Overall survival between African-American (AA) and Caucasian (C) men with metastatic castration-resistant prostate cancer (mCRPC)

LBA5005

Background: Reports have suggested that African-American (AA) men with metastatic castration-resistant prostate cancer (mCRPC) have shorter overall survival (OS) than Caucasian (C) men. Prior reports have been limited by small sample size. The primary goal of this analysis was to compare OS in AA men to Caucasian men treated with docetaxel/prednisone or a docetaxel/prednisone containing regimen. Methods: Individual patient data from 8,871 mCRPC men randomized on nine phase III trials to docetaxel/prednisone (DP) or a DP containing regimen were combined. Race used in the analysis was based on self-report. The primary endpoint is OS, defined as the time between randomization and death or date of last follow-up if patients were alive. The proportional hazards model was used to assess the prognostic importance of race (AA vs. C) adjusting for established risk factors that were common across the trials (age, PSA, performance status, alkaline phosphatase, hemoglobin, and sites of metastases). Results: Of 8,871 patients, 7,528 (85%) were C, 500 (6%) were AA, 424 were Asian (5%) and 419 (4%) had race unspecified. The last two groups were deleted from the analysis leaving 8,452 pts. Median age was 69 years and 94% had performance status 0-1. Median hemoglobin, PSA and alkaline phosphatase were 12.9 g/dL, 86 ng/mL and 139 U/L, respectively. Pattern of metastatic spread were: 72% bone disease with or without lymph nodes, 9% lung disease, 9% liver disease and 7% lymph nodes only. Median OS were 21.0 (95% CI = 19.4-22.5) vs. 21.2 months (95% CI = 20.8-21.7) in AAs and C, respectively. In multivariable analysis adjusting for established risk factors, the pooled hazard ratio (HR) for AAs vs. Caucasians was 0.81 (95% CI = 0.72-0.92, p-value = 0.001) in all patients. Similar results were observed in 4,172 of patients who were treated with DP. Conclusions: We observed a statistically significant increased OS in AA vs. C men with mCRPC who were eligible to be enrolled on these clinical trials. Further understanding the biological variation by race in men with mCRPC treated with DP is warranted.

Patient-reported outcomes for patients with metastatic castration-resistant prostate cancer receiving docetaxel and Atrasentan versus docetaxel and placebo in a randomized phase III clinical trial (SWOG S0421)

Background

SWOG S0421 was a large randomized trial comparing docetaxel/prednisone plus placebo (DPP) to docetaxel/prednisone plus atrasentan over 12 cycles for patients with metastatic castration-resistant prostate cancer (mCRPC). The current report presents the PRO results for this trial, an important secondary endpoint.

Methods

The trial specified two primary PRO endpoints. Palliation of worst pain was based on the Brief Pain Inventory (BPI), where a 2 point difference is defined as clinically meaningful. Improvement of functional status was based on the Functional Assessment of Cancer Therapy – Prostate Cancer Trial Outcome Index (FACT-P TOI); a 5-point difference has been defined as clinically meaningful. We compared rates by arm using chi-square tests. Longitudinal analyses using linear mixed models addressed changes by arm over time.

Results

Four-hundred eighty-nine patients on each arm were evaluable for PRO endpoint data. There were no differences by arm in clinically meaningful pain palliation (41.7% for DPP vs. 44.0% for DPA, p = .70) or functional status (24.2% for DPP vs. 28.7% for DPA, p = .13). Longitudinal comparisons indicated no differences over time by arm for BPI Worst Pain scores (0.13 points, p = .23). Patients on the DPA arm had improved functional status of 1.78 points on average, a statistically significant (p = .02) but not clinically meaningful difference.

Conclusions

The SWOG S0421 PRO data showed little evidence of clinically meaningful differences by arm in either pain palliation or functional status.

Electronic supplementary material

The online version of this article (10.1186/s41687-018-0054-5) contains supplementary material, which is available to authorized users.

Fine-mapping of prostate cancer susceptibility loci in a large meta-analysis identifies candidate causal variants

Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling.

Phase III Intergroup Trial of Adjuvant Androgen Deprivation With or Without Mitoxantrone Plus Prednisone in Patients With High-Risk Prostate Cancer After Radical Prostatectomy: SWOG S9921

Purpose Patients with high-risk prostate cancer after radical prostatectomy are at risk for death. Adjuvant androgen-deprivation therapy (ADT) may reduce this risk. We hypothesized that the addition of mitoxantrone and prednisone (MP) to adjuvant ADT could reduce mortality compared with adjuvant ADT alone. Methods Eligible patients had cT1-3N0 prostate cancer with one or more high-risk factors after radical prostatectomy (Gleason score [GS] ≥ 8; pT3b, pT4, or pN+ disease; GS 7 and positive margins; or preoperative prostate-specific antigen [PSA] > 15 ng/mL, biopsy GS score > 7, or PSA > 10 ng/mL plus biopsy GS > 6. Patients with PSA ≤ 0.2 ng/mL after radical prostatectomy were stratified by pT/N stage, GS, and adjuvant radiation plan and randomly assigned to ADT (bicalutamide and goserelin for 2 years) or ADT plus six cycles of MP. The primary end point was overall survival (OS). Median OS was projected to be 10 years in the ADT arm, requiring 680 patients per arm to detect a hazard ratio of 1.30 with 92% power and one-sided α = .05. Results Nine hundred sixty-one eligible intent-to-treat patients were randomly assigned to ADT or ADT + MP from October 1999 to January 2007, when the Data Safety Monitoring Committee recommended stopping accrual as a result of higher leukemia incidence with ADT + MP. Median follow-up was 11.2 years. The 10-year OS estimates were 87% with ADT (expected 50%) and 86% with ADT + MP (hazard ratio, 1.06; 95% CI, 0.79 to 1.43). The 10-year estimate for disease-free survival was 72% for both arms. Prostate cancer was the cause of death in 18% of patients in the ADT arm and 22% in the ADT + MP arm. More patients in the MP arm died of other cancers (36% v 18% in ADT alone arm). Conclusion MP did not improve OS and increased deaths from other malignancies. The DFS and 10-year OS in these patients treated with 2 years of ADT were encouraging compared with historical estimates, although a definitive conclusion regarding value of ADT may not be made without a nontreatment control arm.

Effect of Intravesical Instillation of Gemcitabine vs Saline Immediately Following Resection of Suspected Low-Grade Non-Muscle-Invasive Bladder Cancer on Tumor Recurrence: SWOG S0337 Randomized Clinical Trial

Importance

Low-grade non-muscle-invasive urothelial cancer frequently recurs after excision by transurethral resection of bladder tumor (TURBT).

Objective

To determine whether immediate post-TURBT intravesical instillation of gemcitabine reduces recurrence of suspected low-grade non-muscle-invasive urothelial cancer compared with saline.

Design, Setting, and Participants

Randomized double-blind clinical trial conducted at 23 US centers. Patients with suspected low-grade non-muscle-invasive urothelial cancer based on cystoscopic appearance without any high-grade or without more than 2 low-grade urothelial cancer episodes within 18 months before index TURBT were enrolled between January 23, 2008, and August 14, 2012, and followed up every 3 months with cystoscopy and cytology for 2 years and then semiannually for 2 years. Patients were monitored for tumor recurrence, progression to muscle invasion, survival, and toxic effects. The final date of follow-up was August 14, 2016.

Interventions

Participants were randomly assigned to receive intravesical instillation of gemcitabine (2 g in 100 mL of saline) (n = 201) or saline (100 mL) (n = 205) for 1 hour immediately following TURBT.

Main Outcomes and Measures

The primary outcome was time to recurrence of cancer. Secondary end points were time to muscle invasion and death due to any cause.

Results

Among 406 randomized eligible patients (median age, 66 years; 84.7% men), 383 completed the trial. In the intention-to-treat analysis, 67 of 201 patients (4-year estimate, 35%) in the gemcitabine group and 91 of 205 patients (4-year estimate, 47%) in the saline group had cancer recurrence within 4.0 years (hazard ratio, 0.66; 95% CI, 0.48-0.90; P<.001 by 1-sided log-rank test for time to recurrence). Among the 215 patients with low-grade non-muscle-invasive urothelial cancer who underwent TURBT and drug instillation, 34 of 102 patients (4-year estimate, 34%) in the gemcitabine group and 59 of 113 patients (4-year estimate, 54%) in the saline group had cancer recurrence (hazard ratio, 0.53; 95% CI, 0.35-0.81; P = .001 by 1-sided log-rank test for time to recurrence). Fifteen patients had tumors that progressed to muscle invasion (5 in the gemcitabine group and 10 in the saline group; P = .22 by 1-sided log-rank test) and 42 died of any cause (17 in the gemcitabine group and 25 in the saline group; P = .12 by 1-sided log-rank test). There were no grade 4 or 5 adverse events and no significant differences in adverse events of grade 3 or lower.

Conclusions and Relevance

Among patients with suspected low-grade non-muscle-invasive urothelial cancer, immediate postresection intravesical instillation of gemcitabine, compared with instillation of saline, significantly reduced the risk of recurrence over a median of 4.0 years. These findings support using this therapy, but further research is needed to compare gemcitabine with other intravesical agents.

Trial Registration

clinicaltrials.gov Identifier: NCT00445601.

Circulating microRNAs and treatment response in the Phase II SWOG S0925 study for patients with new metastatic hormone-sensitive prostate cancer

BACKGROUND

Previous studies suggest circulating, blood-based microRNAs (miRNAs) may serve as minimally invasive prostate cancer biomarkers, however there is limited data from prospective clinical trials. Here, we explore the role of candidate plasma miRNAs as potential biomarkers in the SWOG 0925 randomized phase II study of androgen deprivation combined with cixutumumab versus androgen deprivation alone in patients with new metastatic hormone-sensitive prostate cancer.

METHODS

Correlative biospecimens, including circulating tumor cells (CTCs) and plasma for miRNA analysis, were collected at baseline and after 12 weeks on treatment from 50 patients enrolled on SWOG 0925. Circulating microRNAs were quantified using real-time RT-PCR microRNA array that allowed specific analysis of previously identified candidate miRNAs (miR-141, miR-200a, miR-200b, miR-210, and miR-375) as well as discovery analysis to identify new candidate miRNAs. MiRNA levels were correlated to previously reported CTC counts using CellSearch® (Veridex) and with the primary study outcome of 28-week PSA response (≤0.2, 0.2 to ≤4.0, or >4.0 ng/mL), previously shown to correlate with overall survival.

RESULTS

We observed a correlation between baseline circulating miR-141, miR-200a, and miR-375 levels with baseline CTCs. Baseline miR-375 levels were associated with 28-week PSA response (≤0.2, 0.2 to ≤4.0, or >4.0 ng/mL, P = 0.007). Using ROC curve analysis, there was no significant difference between baseline miR-375 and baseline CTC in predicting 28-week PSA response (≤0.2 vs >0.2 ng/mL). To discover novel candidate miRNAs, we analyzed 365 miRNAs for association with the 28-week PSA response endpoint and identified new candidate miRNAs along with the existing candidates miR-375 and miR-200b (P = 0.0012, P = 0.0046, respectively.

CONCLUSIONS

Baseline plasma miR-141, miR-200a, and miR-375 levels are associated with baseline CTC count. Baseline miR-375 was also associated with the trial endpoint of 28-week PSA response. Our results provide evidence that circulating miRNA biomarkers may have value as prognostic biomarkers and warrant further study in larger prospective clinical trials.

Circadian genes and risk of prostate cancer in the prostate cancer prevention trial

Circadian genes have been considered as a possible biological mechanism for the observed relationship between circadian rhythm disruptions and increased risk of hormone-related cancers. In the current study, we investigated the relationship between circadian gene variants and prostate cancer risk and whether reducing bioavailable testosterone modifies the circadian genes-prostate cancer relationship. We conducted a nested case-control study among Caucasian men in the Prostate Cancer Prevention Trial (PCPT), a randomized placebo-controlled clinical trial to assess if finasteride (an androgen bioactivation inhibitor) could prevent prostate cancer. We evaluated the associations between 240 circadian gene variations and prostate cancer risk among 1092 biopsy-confirmed prostate cancer cases and 1089 biopsy-negative controls in the study (642 cases and 667 controls from the placebo group; 450 cases and 422 controls from the finasteride group), stratified by treatment group. Among men in the finasteride group, there were suggestive associations between NPAS2 variants and total prostate cancer risk, with one SNP remaining statistically significant after Bonferroni correction (rs746924, odds ratio [OR] = 1.5, P = 9.6 × 10^-5 ). However, we found little evidence of increased prostate cancer risk (overall or by low/high grade) associated with circadian gene variations in men of the placebo group, suggesting potential modification of genetic effects by treatment. We did not find strong evidence that circadian gene variants influenced prostate cancer risk in men who were not on finasteride treatment. There were suggestive associations between NPAS2 variants and prostate cancer risk among men using finasteride, which warrants further investigations.

Validation of the Association of RECIST Changes With Survival in Men With Metastatic Castration-Resistant Prostate Cancer Treated on SWOG Study S0421

BACKGROUND

Phase 2 trials evaluating new agents for metastatic castration-resistant prostate cancer (mCRPC) have relied on bone scan and prostate-specific antigen changes to assess activity. Given the increasing detection of measurable disease, Response Evaluation Criteria in Solid Tumors (RECIST) changes warrant consideration to evaluate activity. We validated the association of RECIST 1.0 changes with survival in men with mCRPC receiving docetaxel.

PATIENTS AND METHODS

Data for men with measurable disease from the Southwest Oncology Group (SWOG) S0421, a phase 3 trial in men with mCRPC receiving docetaxel and prednisone plus placebo or atrasentan, were used. Cox proportional hazards regression was used to evaluate the association of RECIST 1.0 outcomes within 120 days, ie, unconfirmed partial response (uPR), stable disease, and progressive disease (PD), with overall survival (OS) from day 120, adjusted for prognostic factors.

RESULTS

Overall, 326 men were evaluable for landmark analysis, of whom 23 had PD, 230 stable disease, and 73 uPR. OS beyond day 120 was significantly different (P = .004) among these subgroups, with median (95% confidence interval) OS of 7.1 (3.5-8.8), 13.4 (11.4-15.6), and 16.3 (10.0-19.6) months for those with PD, stable disease, and uPR, respectively. In a multivariable model, the hazard ratio (95% confidence interval) for patients with PD was 2.47 (1.42-4.29) compared to patients with an uPR (P = .002).

CONCLUSION

The association of RECIST 1.0 changes with OS in men with mCRPC receiving docetaxel was validated. Given limitations of bone scan and prostate-specific antigen alterations, improvements in objective RECIST 1.0 changes should be reported in phase 2 trials before launching phase 3 trials.

Parallel (Randomized) Phase II Evaluation of Tivantinib (ARQ197) and Tivantinib in Combination with Erlotinib in Papillary Renal Cell Carcinoma: SWOG S1107

BACKGROUND

Papillary renal cell carcinoma (pRCC) is associated with EGFR expression and activation of MET signaling pathway. A randomized multicenter parallel two-stage phase II trial of MET inhibitor tivantinib alone or in combination with EGFR inhibitor erlotinib was conducted in patients with pRCC.

METHODS

Patients with advanced pRCC and 0-1 prior systemic therapy were randomly assigned to tivantinib 360 mg BID (Arm 1) or tivantinib 360 mg BID plus erlotinib 150 mg daily (Arm 2). Target max accrual was 70 patients (35 per arm) with interim analysis planned after enrollment of 20 patients per arm.

RESULTS

Six % of patients had type 1 pRCC, 42% had type 2, and 52% had no subtype assigned. The study was closed after the first stage when both arms yielded RR of 0%. Median progression free survival (PFS) was 2.0 and 3.9 months, and OS was 10.3 and 11.3 months in Arms 1 and 2 respectively. Treatment was well tolerated. Exome of tumor tissue from 16 patients were successfully sequenced using Agilent SureSelect probes. Only 1 of 16 samples harbored MET mutation. Other mutations associated primarily with type 2 pRCC were noted and included CDKN2A, PBRM1, SETD2, KDM6A, FAT1 and NF2.

CONCLUSIONS

Tivantinib - either alone or in combination with erlotinib has no clinical activity in patients with advanced pRCC. The S1107 cohort had a low proportion of patients with MET alterations. MET remains a reasonable therapeutic target in pRCC, but selection of patient subsets exhibiting MET activation may be required to better benefit from therapy with MET inhibitors.

A Prospective Study of Chronic Inflammation in Benign Prostate Tissue and Risk of Prostate Cancer: Linked PCPT and SELECT Cohorts

Background: We leveraged two trials to test the hypothesis of an inflammation-prostate cancer link prospectively in men without indication for biopsy.Methods: Prostate Cancer Prevention Trial (PCPT) participants who had an end-of-study biopsy performed per protocol that was negative for cancer and who subsequently enrolled in the Selenium and Vitamin E Cancer Prevention Trial (SELECT) were eligible. We selected all 100 cases and sampled 200 frequency-matched controls and used PCPT end-of-study biopsies as "baseline." Five men with PSA > 4 ng/mL at end-of-study biopsy were excluded. Tissue was located for 92 cases and 193 controls. We visually assessed inflammation in benign tissue. We estimated ORs and 95% confidence intervals (CI) using logistic regression adjusting for age and race.Results: Mean time between biopsy and diagnosis was 5.9 years. In men previously in the PCPT placebo arm, 78.1% of cases (N = 41) and 68.2% of controls (N = 85) had at least one baseline biopsy core (∼5 evaluated per man) with inflammation. The odds of prostate cancer (N = 41 cases) appeared to increase with increasing mean percentage of tissue area with inflammation, a trend that was statistically significant for Gleason sum <4+3 disease (N = 31 cases; vs. 0%, >0-<1.8% OR = 1.70, 1.8-<5.0% OR = 2.39, ≥5% OR = 3.31, P_trend = 0.047). In men previously in the finasteride arm, prevalence of inflammation did not differ between cases (76.5%; N = 51) and controls (75.0%; N = 108).Conclusions: Benign tissue inflammation was positively associated with prostate cancer.Impact: This first prospective study of men without biopsy indication supports the hypothesis that inflammation influences prostate cancer development. Cancer Epidemiol Biomarkers Prev; 26(10); 1549-57. ©2017 AACR.

Abstract 1274: Associations between genetic polymorphisms in genes related to estrogen metabolism and function and prostate cancer risk: results from the Prostate Cancer Prevention Trial

Background: Substantial preclinical data corroborate the critical role of estrogen in prostate cancer development; however, epidemiological studies found no associations between circulating estrogen levels and prostate cancer risk. It was hypothesized that intraprostatic estrogen milieu may play a more important role than circulating estrogen in prostate carcinogenesis. Since it is difficult to obtain data on prostatic estrogen levels, we tested the hypothesis indirectly by investigating associations of prostate cancer risk with genetic variations of enzymes that are involved in estrogen synthesis, metabolism and function, and may affect intraprostatic estrogen milieu.

Methods: A panel of 36 potentially functional single nucleotide polymorphisms (SNPs) in estrogen-related genes was assembled based on information obtained in the literature. After removing SNPs with call rate &lt;95% (1 SNP) or minor allele frequency &lt;3% (10 SNPs), a total of 25 SNPs in 13 genes (PGR, ESR1, ESR2, CYP17A1, HSD17B1, CYP19A1, CYP1A1, CYP1B1, COMT, UGT1A6, UGT1A10, UGT2B7, UGT2B15) were examined for associations with prostate cancer risk using data and DNA samples from 1617 cases and 1731 controls in the Prostate Cancer Prevention Trial (PCPT). Cases and controls were frequency-matched on age, treatment arm and family history. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) separately in the placebo and finasteride arms, adjusting for age, race and family history. Results were similar when restricting analysis to white men only.

Results: Panels of SNPs that were significantly associated with prostate cancer risk were different according to treatment arm, showing rs1801132 in ESR1, rs700518 in CYP19A1, and rs4124874 in UGT1A6 in the placebo arm and rs2445765 in CYP19A1 and rs4680 in COMT in the finasteride arm. When stratified by circulating estrogen and androgen levels, significant associations were only observed in either the high or low category of serum hormone levels; no SNPs were significantly associated with prostate cancer risk in both categories. CYP19A1 was the only gene harboring SNPs that were significantly associated with prostate cancer risk in both the placebo (rs700518) and finasteride arms (rs2445765). In haplotype analysis using all three CYP19A1 SNPs genotyped in the study (rs700518, rs2445765 and rs700519), compared with non-risk haplotype (GCC), certain CYP19A1 haplotypes were significantly associated with increased prostate cancer risk in both arms.

Conclusion: Associations between prostate cancer risk and SNPs in genes involved in estrogen metabolism and function are complicated, and markedly modified by other factors such as finasteride treatment or circulating hormone levels. Supported by grant U10CA37429, 5UM1CA182883 and P01CA108964 from the NCI.

Citation Format: Li Tang, Mary Platek, Song Yao, Cathee Till, Phyllis Goodman, Catherine M. Tangen, Yue Wu, Elizabeth A. Platz, Marian L. Neuhouse, Frank Z. Stanczyk, Juergen K. Reichardt, Regina M. Santella, Ann Hsing, William D. Figg, Scott M. Lippman, Ian M. Thompson, Christine B. Ambrosone. Associations between genetic polymorphisms in genes related to estrogen metabolism and function and prostate cancer risk: results from the Prostate Cancer Prevention Trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1274. doi:10.1158/1538-7445.AM2017-1274

Association between variants in genes involved in the immune response and prostate cancer risk in men randomized to the finasteride arm in the Prostate Cancer Prevention Trial

BACKGROUND

We reported that some, but not all single nucleotide polymorphisms (SNPs) in select immune response genes are associated with prostate cancer, but not individually with the prevalence of intraprostatic inflammation in the Prostate Cancer Prevention Trial (PCPT) placebo arm. Here, we investigated whether these same SNPs are associated with risk of lower- and higher-grade prostate cancer in men randomized to finasteride, and with prevalence of intraprostatic inflammation among controls. Methods A total of 16 candidate SNPs in IL1β, IL2, IL4, IL6, IL8, IL10, IL12(p40), IFNG, MSR1, RNASEL, TLR4, and TNFA and 7 tagSNPs in IL10 were genotyped in 625 white prostate cancer cases, and 532 white controls negative for cancer on an end-of-study biopsy nested in the PCPT finasteride arm. We used logistic regression to estimate log-additive odds ratios (OR) and 95% confidence intervals (CI) adjusting for age and family history.

RESULTS

Minor alleles of rs2243250 (T) in IL4 (OR = 1.46, 95% CI 1.03-2.08, P-trend = 0.03), rs1800896 (G) in IL10 (OR = 0.77, 95% CI 0.61-0.96, P-trend = 0.02), rs2430561 (A) in IFNG (OR = 1.33, 95% CI 1.02-1.74; P-trend = 0.04), rs3747531 (C) in MSR1 (OR = 0.55, 95% CI 0.32-0.95; P-trend = 0.03), and possibly rs4073 (A) in IL8 (OR = 0.81, 95% CI 0.64-1.01, P-trend = 0.06) were associated with higher- (Gleason 7-10; N = 222), but not lower- (Gleason 2-6; N = 380) grade prostate cancer. In men with low PSA (<2 ng/mL), these higher-grade disease associations were attenuated and/or no longer significant, whereas associations with higher-grade disease were apparent for minor alleles of rs1800795 (C: OR = 0.70, 95% CI 0.51-0.94, P-trend = 0.02) and rs1800797 (A: OR = 0.72, 95% CI 0.53-0.98, P-trend = 0.04) in IL6. While some IL10 tagSNPs were associated with lower- and higher-grade prostate cancer, distributions of IL10 haplotypes did not differ, except possibly between higher-grade cases and controls among those with low PSA (P = 0.07). We did not observe an association between the studied SNPs and intraprostatic inflammation in the controls.

CONCLUSION

In the PCPT finasteride arm, variation in genes involved in the immune response, including possibly IL8 and IL10 as in the placebo arm, may be associated with prostate cancer, especially higher-grade disease, but not with intraprostatic inflammation. We cannot rule out PSA-associated detection bias or chance due to multiple testing.

Everolimus (EVE) exposure as a predictor of toxicity (Tox) in renal cell cancer (RCC) patients (Pts) in the adjuvant setting: Results of a pharmacokinetic analysis for SWOG S0931 (EVEREST), a phase III study (NCT01120249)

4566

Background: S0931 is assessing recurrence-free survival in RCC pts randomized to receive EVE versus placebo for one year following nephrectomy. To date, there has been a higher than expected dropout rate due to bothersome tox. Previous reports have shown an association between EVE trough levels and both tox and disease response in RCC pts. Therefore, we have assessed EVE trough levels to evaluate the relationship between measured exposure and probability of tox. This analysis has been approved by the DSMC. Methods: Patients received 10 mg daily EVE or placebo for nine 6-week cycles. Pre-dose whole blood samples collected pre-cycle 2 and pre-cycle 3 were analyzed for EVE. Pts with pre-cycle 2 and/or pre-cycle 3 EVE results were used in the analysis. When both trough levels were available, results were averaged. Pts were segregated into quartiles (Q) based on EVE levels and logistic regression was used to model the following adverse event outcomes using EVE trough as a predictor; any grade 3+ tox, grade 2+ triglycerides, grade 2+ hyperglycemia, grade 2+ oral mucositis, grade 2+ rash, and premature stopping of EVE. Hazard and odds ratios were adjusted for age, BMI and performance status. Results: This study reached its accrual goal and closed on 9/15/2016 with 1545 (775 EVE) randomized patients. A total of 386 pts are included in this preliminary analysis. Median EVE trough was 12.8 ng/mL (range 3.1, 75.6) per 10 mg dose. Event rates for tox were: any grade 3+ tox = 46%, grade 2+ triglycerides = 33%, grade 2+ hyperglycemia = 15%, grade 2+ oral mucositis = 34%, grade 2+ rash = 15%, and premature stopping of EVE = 40%. The risk of grade 2+ triglycerides was increased in Q2 and Q3 vs Q1 (OR = 2.95; p = 0.001 and OR = 3.48; p < 0.001). The risk of grade 2+ rash was increased in Q2 and Q4 vs Q1 (OR = 2.95; p = 0.02 and OR = 3.20; p = 0.01). There was also a trend towards an increased risk of any grade 3+ tox in Q3 vs Q1 (OR = 1.72; p = 0.07). Conclusions: This analysis has identified significant associations between EVE exposure and the probability of tox. EVE analysis is ongoing and the final results will be presented. Clinical trial information: NCT01120249.

The scientific impact and value of large, NCI-sponsored randomized phase III cancer prevention trials

1541

Background: The cooperative cancer research groups of the National Cancer Institute’s National Clinical Trials Network have a history of successful conduct of large randomized phase III trials of prevention for cancer. An important question for funding agencies is whether the conduct of large prevention trials provides strong scientific return on investment. Methods: We used study data from a single NCI-sponsored cooperative group (SWOG) over a 20-year period (1990-2009, inclusive). During this time, SWOG conducted two large prevention trials (the Prostate Cancer Prevention Trial and the Selenium and Vitamin E Cancer Prevention Trial) and numerous treatment trials. Scientific impact for prevention and treatment trials was examined using citation analysis. Average annual citation counts were compared using t-tests. Scientific impact was also assessed as a function of trial costs. Results: Twenty-six treatment trials with 16,391 patients and two prevention trials with 54,415 patients were examined. The mean annual citation rate for primary articles was higher for prevention trials compared to treatment trials (173.6 vs. 41.7, p = .003). For both primary and secondary article publications, mean annual citations for articles associated with prevention trials were also higher (557.2 vs. 67.6, p < .0001). Large prevention trials were estimated to provide 70% greater scientific impact on a cost-adjusted basis. Conclusions: Based on these criteria, the scientific impact of large phase III cancer prevention trials was very high in absolute terms and after accounting for trial costs. For appropriate scientific questions, large prevention trials provide a strong scientific return on investment for federal funding agencies.

Adjuvant androgen deprivation (AD) +/- mitoxantrone + prednisone (MP) in patients with high-risk prostate cancer (PC) post radical prostatectomy (RP): Phase III intergroup trial S9921

5019

Background: Patients (pts) with high-risk PC post RP are at risk of systemic relapse with related morbidity/mortality. Adjuvant AD can reduce this risk. In 1999, based on available data, we hypothesized that adjuvant MP + 2 years (ys) of AD can further reduce mortality. Methods: Eligible pts had cT1-T3, N0 PC with post RP > = 1 high risk factors defined as Gleason sum (GS) ≥ 8, pT3b, pT4, pN+, GS 7 + positive margin or any of these preoperative findings (in pts with neoadjuvant AD): preoperative PSA of > 15 ng/ml, bx GS score > 7, or PSA of > 10 ng/ml + bx GS > 6. Pts had to have post RP PSA = < 0.2 ng/ml, were stratified by T, N, GS, and adjuvant radiation plan and randomized: Arm 1 AD (bicalutamide + goserelin for 2 ys) or Arm 2 AD + 6 cycles m 12 mg/m2 + P 5mg BID. Primary endpoint: overall survival (OS). Median OS was estimated to be 10 ys in AD arm requiring 680 pts/arm to detect a hazard ratio (HR) of 1.30 with 92% power and one-sided α = 0.05. Results: 983 pts (961 eligible intent to treat) with median age 60 ys and median PSA 7.6 ng/ml were randomized to AD or AD + MP from 10/99 -1/07 when the DSMC recommended stopping accrual due to higher leukemia rate in Arm 2. 16% had N1 (Group “Gr” 1), 61% GS ≥8 or pT3b (Gr 2),23% other risk factors (Gr 3). Median time to testosterone recovery was 9.5 months. Median follow-up (f/u) 11.2 ys. Conclusions: OS was higher than anticipated in both arms; MP did not improve OS and increased other malignancy risk. These data illustrate that systemic therapy benefit cannot be extrapolated from different disease stages and the importance of adequate f/u in adjuvant PCa trials. The remarkable DFS and 10 y OS, irrespective of risk extent, may be result of risk definition, and/or 2 ys AD. Pending definitive data 2 ys adjuvant AD for high-risk PCa post RP is a reasonable option to consider. Clinical trial information: NCT00004124. [Table: see text]

A randomized, phase II efficacy assessment of multiple MET kinase inhibitors in metastatic papillary renal carcinoma (PRCC): SWOG S1500

TPS4599

Background: PRCC constitutes approximately 15% of RCC cases, and no standard of care exists for metastatic disease. Approved VEGF- and mTOR-directed therapies for clear cell RCC in metastatic PRCC (mPRCC) have generally been ineffective. Trials assessing sunitinib and everolimus in non-clear cell RCC show a numerical advantage in progression-free survival (PFS) with sunitinib therapy. Prospective studies evaluating sunitinib in mPRCC show a broad range of efficacy, with PFS ranging from 1.6-6.6 months. Another possible approach to treating mPRCC is to target the MET protooncogene, which is frequently altered across both type I and type II disease. SWOG 1500 is a randomized, phase II study which will compare sunitinib to three MET-directed therapies in pts with mPRCC. Methods: Eligible pts will have PRCC (type I, type II or NOS), Zubrod performance status 0-1, and measurable metastatic disease. Pts may have received up to 1 prior systemic therapy, with the exception of prior VEGF-directed treatments. Treated brain metastases are allowed. Tissue must be available for central pathologic review of papillary subtype. Pts will receive either oral sunitinib, cabozantinib, crizotinib or savolitinib in a 1:1:1:1 randomization, with stratification by (1) prior therapy (0 vs 1) and (2) PRCC subtype (type I vs type II vs NOS). The primary endpoint of the study is to compare PFS with sunitinib to PFS with MET-directed therapies. Secondary endpoints in the study include comparison of response rate, overall survival and safety profile. Translational aims of the study include correlation of clinical outcome with MET mutation, copy number and other markers of MET signaling. Radiographic assessment will be performed every 12 wks. Interim analyses are planned for each arm. A total of 275 pts will be enrolled, with 26 pts registered as of Jan 30, 2017. Clinical trial information: NCT02761057.

Adjuvant androgen deprivation (ADT) versus mitoxantrone plus prednisone (MP) plus ADT in high-risk prostate cancer (PCa) patients following radical prostatectomy: A phase III intergroup trial (SWOG S9921) NCT00004124

2

Background: High risk localized Pca patients are more likely to relapse and suffer morbidity/mortality from metastatic disease after prostatectomy. Adjuvant ADT can reduce this risk. We hypothesized that MP in addition to two years of ADT could further reduce mortality from PCa. Methods: Participants with clinically localized (T1-T3, N0, M0) PCa received radical prostatectomy. Eligibility required ≥ 1 high risk criteria defined as Gleason sum ≥8; pT3b or pT4 or N1; Gleason 7 with positive margin; any one of these preoperative findings: PSA>15ng/ml, biopsy Gleason >7, biopsy Gleason >6 with PSA>10. ADT arm consisted of bicalutamide and goserelin for 2 years. ADT+MP arm received ADT plus 6 cycles of M 12mg/m2+ P 5mg BID. Primary endpoint was survival (OS). Median OS was anticipated to be 10 years in ADT arm requiring 680 patients/arm to detect a hazard ratio of 1.30 with 92% power and one-sided α=0.05. Results: S9921 enrolled patients from 10/99 to 1/07 when the DSMC recommended stopping due to increased incidence of leukemia in the ADT+MP arm. Of 983 patients randomized, 22 ineligible. 481 eligible on ADT and 480 on ADT+MP. Patients were stratified by stage (≤pT2, ≥pT3, N0 or N+), Gleason score, and intent to receive adjuvant radiation (RT) (Y/N). Median age was 60 years, 84% were white, presurgical PSA was 7.6 ng/ml, 16% had positive nodes, 26% intended to receive RT, 63% had positive margins. 11 ADT and 20 ADT+ MP received no protocol treatment. Median follow-up is 11.2 years. Conclusions: Survival was greater than anticipated in both arms. MP increases the risk of leukemia. There is no evidence that MP improves PCa specific survival when added to 2 years of adjuvant ADT. Clinical trial information: NCT00004124. [Table: see text]

Selenium and Prostate Cancer: Analysis of Individual Participant Data From Fifteen Prospective Studies

BACKGROUND

Some observational studies suggest that a higher selenium status is associated with a lower risk of prostate cancer but have been generally too small to provide precise estimates of associations, particularly by disease stage and grade.

METHODS

Collaborating investigators from 15 prospective studies provided individual-participant records (from predominantly men of white European ancestry) on blood or toenail selenium concentrations and prostate cancer risk. Odds ratios of prostate cancer by selenium concentration were estimated using multivariable-adjusted conditional logistic regression. All statistical tests were two-sided.

RESULTS

Blood selenium was not associated with the risk of total prostate cancer (multivariable-adjusted odds ratio [OR] per 80 percentile increase = 1.01, 95% confidence interval [CI] = 0.83 to 1.23, based on 4527 case patients and 6021 control subjects). However, there was heterogeneity by disease aggressiveness (ie, advanced stage and/or prostate cancer death, Pheterogeneity = .01), with high blood selenium associated with a lower risk of aggressive disease (OR = 0.43, 95% CI = 0.21 to 0.87) but not with nonaggressive disease. Nail selenium was inversely associated with total prostate cancer (OR = 0.29, 95% CI = 0.22 to 0.40, Ptrend < .001, based on 1970 case patients and 2086 control subjects), including both nonaggressive (OR = 0.33, 95% CI = 0.22 to 0.50) and aggressive disease (OR = 0.18, 95% CI = 0.11 to 0.31, Pheterogeneity = .08).

CONCLUSIONS

Nail, but not blood, selenium concentration is inversely associated with risk of total prostate cancer, possibly because nails are a more reliable marker of long-term selenium exposure. Both blood and nail selenium concentrations are associated with a reduced risk of aggressive disease, which warrants further investigation.

Biases in Recommendations for and Acceptance of Prostate Biopsy Significantly Affect Assessment of Prostate Cancer Risk Factors: Results From Two Large Randomized Clinical Trials

Purpose To identify factors related to who undergoes a prostate biopsy in a screened population and to estimate the impact of biopsy verification on risk factor-prostate cancer associations. Patients and Methods Men who were screened regularly from the placebo arms of two large prostate cancer prevention trials (Prostate Cancer Prevention Trial [PCPT] and Selenium and Vitamin E Cancer Prevention Trial [SELECT]) were examined to define incident prostate cancer cohorts. Because PCPT had an end-of-study biopsy, prostate cancer cases were categorized by a preceding prostate-specific antigen/digital rectal examination prompt (yes/no) and noncases by biopsy-proven negative status (yes v no). We estimated the association of risk factors (age, ethnicity, family history, body mass index, medication use) with prostate cancer and quantified differences in risk associations across cohorts. Results Men 60 to 69 years of age, those with benign prostatic hyperplasia, and those with a family history of prostate cancer were more likely, and those with a higher body mass index (≥ 25), diabetes, or a smoking history were less likely, to undergo biopsy, adjusting for age and longitudinal prostate-specific antigen and digital rectal examination. Medication use, education, and marital status also influenced who underwent biopsy. Some risk factor estimates for prostate cancer varied substantially across cohorts. Black ( v other ethnicities) had odds ratios (ORs) that varied from 1.20 for SELECT (community screening standards, epidemiologic-like cohort) to 1.83 for PCPT (end-of-study biopsy supplemented with imputed end points). Statin use in SELECT provided an OR of 0.65 and statin use in in PCPT provided an OR of 0.99, a relative difference of 34%. Conclusion Among screened men enrolled in prostate cancer prevention trials, differences in risk factor estimates for prostate cancer likely underestimate the magnitude of bias found in other cohorts with varying screening and biopsy recommendations and acceptance. Risk factors for prostate cancer derived from epidemiologic studies not only may be erroneous but may lead to misdirected research efforts.

Adverse Health Events Following Intermittent and Continuous Androgen Deprivation in Patients With Metastatic Prostate Cancer

IMPORTANCE

Although intermittent androgen-deprivation therapy (ADT) has not been associated with better overall survival in prostate cancer (PC), it has the potential for lower adverse effects. To our knowledge, the incidence of long-term adverse health events has not been reported.

OBJECTIVE

To examine long-term late events in elderly patients randomized to intermittent or continuous ADT to determine whether late cardiovascular and endocrine events would be lower in patients treated with intermittent ADT.

DESIGN, SETTING, AND PARTICIPANTS

This was a secondary analysis of a multicenter clinical trial using linkage between patient data from S9346, a randomized SWOG trial of intermittent vs continuous ADT in men with metastatic PC, and corresponding Medicare claims.

EXPOSURE

Intermittent or continuous ADT.

MAIN OUTCOMES AND MEASURES

The main outcome was to identify long-term adverse health events by treatment arm. Patients were classified as having an adverse health event if they had any hospital claim--or at least 2 physician or outpatient claims at least 30 days apart--for any of the following diagnoses: ischemic and thrombotic events, endocrine events, sexual dysfunction, dementia, and depression. To incorporate time from beginning of observation through evidence of an event, we determined the cumulative incidence of each event. Competing risks Cox regression was used, adjusting for covariates.

RESULTS

In total, 1134 eligible US-based male patients with metastatic PC were randomized to continuous vs intermittent ADT in the S9346 trial. A total of 636 of trial participants (56%) had at least 1 year of continuous Medicare parts A and B coverage and no health maintenance organization participation. The median age was 71.3 years. The most common long-term events were hypercholesterolemia (31%) and osteoporosis (19%). The 10-year cumulative incidence of ischemic and thrombotic events differed by arm; 24% for continuous and 33%for intermittent ADT (hazard ratio, 0.69; P = .02). There were no statistically significant differences by arm in any other adverse health events.

CONCLUSIONS AND RELEVANCE

Contrary to our hypothesis that intermittent ADT would reduce long-term health-related events compared with continuous ADT, we found that older men assigned to intermittent ADT had no apparent reduction in bone, endocrine, or cognitive events and an increased incidence of ischemic and thrombotic events.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00002651.

Adding genetic risk score to family history identifies twice as many high-risk men for prostate cancer: Results from the prostate cancer prevention trial

BACKGROUND

While family history (FH) has been widely used to provide risk information, it captures only a small proportion of subjects with higher genetic susceptibility. Our objective is to assess whether a genetic risk score (GRS) calculated from prostate cancer (PCa) risk-associated single nucleotide polymorphisms (SNPs) can supplement FH for more effective risk stratification for PCa screening decision-making.

METHODS

A GRS was calculated based on 29 PCa risk-associated SNPs for 4,528 men of European descent in the placebo arm of the Prostate Cancer Prevention Trial (PCPT). At study entry, participants were free of PCa diagnosis. Performance of FH and GRS were measured by observed detection rate of PCa and high-grade PCa (Gleason score ≥7) during the 7-year study.

RESULTS

GRS was a significant predictor of PCa in men with or without a positive FH (P = 1.18 × 10(-4) and P = 4.50 × 10(-16) , respectively). Using FH alone, as expected, the 17% of men who were FH+ had a PCa detection rate that was significantly higher (29.02%) than FH- men (23.43%, P = 0.001). When both FH+ or GRS >1.4 are considered, more than twice as many men (36%) can be classified as higher risk, as evidenced by a significantly higher PCa detection rate (30.98%) than in the remaining men (20.61%, P = 5.30 × 10(-15) ). If targeting only FH+ men, four out of five PCa cases would go undetected, as would a similarly large fraction (∼80%) of high-grade PCa cases. In comparison, if targeting FH+ or GRS >1.4 men, almost half of all PCa cases would be detected, including 45% of high-grade PCa cases.

CONCLUSIONS

A prostate cancer GRS can supplement family history to better identify higher risk men for targeted intervention. Prostate 76:1120-1129, 2016. © 2016 Wiley Periodicals, Inc.

Long-term Consequences of Finasteride vs Placebo in the Prostate Cancer Prevention Trial

BACKGROUND

Finasteride has been found to reduce the risk of low-grade prostate cancer but to have no impact on overall survival. The long-term adverse and beneficial consequences of finasteride have not been examined.

METHODS

We used a linkage between data from the Prostate Cancer Prevention Trial (PCPT) and Medicare claims. Patients were examined by randomized study arm (finasteride vs placebo for 7 years) for long-term consequences of the intervention, including cardiac, endocrine, and sexual dysfunction, depression, diabetes, and benign prostatic hyperplasia (BPH)-related events. To examine time to events, we used cumulative incidence and Cox regression, adjusting for covariates. All statistical tests were two-sided.

RESULTS

A total of 13 935 of 18 880 participants (73.8%) in the PCPT were linked to Medicare claims, with median Medicare follow-up assessment time of 16 years from trial registration. There were no differences between finasteride and placebo participants with respect to important baseline factors or amount of Medicare follow-up assessment time. Finasteride patients had a 10% higher risk of new claims for depression (hazard ratio [HR] = 1.10, 95% confidence interval [CI] = 1.01 to 1.19, P = .04) and a 6% lower risk of procedures for BPH-related events (primarily lower urinary tract symptoms; HR = 0.94, 95% CI = 0.89 to 1.00, P = .03). No other differences were found in rates of long-term consequences of intervention in the two study arms.

CONCLUSIONS

Finasteride use is associated with reduced need for procedures for relief of BPH-related events and a modest increase in depression. Overall, there is little need to worry about long-term noncancer consequences of finasteride use in those who use it for treatment of symptomatic BPH, hair growth, or prevention of cancer.

Association of androgen metabolism gene polymorphisms with prostate cancer risk and androgen concentrations: Results from the Prostate Cancer Prevention Trial

BACKGROUND

Prostate cancer is highly influenced by androgens and genes. The authors investigated whether genetic polymorphisms along the androgen biosynthesis and metabolism pathways are associated with androgen concentrations or with the risk of prostate cancer or high-grade disease from finasteride treatment.

METHODS

A nested case-control study from the Prostate Cancer Prevention Trial using data from men who had biopsy-proven prostate cancer (cases) and a group of biopsy-negative, frequency-matched controls was conducted to investigate the association of 51 single nucleotide polymorphisms (SNPs) in 12 genes of the androgen pathway with overall (total), low-grade, and high-grade prostate cancer incidence and serum hormone concentrations.

RESULTS

There were significant associations of genetic polymorphisms in steroid 5α-reductase 1 (SRD5A1) (reference SNPs: rs3736316, rs3822430, rs1560149, rs248797, and rs472402) and SRD5A2 (rs2300700) with the risk of high-grade prostate cancer in the placebo arm of the Prostate Cancer Prevention Trial; 2 SNPs were significantly associated with an increased risk (SRD5A1 rs472402 [odds ratio, 1.70; 95% confidence interval, 1.05-2.75; Ptrend = .03] and SRD5A2 rs2300700 [odds ratio, 1.94; 95% confidence interval, 1.19-3.18; Ptrend = .01]). Eleven SNPs in SRD5A1, SRD5A2, cytochrome P450 family 1, subfamily B, polypeptide 1 (CYP1B1), and CYP3A4 were associated with modifying the mean concentrations of serum androgen and sex hormone-binding globulin; and 2 SNPs (SRD5A1 rs824811 and CYP1B1 rs10012; Ptrend < .05) consistently and significantly altered all androgen concentrations. Several SNPs (SRD5A1 rs3822430, SRD5A2 rs2300700, CYP3A43 rs800672, and CYP19 rs700519; Ptrend < .05) were significantly associated with both circulating hormone levels and prostate cancer risk.

CONCLUSIONS

Germline genetic variations of androgen-related pathway genes are associated with serum androgen concentrations and the risk of prostate cancer. Further studies to examine the functional consequence of novel causal variants are warranted. Cancer 2016;122:2332-2340. © 2016 American Cancer Society.