Prostate Cancer Recurrence: Examining the Role of Salvage Radiotherapy Field and Risk Factors for Regional Disease Recurrence Captured on 18F-DCFPyL PET/CT.

PURPOSE: The role of elective pelvic nodal irradiation in salvage radiotherapy (sRT) remains controversial. Utilizing 18F-DCFPyL PET/CT, this study aimed to investigate differences in disease distribution after whole pelvic (WPRT) or prostate bed (PBRT) radiotherapy and to identify risk factors for pelvic lymph node (LN) relapse. METHODS: This retrospective study included patients with PSA > 0.1 ng/mL post-radical prostatectomy (RP) or post-RP and sRT who underwent 18F-DCFPyL PET/CT. Disease distribution on 18F-DCFPyL PET/CT after sRT was compared using Chi-square tests. Risk factors were tested for association with pelvic LN relapse after RP and salvage PBRT using logistic regression. RESULTS: 979 18F-DCFPyL PET/CTs performed at our institution between 1/1/2022 - 3/24/2023 were analyzed. There were 246 patients meeting criteria, of which 84 received salvage RT after RP (post-salvage RT group) and 162 received only RP (post-RP group). Salvage PBRT patients (n = 58) had frequent pelvic nodal (53.6%) and nodal-only (42.6%) relapse. Salvage WPRT patients (n = 26) had comparatively lower rates of pelvic nodal (16.7%, p = 0.002) and nodal-only (19.2%, p = 0.04) relapse. The proportion of distant metastases did not differ between the two groups. Multiple patient characteristics, including ISUP grade and seminal vesicle invasion, were associated with pelvic LN disease in the post-RP group. CONCLUSION: At PSA persistence or progression, salvage WPRT resulted in lower rates of nodal involvement than salvage PBRT, but did not reduce distant metastases. Certain risk factors increase the likelihood of pelvic LN relapse after RP and can help inform salvage RT field selection.

Identification and targeting of treatment resistant progenitor populations in T-cell Acute Lymphoblastic Leukemia.

Refractoriness to initial chemotherapy and relapse after remission are the main obstacles to cure in T-cell Acute Lymphoblastic Leukemia (T-ALL). Biomarker guided risk stratification and targeted therapy have the potential to improve outcomes in high-risk T-ALL; however, cellular and genetic factors contributing to treatment resistance remain unknown. Previous bulk genomic studies in T-ALL have implicated tumor heterogeneity as an unexplored mechanism for treatment failure. To link tumor subpopulations with clinical outcome, we created an atlas of healthy pediatric hematopoiesis and applied single-cell multiomic (CITE-seq/snATAC-seq) analysis to a cohort of 40 cases of T-ALL treated on the Children's Oncology Group AALL0434 clinical trial. The cohort was carefully selected to capture the immunophenotypic diversity of T-ALL, with early T-cell precursor (ETP) and Near/Non-ETP subtypes represented, as well as enriched with both relapsed and treatment refractory cases. Integrated analyses of T-ALL blasts and normal T-cell precursors identified a bone-marrow progenitor-like (BMP-like) leukemia sub-population associated with treatment failure and poor overall survival. The single-cell-derived molecular signature of BMP-like blasts predicted poor outcome across multiple subtypes of T-ALL within two independent patient cohorts using bulk RNA-sequencing data from over 1300 patients. We defined the mutational landscape of BMP-like T-ALL, finding that NOTCH1 mutations additively drive T-ALL blasts away from the BMP-like state. We transcriptionally matched BMP-like blasts to early thymic seeding progenitors that have low NR3C1 expression and high stem cell gene expression, corresponding to a corticosteroid and conventional cytotoxic resistant phenotype we observed in ex vivo drug screening. To identify novel targets for BMP-like blasts, we performed in silico and in vitro drug screening against the BMP-like signature and prioritized BMP-like overexpressed cell-surface (CD44, ITGA4, LGALS1) and intracellular proteins (BCL-2, MCL-1, BTK, NF-κB) as candidates for precision targeted therapy. We established patient derived xenograft models of BMP-high and BMP-low leukemias, which revealed vulnerability of BMP-like blasts to apoptosis-inducing agents, TEC-kinase inhibitors, and proteasome inhibitors. Our study establishes the first multi-omic signatures for rapid risk-stratification and targeted treatment of high-risk T-ALL.

Outcomes With First-line PD-1/PD-L1 Inhibition in Advanced Urothelial Cancer: A Single Institution Experience.

BACKGROUND: First-line PD-inhibition in cisplatin-ineligible patients with locally advanced or metastatic urothelial cancer represents a novel clinical setting, with uncertainty concerning second-line outcomes. Specifying second-line treatment and outcomes will provide guidance in this new sequence. We performed a retrospective chart review to document the outcomes of these patients treated at our institution. PATIENTS AND METHODS: Our cohort consisted of 43 patients with advanced urothelial cancer receiving first-line checkpoint inhibition. Baseline factors, programmed death-ligand 1 (PD-L1) status, treatments, and outcomes during and beyond the first line were obtained. Response was scored using Response Evaluation Criteria in Solid Tumors, version 1.1 criteria. Log rank tests were used to compare outcomes in prognostic subgroups, and outcome associations with PD-L1 status were analyzed with Fisher exact tests. RESULTS: A total of 43 patients received first-line atezolizumab or pembrolizumab from June 2014 until June 2018. The median age was 76.8 years, and the population was 74% male, with 60% having visceral metastases. Reasons for cisplatin ineligibility were Eastern Cooperative Oncology Group performance status 2%, 30%; renal insufficiency, 44%, and both, 21%. First-line objective response rate (ORR) was 30%, and complete response was 14%. The median overall survival was 11.7 months. Of 29 patients progressing, 17 received second-line treatment (most commonly, gemcitabine/carboplatin [10 patients]). The second-line response rate was 33%, and the ORR was 11%. The second-line median overall survival was 6.2 months. No association was found between PD-L1 status and outcomes. CONCLUSION: Outcomes with first-line immunotherapy are consistent with historical outcomes. The ORR after first-line checkpoint inhibition falls short of historical comparators; however, the response rate compares favorably to those of chemotherapies used in previous second-line regimens. The older age and poorer performance status may have contributed to second-line outcomes.

The complex relationship between body mass index and response to immune checkpoint inhibition in metastatic melanoma patients.

Despite major improvements in combatting metastatic melanoma since the advent of immunotherapy, the overall survival for patients with advanced disease remains low. Recently, there is a growing number of reports supporting an "obesity paradox," in which patients who are overweight or mildly obese may exhibit a survival benefit in patients who received immune checkpoint inhibitors. We studied the relationship between body mass index and progression-free survival and overall survival in a cohort of 423 metastatic melanoma patients receiving immunotherapy, enrolled and prospectively followed up in the NYU Interdisciplinary Melanoma Cooperative Group database. We analyzed this association stratified by first vs. second or greater-line of treatment and treatment type adjusting for age, gender, stage, lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, number of metastatic sites, and body mass index classification changes. In our cohort, the patients who were overweight or obese did not have different progression-free survival than patients with normal body mass index. Stratifying this cohort by first vs. non-first line immunotherapy revealed a moderate but insignificant association between being overweight or obese and better progression-free survival in patients who received first line. Conversely, an association with worse progression-free survival was observed in patients who received non-first line immune checkpoint inhibitors. Specifically, overweight and obese patients receiving combination immunotherapy had a statistically significant survival benefit, whereas patients receiving the other treatment types showed heterogeneous trends. We caution the scientific community to consider several important points prior to drawing conclusions that could potentially influence patient care, including preclinical data associating obesity with aggressive tumor biology, the lack of congruence amongst several investigations, and the limited reproduced comprehensiveness of these studies.

Pembrolizumab in the treatment of locally advanced or metastatic urothelial carcinoma: clinical trial evidence and experience.

The treatment of advanced urothelial carcinoma (UC) has dramatically changed with the advent of immune checkpoint inhibitors that disrupt the T-cell inhibitory interaction between the programmed cell death (PD)-1 receptor and its ligand (PD-L1). Pembrolizumab, a highly specific, monoclonal antibody directed against PD-1, has demonstrated clinical efficacy as well as a favorable toxicity profile, and has emerged as a new standard of care in the treatment of advanced UC. This review will summarize clinical efficacy from recent trials that led to the approval of pembrolizumab in treating platinum-refractory advanced UC as well as treating patients who are ineligible for first-line cisplatin-containing chemotherapy. While immune checkpoint inhibition has reinvigorated the treatment landscape of advanced UC and generated a great deal of optimism, only a minority of patients benefit. Combination strategies with the goal of increasing response rates are desperately needed as are biomarkers predictive of response.

PD-1/PD-L1 Combinations in Advanced Urothelial Cancer: Rationale and Current Clinical Trials.

Chemotherapy is no longer the only viable option for patients with locally advanced or metastatic urothelial carcinoma. Immunotherapy, as checkpoint inhibition, has received United States Food and Drug Administration approval in the preceding several years, both in the second-line and first-line for cisplatin-ineligible patients. Those who respond often do so durably; however, response rates in the first line are 23% to 24%, and are lower in the second line. With a focus on urothelial carcinoma, this review discusses the tumor microenvironment and its negative influence on anti-tumor immunity, as well as measures to counteract immune suppression or evasion. The review then describes a range of current clinical trials implementing these measures in the form of programmed death-combination therapy, specifically in advanced bladder and urothelial cancers.