Diabetes and Prostate Cancer Outcomes in Men with Nonmetastatic Castration-Resistant Prostate Cancer: Results from the SEARCH Cohort

BACKGROUND

The prognosis of diabetic men with advanced prostate cancer is poorly understood and understudied. Hence, we studied associations between diabetes and progression to metastases, prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) in men with nonmetastatic castration-resistant prostate cancer (nmCRPC).

METHODS

Data from men diagnosed with nmCRPC between 2000 and 2017 at 8 Veterans Affairs Health Care Centers were analyzed using Cox regression to determine HRs and 95% confidence intervals (CI) for associations between diabetes and outcomes. Men with diabetes were classified according to: (i) ICD-9/10 codes only, (ii) two HbA1c values > 6.4% (missing ICD-9/10 codes), and (iii) all diabetic men [(i) and (ii) combined].

RESULTS

Of 976 men (median age: 76 years), 304 (31%) had diabetes at nmCRPC diagnosis, of whom 51% had ICD-9/10 codes. During a median follow-up of 6.5 years, 613 men were diagnosed with metastases, and 482 PCSM and 741 ACM events occurred. In multivariable-adjusted models, ICD-9/10 code-identified diabetes was inversely associated with PCSM (HR, 0.67; 95% CI, 0.48-0.92) while diabetes identified by high HbA1c values (no ICD-9/10 codes) was associated with an increase in ACM (HR, 1.41; 95% CI, 1.16-1.72). Duration of diabetes, prior to CRPC diagnosis was inversely associated with PCSM among men identified by ICD-9/10 codes and/or HbA1c values (HR, 0.93; 95% CI, 0.88-0.98).

CONCLUSIONS

In men with late-stage prostate cancer, ICD-9/10 'code-identified' diabetes is associated with better overall survival than 'undiagnosed' diabetes identified by high HbA1c values only.

IMPACT

Our data suggest that better diabetes detection and management may improve survival in late-stage prostate cancer.

A modeling study to estimate prostate cancer-specific mortality on active surveillance for men with favorable intermediate-risk prostate cancer: Results from the SEARCH cohort

PURPOSE

Limited data exist to help surgeons decide between active surveillance (AS) versus treatment for men with favorable intermediate risk (FIR) prostate cancer. To estimate the theoretical excess risk of prostate cancer-specific mortality (PCSM) with AS versus radical prostatectomy (RP), we determined the risk of PCSM in FIR men undergoing RP and modeled the PCSM risk for AS using a range of increased PSCM scenarios ranging from 1.25x to 2x higher relative to RP.

MATERIALS AND METHODS

We retrospectively reviewed data from men undergoing RP from 1988 to 2017 at 8 Veterans Affairs hospitals within the SEARCH cohort. Men with FIR PC were identified using the NCCN risk criteria. Risk of PCSM at 5, 10, and 15 years after RP was estimated. Using these estimates, PCSM was then modeled for AS using a range of increased risk of PCSM relative to RP ranging from 1.25x to 2x higher.

RESULTS

For the 920 FIR men identified, 5-, 10-, and 15-year survival estimates for PCSM after RP were 99.9%, 99.0%, and 97.8%, respectively. If the risk of PCSM on AS were 1.25-2x greater than RP, there would be 0.54%-2.17% excess risk of PCSM at 15 years.

CONCLUSIONS

The risk of death for FIR after RP is very low. Assuming even modestly increased PCSM with AS versus RP, the excess risk of death for AS in FIR is low even up to 15 years. These data support the consideration of AS as a relatively safe alternative to RP in FIR men, though prospective randomized trials are needed to validate these findings.

Prostate-specific antigen levels of ≤4 and >4 ng/mL and risk of prostate cancer-specific mortality in men with biopsy Gleason score 9 to 10 prostate cancer

BACKGROUND

Defining workup beyond usual clinical practice that may improve treatment outcomes in men with a prostate-specific antigen (PSA) level of ≤4 ng/mL (vs >4 ng/mL) and Gleason score (GS) 9 to 10 prostate cancer (PC) remains to be determined.

METHODS

Between February 25, 1992, and February 25, 2016, 17,632 men with clinical T1-4 PC with a biopsy GS of 6 to 10 underwent radical prostatectomy at a single academic center. Multivariable Fine and Gray regressions were used to evaluate the risk of prostate cancer-specific mortality (PCSM) with an interaction model evaluating the prognostic significance of PSA ≤ 4 ng/mL versus PSA > 4 ng/mL among men with PC with a biopsy GS of 9 to 10 versus ≤8, with adjustments made for the time-dependent use of adjuvant and/or salvage radiation therapy and androgen deprivation therapy (ADT) in addition to known PC prognostic factors.

RESULTS

There was a significant interaction in men with a biopsy GS of 9 to 10 versus ≤8 and a PSA level of ≤4 ng/mL versus >4 ng/mL (adjusted hazard ratio [AHR], 2.87; 95% confidence interval [CI], 1.02-8.08; P = .046). Specifically, among men with a biopsy GS of 9 to 10 and a PSA level of ≤4 ng/mL versus >4 ng/mL, there was a significantly higher rate of PCSM (AHR, 2.59; 95% CI, 1.19-5.67; P = .017); however, there was no significant difference in the risk of PCSM in men with a biopsy GS ≤ 8 and a PSA level of ≤4 ng/mL versus >4 ng/mL (AHR, 0.90; 95% CI, 0.46-1.78; P = .771). Moreover, the time-dependent use of postoperative ADT was also associated with an increased risk of PCSM (AHR, 10.76; 95% CI, 6.88-16.81; P < .0001).

CONCLUSIONS

Some men with PSA ≤ 4 ng/mL and a biopsy GS of 9 to 10 may have pathologic or genetic variants that make them less amenable to a cure with current standards of care. Additional workup assessing for small cell, neuroendocrine, and genetic variants should be considered.

Population-Based Comparison of Different Risk Stratification Systems Among Prostate Cancer Patients

Background

It is not known which risk stratification system has the best discrimination ability for predicting prostate cancer death.

Methods

We identified patients with non-metastatic primary prostate adenocarcinoma diagnosis between 2004 and 2015 using the Surveillance, Epidemiology, and End Results database. Patients were categorized in different risk groups using the three frequently used risk stratification systems of the National Comprehensive Cancer Network guideline (NCCN-g), American Urological Association guideline (AUA-g), and European Association of Urology guideline (EAU-g), respectively. Associations between risk classification and prostate cancer-specific mortality (PCSM) were determined using Kaplan–Meier analyses and multivariable regression with Cox proportional hazards model. Area under the receiver operating characteristics curve (AUC) analyses were used to test the discrimination ability of the three risk grouping systems.

Results

We analyzed 310,062 patients with a median follow-up of 61 months. A total of 36,368 deaths occurred, including 6,033 prostate cancer deaths. For all the three risk stratification systems, the risk groups were significantly associated with PCSM. The AUC of the model relying on NCCN-g, AUA-g, and EAU-g risk stratification systems for PCSM at specifically 8 years were 0.818, 0.793, and 0.689 in the entire population; 0.819, 0.795, and 0.691 in Whites; 0.802, 0.777, and 0.681 in Blacks; 0.862, 0.818, and 0.714 in Asians; 0.845, 0.806, and 0.728 in Chinese patients. Regardless of the age, marital status, socioeconomic status, and treatment modality, AUC of the model relying on NCCN-g and AUA-g for PCSM was greater than that relying on EAU-g; AUC of the model relying on NCCN-g system was greater than that of the AUA-g system.

Conclusions

The NCCN-g and AUA-g risk stratification systems perform better in discriminating PCSM compared to the EAU-g system. The discrimination ability of the NCCN-g system was better than that of the AUA-g system. It is recommended to use NCCN-g to evaluate risk groups for prostate cancer patients and then provide more appropriate corresponding treatment recommendations.

Early-onset prostate cancer is associated with increased risks of disease progression and cancer-specific mortality

OBJECTIVE

Prostate cancer (PCa) incidence has stabilized but not in patients at a young age. We assessed patient characteristics and disease progression in early-onset PCa.

METHODS

A retrospective cohort of 28,039 newly diagnosed PCa patients aged ≥35 years was constructed using the Taiwan Cancer Registry in 2008-2016. Patients were categorized by age at diagnosis (≤54, 55-59, 60-69, 70-74, and ≥75 years). The clinical stage at diagnosis, Gleason score, prostate-specific antigen level at diagnosis, Charlson's comorbidity index, and primary and secondary treatments for PCa were included in the analysis. All-cause mortality and prostate cancer-specific mortality (PCSM) were reported. Hazard ratios (HRs) and 95% confidence intervals (CIs) estimating the risks of death and of receiving secondary cancer treatment were generated by Cox hazard models.

RESULTS

In patients aged ≤54, 55-59, and 60-69 years, about 60% of them in each group were classified into the high-risk, very high-risk, or metastatic group. However, young patients ≤54 years had a higher risk of PCSM than patients aged 60-69 years (HR = 1.22; 95% CI = 1.10-1.49). This trend of an increased risk in PCSM remained for high-risk, very high-risk, or metastatic patients (HR = 1.24; 95% CI = 1.01-1.51), but not in low- or intermediate-risk patients. Besides, young patients diagnosed with high-risk diseases had the highest risk of receiving secondary cancer treatment within 180 days after completing primary treatment among all age groups (HR = 1.32; 95% CI = 1.07-1.63).

CONCLUSIONS

PCa arising in young patients ≤54 years of age, especially those with a high risk or metastatic form, might be more aggressive than that in other age groups.

Cause-specific mortality of low and selective intermediate-risk prostate cancer patients with active surveillance or watchful waiting

Background

Active surveillance or watchful waiting (AS/WW) is increasingly being used as an alternative strategy to radical prostatectomy or radiation therapy for appropriately selected patients with prostate cancer (PCa). However, the prognosis of low-risk and selective intermediate-risk PCa patients after AS/WW is poorly defined. In this study we reviewed the patients registered in the Surveillance, Epidemiology, and End Results (SEER) Program to establish a competing risk nomogram for the prediction of prostate cancer-specific mortality (PCSM).

Methods

The information of patients undergoing AS/WW in the SEER program from 2004 to 2015 was obtained. All patients were ISUP (International Society of Urological Pathology) grade 1 or 2 PCa and also fulfilled the National Comprehensive Cancer Network’s definition of low-risk PCa [prostate specific antigen (PSA) <10 ng/mL and cT2aN0M0 or less)]. A competing risk nomogram was used to analyze the association of tumor characteristics with PCSM and non-PCSM among the PCa patients with AS/WW. All cases were randomly divided into a training cohort and a validation cohort (1:1). A competing risk nomogram was constructed to predict PCSM in PCa patients with AS/WW. The performance of the PCSM nomogram was evaluated using the concordance index (C-index) and calibration curve.

Results

A total of 30,538 PCa patients were identified as low risk or selective intermediate risk with AS/WW. The 10-year cumulative incidence of death from prostate cancer and death from other cause were 2.8% (95% CI: 2.4–3.1%) and 19.3% (95% CI: 17.8–20.5%), respectively. Variables associated with PCSM included age, marital status, PSA, and ISUP grade. The PCSM nomogram had a good performance in both the training and validation cohorts, with a C-index of 0.744 (95% CI: 0.700–0.781, P<0.001) and 0.738 (95% CI: 0.700–0.777, P<0.001), respectively.

Conclusions

Overall, the prognosis was favorable for the low- and selective intermediate-risk PCa patients with AS/WW. The competing risk nomogram yielded a good performance in identifying subgroups of patients with a higher risk of PCSM and potential candidates for AS/WW.

Epithelial Splicing Regulatory Protein (ESPR1) Expression in an Unfavorable Prognostic Factor in Prostate Cancer Patients

Background

To evaluate the role of epithelial splicing regulatory protein 1 (ESRP1) expression in survival prognoses and disease progression for prostate cancer (PC) using The Cancer Genome Atlas (TCGA) dataset and to validate it using patients’ prostatectomy specimens.

Methods

A preliminary investigation into the clinical significance of ESRP1 in PC was conducted using TCGA PC PRAD dataset and then using immunohistochemistry in 514 PC patients’ tissue microarrays of radical prostatectomy specimens. The interpretation of immunohistochemistry was done using its intensity (high vs. low) or the semi-quantitative expression value (H-score, 0–300). The prognostic significance of ESRP1 expression was analyzed for biochemical recurrence (BCR), recurrence-free survival (RFS), overall survival (OS) and cancer-specific survival (CSS) using the Cox proportional-hazards model (p < 0.05).

Results

In the publicly available prostate adenocarcinoma dataset, ESRP1 expression was significantly higher in the tumor samples compared to the normal samples (p < 0.001). Survival analysis showed that the tumor samples in the ESRP1-high group had significantly worse BCR-free survival and RFS compared to the ESRP1-low group (p < 0.05), whereas OS was not (p=0.08). These results were largely consistent with the 514 patients’ clinical data during a median 91.2 months of follow-up. After adjusting for significant prognostic clinicopathological factors, the multivariable models showed that the ESRP1 was a significantly risk factor for CSS (Hazard ratio 3.37, p = 0.034) and for BCR (HR 1.34, p=0.049) without any significance for OS (p=0.464).

Conclusions

The higher ESRP1 expression appeared increased risk of disease progression and cancer-specific death in PC.

Long-term follow-up of a racially and ethnically diverse population of men with localized prostate cancer who did not undergo initial active treatment

Background

There is limited research on the racial/ethnic differences in long‐term outcomes for men with untreated, localized prostate cancer.

Methods

Men diagnosed with localized, Gleason ≤7 prostate cancer who were not treated within 1 year of diagnosis from 1997–2007 were identified. Cumulative incidence rates of the following events were calculated; treatment initiation, metastasis, death due to prostate cancer and all‐cause mortality, accounting for competing risks. The Cox model of all‐cause mortality and Fine‐Gray sub distribution model to account for competing risks were used to test for racial/ethnic differences in outcomes adjusted for clinical factors.

Results

There were 3925 men in the study, 749 Hispanic, 2415 non‐Hispanic white, 559 non‐Hispanic African American, and 202 non‐Hispanic Asian/Pacific Islander (API). Median follow‐up was 9.3 years. At 19 years, overall cumulative incidence of treatment, metastasis, death due to prostate cancer, and all‐cause mortality was 25.0%, 14.7%, 11.7%, and 67.8%, respectively. In adjusted models compared to non‐Hispanic whites, African Americans had higher rates of treatment (HR = 1.39, 95% CI = 1.15–1.68); they had an increased risk of metastasis beyond 10 years after diagnosis (HR = 4.70, 95% CI = 2.30–9.61); API and Hispanic had lower rates of all‐cause mortality (HR = 0.66, 95% CI = 0.52–0.84, and HR = 0.72, 95% CI = 0.62–0.85, respectively), and API had lower rates of prostate cancer mortality in the first 10 years after diagnosis (HR = 0.29, 95% CI = 0.09–0.90) and elevated risks beyond 10 years (HR = 5.41, 95% CI = 1.39–21.11).

Conclusions

Significant risks of metastasis and prostate cancer mortality exist in untreated men beyond 10 years after diagnosis, but are not equally distributed among racial/ethnic groups.

African-American men and prostate cancer-specific mortality: a competing risk analysis of a large institutional cohort, 1989-2015

Significant racial disparities in prostate cancer (PCa) outcomes have been reported, with African-American men (AAM) more likely to endure adverse oncologic outcomes. Despite efforts to dissipate racial disparities in PCa, a survival gap persists and it remains unclear to what extent this disparity can be explained by known clinicodemographic factors. In this study, we leveraged our large institutional database, spanning over 25 years, to investigate whether AAM continued to experience poor PCa outcomes and factors that may contribute to racial disparities in PCa. A total of 7307 patients diagnosed with PCa from 1989 through 2015 were included. Associations of race and clinicodemographic characteristics were analyzed using chi-square for categorical and Mann-Whitney U-test for continuous variables. Racial differences in prostate cancer outcomes were analyzed using competing risk analysis methods of Fine and Gray. Median follow-up time was 106 months. There were 2304 deaths recorded, of which 432 resulted from PCa. AAM were more likely to be diagnosed at an earlier age (median 60 vs. 65 years, P = <0.001) and were more likely to have ≥1 comorbidities (13.6% vs. 7.5%, P < 0.001). In a multivariate competing risk model, adjusted for baseline covariates, AAM experienced significantly higher risk of PCSM compared to NHW men (HR, 1.62, 95% CI, 1.02-2.57, P = 0.03) NHW. Among men diagnosed at an older age (>60 years), racial differences in PCSM were more pronounced, with AAM experiencing higher rates of PCSM (HR, 2.05, 95% CI, 1.26-3.34, P = 0.003). After adjustment of clinicodemographic and potential risk factors, AAM continue to experience an increased risk of mortality from PCa, especially older AAM. Furthermore, AAM are more likely to be diagnosed at an early age and more likely to have higher comorbidity indices.

Gene expression profiling of prostate tissue identifies chromatin regulation as a potential link between obesity and lethal prostate cancer

BACKGROUND

Obese men are at higher risk of advanced prostate cancer and cancer-specific mortality; however, the biology underlying this association remains unclear. This study examined gene expression profiles of prostate tissue to identify biological processes differentially expressed by obesity status and lethal prostate cancer.

METHODS

Gene expression profiling was performed on tumor (n = 402) and adjacent normal (n = 200) prostate tissue from participants in 2 prospective cohorts who had been diagnosed with prostate cancer from 1982 to 2005. Body mass index (BMI) was calculated from the questionnaire immediately preceding cancer diagnosis. Men were followed for metastases or prostate cancer-specific death (lethal disease) through 2011. Gene Ontology biological processes differentially expressed by BMI were identified using gene set enrichment analysis. Pathway scores were computed by averaging the signal intensities of member genes. Odds ratios (ORs) for lethal prostate cancer were estimated with logistic regression.

RESULTS

Among 402 men, 48% were healthy weight, 31% were overweight, and 21% were very overweight/obese. Fifteen gene sets were enriched in tumor tissue, but not normal tissue, of very overweight/obese men versus healthy-weight men; 5 of these were related to chromatin modification and remodeling (false-discovery rate < 0.25). Patients with high tumor expression of chromatin-related genes had worse clinical characteristics (Gleason grade > 7, 41% vs 17%; P = 2 × 10^-4 ) and an increased risk of lethal disease that was independent of grade and stage (OR, 5.26; 95% confidence interval, 2.37-12.25).

CONCLUSIONS

This study improves our understanding of the biology of aggressive prostate cancer and identifies a potential mechanistic link between obesity and prostate cancer death that warrants further study. Cancer 2017;123:4130-4138. © 2017 American Cancer Society.

Statin use and mortality of patients with prostate cancer: a meta-analysis

OBJECTIVE

The aim of this meta-analysis was to investigate the effect of statin use on the mortality of patients with prostate cancer (PCa).

METHODS

An electronic search of PubMed, Embase, and CENTRAL databases from inception to August 2015 was performed to find eligible studies. Articles investigating the association between statin use and mortality of PCa were identified. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using random- or fixed-effects models.

RESULTS

In total, 13 studies that enrolled 100,536 participants were included in this meta-analysis. Results showed that prediagnostic statin use had a significantly lower risk of both all-cause mortality (ACM; HR, 0.56; 95% CI, 0.38-0.83) and PCa-specific mortality (PCSM; HR, 0.53; 95% CI, 0.36-0.77). Similarly, postdiagnostic statin use was correlated with reductions in both ACM (HR, 0.77; 95% CI, 0.69-0.87) and PCSM (HR, 0.64; 95% CI, 0.52-0.79). When stratified by primary treatment, postdiagnostic use of statins had a 0.4-fold lower risk of ACM in patients with PCa who were treated with local therapy; both pre- and postdiagnostic use of statins was correlated with a significantly lower risk of PCSM in patients who were treated with androgen deprivation therapy.

CONCLUSION

Both pre- and postdiagnostic use of statins is associated with better overall survival and PCa-specific survival. This suggests a need for randomized controlled trials of statins in patients with PCa.

Circulating levels of 25-hydroxyvitamin D and prostate cancer prognosis

OBJECTIVES

Ecological, in vitro, and in vivo studies demonstrate a link between vitamin D and prostate tumor growth and aggressiveness. The goal of this study was to investigate whether plasma concentration of vitamin D is associated with survivorship and disease progression in men diagnosed with prostate cancer.

MATERIALS AND METHODS

We conducted a population-based cohort study of 1476 prostate cancer patients to assess disease recurrence/progression and prostate cancer-specific mortality (PCSM) risks associated with serum levels of 25(OH) vitamin D [25(OH)D].

RESULTS

There were 325 recurrence/progression and 95 PCSM events during an average of 10.8 years of follow-up. Serum levels of 25(OH)D were not associated with risk of recurrence/progression or mortality. Clinically deficient vitamin D levels were associated with an increased risk of death from other causes.

CONCLUSIONS

We did not find evidence that serum vitamin D levels measured after diagnosis affect prostate cancer prognosis. Lower levels of vitamin D were associated with risk of non-prostate cancer mortality.