Single-fraction radiation retreatment for bone metastases: role of a rapid access clinic.

OBJECTIVES: This study investigates retreatment rates in single-fraction radiation therapy (SFRT) for painful bone metastasis in patients with limited life expectancy. We compared retreatment-free survival (RFS) in patients from a rapid access bone metastases clinic (RABC) and non-RABC patients, identifying factors associated with retreatment. METHODS: In this observational study, we analysed RABC patients who received SFRT between April 2018 and November 2019, using non-RABC SFRT patients as a comparison group. Patients with prior or perioperative radiation therapy (RT) were excluded. The primary endpoint was same-site and any-site retreatment with RT or surgery. Patient characteristics were compared using χ2 and Student's t-tests, with RFS estimates based on a multistate model considering death as a competing risk using Aalen-Johansen estimates. RESULTS: We identified 151 patients (79 RABC, 72 non-RABC) with 225 treatments (102 RABC, 123 non-RABC) meeting eligibility criteria. Of the 22 (10.8%) same-site retreatments, 5 (22.7%) received surgery, 14 (63.6%) received RT and 3 (13.6%) received both RT and surgery. We found no significant differences in any-site RFS (p=0.97) or same-site RFS (p=0.11). CONCLUSIONS: RFS is high and similar comparable in the RABC and non-RABC cohorts. Retreatment rates are low, even in patients with low Eastern Cooperative Oncology Group scores.

Association of differential censoring with survival and suboptimal control arms among oncology clinical trials.

Differential censoring, which refers to censoring imbalance between treatment arms, may bias the interpretation of survival outcomes in clinical trials. In 146 phase III oncology trials with statistically significant time-to-event surrogate primary endpoints, we evaluated the association between differential censoring in the surrogate primary endpoints, control arm adequacy, and the subsequent statistical significance of overall survival results. Twenty-four (16%) trials exhibited differential censoring that favored the control arm, whereas 15 (10%) exhibited differential censoring that favored the experimental arm. Positive overall survival was more common in control arm differential censoring trials (63%) than in trials without differential censoring (37%) or with experimental arm differential censoring (47%; odds ratio = 2.64, 95% confidence interval = 1.10 to 7.20; P = .04). Control arm differential censoring trials more frequently used suboptimal control arms at 46% compared with 20% without differential censoring and 13% with experimental arm differential censoring (odds ratio = 3.60, 95% confidence interval = 1.29 to 10.0; P = .007). The presence of control arm differential censoring in trials with surrogate primary endpoints, especially in those with overall survival conversion, may indicate an inadequate control arm and should be examined and explained.

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.

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.

Cervicovaginal Microbiota Profiles in Precancerous Lesions and Cervical Cancer among Ethiopian Women.

Although high-risk human papillomavirus infection is a well-established risk factor for cervical cancer, other co-factors within the local microenvironment may play an important role in the development of cervical cancer. The current study aimed to characterize the cervicovaginal microbiota in women with premalignant dysplasia or invasive cervical cancer compared with that of healthy women. The study comprised 120 Ethiopian women (60 cervical cancer patients who had not received any treatment, 25 patients with premalignant dysplasia, and 35 healthy women). Cervicovaginal specimens were collected using either an Isohelix DNA buccal swab or an Evalyn brush, and ribosomal RNA sequencing was used to characterize the cervicovaginal microbiota. Shannon and Simpson diversity indices were used to evaluate alpha diversity. Beta diversity was examined using principal coordinate analysis of weighted UniFrac distances. Alpha diversity was significantly higher in patients with cervical cancer than in patients with dysplasia and in healthy women (p < 0.01). Beta diversity was also significantly different in cervical cancer patients compared with the other groups (weighted UniFrac Bray-Curtis, p < 0.01). Microbiota composition differed between the dysplasia and cervical cancer groups. Lactobacillus iners was particularly enriched in patients with cancer, and a high relative abundance of Lactobacillus species was identified in the dysplasia and healthy groups, whereas Porphyromonas, Prevotella, Bacteroides, and Anaerococcus species predominated in the cervical cancer group. In summary, we identified differences in cervicovaginal microbiota diversity, composition, and relative abundance between women with cervical cancer, women with dysplasia, and healthy women. Additional studies need to be carried out in Ethiopia and other regions to control for variation in sample collection.

Serial Genotyping of the Human Papillomavirus in Cervical Cancer: An Insight Into Virome Dynamics During Chemoradiation Therapy.

PURPOSE: Human papillomavirus (HPV) is the primary driver of cervical cancer. Although studies in other malignancies correlated peripheral blood DNA clearance with favorable outcomes, research on the prognostic value of HPV clearance in gynecologic cancers using intratumoral HPV is scarce. We aimed to quantify the intratumoral HPV virome in patients undergoing chemoradiation therapy (CRT) and associate this with clinical characteristics and outcomes. METHODS AND MATERIALS: This prospective study enrolled 79 patients with stage IB-IVB cervical cancer undergoing definitive CRT. Cervical tumor swabs collected at baseline and week 5 (end of intensity modulated radiation therapy) were sent for shotgun metagenome sequencing and processed via VirMAP, a viral genome sequencing and identification tool for all known HPV types. The data were categorized into HPV groups (16, 18, high risk [HR], and low risk [LR]). We used independent t tests and Wilcoxon signed-rank to compare continuous variables and χ2 and Fisher exact tests to compare categorical variables. Kaplan-Meier survival modeling was performed with log-rank testing. HPV genotyping was verified using quantitative polymerase chain reaction to validate VirMAP results using receiver operating characteristic curve and Cohen's kappa. RESULTS: At baseline, 42%, 12%, 25%, and 16% of patients were positive for HPV 16, HPV 18, HPV HR, and HPV LR, respectively, and 8% were HPV negative. HPV type was associated with insurance status and CRT response. Patients with HPV 16+ and other HPV HR+ tumors were significantly more likely to have a complete response to CRT versus patients with HPV 18 and HPV LR/HPV-negative tumors. Overall HPV viral loads predominantly decreased throughout CRT, except for HPV LR viral load. CONCLUSIONS: Rarer, less well-studied HPV types in cervical tumors are clinically significant. HPV 18 and HPV LR/negative tumors are associated with poor CRT response. This feasibility study provides a framework for a larger study of intratumoral HPV profiling to predict outcomes in patients with cervical cancer.

Immune environment and antigen specificity of the T cell receptor repertoire of malignant ascites in ovarian cancer.

We evaluated the association of disease outcome with T cell immune-related characteristics and T cell receptor (TCR) repertoire in malignant ascites from patients with high-grade epithelial ovarian cancer. Ascitic fluid samples were collected from 47 high-grade epithelial ovarian cancer patients and analyzed using flow cytometry and TCR sequencing to characterize the complementarity determining region 3 TCR ß-chain. TCR functions were analyzed using the McPAS-TCR and VDJ databases. TCR clustering was implemented using Grouping of Lymphocyte Interactions by Paratope Hotspots software. Patients with poor prognosis had ascites characterized by an increased ratio of CD8+ T cells to regulatory T cells, which correlated with an increased productive frequency of the top 100 clones and decreased productive entropy. TCRs enriched in patients with an excellent or good prognosis were more likely to recognize cancer antigens and contained more TCR reads predicted to recognize epithelial ovarian cancer antigens. In addition, a TCR motif that is predicted to bind the TP53 neoantigen was identified, and this motif was enriched in patients with an excellent or good prognosis. Ascitic fluid in high-grade epithelial ovarian cancer patients with an excellent or good prognosis is enriched with TCRs that may recognize ovarian cancer-specific neoantigens, including mutated TP53 and TEAD1. These results suggest that an effective antigen-specific immune response in ascites is vital for a good outcome in high-grade epithelial ovarian cancer.

Metagenomes of rectal swabs in larger, advanced stage cervical cancers have enhanced mucus degrading functionalities and distinct taxonomic structure.

BACKGROUND: Gut microbiome community composition differs between cervical cancer (CC) patients and healthy controls, and increased gut diversity is associated with improved outcomes after treatment. We proposed that functions of specific microbial species adjoining the mucus layer may directly impact the biology of CC. METHOD: Metagenomes of rectal swabs in 41 CC patients were examined by whole-genome shotgun sequencing to link taxonomic structures, molecular functions, and metabolic pathway to patient's clinical characteristics. RESULTS: Significant association of molecular functions encoded by the metagenomes was found with initial tumor size and stage. Profiling of the molecular function abundances and their distributions identified 2 microbial communities co-existing in each metagenome but having distinct metabolism and taxonomic structures. Community A (Clostridia and Proteobacteria predominant) was characterized by high activity of pathways involved in stress response, mucus glycan degradation and utilization of degradation byproducts. This community was prevalent in patients with larger, advanced stage tumors. Conversely, community B (Bacteroidia predominant) was characterized by fast growth, active oxidative phosphorylation, and production of vitamins. This community was prevalent in patients with smaller, early-stage tumors. CONCLUSIONS: In this study, enrichment of mucus degrading microbial communities in rectal metagenomes of CC patients was associated with larger, more advanced stage tumors.

Microbiome Dynamics During Chemoradiation Therapy for Anal Cancer.

PURPOSE: Patients with localized squamous cell carcinoma of the anus (SCCA) who experience treatment toxicity or recurrences have few therapeutic options. Investigation into the microbiome's influence on treatment toxicity and its potential use as a predictive biomarker could improve these patients' outcomes. Our study presents the first longitudinal characterization of the SCCA tumor microbiome and its associations with treatment-related toxicities. METHODS AND MATERIALS: This prospective cohort study included patients with nonmetastatic SCCA receiving standard-of-care chemoradiation therapy. Anorectal swabs of the tumor site were collected before, during, and after treatment. Patient-reported quality-of-life metrics were collected at similar time points. 16S rRNA gene sequencing was used to perform diversity and taxonomic characterization of the SCCA microbiome. Wilcoxon signed-rank tests were used to compare microbial diversity and abundance over time. Wilcoxon rank-sum tests were used to compare microbial profiles of high and low toxicity groups. RESULTS: Twenty-two patients with SCCA were included in this study with a median age of 58.5 years (range, 39-77 years), and 18 (82%) were women. Alpha diversity remained relatively stable throughout chemoradiation therapy except for decreases in the Observed Features (P = .03) index at week 5 relative to baseline. Tumor microbial compositions changed significantly by the end of treatment (P = .03). Differential enrichment of bacteria at specific time points occurred during treatment, including the enrichment of Clostridia at follow-up (vs week 5, q = 0.019) and Corynebacterium at week 5 (vs baseline, q = 0.015; vs follow-up, q = 0.022). Patients experiencing high toxicity at week 5 had higher relative counts of Clostridia, Actinobacteria, and Clostridiales at baseline (P = .03 for all). CONCLUSIONS: The tumor microbiome changes during and after chemoradiation therapy, and patient-reported toxicity levels are associated with patients' microbial profiles. Further studies into these microbial characterizations and toxicity associations will elucidate the tumor microbiome's role in predicting treatment-related outcomes for patients with SCCA.

Diversity and composition of gut microbiome of cervical cancer patients: Do results of 16S rRNA sequencing and whole genome sequencing approaches align?

BACKGROUND: Next generation sequencing has progressed rapidly, characterizing microbial communities beyond culture-based or biochemical techniques. 16S ribosomal RNA gene sequencing (16S) produces reliable taxonomic classifications and relative abundances, while shotgun metagenome sequencing (WMS) allows higher taxonomic and functional resolution at greater cost. The purpose of this study was to determine if 16S and WMS provide congruent information for our patient population from paired fecal microbiome samples. RESULTS: Comparative indices were highly congruent between 16S and WMS. The most abundant genera for 16S and WMS data did not overlap. Overlap was observed at the Phylum level, as expected. However, relative abundances correlated poorly between the two methodologies (all P-value>0.05). Hierarchical clustering of both sequencing analyses identified overlapping enterotypes. Both approaches were in agreement with regard to demographic variables. CONCLUSION: Diversity, evenness and richness are comparable when using 16S and WMS techniques, however relative abundances of individual genera are not. Clinical associations with diversity and evenness metrics were similarly identified with WMS or 16S.

A prospective study of the adaptive changes in the gut microbiome during standard-of-care chemoradiotherapy for gynecologic cancers.

BACKGROUND: A diverse and abundant gut microbiome can improve cancer patients' treatment response; however, the effect of pelvic chemoradiotherapy (CRT) on gut diversity and composition is unclear. The purpose of this prospective study was to identify changes in the diversity and composition of the gut microbiome during and after pelvic CRT. MATERIALS AND METHODS: Rectal swabs from 58 women with cervical, vaginal, or vulvar cancer from two institutions were prospectively analyzed before CRT (baseline), during CRT (weeks 1, 3, and 5), and at first follow-up (week 12) using 16Sv4 rRNA gene sequencing of the V4 hypervariable region of the bacterial 16S rRNA marker gene. 42 of these patients received antibiotics during the study period. Observed operational taxonomic units (OTUs; representative of richness) and Shannon, Simpson, Inverse Simpson, and Fisher diversity indices were used to characterize alpha (within-sample) diversity. Changes over time were assessed using a paired t-test, repeated measures ANOVA, and linear mixed modeling. Compositional changes in specific bacteria over time were evaluated using linear discriminant analysis effect size. RESULTS: Gut microbiome richness and diversity levels continually decreased throughout CRT (mean Shannon diversity index, 2.52 vs. 2.91; all P <0.01), but were at or near baseline levels in 60% of patients by week 12. Patients with higher gut diversity at baseline had the steepest decline in gut microbiome diversity. Gut microbiome composition was significantly altered during CRT, with increases in Proteobacteria and decreases in Clostridiales, but adapted after CRT, with increases in Bacteroides species. CONCLUSION: After CRT, the diversity of the gut microbiomes in this population tended to return to baseline levels by the 12 week follow-up period, but structure and composition remained significantly altered. These changes should be considered when designing studies to analyze the gut microbiome in patients who receive pelvic CRT for gynecologic cancers.

Gut microbiome diversity is an independent predictor of survival in cervical cancer patients receiving chemoradiation.

Diversity of the gut microbiome is associated with higher response rates for cancer patients receiving immunotherapy but has not been investigated in patients receiving radiation therapy. Additionally, current studies investigating the gut microbiome and outcomes in cancer patients may not have adjusted for established risk factors. Here, we sought to determine if diversity and composition of the gut microbiome was independently associated with survival in cervical cancer patients receiving chemoradiation. Our study demonstrates that the diversity of gut microbiota is associated with a favorable response to chemoradiation. Additionally, compositional variation among patients correlated with short term and long-term survival. Short term survivor fecal samples were significantly enriched in Porphyromonas, Porphyromonadaceae, and Dialister, whereas long term survivor samples were significantly enriched in Escherichia Shigella, Enterobacteriaceae, and Enterobacteriales. Moreover, analysis of immune cells from cervical tumor brush samples by flow cytometry revealed that patients with a high microbiome diversity had increased tumor infiltration of CD4+ lymphocytes as well as activated subsets of CD4 cells expressing ki67+ and CD69+ over the course of radiation therapy. Modulation of the gut microbiota before chemoradiation might provide an alternative way to enhance treatment efficacy and improve treatment outcomes in cervical cancer patients.

Patient-Reported Outcome Measures in Pancreatic Cancer Receiving Radiotherapy.

Pancreatic cancer and its treatment often dramatically impact patients' quality of life (QoL). Given this, as well as increased focus on QoL measures in clinical oncology, there has been a rise in the number of instruments that measure patient-reported outcomes (PROs). In this review, we describe the landscape of different PRO instruments pertaining to pancreatic cancer, with specific emphasis on PRO findings related to pancreatic cancer patients receiving radiotherapy (RT). Twenty-five of the most commonly utilized PROs are compared in detail. Notably, most of the PRO tools discussed are not specific to pancreatic cancer but are generic and have been used in various malignancies. Published findings concerning PROs in pancreatic cancer involving RT are also extracted and summarized. Among the measures used, the European Organization for Research and Treatment Cancer QLQ-C30 was the most commonly utilized. We recommend a careful selection of PRO measures in clinical pancreatic cancer research and care and encourage the use of a combination of symptom-specific and global QoL tools to more fully capture patients' perspectives.

Tumor microbial diversity and compositional differences among women in Botswana with high-grade cervical dysplasia and cervical cancer.

INTRODUCTION: We characterized the cervical 16S rDNA microbiome of patients in Botswana with high-grade cervical dysplasia and locally advanced cervical cancer. METHODS: This prospective study included 31 patients: 21 with dysplasia and 10 with cancer. The Shannon diversity index was used to evaluate alpha (intra-sample) diversity, while the UniFrac (weighted and unweighted) and Bray-Curtis distances were employed to evaluate beta (inter-sample) diversity. The relative abundance of microbial taxa was compared among samples using linear discriminant analysis effect size. RESULTS: Alpha diversity was significantly higher in patients with cervical cancer than in patients with cervical dysplasia (P<0.05). Beta diversity also differed significantly (weighted UniFrac Bray-Curtis, P<0.01). Neither alpha diversity (P=0.8) nor beta diversity (P=0.19) varied by HIV status. The results of linear discriminant analysis effect size demonstrated that multiple taxa differed significantly between patients with cervical dysplasia vs cancer. Lachnospira bacteria (in the Clostridia class) were particularly enriched among cervical dysplasia patients, while Proteobacteria (members of the Firmicutes phyla and the Comamonadaceae family) were enriched in patients with cervical cancer. DISCUSSION: The results of our study suggest that differences exist in the diversity and composition of the cervical microbiota between patients with cervical dysplasia and patients with cervical cancer in Botswana. Additional studies are warranted to validate these findings and elucidate their clinical significance among women living in sub-Saharan Africa, as well as other regions of the world.

Patient-Reported GI Outcomes in Patients With Anal Cancer Receiving Modern Chemoradiation.

PURPOSE: Among patients with anal cancer, chemoradiotherapy is often associated with toxicities that diminish quality of life. We describe the GI-related patient-reported outcomes (PROs) of patients with anal cancer receiving chemoradiotherapy to improve patient-physician communication. METHODS: We prospectively followed patients with nonmetastatic squamous cell carcinoma of the anal canal who received definitive chemoradiotherapy. Patients completed the bowel subdomain of the Expanded Prostate Cancer Index Composite (EPIC) questionnaire before treatment and at 4 subsequent timepoints. We used the paired Wilcoxon test to compare EPIC scores at different times. RESULTS: The study included 21 patients; median age was 57 years. Most patients (52%) had T2 and either N0 or N1 disease (81%). Most patients (91%) received chemotherapy with cisplatin-fluorouracil and either intensity-modulated radiotherapy or volumetric modulated arc therapy. Compared with the patients' median overall summary score at baseline (66), their median score at 1 week (82) was higher (P = .009), whereas their median score at 5 weeks (54) was lower (P = .025). The patients' median overall summary score at baseline and at 3 months did not differ (P = .919). Three months after radiotherapy, most patients reported minimal adverse effects compared with baseline. CONCLUSION: The GI-related PROs of patients with anal cancer tend to fluctuate during radiotherapy but return to baseline by 3 months, at which time most patients report few or no residual adverse effects. We provide a clear timeline of GI acute toxicity using sequential PRO measurements that will improve patient-physician communication regarding expectations for cancer treatment.

Coronavirus Goes Viral: Quantifying the COVID-19 Misinformation Epidemic on Twitter.

Background Since the beginning of the coronavirus disease 2019 (COVID-19) epidemic, misinformation has been spreading uninhibited over traditional and social media at a rapid pace. We sought to analyze the magnitude of misinformation that is being spread on Twitter (Twitter, Inc., San Francisco, CA) regarding the coronavirus epidemic.  Materials and methods We conducted a search on Twitter using 14 different trending hashtags and keywords related to the COVID-19 epidemic. We then summarized and assessed individual tweets for misinformation in comparison to verified and peer-reviewed resources. Descriptive statistics were used to compare terms and hashtags, and to identify individual tweets and account characteristics. Results The study included 673 tweets. Most tweets were posted by informal individuals/groups (66%), and 129 (19.2%) belonged to verified Twitter accounts. The majority of included tweets contained serious content (91.2%); 548 tweets (81.4%) included genuine information pertaining to the COVID-19 epidemic. Around 70% of the tweets tackled medical/public health information, while the others were pertaining to sociopolitical and financial factors. In total, 153 tweets (24.8%) included misinformation, and 107 (17.4%) included unverifiable information regarding the COVID-19 epidemic. The rate of misinformation was higher among informal individual/group accounts (33.8%, p: <0.001). Tweets from unverified Twitter accounts contained more misinformation (31.0% vs 12.6% for verified accounts, p: <0.001). Tweets from healthcare/public health accounts had the lowest rate of unverifiable information (12.3%, p: 0.04). The number of likes and retweets per tweet was not associated with a difference in either false or unverifiable content. The keyword "COVID-19" had the lowest rate of misinformation and unverifiable information, while the keywords "#2019_ncov" and "Corona" were associated with the highest amount of misinformation and unverifiable content respectively. Conclusions Medical misinformation and unverifiable content pertaining to the global COVID-19 epidemic are being propagated at an alarming rate on social media. We provide an early quantification of the magnitude of misinformation spread and highlight the importance of early interventions in order to curb this phenomenon that endangers public safety at a time when awareness and appropriate preventive actions are paramount.