Integrative Drug Screening and Multiomic Characterization of Patient-derived Bladder Cancer Organoids Reveal Novel Molecular Correlates of Gemcitabine Response.

BACKGROUND AND OBJECTIVE: Predicting response to therapy for each patient's tumor is critical to improving long-term outcomes for muscle-invasive bladder cancer. This study aims to establish ex vivo bladder cancer patient-derived organoid (PDO) models that are representative of patients' tumors and determine the potential efficacy of standard of care and curated experimental therapies. METHODS: Tumor material was collected prospectively from consented bladder cancer patients to generate short-term PDO models, which were screened against a panel of clinically relevant drugs in ex vivo three-dimensional culture. Multiomic profiling was utilized to validate the PDO models, establish the molecular characteristics of each tumor, and identify potential biomarkers of drug response. Gene expression (GEX) patterns between paired primary tissue and PDO samples were assessed using Spearman's rank correlation coefficients. Molecular correlates of therapy response were identified using Pearson correlation coefficients and Kruskal-Wallis tests with Dunn's post hoc pairwise comparison testing. KEY FINDINGS AND LIMITATIONS: A total of 106 tumors were collected from 97 patients, with 65 samples yielding sufficient material for complete multiomic molecular characterization and PDO screening with six to 32 drugs/combinations. Short-term PDOs faithfully represent the tumor molecular characteristics, maintain diverse cell types, and avoid shifts in GEX-based subtyping that accompany long-term PDO cultures. Utilizing an integrative approach, novel correlations between ex vivo drug responses and genomic alterations, GEX, and protein expression were identified, including a multiomic signature of gemcitabine response. The positive predictive value of ex vivo drug responses and the novel multiomic gemcitabine response signature need to be validated in future studies. CONCLUSIONS AND CLINICAL IMPLICATIONS: Short-term PDO cultures retain the molecular characteristics of tumor tissue and avoid shifts in expression-based subtyping that have plagued long-term cultures. Integration of multiomic profiling and ex vivo drug screening data identifies potential predictive biomarkers, including a novel signature of gemcitabine response. PATIENT SUMMARY: Better models are needed to predict patient response to therapy in bladder cancer. We developed a platform that uses short-term culture to best mimic each patient's tumor and assess potential sensitivity to therapeutics.

Quality of care for dual eligible beneficiaries in the oncology care model.

INTRODUCTION: Dual eligible beneficiaries are a vulnerable population who often experience inferior access to care and outcomes compared to non-dual eligible beneficiaries. The Oncology Care Model (OCM) is an alternative payment model that aims to improve coordination and quality of care in beneficiaries receiving chemotherapy and thus may improve care for dual eligible beneficiaries with cancer. METHODS: We used 100% Medicare claims data from 2014 through 2019 and included beneficiaries with bladder, breast, esophageal, colorectal, kidney, lung, pancreatic, or prostate cancer receiving chemotherapy. We constructed multivariable difference-in-differences regression models to evaluate the effect of OCM participation on healthcare utilization and quality of care at the end-of-life among dual eligible beneficiaries. We also compared healthcare utilization and quality of care outcomes to non-dual eligible beneficiaries. RESULTS: We identified 3,043,944 episodes of care among 1,260,892 unique Medicare beneficiaries. Ten percent of all beneficiaries (n = 126,758) were dual eligible and 64,087 (22%) of episodes among dual eligible patients were in an OCM participating practice. We noted no effect of OCM participation on healthcare utilization or end-of-life quality of care for dual eligible beneficiaries. However, we observed higher rates of hospitalization, emergency department visits, intensive care unit stays, and a lower number of office visits among dual eligible beneficiaries compared to non-dual eligible beneficiaries. CONCLUSIONS: Participation in OCM was not associated with improvements in quality of care or healthcare utilization for dual eligible beneficiaries. Dual eligible beneficiaries experience lower quality of care across several measures compared to non-dual eligible beneficiaries. Focused policies and incentives may be necessary to address disparities within emerging health reforms.

Social Vulnerability and Receipt of Neoadjuvant Chemotherapy in Patients Undergoing Radical Cystectomy for Bladder Cancer.

OBJECTIVE: To evaluate the association between a population-level measure of social determinants of health, the Centers for Disease Control and Prevention Social Vulnerability Index (SVI), and receipt of neoadjuvant chemotherapy in patients with muscle-invasive bladder cancer (MIBC) undergoing radical cystectomy. METHODS: We queried our institutional database for patients with nonmetastatic MIBC treated with radical cystectomy between 2000 and 2022. Patients were assigned an SVI via ZIP code of residence and grouped into quintiles of SVI (ie, least vulnerable to most vulnerable). Multivariable logistic regression was performed to evaluate the association between SVI and receipt of neoadjuvant chemotherapy, adjusting for age, race, gender, and cancer stage. A sub-analysis was performed to evaluate the association between subthemes of SVI (socioeconomic status, household composition/disability, race/ethnicity/language, and housing/transportation) and receipt of neoadjuvant chemotherapy. RESULTS: Of the 978 patients identified, 490 (50.1%) received neoadjuvant chemotherapy. Patients that received neoadjuvant chemotherapy had a lower SVI, were younger, and had >cT2 stage (all, P <.05). The most vulnerable patients had lower odds of receiving neoadjuvant chemotherapy (OR 0.61, 0.39-0.95) compared to the least vulnerable patients. Analysis of subthemes of SVI demonstrated similar associations by socioeconomic status (OR 0.56, 0.36-0.86) and household composition/disability (OR 0.57, 0.33-0.99). CONCLUSION: Adverse social determinants of health, or social vulnerability, are associated with suboptimal and disparate utilization of neoadjuvant chemotherapy in patients with MIBC undergoing radical cystectomy. Strategies for identifying vulnerable populations may allow for more targeted interventions that would improve equity in bladder cancer care.

The 340B Program and oral specialty drugs for advanced prostate cancer.

INTRODUCTION: Expensive oral specialty drugs for advanced prostate cancer can be associated with treatment disparities. The 340B program allows hospitals to purchase medications at discounts, generating savings that can improve care of the socioeconomically disadvantaged. This study assessed the effect of hospital 340B participation on advanced prostate cancer. METHODS: The authors performed a retrospective cohort study of Medicare beneficiaries with advanced prostate cancer from 2012 to 2019. The primary outcome was use of an oral specialty drug. Secondary outcomes included monthly out-of-pocket costs and treatment adherence. We evaluated the effects of 1) hospital 340B participation, 2) a regional measure vulnerability, the social vulnerability index (SVI), and 3) the interaction between hospital 340B participation and SVI on outcomes. RESULTS: There were 2237 and 1100 men who received care at 340B and non-340B hospitals. There was no difference in specialty drug use between 340B and non-340B hospitals, whereas specialty drug use decreased with increased SVI (odds ratio, 0.95, p = .038). However, the interaction between hospital 340B participation and SVI on specialty drug use was not significant. Neither 340B participation, SVI, or their interaction were associated with out-of-pocket costs. Although hospital 340B participation and SVI were not associated with treatment adherence, their interaction was significant (p = .020). This demonstrated that 340B was associated with better adherence among socially vulnerable men. CONCLUSIONS: The 340B program was not associated with specialty drug use in men with advanced prostate cancer. However, among those who were started on therapy, 340B was associated with increased treatment adherence in more socially vulnerable men.

Urologist practice divestment from radiation vault ownership and treatment patterns for prostate cancer.

BACKGROUND: Urologists practicing in single-specialty groups with ownership in radiation vaults are more likely to treat men with prostate cancer. The effect of divestment of vault ownership on treatment patterns is unclear. METHODS: A 20% sample of national Medicare claims was used to perform a retrospective cohort study of men with prostate cancer diagnosed between 2010 and 2019. Urology practices were categorized by radiation vault ownership as nonowners, continuous owners, and divested owners. The primary outcome was use of local treatment, and the secondary outcome was use of intensity-modulated radiation therapy (IMRT). A difference-in-differences framework was used to measure the effect of divestment on outcomes compared to continuous owners. Subgroup analyses assessed outcomes by noncancer mortality risk (high [>50%] vs. low [≤50%]). RESULTS: Among 72 urology practices that owned radiation vaults, six divested during the study. Divestment led to a decrease in treatment compared with those managed at continuously owning practices (difference-in-differences estimate, -13%; p = .03). The use of IMRT decreased, but this was not statistically significant (difference-in-differences estimate, -10%; p = .13). In men with a high noncancer mortality risk, treatment (difference-in-differences estimate, -28%; p < .001) and use of IMRT (difference-in-differences estimate, -27%; p < .001) decreased after divestment. CONCLUSIONS: Urology group divestment from radiation vault ownership led to a decrease in prostate cancer treatment. This decrease was most pronounced in men who had a high noncancer mortality risk. This has important implications for health care reform by suggesting that payment programs that encourage constraints on utilization, when appropriate, may be effective in reducing overtreatment.

The immediate effects of private equity acquisition of urology practices on the management of newly diagnosed prostate cancer.

INTRODUCTION: Some worry that physician practices acquired by private equity may increase the use of services to maximize revenue. We assessed the effects of private equity acquisition on spending, use of treatment, and diagnostic testing in men with prostate cancer. METHODS: We used a 20% sample of national Medicare claims to perform a retrospective cohort study of men with prostate cancer diagnosed from 2014 through 2019. The primary outcome was prostate cancer spending in the first 12 months after diagnosis. Secondary outcomes included the use of treatment and a composite measure of diagnostic testing (e.g., imaging, genomics) in the first 12 months after diagnosis. Multilevel modeling was used to adjust for differences in patient and market characteristics. The effect of practice acquisition on each outcome was assessed using a difference-in-differences design. RESULTS: There were 409 and 4021 men with prostate cancer managed by urologists in acquired and nonacquired practices, respectively. After acquisition, prostate cancer spending was comparable between acquired and nonacquired practices (difference-in-differences estimate $1182, p = 0.36). Acquisition did not affect the use of treatment (difference-in-differences estimate 3.7%, p = 0.30) or the use of diagnostic testing in men who were treated (difference-in-differences -5.5%, p = 0.12) and those managed conservatively (difference-in-differences -2.0%, p = 0.82). CONCLUSIONS: In the year following acquisition of urology practices, private equity did not increase prostate cancer spending, the use of treatment or diagnostic testing in men with prostate cancer. Future work should evaluate the effects of private equity acquisition on practice patterns and quality over a longer time horizon.