Brian C. Baumann

Successful treatment of brain tumors such as glioblastoma multiforme (GBM) is limited in large part by the cumulative dose of Radiation Therapy (RT) that can be safely given and the blood-brain barrier (BBB), which limits the delivery of systemic anticancer agents into tumor tissue. Consequently, the overall prognosis remains grim. Herein, we report our pilot studies in cell culture experiments and in an animal model of GBM in which RT is complemented by PEGylated-gold nanoparticles (GNPs). GNPs significantly increased cellular DNA damage inflicted by ionizing radiation in human GBM-derived cell lines and resulted in reduced clonogenic survival (with dose-enhancement ratio of ~1.3). Intriguingly, combined GNP and RT also resulted in markedly increased DNA damage to brain blood vessels. Follow-up in vitro experiments confirmed that the combination of GNP and RT resulted in considerably increased DNA damage in brain-derived endothelial cells. Finally, the combination of GNP and RT increased survival of mice with orthotopic GBM tumors. Prior treatment of mice with brain tumors resulted in increased extravasation and in-tumor deposition of GNP, suggesting that RT-induced BBB disruption can be leveraged to improve the tumor-tissue targeting of GNP and thus further optimize the radiosensitization of brain tumors by GNP. These exciting results together suggest that GNP may be usefully integrated into the RT treatment of brain tumors, with potential benefits resulting from increased tumor cell radiosensitization to preferential targeting of tumor-associated vasculature.

Importance: Concurrent chemoradiotherapy is the standard-of-care curative treatment for many cancers but is associated with substantial morbidity. Concurrent chemoradiotherapy administered with proton therapy might reduce toxicity and achieve comparable cancer control outcomes compared with conventional photon radiotherapy by reducing the radiation dose to normal tissues. Objective: To assess whether proton therapy in the setting of concurrent chemoradiotherapy is associated with fewer 90-day unplanned hospitalizations (Common Terminology Criteria for Adverse Events, version 4 [CTCAEv4], grade ≥3) or other adverse events and similar disease-free and overall survival compared with concurrent photon therapy and chemoradiotherapy. Design, Setting, and Participants: This retrospective, nonrandomized comparative effectiveness study included 1483 adult patients with nonmetastatic, locally advanced cancer treated with concurrent chemoradiotherapy with curative intent from January 1, 2011, through December 31, 2016, at a large academic health system. Three hundred ninety-one patients received proton therapy and 1092, photon therapy. Data were analyzed from October 15, 2018, through February 1, 2019. Interventions: Proton vs photon chemoradiotherapy. Main Outcomes and Measures: The primary end point was 90-day adverse events associated with unplanned hospitalizations (CTCAEv4 grade ≥3). Secondary end points included Eastern Cooperative Oncology Group (ECOG) performance status decline during treatment, 90-day adverse events of at least CTCAEv4 grade 2 that limit instrumental activities of daily living, and disease-free and overall survival. Data on adverse events and survival were gathered prospectively. Modified Poisson regression models with inverse propensity score weighting were used to model adverse event outcomes, and Cox proportional hazards regression models with weighting were used for survival outcomes. Propensity scores were estimated using an ensemble machine-learning approach. Results: Among the 1483 patients included in the analysis (935 men [63.0%]; median age, 62 [range, 18-93] years), those receiving proton therapy were significantly older (median age, 66 [range, 18-93] vs 61 [range, 19-91] years; P < .01), had less favorable Charlson-Deyo comorbidity scores (median, 3.0 vs 2.0; P < .01), and had lower integral radiation dose to tissues outside the target (mean [SD] volume, 14.1 [6.4] vs 19.1 [10.6] cGy/cc × 107; P < .01). Baseline grade ≥2 toxicity (22% vs 24%; P = .37) and ECOG performance status (mean [SD], 0.62 [0.74] vs 0.68 [0.80]; P = .16) were similar between the 2 cohorts. In propensity score weighted-analyses, proton chemoradiotherapy was associated with a significantly lower relative risk of 90-day adverse events of at least grade 3 (0.31; 95% CI, 0.15-0.66; P = .002), 90-day adverse events of at least grade 2 (0.78; 95% CI, 0.65-0.93; P = .006), and decline in performance status during treatment (0.51; 95% CI, 0.37-0.71; P < .001). There was no difference in disease-free or overall survival. Conclusions and Relevance: In this analysis, proton chemoradiotherapy was associated with significantly reduced acute adverse events that caused unplanned hospitalizations, with similar disease-free and overall survival. Prospective trials are warranted to validate these results.

The NCCN Guidelines for Squamous Cell Skin Cancer provide recommendations for diagnostic workup, clinical stage, and treatment options for patients with cutaneous squamous cell carcinoma. The NCCN panel meets annually to discuss updates to the guidelines based on comments from panel members and the Institutional Review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new surgical recommendation terminology (peripheral and deep en face margin assessment), as well as recent updates on topical prophylaxis, immunotherapy for regional and metastatic disease, and radiation therapy.

The treatment of glioblastoma multiforme, the most prevalent and lethal form of brain cancer in humans, has been limited in part by poor delivery of drugs through the blood-brain barrier and by unclear delineation of the extent of infiltrating tumor margins. Nanoparticles, which selectively accumulate in tumor tissue due to their leaky vasculature and the enhanced permeability and retention effect, have shown promise as both therapeutic and diagnostic agents for brain tumors. In particular, superparamagnetic iron oxide nanoparticles (SPIONs) have been leveraged as T2-weighted MRI contrast agents for tumor detection and imaging; and gold nanoparticles (AuNP) have been demonstrated as radiosensitizers capable of propagating electron and free radical-induced radiation damage to tumor cells. In this study, we investigated the potential applications of novel gold and SPION-loaded micelles (GSMs) coated by polyethylene glycol-polycaprolactone (PEG-PCL) polymer. By quantifying gh2ax DNA damage foci in glioblastoma cell lines, we tested the radiosensitizing efficacy of these GSMs, and found that GSM administration in conjunction with radiation therapy (RT) led to ~2-fold increase in density of double-stranded DNA breaks. For imaging, we used GSMs as a contrast agent for both computed tomography (CT) and magnetic resonance imaging (MRI) studies of stereotactically implanted GBM tumors in a mouse model, and found that MRI but not CT was sufficiently sensitive to detect and delineate tumor borders after administration and accumulation of GSMs. These results suggest that with further development and testing, GSMs may potentially be integrated into both imaging and treatment of brain tumors, serving a theranostic purpose as both an MRI-based contrast agent and a radiosensitizer.

Importance: Locoregional failure for patients with locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemotherapy and is associated with high morbidity and mortality. Adjuvant radiotherapy (RT) can decrease locoregional failure but has not been studied in the chemotherapy era. Objective: To investigate if adjuvant sequential RT plus chemotherapy can improve locoregional recurrence-free survival (LRFS) compared with adjuvant chemotherapy alone. Design, Setting, and Participants: A randomized phase 3 trial was opened to compare adjuvant RT vs sequential chemotherapy plus RT after RC for LABC, but a third arm was added later as a randomized phase 2 trial to compare chemotherapy plus RT vs adjuvant chemotherapy alone, an emerging standard. The intent-to-treat phase 2 trial reported herein enrolled patients from December 2002 to July 2008. Data were analyzed from August 3, 2015, to January 6, 2016. Routine follow-up and surveillance pelvic computed tomographic (CT) scans every 6 months during the first 2 years were performed. The setting was an academic center. Patients with bladder cancer 70 years or younger having 1 or more risk factors (≥pT3b, grade 3, or positive nodes) with negative margins after radical cystectomy plus pelvic lymph node dissection were eligible. Patients had Eastern Cooperative Oncology Group performance status of 0 to 2, no evidence of distant metastases on CT scan of the abdomen and pelvis or on chest imaging, and adequate renal, hepatic, and hematologic function. Ninety-one percent (109 of 120) had ≥ pT3 disease. Interventions: Chemotherapy plus RT included 2 cycles of gemcitabine (1000 mg/m2 intravenously on days 1, 8, and 15) and cisplatin (70 mg/m2 intravenously on day 2) before and after RT to 4500 cGy in 150 cGy twice-daily fractions over 3 weeks using 3-dimensional conformal techniques. Chemotherapy alone included 4 cycles of gemcitabine and cisplatin. Main Outcome and Measure: Locoregional recurrence-free survival. Results: The chemotherapy plus RT arm accrued 75 patients, and the chemotherapy-alone arm accrued 45 patients, with a weighted randomization to speed accrual. Fifty-three percent (64 of 120) had urothelial carcinoma, and 46.7% (56 of 120) had squamous cell carcinoma or other. The arms were balanced except for age (median, 52 vs 55 years; P = .04) and tumor size (mean, 4.9 vs 5.8 cm; P < .01), both favoring chemotherapy plus RT. Two-year outcomes and overall adjusted hazard ratios (HRs) for chemotherapy plus RT vs chemotherapy alone were 96% vs 69% (HR, 0.08; 95% CI, 0.02-0.39; P < .01) for LRFS, 68% vs 56% (HR, 0.53; 95% CI, 0.27-1.06; P = .07) for disease-free survival, and 71% vs 60% (HR, 0.61; 95% CI, 0.33-1.11; P = .11) for overall survival (OS). Five patients (7%) had RT-associated late grade 3 gastrointestinal tract adverse effects in the chemotherapy plus RT arm. Conclusions and Relevance: Adjuvant chemotherapy plus RT was reasonably well tolerated and was associated with significant improvements in LRFS and marginal improvements in disease-free survival vs chemotherapy alone in LABC. The addition of adjuvant RT should be considered for LABC. This regimen warrants further study in phase 3 trials. Trial Registration: clinicaltrials.gov Identifier: NCT01734798.