Phase I Trial of SPECT-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 (DLTs) were assessed 6-8 weeks and 6 months after completing radiotherapy. RESULTS: All twelve patients had colorectal liver metastases and received prior hepatotoxic chemotherapy. Eight patients underwent prior liver resection. Median computed tomography (CT) anatomical non-tumor liver volume was 1,584 cc (range 764-2,699 cc). Median SPECT functional liver volume was 1,117 cc (range 570-1,928cc). Median non-target CT and SPECT liver volumes below the volumetric dose constraint were 997 cc (range 544-1,576 cc) and 684 cc (range 429-1,244 cc), respectively. The prescription dose was 67.5-75 Gy in 15 fractions or 75-100 Gy in 25 fractions. No DLTs 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.

Long-Term Patient-Reported Dyspareunia After Definitive Chemoradiation for Anal Cancer: Using the Anterior Vaginal Wall as an Organ-at-Risk to Define an Actionable Dosimetric Goal.

Purpose: Chemoradiation therapy (CRT) is the standard treatment for squamous cell carcinoma of the anus (SCCA). This study aimed to investigate the relationship between vaginal dosimetry and long-term patient-reported dyspareunia after treatment. We further aimed to use the anterior vaginal wall (AVW) as an organ at risk to define an actionable dosimetric clinical goal to decrease the risk of patient-reported dyspareunia. Methods and Materials: Women with SCCA treated with intensity modulated radiation therapy-based CRT were surveyed at least 2 years after successfully completing therapy. A Female Sexual Function Index (FSFI) pain subscore ≤4 was used to define dyspareunia. Dosimetric parameters were calculated for both the full vaginal canal and AVW. Multivariable linear regression models were created to identify predictors of FSFI pain subscore using backward selection to identify final variables include in the models. An actionable dosimetric predictor for dyspareunia was established using the Youden index method for cutoff optimization. Results: Of 184 women who were contacted, 90 (49%) returned completed surveys. Of those who completed surveys, 51 (56.7%) reported being sexually active, and 47 had dosimetric data available for review. Of sexually active respondents, 32 (68%) had an FSFI pain subscore ≤4. Multiple regression models were generated using the full vaginal canal and AVW as organs at risk, and both models showed similar predictive relationships with volumetric dose parameters emerging as the best dosimetric predictors for dysparenuia. Age over 65 years was also associated with higher FSFI pain subscores (eg, less pain with intercourse) in both models. AVW V35 Gy < 60% was identified as the optimal cutoff to reduce the risk of patient-reported dyspareunia. Conclusions: Increased dose to the vaginal canal is significantly associated with worse patient-reported dyspareunia following CRT for SCCA. Minimizing dose to the AVW to V35 Gy < 60% may reduce the risk of this quality of life-limiting toxicity. Further prospective evaluation is needed to validate these findings.

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.

Endoscopic Ultrasound-Guided Fiducial Placement for Stereotactic Body Radiation Therapy in Patients with Pancreatic Cancer.

Accurate delivery of stereotactic body radiotherapy (SBRT) to pancreatic tumors relies on successful EUS-guided placement of fiducial markers. The aim of this study is to report the technical feasibility and safety of EUS-guided fiducial placement and to evaluate the characteristics and technical benefit of SBRT in a cohort of patients with pancreatic cancer (PC). A retrospective chart review was performed for all (n = 82) PC patients referred for EUS-guided fiducial placement by a single endosonographer at a tertiary cancer center. Data regarding EUS-related technical details, SBRT characteristics, adverse events, and continuous visibility of fiducials were recorded and analyzed. Most patients included in the study had either locally advanced disease (32 patients, 39%) or borderline resectable disease (29 patients, 35%). Eighty-two PC patients underwent the placement of 230 fiducial markers under EUS guidance. The technical success rate of the fiducial placement was 98%. No immediate EUS-related adverse events were reported. The average time to the simulation CT after fiducial placement was 3.1 days. Of the 216 fiducial markers used for the SBRT delivery, 202 fiducial markers were visible on both the simulation CT and the cone beam CT scan. A median dose of 40cGY was given to all the patients in five fractions. Of these, 41% of the patients reported no SBRT-related toxicities during the follow-up. Fatigue and nausea were the most reported SBRT-related toxicities, which were seen in 35% of the patients post-SBRT. Our results demonstrate that EUS-guided fiducial placement is safe and effective in target volume delineation, facilitating SBRT delivery in PC patients. Further clinical trials are needed to determine the SBRT-related survival benefits in patients with pancreatic cancer.

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.

Tumor-resident Lactobacillus iners confer chemoradiation resistance through lactate-induced metabolic rewiring.

Tumor microbiota can produce active metabolites that affect cancer and immune cell signaling, metabolism, and proliferation. Here, we explore tumor and gut microbiome features that affect chemoradiation response in patients with cervical cancer using a combined approach of deep microbiome sequencing, targeted bacterial culture, and in vitro assays. We identify that an obligate L-lactate-producing lactic acid bacterium found in tumors, Lactobacillus iners, is associated with decreased survival in patients, induces chemotherapy and radiation resistance in cervical cancer cells, and leads to metabolic rewiring, or alterations in multiple metabolic pathways, in tumors. Genomically similar L-lactate-producing lactic acid bacteria commensal to other body sites are also significantly associated with survival in colorectal, lung, head and neck, and skin cancers. Our findings demonstrate that lactic acid bacteria in the tumor microenvironment can alter tumor metabolism and lactate signaling pathways, causing therapeutic resistance. Lactic acid bacteria could be promising therapeutic targets across cancer types.

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.

Prevalence, trends, and characteristics of trials investigating local therapy in contemporary phase 3 clinical cancer research.

BACKGROUND: Although most patients with cancer are treated with local therapy (LT), the proportion of late-phase clinical trials investigating local therapeutic interventions is unknown. The purpose of this study was to determine the proportion, characteristics, and trends of phase 3 cancer clinical trials assessing the therapeutic value of LT over time. METHODS: This was a cross-sectional analysis of interventional randomized controlled trials in oncology published from 2002 through 2020 and registered on ClinicalTrials.gov. Trends and characteristics of LT trials were compared to all other trials. RESULTS: Of 1877 trials screened, 794 trials enrolling 584,347 patients met inclusion criteria. A total of 27 trials (3%) included a primary randomization assessing LT compared with 767 trials (97%) investigating systemic therapy or supportive care. Annual increase in the number of LT trials (slope [m] = 0.28; 95% confidence interval [CI], 0.15-0.39; p < .001) was outpaced by the increase of trials testing systemic therapy or supportive care (m = 7.57; 95% CI, 6.03-9.11; p < .001). LT trials were more often sponsored by cooperative groups (22 of 27 [81%] vs. 211 of 767 [28%]; p < .001) and less often sponsored by industry (5 of 27 [19%] vs. 609 of 767 [79%]; p < .001). LT trials were more likely to use overall survival as primary end point compared to other trials (13 of 27 [48%] vs. 199 of 767 [26%]; p = .01). CONCLUSIONS: In contemporary late-phase oncology research, LT trials are increasingly under-represented, under-funded, and evaluate more challenging end points compared to other modalities. These findings strongly argue for greater resource allocation and funding mechanisms for LT clinical trials. PLAIN LANGUAGE SUMMARY: Most people who have cancer receive treatments directed at the site of their cancer, such as surgery or radiation. We do not know, however, how many trials test surgery or radiation compared to drug treatments (that go all over the body). We reviewed trials testing the most researched strategies (phase 3) completed between 2002 and 2020. Only 27 trials tested local treatments like surgery or radiation compared to 767 trials testing other treatments. Our study has important implications for funding research and understanding cancer research priorities.

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.

Patient-reported Bowel Function and Bowel-related Quality of Life After Pelvic Radiation for Rectal Adenocarcinoma: The Impact of Radiation Fractionation and Surgical Resection.

INTRODUCTION: Multimodality treatment for locally advanced rectal cancer (LARC) can include long-course radiotherapy (LCRT) or short course radiotherapy (SCRT). Nonoperative management is increasingly pursued for those achieving a complete clinical response. Data regarding long-term function and quality-of-life (QOL) are limited. METHODS: Patients with LARC treated with radiotherapy from 2016 to 2020 completed the Functional Assessment of Cancer Therapy- General (FACT-G7), the Low Anterior Resection Syndrome Score (LARS) and the Fecal Incontinence QOL Scale (FIQOL). Univariate and multivariable linear regression analyses identified associations between clinical variables including radiation fractionation and the use of surgery versus non-operative management. RESULTS: Of 204 patients surveyed, 124 (60.8%) responded. Median (interquartile range) time from radiation to survey completion was 30.1 (18.3-43) months. Seventy-nine (63.7%) respondents received LCRT, and 45 (36.3%) received SCRT; 101 (81.5%) respondents underwent surgery, and 23 (18.5%) pursued nonoperative management. There were no differences in LARS, FIQoL or FACT-G7 between patients receiving LCRT versus SCRT. On multivariable analysis, only nonoperative management was associated with lower LARS score signifying less bowel dysfunction. Nonoperative management and female sex were associated with a higher FIQoL score signifying less disruption and distress from fecal incontinence issues. Finally, lower BMI at the time of radiation, female sex, and higher FIQoL score were associated with higher FACT-G7 scores signifying better overall QOL. CONCLUSIONS: These results suggest long-term patient-reported bowel function and QOL may be similar for individuals receiving SCRT and LCRT for the treatment of LARC, but nonoperative management may lead to improved bowel function and QOL.

Resolution of cisplatin-induced fatigue does not require endogenous interleukin-10 in male mice.

Based on previous results showing a pivotal role of endogenous interleukin-10 (IL-10) in the recovery from cisplatin-induced peripheral neuropathy, the present experiments were carried out to determine whether this cytokine plays any role in the recovery from cisplatin-induced fatigue in male mice. Fatigue was measured by decreased voluntary wheel running in mice trained to run in a wheel in response to cisplatin. Mice were treated with a monoclonal neutralizing antibody (IL-10na) administered intranasally during the recovery period to neutralize endogenous IL-10. In the first experiment, mice were treated with cisplatin (2.83 mg/kg/day) for five days and IL-10na (12 µg/day for three days) five days later. In the second experiment, they were treated with cisplatin (2.3 mg/kg/day for 5 days twice at a five-day interval) and IL10na (12 µg/day for three days) immediately after the last injection of cisplatin. In both experiments, cisplatin decreased body weight and reduced voluntary wheel running. However, IL-10na did not impair recovery from these effects. These results show that the recovery from the cisplatin-induced decrease in wheel running does not require endogenous IL-10 in contrast to the recovery from cisplatin-induced peripheral neuropathy.

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.