Lost in the plot: missing visual elements in Kaplan-Meier plots of phase III oncology trials.

Missing visual elements (MVE) in Kaplan-Meier (KM) curves can misrepresent data, preclude curve reconstruction, and hamper transparency. This study evaluated KM plots of phase III oncology trials. MVE were defined as an incomplete y-axis range or missing number at risk table in a KM curve. Surrogate endpoint KM curves were additionally evaluated for complete interpretability, defined by (1) reporting the number of censored patients and (2) correspondence of the disease assessment interval with the number at risk interval. Among 641 trials enrolling 518 235 patients, 116 trials (18%) had MVE in KM curves. Industry sponsorship, larger trials, and more recently published trials were correlated with lower odds of MVE. Only 3% of trials (15 of 574) published surrogate endpoint KM plots with complete interpretability. Improvements in the quality of KM curves of phase III oncology trials, particularly for surrogate endpoints, are needed for greater interpretability, reproducibility, and transparency in oncology research.

Escalated-dose radiotherapy for unresected locally advanced pancreatic cancer: Patterns of care and survival in the United States.

INTRODUCTION: With locally advanced pancreatic cancer (LAPC), uncontrolled local tumor growth frequently leads to mortality. Advancements in radiotherapy (RT) techniques have enabled conformal delivery of escalated-dose RT (EDR), which may have potential local control and overall survival (OS) benefits based on retrospective and early prospective studies. With evidence for EDR emerging, we characterized the adoption of EDR across the United States and its associated outcomes. METHODS: We searched the National Cancer Database for nonsurgically managed LAPC patients diagnosed between 2004 and 2019. Pancreas-directed RT with biologically effective doses (BED10) ≥39 and ≤70 Gy was labeled conventional-dose RT (CDR), and BED10 >70 and ≤132 Gy was labeled EDR. We identified associations of EDR and OS using logistic and Cox regressions, respectively. RESULTS: Among the definitive therapy subset (n = 54,115) of the entire study cohort (n = 91,493), the most common treatments were chemotherapy alone (69%), chemotherapy and radiation (29%), and RT alone (2%). For the radiation therapy subset (n = 16,978), use of pancreas-directed RT remained between 13% and 17% over the study period (ptrend > 0.999). Using multivariable logistic regression, treatment at an academic/research facility (adjusted odds ratio [aOR] 1.46, p < 0.001) and treatment between 2016 and 2019 (aOR 2.54, p < 0.001) were associated with greater receipt of EDR, whereas use of chemotherapy (aOR 0.60, p < 0.001) was associated with less receipt. Median OS estimates for EDR and CDR were 14.5 months and 13.0 months (p < 0.0001), respectively. For radiation therapy subset patients with available survival data (n = 13,579), multivariable Cox regression correlated EDR (adjusted hazard ratio 0.85, 95% confidence interval 0.80-0.91; p < 0.001) with longer OS versus CDR. DISCUSSION AND CONCLUSIONS: Utilization of EDR has increased since 2016, but overall utilization of RT for LAPC has remained at less than one in five patients for almost two decades. These real-world results additionally provide an estimate of effect size of EDR for future prospective trials.

Phase I trial of single-photon emission computed tomography-guided liver-directed radiotherapy for patients with low functional liver volume.

BACKGROUND: Traditional constraints specify that 700 cc of liver should be spared a hepatotoxic dose when delivering liver-directed radiotherapy to reduce the risk of inducing liver failure. We investigated the role of single-photon emission computed tomography (SPECT) to identify and preferentially avoid functional liver during liver-directed radiation treatment planning in patients with preserved liver function but limited functional liver volume after receiving prior hepatotoxic chemotherapy or surgical resection. METHODS: This phase I trial with a 3 + 3 design evaluated the safety of liver-directed radiotherapy using escalating functional liver radiation dose constraints in patients with liver metastases. Dose-limiting toxicities were assessed 6-8 weeks and 6 months after completing radiotherapy. RESULTS: All 12 patients had colorectal liver metastases and received prior hepatotoxic chemotherapy; 8 patients underwent prior liver resection. Median computed tomography anatomical nontumor liver volume was 1584 cc (range = 764-2699 cc). Median SPECT functional liver volume was 1117 cc (range = 570-1928 cc). Median nontarget computed tomography and SPECT liver volumes below the volumetric dose constraint were 997 cc (range = 544-1576 cc) and 684 cc (range = 429-1244 cc), respectively. The prescription dose was 67.5-75 Gy in 15 fractions or 75-100 Gy in 25 fractions. No dose-limiting toxicities were observed during follow-up. One-year in-field control was 57%. One-year overall survival was 73%. CONCLUSION: Liver-directed radiotherapy can be safely delivered to high doses when incorporating functional SPECT into the radiation treatment planning process, which may enable sparing of lower volumes of liver than traditionally accepted in patients with preserved liver function. TRIAL REGISTRATION: NCT02626312.

Redefining FLASH RT: the impact of mean dose rate and dose per pulse in the gastrointestinal tract.

Background: The understanding of how varying radiation beam parameter settings affect the induction and magnitude of the FLASH effect remains limited. Purpose: We sought to evaluate how the magnitude of radiation-induced gastrointestinal (GI) toxicity (RIGIT) depends on the interplay between mean dose rate (MDR) and dose per pulse (DPP). Methods: C57BL/6J mice were subjected to total abdominal irradiation (11-14 Gy single fraction) under conventional irradiation (low DPP and low MDR, CONV) and various combinations of DPP and MDR up to ultra-high-dose-rate (UHDR) beam conditions. The effects of DPP were evaluated for DPPs of 1-6 Gy while the total dose and MDR were kept constant; the effects of MDR were evaluated for the range 0.3- 1440 Gy/s while the total dose and DPP were kept constant. RIGIT was quantified in non-tumor-bearing mice through the regenerating crypt assay and survival assessment. Tumor response was evaluated through tumor growth delay. Results: Within each tested total dose using a constant MDR (>100 Gy/s), increasing DPP led to better sparing of regenerating crypts, with a more prominent effect seen at 12 and 14 Gy TAI. However, at fixed DPPs >4 Gy, similar sparing of crypts was demonstrated irrespective of MDR (from 0.3 to 1440 Gy/s). At a fixed high DPP of 4.7 Gy, survival was equivalently improved relative to CONV for all MDRs from 0.3 Gy/s to 104 Gy/s, but at a lower DPP of 0.93 Gy, increasing MDR produced a greater survival effect. We also confirmed that high DPP, regardless of MDR, produced the same magnitude of tumor growth delay relative to CONV using a clinically relevant melanoma mouse model. Conclusions: This study demonstrates the strong influence that the beam parameter settings have on the magnitude of the FLASH effect. Both high DPP and UHDR appeared independently sufficient to produce FLASH sparing of GI toxicity, while isoeffective tumor response was maintained across all conditions.

UCP2 and pancreatic cancer: conscious uncoupling for therapeutic effect.

Pancreatic cancer has an exaggerated dependence on mitochondrial metabolism, but methods to specifically target the mitochondria without off target effects in normal tissues that rely on these organelles is a significant challenge. The mitochondrial uncoupling protein 2 (UCP2) has potential as a cancer-specific drug target, and thus, we will review the known biology of UCP2 and discuss its potential role in the pathobiology and future therapy of pancreatic cancer.

Stereotactic body radiotherapy with or without selective dismutase mimetic in pancreatic adenocarcinoma: an adaptive, randomised, double-blind, placebo-controlled, phase 1b/2 trial.

BACKGROUND: Stereotactic body radiotherapy (SBRT) has the potential to ablate localised pancreatic ductal adenocarcinoma. Selective dismutase mimetics sensitise tumours while reducing normal tissue toxicity. This trial was designed to establish the efficacy and toxicity afforded by the selective dismutase mimetic avasopasem manganese when combined with ablative SBRT for localised pancreatic ductal adenocarcinoma. METHODS: In this adaptive, randomised, double-blind, placebo-controlled, phase 1b/2 trial, patients aged 18 years or older with borderline resectable or locally advanced pancreatic cancer who had received at least 3 months of chemotherapy and had an Eastern Cooperative Oncology Group performance status of 0-2 were enrolled at six academic sites in the USA. Eligible patients were randomly assigned (1:1), with block randomisation (block sizes of 6-12) with a maximum of 24 patients per group, to receive daily avasopasem (90 mg) or placebo intravenously directly before (ie, within 180 min) SBRT (50, 55, or 60 Gy in five fractions, adaptively assigned in real time by Bayesian estimates of 90-day safety and efficacy). Patients and physicians were masked to treatment group allocation, but not to SBRT dose. The primary objective was to find the optimal dose of SBRT with avasopasem or placebo as determined by the late onset EffTox method. All analyses were done on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, NCT03340974, and is complete. FINDINGS: Between Jan 25, 2018, and April 29, 2020, 47 patients were screened, of whom 42 were enrolled (median age was 71 years [IQR 63-75], 23 [55%] were male, 19 [45%] were female, 37 [88%] were White, three [7%] were Black, and one [2%] each were unknown or other races) and randomly assigned to avasopasem (n=24) or placebo (n=18); the placebo group was terminated early after failing to meet prespecified efficacy parameters. At data cutoff (June 28, 2021), the avasopasem group satisfied boundaries for both efficacy and toxicity. Late onset EffTox efficacy response was observed in 16 (89%) of 18 patients at 50 Gy and six (100%) of six patients at 55 Gy in the avasopasem group, and was observed in three (50%) of six patients at 50 Gy and nine (75%) of 12 patients at 55 Gy in the placebo group, and the Bayesian model recommended 50 Gy or 55 Gy in five fractions with avasopasem for further study. Serious adverse events of any cause were reported in three (17%) of 18 patients in the placebo group and six (25%) of 24 in the avasopasem group. In the placebo group, grade 3 adverse events within 90 days of SBRT were abdominal pain, acute cholangitis, pyrexia, increased blood lactic acid, and increased lipase (one [6%] each); no grade 4 events occurred. In the avasopasem group, grade 3-4 adverse events within 90 days of SBRT were acute kidney injury, increased blood alkaline phosphatase, haematoma, colitis, gastric obstruction, lung infection, abdominal abscess, post-surgical atrial fibrillation, and pneumonia leading to respiratory failure (one [4%] each).There were no treatment-related deaths but one late death in the avasopasem group due to sepsis in the setting of duodenal obstruction after off-study treatment was reported as potentially related to SBRT. INTERPRETATION: SBRT that uses 50 or 55 Gy in five fractions can be considered for patients with localised pancreatic ductal adenocarcinoma. The addition of avasopasem might further enhance disease outcomes. A larger phase 2 trial (GRECO-2, NCT04698915) is underway to validate these results. FUNDING: Galera Therapeutics.

Radiation-induced bone loss in mice is ameliorated by inhibition of HIF-2α in skeletal progenitor cells.

Radiotherapy remains a common treatment modality for cancer despite skeletal complications. However, there are currently no effective treatments for radiation-induced bone loss, and the consequences of radiotherapy on skeletal progenitor cell (SPC) survival and function remain unclear. After radiation, leptin receptor-expressing cells, which include a population of SPCs, become localized to hypoxic regions of the bone and stabilize the transcription factor hypoxia-inducible factor-2α (HIF-2α), thus suggesting a role for HIF-2α in the skeletal response to radiation. Here, we conditionally knocked out HIF-2α in leptin receptor-expressing cells and their descendants in mice. Radiation therapy in littermate control mice reduced bone mass; however, HIF-2α conditional knockout mice maintained bone mass comparable to nonirradiated control animals. HIF-2α negatively regulated the number of SPCs, bone formation, and bone mineralization. To test whether blocking HIF-2α pharmacologically could reduce bone loss during radiation, we administered a selective HIF-2α inhibitor called PT2399 (a structural analog of which was recently FDA-approved) to wild-type mice before radiation exposure. Pharmacological inhibition of HIF-2α was sufficient to prevent radiation-induced bone loss in a single-limb irradiation mouse model. Given that ~90% of patients who receive a HIF-2α inhibitor develop anemia because of off-target effects, we developed a bone-targeting nanocarrier formulation to deliver the HIF-2α inhibitor to mouse bone, to increase on-target efficacy and reduce off-target toxicities. Nanocarrier-loaded PT2399 prevented radiation-induced bone loss in mice while reducing drug accumulation in the kidney. Targeted inhibition of HIF-2α may represent a therapeutic approach for protecting bone during radiation therapy.

Prevalence and implications of significance testing for baseline covariate imbalance in randomised cancer clinical trials: The Table 1 Fallacy.

BACKGROUND: The 'Table 1 Fallacy' refers to the unsound use of significance testing for comparing the distributions of baseline variables between randomised groups to draw erroneous conclusions about balance or imbalance. We performed a cross-sectional study of the Table 1 Fallacy in phase III oncology trials. METHODS: From ClinicalTrials.gov, 1877 randomised trials were screened. Multivariable logistic regressions evaluated predictors of the Table 1 Fallacy. RESULTS: A total of 765 randomised controlled trials involving 553,405 patients were analysed. The Table 1 Fallacy was observed in 25% of trials (188 of 765), with 3% of comparisons deemed significant (59 of 2353), approximating the typical 5% type I error assertion probability. Application of trial-level multiplicity corrections reduced the rate of significant findings to 0.3% (six of 2345 tests). Factors associated with lower odds of the Table 1 Fallacy included industry sponsorship (adjusted odds ratio [aOR] 0.29, 95% confidence interval [CI] 0.18-0.47; multiplicity-corrected P < 0.0001), larger trial size (≥795 versus <280 patients; aOR 0.32, 95% CI 0.19-0.53; multiplicity-corrected P = 0.0008), and publication in a European versus American journal (aOR 0.06, 95% CI 0.03-0.13; multiplicity-corrected P < 0.0001). CONCLUSIONS: This study highlights the persistence of the Table 1 Fallacy in contemporary oncology randomised controlled trials, with one of every four trials testing for baseline differences after randomisation. Significance testing is a suboptimal method for identifying unsound randomisation procedures and may encourage misleading inferences. Journal-level enforcement is a possible strategy to help mitigate this fallacy.

Definitive Liver Radiotherapy for Intrahepatic Cholangiocarcinoma with Extrahepatic Metastases.

Introduction: Tumor-related liver failure (TRLF) is the most common cause of death in patients with intrahepatic cholangiocarcinoma (ICC). Though we previously showed that liver radiotherapy (L-RT) for locally advanced ICC is associated with less frequent TRLF and longer overall survival (OS), the role of L-RT for patients with extrahepatic metastatic disease (M1) remains undefined. We sought to compare outcomes for M1 ICC patients treated with and without L-RT. Methods: We reviewed ICC patients that found to have M1 disease at initial diagnosis at a single institution between 2010 and 2021 who received L-RT, matching them with an institutional cohort by propensity score and a National Cancer Database (NCDB) cohort by frequency technique. The median biologically effective dose was 97.5 Gy (interquartile range 80.5-97.9 Gy) for L-RT. Patients treated with other local therapies or supportive care alone were excluded. We analyzed survival with Cox proportional hazard modeling. Results: We identified 61 patients who received L-RT and 220 who received chemotherapy alone. At median follow-up of 11 months after diagnosis, median OS was 9 months (95% confidence interval [CI] 8-11) and 21 months (CI: 17-26) for patients receiving chemotherapy alone and L-RT, respectively. TRLF was the cause of death more often in the patients who received chemotherapy alone compared to those who received L-RT (82% vs. 47%; p = 0.001). On multivariable propensity score-matched analysis, associations with lower risk of death included duration of upfront chemotherapy (hazard ratio [HR] 0.82; p = 0.005) and receipt of L-RT (HR: 0.40; p = 0.002). The median OS from diagnosis for NCDB chemotherapy alone cohort was shorter than that of the institutional L-RT cohort (9 vs. 22 months; p < 0.001). Conclusion: For M1 ICC, L-RT associated with a lower rate of death due to TRLF and longer OS versus those treated with chemotherapy alone. Prospective studies of L-RT in this setting are warranted.

Incidence of Primary End Point Changes Among Active Cancer Phase 3 Randomized Clinical Trials.

Importance: Primary end point (PEP) changes to an active clinical trial raise questions regarding trial quality and the risk of outcome reporting bias. It is unknown how the frequency and transparency of the reported changes depend on reporting method and whether the PEP changes are associated with trial positivity (ie, the trial met the prespecified statistical threshold for PEP positivity). Objectives: To assess the frequency of reported PEP changes in oncology randomized clinical trials (RCTs) and whether these changes are associated with trial positivity. Design, Setting, and Participants: This cross-sectional study used publicly available data for complete oncology phase 3 RCTs registered in ClinicalTrials.gov from inception through February 2020. Main Outcomes and Measures: The main outcome was change between the initial PEP and the final reported PEP, assessed using 3 methods: (1) history of tracked changes on ClinicalTrials.gov, (2) self-reported changes noted in the article, and (3) changes reported within the protocol, including all available protocol documents. Logistic regression analyses were performed to evaluate whether PEP changes were associated with US Food and Drug Administration approval or trial positivity. Results: Of 755 included trials, 145 (19.2%) had PEP changes found by at least 1 of the 3 detection methods. Of the 145 trials with PEP changes, 102 (70.3%) did not have PEP changes disclosed within the manuscript. There was significant variability in rates of PEP detection by each method (χ2 = 72.1; P < .001). Across all methods, PEP changes were detected at higher rates when multiple versions of the protocol (47 of 148 [31.8%]) were available compared with 1 version (22 of 134 [16.4%]) or no protocol (76 of 473 [16.1%]) (χ2 = 18.7; P < .001). Multivariable analysis demonstrated that PEP changes were associated with trial positivity (odds ratio, 1.86; 95% CI, 1.25-2.82; P = .003). Conclusions and Relevance: This cross-sectional study revealed substantial rates of PEP changes among active RCTs; PEP changes were markedly underreported in published articles and mostly occurred after reported study completion dates. Significant discrepancies in the rate of detected PEP changes call into question the role of increased protocol transparency and completeness in identifying key changes occurring in active trials.

Turning Down Oxygen to Turn Up Inflammation in CAFs.

Pancreatic ductal adenocarcinoma (PDAC) contains a desmoplastic stroma that limits blood perfusion and thus the delivery of nutrients, oxygen, and even therapeutics, creating a hypoxic microenvironment that resists nearly all forms of treatment, including immunomodulating therapy. Cancer-associated fibroblasts (CAF) are the main cellular components and producers of stroma in PDAC. Interestingly, CAFs exist as functionally diverse subpopulations derived from distinct lineages, some of which can be either inflammatory (iCAF) or myofibroblastic (myCAF). While previous work has suggested a link between hypoxia and the iCAF phenotype, direct experimental evidence is lacking. In this issue of Cancer Research, Schwörer and colleagues investigate the role of hypoxia and hypoxia-inducible factor-1α (HIF1α) in maintaining fibroblast heterogeneity and promoting tumor progression in PDAC. The authors use a combination of in vitro and orthotopic techniques to identify a strong role for hypoxia in combination with tumor-derived cytokines in maintaining an iCAF phenotype highlighted by IL6 expression. The authors use an innovative in vitro system to simulate oxygen gradients and use these methods to support their assertions regarding hypoxia as a proinflammatory state. These findings suggest that HIF1α promotes the generation of iCAFs, providing novel insight into CAF heterogeneity. See related article by Schwörer et al., p. 1596.

HPV-related anal cancer is associated with changes in the anorectal microbiome during cancer development.

Background: Squamous cell carcinoma of the anus (SCCA) is a rare gastrointestinal cancer. Factors associated with progression of HPV infection to anal dysplasia and cancer are unclear and screening guidelines and approaches for anal dysplasia are less clear than for cervical dysplasia. One potential contributing factor is the anorectal microbiome. In this study, we aimed to identify differences in anal microbiome composition in the settings of HPV infection, anal dysplasia, and anal cancer in this rare disease. Methods: Patients were enrolled in two prospective studies. Patients with anal dysplasia were part of a cross-sectional cohort that enrolled women with high-grade lower genital tract dysplasia. Anorectal tumor swabs were prospectively collected from patients with biopsy-confirmed locally advanced SCCA prior to receiving standard-of-care chemoradiotherapy (CRT). Patients with high-grade lower genital tract dysplasia without anal dysplasia were considered high-risk (HR Normal). 16S V4 rRNA Microbiome sequencing was performed for anal swabs. Alpha and Beta Diversity and composition were compared for HR Normal, anal dysplasia, and anal cancer. Results: 60 patients with high-grade lower genital tract dysplasia were initially enrolled. Seven patients had concurrent anal dysplasia and 44 patients were considered HR Normal. Anorectal swabs from 21 patients with localized SCCA were included, sequenced, and analyzed in the study. Analysis of weighted and unweighted UniFrac distances demonstrated significant differences in microbial community composition between anal cancer and HR normal (p=0.018). LEfSe identified that all three groups exhibited differential enrichment of specific taxa. Peptoniphilus (p=0.028), Fusobacteria (p=0.0295), Porphyromonas (p=0.034), and Prevotella (p=0.029) were enriched in anal cancer specimens when compared to HR normal. Conclusion: Although alpha diversity was similar between HR Normal, dysplasia and cancer patients, composition differed significantly between the three groups. Increased anorectal Peptoniphilus, Fusobacteria, Porphyromonas, and Prevotella abundance were associated with anal cancer. These organisms have been reported in various gastrointestinal cancers with roles in facilitating the proinflammatory microenvironment and neoplasia progression. Future work should investigate a potential role of microbiome analysis in screening for anal dysplasia and investigation into potential mechanisms of how these microbial imbalances influence the immune system and anal carcinogenesis.

Independent Reproduction of the FLASH Effect on the Gastrointestinal Tract: A Multi-Institutional Comparative Study.

FLASH radiation therapy (RT) is a promising new paradigm in radiation oncology. However, a major question that remains is the robustness and reproducibility of the FLASH effect when different irradiators are used on animals or patients with different genetic backgrounds, diets, and microbiomes, all of which can influence the effects of radiation on normal tissues. To address questions of rigor and reproducibility across different centers, we analyzed independent data sets from The University of Texas MD Anderson Cancer Center and from Lausanne University (CHUV). Both centers investigated acute effects after total abdominal irradiation to C57BL/6 animals delivered by the FLASH Mobetron system. The two centers used similar beam parameters but otherwise conducted the studies independently. The FLASH-enabled animal survival and intestinal crypt regeneration after irradiation were comparable between the two centers. These findings, together with previously published data using a converted linear accelerator, show that a robust and reproducible FLASH effect can be induced as long as the same set of irradiation parameters are used.

Differential Spatial Gene and Protein Expression Associated with Recurrence Following Chemoradiation for Localized Anal Squamous Cell Cancer.

The identification of transcriptomic and protein biomarkers prognosticating recurrence risk after chemoradiation of localized squamous cell carcinoma of the anus (SCCA) has been limited by a lack of available fresh tissue at initial presentation. We analyzed archival FFPE SCCA specimens from pretreatment biopsies prior to chemoradiation for protein and RNA biomarkers from patients with localized SCCA who recurred (N = 23) and who did not recur (N = 25). Tumor cells and the tumor microenvironment (TME) were analyzed separately to identify biomarkers with significantly different expression between the recurrent and non-recurrent groups. Recurrent patients had higher mean protein expression of FoxP3, MAPK-activation markers (BRAF, p38-MAPK) and PI3K/Akt activation (phospho-Akt) within the tumor regions. The TME was characterized by the higher protein expression of immune checkpoint biomarkers such as PD-1, OX40L and LAG3. For patients with recurrent SCCA, the higher mean protein expression of fibronectin was observed in the tumor and TME compartments. No significant differences in RNA expression were observed. The higher baseline expression of immune checkpoint biomarkers, together with markers of MAPK and PI3K/Akt signaling, are associated with recurrence following chemoradiation for patients with localized SCCA. These data provide a rationale towards the application of immune-based therapeutic strategies to improve curative-intent outcomes beyond conventional therapies for patients with SCCA.

Brain Metastases from Biliary Tract Cancer: Case Series and Clinicogenomic Analysis.

BACKGROUND: Limited data from small series have suggested that brain metastases from biliary tract cancers (BrM-BTC) affect ≤2% of patients with BTC. We sought to review our experience with patients with BrM-BTC and to identify associations of tumor-related molecular alterations with outcomes. MATERIALS AND METHODS: A retrospective review of patients with BTC seen at a tertiary referral center from 2005 to 2021 was performed; patients with BrM-BTC were identified, and clinical and molecular data were collected. RESULTS: Twenty-one of 823 patients with BTC (2.6%) developed BrM. For patients with BrM-BTC, median follow-up time was 27.9 months after primary BTC diagnosis and 3.1 months after BrM diagnosis. Median time from primary diagnosis to diagnosis of BrM was 14.4 [range, 1.1-66.0] months. Median overall survival (OS) from primary diagnosis was 31.5 [2.9-99.8] months and median OS from BrM diagnosis was 4.2 [0.2-33.8] months. Patients who underwent BrM-directed therapy trended toward longer OS following BrM diagnosis than patients receiving supportive care only (median 6.5 vs 0.8 months, P = .060). The BrM-BTC cohort was enriched for BRAF (30%), PIK3CA (25%), and GNAS (20%) mutations. patients with BrM-BTC with BRAF mutations trended toward longer OS following BrM diagnosis (median 13.1 vs 4.2 months, P = .131). CONCLUSION: This is the largest series of patients with BrM-BTC to date and provides molecular characterization of this rare subgroup of patients with BTC. Patients with BrM-BTC may be more likely to have BRAF mutations. With advances in targeted therapy for patients with BTC with actionable mutations, continued examination of shifting patterns of failure, with emphasis on BrM, is warranted.

Associative learning contributes to the persistence of fatigue-like behavior in male mice in a model of cancer survivorship.

Persistent fatigue is a debilitating side effect that impacts a significant proportion of cancer survivors for which there is not yet an FDA-approved treatment. While certainly a multi-factorial problem, persistent fatigue could be due, in part, to associations learned during treatment. Therefore, we sought to investigate the role of associative learning in the persistence of fatigue using a preclinical model of cancer survivorship. For this purpose, we used a murine model of human papilloma virus-related head and neck cancer paired with a curative regimen of cisplatin-based chemoradiation in male C57BL/6J mice. Fatigue-like behavior was assessed by measuring variations in voluntary wheel running using a longitudinal design. Treatment robustly decreased voluntary wheel running, and this effect persisted for more than a month posttreatment. However, when wheels were removed during treatment, to minimize treatment-related fatigue, mice showed a more rapid return to baseline running levels. We confirmed that the delayed recovery observed in mice with continual wheel access was not due to increased treatment-related toxicity, in fact running attenuated cisplatin-induced kidney toxicity. Finally, we demonstrated that re-exposure to a treatment-related olfactory cue acutely re-instated fatigue. These data provide the first demonstration that associative processes can modulate the persistence of cancer-related fatigue-like behavior.

Nab-Paclitaxel, Capecitabine, and Radiation Therapy After Induction Chemotherapy in Treating Patients With Locally Advanced and Borderline Resectable Pancreatic Cancer: Phase 1 Trial and Imaging-based Biomarker Validation.

PURPOSE: Effective consolidative chemoradiation (CRT) regimens are lacking. In this phase 1 trial, we evaluated the safety and efficacy of nab-paclitaxel, capecitabine, and radiation therapy after induction chemotherapy in patients with locally advanced and borderline-resectable pancreatic cancer (LAPC and BRPC). Also, we evaluated a computed tomography (CT)-based biomarker of response. METHODS AND MATERIALS: Eligible patients had pathologically confirmed pancreatic ductal adenocarcinoma, underwent computed tomography-imaging, received a diagnosis of LAPC or BRPC, and received induction chemotherapy. Standard 3 + 3 study design was used, with 3 escalating nab-paclitaxel dose levels (50, 75, and 100 mg/m2) with concurrent capecitabine and RT in cohort sizes of 3 starting at the lowest dose. Dose limiting toxicity was defined as grade 3 or higher toxicity. Patients were restaged 4 to 6 weeks post-CRT completion, and surgical resection was offered to those with stable/responsive disease. We scored the tumor interface response (IR) postchemotherapy and post-CRT into type I (remained/became more defined) and type II (became less defined). Overall survival (OS) and progression-free survival (PFS) from time of CRT were estimated using Kaplan-Meier method. P ≤ .05 was considered significant. RESULTS: Twenty-three patients started and finished on protocol (LAPC = 14, BRPC = 9). No grade 3 and 4 toxicities were reported in level 1 (n = 3) or level 2 (n = 3) initial groups. Two patients in the initial level 3 group developed dose limiting toxicity, establishing level 2 dose as the maximal tolerated dose. Level 2 group was expanded for additional 15 patients (for a total of 23 on trial), 5 of whom developed grade 3 toxicities. Seven patients underwent surgical resection. Median OS and PFS were 21.2 and 8.1 months, respectively. Type I IR was associated with better OS (P = .004) and PFS (P = .03) compared with type II IR. CONCLUSIONS: We established the maximum tolerated dose for nab-paclitaxel in a consolidative CRT regimen for pancreatic ductal adenocarcinoma. Preliminary efficacy results warrant phase 2 trial evaluation. IR may be used for personalized treatment.

Mass Transport Model of Radiation Response: Calibration and Application to Chemoradiation for Pancreatic Cancer.

PURPOSE: The benefit of radiation therapy for pancreatic ductal adenocarcinoma (PDAC) remains unclear. We hypothesized that a new mechanistic mathematical model of chemotherapy and radiation response could predict clinical outcomes a priori, using a previously described baseline measurement of perfusion from computed tomography scans, normalized area under the enhancement curve (nAUC). METHODS AND MATERIALS: We simplified an existing mass transport model that predicted cancer cell death by replacing previously unknown variables with averaged direct measurements from randomly selected pathologic sections of untreated PDAC. This allowed using nAUC as the sole model input to approximate tumor perfusion. We then compared the predicted cancer cell death to the actual cell death measured from corresponding resected tumors treated with neoadjuvant chemoradiation in a calibration cohort (n = 80) and prospective cohort (n = 25). After calibration, we applied the model to 2 separate cohorts for pathologic and clinical associations: targeted therapy cohort (n = 101), cetuximab/bevacizumab + radiosensitizing chemotherapy, and standard chemoradiation cohort (n = 81), radiosensitizing chemotherapy to 50.4 Gy in 28 fractions. RESULTS: We established the relationship between pretreatment computed v nAUC to pathologically verified blood volume fraction of the tumor (r = 0.65; P = .009) and fractional tumor cell death (r = 0.97-0.99; P < .0001) in the calibration and prospective cohorts. On multivariate analyses, accounting for traditional covariates, nAUC independently associated with overall survival in all cohorts (mean hazard ratios, 0.14-0.31). Receiver operator characteristic analyses revealed discrimination of good and bad prognostic groups in the cohorts with area under the curve values of 0.64 to 0.71. CONCLUSIONS: This work presents a new mathematical modeling approach to predict clinical response from chemotherapy and radiation for PDAC. Our findings indicate that oxygen/drug diffusion strongly influences clinical responses and that nAUC is a potential tool to select patients with PDAC for radiation therapy.

Patient-Reported Outcomes After Chemoradiation in Patients With Anal Cancer: A Qualitative Analysis.

Purpose: Pelvic chemoradiation therapy (CRT) is the curative therapy for non-metastatic anal cancer, resulting in excellent survival rates. However, anal cancer survivors may experience diminished quality of life (QOL) due to late toxicities from pelvic CRT. Few studies use patient-reported QOL, and few include thematic analyses of the patient experience in their own words. We conducted a survey study with qualitative analysis of free-text responses to explore themes of patient perceptions of their QOL during and after pelvic CRT to inform future interventions, reform patient education, and improve outcomes. Methods and Materials: We surveyed 248 patients with anal cancer treated with definitive intensity modulated radiation and concurrent chemotherapy from 2010 to 2018 who were alive and without recurrence. The survey included the Functional Assessment of Cancer Therapy General 7 item version, questions about satisfaction with preparation and patient education, and an optional free-text response question. Survey free response data were analyzed using the constant comparative method of qualitative analysis. Representative themes were generated. Results: One-hundred and twelve patients (45%) completed surveys. Of these respondents, 84 (75%) answered the free-text question. The median (interquartile range) Functional Assessment of Cancer Therapy General 7 item version score for survey responders (N = 112) was 21 (range, 15-24). Three themes most mentioned by respondents were persistent toxicity effecting QOL (82%), insufficient upfront information about CRT (56%), and gratitude toward care received (35%). Conclusions: Patients described late toxicities that affect QOL after pelvic CRT for anal cancer. This may be partially due to insufficient preparative information and post-treatment support. This study contributes to the literature supporting improved patient education and side effect management to augment long-term QOL for survivors of anal cancer.

Contemporary use and outcomes of radiation and chemotherapy for unresectable pancreatic cancer.

Background: We assessed radiation treatment (RT) use and complications for unresectable pancreatic cancer in the US, comparing conventionally fractionated (CFRT) and stereotactic body radiation treatment (SBRT) to inform real-world expected outcomes and practice. Material and Methods: We analyzed 5,624 patients with non-metastatic, unresectable pancreatic cancer (2,522 older patients age > 65, diagnosed 2006-2013 in Medicare linked data; and 3,102 younger patients age < 65, diagnosed 2006-2016 in MarketScan data), comparing CFRT vs. SBRT vs. chemotherapy alone. Cochran-Armitage tested temporal trends. Fisher's Exact Test and proportional hazards models compared gastrointestinal (GI) complications. Healthcare payments (Consumer Price Index adjusted to 2015) through 12 months were compared using generalized linear regression models with log link and gamma distribution. Results: RT use declined from 55% to 45% of older patients (2006-2013) and 52% to 47% of younger patients (2006-2016) (Ptrend < 0.001 both). Among RT patients, SBRT use increased to 10% of older patients and 12% of younger patients in the most recent years (Ptrend = 0.04 and < 0.001 respectively). Addition of RT was associated with more frequent GI bleeds, strictures, and fistulas (Δ= +3% to 9% excess events, all P ≤ 0.05). Temporal patterns suggested decreasing complications over time (Ptrend = 0.05 and 0.05 for older and younger patients). Among younger patients, there was no difference in GI complications for SBRT vs. CFRT (P > 0.05, all comparisons). Among older patients, increased complications were seen for SBRT in 1-4 fractions vs. CFRT (P < 0.05), but not SBRT in 5 fractions (P = 0.72). Healthcare payments were greatest for SBRT when compared with CFRT or chemotherapy under US Medicare (P < 0.001) and employer-based insurance (P < 0.001). Conclusion: Real-world treatment has shifted toward more selectivity for RT in unresectable pancreatic cancer. However, SBRT uptake and improving trends in complications profiles represent opportunities to optimize current use and benefit. Findings are applicable to inform future comparative and cost effectiveness models of RT for this disease.