± 5.2 years, 15.3 ± 2.4 years of education, 9.8% African Americans, and 22.0% reporting a family history of dementia.

INTERVENTION

In the RCT men were randomly assigned to either daily doses of 400 IU of vitamin E or placebo and 200 µg of selenium or placebo using a 2x2 factorial structure.

MEASUREMENTS

In the RCT, participants completed the memory impairment screen (MIS), and if they failed, underwent a longer screening (based on an expanded Consortium to Establish a Registry in AD [CERAD] battery). CERAD failure resulted in visits to their clinician for medical examination with records of these examinations forwarded to the PREADViSE center for further review. In the exposure study, men are contacted by telephone and complete the telephone version of the memory impairment screen (MIS-T) screen. If they fail the MIS-T, a modified telephone interview of cognitive status (TICS-M) exam is given. A failed TICS-M exam also leads to a visit to their clinician for an in-depth examination and forwarding of records for a centralized consensus diagnosis by expert clinicians. A subgroup of the men who pass the MIS-T also take the TICS-M exam for validation purposes.

RESULTS

While this ancillary trial was open to all 427 SELECT clinical sites, only 130 (30.0%) of the sites chose to participate in PREADViSE. Staff turnover at the sites presented challenges when training persons unfamiliar with cognitive testing procedures to conduct the memory screens. In the RCT few participants (1.6%) failed the MIS screen and among those who passed this screen a significant practice effect was encountered. In the exposure study 3,581 men were reached by phone in year 1, 15.7% could not be reached after 5 calls, and of those contacted 6.0% refused the screen even after consenting to the procedures at their clinical site. Most notable is that the failure rate for the MIS-T increased fourfold to 7.2%. Of the 257 men who took the TICS-M, 84.0% failed and were asked to contact their physicians for a more detailed memory assessment, and approximately half of these had some form of dementia or cognitive impairment. Several of these dementia cases are not AD.

CONCLUSION

Partnering with SELECT led to an AD prevention trial conducted at a very reasonable cost by taking advantage of the experience and efficient clinical trial management found in a cancer cooperative group (Southwest Oncology Group or SWOG). Once unblinded, the RCT and exposure study data have the potential to yield new information on long term exposure to antioxidant supplements under controlled conditions.

Use of quantitative gene expression in primary and highest Gleason pattern cancers to identify genes associated with clinical recurrence after radical prostatectomy

39

Background: Prostate biopsy may not adequately sample small, secondary or tertiary Gleason pattern tumors which can drive clinical outcome. We conducted a study to determine whether tumor-derived gene expression profiling could identify a distinct underlying biology associated with clinical recurrence (cR) after radical prostatectomy (RP) across both the primary and highest Gleason pattern (GP) samples.

Methods: All patients (pts) with clinical stage T1/T2 prostate cancer treated with RP at Cleveland Clinic from 1987 to 2004 were identified (n∼f2,600). A cohort sampling design was used to select 127 patients with cR and 374 patients without cR after RP. Each patient had two spatially distinct tumor specimens sampled that included the primary GP and the highest GP. Surgical GS and clinical data were centrally reviewed. RNA was extracted from 6 manually dissected 10 μ m fixed paraffin embedded tissue sections obtained from the RP tumor specimens and expression of 732 cancer-related and reference genes was quantified using RT-PCR. Clinical recurrence-free interval (cRFI) was analyzed using Cox PH regression.

Results: Blocks from 441 patients were evaluable. Median F/U was 5.8 years. Pts were mostly Caucasian (83%), clinical stage T1 (66%), had baseline PSA <10 ng/mL (82%), and had surgical GS ≤7 (87%). As expected, surgical GP, biopsy GP, path T- stage, clin T-stage, baseline PSA, and year of surgery (p<0.05, unadj) were associated with cRFI. In the primary and highest GP specimens respectively, 295 and 297 genes were significantly associated (unadj. p<0.05) with cRFI. 235 genes were associated with cRFI in both specimens, well in excess of the number expected by chance. In a multivariate model adjusted for AUA risk group and allowing a 10% false discovery rate, 289 genes remained significantly and strongly associated with cRFI.

Conclusions: Gene expression analysis using quantitative RT-PCR identified a large number of genes, and underlying biology, that are strongly associated with clinical recurrence in both the primary and highest GP. This information can be used to develop a biopsy-based assay that distinguishes indolent versus aggressive disease.

[Table: see text]

Use of TMPRSS2-ERG gene rearrangement and quantitative ERG expression to predict clinical recurrence after radical prostatectomy

36

Background: The association of TMPRSS2-ERG fusions and ERG expression in prostate cancer (PC) with adverse clinical outcomes has been controversial, with mixed results in the literature. We conducted a study to test whether tumor-derived gene expression profiles, including the presence of TMPRSS2-ERG fusions and ERG gene expression, are associated with clinical recurrence (cR) after radical prostatectomy (RP).

Methods: All patients with clinical stage T1/T2 prostate cancer treated with RP at CC from 1987 to 2004 were identified (n∼f2,600). A cohort sampling design was used to select 127 patients with cR and 374 patients without cR after RP. For each patient a primary Gleason pattern (GP) sample, secondary (or highest) GP sample, and an adjacent nontumor tissue sample were evaluated. Surgical Gleason Score (GS) and clinical data were centrally reviewed. RNA was extracted from 6 manually dissected 10 μ m formalin-fixed paraffin-embedded sections obtained from RP specimens and expression of TMPRSS2-ERGa, TMPRSS2-ERGb, ERG and reference genes were quantified using RT-PCR. Times to cR, PSA recurrence, and PC death were analyzed using Cox PH regression.

Results: Blocks from 441 patients were evaluable. Median F/U was 5.8 years. Patients were mostly Caucasian (83%), clinical stage T1 (66%), had baseline PSA <10 ng/mL (82%), and had surgical Gleason score ≤7 (87%). 848 tumor samples and 410 non-tumor samples were assessed. TMPRSS2-ERGa and/or TMPRSS2-ERGb fusions were present in 51.8% of tumor samples and 7.5% of non-tumor samples. There was 89% concordance (95% CI: 86%, 92%) for TMPRSS2-ERG fusion status between the 2 tumor samples for each patient. High ERG expression was strongly associated with the presence of TMPRSS2-ERG fusions (p <0.01). We did not find an association between TMPRSS2-ERG a/b gene rearrangement or ERG expression with cR, PSA recurrence, PC death, or surgical GS (p > 0.2).

Conclusions: This study was notable for the large number of cR events, use of a standardized quantitative assay, and rigorous central review of pathology and clinical data. We did not find an association of TMPRSS2-ERG gene rearrangements or ERG expression with aggressiveness of prostate cancer post RP.

[Table: see text]

The impact of screening for prostate cancer on the development of metastatic disease

192

Background: Routine screening for prostate cancer (CaP) was first advocated in 1993 in the US. Opponents of screening argue that the implementation of routine screening has not resulted in a meaningful improvement in survival. Since we are essentially unable to cure metastatic disease, the best measure of the efficacy of screening may not be overall survival but instead its ability to lessen the metastatic disease burden of the screened population. We assess the effect of screening on this endpoint.

Methods: From 1986-1996, 1,721 patients with CaP were definitively treated with radical prostatectomy (RP) or radiotherapy (RT) at our institution. The cohort was divided into a pre screening era group (1986-1992; PRE, n=575) and a post screening era group (1993-1996; POST, n=1,146). Due to the potential for an imbalance in follow up time between the two groups, all patients were censored at ten years. Kaplan- Meier analysis was used to calculate the ten year metastases free survival rates (MFSR). Cox proportional hazards regression was used to examine if screening era along with disease, treatment, and follow-up characteristics was associated with an increased risk of developing metastatic disease.

Results: The median follow up for all patients was 10 yrs (range: 0.1-10), 9.6 yrs (range: 0.1-10) for PRE patients, and 10 yrs (range: 0.1-10) for POST patients. The distribution by NCCN risk classification for the PRE patients was 44% high risk (H), 21% intermediate risk (I) and 28% low risk (L) vs. 36% H, 27% I, and 37% L for the POST patients (p < 0.0001). Within 10 years of treatment, 13% of all patients had developed metastatic disease. The 10 year MFSR for high risk PRE vs POST patients was 58% vs. 82% (p < 0.0001), 79% vs. 93% for I (p < 0.0001), and 90% vs. 98% (p = 0.0001) for L patients. On multivariable analysis, screening era (p < 0.0001, HR = 4.6, 95% CI = 3.4-6.1), T-stage, biopsy Gleason score, and post-treatment PSA testing frequency were significant.

Conclusions: Screening for CaP results in a significant decrease in the risk of a patient developing metastatic disease within 10 years of treatment even after controlling for severity of disease. This risk reduction may yield improved quality of life and a cost savings to the medical care system.

No significant financial relationships to disclose.

Correlation of percent of core biopsies positive for prostate cancer and biochemical outcome following I-125 prostate brachytherapy or external beam radiation

40

Background: The percentage of positive cores (PPC) on biopsy for prostate cancer has been identified as a predictor of outcome following definitive local treatment. We aim to identify whether this observation holds true for a modern cohort of patients (pts) treated at Cleveland Clinic with permanent prostate brachytherapy (PB) or external beam radiation therapy (EBRT).

Methods: We retrospectively reviewed pathology reports of pts treated with either PB or EBRT from our IRB-approved prospective prostate cancer registry. No pts underwent both PB and EBRT. The number of biopsy cores sampled, number of cores positive for prostate cancer, and maximum length of any core positive for prostate cancer were collected. Cox proportional hazards regression was used to analyze biochemical relapse free survival (bRFS) using the nadir + 2 ng/ml definition.

Results: We identified 1253 PB and 879 EBRT pts with complete pathology and clinical information. Among PB pts, 46% were low risk, 40% intermediate risk, and 14% high risk, while 78% had <50% PPC, and 22% had >=50% PPC. The 5-year bRFS for PB was 92.0% for <50% PPC, vs. 83.1% for >=50% PPC (HR 2.1, p=0.0005). For PB pts, significant predictors of bRFS on univariate analysis included: PPC, clinical T stage, PSA, biopsy Gleason score, androgen deprivation, and frequency of PSA testing. On multivariate analysis, only PPC, biopsy Gleason score, and PSA frequency remained significant predictors following PB. Among EBRT pts, 11% were low risk, 36% intermediate risk, and 53% high risk, while 55% had <50% PPC, and 45% had >=50% PPC. The 5-year bRFS for EBRT was 85.6% for <50% PPC, vs. 77.1% for >=50% PPC (HR 1.8, p<0.0001). For EBRT pts, significant predictors of bRFS on univariate analysis included: PPC, clinical T stage, PSA, biopsy Gleason score, androgen deprivation, EBRT dose, and frequency of PSA testing. On multivariate analysis, only PPC, biopsy Gleason score, and PSA frequency remained significant predictors following EBRT.

Conclusions: Following PB or EBRT, the percent of positive cores for prostate cancer was a significant predictor of bRFS on multivariate analysis, more so than conventional predictors such as T stage and PSA.

No significant financial relationships to disclose.

Clinical recurrence post-biochemical failure of prostate cancer

195

Background: The purpose of this study is to evaluate the role of salvage therapy (STx) after biochemical failure (bF) for prostate cancer (CaP) and to determine what factors are associated with the development of clinical recurrence (cR).

Methods: From 1996-2009, 7,585 patients (pts) with CaP were treated with prostatectomy (RP), brachytherapy (PI), or external beam radiotherapy (RT). For RP patients (pts), bF was defined as a postoperative PSA >0.3 and for PI and RT pts the Phoenix definition was used. bF was documented in 927 pts. cR was defined as any image-based or pathological diagnosis of disease recurrence after bF. Cox proportional hazards regression was used to examine if the use of STx after bF, the time of bF, along with disease characteristics were associated with cR after bF.

Results: The median follow-up after bF was 31months (mo; range: 0-131). Thirty percent of pts had a cR after bF, and the 5-year rate of cR free survival was 58%. STx within 1 year after bF (early) was given to 46% of pts, STx more than 1 year after bF (late) was given to 11% of pts, and 43% of pts did not receive STx. On univariate analysis, factors found to be significantly associated (p-value <0.05) with cR were a short interval between initial treatment and bF (bFTime), no use of STx, early initiation of STx, biopsy Gleason Score (bGS), clinical stage, older age at bF, the use of PI or RT, and increased frequency of PSA follow-up after bF (PSAfreq). In multivariable analysis, bFTime, no use of STx, early initiation of STx, bGS, the use of PI or RT, and PSAfreq remained significant. To better evaluate the effect the timing of initiation of STx had on the development of cR, a second analysis was preformed, limited to the 529 pts who did receive STx after bF. In multivariable analysis, early use of STx remained significant for cR (HR=2.09, 95%CI=1.24- 3.51). As a continuous variable, in a second multivariable analysis, delayed use of STx resulted in a reduced risk of developing cR (HR=0.98, 95%CI=0.96-1.00).

Conclusions: This study suggests that while the use of STx after bF reduces the risk of subsequently developing cR, early use of STx after bF is not beneficial. Other factors such as the time interval between initial treatment and bF need to be evaluated when determining when to initiate STx after bF.

No significant financial relationships to disclose.

Brachytherapy as salvage treatment for local nodular recurrence of prostate cancer

86

Background: Men diagnosed with adenocarcinoma of the prostate treated with radical prostatectomy (RP) have a 10% risk of developing local recurrence within 10 years. While the majority of these recurrences are biochemical failures with no foci of disease, we report on a series of 7 patients who had nodular recurrences in the post-surgical bed and subsequently underwent low-dose rate (LDR) brachytherapy as salvage therapy.

Methods: Patients who were initially treated with RP and subsequently with salvage LDR I-125 brachytherapy for a nodular recurrence were included in this series. All patients failed biochemically within 10 years of RP and received no other adjuvant or salvage treatment by choice. Nodular recurrences were biopsy confirmed adenocarcinoma, and patients had no evidence of nodal or distant metastasis on imaging or bone scan. All patients consented to salvage with LDR brachytherapy. Follow up post-salvage was at least every 6 months with a serial PSA.

Results: Seven patients underwent salvage LDR brachytherapy with median age of 74 (range 63-77) at time of salvage. The median pre-salvage PSA was 4.56. The biopsy Gleason score of the nodular recurrences was 7 or 8. Median volume of nodular recurrence was 16cc, median number of sources was 30, median D90 for nodule was 155.02 Gy, and median rectum V100 was 0.01. Compared to baseline prior to salvage, patients have reported no additional urinary symptoms or sexual side effects from salvage. Patients have been followed for a median of 28 months post-salvage (range 4-48 months) with a median PSA at last follow up of 1.05.

Conclusions: This report presents the first known case series of prostate cancer patients treated with RP who developed local nodular recurrences which were then treated with LDR brachytherapy. For patients who develop a nodular recurrence with no other evidence of distant metastases, LDR brachytherapy offers a novel salvage option.

No significant financial relationships to disclose.

Long-term (potential 10-year follow-up) toxicity after treatment for prostate cancer with either external beam radiation therapy, interstitial brachytherapy, or radical prostatectomy

65

Background: To examine gastrointestinal (GI) and genitourinary (GU) toxicity profiles of patients treated in 1999 with external beam radiotherapy (RT), prostate interstitial brachytherapy (PI) or radical prostatectomy (RP).

Methods: The records of 483 patients treated in 1999 were retrospectively reviewed to evaluate toxicity profiles, with 24% of the patients treated with PI, 40% with RP, and 36% with RT. Late GI and GU morbidity profiles were specifically examined and both were graded according to the RTOG acute and late morbidity scoring criteria. Other factors examined were patient age, BMI, smoking history, and medical comorbidities including presence of diabetes mellitus (DM), peripheral vascular disease, and connective tissue disease. Due to the low event rate for late GU and GI toxicities, a competing risk regression (CRR) analysis was done with death as the competing event.

Results: See Table. Median follow-up time was 8.6 years (range 0.2-11.5). On CRR univariate analysis the presence of DM was associated with GU toxicity grade ≥2 (p=0.043, HR 2.35, 95% CI=1.03-5.39). DM remained significant on multivariate analysis (p=0.034, HR 2.44, 95% CI= 1.07-5.59). Since there were no events in the RP group, only the PI and RT patients were included in the CRR analysis for late GI toxicity Grade <=2. On univariate analysis, RT and DM were significantly associated with late GI toxicity. On multivariable analysis, both variables remained significant (RT: p=0.038, HR=4.71, 95%CI=1.09-20.3; DM: p=0.008, HR=3.81, 95%CI=1.42-10.2).

Conclusions: Late effects occur with all three treatment modalities. The presence of DM at the time of treatment was significantly associated with worse late GI and GU toxicity. RT was significantly associated with worse late GI toxicity compared to PI and RP.

[Table: see text]

No significant financial relationships to disclose.

A simple indentation device for measuring micrometer-scale tissue stiffness

Mechanical properties of cells and extracellular matrices are critical determinants of function in contexts including oncogenic transformation, neuronal synapse formation, hepatic fibrosis and stem cell differentiation. The size and heterogeneity of biological specimens and the importance of measuring their mechanical properties under conditions that resemble their environments in vivo present a challenge for quantitative measurement. Centimeter-scale tissue samples can be measured by commercial instruments, whereas properties at the subcellular (nm) scale are accessible by atomic force microscopy, optical trapping, or magnetic bead microrheometry; however many tissues are heterogeneous on a length scale between micrometers and millimeters which is not accessible to most current instrumentation. The device described here combines two commercially available technologies, a micronewton resolution force probe and a micromanipulator for probing soft biological samples at sub-millimeter spatial resolution. Several applications of the device are described. These include the first measurement of the stiffness of an intact, isolated mouse glomerulus, quantification of the inner wall stiffness of healthy and diseased mouse aortas, and evaluation of the lateral heterogeneity in the stiffness of mouse mammary glands and rat livers with correlation of this heterogeneity with malignant or fibrotic pathology as evaluated by histology.

Predicting the long-term risk of prostate cancer-specific mortality after radical prostatectomy

5007

Background: Nomograms that predict prostate-specific antigen (PSA) defined biochemical recurrence (BCR) of prostate cancer after radical prostatectomy are the most widely used prediction tools in oncology for treatment decision making and counseling. While BCR universally antedates prostate cancer-specific mortality (PCSM), it is a limited surrogate endpoint due to its variable natural history. Nomograms that accurately predict the risk of PCSM are needed. Methods: Using Fine and Gray competing risk regression analysis, the clinical data and follow-up information of 11,521 patients treated with radical prostatectomy at four academic centers from 1987 to 2005 were modeled to predict PCSM. The model was externally validated on 12,893 patients treated at a separate institution during the same period. Results: The 15-year PCSM and all-cause mortality was 7% and 33%, respectively. The 15-year PCSM for patients with final pathological Gleason score 2–6, 3+4, 4+3, and 8–10 was 1%, 7%, 8%, and 49%, respectively. By pathologic stage, the risks were 2%, 7%, 29%, and 23% for organ-confined, extraprostatic extension, seminal vesicle invasion, and lymph node-positive prostate cancer. Of 3756 patients with organ-confined and Gleason 2–6 cancer, only 1 (0.03%) died from prostate cancer. Primary and secondary Gleason grade (p < 0.001 for both), seminal vesicle invasion (p < 0.001), and year of surgery (p = 0.002) were significant predictors of PCSM. A nomogram predicting 15-year PCSM based on pathologic parameters was accurate and discriminating with an externally-validated concordance index of 0.92. Conclusions: A nomogram has been constructed that predicts the long-term risk of PCSM after radical prostatectomy based on the pathologic grade and stage of the cancer. The presence of poorly differentiated cancer and seminal vesicle invasion are the prime determinants of PCSM. Our study suggests that biomarkers may have limited empiric prognostic utility as PCSM can be accurately predicted once the pathologic features of prostate cancer are known.

No significant financial relationships to disclose.

A comparison of overall and cause-specific survival among patients with low- and intermediate-risk prostate cancer treated with brachytherapy, external beam radiotherapy, or radical prostatectomy

5126

Background: The factors thought to influence overall survival (OS) and cause-specific survival (CSS) in patients treated for low and intermediate-risk prostate cancer (CaP) with brachytherapy (PI), external beam radiotherapy (RT), or radical prostatectomy (RP) were evaluated. Methods: From 1996 to 2003, 2285 patients with low or intermediate-risk CaP were treated at the Cleveland Clinic with either PI (n=662), RT (n=570), or RP (n=1053). Factors thought to influence OS and CSS were recorded. These factors included: Charlson score, age, socioeconomic status, race, body mass index (BMI), presence of coronary artery disease (CAD), presence of hypertension (HTN), presence of dyslipidemia (DL), initial prostate-specific antigen (iPSA), biopsy Gleason score (bGS), clinical stage, use of androgen deprivation (AD), AD duration, smoking history including pack-years, alcohol use, and cancer treatment modality (TX). Univariate and multivariate analyses were done using Cox proportional hazards regression. Results: The median follow-up is 59 months (range: 24–119 months). The 5- year OS rate is 96.0%, and the 8-year rate is 89.9%. Multivariate analysis revealed that Charlson score, age, smoking history, and TX were significantly associated with OS. Treatment with RT was independently associated with worse OS relative to PI and RP. CSS was grouped into 4 major categories: CAD, CaP, other cancer, and other. The only significant difference between these CSS categories and the treatment modalities was CaP. The percent of deaths due to CaP in the TX groups were: PI - 3.2%, RP - 9.7%, and RT - 24.5%. Conclusions: Charlson score, age, smoking history, and TX independently affect OS in patients treated for low and intermediate-risk CaP. The cause of the lower OS rate with RT may be related to an increased risk of death due to CaP.

[Table: see text]

No significant financial relationships to disclose.

Periprostatic local anesthesia eliminates pain of office-based transrectal prostate biopsy

Up to 96% of patient who undergo prostate biopsy report pain. We performed periprostatic local anesthesia injection in an effort to improve patient acceptance of prostate biopsy. Sixty patients were randomized to receive either local injection of lidocaine in the periprostatic nerves or no anesthetic. Lidocaine was injected through a 7-inch spinal needle placed through a transrectal ultrasound biopsy guide. Ten-core biopsies were immediately performed. Following biopsy, all patients gave a Visual Analog Scale (VAS) assessment of their pain experienced during biopsy.A majority of patients reported Visual Analog Scale (VAS) scores in the moderate (28.6%) or severe (28.6%) ranges unless local anesthesia was given. Only one of 27 patients (3.7%) receiving local anesthetic reported moderate pain, and none reported severe pain. Mean VAS pain scores were 1.4 in the anesthetic group and 4.5 in the control group (P<0.0001). No difficulty was encountered from scarring in the five patients who underwent nerve spring radical retropubic prostatectomy following local anesthetic injection. Periprostatic injection of local anesthetic essentially eliminates pain from prostate biopsy. Nerve-sparing radical retropubic prostatectomy is not more difficult as a result.

Phase II trial of GM-CSF in advanced prostate cancer

OBJECTIVES

Prostate-specific antigen only disease progression following definitive therapy is significant therapeutic dilemma. The benefit of hormonal therapy remains unproven and is associated with significant toxicity, more pronounced with chronic use. Biochemical progression following hormonal therapy has no standard treatment. New approaches to the management of this subset of patients are needed. A previous study in advanced prostate cancer demonstrated biologic activity of granulocyte macrophage-colony stimulating factor. The purpose of this study was to evaluate the activity of granulocyte macrophage-colony stimulating factor in a less heavily pretreated population.

MATERIALS AND METHODS

Sixteen patients with advanced prostate cancer, 7 hormonally naïve, and 9 androgen independent, were treated with granulocyte macrophage-colony stimulating factor administered subcutaneously at 250 microg three times a week for up to 6 months. Prostate-specific antigen measurements were obtained every 2 weeks.

RESULTS

No patient achieved an objective response. Six patients demonstrated a 10-15% decline in their baseline prostate-specific antigen which was maintained during the entire treatment period. Five of these 6 patients demonstrated a rise in their prostate-specific antigen following study completion. Therapy was well tolerated, with only 1 grade 3 event which was not treatment-related.

CONCLUSIONS

Granulocyte macrophage-colony stimulating factor demonstrates modest biologic evidence of activity in prostate cancer as manifested by prostate-specific antigen response. Further investigation of the mechanism of activity and additional clinical evaluation of this agent seems warranted.

Aneusomy of chromosomes 7, 8, and 17 and amplification of HER-2/neu and epidermal growth factor receptor in Gleason score 7 prostate carcinoma: a differential fluorescent in situ hybridization study of Gleason pattern 3 and 4 using tissue microarray

Recent evidence shows that the proportion of poorly differentiated prostate carcinoma (Gleason pattern [GP] 4/5) is a surrogate factor for biochemical failure after radical prostatectomy (RP). However, little is known about specific molecular and cytogenetic changes in this aggressive component of localized prostate cancer. We constructed a tissue microarray containing areas of GP 3 and 4 from formalin-fixed radical prostatectomy specimens of 39 patients with Gleason score 7 carcinoma (>or=50% GP 4), known pathologic staging parameters (stage < T3b), and biochemical failure data (mean follow-up, 30 months; range, 5 to 74 months). Interphase fluorescent in situ hybridization (FISH) was performed on 5-microm microarray sections using pericentromeric probes to chromosomes 7, 8, and 17 and probes for the HER-2/neu and epidermal growth factor receptor (EGFR) genes. Low-level amplification of HER-2/neu was found in 26% of cases (3 to 5 signals per nucleus, corrected for chromosome 17 aneusomy). Aneusomy of chromosomes 7, 8, and 17 was identified in 21%, 15%, and 5% of cases, respectively. All aberrations occurred almost exclusively in GP 4 carcinoma (8 of 8 aneusomies 7, 2 of 2 trisomies 17, 9 of 10 HER-2/neu amplifications, and 5 of 6 aneusomies 8; P < .001). The presence of HER-2/neu amplification was associated with high tumor volume (>2.0 cm(3), P = 0.004). Among patients with negative surgical margins, gain of chromosome 7 was associated with biochemical failure after RP (P =.004, log-rank). Amplification of the EGFR gene occurred in only 1 case (3%). Significant differences in HER-2/neu amplification and gain of chromosomes 7, 8, and 17 were detected between GP 4 prostate carcinoma and GP 3. The frequency of aberrations increased with tumor volume. Chromosome 7 abnormalities may play an important role in cancer progression in margin-negative patients. EGFR amplification was rare, suggesting that this oncogene is not altered at the gene copy number level.

Management of erectile dysfunction following radical prostatectomy

Radical prostatectomy is the standard treatment for organ/specimen-confined prostate cancer, yet erectile dysfunction in selected series is still reported as high as 90% after this procedure. Thus, most men need adjuvant treatments to be sexually active following radical prostatectomy. These include vacuum constriction devices, intracorporeal injections of vasoactive drugs, and transurethral dilators, all of which have reported response rates of 50% to 70%. Unfortunately, long-term compliance is suboptimal, with a discontinuation rate of nearly 50% at one year. These non-oral options should be offered on an individual basis to patients who have failed oral therapy since efficacy and compliance vary. Also, these options should be considered in the early postoperative period to enhance sexual activity and penile oxygenation, which may prevent corporeal fibrosis. Early penile rehabilitation with intracavernosal injections or vacuum constriction devices should be encouraged to increase chances for recovery of rigid erections. In patients with some preservation of nerve tissue, oral sildenafil may be effective in promoting an earlier return of erectile function. The potential impact of sildenafil and other new oral therapies should encourage urologists to continue to perform and perfect the nerve-sparing approach.