Daniel George

An understanding of the molecular features associated with prostate cancer progression (PCa) and resistance to hormonal therapy is crucial for the identification of new targets that can be utilized to treat advanced disease and prolong patient survival. The glycome, which encompasses all sugar polymers (glycans) synthesized by cells, has remained relatively unexplored in the context of advanced PCa despite the fact that glycans have great potential value as biomarkers and therapeutic targets due to their high density on the cell surface. Using imaging mass spectrometry (IMS), we profiled the N-linked glycans in tumor tissue derived from 131 patients representing the major disease states of PCa to identify glycosylation changes associated with loss of tumor cell differentiation, disease remission, therapy resistance and disease recurrence, as well as neuroendocrine (NE) differentiation which is a major mechanism for therapy failure. Our results indicate significant changes to the glycosylation patterns in various stages of PCa, notably a decrease in tri- and tetraantennary glycans correlating with disease remission, a subsequent increase in these structures with the transition to therapy-resistant PCa, and downregulation of complex N-glycans correlating with NE differentiation. Furthermore, both nonglucosylated and monoglucosylated mannose 9 demonstrate aberrant upregulation in therapy-resistant PCa which may be useful therapeutic targets as these structures are not normally presented in healthy tissue. Our findings characterize changes to the tumor glycome that occur with hormonal therapy and the development of castration-resistant PCa (CRPC), identifying several glycan markers and signatures which may be useful for diagnostic or therapeutic purposes.

The majority of kidney cancers are detected incidentally and typically diagnosed at a localized stage, however, the development of regional or distant disease occurs in one-third of patients. Over 90% of kidney tumors are renal cell carcinomas, of which, clear cell is the most predominate histologic subtype. Von Hippel Lindau (VHL) gene alterations result in the overexpression of growth factors that are central to the pathogenesis of clear cell carcinoma. The therapeutic strategies have revolved around this tumor suppressor gene and have led to the approval of tyrosine kinase inhibitors (TKI) targeting the vascular endothelial growth factor (VEGF) axis. The treatment paradigm shifted with the introduction of immune checkpoint inhibitors (ICI) and programed death-1 (PD-1) inhibition, leading to durable response rates and improved survival. Combinations of TKI and/or ICIs have become the standard of care for advanced clear cell renal cell carcinoma (ccRCC), changing the outlook for patients, with several new and promising therapeutic targets under development.

<h4>Introduction</h4>In patients with nonmetastatic castration-resistant prostate cancer (nmCRPC), prostate-specific antigen doubling time (PSADT) is associated with risk of metastasis and survival. This study evaluated the association of PSADT with clinical and economic outcomes in a real-world setting among patients with nmCRPC not receiving novel hormonal therapy (NHT), using 2-month PSADT thresholds.<h4>Patients and methods</h4>We retrospectively identified Veterans Health Administration patients with nonmetastatic prostate cancer and ≥2 PSA increases after medical/surgical castration (2012-2016). The third measurement was the index (CRPC) date. Patients with ≥3 postindex PSA measurements, including index, were followed until death or ≥12 months until disenrollment, study end, or death, and grouped into 2-month cohorts based on postindex PSADT. Cox regression models assessed association between PSADT, time to metastasis, and death. Healthcare resource utilization and costs were evaluated.<h4>Results</h4>Among 2800 evaluable patients, median follow-up was 30 months and median PSADT was 17 months. Relative to the reference cohort (PSADT >12 months), all cohorts had significantly higher metastasis risk. PSADT ≤10-month cohorts had significantly greater mortality risk than the reference; hazard ratios (95% confidence intervals) ranged from 12.3 (9.2, 16.4) in the PSADT ≤2-month cohort to 1.3 (0.9, 2.0) in the >10 to ≤12-month cohort. Total costs were significantly higher for cohorts up to and including the PSADT >8 to ≤10-month cohort, than for the reference cohort. Mean per patient per month all-cause medical plus pharmacy costs were $6623, $4768, and $4049 in the PSADT ≤2-month, >2 to ≤4-month cohort, and >4 to ≤6-month cohorts, respectively, versus $1911 in the PSADT >12-month cohort (P <0.05).<h4>Conclusion</h4>Most patients with nmCRPC have PSADT >12 months and a long natural history. For those with shorter PSADT, the risk of metastasis, death, and costs increased. These data can help select patients for NHT and conversely those who can safely delay NHT for nmCRPC.

Based on the S-TRAC study, sunitinib was approved as adjuvant therapy for high-risk renal cell carcinoma after nephrectomy; however, the role of perioperative immunotherapy is less clear. Multiple immunotherapy combinations have shown clinical benefit superior to sunitinib in metastatic renal cell carcinoma, but their role in localized or locally advanced renal cell carcinoma still remains controversial. The importance of neoadjuvant immunotherapy in patients with locally advanced RCC is currently under investigation in a large phase 3 clinical trial (PROSPER RCC) and other phase 2 studies investigating PD-1 inhibitors with or without CTLA-4 inhibitors. Multiple ongoing clinical trials (IMmotion010, KEYNOTE-564, and CheckMate 914) are evaluating the adjuvant role of immunotherapy. For the majority of patients with synchronous metastatic renal cell carcinoma, combinations with immunotherapy are now the preferred initial treatment compared to upfront cytoreductive nephrectomy. The timing and benefit of consolidative nephrectomy following immunotherapy combinations are under investigation. Over the next 5 years, these trials will further elucidate optimal timing of immunotherapy in the perioperative setting.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of a research article originally published in Prostate Cancer and Prostatic Diseases. There were few Black men in the clinical trials that led to the approval of the medications abiraterone and enzalutamide. Abiraterone and enzalutamide are the two most commonly used drugs to treat men with advanced prostate cancer that has progressed on traditional hormonal therapy. This type of prostate cancer is called metastatic castration-resistant prostate cancer (mCRPC). Overall, Black men have a higher likelihood of dying from prostate cancer than White men. Researchers wanted to find out if Black men and White men with mCRPC benefitted differently when treated with either abiraterone or enzalutamide. To do this, researchers looked at medical information from the Veterans Health Administration (VHA). The VHA is a large healthcare system for veterans in the US where everyone has equal access to treatment. This was a real-world study, not a clinical trial. This means that researchers looked at what happened when men received the treatments prescribed by their healthcare practitioners. WHAT WERE THE RESULTS?: After accounting for differences in the men's age and health conditions, researchers found that, on average, Black men with mCRPC actually lived 8 months longer than White men with mCRPC. WHAT DO THE RESULTS OF THE STUDY MEAN?: This real-world, US study of men with mCRPC treated with abiraterone or enzalutamide found that Black men lived longer than White men. All men in this study had equal access to healthcare and were treated with either abiraterone or enzalutamide. More research is needed to understand the reasons for this. Understanding these reasons could guide treatment to help men with mCRPC live longer.