Intensification patterns and the probability of HbA1c goal attainment in Type 2 diabetes mellitus: real-world evidence for the concept of 'intensification inertia'.

AIMS: To assess the effects of 'clinical' and 'intensification inertia' by evaluating the impact of different intensification interventions on the probability of HbA1c goal attainment using real-world data. METHODS: Electronic health records (Cleveland Clinic, 2005-2016) were used to identify 7389 people with Type 2 diabetes mellitus and HbA1c ≥53 mmol/mol (≥7.0%), despite a stable regimen of two oral antihyperglycaemic drugs for ≥6 months. The participants were stratified by index HbA1c and analysed over a 6-month period for pharmacological intensification, and then for 12 additional months for HbA1c goal attainment (<53 mmol/mol). RESULTS: The probability of HbA1c goal attainment (Kaplan-Meier analysis) in the group with index HbA1c 53-63 mmol/mol (7.0-7.9%) was highest with the addition of oral antidiabetic drugs [57.3% (95% CI 52.1, 62.0)] or glucagon-like peptide-1 receptor agonists [56.7% (95% CI 40.4, 68.6)], in the 64-74 mmol/mol (8.0-8.9%) group with the addition of oral antidiabetic drugs [31.9% (95% CI 25.1, 38.1)] or insulin [30.6% (95% CI 18.3, 41.0)], and in the ≥75 mmol/mol (≥9.0%) group with the addition of glucagon-like peptide-1 receptor agonists [53.0% (95% CI 31.8, 67.6)] or insulin [43.5% (95% CI 36.4, 49.8)]. CONCLUSIONS: Numerical, but not statistically significant, differences in HbA1c goal attainment probability by type of intensification were most marked in people with the highest index HbA1c [≥75 mmol/mol (≥9.0%)]; in this group, injectable therapy showed trends toward greater glycaemic control benefits. Additional research into the phenomenon of intensification inertia is warranted.

An exploratory analysis of alkaline phosphatase, lactate dehydrogenase, and prostate-specific antigen dynamics in the phase 3 ALSYMPCA trial with radium-223.

Background: Baseline clinical variables are prognostic for overall survival (OS) in patients with castration-resistant prostate cancer (CRPC). Their prognostic and predictive value with agents targeting bone metastases, such as radium-223, is not established. Patients and methods: The radium-223 ALSYMPCA trial enrolled patients with CRPC and symptomatic bone metastases. Prognostic potential of baseline variables was assessed using Cox models. Percentage changes in biomarker levels from baseline were evaluated during the trial period; changes from baseline to week 12 were evaluated for association with OS and surrogacy. Results: Eastern Cooperative Oncology Group performance status, total alkaline phosphatase (tALP), lactate dehydrogenase (LDH), and prostate-specific antigen (PSA) at baseline were associated with OS (P ≤ 0.0003) in the intent-to-treat population (radium-223, N = 614; placebo, N = 307). tALP declined from baseline within 4 weeks after beginning radium-223, by week 12 declining in 87% of radium-223 and 23% of placebo patients (P < 0.001). LDH declined in 51% and 34% (P = 0.003), whereas PSA declined in 27% and 14% (P = 0.160). Mean tALP change from baseline was 32.2% decrease with radium-223 and 37.2% increase with placebo. Radium-223 patients with tALP decline from baseline to week 12 (confirmed ≥3 weeks from week 12) had 55% lower risk of death (hazard ratio = 0.45; 95% CI 0.34-0.61) versus those with no confirmed tALP decline. Proportional treatment effect (PTE) values for tALP, LDH, and PSA changes from baseline at week 12 as OS surrogate markers were 0.34 (95% CI: 0-0.746), 0.07 (95% CI: 0-0.211), and 0 (95% CI: 0-0.082), respectively. Conclusions: Significant tALP declines (versus placebo) occurred as early as 4 weeks after beginning radium-223 therapy. tALP or LDH declines at 12 weeks correlated with longer OS, but did not meet statistical surrogacy requirements. Dynamic changes in tALP and LDH during radium-223 treatments may be useful to monitor, but do not serve as surrogates for survival.

High PSA anxiety and low health literacy skills: drivers of early use of salvage ADT among men with biochemically recurrent prostate cancer after radiotherapy?

BACKGROUND: Although commonly used, early initiation of salvage androgen deprivation therapy (ADT) has not been proven to enhance survival. We evaluated whether prostate-specific antigen (PSA) anxiety or health literacy are associated with use of early salvage ADT among men with recurrent prostate cancer after radiotherapy. PATIENTS AND METHODS: The prospective Comprehensive, Observational, Multicenter, Prostate Adenocarcinoma Registry was used to study 375 men with biochemically recurrent prostate cancer after external beam radiation or brachytherapy. Multivariable logistic regression was used to determine whether PSA anxiety and health literacy are associated with salvage ADT as initial management after biochemical recurrence. RESULTS: Sixty-eight men (18.1%) received salvage ADT as initial management for PSA recurrence. Men with high PSA anxiety were twice as likely to receive salvage ADT compared with men who did not have high PSA anxiety on both univariable [28.8% versus 13.1%; odds ratio (OR) 2.15; 95% confidence interval (CI) 1.16-4.00; P = 0.015] and multivariable analysis [adjusted OR (AOR) 2.36; 95% CI 1.21-4.62; P = 0.012]. Furthermore, men who had higher levels of health literacy were nearly half as likely to undergo salvage ADT compared with men who had lower levels of health literacy on univariable analysis (15.2% versus 26.3%; OR 0.50; 95% CI 0.29-0.88; P = 0.016), with a trend toward this association on multivariable analysis (AOR 0.58; 95% CI 0.32-1.05; P = 0.07). CONCLUSIONS: Among men with PSA recurrence after radiotherapy, odds of use of salvage ADT were nearly twice as great among men with high PSA anxiety or low health literacy, suggesting that these men are receiving higher rates of unproven treatment. Given that early salvage ADT is costly, worsens quality of life, and has not been shown to improve survival, quality improvement strategies are needed for these individuals.

Deriving benefit of early detection from biomarker-based prognostic models.

Many prognostic models for cancer use biomarkers that have utility in early detection. For example, in prostate cancer, models predicting disease-specific survival use serum prostate-specific antigen levels. These models typically show that higher marker levels are associated with poorer prognosis. Consequently, they are often interpreted as indicating that detecting disease at a lower threshold of the biomarker is likely to generate a survival benefit. However, lowering the threshold of the biomarker is tantamount to early detection. For survival benefit to not be simply an artifact of starting the survival clock earlier, we must account for the lead time of early detection. It is not known whether the existing prognostic models imply a survival benefit under early detection once lead time has been accounted for. In this article, we investigate survival benefit implied by prognostic models where the predictor(s) of disease-specific survival are age and/or biomarker level at disease detection. We show that the benefit depends on the rate of biomarker change, the lead time, and the biomarker level at the original date of diagnosis as well as on the parameters of the prognostic model. Even if the prognostic model indicates that lowering the threshold of the biomarker is associated with longer disease-specific survival, this does not necessarily imply that early detection will confer an extension of life expectancy.

Gender-specific effects of oral hypoglycaemic agents on cancer risk in type 2 diabetes mellitus.

AIMS: To analyse the association between cancer incidence and oral diabetes therapy (biguanide, sulphonylurea, thiazolidinedione and meglitinide) in men and women with type 2 diabetes mellitus. METHODS: A retrospective analysis of the electronic health record-based Cleveland Clinic Diabetes Registry (25 613 patients) was cross-indexed with the histology-based tumour registry (48 051 cancer occurrences) over an 8-year period (1998-2006). Multiple imputations were used to account for missing data. Cox regression with propensity scores was used to model time for the development of incident cancer in each of the imputed datasets and the results were pooled. RESULTS: During 51 994 person follow-up years, 892 incident cancer cases were identified; prostate (14.5%) and breast (11.7%) malignancies were most frequent. In women, thiazolidinedione use was associated with a 32% decreased cancer risk compared with sulphonylurea use [hazard ratio (HR) 0.68; 95% confidence interval (CI) 0.48-0.97, in the adjusted analysis]. Comparison of insulin secretagogues (sulphonylurea and meglitinide) versus insulin sensitizers (biguanide and thiazolidinedione) demonstrated a 21% decreased cancer risk in insulin sensitizers [HR 0.79 (95% CI 0.64-0.98) in the adjusted analysis]. Oral diabetes therapy showed no significant difference in men. Adjustments were made for age, body mass index (BMI), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, coronary heart disease (CHD), diabetes oral monotherapy, race, gender, haemoglobin A1c, statin use, income, insulin use, glomerular filtration rate (GFR), new diabetes status, prior cancer, prior cerebrovascular accident (stroke or transient ischaemic event), systolic/diastolic blood pressure, tobacco use (ever/never) and the propensity score for receiving a biguanide. CONCLUSIONS: Oral insulin sensitizers, particularly thiazolidinedione, are associated with decreased malignancy risk in women with type 2 diabetes mellitus.

The prognostic value of kidney transplant center report cards.

SRTR report cards provide the basis for quality measurement of US transplant centers. There is limited data evaluating the prognostic value of report cards, informing whether they are predictive of prospective patient outcomes. Using national SRTR data, we simulated report cards and calculated standardized mortality ratios (SMR) for kidney transplant centers over five distinct eras. We ranked centers based on SMR and evaluated outcomes for patients transplanted the year following reports. Recipients transplanted at the 50th, 100th and 200th ranked centers had 18% (AHR = 1.18, 1.13-1.22), 38% (AHR = 1.38, 1.28-1.49) and 91% (AHR = 1.91, 1.64-2.21) increased hazard for 1-year mortality relative to recipients at the top-ranked center. Risks were attenuated but remained significant for long-term outcomes. Patients transplanted at centers meeting low-performance criteria in the prior period had 40% (AHR = 1.40, 1.22-1.68) elevated hazard for 1-year mortality in the prospective period. Centers' SMR from the report card was highly predictive (c-statistics > 0.77) for prospective center SMRs and there was significant correlation between centers' SMR from the report card period and the year following (ρ = 0.57, p < 0.001). Although results do not mitigate potential biases of report cards for measuring quality, they do indicate strong prognostic value for future outcomes. Findings also highlight that outcomes are associated with center ranking across a continuum rather than solely at performance margins.

The risk of overall mortality in patients with Type 2 diabetes receiving different combinations of sulfonylureas and metformin: a retrospective analysis.

AIMS: Sulfonylureas have been shown to increase mortality when used in combination with metformin. This may not be a class effect of sulfonylureas, but rather secondary to differences in properties inherent to the individual sulfonylureas (hypoglycaemic risk, sulfonylurea receptor selectivity and effects on myocardial ischemic preconditioning). The purpose of this study was to assess the risk of overall mortality in patients with Type 2 diabetes treated with different combinations of sulfonylureas and metformin. METHODS: A retrospective cohort study was conducted using an academic health center enterprise-wide electronic health record system to identify 7320 patients with Type 2 diabetes (3768 initiators of glyburide (glibenclamide) and metformin, 2277 initiators of glipizide and metformin and 1275 initiators of glimepiride and metformin), ≥ 18 years of age and not on insulin or a non-insulin injectable at baseline. The patients were followed for mortality by documentation in the electronic health record and Social Security Death Index. Multivariable Cox models with propensity analysis were used to compare cohorts. RESULTS: No statistically significant difference in overall mortality risk was observed among the different combinations of sulfonylureas and metformin: glimepiride and metformin vs. glipizide and metformin (HR 1.03; 95% CI 0.89-1.20), glimepiride and metformin vs. glyburide (glibenclamide) and metformin (HR 1.08; 95% CI 0.90-1.30), or with glipizide and metformin vs. glyburide (glibenclamide) and metformin (HR 1.05; 95% CI 0.95-1.15). CONCLUSIONS: Our results did not identify an increased mortality risk among the different combinations of sulfonylureas and metformin, suggesting that overall mortality is not substantially influenced by the choice of sulfonylurea.

Increase in overall mortality risk in patients with type 2 diabetes receiving glipizide, glyburide or glimepiride monotherapy versus metformin: a retrospective analysis.

AIMS: It remains uncertain if differences in mortality risk exist among the sulfonylureas, especially in patients with documented coronary artery disease (CAD). The purpose of this study was to assess the overall mortality risk of the individual sulfonylureas versus metformin in a large cohort of patients with type 2 diabetes. METHODS: A retrospective cohort study was conducted using an academic health centre enterprise-wide electronic health record (EHR) system to identify 23 915 patients with type 2 diabetes who initiated monotherapy with metformin (N = 12774), glipizide (N = 4325), glyburide (N = 4279) or glimepiride (N = 2537), ≥ 18 years of age, with and without a history of CAD, and not on insulin or a non-insulin injectable at baseline. The patients were followed for mortality by documentation in the EHR and Social Security Death Index. Multivariable Cox models with propensity analysis were used to compare cohorts. RESULTS: An increase in overall mortality risk was observed in the entire cohort with glipizide (HR 1.64; 95% CI 1.39-1.94), glyburide (HR 1.59; 95% CI 1.35-1.88), and glimepiride (HR 1.68; 95% CI 1.37-2.06) versus metformin; however, in those patients with documented CAD, a statistically significant increase in overall mortality risk was only found with glipizide (HR 1.41; 95% CI 1.07-1.87) and glyburide (HR 1.38; 95% CI 1.04-1.83) versus metformin. CONCLUSIONS: Glipizide, glyburide and glimepiride are associated with an increased risk of overall mortality versus metformin. Our results suggest that if a sulfonylurea is required to obtain glycaemic control, glimepiride may be the preferred sulfonylurea in those with underlying CAD.

The multinomial logistic regression model for predicting the discharge status after liver transplantation: estimation and diagnostics analysis.

The multinomial logistic regression model (MLRM) can be interpreted as a natural extension of the binomial model with logit link function to situations where the response variable can have three or more possible outcomes. In addition, when the categories of the response variable are nominal, the MLRM can be expressed in terms of two or more logistic models and analyzed in both frequentist and Bayesian approaches. However, few discussions about post modeling in categorical data models are found in the literature, and they mainly use Bayesian inference. The objective of this work is to present classic and Bayesian diagnostic measures for categorical data models. These measures are applied to a dataset (status) of patients undergoing kidney transplantation.

Ki-67 and outcome in clinically localised prostate cancer: analysis of conservatively treated prostate cancer patients from the Trans-Atlantic Prostate Group study.

Treatment decisions after diagnosis of clinically localised prostate cancer are difficult due to variability in tumour behaviour. We therefore examined one of the most promising biomarkers in prostate cancer, Ki-67, in a cohort of 808 patients diagnosed with prostate cancer between 1990 and 1996 and treated conservatively. Ki-67 expression was assessed immunohistochemically, in two laboratories, by two different scoring methods and the results compared with cancer-specific and overall survival. The power of the biomarker was compared with Gleason score and initial serum prostate-specific antigen (PSA). Both methods showed that Ki-67 provided additional prognostic information beyond that available from Gleason score and PSA: for the semi-quantitative method, Deltachi(2) (1 d.f.)=24.6 (P<0.0001), overall survival chi(2)=20.5 (P<0.0001), and for the quantitative method, Deltachi(2) (1 d.f.)=15.1 (P=0.0001), overall survival chi(2)=10.85 (P=0.001). Ki-67 is a powerful biomarker in localised prostate cancer and adds to a model predicting the need for radical or conservative therapy. As it is already in widespread use in routine pathology, it is confirmed as the most promising biomarker to be applied into routine practice.

Nomograms for predicting graft function and survival in living donor kidney transplantation based on the UNOS Registry.

PURPOSE: We developed nomograms that predict transplant renal function at 1 year (Modification of Diet in Renal Disease equation [estimated glomerular filtration rate]) and 5-year graft survival after living donor kidney transplantation. MATERIALS AND METHODS: Data for living donor renal transplants were obtained from the United Network for Organ Sharing registry for 2000 to 2003. Nomograms were designed using linear or Cox regression models to predict 1-year estimated glomerular filtration rate and 5-year graft survival based on pretransplant information including demographic factors, immunosuppressive therapy, immunological factors and organ procurement technique. A third nomogram was constructed to predict 5-year graft survival using additional information available by 6 months after transplantation. These data included delayed graft function, any treated rejection episodes and the 6-month estimated glomerular filtration rate. The nomograms were internally validated using 10-fold cross-validation. RESULTS: The renal function nomogram had an r-square value of 0.13. It worked best when predicting estimated glomerular filtration rate values between 50 and 70 ml per minute per 1.73 m(2). The 5-year graft survival nomograms had a concordance index of 0.71 for the pretransplant nomogram and 0.78 for the 6-month posttransplant nomogram. Calibration was adequate for all nomograms. CONCLUSIONS: Nomograms based on data from the United Network for Organ Sharing registry have been validated to predict the 1-year estimated glomerular filtration rate and 5-year graft survival. These nomograms may facilitate individualized patient care in living donor kidney transplantation.

How accurate are present risk group assignment tools in penile cancer?

OBJECTIVES: To evaluate the accuracy of the predictive models available to estimate the risk of lymph node metastases and cancer-specific survival in patients with squamous cell carcinoma of the penis. METHODS: A nonsystematic review of the literature was performed searching MEDLINE in January 2008. RESULTS: Most of the authors select patients for early inguinal lymphadenectomy according to the pathologic extension of the primary tumor and its histologic grade, as recommended by the EAU Guidelines and the Solsona risk groups. Although the Solsona risk groups performed slightly better, both risk groups had low predictive accuracy. A nomogram including eight clinical and pathologic variables (tumor thickness, microscopic growth pattern, Broder's grade, presence of vascular or lymphatic embolization, infiltrations of the corpora cavernosa, corpus spongiosum or urethra, and the clinical stage of groin lymph nodes) was developed to estimate the risk of lymph node involvement at follow-up. Two nomograms are currently available able to estimate the 5-year cancer-specific survival probabilities of the patients. The first nomogram included the clinical lymph node stage and the same pathological variables of the primary tumor at penectomy, while the pathological stage of the lymph nodes replaced the clinical one in the second model. All the 3 nomograms had good prognostic accuracy. CONCLUSIONS: Both the Solsona and EAU risk group assessment had low prognostic accuracy, although the Solsona risk groups performed slightly better. The nomograms designed to predict the risk of lymph node metastases showed and cancer-specific survival had good prognostic accuracy but their external validation is still lacking.

A preoperative nomogram for disease recurrence following radical prostatectomy for prostate cancer.

BACKGROUND: Few published studies have combined clinical prognostic factors into risk profiles that can be used to predict the likelihood of recurrence or metastatic progression in patients following treatment of prostate cancer. We developed a nomogram that allows prediction of disease recurrence through use of preoperative clinical factors for patients with clinically localized prostate cancer who are candidates for treatment with a radical prostatectomy. METHODS: By use of Cox proportional hazards regression analysis, we modeled the clinical data and disease follow-up for 983 men with clinically localized prostate cancer whom we intended to treat with a radical prostatectomy. Clinical data included pretreatment serum prostate-specific antigen levels, biopsy Gleason scores, and clinical stage. Treatment failure was recorded when there was clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on a separate sample of 168 men, also from our institution. RESULTS: Treatment failure (i.e., cancer recurrence) was noted in 196 of the 983 men, and the patients without failure had a median follow-up of 30 months (range, 1-146 months). The 5-year probability of freedom from failure for the cohort was 73% (95% confidence interval = 69%-76%). The predictions from the nomogram appeared accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (i.e., comparison of the predicted probability with the actual outcome) of 0.79. CONCLUSIONS: A nomogram has been developed that can be used to predict the 5-year probability of treatment failure among men with clinically localized prostate cancer treated with radical prostatectomy.

Prostate-specific antigen (PSA) and PSA density: racial differences in men without prostate cancer.

BACKGROUND: Many physicians now use serum prostate-specific antigen (PSA) to screen for prostate cancer in asymptomatic men. Whether or not a prostate biopsy should also be performed depends on an accurate definition of what constitutes a normal PSA value. Until recently, studies conducted to establish normal serum PSA values have involved study populations that have included few African-American men. PURPOSE: We sought to compare serum PSA levels and PSA density (i.e., serum PSA level/prostate volume ratio) in African-American and white men without histologic evidence of prostate cancer. METHODS: We reviewed the medical records of 826 consecutive men who underwent one or more prostate biopsies at the Veterans Affairs Medical Center in Shreveport, LA, from January 1993 through December 1995. In this retrospective review, we recorded patient's age, race, serum PSA level, digital rectal examination result, ultrasound-determined prostate volume, indications for biopsy, and biopsy results. Data from a total of 752 consecutive men who were either white or African-American and whose indication for biopsy included a serum PSA of greater than 4.0 ng/mL and/or an abnormal digital rectal examination were analyzed. To examine possible differences in serum PSA level, PSA density, prostate volume, and patient age, the two-sided Student's t test was employed. Multivariate linear regression analysis was used to determine if serum PSA levels were associated with the patient's age, race, or prostate volume in men without prostate cancer. RESULTS: Of the 752 men included in this analysis, 254 had histologic evidence of prostate cancer and 498 did not. Of the 498 men without prostate cancer, 367 (74%) men were white and 131 (26%) were black. There were no racial differences in age or calculated prostate volume. Serum PSA levels and calculated PSA density, however, were significantly (both P < .0001) higher in African-American men that in white men. A multivariate linear regression analysis indicated that race and prostate volume were independent variables associated with serum PSA level. For African-American and white men, serum PSA values of greater than 4 ng/mL were associated with prostate cancer with sensitivities of 89.5% and 81.9%, respectively, and specificities of 38.2% and 52.3%, respectively. CONCLUSION: Among biopsied men without histologic evidence of prostate cancer, African-Americans have a significantly higher PSA level and PSA density than similarly aged white men. IMPLICATIONS: Published criteria for normal PSA level and density have been derived primarily from white men and may not be directly applicable to other populations. Race-specific data are needed to fully optimize PSA as a tumor marker in racial populations that are at high risk for prostate cancer death.

A calcitriol analogue, EB1089, inhibits the growth of LNCaP tumors in nude mice.

Limited options for the treatment of prostate cancer have spurred the search for new therapies. One innovative approach is the use of 1alpha,25-dihydroxyvitamin D3 (calcitriol) analogues to inhibit cancer growth. We demonstrate here that the calcitriol analogue, EB1089, extensively inhibits the growth of LNCaP prostate cancer cells in culture and causes the cells to both accumulate in G0-G1 and undergo apoptosis. Importantly, we found that EB1089 inhibits the growth of LNCaP tumor xenografts in nude mice. Because of these antiproliferative properties in vivo, EB1089 is a potential new therapeutic agent for the treatment of prostate cancer.

Detection of metastatic prostate cancer using a splice variant-specific reverse transcriptase-polymerase chain reaction assay for human glandular kallikrein.

We developed a highly sensitive splice variant-specific reverse transcriptase-PCR (RT-PCR) assay for human glandular kallikrein (hK2) mRNA and tested its ability to detect metastatic disease in men with clinically localized prostate cancer. An RT-PCR assay using primers spanning intron IV and including a significant portion of the 3' untranslated region of the hKLK2 gene, with maximum nonhomology to both hK1 and hK3, was developed. The limit of detection of the assay was five copies of hK2 cDNA and one LNCaP cell in 10(9) lymphoblasts. RT-PCR-hK2 was performed on preoperative peripheral blood specimens from 228 consecutive radical prostatectomy patients as well as 7 metastatic prostate cancer patients and 14 healthy men without prostate cancer. This new RT-PCR-hK2 assay amplifies two distinct fragments. The larger fragment (hK2-U) is approximately 680 bp in length and corresponds to the amplified product of a previously reported splice variant in the splice donor site of intron IV in the hKLK2 gene. The smaller fragment (hK2-L) is approximately 643 bp in length and corresponds to the amplified product of the native hK2 mRNA. Whereas the RT-PCR-hK2-L assay was positive in 71% of our patients with metastatic prostate cancer, 14% of healthy control men also tested positive. By univariate (P = 0.028) and multivariate (P = 0.0269) analysis, which controlled for preoperative PSA, clinical stage, and biopsy Gleason score, RT-PCR-hK2-L status added prognostic information to the prediction of lymph node-positive disease. We have developed a new RT-PCR assay which demonstrates a high sensitivity for detecting hK2 mRNA. Preoperative RT-PCR-hK2-L status helps predict pathological lymph node positivity in patients with clinically localized prostate cancer.

Androgen-independent prostate cancer progression in the TRAMP model.

We previously established the autochthonous transgenic adenocarcinoma mouse prostate (TRAMP) model to facilitate characterization of molecular mechanisms involved in the initiation and progression of prostate cancer. TRAMP mice display high grade prostatic intraepithelial neoplasia or well-differentiated prostate cancer by 10-12 weeks of age. To test the hypothesis that molecular events leading to androgen independence and metastasis can occur early in the natural history of prostate cancer yet remain silent until selective pressures such as androgen deprivation are applied, we have examined the consequences of castration on the initiation and progression to metastatic prostate cancer in TRAMP mice. Cohorts were castrated at 12 weeks of age and sacrificed at 18 (T12/18) or 24 (T12/24) weeks of age, and the development of primary cancer and metastatic disease was compared to noncastrated (T18 and T24) controls. Median T12/18 and T12/24 genitourinary (GU) weight was significantly less than T18 and T24, respectively. In addition, T12/24 GU weight was significantly greater than T12/18. Histological prostate tumors developed in 3 of 7 T12/18 and 8 of 10 T12/24 mice. All tumors that developed in castrated mice were poorly differentiated in contrast to 27% in noncastrated controls. Although castration significantly decreased GU tumor burden, overall progression to poorly differentiated and metastatic disease was not ultimately delayed. These results demonstrate that prostate cancer in the TRAMP model is heterogeneous with respect to androgen dependence as early as 12 weeks of age; therefore, early androgen ablation may have a variable impact on progression in an individual mouse. Further analysis of this prostate cancer model to identify specific molecular mechanisms that determine androgen sensitivity may facilitate future initiation of appropriate individualized hormonal therapy for the management of human prostate cancer.

Postoperative nomogram for disease recurrence after radical prostatectomy for prostate cancer.

PURPOSE: Although models exist that place patients into discrete groups at various risks for disease recurrence after surgery for prostate cancer, we know of no published work that combines pathologic factors to predict an individual's probability of disease recurrence. Because clinical stage and biopsy Gleason grade only approximate pathologic stage and Gleason grade in the prostatectomy specimen, prediction of prognosis should be more accurate when postoperative information is added to preoperative variables. Therefore, we developed a postoperative nomogram that allows more accurate prediction of probability for disease recurrence for patients who have received radical prostatectomy as treatment for prostate cancer, compared with the preoperative nomogram we previously published. PATIENTS AND METHODS: By Cox proportional hazards regression analysis, we modeled the clinical and pathologic data and disease follow-up for 996 men with clinical stage T1a-T3c NXM0 prostate cancer who were treated with radical prostatectomy by a single surgeon at our institution. Prognostic variables included pretreatment serum prostate-specific antigen level, specimen Gleason sum, prostatic capsular invasion, surgical margin status, seminal vesicle invasion, and lymph node status. Treatment failure was recorded when there was either clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on this set of men and a separate sample of 322 men from five other surgeons' practices from our institution. RESULTS: Cancer recurrence was noted in 189 of the 996 men, and the recurrence-free group had a median follow-up period of 37 months (range, 1 to 168 months). The 7-year recurrence-free probability for the cohort was 73% (95% confidence interval, 68% to 76%). The predictions from the nomogram appeared to be accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (ie, a comparison of the predicted probability with the actual outcome) of 0.89. CONCLUSION: A postoperative nomogram has been developed that can be used to predict the 7-year probability of disease recurrence among men treated with radical prostatectomy.

Pretreatment nomogram for predicting the outcome of three-dimensional conformal radiotherapy in prostate cancer.

PURPOSE: Several studies have defined risk groups for predicting the outcome after external-beam radiotherapy of localized prostate cancer. However, most models formed patient risk groups, and none of these models considers radiation dose as a predictor variable. The purpose of this study was to develop a nomogram to improve the accuracy of predicting outcome after three-dimensional conformal radiotherapy. MATERIALS AND METHODS: This study was a retrospective, nonrandomized analysis of patients treated at the Memorial Sloan-Kettering Cancer Center between 1988 and 1998. Clinical parameters of the 1,042 patients included stage, biopsy Gleason score, pretreatment serum prostate-specific antigen (PSA) level, whether neoadjuvant androgen deprivation therapy was administered, and the radiation dose delivered. Biochemical (PSA) treatment failure was scored when three consecutive rises of serum PSA occurred. A nomogram, which predicts the probability of remaining free from biochemical recurrence for 5 years, was validated internally on this data set using a bootstrapping method and externally using a cohort of patients treated at the Cleveland Clinic, Cleveland, OH. RESULTS: When predicting outcomes for patients in the validation data set from the Cleveland Clinic, the nomogram had a Somers' D rank correlation between predicted and observed failure times of 0.52. Predictions from this nomogram were more accurate (P<.0001) than the best of seven published risk stratification systems, which achieved a Somers' D coefficient of 0.47. CONCLUSION: The development process illustrated here produced a nomogram that seems to predict more accurately than other available systems and may be useful for treatment selection by both physicians and patients.