A deoxyviolacein-based transposon insertion vector for pigmented tracer studies.

Pigments provide a simple means to rapidly visually ascertain the quantities or presence of specific microbes in a complex community. The selection of pigment-producing colonies that are simple to differentiate from common colony phenotypes provides a high degree of certainty for the identity of pigment-tagged strains. Successful employment of pigment production is dependent on various intrinsic factors related to proper levels of gene expression and pigment production that are not always easy to predict and vary within each microbe. We have constructed a simple transposon system that incorporates the genes for the production of deoxyviolacein, a pigment produced from intracellular reserves of the amino acid tryptophan, to randomly insert these genes throughout the genome. This tool allows the user to select from many thousands of potential sites throughout a bacterial genome for an ideal location to generate the desired amount of pigment. We have applied this system to a small selection of endophytes and other model bacteria to differentiate these strains from complex communities and confirm their presence after several weeks in natural environments. We provide two examples of applications using the pigments to trace strains following introduction into plant tissues or to produce a reporter strain for extracellular nitrogen compound sensing. We recognize that this tool could have far broader utility in other applications and microbes, and describe the methodology for use by the greater scientific community.

Androgen Deprivation Therapy and Outcomes After Radiation Therapy in Black Patients With Prostate Cancer.

Importance: Prostate cancer in Black men compared with White men may be more sensitive to radiation therapy resulting in better outcomes in equal-access settings. The outcomes of androgen-deprivation therapy (ADT) vs radiation therapy itself remains uncharacterized. Objectives: To quantify any outcome modification by receipt of ADT on the association between Black race and prostate cancer outcomes following radiation therapy. Design, Setting, and Participants: This was a retrospective, nationwide cohort study of Black and White patients treated in the US Veterans Healthcare system between 2000 and 2020 receiving definitive radiation for localized prostate cancer. Data were analyzed from January 2000 to December 2020. Exposure: Patient self-identified race and use of ADT defined as any gonadotrophin-releasing hormone agonist or antagonist prescription within 6 months of radiation. Main Outcomes and Measures: Biochemical recurrence (BCR) from time of completion of radiation therapy (prostate-specific antigen nadir plus 2 ng/mL) and development of metastatic disease or prostate cancer mortality (PCSM) from time of recurrence. Results: A total of 26 542 patients (8716 Black men with median [IQR] age of 64 [59-69] years and 17 826 White men with median [IQR] age of 67 [62-72] years) received definitive radiation therapy for nonmetastatic prostate cancer and had complete staging and follow-up data. A total of 5144 patients experienced BCR (3384 White and 1760 Black patients). The cumulative incidence of BCR at 10 years was not significantly different between Black and White men (1602 [22.14%] vs 3099 [20.13%], respectively) with multivariable hazard ratio (HR) of 1.03 (95% CI, 0.97-1.09; P = .33). In men receiving ADT, Black men had an HR for BCR of 0.90 (95% CI, 0.82-0.99; P = .03) compared with White men, and in men not receiving ADT, Black men had an HR of 1.13 (95% CI, 1.05-1.22; P = .002). Black race was associated with a decreased risk of developing metastatic disease (HR, 0.90; 95% CI, 0.82-0.98; P = .02) or PCSM (subdistribution HR, 0.72; 95% CI, 0.63-0.82; P < .001) from time of biochemical recurrence. Conclusions and Relevance: Black patients treated with radiation appear to specifically benefit from the addition of ADT with regard to biochemical control. Additionally, BCR in Black men results in a lower rate of metastatic disease and death from prostate cancer. Future analyses of radiosensitivity in Black men should evaluate for the possibility of outcome modification by ADT.

Adrenal-Permissive Germline HSD3B1 Allele and Prostate Cancer Outcomes.

Importance: The adrenal androgen-metabolizing 3ß-hydroxysteroid dehydrogenase-1 enzyme, encoded by the HSD3B1 gene, catalyzes the rate-limiting step necessary for synthesizing nontesticular testosterone and dihydrotestosterone production. The common adrenal-permissive HSD3B1(1245C) allele is responsible for encoding the 3ß-HSD1 protein with decreased susceptibility to degradation resulting in higher extragonadal androgen synthesis. Retrospective studies have suggested an association of the HSD3B1 adrenal-permissive homozygous genotype with androgen deprivation therapy resistance in prostate cancer. Objective: To evaluate differences in mortality outcomes by HSD3B1 genetic status among men with prostate cancer. Design, Setting, and Participants: This cohort study of patients with prostate cancer who were enrolled in the Million Veteran Program within the Veterans Health Administration (VHA) system between 2011 and 2023 collected genotyping and phenotyping information. Exposure: HSD3B1 genotype status was categorized as AA (homozygous adrenal-restrictive), AC (heterozygous adrenal-restrictive), or CC (homozygous adrenal-permissive). Main Outcomes and Measures: The primary outcome of this study was prostate cancer-specific mortality (PCSM), defined as the time from diagnosis to death from prostate cancer, censored at the date of last VHA follow-up. Secondary outcomes included incidence of metastases and PCSM in predefined subgroups. Results: Of the 5287 participants (median [IQR] age, 69 [64-74] years), 402 (7.6%) had the CC genotype, 1970 (37.3%) had the AC genotype, and 2915 (55.1%) had the AA genotype. Overall, the primary cause of death for 91 patients (1.7%) was prostate cancer. Cumulative incidence of PCSM at 5 years after prostate cancer diagnosis was higher among men with the CC genotype (4.0%; 95% CI, 1.7%-6.2%) compared with the AC genotype (2.1%; 95% CI, 1.3%-2.8%) and AA genotype (1.9%; 95% CI, 1.3%-2.4%) (P = .02). In the 619 patients who developed metastatic disease at any time, the cumulative incidence of PCSM at 5 years was higher among patients with the CC genotype (36.0%; 95% CI, 16.7%-50.8%) compared with the AC genotype (17.9%; 95% CI, 10.5%-24.7%) and AA genotype (18.5%; 95% CI, 12.0%-24.6%) (P = .01). Conclusions and Relevance: In this cohort study of US veterans undergoing treatment for prostate cancer at the VHA, the HSD3B1 CC genotype was associated with inferior outcomes. The HSD3B1 biomarker may help identify patients who may benefit from therapeutic targeting of 3ß-hydroxysteroid dehydrogenase-1 and the androgen-signaling axis.

Genetic risk and likelihood of prostate cancer detection on first biopsy by ancestry.

Despite differences in prostate cancer risk across ancestry groups, relative performance of prostate cancer genetic risks scores (GRS) for positive biopsy prediction in different ancestry groups is unknown. This cross-sectional retrospective analysis examines the association between a polygenic hazard score (PHS290) and risk of prostate cancer diagnosis upon first biopsy in male veterans using 2-sided tests. Our analysis included 36 717 veterans (10 297 of African ancestry). Unadjusted rates of positive first prostate biopsy increased with higher genetic risk (low risk: 34%, high risk: 58%; P < .001). Among men of African ancestry, higher genetic risk was associated with increased prostate cancer detection on first biopsy (odds ratio = 2.18, 95% confidence interval = 1.93 to 2.47), but the effect was stronger among men of European descent (odds ratio = 3.89, 95% confidence interval = 3.62 to 4.18). These findings suggest that incorporating genetic risk into prediction models could better personalize biopsy decisions, although further study is needed to achieve equitable genetic risk stratification among ancestry groups.

Effects of Androgen Deprivation Therapy on Prostate Cancer Outcomes According to Competing Event Risk: Secondary Analysis of a Phase 3 Randomised Trial.

BACKGROUND: Previous studies indicate that the benefit of short-term androgen deprivation therapy (ADT) with radiotherapy (RT) for prostate cancer depends on competing risks. OBJECTIVE: To determine whether a quantitative method to stratify patients by risk for competing events (omega score) could identify subgroups that selectively benefit from ADT. DESIGN, SETTING, AND PARTICIPANTS: An ancillary analysis of NRG/RTOG 9408 phase 3 trial (NCT00002597) involving 1945 prostate cancer patients was conducted. INTERVENTION: Short-term ADT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We applied generalised competing event regression models incorporating age, performance status, comorbidity, T category, Gleason score (GS), and prostate-specific antigen (PSA), to stratify patients according to relative hazards for primary cancer-related events (distant metastasis or prostate cancer death) versus competing noncancer mortality. We tested interactions between ADT and subgroups defined by standard risk criteria versus relative risk (RR) using the omega score. RESULTS AND LIMITATIONS: T2b, higher GS, and higher PSA were associated with an increased RR for cancer-related versus competing mortality events (a higher omega score); increased age and comorbidity were associated with a decreased omega score. Of 996 patients with low-risk/favourable intermediate-risk (FIR) disease, 286 (28.7%) had a high omega score (≥0.314). Of 768 patients with unfavourable intermediate-risk disease, 175 (22.8%) had a low omega score. The overall discordance in risk classification was 26.1%. Both standard criteria and omega score identified significant interactions for the effect of ADT on cancer-related events and late mortality in low- versus high-risk subgroups. Within the low-risk/FIR subgroup, a higher omega score identified patients in whom ADT significantly reduced cancer events and improved event-free survival. Limitations are the need for external/prospective validation and lower RT doses than contemporary standards. CONCLUSIONS: Stratification based on competing event risk is useful for identifying prostate cancer patients who selectively benefit from ADT. PATIENT SUMMARY: We analysed the effectiveness of androgen deprivation therapy (ADT) for localised prostate cancer among patients, defined by the relative risk (RR) for cancer versus noncancer events. Among patients with traditional low-risk/favourable intermediate-risk disease, those with a higher RR benefitted from short-term ADT.

Associations Between Intraductal Prostate Cancer and Metastases Following Radical Prostatectomy in Men With Prostate Cancer in the Veterans Affairs Database.

PURPOSE: Intraductal carcinoma of the prostate (IDC-P) is a relatively unstudied feature present in some prostate cancer (PC) diagnoses with several studies suggesting associations with higher Gleason scores (GS) and earlier time to biochemical recurrence (BCR) after definitive treatment. We looked to identify cases of IDC-P in the Veterans Health Administration (VHA) database and measure associations between IDC-P and pathological stage, BCR, and metastases. METHODS: Patients in the VHA database diagnosed with PC from 2000 to 2017, treated with radical prostatectomy (RP) at the VHA were included in the cohort. BCR was defined as post-RP PSA >0.2 or administration of androgen deprivation therapy (ADT). Time to event was defined as time from RP to event or censor. Differences in cumulative incidences were assessed through Gray's test. Associations with IDC-P and pathologic features at RP, BCR and metastases were assessed through multivariable logistic and Cox regression models. RESULTS: Of 13,913 patients meeting inclusion criteria, 45 patients had IDC-P. Median follow up was 8.8 years from RP. Multivariable logistic regressions showed patients with IDC-P were more likely to have GS ≥8 (Odds Ratio (OR) 1.14, P = .009) and higher T stages (T3 or 4 vs. T1 or 2 OR 1.14, P < .001). In total, 4,318 patients experienced a BCR, and 1,252 patients developed metastases of whom 26 and 12, respectively, had IDC-P. On multivariable regression IDC-P was associated with higher risk of BCR (IDC-P Hazard Ratio (HR) 1.71, P = .006) and metastases (HR 2.84, P < .001). Cumulative incidence of metastases at 4 years for IDC-P and non-IDC-P were 15.9% and 5.5% (P < .001) respectively. CONCLUSIONS: In this analysis, IDC-P was associated with higher Gleason score at RP, shorter time to BCR, and higher rates of metastases. Further studies are warranted to investigate the molecular underpinnings of IDC-P to better guide treatment strategies for this aggressive disease entity.

Prognostic Value of the Intermediate-risk Feature in Men with Favorable Intermediate-risk Prostate Cancer: Implications for Active Surveillance.

Background: Guidelines suggest that active surveillance (AS) may be considered for select patients with favorable intermediate-risk (fIR) prostate cancer. Objective: To compare the outcomes between fIR prostate cancer patients included by Gleason score (GS) or prostate-specific antigen (PSA). Most patients are classified with fIR disease due to either a 3 + 4 = 7 GS (fIR-GS) or a PSA level of 10-20 ng/ml (fIR-PSA). Previous research suggests that inclusion by GS 7 may be associated with worse outcomes. Design setting and participants: We conducted a retrospective cohort study of US veterans diagnosed with fIR prostate cancer from 2001 to 2015. Outcome measurements and statistical analysis: We compared the incidence of metastatic disease, prostate cancer-specific mortality (PCSM), all-cause mortality (ACM), and receipt of definitive treatment between fIR-PSA and fIR-GS patients managed with AS. Outcomes were compared with those of a previously published cohort of patients with unfavorable intermediate-risk disease using cumulative incidence function and Gray's test for statistical significance. Results and limitations: The cohort included 663 men; 404 had fIR-GS (61%) and 249 fIR-PSA (39%). There was no evidence of difference in the incidence of metastatic disease (8.6% vs 5.8%, p = 0.77), receipt of definitive treatment (77.6% vs 81.5%, p = 0.43), PCSM (5.7% vs 2.5%, p = 0.274), and ACM (16.8% vs 19.1%, p = 0.14) between the fIR-PSA and fIR-GS groups at 10 yr. On multivariate regression, unfavorable intermediate-risk disease was associated with higher rates of metastatic disease, PCSM, and ACM. Limitations included varying surveillance protocols. Conclusions: There is no evidence of difference in oncological and survival outcomes between men with fIR-PSA and fIR-GS prostate cancer undergoing AS. Thus, presence of GS 7 disease alone should not exclude patients from consideration of AS. Shared decision-making should be utilized to optimize management for each patient. Patient summary: In this report, we compared the outcomes of men with favorable intermediate-risk prostate cancer in the Veterans Health Administration. We found no significant difference between survival and oncological outcomes.

Androgen deprivation therapy and acute kidney injury in patients with prostate cancer undergoing definitive radiotherapy.

BACKGROUND: Androgen deprivation therapy (ADT) is frequently utilized in conjunction with radiotherapy (RT) in the definitive management of prostate cancer. Prior studies have suggested an association between ADT use and acute kidney injury (AKI), however, these included heterogeneous populations undergoing a variety of treatments and relied on billing codes to ascertain the incidence of AKI. METHODS: We analyzed a cohort of 27,868 veterans undergoing definitive RT + /- ADT for prostate cancer between 2001 and 2015 using the Veterans Affairs Informatics and Computing Infrastructure (VINCI). Exposure was defined as use of ADT within one year of diagnosis. The primary outcome was AKI, defined by an increase in serum creatinine to at least 1.5 times the baseline value. AKIs were classified as mild, moderate, or severe in accordance with international guidelines. A multivariate competing risks model was used to account for demographic and oncologic factors as well as medications and procedures known to influence the risk of AKI. RESULTS: Most (n = 18,754) men received RT alone; 9,114 men received RT + ADT. The incidence of AKI at two years after diagnosis was 10.5% in the RT + ADT group and 7.9% in the RT group (Gray's test p < 0.01). Multivariate analysis confirmed ADT usage was associated with an increased risk for any AKI (SHR = 1.24, 95% CI = 1.14-1.36, p < 0.01). ADT was also associated with an increased risk of mild AKI (SHR = 1.13, 95% CI = 1.01-1.27, p = 0.04) and moderate AKI (SHR = 1.45, 95% CI = 1.20-1.76, p < 0.01), though not severe AKI (SHR = 1.33, 95% CI = 0.93-1.91, p = 0.11). CONCLUSIONS: Our findings confirm that use of ADT is associated with an increased risk of AKI in patients undergoing definitive RT for prostate cancer. Clinicians should be alert to the potential for renal dysfunction in this population.

Quantitative prediction of aspiration risk in head and neck cancer patients treated with radiation therapy.

OBJECTIVE: To determine characteristics most strongly associated with risk for aspiration events among head and neck cancer (HNC) patients undergoing curative intent treatment. MATERIALS AND METHODS: This was a retrospective, cross-sectional study of 106 patients with previously untreated HNC who received definitive or postoperative radiation therapy (RT) +/- systemic therapy with curative intent. Patients who received post-treatment videofluoroscopic swallow study (VFSS) between 2018-2021 were included. Using ordinal multivariable logistic regression, we modeled the effects of age (>60 years vs. ≤60 years), sex, body mass index (BMI) (>20 kg/m2 vs. ≤20 kg/m2), American Joint Committee on Cancer 8th edition stage (I-II vs. III-IVB), treatment with cisplatin (vs. other or no systemic therapy), post-operative status, primary site (oral cavity vs. P16+ oropharynx vs. P16- Mucosal Site vs. other), and quantitative VFSS measures on Penetration-Aspiration Scale (PAS) score. RESULTS AND CONCLUSION: On ordinal multivariable logistic regression, age >60 years (odds ratio (OR): 3.91, 95% confidence interval (CI): 1.29, 11.9), advanced stage (stage III-IVB) (OR: 3.13, 95% CI: 1.23, 7.79), pharyngeal constriction ratio (PCR) >0.25 (OR: 3.65, 95% CI: 1.14, 11.7), and bolus clearance ratio (BCR) > 0.10 (OR: 3.42, 95% CI: 1.20, 9.75) were found to be significant risk factors for higher PAS scores. Patients with ≥ 2 pre-treatment risk factors had statistically significant increased risk for post-treatment aspiration (OR 2.52, 95% CI: 1.31, 4.86) on ordinal logistic regression. This model could be useful to direct high-risk patients toward interventions designed to reduce risk of aspiration events.

Impact of age on treatment response in men with prostate cancer treated with radiotherapy.

Objective: To analyse the effect of age at diagnosis on clinical outcomes of localized prostate cancer (PCa) treated with radiation therapy. Subjects and methods: We identified 12 784 patients with intermediate- or high-risk localized PCa treated with radiation therapy (RT) and neoadjuvant androgen deprivation therapy (ADT) between 2000 and 2015 from nationwide Veterans Affairs data. Patients were grouped into three age categories (≤59, 60-69, and ≥70 years old). Outcomes included immediate PSA response (3-month post-RT PSA and 2-year PSA nadir, grouped into <0.10 ng/ml, 0.10-0.49 ng/ml, and ≥0.50 ng/ml), biochemical recurrence, and PCa-specific mortality. Multivariable regression models included ordinal logistic regression for short-term PSA outcomes, Cox regression for biochemical recurrence, and Fine-Gray competing risks regression for PCa-specific mortality. Results: A total of 2136 patients (17%) were ≤59 years old at diagnosis, 6107 (48%) were 60-69 years old, and 4541 (36%) were ≥70 years old. Median follow-up was 6.3 years. Younger age was associated with greater odds of higher 3-month PSA group (≤59 vs. ≥70: adjusted odds ratio [aOR] 1.90, 95% CI 1.64-2.20; p < 0.001) and higher 2-year PSA nadir group (≤59 vs. ≥70: aOR 1.89, 95% CI 1.62-2.19, p < 0.001). Younger age was associated with greater risk of biochemical recurrence (≤59 vs. ≥70: adjusted hazard ratio 1.45, 95% CI 1.26-1.67, p < 0.001) but not PCa-specific mortality (p = 0.16). Conclusion: In a large nationwide sample of US veterans treated with ADT and RT for localized PCa, younger age was associated with inferior short-term PSA response and higher risk of biochemical recurrence.

An evaluation of trends in the representation of patients by age, sex, and diverse race/ethnic groups in bladder and kidney cancer clinical trials.

OBJECTIVES: To determine the representation of women, minorities, and the elderly groups in clinical trials and whether participation has changed over time. METHODS: Retrospective study in the National Cancer Institute (NCI) Clinical Data Update System and Center for Disease Control and Prevention United States Cancer Statistics 2000 to 2019. We compared cancer incidence proportion to proportion of patients enrolled in an NCI trial when stratified by race/ethnicity, sex, and age. We performed multivariable analysis to determine the odds of participating in a clinical trial in 2015 to 2019 when compared to 2000 to 2004. RESULTS: This study included 14,094 patients, 12,169 (86.3%) non-Hispanic White patients, 662 (4.7%) Black patients, and 660 (4.7%) Hispanic patients. There were 3,701 (26.3%) female patients and 10,393 (73.7%) male patients. For bladder cancer clinical trials, Black patients and Hispanic patients were underrepresented in clinical trials compared to Non-Hispanic White patients (odds ratio [OR] 0.71, 95% confidence interval [CI] 0.57-0.88, P = 0.002) and (OR 0.69, 95%CI 0.54-0.88, P = 0.003), respectively. For kidney cancer trials, Black and Hispanic patients were underrepresented in clinical trials compared to Non-Hispanic White patients (OR 0.42, OR 0.33-0.54, P < 0.001) and (OR 0.68, 95% CI 0.55-0.83, P < 0.001), respectively. Women were underrepresented in kidney cancer trials compared to men (OR 0.80, 95% CI 0.72-0.89) and similarly for bladder cancer trials (OR 0.72, 95% CI 0.64-0.81, P < 0.001). For bladder cancer trials, the participation of Black patients over time (OR 1.04, P = 0.814) and female patients over time (OR 1.03, P = 0.741) were unchanged. For kidney cancer trials, the participation of Black patients over time (OR 1.17, P = 0.293) and female patients over time (OR 1.03, P = 0.663) participation was also unchanged. CONCLUSION: In this study of clinical trials in bladder and kidney cancer, we identified that Blacks, Hispanics, and females were underrepresented. Additionally, Black and female participation was unchanged over the span of 20 years.

Outcomes by time to definitive chemoradiation treatment for patients with muscle-invasive bladder cancer.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has raised concerns about delaying treatment for localized cancer and its impact on long-term outcomes. OBJECTIVE: We aimed to investigate the impact of time to chemoradiation (CRT) on recurrence and survival outcomes for patients with muscle-invasive bladder cancer (MIBC). METHODS: In the national Veterans Affairs' database, we identified patients with urothelial histology, MIBC (T2-4a/N0-3/M0) diagnosed between 2000 to 2018 and treated with definitive CRT. Time to treatment was defined as the number of days between date of diagnosis and start date of CRT. The cohort was stratified into < 90 (early) or ≥ 90 days (delayed) groups. Endpoints of locoregional failure (LRF), distant failure (DF), overall survival (OS), and bladder cancer-specific survival (BCS) were evaluated in multivariable Cox and Fine-Gray models. RESULTS: 305 patients with MIBC underwent CRT - 190 (62.3%) received early CRT, 115 (37.7%) received delayed CRT. Multivariable analysis (including success of transurethral resection of bladder tumor and type of chemotherapy) revealed no difference in recurrence between groups - LRF HR 1.12 (95%CI 0.76-1.67, P = 0.56) and DF HR 1.03 (95%CI 0.70-1.53, P = 0.88). Similarly, there were no differences in survival outcomes. The lack of association was maintained at both earlier and later time cutoffs (60-120 days). CONCLUSIONS: Our findings suggest that a short-term delay in definitive therapy may not affect long-term outcomes for patients with MIBC undergoing CRT. This study does not endorse delays in therapy, but rather provides information to aid patients and clinicians navigate the unique challenges of MIBC care in both pandemic and non-pandemic times.

Bias Reduction through Analysis of Competing Events (BRACE) Correction to Address Cancer Treatment Selection Bias in Observational Data.

PURPOSE: Cancer treatments can paradoxically appear to reduce the risk of noncancer mortality in observational studies, due to residual confounding. Here we introduce a method, Bias Reduction through Analysis of Competing Events (BRACE), to reduce bias in the presence of residual confounding. EXPERIMENTAL DESIGN: BRACE is a novel method for adjusting for bias from residual confounding in proportional hazards models. Using standard simulation methods, we compared BRACE with Cox proportional hazards regression in the presence of an unmeasured confounder. We examined estimator distributions, bias, mean squared error (MSE), and coverage probability. We then estimated treatment effects of high versus low intensity treatments in 36,630 prostate cancer, 4,069 lung cancer, and 7,117 head/neck cancer patients, using the Veterans Affairs database. We analyzed treatment effects on cancer-specific mortality (CSM), noncancer mortality (NCM), and overall survival (OS), using conventional multivariable Cox and propensity score (adjusted using inverse probability weighting) models, versus BRACE-adjusted estimates. RESULTS: In simulations with residual confounding, BRACE uniformly reduced both bias and MSE. In the absence of bias, BRACE introduced bias toward the null, albeit with lower MSE. BRACE markedly improved coverage probability, but with a tendency toward overcorrection for effective but nontoxic treatments. For each clinical cohort, more intensive treatments were associated with significantly reduced hazards for CSM, NCM, and OS. BRACE attenuated OS estimates, yielding results more consistent with findings from randomized trials and meta-analyses. CONCLUSIONS: BRACE reduces bias and MSE when residual confounding is present and represents a novel approach to improve treatment effect estimation in nonrandomized studies.

Metastasis and Mortality in Men With Low- and Intermediate-Risk Prostate Cancer on Active Surveillance.

BACKGROUND: Active surveillance (AS) is a safe treatment option for men with low-risk, localized prostate cancer. However, the safety of AS for patients with intermediate-risk prostate cancer remains unclear. PATIENTS AND METHODS: We identified men with NCCN-classified low-risk and favorable and unfavorable intermediate-risk prostate cancer diagnosed between 2001 and 2015 and initially managed with AS in the Veterans Health Administration. We analyzed progression to definitive treatment, metastasis, prostate cancer-specific mortality (PCSM), and all-cause mortality using cumulative incidences and multivariable competing-risks regression. RESULTS: The cohort included 9,733 men, of whom 1,007 (10.3%) had intermediate-risk disease (773 [76.8%] favorable, 234 [23.2%] unfavorable), followed for a median of 7.6 years. The 10-year cumulative incidence of metastasis was significantly higher for patients with favorable (9.6%; 95% CI, 7.1%-12.5%; P<.001) and unfavorable intermediate-risk disease (19.2%; 95% CI, 13.4%-25.9%; P<.001) than for those with low-risk disease (1.5%; 95% CI, 1.2%-1.9%). The 10-year cumulative incidence of PCSM was also significantly higher for patients with favorable (3.7%; 95% CI, 2.3%-5.7%; P<.001) and unfavorable intermediate-risk disease (11.8%; 95% CI, 6.8%-18.4%; P<.001) than for those with low-risk disease (1.1%; 95% CI, 0.8%-1.4%). In multivariable competing-risks regression, favorable and unfavorable intermediate-risk patients had significantly increased risks of metastasis and PCSM compared with low-risk patients (all P<.001). CONCLUSIONS: Compared with low-risk patients, those with favorable and unfavorable intermediate-risk prostate cancer managed with AS are at increased risk of metastasis and PCSM. AS may be an appropriate option for carefully selected patients with favorable intermediate-risk prostate cancer, though identification of appropriate candidates and AS protocols should be tested in future prospective studies.

Validation of NRG Oncology's prognostic nomograms for oropharyngeal cancer in the Veterans Affairs database.

BACKGROUND: To test whether nomograms developed by NRG Oncology for oropharyngeal squamous cell carcinoma (OPSCC) patients could be validated in an independent population-based sample. METHODS: The authors tested nomograms for estimating progression-free survival (PFS) and overall survival (OS) in patients from the Veterans Health Administration with previously untreated locoregionally advanced OPSCC, diagnosed between 2008 and 2017, managed with definitive radiotherapy with or without adjuvant systemic therapy. Covariates were age, performance status, p16 status, T/N category, smoking history, education history, weight loss, marital status, and anemia. We used multiple imputation to handle missing data and performed sensitivity analyses on complete cases. Validation was assessed via Cox proportional hazards models, log-rank tests, and c-indexes. RESULTS: A total of 4007 patients met inclusion criteria (658 patients had complete data). Median follow-up time was 3.20 years, with 967 progression events and 471 noncancer deaths. Each risk score was associated with poorer outcomes per unit increase (PFS score, hazard ratio [HR], 1.42 [1.37-1.47]; OS score, HR, 1.40 [1.34-1.45]). By risk score quartile, 2-year PFS estimates were 89.2%, 78.5%, 65.8%, and 48.3%; OS estimates were 92.6%, 83.6%, 73.9%, and 51.3%, respectively (P < .01 for all comparisons). C-indices for models of PFS and OS were 0.65 and 0.67, for all patients, respectively (0.69 and 0.73 for complete cases). The nomograms slightly overestimated PFS and OS in the overall cohort but exhibited high agreement in complete cases. CONCLUSIONS: NRG nomograms were effective for predicting PFS and OS for patients with OPSCC, supporting their broader applicability in the OPSCC population undergoing definitive radiotherapy.

Treatment Discontinuation in Patients With Muscle-Invasive Bladder Cancer Undergoing Chemoradiation.

PURPOSE: Chemoradiation (CRT) is a definitive treatment option for muscle-invasive bladder cancer (MIBC). Despite its effectiveness, CRT is underused, in part owing to concerns of tolerability and the need for integrated multidisciplinary care. We investigated factors associated with and the impact of treatment discontinuation in patients with MIBC treated with CRT. METHODS AND MATERIALS: In the US Veterans Affairs' national database, we identified patients with urothelial histology, MIBC (T2-4a/N0-3/M0) diagnosed between 2000 and 2018 and treated with definitive-intent CRT. The primary endpoint of discontinued radiation was evaluated in a multivariable logistic regression. Secondary endpoints of 30-day and 90-day mortality, overall mortality, and nonbladder cancer mortality were evaluated in multivariable models. RESULTS: Of 369 veterans with MIBC who underwent CRT, 30 patients (8.1%) did not complete radiation. The most common reasons for treatment discontinuation included comorbidities or infections necessitating hospital admission (63.3%) and treatment intolerance or declining performance status (26.7%). In multivariable logistic regression, variables associated with radiation discontinuation were creatinine clearance ≤ 50 (odds ratio [OR], 3.93; 95% CI, 1.63-9.50; P = .002), incomplete transurethral resection of bladder tumor (TURBT) (OR, 3.16; 95% CI, 1.15-8.63; P = .02), and nonpreferred chemotherapy (OR, 3.31; 95% CI, 1.31-8.36; P = .01). In the cohort that discontinued radiation, 30-day mortality was 33.3% and 90-day mortality was 50.0%, with the majority of deaths attributed to nonbladder cancer causes. No patient or tumor variables were associated with either endpoint. In the cohort that completed radiation, 30-day mortality was 2.7% and 90-day mortality was 6.8%. In multivariable analysis, radiation discontinuation was associated with worse overall mortality (hazard ratio [HR], 2.48; 95% CI, 1.36-4.50; P = .003) and worse nonbladder cancer mortality (HR, 2.32; 95% CI, 1.24-4.34; P = .008). CONCLUSIONS: With a low rate of treatment discontinuation, CRT is an effective and feasible treatment option for the typically elderly and comorbid population of patients with MIBC. In addition to identified predictors of treatment discontinuation (poor renal function, incomplete TURBT, etc.), further research is required to develop evidence-based guidelines for optimal patient selection.

Improved Prognosis of Treatment Failure in Cervical Cancer with Nontumor PET/CT Radiomics.

Radiomics has been applied to predict recurrence in several disease sites, but current approaches are typically restricted to analyzing tumor features, neglecting nontumor information in the rest of the body. The purpose of this work was to develop and validate a model incorporating nontumor radiomics, including whole-body features, to predict treatment outcomes in patients with previously untreated locoregionally advanced cervical cancer. Methods: We analyzed 127 cervical cancer patients treated definitively with chemoradiotherapy and intracavitary brachytherapy. All patients underwent pretreatment whole-body 18F-FDG PET/CT. To quantify effects due to the tumor itself, the gross tumor volume (GTV) was directly contoured on the PET/CT image. Meanwhile, to quantify effects arising from the rest of the body, the planning target volume (PTV) was deformably registered from each planning CT to the PET/CT scan, and a semiautomated approach combining seed-growing and manual contour review generated whole-body muscle, bone, and fat segmentations on each PET/CT image. A total of 965 radiomic features were extracted for GTV, PTV, muscle, bone, and fat. Ninety-five patients were used to train a Cox model of disease recurrence including both radiomic and clinical features (age, stage, tumor grade, histology, and baseline complete blood cell counts), using bagging and split-sample-validation for feature reduction and model selection. To further avoid overfitting, the resulting models were tested for generalization on the remaining 32 patients, by calculating a risk score based on Cox regression and evaluating the c-index (c-index > 0.5 indicates predictive power). Results: Optimal performance was seen in a Cox model including 1 clinical biomarker (whether or not a tumor was stage III-IVA), 2 GTV radiomic biomarkers (PET gray-level size-zone matrix small area low gray level emphasis and zone entropy), 1 PTV radiomic biomarker (major axis length), and 1 whole-body radiomic biomarker (CT bone root mean square). In particular, stratification into high- and low-risk groups, based on the linear risk score from this Cox model, resulted in a hazard ratio of 0.019 (95% CI, 0.004, 0.082), an improvement over stratification based on clinical stage alone, which had a hazard ratio of 0.36 (95% CI, 0.16, 0.83). Conclusion: Incorporating nontumor radiomic biomarkers can improve the performance of prognostic models compared with using only clinical and tumor radiomic biomarkers. Future work should look to further test these models in larger, multiinstitutional cohorts.

Disparities and trends in the participation of minorities, women, and the elderly in breast, colorectal, lung, and prostate cancer clinical trials.

BACKGROUND: This study was done to determine the representation of minorities, women, and the elderly in National Cancer Institute (NCI) clinical trials. METHODS: This is an analysis in the NCI Clinical Data Update System. Patients were evaluated in breast, colorectal, lung, and prostate cancer trials from 2000 to 2019. Representation in a trial was determined by race/ethnicity, sex, and age. Secondarily, the change in trial participation by multivariable analysis by comparing years 2000 through 2004 to 2015 through 2019 was evaluated. RESULTS: The cohort included 242,720 participants: 197,320 Non-Hispanic White (81.3%), 21,190 Black (8.7%), 11,587 Hispanic (4.8%), and 6880 Asian/Pacific Islander (2.8%). Black and Hispanic patients were underrepresented for colorectal (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.50-0.67; P < .001 and OR, 0.74; 95% CI, 0.64-0.87; P < .001, respectively), lung (OR, 0.83; 95% CI, 0.76-0.91; P < .001 and 0.66; 95% CI, 0.57-0.77; P < .001, respectively), and prostate cancer trials (OR, 0.85; 95% CI, 0.79-0.92; P < .001 and OR, 0.58; 95% CI, 0.51-0.66; P < .001) between 2015 and 2019. The odds of participation in 2015 to 2019 increased among Black patients in breast (OR, 2.19; 95% CI, 2.07-%2.32; P < .001), lung (OR, 1.54; 95% CI, 1.38-1.73; P < .001), and prostate cancer trials (OR, 1.14; 95% CI, 1.04-1.26; P < .001). The odds of participation in a trial among Hispanic patients increased for breast (OR, 3.32; 95% CI, 3.09-3.56; P < .001), colorectal (OR, 2.46; 95% CI, 2.04-2.96; P < .001), lung (OR, 3.88; 95% CI, 3.20-4.69; P < .001), and prostate cancer (OR, 1.70; 95% CI, 1.42-2.04; P = .005). CONCLUSIONS: This study identified that Black and Hispanic patients remain underrepresented in trials, but in recent years, participation has increased. These findings indicate that minority participation has increased over time, but further efforts are needed.

Evaluating Prostate-Specific Antigen Screening for Young African American Men With Cancer.

BACKGROUND: Despite higher risks associated with prostate cancer, young African American men are poorly represented in prostate-specific antigen (PSA) trials, which limits proper evidence-based guidance. We evaluated the impact of PSA screening, alongside primary care provider utilization, on prostate cancer outcomes for these patients. METHODS: We identified African American men aged 40-55 years, diagnosed with prostate cancer between 2004 and 2017 within the Veterans Health Administration. Inverse probability of treatment-weighted propensity scores were used in multivariable models to assess PSA screening on PSA levels higher than 20, Gleason score of 8 or higher, and metastatic disease at diagnosis. Lead-time adjusted Fine-Gray regression evaluated PSA screening on prostate cancer-specific mortality (PCSM), with noncancer death as competing events. All statistical tests were 2-sided. RESULTS: The cohort included 4726 patients. Mean age was 51.8 years, with 84-month median follow-up. There were 1057 (22.4%) with no PSA screening prior to diagnosis. Compared with no screening, PSA screening was associated with statistically significantly reduced odds of PSA levels higher than 20 (odds ratio [OR] = 0.56, 95% confidence interval [CI] = 0.49 to 0.63; P < .001), Gleason score of 8 or higher (OR = 0.78, 95% CI = 0.69 to 0.88; P < .001), and metastatic disease at diagnosis (OR = 0.50, 95% CI = 0.39 to 0.64; P < .001), and decreased PCSM (subdistribution hazard ratio = 0.52, 95% CI = 0.36 to 0.76; P < .001). Primary care provider visits displayed similar effects. CONCLUSIONS: Among young African American men diagnosed with prostate cancer, PSA screening was associated with statistically significantly lower risk of PSA levels higher than 20, Gleason score of 8 or higher, and metastatic disease at diagnosis and statistically significantly reduced risk of PCSM. However, the retrospective design limits precise estimation of screening effects. Prospective studies are needed to validate these findings.

Evaluating the clinical trends and benefits of low-dose computed tomography in lung cancer patients.

BACKGROUND: Despite guideline recommendations, utilization of low-dose computed tomography (LDCT) for lung cancer screening remains low. The driving factors behind these low rates and the real-world effect of LDCT utilization on lung cancer outcomes remain limited. METHODS: We identified patients diagnosed with non-small cell lung cancer (NSCLC) from 2015 to 2017 within the Veterans Health Administration. Multivariable logistic regression assessed the influence of LDCT screening on stage at diagnosis. Lead time correction using published LDCT lead times was performed. Cancer-specific mortality (CSM) was evaluated using Fine-Gray regression with non-cancer death as a competing risk. A lasso machine learning model identified important predictors for receiving LDCT screening. RESULTS: Among 4664 patients, mean age was 67.8 with 58-month median follow-up, 95% CI = [7-71], and 118 patients received ≥1 screening LDCT before NSCLC diagnosis. From 2015 to 2017, LDCT screening increased (0.1%-6.6%, mean = 1.3%). Compared with no screening, patients with ≥1 LDCT were more than twice as likely to present with stage I disease at diagnosis (odds ratio [OR] 2.16 [95% CI 1.46-3.20]) and less than half as likely to present with stage IV (OR 0.38 [CI 0.21-0.70]). Screened patients had lower risk of CSM even after adjusting for LDCT lead time (subdistribution hazard ratio 0.60 [CI 0.42-0.85]). The machine learning model achieved an area under curve of 0.87 and identified diagnosis year and region as the most important predictors for receiving LDCT. White, non-Hispanic patients were more likely to receive LDCT screening, whereas minority, older, female, and unemployed patients were less likely. CONCLUSIONS: Utilization of LDCT screening is increasing, although remains low. Consistent with randomized data, LDCT-screened patients were diagnosed at earlier stages and had lower CSM. LDCT availability appeared to be the main predictor of utilization. Providing access to more patients, including those in diverse racial and socioeconomic groups, should be a priority.