Insulin resistance during androgen deprivation therapy in men with prostate cancer.

BACKGROUND: Androgen deprivation therapy (ADT) in prostate cancer (PCa) has been associated with development of insulin resistance. However, the predominant site of insulin resistance remains unclear. METHODS: The ADT & Metabolism Study was a single-center, 24-week, prospective observational study that enrolled ADT-naive men without diabetes who were starting ADT for at least 24 weeks (ADT group, n = 42). The control group comprised men without diabetes with prior history of PCa who were in remission after prostatectomy (non-ADT group, n = 23). Prevalent diabetes mellitus was excluded in both groups using all three laboratory criteria defined in the American Diabetes Association guidelines. All participants were eugonadal at enrollment. The primary outcome was to elucidate the predominant site of insulin resistance (liver or skeletal muscle). Secondary outcomes included assessments of body composition, and hepatic and intramyocellular fat. Outcomes were assessed at baseline, 12, and 24 weeks. RESULTS: At 24 weeks, there was no change in hepatic (1.2; 95% confidence interval [CI], -2.10 to 4.43; p = .47) or skeletal muscle (-3.2; 95% CI, -7.07 to 0.66; p = .10) insulin resistance in the ADT group. No increase in hepatic or intramyocellular fat deposition or worsening of glucose was seen. These changes were mirrored by those observed in the non-ADT group. Men undergoing ADT gained 3.7 kg of fat mass. CONCLUSIONS: In men with PCa and no diabetes, 24 weeks of ADT did not change insulin resistance despite adverse body composition changes. These findings should be reassuring for treating physicians and for patients who are being considered for short-term ADT.

AI-derived Tumor Volume from Multiparametric MRI and Outcomes in Localized Prostate Cancer.

Background An artificial intelligence (AI)-based method for measuring intraprostatic tumor volume based on data from MRI may provide prognostic information. Purpose To evaluate whether the total volume of intraprostatic tumor from AI-generated segmentations (VAI) provides independent prognostic information in patients with localized prostate cancer treated with radiation therapy (RT) or radical prostatectomy (RP). Materials and Methods For this retrospective, single-center study (January 2021 to August 2023), patients with cT1-3N0M0 prostate cancer who underwent MRI and were treated with RT or RP were identified. Patients who underwent RT were randomly divided into cross-validation and test RT groups. An AI segmentation algorithm was trained to delineate Prostate Imaging Reporting and Data System (PI-RADS) 3-5 lesions in the cross-validation RT group before providing segmentations for the test RT and RP groups. Cox regression models were used to evaluate the association between VAI and time to metastasis and adjusted for clinical and radiologic factors for combined RT (ie, cross-validation RT and test RT) and RP groups. Areas under the receiver operating characteristic curve (AUCs) were calculated for VAI and National Comprehensive Cancer Network (NCCN) risk categorization for prediction of 5-year metastasis (RP group) and 7-year metastasis (combined RT group). Results Overall, 732 patients were included (combined RT group, 438 patients; RP group, 294 patients). Median ages were 68 years (IQR, 62-73 years) and 61 years (IQR, 56-66 years) for the combined RT group and the RP group, respectively. VAI was associated with metastasis in the combined RT group (median follow-up, 6.9 years; adjusted hazard ratio [AHR], 1.09 per milliliter increase; 95% CI: 1.04, 1.15; P = .001) and the RP group (median follow-up, 5.5 years; AHR, 1.22; 95% CI: 1.08, 1.39; P = .001). AUCs for 7-year metastasis for the combined RT group for VAI and NCCN risk category were 0.84 (95% CI: 0.74, 0.94) and 0.74 (95% CI: 0.80, 0.98), respectively (P = .02). Five-year AUCs for the RP group for VAI and NCCN risk category were 0.89 (95% CI: 0.80, 0.98) and 0.79 (95% CI: 0.64, 0.94), respectively (P = .25). Conclusion The volume of AI-segmented lesions was an independent, prognostic factor for localized prostate cancer. © RSNA, 2024 Supplemental material is available for this article.

Acute toxicity comparison of magnetic resonance-guided adaptive versus fiducial or computed tomography-guided non-adaptive prostate stereotactic body radiotherapy: A systematic review and meta-analysis.

BACKGROUND: Stereotactic body radiotherapy (SBRT) is gaining wider adoption for prostate cancer management but there remain significant toxicity risks when delivering prostate SBRT with standard techniques. Magnetic resonance-guided daily adaptive SBRT (MRg-A-SBRT) offers technological advantages in precision of radiation dose delivery, but the toxicity profile associated with MRg-A-SBRT compared to more standardly used fiducial or computed tomography-guided non-adaptive prostate SBRT (CT-SBRT) remains unknown. METHODS: A meta-analysis to compare acute toxicity rates associated with MRg-A-SBRT and CT-SBRT for prostate cancer was performed in compliance with PRISMA guidelines. MEDLINE (PubMed) and Google Scholar were searched for prospective studies of prostate SBRT that were published between January 1, 2018 and August 31, 2022. Random effects and fixed effects models were used to estimate pooled toxicity rates, and meta-regression was performed to compare toxicity between MRg-A-SBRT and CT-SBRT study groups. RESULTS: Twenty-nine prospective studies were identified that met the inclusion criteria and included a total of 2547 patients. The pooled estimates for acute grade 2 or higher (G2+) genitourinary (GU) and gastrointestinal (GI) toxicity for MRg-A-SBRT were 16% (95% confidence interval [CI], 10%-24%) and 4% (95% CI, 2%-7%) and for CT-SBRT they were 28% (95% CI, 23%-33%) and 9% (95% CI, 6%-12%), respectively. On meta-regression, the odds ratios for acute G2+ GU and GI toxicities comparing MRg-A-SBRT and CT-SBRT were 0.56 (95% CI, 0.33-0.97, p = .04) and 0.40 (95% CI, 0.17-0.96, p = .04), respectively. CONCLUSION: MRg-A-SBRT is associated with a significantly reduced risk of acute G2+ GU or GI toxicity compared to CT-SBRT. Longer follow-up will be needed to evaluate late toxicity and disease control outcomes. PLAIN LANGUAGE SUMMARY: Magnetic resonance imaging-guided daily adaptive prostate stereotactic radiation (MRg-A-SBRT) is a treatment that may allow for delivery of prostate radiation more precisely than other radiotherapy techniques, but it is unknown whether this reduces side effects compared to standardly used computed tomography-guided SBRT (CT-SBRT). In this systematic review and meta-analysis combining data from 29 clinical trials including 2547 patients, it was found that the risk of short-term urinary side effects was reduced by 44% and the risk of short-term bowel side effects was reduced by 60% with MRg-A-SBRT compared to CT-SBRT.

MR-guided prostate SBRT in prostate cancer patients with low-volume metastatic disease.

BACKGROUND: Recent data have found an overall survival benefit from prostate-directed radiotherapy in patients with low-volume metastatic prostate cancer. Prostate SBRT is an attractive treatment in this setting and may be optimised with MR-guided adaptive treatment. Here, we share our institutional experience delivering stereotactic MR-guided adaptive prostate SBRT (SMART) for patients with low-volume metastatic disease. METHODS: We reviewed patients with low-volume metastatic disease who received prostate SMART from October 2019 to December 2021 on a 0.35T MR-Linac. The cohort included 14 patients. Genitourinary (GU) and gastrointestinal (GI) toxicities were assessed using CTCAE v 5.0. Progression was defined as a change in systemic or hormonal therapy regimen as a result of PSA rise or disease progression. RESULTS: The median follow-up time was 29 months. Seven patients had hormone sensitive prostate cancer and 7 had castrate resistant prostate cancer (CRPC). 13 patients received 36.25 Gy in 5 fractions and one patient received 33 Gy in 5 fractions. At the time of last follow-up, 11 patients had not experienced progression and three patients, all with CRPC, had experienced progression. No patients developed local progression in the prostate after SMART. One patient experienced acute grade 2 urinary toxicity (7%) and no patients experienced acute grade 2 GI toxicity (0%). No grade 3 + acute toxicities were observed. CONCLUSIONS: Prostate SMART was found to be well tolerated and all patients had local control of disease within the prostate at the time of last follow-up. Prostate SMART may represent a low-risk and well-tolerated approach for delivering prostate-directed radiotherapy for patients with limited metastatic disease.

Comparison of MR-soft tissue based versus biliary stent based alignment for image guidance in pancreatic SBRT.

PURPOSE: The role of biliary stents in image-guided localization for pancreatic cancer has been inconclusive. To date, stent accuracy has been largely evaluated against implanted fiducials on cone beam computed tomography. We aim to use magnetic resonance (MR) soft tissue as a direct reference to examine the geometric and dosimetric impacts of stent-based localization on the newly available MR linear accelerator. METHODS: Thirty pancreatic cancer patients (132 fractions) treated on our MR linear accelerator were identified to have a biliary stent. In our standard adaptive workflow, patients were set up to the target using soft tissue for image registration and structures were re-contoured on daily MR images. The original plan was then projected on treatment anatomy and dose predicted, followed by plan re-optimization and treatment delivery. These online predicted plans were soft tissue-based and served as reference plans. Retrospective image registration to the stent was performed offline to simulate stent-based localization and the magnitude of shifts was taken as the geometric accuracy of stent localization. New predicted plans were generated based on stent-alignment for dosimetric comparison. RESULTS: Shifts were within 3 mm for 90% of the cases (mean = 1.5 mm); however, larger shifts up to 7.2 mm were observed. Average PTV coverage dropped by 1.1% with a maximum drop of 26.8%. The mean increase in V35Gy was 0.15, 0.05, 0.02, and 0.02 cc for duodenum, stomach, small bowel and large bowel, respectively. Stent alignment was significantly worse for all metrics except for small bowel (p = 0.07). CONCLUSIONS: Overall discrepancy between stent- and soft tissue-alignment was modest; however, large discrepancies were observed for select cases. While PTV coverage loss may be compensated for by using a larger margin, the increase in dose to gastrointestinal organs at risk may limit the role of biliary stents in image-guided localization.

Ototoxicity After Cisplatin-Based Chemotherapy: Factors Associated With Discrepancies Between Patient-Reported Outcomes and Audiometric Assessments.

OBJECTIVES: To provide new information on factors associated with discrepancies between patient-reported and audiometrically defined hearing loss (HL) in adult-onset cancer survivors after cisplatin-based chemotherapy (CBCT) and to comprehensively investigate risk factors associated with audiometrically defined HL. DESIGN: A total of 1410 testicular cancer survivors (TCS) ≥6 months post-CBCT underwent comprehensive audiometric assessments (0.25 to 12 kHz) and completed questionnaires. HL severity was defined using American Speech-Language-Hearing Association criteria. Multivariable multinomial regression identified factors associated with discrepancies between patient-reported and audiometrically defined HL and multivariable ordinal regression evaluated factors associated with the latter. RESULTS: Overall, 34.8% of TCS self-reported HL. Among TCS without tinnitus, those with audiometrically defined HL at only extended high frequencies (EHFs) (10 to 12 kHz) (17.8%) or at both EHFs and standard frequencies (0.25 to 8 kHz) (23.4%) were significantly more likely to self-report HL than those with no audiometrically defined HL (8.1%) [odds ratio (OR) = 2.48; 95% confidence interval (CI), 1.31 to 4.68; and OR = 3.49; 95% CI, 1.89 to 6.44, respectively]. Older age (OR = 1.09; 95% CI, 1.07 to 1.11, p < 0.0001), absence of prior noise exposure (OR = 1.40; 95% CI, 1.06 to 1.84, p = 0.02), mixed/conductive HL (OR = 2.01; 95% CI, 1.34 to 3.02, p = 0.0007), no hearing aid use (OR = 5.64; 95% CI, 1.84 to 17.32, p = 0.003), and lower education (OR = 2.12; 95% CI, 1.23 to 3.67, p = 0.007 for high school or less education versus postgraduate education) were associated with greater underestimation of audiometrically defined HL severity, while tinnitus was associated with greater overestimation (OR = 4.65; 95% CI, 2.64 to 8.20 for a little tinnitus, OR = 5.87; 95% CI, 2.65 to 13.04 for quite a bit tinnitus, and OR = 10.57; 95% CI, 4.91 to 22.79 for very much tinnitus p < 0.0001). Older age (OR = 1.13; 95% CI, 1.12 to 1.15, p < 0.0001), cumulative cisplatin dose (>300 mg/m2, OR = 1.47; 95% CI, 1.21 to 1.80, p = 0.0001), and hypertension (OR = 1.80; 95% CI, 1.28 to 2.52, p = 0.0007) were associated with greater American Speech-Language-Hearing Association-defined HL severity, whereas postgraduate education (OR = 0.58; 95% CI, 0.40 to 0.85, p = 0.005) was associated with less severe HL. CONCLUSIONS: Discrepancies between patient-reported and audiometrically defined HL after CBCT are due to several factors. For survivors who self-report HL but have normal audiometric findings at standard frequencies, referral to an audiologist for additional testing and inclusion of EHFs in audiometric assessments should be considered.

Progress and controversies: Radiation therapy for prostate cancer.

Radiation therapy remains a standard treatment option for men with localized prostate cancer. Alone or in combination with androgen-deprivation therapy, it represents a curative treatment and has been shown to prolong survival in selected populations. In this article, the authors review recent advances in prostate radiation-treatment techniques, photon versus proton radiation, modification of treatment fractionation, and brachytherapy-all focusing on disease control and the impact on morbidity. Also discussed are refinements in the risk stratification of men with prostate cancer and how these are better for matching patients to appropriate treatment, particularly around combined androgen-deprivation therapy. Many of these advances have cost and treatment burden implications, which have significant repercussions given the prevalence of prostate cancer. The discussion includes approaches to improve value and future directions for research.

Treating the SARS-CoV-2-positive patient with cancer: A proposal for a pragmatic and transparent ethical process.

The treatment of patients with cancer who test positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses unique challenges. In this commentary, the authors describe the ethical rationale and implementation details for the creation of a novel, multidisciplinary treatment prioritization committee, including physicians, frontline staff, an ethicist, and an infectious disease expert. Organizational obligations to health care workers also are discussed. The treatment prioritization committee sets a threshold of acceptable harm to patients from decreased cancer control that is justified to reduce risk to staff. The creation of an ethical, consistent, and transparent decision-making process involving such frontline stakeholders is essential as departments across the country are faced with decisions regarding the treatment of SARS-CoV-2-positive patients with cancer.

Use and early mortality outcomes of active surveillance in patients with intermediate-risk prostate cancer.

BACKGROUND: Certain patients with intermediate-risk prostate cancer (PCa) may be appropriate candidates for active surveillance (AS). In the current study, the authors sought to characterize AS use and early mortality outcomes for patients with intermediate-risk PCa in the United States. METHODS: The novel Surveillance, Epidemiology, and End Results Active Surveillance/Watchful Waiting database identified 52,940 men diagnosed with National Comprehensive Cancer Network intermediate-risk PCa (cT2b-c, Gleason score of 7, or a prostate-specific antigen level of 10-20 ng/mL) and actively managed (AS, radiotherapy, or radical prostatectomy) from 2010 through 2015. The Cuzick test assessed AS time trends, and logistic multivariable regression characterized features associated with AS. Fine-Gray and Cox modeling determined PCa-specific mortality (PCSM) and overall survival, respectively. RESULTS: The rate of AS increased from 3.7% in 2010 to 7.3% in 2015, and from 7.2% to 11.7% among men aged ≥70 years. Among men with favorable and unfavorable intermediate-risk disease, the use of AS increased from 7.2% to 14.9% and from 2.2% to 3.8%, respectively (all P value for trend, <.001). The mean age of those patients managed with AS decreased from 69.9 years to 67.9 years (P = .0004). Factors found to be associated with AS included favorable risk disease; black race; higher socioeconomic status; older age; and diagnosis in the West, Northwest, or Midwest regions of the United States. The 5-year PCSM rate was comparable to AS versus treatment among patients with low-risk and favorable intermediate-risk disease, but was worse with AS among those with unfavorable intermediate-risk disease (PCSM, 1.3% vs 0.5%; adjusted hazard ratio, 2.48 [95% CI, 1.11-5.50; P = .026]) and intermediate-risk disease overall (PCSM, 1.1% vs 0.4%; adjusted hazard ratio, 2.34 [95% CI, 1.25-4.37; P = .008]). CONCLUSIONS: The use of AS for patients with intermediate-risk PCa is increasing across the United States, particularly for older men and those with favorable intermediate-risk disease. Early estimates of cancer-specific and overall mortality rates are low with AS, although significantly higher compared with treatment.

Practice Patterns and Outcomes Among Patients With N0M0 Prostate Cancer and a Very High Prostate-Specific Antigen Level.

BACKGROUND: Management of patients with a very high prostate-specific antigen (PSA) level (≥98.0 ng/mL) but clinically localized (N0M0) prostate cancer is challenging. This study sought to determine practice patterns and outcomes among these patients. PATIENTS AND METHODS: A total of 748,825 patients with prostate cancer from 2004 through 2012 were identified using the National Cancer Database. These patients were subdivided by PSA level (0-9.9, 10.0-19.9, 20.0-39.9, 40.0-59.9, 60.0-79.9, 80.0-97.9, and ≥98.0 ng/mL), nodal status (N0 vs N1), and distant metastases (M0 vs M1). Rates of locoregional treatment and 5-year overall survival (OS) in each group were determined. Survival was compared using Cox regression after adjusting for multiple patient-specific factors. RESULTS: The rate of locoregional treatment for patients with N0M0 disease and PSA level ≥98.0 ng/mL was significantly lower than for those with N1M0 disease (52.6% vs 60.4%; P<.001) or N0M0 disease and PSA level <98.0 ng/mL (52.6% vs 86.6%; P<.001). The 5-year OS rate was similar for patients with N1M0 disease and those with N0M0 disease and a very high PSA level (63.2% vs 59.1%; adjusted hazard ratio [aHR], 0.91; P=.063). The survival benefit associated with locoregional treatment was higher among those with N0M0 disease and a very high PSA level than among those with N1M0 disease (aHR, 0.28 vs 0.44; P<.001). CONCLUSIONS: Patients with clinical N0M0 disease and a very high PSA level (≥98.0 ng/mL) have outcomes similar to those with N1 disease but receive locoregional treatment at a lower rate. Future work is needed to investigate the utility of locoregional treatment in this population.

Travel distance and stereotactic body radiotherapy for localized prostate cancer.

BACKGROUND: Definitive stereotactic body radiotherapy (SBRT) represents an emerging and debated treatment option for patients with prostate cancer, with potential economic savings and reports of short-term efficacy since 2006. The current study sought to define national trends in definitive prostate SBRT use and determine whether patterns vary by travel distance for treatment. METHODS: The National Cancer Data Base identified 181,544 men with localized prostate cancer who were treated with definitive external beam radiotherapy from 2004 through 2012. Joinpoint regression analyzed definitive prostate SBRT trends over time, whereas multivariable logistic regression defined the odds for its receipt by travel distance for treatment. RESULTS: Definitive prostate SBRT use increased from 1.8% in 2004 to 5.9% in 2012 (P for trend <.0001), with a joinpoint for increased use noted in 2006 (P<.0001). Higher SBRT use was found to be associated with longer travel distance for treatment, younger age, white race, more affluent zip code of residence, academic treatment center, favorable disease characteristics, and fewer comorbidities (all P<.0001). Compared with travel distances <25 miles for treatment, travel distances of 25 to 50 miles and >50 miles were associated with increasing adjusted odds of receipt of definitive prostate SBRT (1.63 [95% confidence interval, 1.51-1.76] and 2.35 [95% confidence interval, 2.14-2.57], respectively; both P < .0001). CONCLUSIONS: Definitive prostate SBRT use increased more than 3-fold since 2004, with a significant increase in use coinciding with early reports of short-term efficacy. Long-distance travel for treatment was associated with greater than twice the odds of receipt of definitive prostate SBRT compared with short-distance travel, suggesting that treatment decisions with unknown long-term clinical implications may be strongly driven by sociodemographic factors. Cancer 2018;124:1141-9. © 2017 American Cancer Society.

Receipt of definitive therapy in elderly patients with unfavorable-risk prostate cancer.

BACKGROUND: Conservative management of aggressive prostate cancer in the elderly without definitive therapy has been associated with a 10-year prostate cancer-specific mortality of approximately 50%. The authors examined the prevalence of definitive therapy in elderly patients with intermediate-risk or high-risk disease. METHODS: 411,343 patients who were diagnosed from 2004 through 2012 with intermediate-risk or high-risk prostate cancer were identified in the National Cancer Database. Multivariable logistic regression adjusting for sociodemographic characteristics and comorbidity was used to examine the association between age and receipt of definitive therapy, defined as radical prostatectomy or radiotherapy, and of primary androgen deprivation therapy (ADT) among patients who did not receive definitive therapy. RESULTS: In total, 87.1% of high-risk patients and 91.9% of intermediate-risk patients received definitive therapy. When stratified by age, 93.7%, 92.1%, 90.8%, 87.6%, 80.9%, and 55.2% of high-risk patients and 96.1%, 94.7%, 93.4%, 89.7%, 82.7%, and 62.8% of intermediate-risk patients ages <60, 60 to 64, 65 to 69, 70 to 74, 75 to 79, and ≥80 years received definitive therapy, respectively. For both high-risk and intermediate-risk patients, increasing age was significantly associated with a decreased likelihood of receiving definitive therapy overall (both P < .001) and a greater likelihood of receiving primary ADT among those who did not receive definitive therapy (both P < .001). CONCLUSIONS: Older age was significantly associated with a decreased likelihood of receiving definitive therapy and an increased likelihood of receiving primary ADT in this national cohort of patients with intermediate-risk or high-risk prostate cancer. Notably, approximately 40% to 45% of patients aged ≥80 years did not receive definitive therapy. These findings are alarming given the dismal outcomes of conservatively managed unfavorable-risk prostate cancer. Cancer 2017;123:4832-40. © 2017 American Cancer Society.

National trends and determinants of proton therapy use for prostate cancer: A National Cancer Data Base study.

BACKGROUND: In the current study, the authors sought to both characterize the national trends in proton therapy use for prostate cancer and determine the factors associated with receipt of this limited resource, using what to the best of their knowledge is the largest nationwide cancer registry. METHODS: The National Cancer Data Base was used to identify 187,730 patients diagnosed with nonmetastatic prostate cancer from 2004 through 2012 who received external beam radiotherapy as their initial form of definitive therapy. Multivariable logistic regression analysis adjusted for sociodemographic and clinical factors was used to identify independent determinants of proton therapy use. RESULTS: The rate of proton therapy use increased significantly from 2.3% in 2004 to 5.2% in 2011 and 4.8% in 2012 (P value for trend <.0001). Proton therapy for prostate cancer was much more likely to be delivered at an academic compared with nonacademic center and to patients who were white, younger, healthier, from metropolitan areas, from zip codes with higher median household incomes, and who did not have an advanced stage of or high-grade disease (all P<.0001). Compared with white patients, those who were black and Hispanic were found to be significantly less likely to receive proton therapy even after robust multivariable adjustments (adjusted odds ratio, 0.20 [95% confidence interval, 0.18-0.22; P<.0001] and adjusted odds ratio, 0.57 [95% confidence interval, 0.48-0.66; P<.0001], respectively). CONCLUSIONS: The use of proton therapy to treat patients with prostate cancer more than doubled from 2004 to 2012, with striking racial disparities in its use noted despite robust multivariable adjustments. Long-term follow-up is needed to determine whether the increased use of proton therapy for prostate cancer is justified, and ongoing efforts should be made to ensure equal access to resource-limited oncologic therapies. Cancer 2016;122:1505-12. © 2016 American Cancer Society.

National sociodemographic disparities in the treatment of high-risk prostate cancer: Do academic cancer centers perform better than community cancer centers?

BACKGROUND: Most major cancer organizations seek to reduce sociodemographic disparities in high-risk cancers partly by increasing access to theoretically high-quality, academic-oriented cancer care. The objective of this study was to determine whether academic centers have less sociodemographic treatment disparities than community centers using high-risk prostate cancer as a test case. METHODS: The National Cancer Data Base was used to identify 138,019 patients who were diagnosed with nonmetastatic, high-risk prostate cancer from 2004 to 2012. Multivariable logistic analysis was used to identify independent determinants of definitive therapy. The Gray test and multivariable Cox regression were used to analyze the timing of therapy. All analyses were stratified by academic versus community cancer center. RESULTS: Compared with white or privately insured patients, black, Hispanic, and uninsured patients with prostate cancer were less likely to receive definitive therapy at both community centers (adjusted odds ratio: 0.60 [95% confidence interval (CI), 0.56-0.64], 0.69 [95% CI, 0.61-0.78], and 0.25 [95% CI, 0.22-0.30], respectively) and academic cancer centers (adjusted odds ratio: 0.50 [95% CI, 0.46-0.54], 0.56 [95% CI, 0.50-0.64], and 0.31 [95% CI, 0.28-0.36], respectively). Among patients who received definitive therapy, black, Hispanic, and uninsured patients were more likely to experience treatment delays at both community centers (≥15, ≥ 10, and ≥19 days, respectively; all Gray P < .001) and academic centers (≥19, ≥ 11, and ≥18 days, respectively); treatment delays were observed among the aforementioned groups even after multivariable Cox regression analysis (P < .001 for all adjusted hazard ratios). CONCLUSIONS: Nationally, academic cancer centers demonstrate similarly high rates of sociodemographic disparities in cancer treatment patterns as community cancer centers. Making community centers conform to academic center standards may not necessarily reduce treatment disparities. Cancer 2016;122:3371-3377. © 2016 American Cancer Society.

New developments in prostate cancer biomarkers.

PURPOSE OF REVIEW: The initial management of localized prostate cancer is increasingly complex with the identification of a growing number of prognostic subgroups. Molecular and genetic biomarkers have been proposed to help clinicians and patients navigate treatment decisions. RECENT FINDINGS: Three commercially available tests, the Genomic Prostate score, Cell Cycle Progression score, and Genomic Classifier appear to currently have the most supporting data for their use in localized prostate cancer. All three have been shown to identify men at higher risk for poor outcome following radical prostatectomy in retrospective studies whereas the first two have also shown promise in addressing which men might be appropriate for active surveillance. Only the Genomic Classifier has data supporting its use as a predictive marker in addition to a prognostic marker. SUMMARY: Over the past several years, the management of localized prostate cancer has seen the development of several novel biomarkers aimed at improving decision making. Although a lack of prospective validation makes it challenging to know how best to change management based on the results from any of the tests, the growing body of retrospective data suggests significant promise in this arena.

Association between very small tumour size and increased cancer-specific mortality after radical prostatectomy in lymph node-positive prostate cancer.

OBJECTIVE: To determine whether very small prostate cancers present in patients who also have lymph node (LN) metastases represent a particularly aggressive disease variant compared with larger LN-positive tumours. PATIENTS AND METHODS: We identified 37 501 patients diagnosed with prostate cancer between 1988 and 2001 treated with radical prostatectomy within the Surveillance, Epidemiology, and End Results database. The primary study variables were tumour size by largest dimension (stratified into: (i) microscopic focus only or 1 mm; (ii) 2-15 mm; (iii) 16-30 mm; (iv) >30 mm), regional LN involvement, and the corresponding interaction term. We evaluated the risk of 10-year prostate cancer-specific mortality (PCSM) using the Fine and Gray model for competing risks after controlling for race, tumour grade, T stage, receipt of radiation, number of dissected LNs, number of positive LNs, year of diagnosis, and age at diagnosis. RESULTS: The median follow-up was 11.8 years. There was a significant interaction between tumour size and LN involvement (P-interaction <0.001). In the absence of LN involvement (36 561 patients), the risk of 10-year PCSM increased monotonically with increasing tumour size. Among patients with LN involvement (940), those with the smallest tumours had increased 10-year PCSM compared with patients with tumours sized 2-15 mm (24.7% vs 11.8%; adjusted hazard ratio [AHR] 2.84, 95% confidence interval [CI] 1.21-6.71; P = 0.017) or 16-30 mm (24.7% vs 15.5%; AHR 3.12, 95% CI 1.51-6.49; P = 0.002), and similar 10-year PCSM as those with tumours >30 mm (24.7% vs 24.9%; P = 0.156). CONCLUSION: In patients with prostate cancer with LN involvement, very small tumour size may predict for higher PCSM compared with some larger tumours, even after controlling for other prognostic variables. These tumours might be particularly aggressive, beyond what is captured by pathological assessment of tumour grade and stage.

Risk of prostate cancer mortality in men with a history of prior cancer.

OBJECTIVES: To describe outcomes of patients with prostate cancer diagnosed after another malignancy and identify factors associated with prostate cancer death in this population, as little is known about the clinical significance of prostate cancer as a subsequent malignancy. PATIENTS AND METHODS: We studied 18 225 men diagnosed with prostate cancer after another malignancy from 1973 to 2006. We compared demographic and clinical variables, and the proportion of death from prostate cancer vs prior malignancy with t-test and chi-squared analyses. Fine and Gray's regression was used to consider the effect of treatment on prostate cancer death. We then studied a second cohort of 88 013 men with prostate cancer as a first or second malignancy to describe current diagnostic and treatment patterns. RESULTS: One in seven men died from prostate cancer in our first cohort. More died from prostate cancer following colorectal cancer (16.8% vs 13.7%), melanoma (13.4% vs 7.56%), and oral cancer (19.1% vs 4.04%), but fewer following bladder cancer, kidney cancer, lung cancer, leukaemia and non-Hodgkin's lymphoma (all P < 0.001). Prostate cancer treatment was associated with a nearly 50% lower risk of death when high-grade or high-stage (adjusted hazard ratio 0.55, 95% confidence interval [CI] 0.47-0.64). Patients who died from prostate cancer had higher grade and stage disease, and received less treatment than patients who died from prior malignancy. The second cohort showed subsequent prostate cancer had more high-risk disease (36.3% vs 22.2%, P < 0.001) and less prostate cancer treatment (adjusted odds ratio 0.872, 95% CI 0.818-0.930) than primary prostate cancer. CONCLUSIONS: Prostate cancer remains a significant cause of mortality when diagnosed as a subsequent cancer. These results suggest prostate cancer treatment should be seriously considered in patients with prior malignancies, especially those with high-grade or locally advanced prostate cancer.

Variation in National Use of Long-Term ADT by Disease Aggressiveness Among Men With Unfavorable-Risk Prostate Cancer.

BACKGROUND: The current NCCN Clinical Practice Guidelines in Oncology for Prostate Cancer recommend long-term androgen deprivation therapy (ADT) for all men with high-risk prostate cancer treated with external-beam radiation therapy (EBRT). We determined whether the use of long-term ADT varied by the recently defined subcategories of high-risk disease (favorable, other, and very high) versus unfavorable intermediate-risk disease. METHODS: We identified 5,524 patients with unfavorable-risk prostate cancer diagnosed from 2004 to 2007 and managed with EBRT using the SEER-Medicare linked database. Patients were stratified by risk group: unfavorable intermediate-risk, favorable high-risk (previously defined and validated as clinical stage T1c, Gleason score of 4 + 4 = 8, and prostate-specific antigen [PSA] level <10 ng/mL, or clinical stage T1c, Gleason score of 6, and PSA level >20 ng/mL), very-high-risk (clinical stage T3b-T4 or primary Gleason pattern 5), or other high risk (ie, neither favorable nor very high). We used multivariable competing risks regression to estimate the rates of long-term (≥2 years) ADT by group. RESULTS: Men with favorable high-risk prostate cancer were significantly less likely to receive long-term ADT than those with other high-risk disease (15.4% vs 24.6%, adjusted hazard ratio [AHR], 0.68; 95% CI, 0.60-0.76;P<.001), and similarly likely as those with unfavorable intermediate-risk disease (AHR, 1.10; 95% CI, 0.99-1.23;P=.087). Other high-risk disease was less likely to receive long-term ADT than very high-risk cancer (24.6% vs 30.8%; AHR, 0.83; 95% CI, 0.74-0.93;P=.002). CONCLUSIONS: Despite current guidelines, patients with EBRT-managed high-risk prostate cancer received significantly different rates of long-course ADT based on subclassification. Our results suggest that oncologists view these patients as a heterogeneous group with favorable high-risk cancer warranting less aggressive therapy than other high-risk or very high-risk disease.

Evaluating a 4-marker signature of aggressive prostate cancer using time-dependent AUC.

BACKGROUND: We previously identified a protein tumor signature of PTEN, SMAD4, SPP1, and CCND1 that, together with clinical features, was associated with lethal outcomes among prostate cancer patients. In the current study, we sought to validate the molecular model using time-dependent measures of AUC and predictive values for discriminating lethal from non-lethal prostate cancer. METHODS: Using data from the initial study, we fit survival models for men with prostate cancer who were participants in the Physicians' Health Study (PHS; n = 276). Based on these models, we generated prognostic risk scores in an independent population, the Health Professionals Follow-up Study (HPFS; n = 347) to evaluate external validity. In each cohort, men were followed prospectively from cancer diagnosis through 2011 for development of distant metastasis or cancer mortality. We measured protein tumor expression of PTEN, SMAD4, SPP1, and CCND1 on tissue microarrays. RESULTS: During a median of 11.9 and 14.3 years follow-up in the PHS and HPFS cohorts, 24 and 32 men (9%) developed lethal disease. When used as a prognostic factor in a new population, addition of the four markers to clinical variables did not improve discriminatory accuracy through 15 years of follow-up. CONCLUSIONS: Although the four markers have been identified as key biological mediators in metastatic progression, they do not provide independent, long-term prognostic information beyond clinical factors when measured at diagnosis. This finding may underscore the broad heterogeneity in aggressive prostate tumors and highlight the challenges that may result from overfitting in discovery-based research.

Incidence and Predictors of Upgrading and Up Staging among 10,000 Contemporary Patients with Low Risk Prostate Cancer.

PURPOSE: We determined the incidence of pathological upgrading and up staging for contemporary, clinically low risk patients, and identified predictors of having occult, advanced disease to inform the selection of patients for active surveillance. MATERIALS AND METHODS: We studied 10,273 patients in the SEER database diagnosed with clinically low risk disease (cT1c/T2a, prostate specific antigen less than 10 ng/ml, Gleason 3 + 3 = 6) in 2010 to 2011 and treated with prostatectomy. The primary outcome was the incidence of upgrading to pathological Gleason score 7-10 or up staging to pathological T3-T4/N1 disease. Multivariable logistic regression of cases with complete biopsy data (5,581) identified significant predictors of upgrading or up staging, which were then used to create a risk stratification table. RESULTS: At prostatectomy 44% of cases were upgraded and 9.7% were up staged. Multivariable analysis of 5,581 patients showed age, prostate specific antigen and percent positive cores (all p < 0.001) but not race were associated with occult, advanced disease. With these variables dichotomized at the median, age older than 60 years (AOR 1.39), prostate specific antigen greater than 5.0 ng/ml (AOR 1.28) and more than 25% positive cores (AOR 1.76) were significantly associated with upgrading (all p < 0.001). Similarly, age older than 60 years (AOR 1.42), prostate specific antigen greater than 5.0 ng/ml (AOR 1.44) and more than 25% positive cores (AOR 2.26) were associated with up staging (all p < 0.001). Overall 60% of 5,581 low risk cases with prostate specific antigen 7.5 to 9.9 ng/ml and more than 25% positive cores were upgraded. This study is limited by possible bias introduced by only using patients selected for prostatectomy. CONCLUSIONS: Nearly half of clinically low risk patients harbor Gleason 7 or greater, or pT3 or greater disease, and should be risk stratified by prostate specific antigen and percent positive cores for consideration of further testing before deciding on active surveillance.